[RFC 00/21] Replace seqno values with request structures

[RFC 00/21] Replace seqno values with request structures

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

Work in progress for replacing seqno usage with requst structures.

There is a general feeling that it is better to move away from using a simple
integer 'seqno' value to track batch buffer completion. Instead, the request
structure should be used. That provides for much more flexibility going
forwards. Especially which things like a GPU scheduler (which can re-order batch
buffers and hence seqnos after submission to the hardware), Android sync points
and other such features which potentially make seqno usage more and more
complex.

The current set of patches do most of the seqno to request structure conversion.
There are still a couple of direct seqno comparisons in the semaphore code. The
final conversion of a seqno test into a 'completed' flag inside the request
structure is still do to as well. Along with whatever changes are required to
maintain such a flag.

The patches are being posted now to make sure that the various people involved
agree that it is heading in the right direction.

[Patches against drm-intel-nightly tree fetched 11/09/2014]

John Harrison (21):
  Bug: missing i915_seqno_passed() call?
  drm/i915: Remove redundant parameter to i915_gem_object_wait_rendering__tail()
  drm/i915: Ensure OLS & PLR are always in sync
  drm/i915: Add reference count to request structure
  drm/i915: Add helper functions to aid seqno -> request transition
  drm/i915: Replace last_[rwf]_seqno with last_[rwf]_req
  drm/i915: Ensure requests stick around during waits
  drm/i915: Remove 'outstanding_lazy_seqno'
  drm/i915: Make 'i915_gem_check_olr' actually check by request not seqno
  drm/i915: Convert 'last_flip_req' to be a request not a seqno
  drm/i915: Convert i915_wait_seqno to i915_wait_request
  drm/i915: Convert 'i915_add_request' to take a request not a seqno
  drm/i915: Convert mmio_flip::seqno to struct request
  drm/i915: Convert 'flip_queued_seqno' into 'flip_queued_request'
  drm/i915: Convert most 'i915_seqno_passed' calls into 'i915_gem_request_completed'
  drm/i915: Convert __wait_seqno() to __wait_request()
  drm/i915: Convert trace functions from seqno to request
  drm/i915: Convert 'trace_irq' to use requests rather than seqnos
  drm/i915: Convert semaphores to handle requests not seqnos
  drm/i915: Convert 'ring_idle()' to use requests not seqnos
  drm/i915: Remove 'obj->ring'

 drivers/gpu/drm/i915/i915_debugfs.c        |   23 +--
 drivers/gpu/drm/i915/i915_drv.h            |   64 +++++--
 drivers/gpu/drm/i915/i915_gem.c            |  265 ++++++++++++++--------------
 drivers/gpu/drm/i915/i915_gem_context.c    |   12 +-
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |    8 +-
 drivers/gpu/drm/i915/i915_gem_gtt.h        |    4 +-
 drivers/gpu/drm/i915/i915_gem_tiling.c     |    2 +-
 drivers/gpu/drm/i915/i915_gpu_error.c      |   19 +-
 drivers/gpu/drm/i915/i915_irq.c            |   12 +-
 drivers/gpu/drm/i915/i915_trace.h          |   47 ++---
 drivers/gpu/drm/i915/intel_display.c       |   47 ++---
 drivers/gpu/drm/i915/intel_drv.h           |    4 +-
 drivers/gpu/drm/i915/intel_lrc.c           |   49 ++---
 drivers/gpu/drm/i915/intel_overlay.c       |   17 +-
 drivers/gpu/drm/i915/intel_ringbuffer.c    |   88 +++++----
 drivers/gpu/drm/i915/intel_ringbuffer.h    |   24 ++-
 16 files changed, 392 insertions(+), 293 deletions(-)

-- 
1.7.9.5

[RFC 01/21] Bug: missing i915_seqno_passed() call?

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

---
 drivers/gpu/drm/i915/i915_gem.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 2a5351d..8c68219 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2886,7 +2886,7 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
 	seqno = obj->last_read_seqno;
 	/* Optimization: Avoid semaphore sync when we are sure we already
 	 * waited for an object with higher seqno */
-	if (seqno <= from->semaphore.sync_seqno[idx])
+	if (seqno <= from->semaphore.sync_seqno[idx]) /* <--- broken?! needs to use i915_seqno_passed()??? */
 		return 0;
 
 	ret = i915_gem_check_olr(obj->ring, seqno);
-- 
1.7.9.5

[RFC 02/21] drm/i915: Remove redundant parameter to i915_gem_object_wait_rendering__tail()

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_gem.c |    7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 8c68219..aa2d882 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1281,8 +1281,7 @@ i915_wait_seqno(struct intel_engine_cs *ring, uint32_t seqno)
 }
 
 static int
-i915_gem_object_wait_rendering__tail(struct drm_i915_gem_object *obj,
-				     struct intel_engine_cs *ring)
+i915_gem_object_wait_rendering__tail(struct drm_i915_gem_object *obj)
 {
 	if (!obj->active)
 		return 0;
@@ -1319,7 +1318,7 @@ i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj,
 	if (ret)
 		return ret;
 
-	return i915_gem_object_wait_rendering__tail(obj, ring);
+	return i915_gem_object_wait_rendering__tail(obj);
 }
 
 /* A nonblocking variant of the above wait. This is a highly dangerous routine
@@ -1359,7 +1358,7 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
 	if (ret)
 		return ret;
 
-	return i915_gem_object_wait_rendering__tail(obj, ring);
+	return i915_gem_object_wait_rendering__tail(obj);
 }
 
 /**
-- 
1.7.9.5

[RFC 03/21] drm/i915: Ensure OLS & PLR are always in sync

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

The new seqno alloction code pre-allocates a 'lazy' request structure and then
tries to allocate the 'lazy' seqno. The seqno allocation can potential wrap
around zero and when doing so, tries to idle the ring by waiting for all
oustanding work to complete. With a scheduler in place, this can mean first
submitting extra work to the ring. However, at this point in time, the lazy
request is valid but the lazy seqno is not. Some existing code was getting
confused by this state and Bad Things would happen.

The safest solution is to still allocate the lazy request in advance (to avoid
having to roll back in an out of memory sitation) but to save the pointer in a
local variable rather than immediately updating the lazy pointer. Only after a
valid seqno has been acquired is the lazy request pointer actually updated.

This guarantees that both lazy values are either invalid or both valid. There
can no longer be an inconsistent state.

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/intel_lrc.c        |   42 ++++++++++++++++++++-----------
 drivers/gpu/drm/i915/intel_ringbuffer.c |   29 +++++++++++++++------
 2 files changed, 48 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index bafd38b..3ac2622 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -796,27 +796,39 @@ void intel_logical_ring_advance_and_submit(struct intel_ringbuffer *ringbuf)
 static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
 				    struct intel_context *ctx)
 {
-	if (ring->outstanding_lazy_seqno)
-		return 0;
+	struct drm_i915_gem_request *request;
+	int ret;
 
-	if (ring->preallocated_lazy_request == NULL) {
-		struct drm_i915_gem_request *request;
+	/* The aim is to replace seqno values with request structures. A step
+	 * along the way is to switch to using the PLR in preference to the
+	 * OLS. That requires the PLR to only be valid when the OLS is also
+	 * valid. I.e., the two must be kept in step. */
 
-		request = kmalloc(sizeof(*request), GFP_KERNEL);
-		if (request == NULL)
-			return -ENOMEM;
+	if (ring->outstanding_lazy_seqno) {
+		BUG_ON(ring->preallocated_lazy_request == NULL);
+		return 0;
+	}
+	BUG_ON(ring->preallocated_lazy_request != NULL);
 
-		/* Hold a reference to the context this request belongs to
-		 * (we will need it when the time comes to emit/retire the
-		 * request).
-		 */
-		request->ctx = ctx;
-		i915_gem_context_reference(request->ctx);
+	request = kmalloc(sizeof(*request), GFP_KERNEL);
+	if (request == NULL)
+		return -ENOMEM;
 
-		ring->preallocated_lazy_request = request;
+	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
+	if (ret) {
+		kfree(request);
+		return ret;
 	}
 
-	return i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
+	/* Hold a reference to the context this request belongs to
+	 * (we will need it when the time comes to emit/retire the
+	 * request).
+	 */
+	request->ctx = ctx;
+	i915_gem_context_reference(request->ctx);
+
+	ring->preallocated_lazy_request = request;
+	return 0;
 }
 
 static int logical_ring_wait_request(struct intel_ringbuffer *ringbuf,
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 25795f2..cceac67 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2000,20 +2000,33 @@ int intel_ring_idle(struct intel_engine_cs *ring)
 static int
 intel_ring_alloc_seqno(struct intel_engine_cs *ring)
 {
-	if (ring->outstanding_lazy_seqno)
+	int ret;
+	struct drm_i915_gem_request *request;
+
+	/* The aim is to replace seqno values with request structures. A step
+	 * along the way is to switch to using the PLR in preference to the
+	 * OLS. That requires the PLR to only be valid when the OLS is also
+	 * valid. I.e., the two must be kept in step. */
+
+	if (ring->outstanding_lazy_seqno) {
+		BUG_ON(ring->preallocated_lazy_request == NULL);
 		return 0;
+	}
 
-	if (ring->preallocated_lazy_request == NULL) {
-		struct drm_i915_gem_request *request;
+	BUG_ON(ring->preallocated_lazy_request != NULL);
 
-		request = kmalloc(sizeof(*request), GFP_KERNEL);
-		if (request == NULL)
-			return -ENOMEM;
+	request = kmalloc(sizeof(*request), GFP_KERNEL);
+	if (request == NULL)
+		return -ENOMEM;
 
-		ring->preallocated_lazy_request = request;
+	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
+	if (ret) {
+		kfree(request);
+		return ret;
 	}
 
-	return i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
+	ring->preallocated_lazy_request = request;
+	return 0;
 }
 
 static int __intel_ring_prepare(struct intel_engine_cs *ring,
-- 
1.7.9.5

[RFC 04/21] drm/i915: Add reference count to request structure

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_drv.h         |   16 ++++++++++++++++
 drivers/gpu/drm/i915/i915_gem.c         |   20 ++++++++++++++++----
 drivers/gpu/drm/i915/intel_lrc.c        |    2 ++
 drivers/gpu/drm/i915/intel_ringbuffer.c |    2 ++
 4 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e3ca8df..e1858e7 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1913,6 +1913,8 @@ void i915_gem_track_fb(struct drm_i915_gem_object *old,
  * an emission time with seqnos for tracking how far ahead of the GPU we are.
  */
 struct drm_i915_gem_request {
+	struct kref ref;
+
 	/** On Which ring this request was generated */
 	struct intel_engine_cs *ring;
 
@@ -1942,6 +1944,20 @@ struct drm_i915_gem_request {
 	struct list_head client_list;
 };
 
+void i915_gem_request_free(struct kref *req_ref);
+
+static inline void
+i915_gem_request_reference(struct drm_i915_gem_request *req)
+{
+	kref_get(&req->ref);
+}
+
+static inline void
+i915_gem_request_unreference(struct drm_i915_gem_request *req)
+{
+	kref_put(&req->ref, i915_gem_request_free);
+}
+
 struct drm_i915_file_private {
 	struct drm_i915_private *dev_priv;
 	struct drm_file *file;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index aa2d882..2555cd8 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2379,6 +2379,8 @@ int __i915_add_request(struct intel_engine_cs *ring,
 			return ret;
 	}
 
+	i915_gem_request_reference(request);
+
 	request->seqno = intel_ring_get_seqno(ring);
 	request->ring = ring;
 	request->head = request_start;
@@ -2495,12 +2497,22 @@ static void i915_set_reset_status(struct drm_i915_private *dev_priv,
 static void i915_gem_free_request(struct drm_i915_gem_request *request)
 {
 	list_del(&request->list);
-	i915_gem_request_remove_from_client(request);
 
-	if (request->ctx)
-		i915_gem_context_unreference(request->ctx);
+	i915_gem_request_unreference(request);
+}
+
+void i915_gem_request_free(struct kref *req_ref)
+{
+	struct drm_i915_gem_request *req = container_of(req_ref,
+						 typeof(*req), ref);
+
+	/*list_del(&req->list);*/
+	i915_gem_request_remove_from_client(req);
+
+	if (req->ctx)
+		i915_gem_context_unreference(req->ctx);
 
-	kfree(request);
+	kfree(req);
 }
 
 struct drm_i915_gem_request *
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 3ac2622..b5b6430 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -814,6 +814,8 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
 	if (request == NULL)
 		return -ENOMEM;
 
+	kref_init(&request->ref);
+
 	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
 	if (ret) {
 		kfree(request);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index cceac67..7350f78 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2019,6 +2019,8 @@ intel_ring_alloc_seqno(struct intel_engine_cs *ring)
 	if (request == NULL)
 		return -ENOMEM;
 
+	kref_init(&request->ref);
+
 	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
 	if (ret) {
 		kfree(request);
-- 
1.7.9.5

[RFC 05/21] drm/i915: Add helper functions to aid seqno -> request transition

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_drv.h         |   12 ++++++++++++
 drivers/gpu/drm/i915/intel_ringbuffer.h |    7 +++++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e1858e7..62c9f66 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1946,6 +1946,18 @@ struct drm_i915_gem_request {
 
 void i915_gem_request_free(struct kref *req_ref);
 
+static inline uint32_t
+i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
+{
+	return req ? req->seqno : 0;
+}
+
+static inline struct intel_engine_cs *
+i915_gem_request_get_ring(struct drm_i915_gem_request *req)
+{
+	return req ? req->ring : NULL;
+}
+
 static inline void
 i915_gem_request_reference(struct drm_i915_gem_request *req)
 {
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 96479c8..cc1b62f 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -435,6 +435,13 @@ static inline u32 intel_ring_get_seqno(struct intel_engine_cs *ring)
 	return ring->outstanding_lazy_seqno;
 }
 
+static inline struct drm_i915_gem_request *
+intel_ring_get_request(struct intel_engine_cs *ring)
+{
+	BUG_ON(ring->preallocated_lazy_request == NULL);
+	return ring->preallocated_lazy_request;
+}
+
 static inline void i915_trace_irq_get(struct intel_engine_cs *ring, u32 seqno)
 {
 	if (ring->trace_irq_seqno == 0 && ring->irq_get(ring))
-- 
1.7.9.5

[RFC 06/21] drm/i915: Replace last_[rwf]_seqno with last_[rwf]_req

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_debugfs.c        |    6 +--
 drivers/gpu/drm/i915/i915_drv.h            |    6 +--
 drivers/gpu/drm/i915/i915_gem.c            |   66 ++++++++++++++++------------
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |    6 +--
 drivers/gpu/drm/i915/i915_gem_gtt.h        |    4 +-
 drivers/gpu/drm/i915/i915_gem_tiling.c     |    2 +-
 drivers/gpu/drm/i915/i915_gpu_error.c      |    4 +-
 drivers/gpu/drm/i915/intel_display.c       |   10 ++---
 drivers/gpu/drm/i915/intel_ringbuffer.h    |    2 +-
 9 files changed, 58 insertions(+), 48 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 063b448..726a8f0 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -133,9 +133,9 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj)
 		   obj->base.size / 1024,
 		   obj->base.read_domains,
 		   obj->base.write_domain,
-		   obj->last_read_seqno,
-		   obj->last_write_seqno,
-		   obj->last_fenced_seqno,
+		   i915_gem_request_get_seqno(obj->last_read_req),
+		   i915_gem_request_get_seqno(obj->last_write_req),
+		   i915_gem_request_get_seqno(obj->last_fenced_req),
 		   i915_cache_level_str(to_i915(obj->base.dev), obj->cache_level),
 		   obj->dirty ? " dirty" : "",
 		   obj->madv == I915_MADV_DONTNEED ? " purgeable" : "");
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 62c9f66..1401266 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1862,10 +1862,10 @@ struct drm_i915_gem_object {
 	struct intel_engine_cs *ring;
 
 	/** Breadcrumb of last rendering to the buffer. */
-	uint32_t last_read_seqno;
-	uint32_t last_write_seqno;
+	struct drm_i915_gem_request *last_read_req;
+	struct drm_i915_gem_request *last_write_req;
 	/** Breadcrumb of last fenced GPU access to the buffer. */
-	uint32_t last_fenced_seqno;
+	struct drm_i915_gem_request *last_fenced_req;
 
 	/** Current tiling stride for the object, if it's tiled. */
 	uint32_t stride;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 2555cd8..2c33a83 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1289,11 +1289,11 @@ i915_gem_object_wait_rendering__tail(struct drm_i915_gem_object *obj)
 	/* Manually manage the write flush as we may have not yet
 	 * retired the buffer.
 	 *
-	 * Note that the last_write_seqno is always the earlier of
-	 * the two (read/write) seqno, so if we haved successfully waited,
+	 * Note that the last_write_req is always the earlier of
+	 * the two (read/write) requests, so if we haved successfully waited,
 	 * we know we have passed the last write.
 	 */
-	obj->last_write_seqno = 0;
+	obj->last_write_req = NULL;
 
 	return 0;
 }
@@ -1306,14 +1306,18 @@ static __must_check int
 i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj,
 			       bool readonly)
 {
+	struct drm_i915_gem_request *req;
 	struct intel_engine_cs *ring = obj->ring;
 	u32 seqno;
 	int ret;
 
-	seqno = readonly ? obj->last_write_seqno : obj->last_read_seqno;
-	if (seqno == 0)
+	req = readonly ? obj->last_write_req : obj->last_read_req;
+	if (!req)
 		return 0;
 
+	seqno = i915_gem_request_get_seqno(req);
+	BUG_ON(seqno == 0);
+
 	ret = i915_wait_seqno(ring, seqno);
 	if (ret)
 		return ret;
@@ -1329,6 +1333,7 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
 					    struct drm_i915_file_private *file_priv,
 					    bool readonly)
 {
+	struct drm_i915_gem_request *req;
 	struct drm_device *dev = obj->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *ring = obj->ring;
@@ -1339,10 +1344,13 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
 	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
 	BUG_ON(!dev_priv->mm.interruptible);
 
-	seqno = readonly ? obj->last_write_seqno : obj->last_read_seqno;
-	if (seqno == 0)
+	req = readonly ? obj->last_write_req : obj->last_read_req;
+	if (!req)
 		return 0;
 
+	seqno = i915_gem_request_get_seqno(req);
+	BUG_ON(seqno == 0);
+
 	ret = i915_gem_check_wedge(&dev_priv->gpu_error, true);
 	if (ret)
 		return ret;
@@ -2180,12 +2188,12 @@ static void
 i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
 			       struct intel_engine_cs *ring)
 {
-	u32 seqno = intel_ring_get_seqno(ring);
+	struct drm_i915_gem_request *req = intel_ring_get_request(ring);
 
 	BUG_ON(ring == NULL);
-	if (obj->ring != ring && obj->last_write_seqno) {
-		/* Keep the seqno relative to the current ring */
-		obj->last_write_seqno = seqno;
+	if (obj->ring != ring && obj->last_write_req) {
+		/* Keep the request relative to the current ring */
+		obj->last_write_req = req;
 	}
 	obj->ring = ring;
 
@@ -2197,7 +2205,7 @@ i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
 
 	list_move_tail(&obj->ring_list, &ring->active_list);
 
-	obj->last_read_seqno = seqno;
+	obj->last_read_req = req;
 }
 
 void i915_vma_move_to_active(struct i915_vma *vma,
@@ -2228,11 +2236,11 @@ i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
 	list_del_init(&obj->ring_list);
 	obj->ring = NULL;
 
-	obj->last_read_seqno = 0;
-	obj->last_write_seqno = 0;
+	obj->last_read_req = NULL;
+	obj->last_write_req = NULL;
 	obj->base.write_domain = 0;
 
-	obj->last_fenced_seqno = 0;
+	obj->last_fenced_req = NULL;
 
 	obj->active = 0;
 	drm_gem_object_unreference(&obj->base);
@@ -2249,7 +2257,7 @@ i915_gem_object_retire(struct drm_i915_gem_object *obj)
 		return;
 
 	if (i915_seqno_passed(ring->get_seqno(ring, true),
-			      obj->last_read_seqno))
+			      i915_gem_request_get_seqno(obj->last_read_req)))
 		i915_gem_object_move_to_inactive(obj);
 }
 
@@ -2669,7 +2677,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
 				      struct drm_i915_gem_object,
 				      ring_list);
 
-		if (!i915_seqno_passed(seqno, obj->last_read_seqno))
+		if (!i915_seqno_passed(seqno, i915_gem_request_get_seqno(obj->last_read_req)))
 			break;
 
 		i915_gem_object_move_to_inactive(obj);
@@ -2779,7 +2787,7 @@ i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
 	int ret;
 
 	if (obj->active) {
-		ret = i915_gem_check_olr(obj->ring, obj->last_read_seqno);
+		ret = i915_gem_check_olr(obj->ring, i915_gem_request_get_seqno(obj->last_read_req));
 		if (ret)
 			return ret;
 
@@ -2838,13 +2846,14 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 		goto out;
 
 	if (obj->active) {
-		seqno = obj->last_read_seqno;
+		if (!obj->last_read_req)
+			goto out;
+
+		seqno = i915_gem_request_get_seqno(obj->last_read_req);
+		BUG_ON(seqno == 0);
 		ring = obj->ring;
 	}
 
-	if (seqno == 0)
-		 goto out;
-
 	/* Do this after OLR check to make sure we make forward progress polling
 	 * on this IOCTL with a timeout <=0 (like busy ioctl)
 	 */
@@ -2894,7 +2903,7 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
 
 	idx = intel_ring_sync_index(from, to);
 
-	seqno = obj->last_read_seqno;
+	seqno = i915_gem_request_get_seqno(obj->last_read_req);
 	/* Optimization: Avoid semaphore sync when we are sure we already
 	 * waited for an object with higher seqno */
 	if (seqno <= from->semaphore.sync_seqno[idx]) /* <--- broken?! needs to use i915_seqno_passed()??? */
@@ -2907,11 +2916,12 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
 	trace_i915_gem_ring_sync_to(from, to, seqno);
 	ret = to->semaphore.sync_to(to, from, seqno);
 	if (!ret)
-		/* We use last_read_seqno because sync_to()
+		/* We use last_read_req because sync_to()
 		 * might have just caused seqno wrap under
 		 * the radar.
 		 */
-		from->semaphore.sync_seqno[idx] = obj->last_read_seqno;
+		from->semaphore.sync_seqno[idx] =
+				i915_gem_request_get_seqno(obj->last_read_req);
 
 	return ret;
 }
@@ -3224,12 +3234,12 @@ static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
 static int
 i915_gem_object_wait_fence(struct drm_i915_gem_object *obj)
 {
-	if (obj->last_fenced_seqno) {
-		int ret = i915_wait_seqno(obj->ring, obj->last_fenced_seqno);
+	if (obj->last_fenced_req) {
+		int ret = i915_wait_seqno(obj->ring, i915_gem_request_get_seqno(obj->last_fenced_req));
 		if (ret)
 			return ret;
 
-		obj->last_fenced_seqno = 0;
+		obj->last_fenced_req = NULL;
 	}
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 1a0611b..4250211 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -946,7 +946,7 @@ void
 i915_gem_execbuffer_move_to_active(struct list_head *vmas,
 				   struct intel_engine_cs *ring)
 {
-	u32 seqno = intel_ring_get_seqno(ring);
+	struct drm_i915_gem_request *req = intel_ring_get_request(ring);
 	struct i915_vma *vma;
 
 	list_for_each_entry(vma, vmas, exec_list) {
@@ -963,7 +963,7 @@ i915_gem_execbuffer_move_to_active(struct list_head *vmas,
 		i915_vma_move_to_active(vma, ring);
 		if (obj->base.write_domain) {
 			obj->dirty = 1;
-			obj->last_write_seqno = seqno;
+			obj->last_write_req = req;
 
 			intel_fb_obj_invalidate(obj, ring);
 
@@ -971,7 +971,7 @@ i915_gem_execbuffer_move_to_active(struct list_head *vmas,
 			obj->base.write_domain &= ~I915_GEM_GPU_DOMAINS;
 		}
 		if (entry->flags & EXEC_OBJECT_NEEDS_FENCE) {
-			obj->last_fenced_seqno = seqno;
+			obj->last_fenced_req = req;
 			if (entry->flags & __EXEC_OBJECT_HAS_FENCE) {
 				struct drm_i915_private *dev_priv = to_i915(ring->dev);
 				list_move_tail(&dev_priv->fence_regs[obj->fence_reg].lru_list,
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index d5c14af..8a220c0 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -178,7 +178,7 @@ struct i915_address_space {
 	 * List of objects currently involved in rendering.
 	 *
 	 * Includes buffers having the contents of their GPU caches
-	 * flushed, not necessarily primitives.  last_rendering_seqno
+	 * flushed, not necessarily primitives.  last_rendering_req
 	 * represents when the rendering involved will be completed.
 	 *
 	 * A reference is held on the buffer while on this list.
@@ -189,7 +189,7 @@ struct i915_address_space {
 	 * LRU list of objects which are not in the ringbuffer and
 	 * are ready to unbind, but are still in the GTT.
 	 *
-	 * last_rendering_seqno is 0 while an object is in this list.
+	 * last_rendering_req is NULL while an object is in this list.
 	 *
 	 * A reference is not held on the buffer while on this list,
 	 * as merely being GTT-bound shouldn't prevent its being
diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
index 2cefb59..fa5fc8c 100644
--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -383,7 +383,7 @@ i915_gem_set_tiling(struct drm_device *dev, void *data,
 
 		if (ret == 0) {
 			obj->fence_dirty =
-				obj->last_fenced_seqno ||
+				obj->last_fenced_req ||
 				obj->fence_reg != I915_FENCE_REG_NONE;
 
 			obj->tiling_mode = args->tiling_mode;
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 2c87a79..1b58390 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -666,8 +666,8 @@ static void capture_bo(struct drm_i915_error_buffer *err,
 
 	err->size = obj->base.size;
 	err->name = obj->base.name;
-	err->rseqno = obj->last_read_seqno;
-	err->wseqno = obj->last_write_seqno;
+	err->rseqno = i915_gem_request_get_seqno(obj->last_read_req);
+	err->wseqno = i915_gem_request_get_seqno(obj->last_write_req);
 	err->gtt_offset = vma->node.start;
 	err->read_domains = obj->base.read_domains;
 	err->write_domain = obj->base.write_domain;
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index b78f00a..5aae3d1e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9766,16 +9766,16 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
 
 	lockdep_assert_held(&obj->base.dev->struct_mutex);
 
-	if (!obj->last_write_seqno)
+	if (!obj->last_write_req)
 		return 0;
 
 	ring = obj->ring;
 
 	if (i915_seqno_passed(ring->get_seqno(ring, true),
-			      obj->last_write_seqno))
+			      i915_gem_request_get_seqno(obj->last_write_req)))
 		return 0;
 
-	ret = i915_gem_check_olr(ring, obj->last_write_seqno);
+	ret = i915_gem_check_olr(ring, i915_gem_request_get_seqno(obj->last_write_req));
 	if (ret)
 		return ret;
 
@@ -9838,7 +9838,7 @@ static int intel_queue_mmio_flip(struct drm_device *dev,
 	}
 
 	spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
-	intel_crtc->mmio_flip.seqno = obj->last_write_seqno;
+	intel_crtc->mmio_flip.seqno = i915_gem_request_get_seqno(obj->last_write_req);
 	intel_crtc->mmio_flip.ring_id = obj->ring->id;
 	spin_unlock_irqrestore(&dev_priv->mmio_flip_lock, irq_flags);
 
@@ -10045,7 +10045,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 		if (ret)
 			goto cleanup_unpin;
 
-		work->flip_queued_seqno = obj->last_write_seqno;
+		work->flip_queued_seqno = i915_gem_request_get_seqno(obj->last_write_req);
 		work->flip_queued_ring = obj->ring;
 	} else {
 		ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, ring,
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index cc1b62f..d98b964 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -249,7 +249,7 @@ struct  intel_engine_cs {
 	 * ringbuffer.
 	 *
 	 * Includes buffers having the contents of their GPU caches
-	 * flushed, not necessarily primitives.  last_rendering_seqno
+	 * flushed, not necessarily primitives.  last_rendering_req
 	 * represents when the rendering involved will be completed.
 	 *
 	 * A reference is held on the buffer while on this list.
-- 
1.7.9.5

[RFC 07/21] drm/i915: Ensure requests stick around during waits

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_gem.c |   25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 2c33a83..53b48ad 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1360,9 +1360,11 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
 		return ret;
 
 	reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter);
+	i915_gem_request_reference(req);
 	mutex_unlock(&dev->struct_mutex);
 	ret = __wait_seqno(ring, seqno, reset_counter, true, NULL, file_priv);
 	mutex_lock(&dev->struct_mutex);
+	i915_gem_request_unreference(req);
 	if (ret)
 		return ret;
 
@@ -2825,6 +2827,7 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct drm_i915_gem_wait *args = data;
 	struct drm_i915_gem_object *obj;
+	struct drm_i915_gem_request *req;
 	struct intel_engine_cs *ring = NULL;
 	unsigned reset_counter;
 	u32 seqno = 0;
@@ -2845,14 +2848,13 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 	if (ret)
 		goto out;
 
-	if (obj->active) {
-		if (!obj->last_read_req)
-			goto out;
+	if (!obj->active || !obj->last_read_req)
+		goto out;
 
-		seqno = i915_gem_request_get_seqno(obj->last_read_req);
-		BUG_ON(seqno == 0);
-		ring = obj->ring;
-	}
+	req = obj->last_read_req;
+	seqno = i915_gem_request_get_seqno(req);
+	BUG_ON(seqno == 0);
+	ring = obj->ring;
 
 	/* Do this after OLR check to make sure we make forward progress polling
 	 * on this IOCTL with a timeout <=0 (like busy ioctl)
@@ -2864,10 +2866,15 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 
 	drm_gem_object_unreference(&obj->base);
 	reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter);
+	i915_gem_request_reference(req);
 	mutex_unlock(&dev->struct_mutex);
 
-	return __wait_seqno(ring, seqno, reset_counter, true, &args->timeout_ns,
-			    file->driver_priv);
+	ret = __wait_seqno(ring, seqno, reset_counter, true, &args->timeout_ns,
+			   file->driver_priv);
+	mutex_lock(&dev->struct_mutex);
+	i915_gem_request_unreference(req);
+	mutex_unlock(&dev->struct_mutex);
+	return ret;
 
 out:
 	drm_gem_object_unreference(&obj->base);
-- 
1.7.9.5

[RFC 08/21] drm/i915: Remove 'outstanding_lazy_seqno'

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_gem.c            |   13 +++-----
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |    2 +-
 drivers/gpu/drm/i915/intel_display.c       |    2 +-
 drivers/gpu/drm/i915/intel_lrc.c           |   20 ++++--------
 drivers/gpu/drm/i915/intel_ringbuffer.c    |   48 +++++++++++++++-------------
 drivers/gpu/drm/i915/intel_ringbuffer.h    |   13 ++------
 6 files changed, 41 insertions(+), 57 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 53b48ad..0d0eb26 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1108,7 +1108,7 @@ i915_gem_check_olr(struct intel_engine_cs *ring, u32 seqno)
 	BUG_ON(!mutex_is_locked(&ring->dev->struct_mutex));
 
 	ret = 0;
-	if (seqno == ring->outstanding_lazy_seqno)
+	if (seqno == i915_gem_request_get_seqno(ring->outstanding_lazy_request))
 		ret = i915_add_request(ring, NULL);
 
 	return ret;
@@ -2344,7 +2344,7 @@ int __i915_add_request(struct intel_engine_cs *ring,
 	u32 request_ring_position, request_start;
 	int ret;
 
-	request = ring->preallocated_lazy_request;
+	request = ring->outstanding_lazy_request;
 	if (WARN_ON(request == NULL))
 		return -ENOMEM;
 
@@ -2391,7 +2391,6 @@ int __i915_add_request(struct intel_engine_cs *ring,
 
 	i915_gem_request_reference(request);
 
-	request->seqno = intel_ring_get_seqno(ring);
 	request->ring = ring;
 	request->head = request_start;
 	request->tail = request_ring_position;
@@ -2428,8 +2427,7 @@ int __i915_add_request(struct intel_engine_cs *ring,
 	}
 
 	trace_i915_gem_request_add(ring, request->seqno);
-	ring->outstanding_lazy_seqno = 0;
-	ring->preallocated_lazy_request = NULL;
+	ring->outstanding_lazy_request = NULL;
 
 	if (!dev_priv->ums.mm_suspended) {
 		i915_queue_hangcheck(ring->dev);
@@ -2605,9 +2603,8 @@ static void i915_gem_reset_ring_cleanup(struct drm_i915_private *dev_priv,
 	}
 
 	/* These may not have been flush before the reset, do so now */
-	kfree(ring->preallocated_lazy_request);
-	ring->preallocated_lazy_request = NULL;
-	ring->outstanding_lazy_seqno = 0;
+	kfree(ring->outstanding_lazy_request);
+	ring->outstanding_lazy_request = NULL;
 }
 
 void i915_gem_restore_fences(struct drm_device *dev)
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 4250211..e0fdfae 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1170,7 +1170,7 @@ i915_gem_ringbuffer_submission(struct drm_device *dev, struct drm_file *file,
 			return ret;
 	}
 
-	trace_i915_gem_ring_dispatch(ring, intel_ring_get_seqno(ring), flags);
+	trace_i915_gem_ring_dispatch(ring, i915_gem_request_get_seqno(intel_ring_get_request(ring)), flags);
 
 	i915_gem_execbuffer_move_to_active(vmas, ring);
 	i915_gem_execbuffer_retire_commands(dev, file, ring, batch_obj);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5aae3d1e..6da18c5 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -10053,7 +10053,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 		if (ret)
 			goto cleanup_unpin;
 
-		work->flip_queued_seqno = intel_ring_get_seqno(ring);
+		work->flip_queued_seqno = i915_gem_request_get_seqno(intel_ring_get_request(ring));
 		work->flip_queued_ring = ring;
 	}
 
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index b5b6430..7005745 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -799,16 +799,8 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
 	struct drm_i915_gem_request *request;
 	int ret;
 
-	/* The aim is to replace seqno values with request structures. A step
-	 * along the way is to switch to using the PLR in preference to the
-	 * OLS. That requires the PLR to only be valid when the OLS is also
-	 * valid. I.e., the two must be kept in step. */
-
-	if (ring->outstanding_lazy_seqno) {
-		BUG_ON(ring->preallocated_lazy_request == NULL);
+	if (ring->outstanding_lazy_request)
 		return 0;
-	}
-	BUG_ON(ring->preallocated_lazy_request != NULL);
 
 	request = kmalloc(sizeof(*request), GFP_KERNEL);
 	if (request == NULL)
@@ -816,7 +808,7 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
 
 	kref_init(&request->ref);
 
-	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
+	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
 		kfree(request);
 		return ret;
@@ -829,7 +821,7 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
 	request->ctx = ctx;
 	i915_gem_context_reference(request->ctx);
 
-	ring->preallocated_lazy_request = request;
+	ring->outstanding_lazy_request = request;
 	return 0;
 }
 
@@ -1212,7 +1204,8 @@ static int gen8_emit_request(struct intel_ringbuffer *ringbuf)
 				(ring->status_page.gfx_addr +
 				(I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT)));
 	intel_logical_ring_emit(ringbuf, 0);
-	intel_logical_ring_emit(ringbuf, ring->outstanding_lazy_seqno);
+	intel_logical_ring_emit(ringbuf,
+		i915_gem_request_get_seqno(ring->outstanding_lazy_request));
 	intel_logical_ring_emit(ringbuf, MI_USER_INTERRUPT);
 	intel_logical_ring_emit(ringbuf, MI_NOOP);
 	intel_logical_ring_advance_and_submit(ringbuf);
@@ -1235,8 +1228,7 @@ void intel_logical_ring_cleanup(struct intel_engine_cs *ring)
 
 	intel_logical_ring_stop(ring);
 	WARN_ON((I915_READ_MODE(ring) & MODE_IDLE) == 0);
-	ring->preallocated_lazy_request = NULL;
-	ring->outstanding_lazy_seqno = 0;
+	ring->outstanding_lazy_request = NULL;
 
 	if (ring->cleanup)
 		ring->cleanup(ring);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 7350f78..dd59691 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -895,17 +895,20 @@ static int gen8_rcs_signal(struct intel_engine_cs *signaller,
 		return ret;
 
 	for_each_ring(waiter, dev_priv, i) {
+		u32 seqno;
 		u64 gtt_offset = signaller->semaphore.signal_ggtt[i];
 		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
 			continue;
 
+		seqno = i915_gem_request_get_seqno(
+					   signaller->outstanding_lazy_request);
 		intel_ring_emit(signaller, GFX_OP_PIPE_CONTROL(6));
 		intel_ring_emit(signaller, PIPE_CONTROL_GLOBAL_GTT_IVB |
 					   PIPE_CONTROL_QW_WRITE |
 					   PIPE_CONTROL_FLUSH_ENABLE);
 		intel_ring_emit(signaller, lower_32_bits(gtt_offset));
 		intel_ring_emit(signaller, upper_32_bits(gtt_offset));
-		intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
+		intel_ring_emit(signaller, seqno);
 		intel_ring_emit(signaller, 0);
 		intel_ring_emit(signaller, MI_SEMAPHORE_SIGNAL |
 					   MI_SEMAPHORE_TARGET(waiter->id));
@@ -933,16 +936,19 @@ static int gen8_xcs_signal(struct intel_engine_cs *signaller,
 		return ret;
 
 	for_each_ring(waiter, dev_priv, i) {
+		u32 seqno;
 		u64 gtt_offset = signaller->semaphore.signal_ggtt[i];
 		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
 			continue;
 
+		seqno = i915_gem_request_get_seqno(
+					   signaller->outstanding_lazy_request);
 		intel_ring_emit(signaller, (MI_FLUSH_DW + 1) |
 					   MI_FLUSH_DW_OP_STOREDW);
 		intel_ring_emit(signaller, lower_32_bits(gtt_offset) |
 					   MI_FLUSH_DW_USE_GTT);
 		intel_ring_emit(signaller, upper_32_bits(gtt_offset));
-		intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
+		intel_ring_emit(signaller, seqno);
 		intel_ring_emit(signaller, MI_SEMAPHORE_SIGNAL |
 					   MI_SEMAPHORE_TARGET(waiter->id));
 		intel_ring_emit(signaller, 0);
@@ -971,9 +977,11 @@ static int gen6_signal(struct intel_engine_cs *signaller,
 	for_each_ring(useless, dev_priv, i) {
 		u32 mbox_reg = signaller->semaphore.mbox.signal[i];
 		if (mbox_reg != GEN6_NOSYNC) {
+			u32 seqno = i915_gem_request_get_seqno(
+					   signaller->outstanding_lazy_request);
 			intel_ring_emit(signaller, MI_LOAD_REGISTER_IMM(1));
 			intel_ring_emit(signaller, mbox_reg);
-			intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
+			intel_ring_emit(signaller, seqno);
 		}
 	}
 
@@ -1008,7 +1016,8 @@ gen6_add_request(struct intel_engine_cs *ring)
 
 	intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
 	intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
-	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
+	intel_ring_emit(ring,
+		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
 	intel_ring_emit(ring, MI_USER_INTERRUPT);
 	__intel_ring_advance(ring);
 
@@ -1126,7 +1135,8 @@ pc_render_add_request(struct intel_engine_cs *ring)
 			PIPE_CONTROL_WRITE_FLUSH |
 			PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE);
 	intel_ring_emit(ring, ring->scratch.gtt_offset | PIPE_CONTROL_GLOBAL_GTT);
-	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
+	intel_ring_emit(ring,
+		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
 	intel_ring_emit(ring, 0);
 	PIPE_CONTROL_FLUSH(ring, scratch_addr);
 	scratch_addr += 2 * CACHELINE_BYTES; /* write to separate cachelines */
@@ -1145,7 +1155,8 @@ pc_render_add_request(struct intel_engine_cs *ring)
 			PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE |
 			PIPE_CONTROL_NOTIFY);
 	intel_ring_emit(ring, ring->scratch.gtt_offset | PIPE_CONTROL_GLOBAL_GTT);
-	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
+	intel_ring_emit(ring,
+		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
 	intel_ring_emit(ring, 0);
 	__intel_ring_advance(ring);
 
@@ -1385,7 +1396,8 @@ i9xx_add_request(struct intel_engine_cs *ring)
 
 	intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
 	intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
-	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
+	intel_ring_emit(ring,
+		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
 	intel_ring_emit(ring, MI_USER_INTERRUPT);
 	__intel_ring_advance(ring);
 
@@ -1839,8 +1851,7 @@ void intel_cleanup_ring_buffer(struct intel_engine_cs *ring)
 	WARN_ON(!IS_GEN2(ring->dev) && (I915_READ_MODE(ring) & MODE_IDLE) == 0);
 
 	intel_destroy_ringbuffer_obj(ringbuf);
-	ring->preallocated_lazy_request = NULL;
-	ring->outstanding_lazy_seqno = 0;
+	ring->outstanding_lazy_request = NULL;
 
 	if (ring->cleanup)
 		ring->cleanup(ring);
@@ -1980,7 +1991,7 @@ int intel_ring_idle(struct intel_engine_cs *ring)
 	int ret;
 
 	/* We need to add any requests required to flush the objects and ring */
-	if (ring->outstanding_lazy_seqno) {
+	if (ring->outstanding_lazy_request) {
 		ret = i915_add_request(ring, NULL);
 		if (ret)
 			return ret;
@@ -2003,17 +2014,8 @@ intel_ring_alloc_seqno(struct intel_engine_cs *ring)
 	int ret;
 	struct drm_i915_gem_request *request;
 
-	/* The aim is to replace seqno values with request structures. A step
-	 * along the way is to switch to using the PLR in preference to the
-	 * OLS. That requires the PLR to only be valid when the OLS is also
-	 * valid. I.e., the two must be kept in step. */
-
-	if (ring->outstanding_lazy_seqno) {
-		BUG_ON(ring->preallocated_lazy_request == NULL);
+	if (ring->outstanding_lazy_request)
 		return 0;
-	}
-
-	BUG_ON(ring->preallocated_lazy_request != NULL);
 
 	request = kmalloc(sizeof(*request), GFP_KERNEL);
 	if (request == NULL)
@@ -2021,13 +2023,13 @@ intel_ring_alloc_seqno(struct intel_engine_cs *ring)
 
 	kref_init(&request->ref);
 
-	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
+	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
 		kfree(request);
 		return ret;
 	}
 
-	ring->preallocated_lazy_request = request;
+	ring->outstanding_lazy_request = request;
 	return 0;
 }
 
@@ -2103,7 +2105,7 @@ void intel_ring_init_seqno(struct intel_engine_cs *ring, u32 seqno)
 	struct drm_device *dev = ring->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	BUG_ON(ring->outstanding_lazy_seqno);
+	BUG_ON(ring->outstanding_lazy_request);
 
 	if (INTEL_INFO(dev)->gen == 6 || INTEL_INFO(dev)->gen == 7) {
 		I915_WRITE(RING_SYNC_0(ring->mmio_base), 0);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index d98b964..98b219d 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -265,8 +265,7 @@ struct  intel_engine_cs {
 	/**
 	 * Do we have some not yet emitted requests outstanding?
 	 */
-	struct drm_i915_gem_request *preallocated_lazy_request;
-	u32 outstanding_lazy_seqno;
+	struct drm_i915_gem_request *outstanding_lazy_request;
 	bool gpu_caches_dirty;
 	bool fbc_dirty;
 
@@ -429,17 +428,11 @@ static inline u32 intel_ring_get_tail(struct intel_ringbuffer *ringbuf)
 	return ringbuf->tail;
 }
 
-static inline u32 intel_ring_get_seqno(struct intel_engine_cs *ring)
-{
-	BUG_ON(ring->outstanding_lazy_seqno == 0);
-	return ring->outstanding_lazy_seqno;
-}
-
 static inline struct drm_i915_gem_request *
 intel_ring_get_request(struct intel_engine_cs *ring)
 {
-	BUG_ON(ring->preallocated_lazy_request == NULL);
-	return ring->preallocated_lazy_request;
+	BUG_ON(ring->outstanding_lazy_request == NULL);
+	return ring->outstanding_lazy_request;
 }
 
 static inline void i915_trace_irq_get(struct intel_engine_cs *ring, u32 seqno)
-- 
1.7.9.5

[RFC 09/21] drm/i915: Make 'i915_gem_check_olr' actually check by request not seqno

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_drv.h      |   17 ++++++++++++++++-
 drivers/gpu/drm/i915/i915_gem.c      |   25 ++++++++++---------------
 drivers/gpu/drm/i915/intel_display.c |    2 +-
 3 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 1401266..9504206 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2483,7 +2483,7 @@ bool i915_gem_retire_requests(struct drm_device *dev);
 void i915_gem_retire_requests_ring(struct intel_engine_cs *ring);
 int __must_check i915_gem_check_wedge(struct i915_gpu_error *error,
 				      bool interruptible);
-int __must_check i915_gem_check_olr(struct intel_engine_cs *ring, u32 seqno);
+int __must_check i915_gem_check_olr(struct drm_i915_gem_request *req);
 
 static inline bool i915_reset_in_progress(struct i915_gpu_error *error)
 {
@@ -3020,4 +3020,19 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 	}
 }
 
+/************************* Deprecated *************************/
+static inline int __must_check i915_gem_check_ols(struct intel_engine_cs *ring, u32 seqno)
+{
+	int ret;
+
+	BUG_ON(!mutex_is_locked(&ring->dev->struct_mutex));
+
+	ret = 0;
+	if (seqno == i915_gem_request_get_seqno(ring->outstanding_lazy_request))
+		ret = i915_add_request(ring, NULL);
+
+	return ret;
+}
+/************************* Deprecated *************************/
+
 #endif
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 0d0eb26..2c7deca 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1097,19 +1097,18 @@ i915_gem_check_wedge(struct i915_gpu_error *error,
 }
 
 /*
- * Compare seqno against outstanding lazy request. Emit a request if they are
- * equal.
+ * Compare arbitrary request against outstanding lazy request. Emit on match.
  */
 int
-i915_gem_check_olr(struct intel_engine_cs *ring, u32 seqno)
+i915_gem_check_olr(struct drm_i915_gem_request *req)
 {
 	int ret;
 
-	BUG_ON(!mutex_is_locked(&ring->dev->struct_mutex));
+	BUG_ON(!mutex_is_locked(&req->ring->dev->struct_mutex));
 
 	ret = 0;
-	if (seqno == i915_gem_request_get_seqno(ring->outstanding_lazy_request))
-		ret = i915_add_request(ring, NULL);
+	if (req == req->ring->outstanding_lazy_request)
+		ret = i915_add_request(req->ring, NULL);
 
 	return ret;
 }
@@ -1271,7 +1270,7 @@ i915_wait_seqno(struct intel_engine_cs *ring, uint32_t seqno)
 	if (ret)
 		return ret;
 
-	ret = i915_gem_check_olr(ring, seqno);
+	ret = i915_gem_check_ols(ring, seqno);
 	if (ret)
 		return ret;
 
@@ -1338,7 +1337,6 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *ring = obj->ring;
 	unsigned reset_counter;
-	u32 seqno;
 	int ret;
 
 	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
@@ -1348,21 +1346,18 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
 	if (!req)
 		return 0;
 
-	seqno = i915_gem_request_get_seqno(req);
-	BUG_ON(seqno == 0);
-
 	ret = i915_gem_check_wedge(&dev_priv->gpu_error, true);
 	if (ret)
 		return ret;
 
-	ret = i915_gem_check_olr(ring, seqno);
+	ret = i915_gem_check_olr(req);
 	if (ret)
 		return ret;
 
 	reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter);
 	i915_gem_request_reference(req);
 	mutex_unlock(&dev->struct_mutex);
-	ret = __wait_seqno(ring, seqno, reset_counter, true, NULL, file_priv);
+	ret = __wait_seqno(ring, i915_gem_request_get_seqno(req), reset_counter, true, NULL, file_priv);
 	mutex_lock(&dev->struct_mutex);
 	i915_gem_request_unreference(req);
 	if (ret)
@@ -2786,7 +2781,7 @@ i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
 	int ret;
 
 	if (obj->active) {
-		ret = i915_gem_check_olr(obj->ring, i915_gem_request_get_seqno(obj->last_read_req));
+		ret = i915_gem_check_olr(obj->last_read_req);
 		if (ret)
 			return ret;
 
@@ -2913,7 +2908,7 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
 	if (seqno <= from->semaphore.sync_seqno[idx]) /* <--- broken?! needs to use i915_seqno_passed()??? */
 		return 0;
 
-	ret = i915_gem_check_olr(obj->ring, seqno);
+	ret = i915_gem_check_olr(obj->last_read_req);
 	if (ret)
 		return ret;
 
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 6da18c5..2af421e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9775,7 +9775,7 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
 			      i915_gem_request_get_seqno(obj->last_write_req)))
 		return 0;
 
-	ret = i915_gem_check_olr(ring, i915_gem_request_get_seqno(obj->last_write_req));
+	ret = i915_gem_check_olr(obj->last_write_req);
 	if (ret)
 		return ret;
 
-- 
1.7.9.5

[RFC 10/21] drm/i915: Convert 'last_flip_req' to be a request not a seqno

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/intel_overlay.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
index dc2f4f2..ccd5732 100644
--- a/drivers/gpu/drm/i915/intel_overlay.c
+++ b/drivers/gpu/drm/i915/intel_overlay.c
@@ -182,7 +182,7 @@ struct intel_overlay {
 	u32 flip_addr;
 	struct drm_i915_gem_object *reg_bo;
 	/* flip handling */
-	uint32_t last_flip_req;
+	struct drm_i915_gem_request *last_flip_req;
 	void (*flip_tail)(struct intel_overlay *);
 };
 
@@ -217,17 +217,17 @@ static int intel_overlay_do_wait_request(struct intel_overlay *overlay,
 	int ret;
 
 	BUG_ON(overlay->last_flip_req);
-	ret = i915_add_request(ring, &overlay->last_flip_req);
+	ret = i915_add_request(ring, &overlay->last_flip_req->seqno);
 	if (ret)
 		return ret;
 
 	overlay->flip_tail = tail;
-	ret = i915_wait_seqno(ring, overlay->last_flip_req);
+	ret = i915_wait_seqno(ring, i915_gem_request_get_seqno(overlay->last_flip_req));
 	if (ret)
 		return ret;
 	i915_gem_retire_requests(dev);
 
-	overlay->last_flip_req = 0;
+	overlay->last_flip_req = NULL;
 	return 0;
 }
 
@@ -286,7 +286,7 @@ static int intel_overlay_continue(struct intel_overlay *overlay,
 	intel_ring_emit(ring, flip_addr);
 	intel_ring_advance(ring);
 
-	return i915_add_request(ring, &overlay->last_flip_req);
+	return i915_add_request(ring, &overlay->last_flip_req->seqno);
 }
 
 static void intel_overlay_release_old_vid_tail(struct intel_overlay *overlay)
@@ -366,10 +366,10 @@ static int intel_overlay_recover_from_interrupt(struct intel_overlay *overlay)
 	struct intel_engine_cs *ring = &dev_priv->ring[RCS];
 	int ret;
 
-	if (overlay->last_flip_req == 0)
+	if (overlay->last_flip_req == NULL)
 		return 0;
 
-	ret = i915_wait_seqno(ring, overlay->last_flip_req);
+	ret = i915_wait_seqno(ring, i915_gem_request_get_seqno(overlay->last_flip_req));
 	if (ret)
 		return ret;
 	i915_gem_retire_requests(dev);
@@ -377,7 +377,7 @@ static int intel_overlay_recover_from_interrupt(struct intel_overlay *overlay)
 	if (overlay->flip_tail)
 		overlay->flip_tail(overlay);
 
-	overlay->last_flip_req = 0;
+	overlay->last_flip_req = NULL;
 	return 0;
 }
 
-- 
1.7.9.5

[RFC 11/21] drm/i915: Convert i915_wait_seqno to i915_wait_request

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_drv.h         |   18 +-----------------
 drivers/gpu/drm/i915/i915_gem.c         |   30 +++++++++++++++---------------
 drivers/gpu/drm/i915/intel_lrc.c        |    6 ++----
 drivers/gpu/drm/i915/intel_overlay.c    |    9 +++------
 drivers/gpu/drm/i915/intel_ringbuffer.c |   14 ++++++--------
 5 files changed, 27 insertions(+), 50 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 9504206..4ce4ae6 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2530,8 +2530,7 @@ int __i915_add_request(struct intel_engine_cs *ring,
 		       u32 *seqno);
 #define i915_add_request(ring, seqno) \
 	__i915_add_request(ring, NULL, NULL, seqno)
-int __must_check i915_wait_seqno(struct intel_engine_cs *ring,
-				 uint32_t seqno);
+int __must_check i915_wait_request(struct drm_i915_gem_request *req);
 int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
 int __must_check
 i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj,
@@ -3020,19 +3019,4 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 	}
 }
 
-/************************* Deprecated *************************/
-static inline int __must_check i915_gem_check_ols(struct intel_engine_cs *ring, u32 seqno)
-{
-	int ret;
-
-	BUG_ON(!mutex_is_locked(&ring->dev->struct_mutex));
-
-	ret = 0;
-	if (seqno == i915_gem_request_get_seqno(ring->outstanding_lazy_request))
-		ret = i915_add_request(ring, NULL);
-
-	return ret;
-}
-/************************* Deprecated *************************/
-
 #endif
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 2c7deca..30731d4 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1252,29 +1252,34 @@ static int __wait_seqno(struct intel_engine_cs *ring, u32 seqno,
 }
 
 /**
- * Waits for a sequence number to be signaled, and cleans up the
+ * Waits for a request to be signaled, and cleans up the
  * request and object lists appropriately for that event.
  */
 int
-i915_wait_seqno(struct intel_engine_cs *ring, uint32_t seqno)
+i915_wait_request(struct drm_i915_gem_request *req)
 {
-	struct drm_device *dev = ring->dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	bool interruptible = dev_priv->mm.interruptible;
+	struct drm_device *dev;
+	struct drm_i915_private *dev_priv;
+	bool interruptible;
 	int ret;
 
+	BUG_ON(req == NULL);
+
+	dev = req->ring->dev;
+	dev_priv = dev->dev_private;
+	interruptible = dev_priv->mm.interruptible;
+
 	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
-	BUG_ON(seqno == 0);
 
 	ret = i915_gem_check_wedge(&dev_priv->gpu_error, interruptible);
 	if (ret)
 		return ret;
 
-	ret = i915_gem_check_ols(ring, seqno);
+	ret = i915_gem_check_olr(req);
 	if (ret)
 		return ret;
 
-	return __wait_seqno(ring, seqno,
+	return __wait_seqno(req->ring, i915_gem_request_get_seqno(req),
 			    atomic_read(&dev_priv->gpu_error.reset_counter),
 			    interruptible, NULL, NULL);
 }
@@ -1306,18 +1311,13 @@ i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj,
 			       bool readonly)
 {
 	struct drm_i915_gem_request *req;
-	struct intel_engine_cs *ring = obj->ring;
-	u32 seqno;
 	int ret;
 
 	req = readonly ? obj->last_write_req : obj->last_read_req;
 	if (!req)
 		return 0;
 
-	seqno = i915_gem_request_get_seqno(req);
-	BUG_ON(seqno == 0);
-
-	ret = i915_wait_seqno(ring, seqno);
+	ret = i915_wait_request(req);
 	if (ret)
 		return ret;
 
@@ -3234,7 +3234,7 @@ static int
 i915_gem_object_wait_fence(struct drm_i915_gem_object *obj)
 {
 	if (obj->last_fenced_req) {
-		int ret = i915_wait_seqno(obj->ring, i915_gem_request_get_seqno(obj->last_fenced_req));
+		int ret = i915_wait_request(obj->last_fenced_req);
 		if (ret)
 			return ret;
 
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 7005745..0b68fc7 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -830,7 +830,6 @@ static int logical_ring_wait_request(struct intel_ringbuffer *ringbuf,
 {
 	struct intel_engine_cs *ring = ringbuf->ring;
 	struct drm_i915_gem_request *request;
-	u32 seqno = 0;
 	int ret;
 
 	if (ringbuf->last_retired_head != -1) {
@@ -845,15 +844,14 @@ static int logical_ring_wait_request(struct intel_ringbuffer *ringbuf,
 	list_for_each_entry(request, &ring->request_list, list) {
 		if (__intel_ring_space(request->tail, ringbuf->tail,
 				       ringbuf->size) >= bytes) {
-			seqno = request->seqno;
 			break;
 		}
 	}
 
-	if (seqno == 0)
+	if (&request->list == &ring->request_list)
 		return -ENOSPC;
 
-	ret = i915_wait_seqno(ring, seqno);
+	ret = i915_wait_request(request);
 	if (ret)
 		return ret;
 
diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
index ccd5732..27ff4a2 100644
--- a/drivers/gpu/drm/i915/intel_overlay.c
+++ b/drivers/gpu/drm/i915/intel_overlay.c
@@ -222,7 +222,7 @@ static int intel_overlay_do_wait_request(struct intel_overlay *overlay,
 		return ret;
 
 	overlay->flip_tail = tail;
-	ret = i915_wait_seqno(ring, i915_gem_request_get_seqno(overlay->last_flip_req));
+	ret = i915_wait_request(overlay->last_flip_req);
 	if (ret)
 		return ret;
 	i915_gem_retire_requests(dev);
@@ -361,18 +361,15 @@ static int intel_overlay_off(struct intel_overlay *overlay)
  * We have to be careful not to repeat work forever an make forward progess. */
 static int intel_overlay_recover_from_interrupt(struct intel_overlay *overlay)
 {
-	struct drm_device *dev = overlay->dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_engine_cs *ring = &dev_priv->ring[RCS];
 	int ret;
 
 	if (overlay->last_flip_req == NULL)
 		return 0;
 
-	ret = i915_wait_seqno(ring, i915_gem_request_get_seqno(overlay->last_flip_req));
+	ret = i915_wait_request(overlay->last_flip_req);
 	if (ret)
 		return ret;
-	i915_gem_retire_requests(dev);
+	i915_gem_retire_requests(overlay->dev);
 
 	if (overlay->flip_tail)
 		overlay->flip_tail(overlay);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index dd59691..1be1934 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1868,7 +1868,6 @@ static int intel_ring_wait_request(struct intel_engine_cs *ring, int n)
 {
 	struct intel_ringbuffer *ringbuf = ring->buffer;
 	struct drm_i915_gem_request *request;
-	u32 seqno = 0;
 	int ret;
 
 	if (ringbuf->last_retired_head != -1) {
@@ -1883,15 +1882,14 @@ static int intel_ring_wait_request(struct intel_engine_cs *ring, int n)
 	list_for_each_entry(request, &ring->request_list, list) {
 		if (__intel_ring_space(request->tail, ringbuf->tail,
 				       ringbuf->size) >= n) {
-			seqno = request->seqno;
 			break;
 		}
 	}
 
-	if (seqno == 0)
+	if (&request->list == &ring->request_list)
 		return -ENOSPC;
 
-	ret = i915_wait_seqno(ring, seqno);
+	ret = i915_wait_request(request);
 	if (ret)
 		return ret;
 
@@ -1987,7 +1985,7 @@ static int intel_wrap_ring_buffer(struct intel_engine_cs *ring)
 
 int intel_ring_idle(struct intel_engine_cs *ring)
 {
-	u32 seqno;
+	struct drm_i915_gem_request *req;
 	int ret;
 
 	/* We need to add any requests required to flush the objects and ring */
@@ -2001,11 +1999,11 @@ int intel_ring_idle(struct intel_engine_cs *ring)
 	if (list_empty(&ring->request_list))
 		return 0;
 
-	seqno = list_entry(ring->request_list.prev,
+	req = list_entry(ring->request_list.prev,
 			   struct drm_i915_gem_request,
-			   list)->seqno;
+			   list);
 
-	return i915_wait_seqno(ring, seqno);
+	return i915_wait_request(req);
 }
 
 static int
-- 
1.7.9.5

[RFC 12/21] drm/i915: Convert 'i915_add_request' to take a request not a seqno

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_drv.h      |    6 +++---
 drivers/gpu/drm/i915/i915_gem.c      |    6 +++---
 drivers/gpu/drm/i915/intel_overlay.c |    4 ++--
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 4ce4ae6..6fe3be0 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2527,9 +2527,9 @@ int __must_check i915_gem_suspend(struct drm_device *dev);
 int __i915_add_request(struct intel_engine_cs *ring,
 		       struct drm_file *file,
 		       struct drm_i915_gem_object *batch_obj,
-		       u32 *seqno);
-#define i915_add_request(ring, seqno) \
-	__i915_add_request(ring, NULL, NULL, seqno)
+		       struct drm_i915_gem_request **out_req);
+#define i915_add_request(ring, out_req) \
+	__i915_add_request(ring, NULL, NULL, out_req)
 int __must_check i915_wait_request(struct drm_i915_gem_request *req);
 int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
 int __must_check
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 30731d4..b28e39b 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2331,7 +2331,7 @@ i915_gem_get_seqno(struct drm_device *dev, u32 *seqno)
 int __i915_add_request(struct intel_engine_cs *ring,
 		       struct drm_file *file,
 		       struct drm_i915_gem_object *obj,
-		       u32 *out_seqno)
+		       struct drm_i915_gem_request **out_req)
 {
 	struct drm_i915_private *dev_priv = ring->dev->dev_private;
 	struct drm_i915_gem_request *request;
@@ -2434,8 +2434,8 @@ int __i915_add_request(struct intel_engine_cs *ring,
 		intel_mark_busy(dev_priv->dev);
 	}
 
-	if (out_seqno)
-		*out_seqno = request->seqno;
+	if (out_req)
+		*out_req = request;
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
index 27ff4a2..942f91a 100644
--- a/drivers/gpu/drm/i915/intel_overlay.c
+++ b/drivers/gpu/drm/i915/intel_overlay.c
@@ -217,7 +217,7 @@ static int intel_overlay_do_wait_request(struct intel_overlay *overlay,
 	int ret;
 
 	BUG_ON(overlay->last_flip_req);
-	ret = i915_add_request(ring, &overlay->last_flip_req->seqno);
+	ret = i915_add_request(ring, &overlay->last_flip_req);
 	if (ret)
 		return ret;
 
@@ -286,7 +286,7 @@ static int intel_overlay_continue(struct intel_overlay *overlay,
 	intel_ring_emit(ring, flip_addr);
 	intel_ring_advance(ring);
 
-	return i915_add_request(ring, &overlay->last_flip_req->seqno);
+	return i915_add_request(ring, &overlay->last_flip_req);
 }
 
 static void intel_overlay_release_old_vid_tail(struct intel_overlay *overlay)
-- 
1.7.9.5

[RFC 13/21] drm/i915: Convert mmio_flip::seqno to struct request

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/intel_display.c |   12 +++++++-----
 drivers/gpu/drm/i915/intel_drv.h     |    2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2af421e..f13bc30 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9799,15 +9799,16 @@ void intel_notify_mmio_flip(struct intel_engine_cs *ring)
 		struct intel_mmio_flip *mmio_flip;
 
 		mmio_flip = &intel_crtc->mmio_flip;
-		if (mmio_flip->seqno == 0)
+		if (mmio_flip->req == NULL)
 			continue;
 
 		if (ring->id != mmio_flip->ring_id)
 			continue;
 
-		if (i915_seqno_passed(seqno, mmio_flip->seqno)) {
+		if (i915_seqno_passed(seqno, i915_gem_request_get_seqno(mmio_flip->req))) {
 			intel_do_mmio_flip(intel_crtc);
-			mmio_flip->seqno = 0;
+			i915_gem_request_unreference(mmio_flip->req);
+			mmio_flip->req = NULL;
 			ring->irq_put(ring);
 		}
 	}
@@ -9826,7 +9827,7 @@ static int intel_queue_mmio_flip(struct drm_device *dev,
 	unsigned long irq_flags;
 	int ret;
 
-	if (WARN_ON(intel_crtc->mmio_flip.seqno))
+	if (WARN_ON(intel_crtc->mmio_flip.req))
 		return -EBUSY;
 
 	ret = intel_postpone_flip(obj);
@@ -9838,7 +9839,8 @@ static int intel_queue_mmio_flip(struct drm_device *dev,
 	}
 
 	spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
-	intel_crtc->mmio_flip.seqno = i915_gem_request_get_seqno(obj->last_write_req);
+	intel_crtc->mmio_flip.req = obj->last_write_req;
+	i915_gem_request_reference(intel_crtc->mmio_flip.req);
 	intel_crtc->mmio_flip.ring_id = obj->ring->id;
 	spin_unlock_irqrestore(&dev_priv->mmio_flip_lock, irq_flags);
 
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index dd5e0f1..418ac13 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -395,7 +395,7 @@ struct intel_pipe_wm {
 };
 
 struct intel_mmio_flip {
-	u32 seqno;
+	struct drm_i915_gem_request *req;
 	u32 ring_id;
 };
 
-- 
1.7.9.5

[RFC 14/21] drm/i915: Convert 'flip_queued_seqno' into 'flip_queued_request'

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_debugfs.c  |    4 ++--
 drivers/gpu/drm/i915/intel_display.c |    9 ++++++---
 drivers/gpu/drm/i915/intel_drv.h     |    2 +-
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 726a8f0..52ddd19 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -547,11 +547,11 @@ static int i915_gem_pageflip_info(struct seq_file *m, void *data)
 			if (work->flip_queued_ring) {
 				seq_printf(m, "Flip queued on %s at seqno %u, next seqno %u [current breadcrumb %u], completed? %d\n",
 					   work->flip_queued_ring->name,
-					   work->flip_queued_seqno,
+					   i915_gem_request_get_seqno(work->flip_queued_req),
 					   dev_priv->next_seqno,
 					   work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
 					   i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
-							     work->flip_queued_seqno));
+							     i915_gem_request_get_seqno(work->flip_queued_req)));
 			} else
 				seq_printf(m, "Flip not associated with any ring\n");
 			seq_printf(m, "Flip queued on frame %d, (was ready on frame %d), now %d\n",
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f13bc30..26fdd96 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9879,7 +9879,7 @@ static bool __intel_pageflip_stall_check(struct drm_device *dev,
 	if (work->flip_ready_vblank == 0) {
 		if (work->flip_queued_ring &&
 		    !i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
-				       work->flip_queued_seqno))
+				       i915_gem_request_get_seqno(work->flip_queued_req)))
 			return false;
 
 		work->flip_ready_vblank = drm_vblank_count(dev, intel_crtc->pipe);
@@ -10047,7 +10047,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 		if (ret)
 			goto cleanup_unpin;
 
-		work->flip_queued_seqno = i915_gem_request_get_seqno(obj->last_write_req);
+		work->flip_queued_req = obj->last_write_req;
 		work->flip_queued_ring = obj->ring;
 	} else {
 		ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, ring,
@@ -10055,10 +10055,13 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 		if (ret)
 			goto cleanup_unpin;
 
-		work->flip_queued_seqno = i915_gem_request_get_seqno(intel_ring_get_request(ring));
+		work->flip_queued_req = intel_ring_get_request(ring);
 		work->flip_queued_ring = ring;
 	}
 
+	if (work->flip_queued_req)
+		i915_gem_request_reference(work->flip_queued_req);
+
 	work->flip_queued_vblank = drm_vblank_count(dev, intel_crtc->pipe);
 	work->enable_stall_check = true;
 
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 418ac13..cb5af63 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -687,7 +687,7 @@ struct intel_unpin_work {
 	u32 flip_count;
 	u32 gtt_offset;
 	struct intel_engine_cs *flip_queued_ring;
-	u32 flip_queued_seqno;
+	struct drm_i915_gem_request *flip_queued_req;
 	int flip_queued_vblank;
 	int flip_ready_vblank;
 	bool enable_stall_check;
-- 
1.7.9.5

[RFC 15/21] drm/i915: Convert most 'i915_seqno_passed' calls into 'i915_gem_request_completed'

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_debugfs.c     |    3 +--
 drivers/gpu/drm/i915/i915_drv.h         |   17 +++++++++++++++++
 drivers/gpu/drm/i915/i915_gem.c         |   12 ++++--------
 drivers/gpu/drm/i915/intel_display.c    |   11 +++--------
 drivers/gpu/drm/i915/intel_lrc.c        |    1 +
 drivers/gpu/drm/i915/intel_ringbuffer.c |    1 +
 6 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 52ddd19..e764af9 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -550,8 +550,7 @@ static int i915_gem_pageflip_info(struct seq_file *m, void *data)
 					   i915_gem_request_get_seqno(work->flip_queued_req),
 					   dev_priv->next_seqno,
 					   work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
-					   i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
-							     i915_gem_request_get_seqno(work->flip_queued_req)));
+					   i915_gem_request_completed(work->flip_queued_req, true));
 			} else
 				seq_printf(m, "Flip not associated with any ring\n");
 			seq_printf(m, "Flip queued on frame %d, (was ready on frame %d), now %d\n",
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6fe3be0..0790593 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1970,6 +1970,8 @@ i915_gem_request_unreference(struct drm_i915_gem_request *req)
 	kref_put(&req->ref, i915_gem_request_free);
 }
 
+/* ??? i915_gem_request_completed should be here ??? */
+
 struct drm_i915_file_private {
 	struct drm_i915_private *dev_priv;
 	struct drm_file *file;
@@ -3019,4 +3021,19 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 	}
 }
 
+static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
+					      bool lazy_coherency)
+{
+	u32 seqno;
+
+	BUG_ON(req == NULL);
+
+	if (req->ring == NULL)
+		return false;
+
+	seqno = req->ring->get_seqno(req->ring, lazy_coherency);
+
+	return i915_seqno_passed(seqno, req->seqno);
+}
+
 #endif
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index b28e39b..d4657e7 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2253,8 +2253,7 @@ i915_gem_object_retire(struct drm_i915_gem_object *obj)
 	if (ring == NULL)
 		return;
 
-	if (i915_seqno_passed(ring->get_seqno(ring, true),
-			      i915_gem_request_get_seqno(obj->last_read_req)))
+	if (i915_gem_request_completed(obj->last_read_req, true))
 		i915_gem_object_move_to_inactive(obj);
 }
 
@@ -2522,12 +2521,9 @@ struct drm_i915_gem_request *
 i915_gem_find_active_request(struct intel_engine_cs *ring)
 {
 	struct drm_i915_gem_request *request;
-	u32 completed_seqno;
-
-	completed_seqno = ring->get_seqno(ring, false);
 
 	list_for_each_entry(request, &ring->request_list, list) {
-		if (i915_seqno_passed(completed_seqno, request->seqno))
+		if (i915_gem_request_completed(request, false))
 			continue;
 
 		return request;
@@ -2671,7 +2667,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
 				      struct drm_i915_gem_object,
 				      ring_list);
 
-		if (!i915_seqno_passed(seqno, i915_gem_request_get_seqno(obj->last_read_req)))
+		if (!i915_gem_request_completed(obj->last_read_req, true))
 			break;
 
 		i915_gem_object_move_to_inactive(obj);
@@ -2686,7 +2682,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
 					   struct drm_i915_gem_request,
 					   list);
 
-		if (!i915_seqno_passed(seqno, request->seqno))
+		if (!i915_gem_request_completed(request, true))
 			break;
 
 		trace_i915_gem_request_retire(ring, request->seqno);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 26fdd96..9ca8f94 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9771,8 +9771,7 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
 
 	ring = obj->ring;
 
-	if (i915_seqno_passed(ring->get_seqno(ring, true),
-			      i915_gem_request_get_seqno(obj->last_write_req)))
+	if (i915_gem_request_completed(obj->last_write_req, true))
 		return 0;
 
 	ret = i915_gem_check_olr(obj->last_write_req);
@@ -9790,9 +9789,6 @@ void intel_notify_mmio_flip(struct intel_engine_cs *ring)
 	struct drm_i915_private *dev_priv = to_i915(ring->dev);
 	struct intel_crtc *intel_crtc;
 	unsigned long irq_flags;
-	u32 seqno;
-
-	seqno = ring->get_seqno(ring, false);
 
 	spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
 	for_each_intel_crtc(ring->dev, intel_crtc) {
@@ -9805,7 +9801,7 @@ void intel_notify_mmio_flip(struct intel_engine_cs *ring)
 		if (ring->id != mmio_flip->ring_id)
 			continue;
 
-		if (i915_seqno_passed(seqno, i915_gem_request_get_seqno(mmio_flip->req))) {
+		if (i915_gem_request_completed(mmio_flip->req, false)) {
 			intel_do_mmio_flip(intel_crtc);
 			i915_gem_request_unreference(mmio_flip->req);
 			mmio_flip->req = NULL;
@@ -9878,8 +9874,7 @@ static bool __intel_pageflip_stall_check(struct drm_device *dev,
 
 	if (work->flip_ready_vblank == 0) {
 		if (work->flip_queued_ring &&
-		    !i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
-				       i915_gem_request_get_seqno(work->flip_queued_req)))
+		    !i915_gem_request_completed(work->flip_queued_req, true))
 			return false;
 
 		work->flip_ready_vblank = drm_vblank_count(dev, intel_crtc->pipe);
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 0b68fc7..744684a 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -807,6 +807,7 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
 		return -ENOMEM;
 
 	kref_init(&request->ref);
+	request->ring = NULL;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 1be1934..4bbccdf 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2020,6 +2020,7 @@ intel_ring_alloc_seqno(struct intel_engine_cs *ring)
 		return -ENOMEM;
 
 	kref_init(&request->ref);
+	request->ring = NULL;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
-- 
1.7.9.5

[RFC 16/21] drm/i915: Convert __wait_seqno() to __wait_request()

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_gem.c |   57 +++++++++++++++++----------------------
 1 file changed, 24 insertions(+), 33 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index d4657e7..f1e64d8 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1133,10 +1133,9 @@ static bool can_wait_boost(struct drm_i915_file_private *file_priv)
 }
 
 /**
- * __wait_seqno - wait until execution of seqno has finished
- * @ring: the ring expected to report seqno
- * @seqno: duh!
- * @reset_counter: reset sequence associated with the given seqno
+ * __wait_request - wait until execution of request has finished
+ * @req: duh!
+ * @reset_counter: reset sequence associated with the given request
  * @interruptible: do an interruptible wait (normally yes)
  * @timeout: in - how long to wait (NULL forever); out - how much time remaining
  *
@@ -1147,15 +1146,16 @@ static bool can_wait_boost(struct drm_i915_file_private *file_priv)
  * reset_counter _must_ be read before, and an appropriate smp_rmb must be
  * inserted.
  *
- * Returns 0 if the seqno was found within the alloted time. Else returns the
+ * Returns 0 if the request was found within the alloted time. Else returns the
  * errno with remaining time filled in timeout argument.
  */
-static int __wait_seqno(struct intel_engine_cs *ring, u32 seqno,
-			unsigned reset_counter,
-			bool interruptible,
-			s64 *timeout,
-			struct drm_i915_file_private *file_priv)
+static int __wait_request(struct drm_i915_gem_request *req,
+			  unsigned reset_counter,
+			  bool interruptible,
+			  s64 *timeout,
+			  struct drm_i915_file_private *file_priv)
 {
+	struct intel_engine_cs *ring = i915_gem_request_get_ring(req);
 	struct drm_device *dev = ring->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	const bool irq_test_in_progress =
@@ -1167,7 +1167,7 @@ static int __wait_seqno(struct intel_engine_cs *ring, u32 seqno,
 
 	WARN(!intel_irqs_enabled(dev_priv), "IRQs disabled");
 
-	if (i915_seqno_passed(ring->get_seqno(ring, true), seqno))
+	if (i915_gem_request_completed(req, true))
 		return 0;
 
 	timeout_expire = timeout ? jiffies + nsecs_to_jiffies((u64)*timeout) : 0;
@@ -1184,7 +1184,7 @@ static int __wait_seqno(struct intel_engine_cs *ring, u32 seqno,
 		return -ENODEV;
 
 	/* Record current time in case interrupted by signal, or wedged */
-	trace_i915_gem_request_wait_begin(ring, seqno);
+	trace_i915_gem_request_wait_begin(i915_gem_request_get_ring(req), i915_gem_request_get_seqno(req));
 	before = ktime_get_raw_ns();
 	for (;;) {
 		struct timer_list timer;
@@ -1203,7 +1203,7 @@ static int __wait_seqno(struct intel_engine_cs *ring, u32 seqno,
 			break;
 		}
 
-		if (i915_seqno_passed(ring->get_seqno(ring, false), seqno)) {
+		if (i915_gem_request_completed(req, false)) {
 			ret = 0;
 			break;
 		}
@@ -1235,7 +1235,7 @@ static int __wait_seqno(struct intel_engine_cs *ring, u32 seqno,
 		}
 	}
 	now = ktime_get_raw_ns();
-	trace_i915_gem_request_wait_end(ring, seqno);
+	trace_i915_gem_request_wait_end(i915_gem_request_get_ring(req), i915_gem_request_get_seqno(req));
 
 	if (!irq_test_in_progress)
 		ring->irq_put(ring);
@@ -1279,9 +1279,9 @@ i915_wait_request(struct drm_i915_gem_request *req)
 	if (ret)
 		return ret;
 
-	return __wait_seqno(req->ring, i915_gem_request_get_seqno(req),
-			    atomic_read(&dev_priv->gpu_error.reset_counter),
-			    interruptible, NULL, NULL);
+	return __wait_request(req,
+			      atomic_read(&dev_priv->gpu_error.reset_counter),
+			      interruptible, NULL, NULL);
 }
 
 static int
@@ -1335,7 +1335,6 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
 	struct drm_i915_gem_request *req;
 	struct drm_device *dev = obj->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_engine_cs *ring = obj->ring;
 	unsigned reset_counter;
 	int ret;
 
@@ -1357,7 +1356,7 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
 	reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter);
 	i915_gem_request_reference(req);
 	mutex_unlock(&dev->struct_mutex);
-	ret = __wait_seqno(ring, i915_gem_request_get_seqno(req), reset_counter, true, NULL, file_priv);
+	ret = __wait_request(req, reset_counter, true, NULL, file_priv);
 	mutex_lock(&dev->struct_mutex);
 	i915_gem_request_unreference(req);
 	if (ret)
@@ -2816,9 +2815,7 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 	struct drm_i915_gem_wait *args = data;
 	struct drm_i915_gem_object *obj;
 	struct drm_i915_gem_request *req;
-	struct intel_engine_cs *ring = NULL;
 	unsigned reset_counter;
-	u32 seqno = 0;
 	int ret = 0;
 
 	ret = i915_mutex_lock_interruptible(dev);
@@ -2840,9 +2837,6 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 		goto out;
 
 	req = obj->last_read_req;
-	seqno = i915_gem_request_get_seqno(req);
-	BUG_ON(seqno == 0);
-	ring = obj->ring;
 
 	/* Do this after OLR check to make sure we make forward progress polling
 	 * on this IOCTL with a timeout <=0 (like busy ioctl)
@@ -2857,8 +2851,8 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 	i915_gem_request_reference(req);
 	mutex_unlock(&dev->struct_mutex);
 
-	ret = __wait_seqno(ring, seqno, reset_counter, true, &args->timeout_ns,
-			   file->driver_priv);
+	ret = __wait_request(req, reset_counter, true, &args->timeout_ns,
+			     file->driver_priv);
 	mutex_lock(&dev->struct_mutex);
 	i915_gem_request_unreference(req);
 	mutex_unlock(&dev->struct_mutex);
@@ -4053,10 +4047,8 @@ i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct drm_i915_file_private *file_priv = file->driver_priv;
 	unsigned long recent_enough = jiffies - msecs_to_jiffies(20);
-	struct drm_i915_gem_request *request;
-	struct intel_engine_cs *ring = NULL;
+	struct drm_i915_gem_request *request, *target = NULL;
 	unsigned reset_counter;
-	u32 seqno = 0;
 	int ret;
 
 	ret = i915_gem_wait_for_error(&dev_priv->gpu_error);
@@ -4072,16 +4064,15 @@ i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file)
 		if (time_after_eq(request->emitted_jiffies, recent_enough))
 			break;
 
-		ring = request->ring;
-		seqno = request->seqno;
+		target = request;
 	}
 	reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter);
 	spin_unlock(&file_priv->mm.lock);
 
-	if (seqno == 0)
+	if (target == NULL)
 		return 0;
 
-	ret = __wait_seqno(ring, seqno, reset_counter, true, NULL, NULL);
+	ret = __wait_request(target, reset_counter, true, NULL, NULL);
 	if (ret == 0)
 		queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, 0);
 
-- 
1.7.9.5

[RFC 17/21] drm/i915: Convert trace functions from seqno to request

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_gem.c            |   10 +++---
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |    2 +-
 drivers/gpu/drm/i915/i915_trace.h          |   47 ++++++++++++++++------------
 3 files changed, 33 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index f1e64d8..18f3605 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1184,7 +1184,7 @@ static int __wait_request(struct drm_i915_gem_request *req,
 		return -ENODEV;
 
 	/* Record current time in case interrupted by signal, or wedged */
-	trace_i915_gem_request_wait_begin(i915_gem_request_get_ring(req), i915_gem_request_get_seqno(req));
+	trace_i915_gem_request_wait_begin(req);
 	before = ktime_get_raw_ns();
 	for (;;) {
 		struct timer_list timer;
@@ -1235,7 +1235,7 @@ static int __wait_request(struct drm_i915_gem_request *req,
 		}
 	}
 	now = ktime_get_raw_ns();
-	trace_i915_gem_request_wait_end(i915_gem_request_get_ring(req), i915_gem_request_get_seqno(req));
+	trace_i915_gem_request_wait_end(req);
 
 	if (!irq_test_in_progress)
 		ring->irq_put(ring);
@@ -2419,7 +2419,7 @@ int __i915_add_request(struct intel_engine_cs *ring,
 		spin_unlock(&file_priv->mm.lock);
 	}
 
-	trace_i915_gem_request_add(ring, request->seqno);
+	trace_i915_gem_request_add(request);
 	ring->outstanding_lazy_request = NULL;
 
 	if (!dev_priv->ums.mm_suspended) {
@@ -2684,7 +2684,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
 		if (!i915_gem_request_completed(request, true))
 			break;
 
-		trace_i915_gem_request_retire(ring, request->seqno);
+		trace_i915_gem_request_retire(request);
 
 		/* This is one of the few common intersection points
 		 * between legacy ringbuffer submission and execlists:
@@ -2902,7 +2902,7 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
 	if (ret)
 		return ret;
 
-	trace_i915_gem_ring_sync_to(from, to, seqno);
+	trace_i915_gem_ring_sync_to(from, to, obj->last_read_req);
 	ret = to->semaphore.sync_to(to, from, seqno);
 	if (!ret)
 		/* We use last_read_req because sync_to()
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index e0fdfae..9bb8415 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1170,7 +1170,7 @@ i915_gem_ringbuffer_submission(struct drm_device *dev, struct drm_file *file,
 			return ret;
 	}
 
-	trace_i915_gem_ring_dispatch(ring, i915_gem_request_get_seqno(intel_ring_get_request(ring)), flags);
+	trace_i915_gem_ring_dispatch(intel_ring_get_request(ring), flags);
 
 	i915_gem_execbuffer_move_to_active(vmas, ring);
 	i915_gem_execbuffer_retire_commands(dev, file, ring, batch_obj);
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index f5aa006..66616f7 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -328,8 +328,8 @@ TRACE_EVENT(i915_gem_evict_vm,
 TRACE_EVENT(i915_gem_ring_sync_to,
 	    TP_PROTO(struct intel_engine_cs *from,
 		     struct intel_engine_cs *to,
-		     u32 seqno),
-	    TP_ARGS(from, to, seqno),
+		     struct drm_i915_gem_request *req),
+	    TP_ARGS(from, to, req),
 
 	    TP_STRUCT__entry(
 			     __field(u32, dev)
@@ -342,7 +342,7 @@ TRACE_EVENT(i915_gem_ring_sync_to,
 			   __entry->dev = from->dev->primary->index;
 			   __entry->sync_from = from->id;
 			   __entry->sync_to = to->id;
-			   __entry->seqno = seqno;
+			   __entry->seqno = i915_gem_request_get_seqno(req);
 			   ),
 
 	    TP_printk("dev=%u, sync-from=%u, sync-to=%u, seqno=%u",
@@ -352,8 +352,8 @@ TRACE_EVENT(i915_gem_ring_sync_to,
 );
 
 TRACE_EVENT(i915_gem_ring_dispatch,
-	    TP_PROTO(struct intel_engine_cs *ring, u32 seqno, u32 flags),
-	    TP_ARGS(ring, seqno, flags),
+	    TP_PROTO(struct drm_i915_gem_request *req, u32 flags),
+	    TP_ARGS(req, flags),
 
 	    TP_STRUCT__entry(
 			     __field(u32, dev)
@@ -363,11 +363,13 @@ TRACE_EVENT(i915_gem_ring_dispatch,
 			     ),
 
 	    TP_fast_assign(
+			   struct intel_engine_cs *ring =
+						i915_gem_request_get_ring(req);
 			   __entry->dev = ring->dev->primary->index;
 			   __entry->ring = ring->id;
-			   __entry->seqno = seqno;
+			   __entry->seqno = i915_gem_request_get_seqno(req);
 			   __entry->flags = flags;
-			   i915_trace_irq_get(ring, seqno);
+			   i915_trace_irq_get(ring, __entry->seqno);
 			   ),
 
 	    TP_printk("dev=%u, ring=%u, seqno=%u, flags=%x",
@@ -398,8 +400,8 @@ TRACE_EVENT(i915_gem_ring_flush,
 );
 
 DECLARE_EVENT_CLASS(i915_gem_request,
-	    TP_PROTO(struct intel_engine_cs *ring, u32 seqno),
-	    TP_ARGS(ring, seqno),
+	    TP_PROTO(struct drm_i915_gem_request *req),
+	    TP_ARGS(req),
 
 	    TP_STRUCT__entry(
 			     __field(u32, dev)
@@ -408,9 +410,11 @@ DECLARE_EVENT_CLASS(i915_gem_request,
 			     ),
 
 	    TP_fast_assign(
+			   struct intel_engine_cs *ring =
+						i915_gem_request_get_ring(req);
 			   __entry->dev = ring->dev->primary->index;
 			   __entry->ring = ring->id;
-			   __entry->seqno = seqno;
+			   __entry->seqno = i915_gem_request_get_seqno(req);
 			   ),
 
 	    TP_printk("dev=%u, ring=%u, seqno=%u",
@@ -418,8 +422,8 @@ DECLARE_EVENT_CLASS(i915_gem_request,
 );
 
 DEFINE_EVENT(i915_gem_request, i915_gem_request_add,
-	    TP_PROTO(struct intel_engine_cs *ring, u32 seqno),
-	    TP_ARGS(ring, seqno)
+	    TP_PROTO(struct drm_i915_gem_request *req),
+	    TP_ARGS(req)
 );
 
 TRACE_EVENT(i915_gem_request_complete,
@@ -443,13 +447,13 @@ TRACE_EVENT(i915_gem_request_complete,
 );
 
 DEFINE_EVENT(i915_gem_request, i915_gem_request_retire,
-	    TP_PROTO(struct intel_engine_cs *ring, u32 seqno),
-	    TP_ARGS(ring, seqno)
+	    TP_PROTO(struct drm_i915_gem_request *req),
+	    TP_ARGS(req)
 );
 
 TRACE_EVENT(i915_gem_request_wait_begin,
-	    TP_PROTO(struct intel_engine_cs *ring, u32 seqno),
-	    TP_ARGS(ring, seqno),
+	    TP_PROTO(struct drm_i915_gem_request *req),
+	    TP_ARGS(req),
 
 	    TP_STRUCT__entry(
 			     __field(u32, dev)
@@ -465,10 +469,13 @@ TRACE_EVENT(i915_gem_request_wait_begin,
 	     * less desirable.
 	     */
 	    TP_fast_assign(
+			   struct intel_engine_cs *ring =
+						i915_gem_request_get_ring(req);
 			   __entry->dev = ring->dev->primary->index;
 			   __entry->ring = ring->id;
-			   __entry->seqno = seqno;
-			   __entry->blocking = mutex_is_locked(&ring->dev->struct_mutex);
+			   __entry->seqno = i915_gem_request_get_seqno(req);
+			   __entry->blocking =
+				     mutex_is_locked(&ring->dev->struct_mutex);
 			   ),
 
 	    TP_printk("dev=%u, ring=%u, seqno=%u, blocking=%s",
@@ -477,8 +484,8 @@ TRACE_EVENT(i915_gem_request_wait_begin,
 );
 
 DEFINE_EVENT(i915_gem_request, i915_gem_request_wait_end,
-	    TP_PROTO(struct intel_engine_cs *ring, u32 seqno),
-	    TP_ARGS(ring, seqno)
+	    TP_PROTO(struct drm_i915_gem_request *req),
+	    TP_ARGS(req)
 );
 
 DECLARE_EVENT_CLASS(i915_ring,
-- 
1.7.9.5

[RFC 18/21] drm/i915: Convert 'trace_irq' to use requests rather than seqnos

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

Note: i915_trace_irq_get is no longer inline as it requires accessing the
internals of the request structure. As i915_drv.h includes intel_ringbuffer.h,
an inline within the former is never going to be able to use details from the
latter.

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_gem.c         |   10 +++-------
 drivers/gpu/drm/i915/i915_trace.h       |    2 +-
 drivers/gpu/drm/i915/intel_ringbuffer.c |    8 ++++++++
 drivers/gpu/drm/i915/intel_ringbuffer.h |    8 ++------
 4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 18f3605..2e1ebad 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2646,15 +2646,11 @@ void i915_gem_reset(struct drm_device *dev)
 void
 i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
 {
-	uint32_t seqno;
-
 	if (list_empty(&ring->request_list))
 		return;
 
 	WARN_ON(i915_verify_lists(ring->dev));
 
-	seqno = ring->get_seqno(ring, true);
-
 	/* Move any buffers on the active list that are no longer referenced
 	 * by the ringbuffer to the flushing/inactive lists as appropriate,
 	 * before we free the context associated with the requests.
@@ -2707,10 +2703,10 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
 		i915_gem_free_request(request);
 	}
 
-	if (unlikely(ring->trace_irq_seqno &&
-		     i915_seqno_passed(seqno, ring->trace_irq_seqno))) {
+	if (unlikely(ring->trace_irq_req &&
+		     i915_gem_request_completed(ring->trace_irq_req, true))) {
 		ring->irq_put(ring);
-		ring->trace_irq_seqno = 0;
+		ring->trace_irq_req = NULL;
 	}
 
 	WARN_ON(i915_verify_lists(ring->dev));
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index 66616f7..c8e515d 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -369,7 +369,7 @@ TRACE_EVENT(i915_gem_ring_dispatch,
 			   __entry->ring = ring->id;
 			   __entry->seqno = i915_gem_request_get_seqno(req);
 			   __entry->flags = flags;
-			   i915_trace_irq_get(ring, __entry->seqno);
+			   i915_trace_irq_get(req);
 			   ),
 
 	    TP_printk("dev=%u, ring=%u, seqno=%u, flags=%x",
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 4bbccdf..c8ec78c 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2791,3 +2791,11 @@ intel_stop_ring_buffer(struct intel_engine_cs *ring)
 
 	stop_ring(ring);
 }
+
+void i915_trace_irq_get(struct drm_i915_gem_request *req)
+{
+	struct intel_engine_cs *ring = i915_gem_request_get_ring(req);
+
+	if (ring->trace_irq_req == NULL && ring->irq_get(ring))
+		ring->trace_irq_req = req;
+}
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 98b219d..5475046 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -142,7 +142,7 @@ struct  intel_engine_cs {
 
 	unsigned irq_refcount; /* protected by dev_priv->irq_lock */
 	u32		irq_enable_mask;	/* bitmask to enable ring interrupt */
-	u32		trace_irq_seqno;
+	struct drm_i915_gem_request *trace_irq_req;
 	bool __must_check (*irq_get)(struct intel_engine_cs *ring);
 	void		(*irq_put)(struct intel_engine_cs *ring);
 
@@ -435,11 +435,7 @@ intel_ring_get_request(struct intel_engine_cs *ring)
 	return ring->outstanding_lazy_request;
 }
 
-static inline void i915_trace_irq_get(struct intel_engine_cs *ring, u32 seqno)
-{
-	if (ring->trace_irq_seqno == 0 && ring->irq_get(ring))
-		ring->trace_irq_seqno = seqno;
-}
+void i915_trace_irq_get(struct drm_i915_gem_request *req);
 
 /* DRI warts */
 int intel_render_ring_init_dri(struct drm_device *dev, u64 start, u32 size);
-- 
1.7.9.5

[RFC 19/21] drm/i915: Convert semaphores to handle requests not seqnos

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_debugfs.c     |    3 ++-
 drivers/gpu/drm/i915/i915_gem.c         |   14 ++++++--------
 drivers/gpu/drm/i915/i915_gpu_error.c   |   12 ++++++++----
 drivers/gpu/drm/i915/intel_ringbuffer.c |   10 ++++++----
 drivers/gpu/drm/i915/intel_ringbuffer.h |    4 ++--
 5 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index e764af9..df53515 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2604,7 +2604,8 @@ static int i915_semaphore_status(struct seq_file *m, void *unused)
 	seq_puts(m, "\nSync seqno:\n");
 	for_each_ring(ring, dev_priv, i) {
 		for (j = 0; j < num_rings; j++) {
-			seq_printf(m, "  0x%08x ", ring->semaphore.sync_seqno[j]);
+			seq_printf(m, "  0x%08x ",
+				   i915_gem_request_get_seqno(ring->semaphore.sync_req[j]));
 		}
 		seq_putc(m, '\n');
 	}
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 2e1ebad..d40dad7 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2275,8 +2275,8 @@ i915_gem_init_seqno(struct drm_device *dev, u32 seqno)
 	for_each_ring(ring, dev_priv, i) {
 		intel_ring_init_seqno(ring, seqno);
 
-		for (j = 0; j < ARRAY_SIZE(ring->semaphore.sync_seqno); j++)
-			ring->semaphore.sync_seqno[j] = 0;
+		for (j = 0; j < ARRAY_SIZE(ring->semaphore.sync_req); j++)
+			ring->semaphore.sync_req[j] = NULL;
 	}
 
 	return 0;
@@ -2877,7 +2877,6 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
 		     struct intel_engine_cs *to)
 {
 	struct intel_engine_cs *from = obj->ring;
-	u32 seqno;
 	int ret, idx;
 
 	if (from == NULL || to == from)
@@ -2888,10 +2887,10 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
 
 	idx = intel_ring_sync_index(from, to);
 
-	seqno = i915_gem_request_get_seqno(obj->last_read_req);
 	/* Optimization: Avoid semaphore sync when we are sure we already
 	 * waited for an object with higher seqno */
-	if (seqno <= from->semaphore.sync_seqno[idx]) /* <--- broken?! needs to use i915_seqno_passed()??? */
+	if (i915_gem_request_get_seqno(obj->last_read_req) <=
+		i915_gem_request_get_seqno(from->semaphore.sync_req[idx])) /* <--- broken?! needs to use i915_seqno_passed()??? */
 		return 0;
 
 	ret = i915_gem_check_olr(obj->last_read_req);
@@ -2899,14 +2898,13 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
 		return ret;
 
 	trace_i915_gem_ring_sync_to(from, to, obj->last_read_req);
-	ret = to->semaphore.sync_to(to, from, seqno);
+	ret = to->semaphore.sync_to(to, from, obj->last_read_req);
 	if (!ret)
 		/* We use last_read_req because sync_to()
 		 * might have just caused seqno wrap under
 		 * the radar.
 		 */
-		from->semaphore.sync_seqno[idx] =
-				i915_gem_request_get_seqno(obj->last_read_req);
+		from->semaphore.sync_req[idx] = obj->last_read_req;
 
 	return ret;
 }
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 1b58390..9545d96 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -822,7 +822,8 @@ static void gen8_record_semaphore_state(struct drm_i915_private *dev_priv,
 		idx = intel_ring_sync_index(ring, to);
 
 		ering->semaphore_mboxes[idx] = tmp[signal_offset];
-		ering->semaphore_seqno[idx] = ring->semaphore.sync_seqno[idx];
+		ering->semaphore_seqno[idx] =
+		      i915_gem_request_get_seqno(ring->semaphore.sync_req[idx]);
 	}
 }
 
@@ -832,13 +833,16 @@ static void gen6_record_semaphore_state(struct drm_i915_private *dev_priv,
 {
 	ering->semaphore_mboxes[0] = I915_READ(RING_SYNC_0(ring->mmio_base));
 	ering->semaphore_mboxes[1] = I915_READ(RING_SYNC_1(ring->mmio_base));
-	ering->semaphore_seqno[0] = ring->semaphore.sync_seqno[0];
-	ering->semaphore_seqno[1] = ring->semaphore.sync_seqno[1];
+	ering->semaphore_seqno[0] =
+			i915_gem_request_get_seqno(ring->semaphore.sync_req[0]);
+	ering->semaphore_seqno[1] =
+			i915_gem_request_get_seqno(ring->semaphore.sync_req[1]);
 
 	if (HAS_VEBOX(dev_priv->dev)) {
 		ering->semaphore_mboxes[2] =
 			I915_READ(RING_SYNC_2(ring->mmio_base));
-		ering->semaphore_seqno[2] = ring->semaphore.sync_seqno[2];
+		ering->semaphore_seqno[2] =
+			i915_gem_request_get_seqno(ring->semaphore.sync_req[2]);
 	}
 }
 
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index c8ec78c..0a3c24a 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1042,7 +1042,7 @@ static inline bool i915_gem_has_seqno_wrapped(struct drm_device *dev,
 static int
 gen8_ring_sync(struct intel_engine_cs *waiter,
 	       struct intel_engine_cs *signaller,
-	       u32 seqno)
+	       struct drm_i915_gem_request *req)
 {
 	struct drm_i915_private *dev_priv = waiter->dev->dev_private;
 	int ret;
@@ -1055,7 +1055,7 @@ gen8_ring_sync(struct intel_engine_cs *waiter,
 				MI_SEMAPHORE_GLOBAL_GTT |
 				MI_SEMAPHORE_POLL |
 				MI_SEMAPHORE_SAD_GTE_SDD);
-	intel_ring_emit(waiter, seqno);
+	intel_ring_emit(waiter, i915_gem_request_get_seqno(req));
 	intel_ring_emit(waiter,
 			lower_32_bits(GEN8_WAIT_OFFSET(waiter, signaller->id)));
 	intel_ring_emit(waiter,
@@ -1067,18 +1067,20 @@ gen8_ring_sync(struct intel_engine_cs *waiter,
 static int
 gen6_ring_sync(struct intel_engine_cs *waiter,
 	       struct intel_engine_cs *signaller,
-	       u32 seqno)
+	       struct drm_i915_gem_request *req)
 {
 	u32 dw1 = MI_SEMAPHORE_MBOX |
 		  MI_SEMAPHORE_COMPARE |
 		  MI_SEMAPHORE_REGISTER;
 	u32 wait_mbox = signaller->semaphore.mbox.wait[waiter->id];
 	int ret;
+	u32 seqno;
 
 	/* Throughout all of the GEM code, seqno passed implies our current
 	 * seqno is >= the last seqno executed. However for hardware the
 	 * comparison is strictly greater than.
 	 */
+	seqno = i915_gem_request_get_seqno(req);
 	seqno -= 1;
 
 	WARN_ON(wait_mbox == MI_SEMAPHORE_SYNC_INVALID);
@@ -1794,7 +1796,7 @@ static int intel_init_ring_buffer(struct drm_device *dev,
 	INIT_LIST_HEAD(&ring->execlist_queue);
 	ringbuf->size = 32 * PAGE_SIZE;
 	ringbuf->ring = ring;
-	memset(ring->semaphore.sync_seqno, 0, sizeof(ring->semaphore.sync_seqno));
+	memset(ring->semaphore.sync_req, 0, sizeof(ring->semaphore.sync_req));
 
 	init_waitqueue_head(&ring->irq_queue);
 
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 5475046..64a4346 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -211,7 +211,7 @@ struct  intel_engine_cs {
 	 *  ie. transpose of f(x, y)
 	 */
 	struct {
-		u32	sync_seqno[I915_NUM_RINGS-1];
+		struct drm_i915_gem_request *sync_req[I915_NUM_RINGS-1];
 
 		union {
 			struct {
@@ -226,7 +226,7 @@ struct  intel_engine_cs {
 		/* AKA wait() */
 		int	(*sync_to)(struct intel_engine_cs *ring,
 				   struct intel_engine_cs *to,
-				   u32 seqno);
+				   struct drm_i915_gem_request *req);
 		int	(*signal)(struct intel_engine_cs *signaller,
 				  /* num_dwords needed by caller */
 				  unsigned int num_dwords);
-- 
1.7.9.5

[RFC 20/21] drm/i915: Convert 'ring_idle()' to use requests not seqnos

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_irq.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 4847ed5..c2a7127 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -3030,18 +3030,18 @@ static void gen8_disable_vblank(struct drm_device *dev, int pipe)
 	spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
 }
 
-static u32
-ring_last_seqno(struct intel_engine_cs *ring)
+static struct drm_i915_gem_request *
+ring_last_request(struct intel_engine_cs *ring)
 {
 	return list_entry(ring->request_list.prev,
-			  struct drm_i915_gem_request, list)->seqno;
+			  struct drm_i915_gem_request, list);
 }
 
 static bool
-ring_idle(struct intel_engine_cs *ring, u32 seqno)
+ring_idle(struct intel_engine_cs *ring)
 {
 	return (list_empty(&ring->request_list) ||
-		i915_seqno_passed(seqno, ring_last_seqno(ring)));
+		i915_gem_request_completed(ring_last_request(ring), false));
 }
 
 static bool
@@ -3261,7 +3261,7 @@ static void i915_hangcheck_elapsed(unsigned long data)
 		acthd = intel_ring_get_active_head(ring);
 
 		if (ring->hangcheck.seqno == seqno) {
-			if (ring_idle(ring, seqno)) {
+			if (ring_idle(ring)) {
 				ring->hangcheck.action = HANGCHECK_IDLE;
 
 				if (waitqueue_active(&ring->irq_queue)) {
-- 
1.7.9.5

[RFC 21/21] drm/i915: Remove 'obj->ring'

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_debugfs.c     |    9 +++++----
 drivers/gpu/drm/i915/i915_drv.h         |    2 --
 drivers/gpu/drm/i915/i915_gem.c         |   32 +++++++++++++++++++------------
 drivers/gpu/drm/i915/i915_gem_context.c |   12 +++++++++++-
 drivers/gpu/drm/i915/i915_gpu_error.c   |    3 ++-
 drivers/gpu/drm/i915/intel_display.c    |   15 ++++++++-------
 6 files changed, 46 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index df53515..b1d989f 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -168,8 +168,9 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj)
 		*t = '\0';
 		seq_printf(m, " (%s mappable)", s);
 	}
-	if (obj->ring != NULL)
-		seq_printf(m, " (%s)", obj->ring->name);
+	if (obj->last_read_req != NULL)
+		seq_printf(m, " (%s)",
+			   i915_gem_request_get_ring(obj->last_read_req)->name);
 	if (obj->frontbuffer_bits)
 		seq_printf(m, " (frontbuffer: 0x%03x)", obj->frontbuffer_bits);
 }
@@ -336,7 +337,7 @@ static int per_file_stats(int id, void *ptr, void *data)
 			if (ppgtt->file_priv != stats->file_priv)
 				continue;
 
-			if (obj->ring) /* XXX per-vma statistic */
+			if (obj->last_read_req) /* XXX per-vma statistic */
 				stats->active += obj->base.size;
 			else
 				stats->inactive += obj->base.size;
@@ -346,7 +347,7 @@ static int per_file_stats(int id, void *ptr, void *data)
 	} else {
 		if (i915_gem_obj_ggtt_bound(obj)) {
 			stats->global += obj->base.size;
-			if (obj->ring)
+			if (obj->last_read_req)
 				stats->active += obj->base.size;
 			else
 				stats->inactive += obj->base.size;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 0790593..cdbbdeb 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1859,8 +1859,6 @@ struct drm_i915_gem_object {
 	void *dma_buf_vmapping;
 	int vmapping_count;
 
-	struct intel_engine_cs *ring;
-
 	/** Breadcrumb of last rendering to the buffer. */
 	struct drm_i915_gem_request *last_read_req;
 	struct drm_i915_gem_request *last_write_req;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index d40dad7..561fb81 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2184,14 +2184,18 @@ static void
 i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
 			       struct intel_engine_cs *ring)
 {
-	struct drm_i915_gem_request *req = intel_ring_get_request(ring);
+	struct drm_i915_gem_request *req;
+	struct intel_engine_cs *old_ring;
 
 	BUG_ON(ring == NULL);
-	if (obj->ring != ring && obj->last_write_req) {
+
+	req = intel_ring_get_request(ring);
+	old_ring = i915_gem_request_get_ring(obj->last_read_req);
+
+	if (old_ring != ring && obj->last_write_req) {
 		/* Keep the request relative to the current ring */
 		obj->last_write_req = req;
 	}
-	obj->ring = ring;
 
 	/* Add a reference if we're newly entering the active list. */
 	if (!obj->active) {
@@ -2230,7 +2234,6 @@ i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
 	intel_fb_obj_flush(obj, true);
 
 	list_del_init(&obj->ring_list);
-	obj->ring = NULL;
 
 	obj->last_read_req = NULL;
 	obj->last_write_req = NULL;
@@ -2247,9 +2250,7 @@ i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
 static void
 i915_gem_object_retire(struct drm_i915_gem_object *obj)
 {
-	struct intel_engine_cs *ring = obj->ring;
-
-	if (ring == NULL)
+	if (obj->last_read_req == NULL)
 		return;
 
 	if (i915_gem_request_completed(obj->last_read_req, true))
@@ -2769,14 +2770,17 @@ i915_gem_idle_work_handler(struct work_struct *work)
 static int
 i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
 {
+	struct intel_engine_cs *ring;
 	int ret;
 
 	if (obj->active) {
+		ring = i915_gem_request_get_ring(obj->last_read_req);
+
 		ret = i915_gem_check_olr(obj->last_read_req);
 		if (ret)
 			return ret;
 
-		i915_gem_retire_requests_ring(obj->ring);
+		i915_gem_retire_requests_ring(ring);
 	}
 
 	return 0;
@@ -2876,9 +2880,11 @@ int
 i915_gem_object_sync(struct drm_i915_gem_object *obj,
 		     struct intel_engine_cs *to)
 {
-	struct intel_engine_cs *from = obj->ring;
+	struct intel_engine_cs *from;
 	int ret, idx;
 
+	from = i915_gem_request_get_ring(obj->last_read_req);
+
 	if (from == NULL || to == from)
 		return 0;
 
@@ -3889,7 +3895,7 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
 	bool was_pin_display;
 	int ret;
 
-	if (pipelined != obj->ring) {
+	if (pipelined != i915_gem_request_get_ring(obj->last_read_req)) {
 		ret = i915_gem_object_sync(obj, pipelined);
 		if (ret)
 			return ret;
@@ -4303,9 +4309,11 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
 	ret = i915_gem_object_flush_active(obj);
 
 	args->busy = obj->active;
-	if (obj->ring) {
+	if (obj->last_read_req) {
+		struct intel_engine_cs *ring;
 		BUILD_BUG_ON(I915_NUM_RINGS > 16);
-		args->busy |= intel_ring_flag(obj->ring) << 16;
+		ring = i915_gem_request_get_ring(obj->last_read_req);
+		args->busy |= intel_ring_flag(ring) << 16;
 	}
 
 	drm_gem_object_unreference(&obj->base);
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index a5221d8..8f24831 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -613,7 +613,17 @@ static int do_switch(struct intel_engine_cs *ring,
 		 * swapped, but there is no way to do that yet.
 		 */
 		from->legacy_hw_ctx.rcs_state->dirty = 1;
-		BUG_ON(from->legacy_hw_ctx.rcs_state->ring != ring);
+
+		/* BUG_ON(i915_gem_request_get_ring(
+			from->legacy_hw_ctx.rcs_state->last_read_req) != ring); */
+		/* NB: last_read_req has already been updated to the current
+		 * request however, that request has not yet been submitted.
+		 * Thus last_read_req->ring is guaranteed to be null!
+		 * NB2: Doing the check before the update of last_read_req
+		 * (which happens in i915_vma_move_to_active() just above),
+		 * also fails because last_read_req is almost always null on
+		 * entry!
+		 */
 
 		/* obj is kept alive until the next request by its active ref */
 		i915_gem_object_ggtt_unpin(from->legacy_hw_ctx.rcs_state);
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 9545d96..b9ecbd9 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -681,7 +681,8 @@ static void capture_bo(struct drm_i915_error_buffer *err,
 	err->dirty = obj->dirty;
 	err->purgeable = obj->madv != I915_MADV_WILLNEED;
 	err->userptr = obj->userptr.mm != NULL;
-	err->ring = obj->ring ? obj->ring->id : -1;
+	err->ring = obj->last_read_req ?
+			i915_gem_request_get_ring(obj->last_read_req)->id : -1;
 	err->cache_level = obj->cache_level;
 }
 
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 9ca8f94..8238aac 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9728,7 +9728,7 @@ static bool use_mmio_flip(struct intel_engine_cs *ring,
 	else if (i915.enable_execlists)
 		return true;
 	else
-		return ring != obj->ring;
+		return ring != i915_gem_request_get_ring(obj->last_read_req);
 }
 
 static void intel_do_mmio_flip(struct intel_crtc *intel_crtc)
@@ -9769,8 +9769,6 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
 	if (!obj->last_write_req)
 		return 0;
 
-	ring = obj->ring;
-
 	if (i915_gem_request_completed(obj->last_write_req, true))
 		return 0;
 
@@ -9778,6 +9776,7 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
 	if (ret)
 		return ret;
 
+	ring = i915_gem_request_get_ring(obj->last_write_req);
 	if (WARN_ON(!ring->irq_get(ring)))
 		return 0;
 
@@ -9837,14 +9836,15 @@ static int intel_queue_mmio_flip(struct drm_device *dev,
 	spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
 	intel_crtc->mmio_flip.req = obj->last_write_req;
 	i915_gem_request_reference(intel_crtc->mmio_flip.req);
-	intel_crtc->mmio_flip.ring_id = obj->ring->id;
+	BUG_ON(ring != i915_gem_request_get_ring(intel_crtc->mmio_flip.req));
+	intel_crtc->mmio_flip.ring_id = ring->id;
 	spin_unlock_irqrestore(&dev_priv->mmio_flip_lock, irq_flags);
 
 	/*
 	 * Double check to catch cases where irq fired before
 	 * mmio flip data was ready
 	 */
-	intel_notify_mmio_flip(obj->ring);
+	intel_notify_mmio_flip(ring);
 	return 0;
 }
 
@@ -10022,7 +10022,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 	} else if (IS_IVYBRIDGE(dev)) {
 		ring = &dev_priv->ring[BCS];
 	} else if (INTEL_INFO(dev)->gen >= 7) {
-		ring = obj->ring;
+		ring = i915_gem_request_get_ring(obj->last_read_req);
 		if (ring == NULL || ring->id != RCS)
 			ring = &dev_priv->ring[BCS];
 	} else {
@@ -10043,7 +10043,8 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 			goto cleanup_unpin;
 
 		work->flip_queued_req = obj->last_write_req;
-		work->flip_queued_ring = obj->ring;
+		work->flip_queued_ring =
+				i915_gem_request_get_ring(obj->last_write_req);
 	} else {
 		ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, ring,
 						   page_flip_flags);
-- 
1.7.9.5

Re: [RFC 01/21] Bug: missing i915_seqno_passed() call?

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:05PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> ---
>  drivers/gpu/drm/i915/i915_gem.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 2a5351d..8c68219 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2886,7 +2886,7 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
>  	seqno = obj->last_read_seqno;
>  	/* Optimization: Avoid semaphore sync when we are sure we already
>  	 * waited for an object with higher seqno */
> -	if (seqno <= from->semaphore.sync_seqno[idx])
> +	if (seqno <= from->semaphore.sync_seqno[idx]) /* <--- broken?! needs to use i915_seqno_passed()??? */

No, becuase hw semaphores don't wrap around so we actual need to check for
<=, not the wrap-around logic seqno_passed has. If you feel like pls
submit a patch to add a comment here.

btw you're threading looks a bit funny, instead of patches all being
in-reply-to the cover letter they're all in-reply-to the previous patch.
Presuming you don't have a funky .gitconfig recent git should do this in
the preferred form by default.
-Daniel

>  		return 0;
>  
>  	ret = i915_gem_check_olr(obj->ring, seqno);
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 01/21] Bug: missing i915_seqno_passed() call?

[John Harrison]

On 06/10/2014 15:45, Daniel Vetter wrote:
> On Mon, Oct 06, 2014 at 03:15:05PM +0100, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
>>
>> ---
>>   drivers/gpu/drm/i915/i915_gem.c |    2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
>> index 2a5351d..8c68219 100644
>> --- a/drivers/gpu/drm/i915/i915_gem.c
>> +++ b/drivers/gpu/drm/i915/i915_gem.c
>> @@ -2886,7 +2886,7 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
>>   	seqno = obj->last_read_seqno;
>>   	/* Optimization: Avoid semaphore sync when we are sure we already
>>   	 * waited for an object with higher seqno */
>> -	if (seqno <= from->semaphore.sync_seqno[idx])
>> +	if (seqno <= from->semaphore.sync_seqno[idx]) /* <--- broken?! needs to use i915_seqno_passed()??? */
> No, becuase hw semaphores don't wrap around so we actual need to check for
> <=, not the wrap-around logic seqno_passed has. If you feel like pls
> submit a patch to add a comment here.
I would prefer to remove the test completely and replace it with some 
request structure based operation. Unfortunately, I haven't worked out 
what yet.

> btw you're threading looks a bit funny, instead of patches all being
> in-reply-to the cover letter they're all in-reply-to the previous patch.
> Presuming you don't have a funky .gitconfig recent git should do this in
> the preferred form by default.
Phooey. Git-sendmail kept spewing warning messages about chain-reply-to 
having changed and needs to be sent explicitly in the config file to 
keep it quiet. I guess I set it the wrong way.

> -Daniel
>
>>   		return 0;
>>   
>>   	ret = i915_gem_check_olr(obj->ring, seqno);
>> -- 
>> 1.7.9.5
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [RFC 00/21] Replace seqno values with request structures

[Chris Wilson]

On Mon, Oct 06, 2014 at 03:15:04PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> Work in progress for replacing seqno usage with requst structures.

You fail to end up with my earlier code. Nak.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre

[RFC 22/21] drm/i915: Cache request completion status

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_drv.h         |   34 ++++++++++++++++---------------
 drivers/gpu/drm/i915/i915_gem.c         |   21 +++++++++++++++++++
 drivers/gpu/drm/i915/intel_lrc.c        |    1 +
 drivers/gpu/drm/i915/intel_ringbuffer.c |    2 ++
 drivers/gpu/drm/i915/intel_ringbuffer.h |    3 +++
 5 files changed, 45 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index cdbbdeb..4ab3b23 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1913,6 +1913,9 @@ void i915_gem_track_fb(struct drm_i915_gem_object *old,
 struct drm_i915_gem_request {
 	struct kref ref;
 
+	/** Is this request known to be complete? */
+	bool complete;
+
 	/** On Which ring this request was generated */
 	struct intel_engine_cs *ring;
 
@@ -1943,6 +1946,8 @@ struct drm_i915_gem_request {
 };
 
 void i915_gem_request_free(struct kref *req_ref);
+void i915_gem_complete_requests_ring(struct intel_engine_cs *ring,
+				     bool lazy_coherency);
 
 static inline uint32_t
 i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
@@ -1968,7 +1973,19 @@ i915_gem_request_unreference(struct drm_i915_gem_request *req)
 	kref_put(&req->ref, i915_gem_request_free);
 }
 
-/* ??? i915_gem_request_completed should be here ??? */
+static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
+					      bool lazy_coherency)
+{
+	if (req->complete)
+		return true;
+
+	if (req->ring == NULL)
+		return false;
+
+	i915_gem_complete_requests_ring(req->ring, lazy_coherency);
+
+	return req->complete;
+}
 
 struct drm_i915_file_private {
 	struct drm_i915_private *dev_priv;
@@ -3019,19 +3036,4 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 	}
 }
 
-static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
-					      bool lazy_coherency)
-{
-	u32 seqno;
-
-	BUG_ON(req == NULL);
-
-	if (req->ring == NULL)
-		return false;
-
-	seqno = req->ring->get_seqno(req->ring, lazy_coherency);
-
-	return i915_seqno_passed(seqno, req->seqno);
-}
-
 #endif
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 0f14333..0a9b29e 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2641,6 +2641,27 @@ void i915_gem_reset(struct drm_device *dev)
 	i915_gem_restore_fences(dev);
 }
 
+void i915_gem_complete_requests_ring(struct intel_engine_cs *ring,
+				     bool lazy_coherency)
+{
+	struct drm_i915_gem_request *req;
+	u32 seqno;
+
+	seqno = ring->get_seqno(ring, lazy_coherency);
+	if (seqno == ring->last_read_seqno)
+		return;
+
+	list_for_each_entry(req, &ring->request_list, list) {
+		if (req->complete)
+			continue;
+
+		if (i915_seqno_passed(seqno, req->seqno))
+			req->complete = true;
+	}
+
+	ring->last_read_seqno = seqno;
+}
+
 /**
  * This function clears the request list as sequence numbers are passed.
  */
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 744684a..57acd2a 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -808,6 +808,7 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
 
 	kref_init(&request->ref);
 	request->ring = NULL;
+	request->complete = false;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 0a3c24a..392dc25 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2023,6 +2023,7 @@ intel_ring_alloc_seqno(struct intel_engine_cs *ring)
 
 	kref_init(&request->ref);
 	request->ring = NULL;
+	request->complete = false;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
@@ -2115,6 +2116,7 @@ void intel_ring_init_seqno(struct intel_engine_cs *ring, u32 seqno)
 			I915_WRITE(RING_SYNC_2(ring->mmio_base), 0);
 	}
 
+	ring->last_read_seqno = 0;
 	ring->set_seqno(ring, seqno);
 	ring->hangcheck.seqno = seqno;
 }
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 64a4346..40394d3 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -269,6 +269,9 @@ struct  intel_engine_cs {
 	bool gpu_caches_dirty;
 	bool fbc_dirty;
 
+	/* For optimising request completion events */
+	u32 last_read_seqno;
+
 	wait_queue_head_t irq_queue;
 
 	struct intel_context *default_context;
-- 
1.7.9.5

[RFC 08/25] drm/i915: Remove 'outstanding_lazy_seqno'

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_gem.c            |   13 +++----
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |    2 +-
 drivers/gpu/drm/i915/intel_display.c       |    2 +-
 drivers/gpu/drm/i915/intel_lrc.c           |   26 +++++---------
 drivers/gpu/drm/i915/intel_ringbuffer.c    |   52 +++++++++++++++-------------
 drivers/gpu/drm/i915/intel_ringbuffer.h    |   13 ++-----
 6 files changed, 46 insertions(+), 62 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 9ce0808..c884188 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1108,7 +1108,7 @@ i915_gem_check_olr(struct intel_engine_cs *ring, u32 seqno)
 	BUG_ON(!mutex_is_locked(&ring->dev->struct_mutex));
 
 	ret = 0;
-	if (seqno == ring->outstanding_lazy_seqno)
+	if (seqno == i915_gem_request_get_seqno(ring->outstanding_lazy_request))
 		ret = i915_add_request(ring, NULL);
 
 	return ret;
@@ -2344,7 +2344,7 @@ int __i915_add_request(struct intel_engine_cs *ring,
 	u32 request_ring_position, request_start;
 	int ret;
 
-	request = ring->preallocated_lazy_request;
+	request = ring->outstanding_lazy_request;
 	if (WARN_ON(request == NULL))
 		return -ENOMEM;
 
@@ -2391,7 +2391,6 @@ int __i915_add_request(struct intel_engine_cs *ring,
 
 	i915_gem_request_reference(request);
 
-	request->seqno = intel_ring_get_seqno(ring);
 	request->ring = ring;
 	request->head = request_start;
 	request->tail = request_ring_position;
@@ -2428,8 +2427,7 @@ int __i915_add_request(struct intel_engine_cs *ring,
 	}
 
 	trace_i915_gem_request_add(ring, request->seqno);
-	ring->outstanding_lazy_seqno = 0;
-	ring->preallocated_lazy_request = NULL;
+	ring->outstanding_lazy_request = NULL;
 
 	if (!dev_priv->ums.mm_suspended) {
 		i915_queue_hangcheck(ring->dev);
@@ -2605,9 +2603,8 @@ static void i915_gem_reset_ring_cleanup(struct drm_i915_private *dev_priv,
 	}
 
 	/* These may not have been flush before the reset, do so now */
-	kfree(ring->preallocated_lazy_request);
-	ring->preallocated_lazy_request = NULL;
-	ring->outstanding_lazy_seqno = 0;
+	kfree(ring->outstanding_lazy_request);
+	ring->outstanding_lazy_request = NULL;
 }
 
 void i915_gem_restore_fences(struct drm_device *dev)
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 4250211..e0fdfae 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1170,7 +1170,7 @@ i915_gem_ringbuffer_submission(struct drm_device *dev, struct drm_file *file,
 			return ret;
 	}
 
-	trace_i915_gem_ring_dispatch(ring, intel_ring_get_seqno(ring), flags);
+	trace_i915_gem_ring_dispatch(ring, i915_gem_request_get_seqno(intel_ring_get_request(ring)), flags);
 
 	i915_gem_execbuffer_move_to_active(vmas, ring);
 	i915_gem_execbuffer_retire_commands(dev, file, ring, batch_obj);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5aae3d1e..6da18c5 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -10053,7 +10053,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 		if (ret)
 			goto cleanup_unpin;
 
-		work->flip_queued_seqno = intel_ring_get_seqno(ring);
+		work->flip_queued_seqno = i915_gem_request_get_seqno(intel_ring_get_request(ring));
 		work->flip_queued_ring = ring;
 	}
 
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index b5b6430..55c607a 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -793,22 +793,14 @@ void intel_logical_ring_advance_and_submit(struct intel_ringbuffer *ringbuf)
 	execlists_context_queue(ring, ctx, ringbuf->tail);
 }
 
-static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
-				    struct intel_context *ctx)
+static int logical_ring_alloc_request(struct intel_engine_cs *ring,
+				      struct intel_context *ctx)
 {
 	struct drm_i915_gem_request *request;
 	int ret;
 
-	/* The aim is to replace seqno values with request structures. A step
-	 * along the way is to switch to using the PLR in preference to the
-	 * OLS. That requires the PLR to only be valid when the OLS is also
-	 * valid. I.e., the two must be kept in step. */
-
-	if (ring->outstanding_lazy_seqno) {
-		BUG_ON(ring->preallocated_lazy_request == NULL);
+	if (ring->outstanding_lazy_request)
 		return 0;
-	}
-	BUG_ON(ring->preallocated_lazy_request != NULL);
 
 	request = kmalloc(sizeof(*request), GFP_KERNEL);
 	if (request == NULL)
@@ -816,7 +808,7 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
 
 	kref_init(&request->ref);
 
-	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
+	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
 		kfree(request);
 		return ret;
@@ -829,7 +821,7 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
 	request->ctx = ctx;
 	i915_gem_context_reference(request->ctx);
 
-	ring->preallocated_lazy_request = request;
+	ring->outstanding_lazy_request = request;
 	return 0;
 }
 
@@ -997,7 +989,7 @@ int intel_logical_ring_begin(struct intel_ringbuffer *ringbuf, int num_dwords)
 		return ret;
 
 	/* Preallocate the olr before touching the ring */
-	ret = logical_ring_alloc_seqno(ring, ringbuf->FIXME_lrc_ctx);
+	ret = logical_ring_alloc_request(ring, ringbuf->FIXME_lrc_ctx);
 	if (ret)
 		return ret;
 
@@ -1212,7 +1204,8 @@ static int gen8_emit_request(struct intel_ringbuffer *ringbuf)
 				(ring->status_page.gfx_addr +
 				(I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT)));
 	intel_logical_ring_emit(ringbuf, 0);
-	intel_logical_ring_emit(ringbuf, ring->outstanding_lazy_seqno);
+	intel_logical_ring_emit(ringbuf,
+		i915_gem_request_get_seqno(ring->outstanding_lazy_request));
 	intel_logical_ring_emit(ringbuf, MI_USER_INTERRUPT);
 	intel_logical_ring_emit(ringbuf, MI_NOOP);
 	intel_logical_ring_advance_and_submit(ringbuf);
@@ -1235,8 +1228,7 @@ void intel_logical_ring_cleanup(struct intel_engine_cs *ring)
 
 	intel_logical_ring_stop(ring);
 	WARN_ON((I915_READ_MODE(ring) & MODE_IDLE) == 0);
-	ring->preallocated_lazy_request = NULL;
-	ring->outstanding_lazy_seqno = 0;
+	ring->outstanding_lazy_request = NULL;
 
 	if (ring->cleanup)
 		ring->cleanup(ring);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 7350f78..99544bc 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -895,17 +895,20 @@ static int gen8_rcs_signal(struct intel_engine_cs *signaller,
 		return ret;
 
 	for_each_ring(waiter, dev_priv, i) {
+		u32 seqno;
 		u64 gtt_offset = signaller->semaphore.signal_ggtt[i];
 		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
 			continue;
 
+		seqno = i915_gem_request_get_seqno(
+					   signaller->outstanding_lazy_request);
 		intel_ring_emit(signaller, GFX_OP_PIPE_CONTROL(6));
 		intel_ring_emit(signaller, PIPE_CONTROL_GLOBAL_GTT_IVB |
 					   PIPE_CONTROL_QW_WRITE |
 					   PIPE_CONTROL_FLUSH_ENABLE);
 		intel_ring_emit(signaller, lower_32_bits(gtt_offset));
 		intel_ring_emit(signaller, upper_32_bits(gtt_offset));
-		intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
+		intel_ring_emit(signaller, seqno);
 		intel_ring_emit(signaller, 0);
 		intel_ring_emit(signaller, MI_SEMAPHORE_SIGNAL |
 					   MI_SEMAPHORE_TARGET(waiter->id));
@@ -933,16 +936,19 @@ static int gen8_xcs_signal(struct intel_engine_cs *signaller,
 		return ret;
 
 	for_each_ring(waiter, dev_priv, i) {
+		u32 seqno;
 		u64 gtt_offset = signaller->semaphore.signal_ggtt[i];
 		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
 			continue;
 
+		seqno = i915_gem_request_get_seqno(
+					   signaller->outstanding_lazy_request);
 		intel_ring_emit(signaller, (MI_FLUSH_DW + 1) |
 					   MI_FLUSH_DW_OP_STOREDW);
 		intel_ring_emit(signaller, lower_32_bits(gtt_offset) |
 					   MI_FLUSH_DW_USE_GTT);
 		intel_ring_emit(signaller, upper_32_bits(gtt_offset));
-		intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
+		intel_ring_emit(signaller, seqno);
 		intel_ring_emit(signaller, MI_SEMAPHORE_SIGNAL |
 					   MI_SEMAPHORE_TARGET(waiter->id));
 		intel_ring_emit(signaller, 0);
@@ -971,9 +977,11 @@ static int gen6_signal(struct intel_engine_cs *signaller,
 	for_each_ring(useless, dev_priv, i) {
 		u32 mbox_reg = signaller->semaphore.mbox.signal[i];
 		if (mbox_reg != GEN6_NOSYNC) {
+			u32 seqno = i915_gem_request_get_seqno(
+					   signaller->outstanding_lazy_request);
 			intel_ring_emit(signaller, MI_LOAD_REGISTER_IMM(1));
 			intel_ring_emit(signaller, mbox_reg);
-			intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
+			intel_ring_emit(signaller, seqno);
 		}
 	}
 
@@ -1008,7 +1016,8 @@ gen6_add_request(struct intel_engine_cs *ring)
 
 	intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
 	intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
-	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
+	intel_ring_emit(ring,
+		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
 	intel_ring_emit(ring, MI_USER_INTERRUPT);
 	__intel_ring_advance(ring);
 
@@ -1126,7 +1135,8 @@ pc_render_add_request(struct intel_engine_cs *ring)
 			PIPE_CONTROL_WRITE_FLUSH |
 			PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE);
 	intel_ring_emit(ring, ring->scratch.gtt_offset | PIPE_CONTROL_GLOBAL_GTT);
-	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
+	intel_ring_emit(ring,
+		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
 	intel_ring_emit(ring, 0);
 	PIPE_CONTROL_FLUSH(ring, scratch_addr);
 	scratch_addr += 2 * CACHELINE_BYTES; /* write to separate cachelines */
@@ -1145,7 +1155,8 @@ pc_render_add_request(struct intel_engine_cs *ring)
 			PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE |
 			PIPE_CONTROL_NOTIFY);
 	intel_ring_emit(ring, ring->scratch.gtt_offset | PIPE_CONTROL_GLOBAL_GTT);
-	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
+	intel_ring_emit(ring,
+		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
 	intel_ring_emit(ring, 0);
 	__intel_ring_advance(ring);
 
@@ -1385,7 +1396,8 @@ i9xx_add_request(struct intel_engine_cs *ring)
 
 	intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
 	intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
-	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
+	intel_ring_emit(ring,
+		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
 	intel_ring_emit(ring, MI_USER_INTERRUPT);
 	__intel_ring_advance(ring);
 
@@ -1839,8 +1851,7 @@ void intel_cleanup_ring_buffer(struct intel_engine_cs *ring)
 	WARN_ON(!IS_GEN2(ring->dev) && (I915_READ_MODE(ring) & MODE_IDLE) == 0);
 
 	intel_destroy_ringbuffer_obj(ringbuf);
-	ring->preallocated_lazy_request = NULL;
-	ring->outstanding_lazy_seqno = 0;
+	ring->outstanding_lazy_request = NULL;
 
 	if (ring->cleanup)
 		ring->cleanup(ring);
@@ -1980,7 +1991,7 @@ int intel_ring_idle(struct intel_engine_cs *ring)
 	int ret;
 
 	/* We need to add any requests required to flush the objects and ring */
-	if (ring->outstanding_lazy_seqno) {
+	if (ring->outstanding_lazy_request) {
 		ret = i915_add_request(ring, NULL);
 		if (ret)
 			return ret;
@@ -1998,22 +2009,13 @@ int intel_ring_idle(struct intel_engine_cs *ring)
 }
 
 static int
-intel_ring_alloc_seqno(struct intel_engine_cs *ring)
+intel_ring_alloc_request(struct intel_engine_cs *ring)
 {
 	int ret;
 	struct drm_i915_gem_request *request;
 
-	/* The aim is to replace seqno values with request structures. A step
-	 * along the way is to switch to using the PLR in preference to the
-	 * OLS. That requires the PLR to only be valid when the OLS is also
-	 * valid. I.e., the two must be kept in step. */
-
-	if (ring->outstanding_lazy_seqno) {
-		BUG_ON(ring->preallocated_lazy_request == NULL);
+	if (ring->outstanding_lazy_request)
 		return 0;
-	}
-
-	BUG_ON(ring->preallocated_lazy_request != NULL);
 
 	request = kmalloc(sizeof(*request), GFP_KERNEL);
 	if (request == NULL)
@@ -2021,13 +2023,13 @@ intel_ring_alloc_seqno(struct intel_engine_cs *ring)
 
 	kref_init(&request->ref);
 
-	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
+	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
 		kfree(request);
 		return ret;
 	}
 
-	ring->preallocated_lazy_request = request;
+	ring->outstanding_lazy_request = request;
 	return 0;
 }
 
@@ -2068,7 +2070,7 @@ int intel_ring_begin(struct intel_engine_cs *ring,
 		return ret;
 
 	/* Preallocate the olr before touching the ring */
-	ret = intel_ring_alloc_seqno(ring);
+	ret = intel_ring_alloc_request(ring);
 	if (ret)
 		return ret;
 
@@ -2103,7 +2105,7 @@ void intel_ring_init_seqno(struct intel_engine_cs *ring, u32 seqno)
 	struct drm_device *dev = ring->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	BUG_ON(ring->outstanding_lazy_seqno);
+	BUG_ON(ring->outstanding_lazy_request);
 
 	if (INTEL_INFO(dev)->gen == 6 || INTEL_INFO(dev)->gen == 7) {
 		I915_WRITE(RING_SYNC_0(ring->mmio_base), 0);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index d98b964..98b219d 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -265,8 +265,7 @@ struct  intel_engine_cs {
 	/**
 	 * Do we have some not yet emitted requests outstanding?
 	 */
-	struct drm_i915_gem_request *preallocated_lazy_request;
-	u32 outstanding_lazy_seqno;
+	struct drm_i915_gem_request *outstanding_lazy_request;
 	bool gpu_caches_dirty;
 	bool fbc_dirty;
 
@@ -429,17 +428,11 @@ static inline u32 intel_ring_get_tail(struct intel_ringbuffer *ringbuf)
 	return ringbuf->tail;
 }
 
-static inline u32 intel_ring_get_seqno(struct intel_engine_cs *ring)
-{
-	BUG_ON(ring->outstanding_lazy_seqno == 0);
-	return ring->outstanding_lazy_seqno;
-}
-
 static inline struct drm_i915_gem_request *
 intel_ring_get_request(struct intel_engine_cs *ring)
 {
-	BUG_ON(ring->preallocated_lazy_request == NULL);
-	return ring->preallocated_lazy_request;
+	BUG_ON(ring->outstanding_lazy_request == NULL);
+	return ring->outstanding_lazy_request;
 }
 
 static inline void i915_trace_irq_get(struct intel_engine_cs *ring, u32 seqno)
-- 
1.7.9.5

[RFC 15/25] drm/i915: Connect requests to rings at creation not submission

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_gem.c         |    1 -
 drivers/gpu/drm/i915/intel_lrc.c        |    1 +
 drivers/gpu/drm/i915/intel_ringbuffer.c |    1 +
 3 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index bbf8974..e1a58f1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2386,7 +2386,6 @@ int __i915_add_request(struct intel_engine_cs *ring,
 
 	i915_gem_request_reference(request);
 
-	request->ring = ring;
 	request->head = request_start;
 	request->tail = request_ring_position;
 
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 90d4d51..c4a5a90 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -807,6 +807,7 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring,
 		return -ENOMEM;
 
 	kref_init(&request->ref);
+	request->ring = ring;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 4af59ac..f018c67 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2020,6 +2020,7 @@ intel_ring_alloc_request(struct intel_engine_cs *ring)
 		return -ENOMEM;
 
 	kref_init(&request->ref);
+	request->ring = ring;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
-- 
1.7.9.5

[RFC 16/25] drm/i915: Convert most 'i915_seqno_passed' calls into 'i915_gem_request_completed'

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_debugfs.c  |    3 +--
 drivers/gpu/drm/i915/i915_drv.h      |   18 ++++++++++++++++++
 drivers/gpu/drm/i915/i915_gem.c      |   12 ++++--------
 drivers/gpu/drm/i915/intel_display.c |   11 +++--------
 4 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 52ddd19..e764af9 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -550,8 +550,7 @@ static int i915_gem_pageflip_info(struct seq_file *m, void *data)
 					   i915_gem_request_get_seqno(work->flip_queued_req),
 					   dev_priv->next_seqno,
 					   work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
-					   i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
-							     i915_gem_request_get_seqno(work->flip_queued_req)));
+					   i915_gem_request_completed(work->flip_queued_req, true));
 			} else
 				seq_printf(m, "Flip not associated with any ring\n");
 			seq_printf(m, "Flip queued on frame %d, (was ready on frame %d), now %d\n",
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6fe3be0..650f712 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1970,6 +1970,12 @@ i915_gem_request_unreference(struct drm_i915_gem_request *req)
 	kref_put(&req->ref, i915_gem_request_free);
 }
 
+/*
+ * NB: i915_gem_request_completed should be here but currently needs the
+ * definition of i915_seqno_passed() which is below. It will be moved in
+ * a later patch when the call to i915_seqno_passed() is obsoleted...
+ */
+
 struct drm_i915_file_private {
 	struct drm_i915_private *dev_priv;
 	struct drm_file *file;
@@ -3019,4 +3025,16 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 	}
 }
 
+static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
+					      bool lazy_coherency)
+{
+	u32 seqno;
+
+	BUG_ON(req == NULL);
+
+	seqno = req->ring->get_seqno(req->ring, lazy_coherency);
+
+	return i915_seqno_passed(seqno, req->seqno);
+}
+
 #endif
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e1a58f1..b602e8c 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2253,8 +2253,7 @@ i915_gem_object_retire(struct drm_i915_gem_object *obj)
 	if (ring == NULL)
 		return;
 
-	if (i915_seqno_passed(ring->get_seqno(ring, true),
-			      i915_gem_request_get_seqno(obj->last_read_req)))
+	if (i915_gem_request_completed(obj->last_read_req, true))
 		i915_gem_object_move_to_inactive(obj);
 }
 
@@ -2521,12 +2520,9 @@ struct drm_i915_gem_request *
 i915_gem_find_active_request(struct intel_engine_cs *ring)
 {
 	struct drm_i915_gem_request *request;
-	u32 completed_seqno;
-
-	completed_seqno = ring->get_seqno(ring, false);
 
 	list_for_each_entry(request, &ring->request_list, list) {
-		if (i915_seqno_passed(completed_seqno, request->seqno))
+		if (i915_gem_request_completed(request, false))
 			continue;
 
 		return request;
@@ -2670,7 +2666,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
 				      struct drm_i915_gem_object,
 				      ring_list);
 
-		if (!i915_seqno_passed(seqno, i915_gem_request_get_seqno(obj->last_read_req)))
+		if (!i915_gem_request_completed(obj->last_read_req, true))
 			break;
 
 		i915_gem_object_move_to_inactive(obj);
@@ -2685,7 +2681,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
 					   struct drm_i915_gem_request,
 					   list);
 
-		if (!i915_seqno_passed(seqno, request->seqno))
+		if (!i915_gem_request_completed(request, true))
 			break;
 
 		trace_i915_gem_request_retire(ring, request->seqno);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 26fdd96..9ca8f94 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9771,8 +9771,7 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
 
 	ring = obj->ring;
 
-	if (i915_seqno_passed(ring->get_seqno(ring, true),
-			      i915_gem_request_get_seqno(obj->last_write_req)))
+	if (i915_gem_request_completed(obj->last_write_req, true))
 		return 0;
 
 	ret = i915_gem_check_olr(obj->last_write_req);
@@ -9790,9 +9789,6 @@ void intel_notify_mmio_flip(struct intel_engine_cs *ring)
 	struct drm_i915_private *dev_priv = to_i915(ring->dev);
 	struct intel_crtc *intel_crtc;
 	unsigned long irq_flags;
-	u32 seqno;
-
-	seqno = ring->get_seqno(ring, false);
 
 	spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
 	for_each_intel_crtc(ring->dev, intel_crtc) {
@@ -9805,7 +9801,7 @@ void intel_notify_mmio_flip(struct intel_engine_cs *ring)
 		if (ring->id != mmio_flip->ring_id)
 			continue;
 
-		if (i915_seqno_passed(seqno, i915_gem_request_get_seqno(mmio_flip->req))) {
+		if (i915_gem_request_completed(mmio_flip->req, false)) {
 			intel_do_mmio_flip(intel_crtc);
 			i915_gem_request_unreference(mmio_flip->req);
 			mmio_flip->req = NULL;
@@ -9878,8 +9874,7 @@ static bool __intel_pageflip_stall_check(struct drm_device *dev,
 
 	if (work->flip_ready_vblank == 0) {
 		if (work->flip_queued_ring &&
-		    !i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
-				       i915_gem_request_get_seqno(work->flip_queued_req)))
+		    !i915_gem_request_completed(work->flip_queued_req, true))
 			return false;
 
 		work->flip_ready_vblank = drm_vblank_count(dev, intel_crtc->pipe);
-- 
1.7.9.5

[RFC 23/25] drm/i915: Cache request completion status

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_drv.h         |   32 +++++++++++++++----------------
 drivers/gpu/drm/i915/i915_gem.c         |   21 ++++++++++++++++++++
 drivers/gpu/drm/i915/intel_lrc.c        |    1 +
 drivers/gpu/drm/i915/intel_ringbuffer.c |    2 ++
 drivers/gpu/drm/i915/intel_ringbuffer.h |    3 +++
 5 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 7b0b1e2..e46c78c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1913,6 +1913,9 @@ void i915_gem_track_fb(struct drm_i915_gem_object *old,
 struct drm_i915_gem_request {
 	struct kref ref;
 
+	/** Is this request known to be complete? */
+	bool complete;
+
 	/** On Which ring this request was generated */
 	struct intel_engine_cs *ring;
 
@@ -1943,6 +1946,8 @@ struct drm_i915_gem_request {
 };
 
 void i915_gem_request_free(struct kref *req_ref);
+void i915_gem_complete_requests_ring(struct intel_engine_cs *ring,
+				     bool lazy_coherency);
 
 static inline uint32_t
 i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
@@ -1968,11 +1973,16 @@ i915_gem_request_unreference(struct drm_i915_gem_request *req)
 	kref_put(&req->ref, i915_gem_request_free);
 }
 
-/*
- * NB: i915_gem_request_completed should be here but currently needs the
- * definition of i915_seqno_passed() which is below. It will be moved in
- * a later patch when the call to i915_seqno_passed() is obsoleted...
- */
+static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
+					      bool lazy_coherency)
+{
+	if (req->complete)
+		return true;
+
+	i915_gem_complete_requests_ring(req->ring, lazy_coherency);
+
+	return req->complete;
+}
 
 struct drm_i915_file_private {
 	struct drm_i915_private *dev_priv;
@@ -3023,16 +3033,4 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 	}
 }
 
-static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
-					      bool lazy_coherency)
-{
-	u32 seqno;
-
-	BUG_ON(req == NULL);
-
-	seqno = req->ring->get_seqno(req->ring, lazy_coherency);
-
-	return i915_seqno_passed(seqno, req->seqno);
-}
-
 #endif
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index b72bff1..260ef47 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2640,6 +2640,27 @@ void i915_gem_reset(struct drm_device *dev)
 	i915_gem_restore_fences(dev);
 }
 
+void i915_gem_complete_requests_ring(struct intel_engine_cs *ring,
+				     bool lazy_coherency)
+{
+	struct drm_i915_gem_request *req;
+	u32 seqno;
+
+	seqno = ring->get_seqno(ring, lazy_coherency);
+	if (seqno == ring->last_read_seqno)
+		return;
+
+	list_for_each_entry(req, &ring->request_list, list) {
+		if (req->complete)
+			continue;
+
+		if (i915_seqno_passed(seqno, req->seqno))
+			req->complete = true;
+	}
+
+	ring->last_read_seqno = seqno;
+}
+
 /**
  * This function clears the request list as sequence numbers are passed.
  */
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index c4a5a90..97e6b92 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -808,6 +808,7 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring,
 
 	kref_init(&request->ref);
 	request->ring = ring;
+	request->complete = false;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index dc6135c..df9c7e3 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2023,6 +2023,7 @@ intel_ring_alloc_request(struct intel_engine_cs *ring)
 
 	kref_init(&request->ref);
 	request->ring = ring;
+	request->complete = false;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
@@ -2115,6 +2116,7 @@ void intel_ring_init_seqno(struct intel_engine_cs *ring, u32 seqno)
 			I915_WRITE(RING_SYNC_2(ring->mmio_base), 0);
 	}
 
+	ring->last_read_seqno = 0;
 	ring->set_seqno(ring, seqno);
 	ring->hangcheck.seqno = seqno;
 }
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 64a4346..40394d3 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -269,6 +269,9 @@ struct  intel_engine_cs {
 	bool gpu_caches_dirty;
 	bool fbc_dirty;
 
+	/* For optimising request completion events */
+	u32 last_read_seqno;
+
 	wait_queue_head_t irq_queue;
 
 	struct intel_context *default_context;
-- 
1.7.9.5

[RFC 24/25] drm/i915: Zero fill the request structure

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/intel_lrc.c        |    3 +--
 drivers/gpu/drm/i915/intel_ringbuffer.c |    3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 97e6b92..5a75eb5 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -802,13 +802,12 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring,
 	if (ring->outstanding_lazy_request)
 		return 0;
 
-	request = kmalloc(sizeof(*request), GFP_KERNEL);
+	request = kzalloc(sizeof(*request), GFP_KERNEL);
 	if (request == NULL)
 		return -ENOMEM;
 
 	kref_init(&request->ref);
 	request->ring = ring;
-	request->complete = false;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index df9c7e3..0f2719d 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2017,13 +2017,12 @@ intel_ring_alloc_request(struct intel_engine_cs *ring)
 	if (ring->outstanding_lazy_request)
 		return 0;
 
-	request = kmalloc(sizeof(*request), GFP_KERNEL);
+	request = kzalloc(sizeof(*request), GFP_KERNEL);
 	if (request == NULL)
 		return -ENOMEM;
 
 	kref_init(&request->ref);
 	request->ring = ring;
-	request->complete = false;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
-- 
1.7.9.5

[RFC 25/25] drm/i915: Defer seqno allocation until actual hardware submission time

[John.C.Harrison]

From: John Harrison <John.C.Harrison@Intel.com>

For: VIZ-4377
Signed-off-by: John.C.Harrison@Intel.com
---
 drivers/gpu/drm/i915/i915_drv.h         |    5 ++++-
 drivers/gpu/drm/i915/i915_gem.c         |   28 +++++++++++++++++++++++++++-
 drivers/gpu/drm/i915/intel_lrc.c        |   10 ++++------
 drivers/gpu/drm/i915/intel_ringbuffer.c |   10 ++++------
 4 files changed, 39 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e46c78c..d797975 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1979,6 +1979,9 @@ static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
 	if (req->complete)
 		return true;
 
+	if (req->seqno == 0)
+		return false;
+
 	i915_gem_complete_requests_ring(req->ring, lazy_coherency);
 
 	return req->complete;
@@ -2482,7 +2485,7 @@ i915_seqno_passed(uint32_t seq1, uint32_t seq2)
 	return (int32_t)(seq1 - seq2) >= 0;
 }
 
-int __must_check i915_gem_get_seqno(struct drm_device *dev, u32 *seqno);
+int __must_check i915_gem_prepare_next_seqno(struct drm_device *dev);
 int __must_check i915_gem_set_seqno(struct drm_device *dev, u32 seqno);
 int __must_check i915_gem_object_get_fence(struct drm_i915_gem_object *obj);
 int __must_check i915_gem_object_put_fence(struct drm_i915_gem_object *obj);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 260ef47..7db84b2 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2310,12 +2310,15 @@ int i915_gem_set_seqno(struct drm_device *dev, u32 seqno)
 }
 
 int
-i915_gem_get_seqno(struct drm_device *dev, u32 *seqno)
+i915_gem_prepare_next_seqno(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
 	/* reserve 0 for non-seqno */
 	if (dev_priv->next_seqno == 0) {
+		/* Why is the full re-initialisation required? Is it only for
+		 * hardware semaphores? If so, could skip it in the case where
+		 * semaphores are disabled? */
 		int ret = i915_gem_init_seqno(dev, 0);
 		if (ret)
 			return ret;
@@ -2323,6 +2326,24 @@ i915_gem_get_seqno(struct drm_device *dev, u32 *seqno)
 		dev_priv->next_seqno = 1;
 	}
 
+	return 0;
+}
+
+static int
+i915_gem_get_seqno(struct drm_device *dev, u32 *seqno)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	/* reserve 0 for non-seqno */
+	if (dev_priv->next_seqno == 0) {
+		/* Should never get here! Must always call 'prepare_next' in
+		 * advance. This code is called during request submission.
+		 * Trying to wrap the seqno and the implicit idle() calls that
+		 * the wrap code makes are a bad idea at this point! */
+		DRM_ERROR("Need to wrap seqno at inopportune moment!\n");
+		return -EBUSY;
+	}
+
 	*seqno = dev_priv->last_seqno = dev_priv->next_seqno++;
 	return 0;
 }
@@ -2366,6 +2387,11 @@ int __i915_add_request(struct intel_engine_cs *ring,
 			return ret;
 	}
 
+	/* Assign an identifier to track this request through the hardware: */
+	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
+	if (ret)
+		return ret;
+
 	/* Record the position of the start of the request so that
 	 * should we detect the updated seqno part-way through the
 	 * GPU processing the request, we never over-estimate the
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 5a75eb5..e7d4d20 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -802,6 +802,10 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring,
 	if (ring->outstanding_lazy_request)
 		return 0;
 
+	ret = i915_gem_prepare_next_seqno(ring->dev);
+	if (ret)
+		return ret;
+
 	request = kzalloc(sizeof(*request), GFP_KERNEL);
 	if (request == NULL)
 		return -ENOMEM;
@@ -809,12 +813,6 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring,
 	kref_init(&request->ref);
 	request->ring = ring;
 
-	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
-	if (ret) {
-		kfree(request);
-		return ret;
-	}
-
 	/* Hold a reference to the context this request belongs to
 	 * (we will need it when the time comes to emit/retire the
 	 * request).
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 0f2719d..6a2f25d 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2017,6 +2017,10 @@ intel_ring_alloc_request(struct intel_engine_cs *ring)
 	if (ring->outstanding_lazy_request)
 		return 0;
 
+	ret = i915_gem_prepare_next_seqno(ring->dev);
+	if (ret)
+		return ret;
+
 	request = kzalloc(sizeof(*request), GFP_KERNEL);
 	if (request == NULL)
 		return -ENOMEM;
@@ -2024,12 +2028,6 @@ intel_ring_alloc_request(struct intel_engine_cs *ring)
 	kref_init(&request->ref);
 	request->ring = ring;
 
-	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
-	if (ret) {
-		kfree(request);
-		return ret;
-	}
-
 	ring->outstanding_lazy_request = request;
 	return 0;
 }
-- 
1.7.9.5

Re: [RFC 00/21] Replace seqno values with request structures

[John Harrison]

[-- Attachment #1.1: Type: text/plain, Size: 5513 bytes --]

I have just posted an updated subset of the patch series. Note that one 
patch has been inserted in the middle and the first one has been 
dropped. The correct sequence is now:

    01    drm/i915: Remove redundant parameter to
    i915_gem_object_wait_rendering__tail()
    02    drm/i915: Ensure OLS & PLR are always in sync
    03    drm/i915: Add reference count to request structure
    04    drm/i915: Add helper functions to aid seqno -> request transition
    05    drm/i915: Replace last_[rwf]_seqno with last_[rwf]_req
    06    drm/i915: Ensure requests stick around during waits
    07    drm/i915: Remove 'outstanding_lazy_seqno'
    08    drm/i915: Make 'i915_gem_check_olr' actually check by request
    not seqno
    09    drm/i915: Convert 'last_flip_req' to be a request not a seqno
    10    drm/i915: Convert i915_wait_seqno to i915_wait_request
    11    drm/i915: Convert 'i915_add_request' to take a request not a seqno
    12    drm/i915: Convert mmio_flip::seqno to struct request
    13    drm/i915: Convert 'flip_queued_seqno' into 'flip_queued_request'
    14    drm/i915: Connect requests to rings at creation not submission
    15    drm/i915: Convert most 'i915_seqno_passed' calls into
    'i915_gem_request_completed'
    16    drm/i915: Convert __wait_seqno() to __wait_request()
    17    drm/i915: Convert trace functions from seqno to request
    18    drm/i915: Convert 'trace_irq' to use requests rather than seqnos
    19    drm/i915: Convert semaphores to handle requests not seqnos
    20    drm/i915: Convert 'ring_idle()' to use requests not seqnos
    21    drm/i915: Remove 'obj->ring'
    22    drm/i915: Cache request completion status
    23    drm/i915: Zero fill the request structure
    24    drm/i915: Defer seqno allocation until actual hardware
    submission time


The whole set in its latest and greatest form has also been uploaded to 
the drm-private git as 'topic/seqno-request'.


On 06/10/2014 15:15, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
>
> Work in progress for replacing seqno usage with requst structures.
>
> There is a general feeling that it is better to move away from using a simple
> integer 'seqno' value to track batch buffer completion. Instead, the request
> structure should be used. That provides for much more flexibility going
> forwards. Especially which things like a GPU scheduler (which can re-order batch
> buffers and hence seqnos after submission to the hardware), Android sync points
> and other such features which potentially make seqno usage more and more
> complex.
>
> The current set of patches do most of the seqno to request structure conversion.
> There are still a couple of direct seqno comparisons in the semaphore code. The
> final conversion of a seqno test into a 'completed' flag inside the request
> structure is still do to as well. Along with whatever changes are required to
> maintain such a flag.
>
> The patches are being posted now to make sure that the various people involved
> agree that it is heading in the right direction.
>
> [Patches against drm-intel-nightly tree fetched 11/09/2014]
>
> John Harrison (21):
>    Bug: missing i915_seqno_passed() call?
>    drm/i915: Remove redundant parameter to i915_gem_object_wait_rendering__tail()
>    drm/i915: Ensure OLS & PLR are always in sync
>    drm/i915: Add reference count to request structure
>    drm/i915: Add helper functions to aid seqno -> request transition
>    drm/i915: Replace last_[rwf]_seqno with last_[rwf]_req
>    drm/i915: Ensure requests stick around during waits
>    drm/i915: Remove 'outstanding_lazy_seqno'
>    drm/i915: Make 'i915_gem_check_olr' actually check by request not seqno
>    drm/i915: Convert 'last_flip_req' to be a request not a seqno
>    drm/i915: Convert i915_wait_seqno to i915_wait_request
>    drm/i915: Convert 'i915_add_request' to take a request not a seqno
>    drm/i915: Convert mmio_flip::seqno to struct request
>    drm/i915: Convert 'flip_queued_seqno' into 'flip_queued_request'
>    drm/i915: Convert most 'i915_seqno_passed' calls into 'i915_gem_request_completed'
>    drm/i915: Convert __wait_seqno() to __wait_request()
>    drm/i915: Convert trace functions from seqno to request
>    drm/i915: Convert 'trace_irq' to use requests rather than seqnos
>    drm/i915: Convert semaphores to handle requests not seqnos
>    drm/i915: Convert 'ring_idle()' to use requests not seqnos
>    drm/i915: Remove 'obj->ring'
>
>   drivers/gpu/drm/i915/i915_debugfs.c        |   23 +--
>   drivers/gpu/drm/i915/i915_drv.h            |   64 +++++--
>   drivers/gpu/drm/i915/i915_gem.c            |  265 ++++++++++++++--------------
>   drivers/gpu/drm/i915/i915_gem_context.c    |   12 +-
>   drivers/gpu/drm/i915/i915_gem_execbuffer.c |    8 +-
>   drivers/gpu/drm/i915/i915_gem_gtt.h        |    4 +-
>   drivers/gpu/drm/i915/i915_gem_tiling.c     |    2 +-
>   drivers/gpu/drm/i915/i915_gpu_error.c      |   19 +-
>   drivers/gpu/drm/i915/i915_irq.c            |   12 +-
>   drivers/gpu/drm/i915/i915_trace.h          |   47 ++---
>   drivers/gpu/drm/i915/intel_display.c       |   47 ++---
>   drivers/gpu/drm/i915/intel_drv.h           |    4 +-
>   drivers/gpu/drm/i915/intel_lrc.c           |   49 ++---
>   drivers/gpu/drm/i915/intel_overlay.c       |   17 +-
>   drivers/gpu/drm/i915/intel_ringbuffer.c    |   88 +++++----
>   drivers/gpu/drm/i915/intel_ringbuffer.h    |   24 ++-
>   16 files changed, 392 insertions(+), 293 deletions(-)
>


[-- Attachment #1.2: Type: text/html, Size: 6904 bytes --]

[-- Attachment #2: Type: text/plain, Size: 159 bytes --]

_______________________________________________
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Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [RFC 02/21] drm/i915: Remove redundant parameter to i915_gem_object_wait_rendering__tail()

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:06PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>

Empty commit messages are a bit too thin. E.g. in this case this was an
oversight from

commit c8725f3dc0911d4354315a65150aecd8b7d0d74a
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Mar 17 12:21:55 2014 +0000

    drm/i915: Do not call retire_requests from wait_for_rendering

which means your patch here really should have Cc'ed patch author and
revierer (i.e. Chris & Brad) of the offending patch, too.

Especially in GEM where some of the interactions are _really_ tricky you
can't just remove code that looks funky. You really have to dig into the
history and find solid evidence that this is really just an oversight and
not something deeper.

> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com

Youre sob line isn't quite up to spec, it should have a full name + mail
address (like the From: line git send-email inserted).
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_gem.c |    7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 8c68219..aa2d882 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -1281,8 +1281,7 @@ i915_wait_seqno(struct intel_engine_cs *ring, uint32_t seqno)
>  }
>  
>  static int
> -i915_gem_object_wait_rendering__tail(struct drm_i915_gem_object *obj,
> -				     struct intel_engine_cs *ring)
> +i915_gem_object_wait_rendering__tail(struct drm_i915_gem_object *obj)
>  {
>  	if (!obj->active)
>  		return 0;
> @@ -1319,7 +1318,7 @@ i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj,
>  	if (ret)
>  		return ret;
>  
> -	return i915_gem_object_wait_rendering__tail(obj, ring);
> +	return i915_gem_object_wait_rendering__tail(obj);
>  }
>  
>  /* A nonblocking variant of the above wait. This is a highly dangerous routine
> @@ -1359,7 +1358,7 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
>  	if (ret)
>  		return ret;
>  
> -	return i915_gem_object_wait_rendering__tail(obj, ring);
> +	return i915_gem_object_wait_rendering__tail(obj);
>  }
>  
>  /**
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 03/21] drm/i915: Ensure OLS & PLR are always in sync

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:07PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> The new seqno alloction code pre-allocates a 'lazy' request structure and then
> tries to allocate the 'lazy' seqno. The seqno allocation can potential wrap
> around zero and when doing so, tries to idle the ring by waiting for all
> oustanding work to complete. With a scheduler in place, this can mean first
> submitting extra work to the ring. However, at this point in time, the lazy
> request is valid but the lazy seqno is not. Some existing code was getting
> confused by this state and Bad Things would happen.

I'm confused about this description. I think you need to go into more
detail about what exactly you mean with "new seqno allocation code" (does
this reference some future patches), "confused state" and "Bad Things".

I get a bit the impression that this is just a bad interaction between the
scheduler and the seqno wrapping. Which might be due to allocating the
seqno too early when the scheduler it active. So if that's the case then
imo this shouldn't be in the s/seqno/request/ prep work series.

> The safest solution is to still allocate the lazy request in advance (to avoid
> having to roll back in an out of memory sitation) but to save the pointer in a
> local variable rather than immediately updating the lazy pointer. Only after a
> valid seqno has been acquired is the lazy request pointer actually updated.
> 
> This guarantees that both lazy values are either invalid or both valid. There
> can no longer be an inconsistent state.
> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com
> ---
>  drivers/gpu/drm/i915/intel_lrc.c        |   42 ++++++++++++++++++++-----------
>  drivers/gpu/drm/i915/intel_ringbuffer.c |   29 +++++++++++++++------
>  2 files changed, 48 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index bafd38b..3ac2622 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -796,27 +796,39 @@ void intel_logical_ring_advance_and_submit(struct intel_ringbuffer *ringbuf)
>  static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
>  				    struct intel_context *ctx)
>  {
> -	if (ring->outstanding_lazy_seqno)
> -		return 0;
> +	struct drm_i915_gem_request *request;
> +	int ret;
>  
> -	if (ring->preallocated_lazy_request == NULL) {
> -		struct drm_i915_gem_request *request;
> +	/* The aim is to replace seqno values with request structures. A step
> +	 * along the way is to switch to using the PLR in preference to the
> +	 * OLS. That requires the PLR to only be valid when the OLS is also
> +	 * valid. I.e., the two must be kept in step. */
>  
> -		request = kmalloc(sizeof(*request), GFP_KERNEL);
> -		if (request == NULL)
> -			return -ENOMEM;
> +	if (ring->outstanding_lazy_seqno) {
> +		BUG_ON(ring->preallocated_lazy_request == NULL);

Too many BUG_ON in this patch. This one here can easily be avoided with a
if (WARN_ON) retrun -EIO; or so, the below one would just indicate a leak
so a plain WARN_ON is good enough.

BUG_ON makes it a major pain to debug anything out there in the field, so
the barrier to acceptance is really high.

> +		return 0;
> +	}
> +	BUG_ON(ring->preallocated_lazy_request != NULL);
>  
> -		/* Hold a reference to the context this request belongs to
> -		 * (we will need it when the time comes to emit/retire the
> -		 * request).
> -		 */
> -		request->ctx = ctx;
> -		i915_gem_context_reference(request->ctx);
> +	request = kmalloc(sizeof(*request), GFP_KERNEL);
> +	if (request == NULL)
> +		return -ENOMEM;
>  
> -		ring->preallocated_lazy_request = request;
> +	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
> +	if (ret) {
> +		kfree(request);
> +		return ret;
>  	}
>  
> -	return i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
> +	/* Hold a reference to the context this request belongs to
> +	 * (we will need it when the time comes to emit/retire the
> +	 * request).
> +	 */
> +	request->ctx = ctx;
> +	i915_gem_context_reference(request->ctx);
> +
> +	ring->preallocated_lazy_request = request;
> +	return 0;
>  }
>  
>  static int logical_ring_wait_request(struct intel_ringbuffer *ringbuf,
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 25795f2..cceac67 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -2000,20 +2000,33 @@ int intel_ring_idle(struct intel_engine_cs *ring)
>  static int
>  intel_ring_alloc_seqno(struct intel_engine_cs *ring)
>  {
> -	if (ring->outstanding_lazy_seqno)
> +	int ret;
> +	struct drm_i915_gem_request *request;
> +
> +	/* The aim is to replace seqno values with request structures. A step
> +	 * along the way is to switch to using the PLR in preference to the
> +	 * OLS. That requires the PLR to only be valid when the OLS is also
> +	 * valid. I.e., the two must be kept in step. */
> +
> +	if (ring->outstanding_lazy_seqno) {
> +		BUG_ON(ring->preallocated_lazy_request == NULL);
>  		return 0;
> +	}
>  
> -	if (ring->preallocated_lazy_request == NULL) {
> -		struct drm_i915_gem_request *request;
> +	BUG_ON(ring->preallocated_lazy_request != NULL);
>  
> -		request = kmalloc(sizeof(*request), GFP_KERNEL);
> -		if (request == NULL)
> -			return -ENOMEM;
> +	request = kmalloc(sizeof(*request), GFP_KERNEL);
> +	if (request == NULL)
> +		return -ENOMEM;
>  
> -		ring->preallocated_lazy_request = request;
> +	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
> +	if (ret) {
> +		kfree(request);
> +		return ret;
>  	}
>  
> -	return i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
> +	ring->preallocated_lazy_request = request;
> +	return 0;
>  }
>  
>  static int __intel_ring_prepare(struct intel_engine_cs *ring,
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 05/21] drm/i915: Add helper functions to aid seqno -> request transition

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:09PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 

I think a few words about how these helpers help the transitions (and
example maybe) would be great. Since without peeking ahead (which I
didn't) and looking at the JIRA (which I've forgotten all about already
right after writing it) this doesn't make a lot of sense ;-)

> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com
> ---
>  drivers/gpu/drm/i915/i915_drv.h         |   12 ++++++++++++
>  drivers/gpu/drm/i915/intel_ringbuffer.h |    7 +++++++
>  2 files changed, 19 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index e1858e7..62c9f66 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1946,6 +1946,18 @@ struct drm_i915_gem_request {
>  
>  void i915_gem_request_free(struct kref *req_ref);
>  
> +static inline uint32_t
> +i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
> +{
> +	return req ? req->seqno : 0;
> +}
> +
> +static inline struct intel_engine_cs *
> +i915_gem_request_get_ring(struct drm_i915_gem_request *req)
> +{
> +	return req ? req->ring : NULL;
> +}
> +
>  static inline void
>  i915_gem_request_reference(struct drm_i915_gem_request *req)
>  {
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
> index 96479c8..cc1b62f 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
> @@ -435,6 +435,13 @@ static inline u32 intel_ring_get_seqno(struct intel_engine_cs *ring)
>  	return ring->outstanding_lazy_seqno;
>  }
>  
> +static inline struct drm_i915_gem_request *
> +intel_ring_get_request(struct intel_engine_cs *ring)
> +{
> +	BUG_ON(ring->preallocated_lazy_request == NULL);

Again, I'm not a fan of BUG_ON. But if this is just a transitional thing
and will disappear at the end of the series I'm ok with it.
-Daniel

> +	return ring->preallocated_lazy_request;
> +}
> +
>  static inline void i915_trace_irq_get(struct intel_engine_cs *ring, u32 seqno)
>  {
>  	if (ring->trace_irq_seqno == 0 && ring->irq_get(ring))
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 06/21] drm/i915: Replace last_[rwf]_seqno with last_[rwf]_req

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:10PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c        |    6 +--
>  drivers/gpu/drm/i915/i915_drv.h            |    6 +--
>  drivers/gpu/drm/i915/i915_gem.c            |   66 ++++++++++++++++------------
>  drivers/gpu/drm/i915/i915_gem_execbuffer.c |    6 +--
>  drivers/gpu/drm/i915/i915_gem_gtt.h        |    4 +-
>  drivers/gpu/drm/i915/i915_gem_tiling.c     |    2 +-
>  drivers/gpu/drm/i915/i915_gpu_error.c      |    4 +-
>  drivers/gpu/drm/i915/intel_display.c       |   10 ++---
>  drivers/gpu/drm/i915/intel_ringbuffer.h    |    2 +-
>  9 files changed, 58 insertions(+), 48 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 063b448..726a8f0 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -133,9 +133,9 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj)
>  		   obj->base.size / 1024,
>  		   obj->base.read_domains,
>  		   obj->base.write_domain,
> -		   obj->last_read_seqno,
> -		   obj->last_write_seqno,
> -		   obj->last_fenced_seqno,
> +		   i915_gem_request_get_seqno(obj->last_read_req),
> +		   i915_gem_request_get_seqno(obj->last_write_req),
> +		   i915_gem_request_get_seqno(obj->last_fenced_req),
>  		   i915_cache_level_str(to_i915(obj->base.dev), obj->cache_level),
>  		   obj->dirty ? " dirty" : "",
>  		   obj->madv == I915_MADV_DONTNEED ? " purgeable" : "");
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 62c9f66..1401266 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1862,10 +1862,10 @@ struct drm_i915_gem_object {
>  	struct intel_engine_cs *ring;
>  
>  	/** Breadcrumb of last rendering to the buffer. */
> -	uint32_t last_read_seqno;
> -	uint32_t last_write_seqno;
> +	struct drm_i915_gem_request *last_read_req;
> +	struct drm_i915_gem_request *last_write_req;
>  	/** Breadcrumb of last fenced GPU access to the buffer. */
> -	uint32_t last_fenced_seqno;
> +	struct drm_i915_gem_request *last_fenced_req;
>  
>  	/** Current tiling stride for the object, if it's tiled. */
>  	uint32_t stride;
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 2555cd8..2c33a83 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -1289,11 +1289,11 @@ i915_gem_object_wait_rendering__tail(struct drm_i915_gem_object *obj)
>  	/* Manually manage the write flush as we may have not yet
>  	 * retired the buffer.
>  	 *
> -	 * Note that the last_write_seqno is always the earlier of
> -	 * the two (read/write) seqno, so if we haved successfully waited,
> +	 * Note that the last_write_req is always the earlier of
> +	 * the two (read/write) requests, so if we haved successfully waited,
>  	 * we know we have passed the last write.
>  	 */
> -	obj->last_write_seqno = 0;
> +	obj->last_write_req = NULL;
>  
>  	return 0;
>  }
> @@ -1306,14 +1306,18 @@ static __must_check int
>  i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj,
>  			       bool readonly)
>  {
> +	struct drm_i915_gem_request *req;
>  	struct intel_engine_cs *ring = obj->ring;
>  	u32 seqno;
>  	int ret;
>  
> -	seqno = readonly ? obj->last_write_seqno : obj->last_read_seqno;
> -	if (seqno == 0)
> +	req = readonly ? obj->last_write_req : obj->last_read_req;
> +	if (!req)
>  		return 0;
>  
> +	seqno = i915_gem_request_get_seqno(req);
> +	BUG_ON(seqno == 0);

Again, you like BUG_ON a bit too much for my taste. If you want these
checks imo a WARN_ON in i915_gem_request_get_seqno (iff req != NULL ofc)
in the previous patch would be much better.
-Daniel

> +
>  	ret = i915_wait_seqno(ring, seqno);
>  	if (ret)
>  		return ret;
> @@ -1329,6 +1333,7 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
>  					    struct drm_i915_file_private *file_priv,
>  					    bool readonly)
>  {
> +	struct drm_i915_gem_request *req;
>  	struct drm_device *dev = obj->base.dev;
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  	struct intel_engine_cs *ring = obj->ring;
> @@ -1339,10 +1344,13 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
>  	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
>  	BUG_ON(!dev_priv->mm.interruptible);
>  
> -	seqno = readonly ? obj->last_write_seqno : obj->last_read_seqno;
> -	if (seqno == 0)
> +	req = readonly ? obj->last_write_req : obj->last_read_req;
> +	if (!req)
>  		return 0;
>  
> +	seqno = i915_gem_request_get_seqno(req);
> +	BUG_ON(seqno == 0);
> +
>  	ret = i915_gem_check_wedge(&dev_priv->gpu_error, true);
>  	if (ret)
>  		return ret;
> @@ -2180,12 +2188,12 @@ static void
>  i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
>  			       struct intel_engine_cs *ring)
>  {
> -	u32 seqno = intel_ring_get_seqno(ring);
> +	struct drm_i915_gem_request *req = intel_ring_get_request(ring);
>  
>  	BUG_ON(ring == NULL);
> -	if (obj->ring != ring && obj->last_write_seqno) {
> -		/* Keep the seqno relative to the current ring */
> -		obj->last_write_seqno = seqno;
> +	if (obj->ring != ring && obj->last_write_req) {
> +		/* Keep the request relative to the current ring */
> +		obj->last_write_req = req;
>  	}
>  	obj->ring = ring;
>  
> @@ -2197,7 +2205,7 @@ i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
>  
>  	list_move_tail(&obj->ring_list, &ring->active_list);
>  
> -	obj->last_read_seqno = seqno;
> +	obj->last_read_req = req;
>  }
>  
>  void i915_vma_move_to_active(struct i915_vma *vma,
> @@ -2228,11 +2236,11 @@ i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
>  	list_del_init(&obj->ring_list);
>  	obj->ring = NULL;
>  
> -	obj->last_read_seqno = 0;
> -	obj->last_write_seqno = 0;
> +	obj->last_read_req = NULL;
> +	obj->last_write_req = NULL;
>  	obj->base.write_domain = 0;
>  
> -	obj->last_fenced_seqno = 0;
> +	obj->last_fenced_req = NULL;
>  
>  	obj->active = 0;
>  	drm_gem_object_unreference(&obj->base);
> @@ -2249,7 +2257,7 @@ i915_gem_object_retire(struct drm_i915_gem_object *obj)
>  		return;
>  
>  	if (i915_seqno_passed(ring->get_seqno(ring, true),
> -			      obj->last_read_seqno))
> +			      i915_gem_request_get_seqno(obj->last_read_req)))
>  		i915_gem_object_move_to_inactive(obj);
>  }
>  
> @@ -2669,7 +2677,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
>  				      struct drm_i915_gem_object,
>  				      ring_list);
>  
> -		if (!i915_seqno_passed(seqno, obj->last_read_seqno))
> +		if (!i915_seqno_passed(seqno, i915_gem_request_get_seqno(obj->last_read_req)))
>  			break;
>  
>  		i915_gem_object_move_to_inactive(obj);
> @@ -2779,7 +2787,7 @@ i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
>  	int ret;
>  
>  	if (obj->active) {
> -		ret = i915_gem_check_olr(obj->ring, obj->last_read_seqno);
> +		ret = i915_gem_check_olr(obj->ring, i915_gem_request_get_seqno(obj->last_read_req));
>  		if (ret)
>  			return ret;
>  
> @@ -2838,13 +2846,14 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
>  		goto out;
>  
>  	if (obj->active) {
> -		seqno = obj->last_read_seqno;
> +		if (!obj->last_read_req)
> +			goto out;
> +
> +		seqno = i915_gem_request_get_seqno(obj->last_read_req);
> +		BUG_ON(seqno == 0);
>  		ring = obj->ring;
>  	}
>  
> -	if (seqno == 0)
> -		 goto out;
> -
>  	/* Do this after OLR check to make sure we make forward progress polling
>  	 * on this IOCTL with a timeout <=0 (like busy ioctl)
>  	 */
> @@ -2894,7 +2903,7 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
>  
>  	idx = intel_ring_sync_index(from, to);
>  
> -	seqno = obj->last_read_seqno;
> +	seqno = i915_gem_request_get_seqno(obj->last_read_req);
>  	/* Optimization: Avoid semaphore sync when we are sure we already
>  	 * waited for an object with higher seqno */
>  	if (seqno <= from->semaphore.sync_seqno[idx]) /* <--- broken?! needs to use i915_seqno_passed()??? */
> @@ -2907,11 +2916,12 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
>  	trace_i915_gem_ring_sync_to(from, to, seqno);
>  	ret = to->semaphore.sync_to(to, from, seqno);
>  	if (!ret)
> -		/* We use last_read_seqno because sync_to()
> +		/* We use last_read_req because sync_to()
>  		 * might have just caused seqno wrap under
>  		 * the radar.
>  		 */
> -		from->semaphore.sync_seqno[idx] = obj->last_read_seqno;
> +		from->semaphore.sync_seqno[idx] =
> +				i915_gem_request_get_seqno(obj->last_read_req);
>  
>  	return ret;
>  }
> @@ -3224,12 +3234,12 @@ static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
>  static int
>  i915_gem_object_wait_fence(struct drm_i915_gem_object *obj)
>  {
> -	if (obj->last_fenced_seqno) {
> -		int ret = i915_wait_seqno(obj->ring, obj->last_fenced_seqno);
> +	if (obj->last_fenced_req) {
> +		int ret = i915_wait_seqno(obj->ring, i915_gem_request_get_seqno(obj->last_fenced_req));
>  		if (ret)
>  			return ret;
>  
> -		obj->last_fenced_seqno = 0;
> +		obj->last_fenced_req = NULL;
>  	}
>  
>  	return 0;
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index 1a0611b..4250211 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -946,7 +946,7 @@ void
>  i915_gem_execbuffer_move_to_active(struct list_head *vmas,
>  				   struct intel_engine_cs *ring)
>  {
> -	u32 seqno = intel_ring_get_seqno(ring);
> +	struct drm_i915_gem_request *req = intel_ring_get_request(ring);
>  	struct i915_vma *vma;
>  
>  	list_for_each_entry(vma, vmas, exec_list) {
> @@ -963,7 +963,7 @@ i915_gem_execbuffer_move_to_active(struct list_head *vmas,
>  		i915_vma_move_to_active(vma, ring);
>  		if (obj->base.write_domain) {
>  			obj->dirty = 1;
> -			obj->last_write_seqno = seqno;
> +			obj->last_write_req = req;
>  
>  			intel_fb_obj_invalidate(obj, ring);
>  
> @@ -971,7 +971,7 @@ i915_gem_execbuffer_move_to_active(struct list_head *vmas,
>  			obj->base.write_domain &= ~I915_GEM_GPU_DOMAINS;
>  		}
>  		if (entry->flags & EXEC_OBJECT_NEEDS_FENCE) {
> -			obj->last_fenced_seqno = seqno;
> +			obj->last_fenced_req = req;
>  			if (entry->flags & __EXEC_OBJECT_HAS_FENCE) {
>  				struct drm_i915_private *dev_priv = to_i915(ring->dev);
>  				list_move_tail(&dev_priv->fence_regs[obj->fence_reg].lru_list,
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
> index d5c14af..8a220c0 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.h
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
> @@ -178,7 +178,7 @@ struct i915_address_space {
>  	 * List of objects currently involved in rendering.
>  	 *
>  	 * Includes buffers having the contents of their GPU caches
> -	 * flushed, not necessarily primitives.  last_rendering_seqno
> +	 * flushed, not necessarily primitives.  last_rendering_req
>  	 * represents when the rendering involved will be completed.
>  	 *
>  	 * A reference is held on the buffer while on this list.
> @@ -189,7 +189,7 @@ struct i915_address_space {
>  	 * LRU list of objects which are not in the ringbuffer and
>  	 * are ready to unbind, but are still in the GTT.
>  	 *
> -	 * last_rendering_seqno is 0 while an object is in this list.
> +	 * last_rendering_req is NULL while an object is in this list.
>  	 *
>  	 * A reference is not held on the buffer while on this list,
>  	 * as merely being GTT-bound shouldn't prevent its being
> diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
> index 2cefb59..fa5fc8c 100644
> --- a/drivers/gpu/drm/i915/i915_gem_tiling.c
> +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
> @@ -383,7 +383,7 @@ i915_gem_set_tiling(struct drm_device *dev, void *data,
>  
>  		if (ret == 0) {
>  			obj->fence_dirty =
> -				obj->last_fenced_seqno ||
> +				obj->last_fenced_req ||
>  				obj->fence_reg != I915_FENCE_REG_NONE;
>  
>  			obj->tiling_mode = args->tiling_mode;
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index 2c87a79..1b58390 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -666,8 +666,8 @@ static void capture_bo(struct drm_i915_error_buffer *err,
>  
>  	err->size = obj->base.size;
>  	err->name = obj->base.name;
> -	err->rseqno = obj->last_read_seqno;
> -	err->wseqno = obj->last_write_seqno;
> +	err->rseqno = i915_gem_request_get_seqno(obj->last_read_req);
> +	err->wseqno = i915_gem_request_get_seqno(obj->last_write_req);
>  	err->gtt_offset = vma->node.start;
>  	err->read_domains = obj->base.read_domains;
>  	err->write_domain = obj->base.write_domain;
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index b78f00a..5aae3d1e 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -9766,16 +9766,16 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
>  
>  	lockdep_assert_held(&obj->base.dev->struct_mutex);
>  
> -	if (!obj->last_write_seqno)
> +	if (!obj->last_write_req)
>  		return 0;
>  
>  	ring = obj->ring;
>  
>  	if (i915_seqno_passed(ring->get_seqno(ring, true),
> -			      obj->last_write_seqno))
> +			      i915_gem_request_get_seqno(obj->last_write_req)))
>  		return 0;
>  
> -	ret = i915_gem_check_olr(ring, obj->last_write_seqno);
> +	ret = i915_gem_check_olr(ring, i915_gem_request_get_seqno(obj->last_write_req));
>  	if (ret)
>  		return ret;
>  
> @@ -9838,7 +9838,7 @@ static int intel_queue_mmio_flip(struct drm_device *dev,
>  	}
>  
>  	spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
> -	intel_crtc->mmio_flip.seqno = obj->last_write_seqno;
> +	intel_crtc->mmio_flip.seqno = i915_gem_request_get_seqno(obj->last_write_req);
>  	intel_crtc->mmio_flip.ring_id = obj->ring->id;
>  	spin_unlock_irqrestore(&dev_priv->mmio_flip_lock, irq_flags);
>  
> @@ -10045,7 +10045,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  		if (ret)
>  			goto cleanup_unpin;
>  
> -		work->flip_queued_seqno = obj->last_write_seqno;
> +		work->flip_queued_seqno = i915_gem_request_get_seqno(obj->last_write_req);
>  		work->flip_queued_ring = obj->ring;
>  	} else {
>  		ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, ring,
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
> index cc1b62f..d98b964 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
> @@ -249,7 +249,7 @@ struct  intel_engine_cs {
>  	 * ringbuffer.
>  	 *
>  	 * Includes buffers having the contents of their GPU caches
> -	 * flushed, not necessarily primitives.  last_rendering_seqno
> +	 * flushed, not necessarily primitives.  last_rendering_req
>  	 * represents when the rendering involved will be completed.
>  	 *
>  	 * A reference is held on the buffer while on this list.
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 08/21] drm/i915: Remove 'outstanding_lazy_seqno'

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:12PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com

given the scary commit message for patch 3 I'm confused that we can just
do this. Or maybe we should move patch 3 right before this one here and
instead of mentioning fun in combination with the scheduler as the
justification use this patch here. Since obviously if we dig out the ols
from the plr then they obviously need to be allocated together.

In any case this patch here should at least mention why this is suddenly
possible without fuzz. A few comments below.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_gem.c            |   13 +++-----
>  drivers/gpu/drm/i915/i915_gem_execbuffer.c |    2 +-
>  drivers/gpu/drm/i915/intel_display.c       |    2 +-
>  drivers/gpu/drm/i915/intel_lrc.c           |   20 ++++--------
>  drivers/gpu/drm/i915/intel_ringbuffer.c    |   48 +++++++++++++++-------------
>  drivers/gpu/drm/i915/intel_ringbuffer.h    |   13 ++------
>  6 files changed, 41 insertions(+), 57 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 53b48ad..0d0eb26 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -1108,7 +1108,7 @@ i915_gem_check_olr(struct intel_engine_cs *ring, u32 seqno)
>  	BUG_ON(!mutex_is_locked(&ring->dev->struct_mutex));
>  
>  	ret = 0;
> -	if (seqno == ring->outstanding_lazy_seqno)
> +	if (seqno == i915_gem_request_get_seqno(ring->outstanding_lazy_request))
>  		ret = i915_add_request(ring, NULL);
>  
>  	return ret;
> @@ -2344,7 +2344,7 @@ int __i915_add_request(struct intel_engine_cs *ring,
>  	u32 request_ring_position, request_start;
>  	int ret;
>  
> -	request = ring->preallocated_lazy_request;
> +	request = ring->outstanding_lazy_request;
>  	if (WARN_ON(request == NULL))
>  		return -ENOMEM;
>  
> @@ -2391,7 +2391,6 @@ int __i915_add_request(struct intel_engine_cs *ring,
>  
>  	i915_gem_request_reference(request);
>  
> -	request->seqno = intel_ring_get_seqno(ring);
>  	request->ring = ring;
>  	request->head = request_start;
>  	request->tail = request_ring_position;
> @@ -2428,8 +2427,7 @@ int __i915_add_request(struct intel_engine_cs *ring,
>  	}
>  
>  	trace_i915_gem_request_add(ring, request->seqno);
> -	ring->outstanding_lazy_seqno = 0;
> -	ring->preallocated_lazy_request = NULL;
> +	ring->outstanding_lazy_request = NULL;
>  
>  	if (!dev_priv->ums.mm_suspended) {
>  		i915_queue_hangcheck(ring->dev);
> @@ -2605,9 +2603,8 @@ static void i915_gem_reset_ring_cleanup(struct drm_i915_private *dev_priv,
>  	}
>  
>  	/* These may not have been flush before the reset, do so now */
> -	kfree(ring->preallocated_lazy_request);
> -	ring->preallocated_lazy_request = NULL;
> -	ring->outstanding_lazy_seqno = 0;
> +	kfree(ring->outstanding_lazy_request);
> +	ring->outstanding_lazy_request = NULL;

Somewhat unrelated, but shouldn't we move to refcount even the ring->plr?
If we allocate it then the ring->plr pointer would hold the ref, then it
gets transferred to the request list.

This isn't too terribly important yet, but sometimes (when we have
per-engine reset) we need to fix up all the request access the hangcheck
and error state capture code does. Which probably means we really need to
refcount requests super-carefully everywhere (because the hangcheck can
happen almost anywhere at all).

>  }
>  
>  void i915_gem_restore_fences(struct drm_device *dev)
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index 4250211..e0fdfae 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -1170,7 +1170,7 @@ i915_gem_ringbuffer_submission(struct drm_device *dev, struct drm_file *file,
>  			return ret;
>  	}
>  
> -	trace_i915_gem_ring_dispatch(ring, intel_ring_get_seqno(ring), flags);
> +	trace_i915_gem_ring_dispatch(ring, i915_gem_request_get_seqno(intel_ring_get_request(ring)), flags);
>  
>  	i915_gem_execbuffer_move_to_active(vmas, ring);
>  	i915_gem_execbuffer_retire_commands(dev, file, ring, batch_obj);
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 5aae3d1e..6da18c5 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -10053,7 +10053,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  		if (ret)
>  			goto cleanup_unpin;
>  
> -		work->flip_queued_seqno = intel_ring_get_seqno(ring);
> +		work->flip_queued_seqno = i915_gem_request_get_seqno(intel_ring_get_request(ring));
>  		work->flip_queued_ring = ring;
>  	}
>  
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index b5b6430..7005745 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -799,16 +799,8 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
>  	struct drm_i915_gem_request *request;
>  	int ret;
>  
> -	/* The aim is to replace seqno values with request structures. A step
> -	 * along the way is to switch to using the PLR in preference to the
> -	 * OLS. That requires the PLR to only be valid when the OLS is also
> -	 * valid. I.e., the two must be kept in step. */

If you add a comment only to remove it later on in the series I usually
smash an "XXX: This will get cleaned up further" or similar on top of it.
it aids review if you can gauge this whitout peeking ahead.

> -
> -	if (ring->outstanding_lazy_seqno) {
> -		BUG_ON(ring->preallocated_lazy_request == NULL);
> +	if (ring->outstanding_lazy_request)
>  		return 0;
> -	}
> -	BUG_ON(ring->preallocated_lazy_request != NULL);
>  
>  	request = kmalloc(sizeof(*request), GFP_KERNEL);
>  	if (request == NULL)
> @@ -816,7 +808,7 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
>  
>  	kref_init(&request->ref);
>  
> -	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
> +	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
>  	if (ret) {
>  		kfree(request);
>  		return ret;
> @@ -829,7 +821,7 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
>  	request->ctx = ctx;
>  	i915_gem_context_reference(request->ctx);
>  
> -	ring->preallocated_lazy_request = request;
> +	ring->outstanding_lazy_request = request;
>  	return 0;
>  }
>  
> @@ -1212,7 +1204,8 @@ static int gen8_emit_request(struct intel_ringbuffer *ringbuf)
>  				(ring->status_page.gfx_addr +
>  				(I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT)));
>  	intel_logical_ring_emit(ringbuf, 0);
> -	intel_logical_ring_emit(ringbuf, ring->outstanding_lazy_seqno);
> +	intel_logical_ring_emit(ringbuf,
> +		i915_gem_request_get_seqno(ring->outstanding_lazy_request));
>  	intel_logical_ring_emit(ringbuf, MI_USER_INTERRUPT);
>  	intel_logical_ring_emit(ringbuf, MI_NOOP);
>  	intel_logical_ring_advance_and_submit(ringbuf);
> @@ -1235,8 +1228,7 @@ void intel_logical_ring_cleanup(struct intel_engine_cs *ring)
>  
>  	intel_logical_ring_stop(ring);
>  	WARN_ON((I915_READ_MODE(ring) & MODE_IDLE) == 0);
> -	ring->preallocated_lazy_request = NULL;
> -	ring->outstanding_lazy_seqno = 0;
> +	ring->outstanding_lazy_request = NULL;
>  
>  	if (ring->cleanup)
>  		ring->cleanup(ring);
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 7350f78..dd59691 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -895,17 +895,20 @@ static int gen8_rcs_signal(struct intel_engine_cs *signaller,
>  		return ret;
>  
>  	for_each_ring(waiter, dev_priv, i) {
> +		u32 seqno;
>  		u64 gtt_offset = signaller->semaphore.signal_ggtt[i];
>  		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
>  			continue;
>  
> +		seqno = i915_gem_request_get_seqno(
> +					   signaller->outstanding_lazy_request);
>  		intel_ring_emit(signaller, GFX_OP_PIPE_CONTROL(6));
>  		intel_ring_emit(signaller, PIPE_CONTROL_GLOBAL_GTT_IVB |
>  					   PIPE_CONTROL_QW_WRITE |
>  					   PIPE_CONTROL_FLUSH_ENABLE);
>  		intel_ring_emit(signaller, lower_32_bits(gtt_offset));
>  		intel_ring_emit(signaller, upper_32_bits(gtt_offset));
> -		intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
> +		intel_ring_emit(signaller, seqno);
>  		intel_ring_emit(signaller, 0);
>  		intel_ring_emit(signaller, MI_SEMAPHORE_SIGNAL |
>  					   MI_SEMAPHORE_TARGET(waiter->id));
> @@ -933,16 +936,19 @@ static int gen8_xcs_signal(struct intel_engine_cs *signaller,
>  		return ret;
>  
>  	for_each_ring(waiter, dev_priv, i) {
> +		u32 seqno;
>  		u64 gtt_offset = signaller->semaphore.signal_ggtt[i];
>  		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
>  			continue;
>  
> +		seqno = i915_gem_request_get_seqno(
> +					   signaller->outstanding_lazy_request);
>  		intel_ring_emit(signaller, (MI_FLUSH_DW + 1) |
>  					   MI_FLUSH_DW_OP_STOREDW);
>  		intel_ring_emit(signaller, lower_32_bits(gtt_offset) |
>  					   MI_FLUSH_DW_USE_GTT);
>  		intel_ring_emit(signaller, upper_32_bits(gtt_offset));
> -		intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
> +		intel_ring_emit(signaller, seqno);
>  		intel_ring_emit(signaller, MI_SEMAPHORE_SIGNAL |
>  					   MI_SEMAPHORE_TARGET(waiter->id));
>  		intel_ring_emit(signaller, 0);
> @@ -971,9 +977,11 @@ static int gen6_signal(struct intel_engine_cs *signaller,
>  	for_each_ring(useless, dev_priv, i) {
>  		u32 mbox_reg = signaller->semaphore.mbox.signal[i];
>  		if (mbox_reg != GEN6_NOSYNC) {
> +			u32 seqno = i915_gem_request_get_seqno(
> +					   signaller->outstanding_lazy_request);
>  			intel_ring_emit(signaller, MI_LOAD_REGISTER_IMM(1));
>  			intel_ring_emit(signaller, mbox_reg);
> -			intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
> +			intel_ring_emit(signaller, seqno);
>  		}
>  	}
>  
> @@ -1008,7 +1016,8 @@ gen6_add_request(struct intel_engine_cs *ring)
>  
>  	intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
>  	intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
> -	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
> +	intel_ring_emit(ring,
> +		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
>  	intel_ring_emit(ring, MI_USER_INTERRUPT);
>  	__intel_ring_advance(ring);
>  
> @@ -1126,7 +1135,8 @@ pc_render_add_request(struct intel_engine_cs *ring)
>  			PIPE_CONTROL_WRITE_FLUSH |
>  			PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE);
>  	intel_ring_emit(ring, ring->scratch.gtt_offset | PIPE_CONTROL_GLOBAL_GTT);
> -	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
> +	intel_ring_emit(ring,
> +		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
>  	intel_ring_emit(ring, 0);
>  	PIPE_CONTROL_FLUSH(ring, scratch_addr);
>  	scratch_addr += 2 * CACHELINE_BYTES; /* write to separate cachelines */
> @@ -1145,7 +1155,8 @@ pc_render_add_request(struct intel_engine_cs *ring)
>  			PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE |
>  			PIPE_CONTROL_NOTIFY);
>  	intel_ring_emit(ring, ring->scratch.gtt_offset | PIPE_CONTROL_GLOBAL_GTT);
> -	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
> +	intel_ring_emit(ring,
> +		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
>  	intel_ring_emit(ring, 0);
>  	__intel_ring_advance(ring);
>  
> @@ -1385,7 +1396,8 @@ i9xx_add_request(struct intel_engine_cs *ring)
>  
>  	intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
>  	intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
> -	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
> +	intel_ring_emit(ring,
> +		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
>  	intel_ring_emit(ring, MI_USER_INTERRUPT);
>  	__intel_ring_advance(ring);
>  
> @@ -1839,8 +1851,7 @@ void intel_cleanup_ring_buffer(struct intel_engine_cs *ring)
>  	WARN_ON(!IS_GEN2(ring->dev) && (I915_READ_MODE(ring) & MODE_IDLE) == 0);
>  
>  	intel_destroy_ringbuffer_obj(ringbuf);
> -	ring->preallocated_lazy_request = NULL;
> -	ring->outstanding_lazy_seqno = 0;
> +	ring->outstanding_lazy_request = NULL;
>  
>  	if (ring->cleanup)
>  		ring->cleanup(ring);
> @@ -1980,7 +1991,7 @@ int intel_ring_idle(struct intel_engine_cs *ring)
>  	int ret;
>  
>  	/* We need to add any requests required to flush the objects and ring */
> -	if (ring->outstanding_lazy_seqno) {
> +	if (ring->outstanding_lazy_request) {
>  		ret = i915_add_request(ring, NULL);
>  		if (ret)
>  			return ret;
> @@ -2003,17 +2014,8 @@ intel_ring_alloc_seqno(struct intel_engine_cs *ring)
>  	int ret;
>  	struct drm_i915_gem_request *request;
>  
> -	/* The aim is to replace seqno values with request structures. A step
> -	 * along the way is to switch to using the PLR in preference to the
> -	 * OLS. That requires the PLR to only be valid when the OLS is also
> -	 * valid. I.e., the two must be kept in step. */
> -
> -	if (ring->outstanding_lazy_seqno) {
> -		BUG_ON(ring->preallocated_lazy_request == NULL);
> +	if (ring->outstanding_lazy_request)
>  		return 0;
> -	}
> -
> -	BUG_ON(ring->preallocated_lazy_request != NULL);
>  
>  	request = kmalloc(sizeof(*request), GFP_KERNEL);
>  	if (request == NULL)
> @@ -2021,13 +2023,13 @@ intel_ring_alloc_seqno(struct intel_engine_cs *ring)
>  
>  	kref_init(&request->ref);
>  
> -	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
> +	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
>  	if (ret) {
>  		kfree(request);
>  		return ret;
>  	}
>  
> -	ring->preallocated_lazy_request = request;
> +	ring->outstanding_lazy_request = request;
>  	return 0;
>  }
>  
> @@ -2103,7 +2105,7 @@ void intel_ring_init_seqno(struct intel_engine_cs *ring, u32 seqno)
>  	struct drm_device *dev = ring->dev;
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  
> -	BUG_ON(ring->outstanding_lazy_seqno);
> +	BUG_ON(ring->outstanding_lazy_request);
>  
>  	if (INTEL_INFO(dev)->gen == 6 || INTEL_INFO(dev)->gen == 7) {
>  		I915_WRITE(RING_SYNC_0(ring->mmio_base), 0);
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
> index d98b964..98b219d 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
> @@ -265,8 +265,7 @@ struct  intel_engine_cs {
>  	/**
>  	 * Do we have some not yet emitted requests outstanding?
>  	 */
> -	struct drm_i915_gem_request *preallocated_lazy_request;
> -	u32 outstanding_lazy_seqno;
> +	struct drm_i915_gem_request *outstanding_lazy_request;
>  	bool gpu_caches_dirty;
>  	bool fbc_dirty;
>  
> @@ -429,17 +428,11 @@ static inline u32 intel_ring_get_tail(struct intel_ringbuffer *ringbuf)
>  	return ringbuf->tail;
>  }
>  
> -static inline u32 intel_ring_get_seqno(struct intel_engine_cs *ring)
> -{
> -	BUG_ON(ring->outstanding_lazy_seqno == 0);
> -	return ring->outstanding_lazy_seqno;
> -}
> -
>  static inline struct drm_i915_gem_request *
>  intel_ring_get_request(struct intel_engine_cs *ring)
>  {
> -	BUG_ON(ring->preallocated_lazy_request == NULL);
> -	return ring->preallocated_lazy_request;
> +	BUG_ON(ring->outstanding_lazy_request == NULL);
> +	return ring->outstanding_lazy_request;
>  }
>  
>  static inline void i915_trace_irq_get(struct intel_engine_cs *ring, u32 seqno)
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 08/21] drm/i915: Remove 'outstanding_lazy_seqno'

[Daniel Vetter]

On Sun, Oct 19, 2014 at 2:48 PM, Daniel Vetter <daniel@ffwll.ch> wrote:
>> @@ -2605,9 +2603,8 @@ static void i915_gem_reset_ring_cleanup(struct drm_i915_private *dev_priv,
>>       }
>>
>>       /* These may not have been flush before the reset, do so now */
>> -     kfree(ring->preallocated_lazy_request);
>> -     ring->preallocated_lazy_request = NULL;
>> -     ring->outstanding_lazy_seqno = 0;
>> +     kfree(ring->outstanding_lazy_request);
>> +     ring->outstanding_lazy_request = NULL;
>
> Somewhat unrelated, but shouldn't we move to refcount even the ring->plr?
> If we allocate it then the ring->plr pointer would hold the ref, then it
> gets transferred to the request list.

Actually this is 100% related to this patch, since it replaces the ol
seqno with the ol request. Would be good to clarify this in the commit
message, since this patch doesn't remove the logic around olr, but
really just does the switch from seqno to request.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 09/21] drm/i915: Make 'i915_gem_check_olr' actually check by request not seqno

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:13PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>

To thin commit message.

Also I wonder whethere we should track the olr state more explicitly in
the request structure instead of jumping through all these hoops. And
explicit olr state for a request might also help to clarify control flow
and checks in a bunch of places.

> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com
> ---
>  drivers/gpu/drm/i915/i915_drv.h      |   17 ++++++++++++++++-
>  drivers/gpu/drm/i915/i915_gem.c      |   25 ++++++++++---------------
>  drivers/gpu/drm/i915/intel_display.c |    2 +-
>  3 files changed, 27 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 1401266..9504206 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -2483,7 +2483,7 @@ bool i915_gem_retire_requests(struct drm_device *dev);
>  void i915_gem_retire_requests_ring(struct intel_engine_cs *ring);
>  int __must_check i915_gem_check_wedge(struct i915_gpu_error *error,
>  				      bool interruptible);
> -int __must_check i915_gem_check_olr(struct intel_engine_cs *ring, u32 seqno);
> +int __must_check i915_gem_check_olr(struct drm_i915_gem_request *req);
>  
>  static inline bool i915_reset_in_progress(struct i915_gpu_error *error)
>  {
> @@ -3020,4 +3020,19 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
>  	}
>  }
>  
> +/************************* Deprecated *************************/

There's a gcc flag for functions if you want to mark this as depracated,
otherwise I'd just go with a "XXX: This temporary function will disappear
at the end of the patch series" somewhere.

> +static inline int __must_check i915_gem_check_ols(struct intel_engine_cs *ring, u32 seqno)
> +{
> +	int ret;
> +
> +	BUG_ON(!mutex_is_locked(&ring->dev->struct_mutex));

WARN_ON instead of BUG_ON for locking checks.

> +
> +	ret = 0;
> +	if (seqno == i915_gem_request_get_seqno(ring->outstanding_lazy_request))
> +		ret = i915_add_request(ring, NULL);
> +
> +	return ret;
> +}
> +/************************* Deprecated *************************/
> +
>  #endif
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 0d0eb26..2c7deca 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -1097,19 +1097,18 @@ i915_gem_check_wedge(struct i915_gpu_error *error,
>  }
>  
>  /*
> - * Compare seqno against outstanding lazy request. Emit a request if they are
> - * equal.
> + * Compare arbitrary request against outstanding lazy request. Emit on match.
>   */
>  int
> -i915_gem_check_olr(struct intel_engine_cs *ring, u32 seqno)
> +i915_gem_check_olr(struct drm_i915_gem_request *req)
>  {
>  	int ret;
>  
> -	BUG_ON(!mutex_is_locked(&ring->dev->struct_mutex));
> +	BUG_ON(!mutex_is_locked(&req->ring->dev->struct_mutex));

Same here. Plus please a stern warning in the commit message and cc: to
whomever who managed to sneak this in (and failed to catch it in review).
>  
>  	ret = 0;
> -	if (seqno == i915_gem_request_get_seqno(ring->outstanding_lazy_request))
> -		ret = i915_add_request(ring, NULL);
> +	if (req == req->ring->outstanding_lazy_request)
> +		ret = i915_add_request(req->ring, NULL);
>  
>  	return ret;
>  }
> @@ -1271,7 +1270,7 @@ i915_wait_seqno(struct intel_engine_cs *ring, uint32_t seqno)
>  	if (ret)
>  		return ret;
>  
> -	ret = i915_gem_check_olr(ring, seqno);
> +	ret = i915_gem_check_ols(ring, seqno);
>  	if (ret)
>  		return ret;
>  
> @@ -1338,7 +1337,6 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  	struct intel_engine_cs *ring = obj->ring;
>  	unsigned reset_counter;
> -	u32 seqno;
>  	int ret;
>  
>  	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
> @@ -1348,21 +1346,18 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
>  	if (!req)
>  		return 0;
>  
> -	seqno = i915_gem_request_get_seqno(req);
> -	BUG_ON(seqno == 0);
> -
>  	ret = i915_gem_check_wedge(&dev_priv->gpu_error, true);
>  	if (ret)
>  		return ret;
>  
> -	ret = i915_gem_check_olr(ring, seqno);
> +	ret = i915_gem_check_olr(req);
>  	if (ret)
>  		return ret;
>  
>  	reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter);
>  	i915_gem_request_reference(req);
>  	mutex_unlock(&dev->struct_mutex);
> -	ret = __wait_seqno(ring, seqno, reset_counter, true, NULL, file_priv);
> +	ret = __wait_seqno(ring, i915_gem_request_get_seqno(req), reset_counter, true, NULL, file_priv);
>  	mutex_lock(&dev->struct_mutex);
>  	i915_gem_request_unreference(req);
>  	if (ret)
> @@ -2786,7 +2781,7 @@ i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
>  	int ret;
>  
>  	if (obj->active) {
> -		ret = i915_gem_check_olr(obj->ring, i915_gem_request_get_seqno(obj->last_read_req));
> +		ret = i915_gem_check_olr(obj->last_read_req);
>  		if (ret)
>  			return ret;
>  
> @@ -2913,7 +2908,7 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
>  	if (seqno <= from->semaphore.sync_seqno[idx]) /* <--- broken?! needs to use i915_seqno_passed()??? */
>  		return 0;
>  
> -	ret = i915_gem_check_olr(obj->ring, seqno);
> +	ret = i915_gem_check_olr(obj->last_read_req);
>  	if (ret)
>  		return ret;
>  
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 6da18c5..2af421e 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -9775,7 +9775,7 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
>  			      i915_gem_request_get_seqno(obj->last_write_req)))
>  		return 0;
>  
> -	ret = i915_gem_check_olr(ring, i915_gem_request_get_seqno(obj->last_write_req));
> +	ret = i915_gem_check_olr(obj->last_write_req);
>  	if (ret)
>  		return ret;
>  
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 10/21] drm/i915: Convert 'last_flip_req' to be a request not a seqno

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:14PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>

I know there's often not a lot to talk about for if you have a refactoring
step that needs to be applied n times. But even then a small commit
message to reiterate what is going on and why and a small note if there's
anything funky goes a long way.

Since in a few months someone will digg out your patch here using git
blame and git lock --pickaxe and will be totally lost without the context
of the entire series. So each patch really needs to be able to be
understood on its own.
-Daniel

> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com
> ---
>  drivers/gpu/drm/i915/intel_overlay.c |   16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
> index dc2f4f2..ccd5732 100644
> --- a/drivers/gpu/drm/i915/intel_overlay.c
> +++ b/drivers/gpu/drm/i915/intel_overlay.c
> @@ -182,7 +182,7 @@ struct intel_overlay {
>  	u32 flip_addr;
>  	struct drm_i915_gem_object *reg_bo;
>  	/* flip handling */
> -	uint32_t last_flip_req;
> +	struct drm_i915_gem_request *last_flip_req;
>  	void (*flip_tail)(struct intel_overlay *);
>  };
>  
> @@ -217,17 +217,17 @@ static int intel_overlay_do_wait_request(struct intel_overlay *overlay,
>  	int ret;
>  
>  	BUG_ON(overlay->last_flip_req);
> -	ret = i915_add_request(ring, &overlay->last_flip_req);
> +	ret = i915_add_request(ring, &overlay->last_flip_req->seqno);
>  	if (ret)
>  		return ret;
>  
>  	overlay->flip_tail = tail;
> -	ret = i915_wait_seqno(ring, overlay->last_flip_req);
> +	ret = i915_wait_seqno(ring, i915_gem_request_get_seqno(overlay->last_flip_req));
>  	if (ret)
>  		return ret;
>  	i915_gem_retire_requests(dev);
>  
> -	overlay->last_flip_req = 0;
> +	overlay->last_flip_req = NULL;
>  	return 0;
>  }
>  
> @@ -286,7 +286,7 @@ static int intel_overlay_continue(struct intel_overlay *overlay,
>  	intel_ring_emit(ring, flip_addr);
>  	intel_ring_advance(ring);
>  
> -	return i915_add_request(ring, &overlay->last_flip_req);
> +	return i915_add_request(ring, &overlay->last_flip_req->seqno);
>  }
>  
>  static void intel_overlay_release_old_vid_tail(struct intel_overlay *overlay)
> @@ -366,10 +366,10 @@ static int intel_overlay_recover_from_interrupt(struct intel_overlay *overlay)
>  	struct intel_engine_cs *ring = &dev_priv->ring[RCS];
>  	int ret;
>  
> -	if (overlay->last_flip_req == 0)
> +	if (overlay->last_flip_req == NULL)
>  		return 0;
>  
> -	ret = i915_wait_seqno(ring, overlay->last_flip_req);
> +	ret = i915_wait_seqno(ring, i915_gem_request_get_seqno(overlay->last_flip_req));
>  	if (ret)
>  		return ret;
>  	i915_gem_retire_requests(dev);
> @@ -377,7 +377,7 @@ static int intel_overlay_recover_from_interrupt(struct intel_overlay *overlay)
>  	if (overlay->flip_tail)
>  		overlay->flip_tail(overlay);
>  
> -	overlay->last_flip_req = 0;
> +	overlay->last_flip_req = NULL;
>  	return 0;
>  }
>  
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 02/21] drm/i915: Remove redundant parameter to i915_gem_object_wait_rendering__tail()

[Daniel Vetter]

On Sun, Oct 19, 2014 at 2:25 PM, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Mon, Oct 06, 2014 at 03:15:06PM +0100, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
>
> Empty commit messages are a bit too thin. E.g. in this case this was an
> oversight from
>
> commit c8725f3dc0911d4354315a65150aecd8b7d0d74a
> Author: Chris Wilson <chris@chris-wilson.co.uk>
> Date:   Mon Mar 17 12:21:55 2014 +0000
>
>     drm/i915: Do not call retire_requests from wait_for_rendering
>
> which means your patch here really should have Cc'ed patch author and
> revierer (i.e. Chris & Brad) of the offending patch, too.

To make things clear: Cc'ing people isn't to assign blame for every
single mistake they do (we're all racking up impressive amounts of
them anyway), but to give them a learning opportunity and the chance
to improve. It is pretty much impossible to follow intel-gfx and read
everything that's on here even for me, so if you don't cc people for
even the most mundane and small things they'll miss the mail.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 08/25] drm/i915: Remove 'outstanding_lazy_seqno'

[Daniel Vetter]

On Fri, Oct 10, 2014 at 12:38:22PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com


This looks like a v2 of the previous patch 08, but the commit message
fails to mention what exactly changed and why.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_gem.c            |   13 +++----
>  drivers/gpu/drm/i915/i915_gem_execbuffer.c |    2 +-
>  drivers/gpu/drm/i915/intel_display.c       |    2 +-
>  drivers/gpu/drm/i915/intel_lrc.c           |   26 +++++---------
>  drivers/gpu/drm/i915/intel_ringbuffer.c    |   52 +++++++++++++++-------------
>  drivers/gpu/drm/i915/intel_ringbuffer.h    |   13 ++-----
>  6 files changed, 46 insertions(+), 62 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 9ce0808..c884188 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -1108,7 +1108,7 @@ i915_gem_check_olr(struct intel_engine_cs *ring, u32 seqno)
>  	BUG_ON(!mutex_is_locked(&ring->dev->struct_mutex));
>  
>  	ret = 0;
> -	if (seqno == ring->outstanding_lazy_seqno)
> +	if (seqno == i915_gem_request_get_seqno(ring->outstanding_lazy_request))
>  		ret = i915_add_request(ring, NULL);
>  
>  	return ret;
> @@ -2344,7 +2344,7 @@ int __i915_add_request(struct intel_engine_cs *ring,
>  	u32 request_ring_position, request_start;
>  	int ret;
>  
> -	request = ring->preallocated_lazy_request;
> +	request = ring->outstanding_lazy_request;
>  	if (WARN_ON(request == NULL))
>  		return -ENOMEM;
>  
> @@ -2391,7 +2391,6 @@ int __i915_add_request(struct intel_engine_cs *ring,
>  
>  	i915_gem_request_reference(request);
>  
> -	request->seqno = intel_ring_get_seqno(ring);
>  	request->ring = ring;
>  	request->head = request_start;
>  	request->tail = request_ring_position;
> @@ -2428,8 +2427,7 @@ int __i915_add_request(struct intel_engine_cs *ring,
>  	}
>  
>  	trace_i915_gem_request_add(ring, request->seqno);
> -	ring->outstanding_lazy_seqno = 0;
> -	ring->preallocated_lazy_request = NULL;
> +	ring->outstanding_lazy_request = NULL;
>  
>  	if (!dev_priv->ums.mm_suspended) {
>  		i915_queue_hangcheck(ring->dev);
> @@ -2605,9 +2603,8 @@ static void i915_gem_reset_ring_cleanup(struct drm_i915_private *dev_priv,
>  	}
>  
>  	/* These may not have been flush before the reset, do so now */
> -	kfree(ring->preallocated_lazy_request);
> -	ring->preallocated_lazy_request = NULL;
> -	ring->outstanding_lazy_seqno = 0;
> +	kfree(ring->outstanding_lazy_request);
> +	ring->outstanding_lazy_request = NULL;
>  }
>  
>  void i915_gem_restore_fences(struct drm_device *dev)
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index 4250211..e0fdfae 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -1170,7 +1170,7 @@ i915_gem_ringbuffer_submission(struct drm_device *dev, struct drm_file *file,
>  			return ret;
>  	}
>  
> -	trace_i915_gem_ring_dispatch(ring, intel_ring_get_seqno(ring), flags);
> +	trace_i915_gem_ring_dispatch(ring, i915_gem_request_get_seqno(intel_ring_get_request(ring)), flags);
>  
>  	i915_gem_execbuffer_move_to_active(vmas, ring);
>  	i915_gem_execbuffer_retire_commands(dev, file, ring, batch_obj);
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 5aae3d1e..6da18c5 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -10053,7 +10053,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  		if (ret)
>  			goto cleanup_unpin;
>  
> -		work->flip_queued_seqno = intel_ring_get_seqno(ring);
> +		work->flip_queued_seqno = i915_gem_request_get_seqno(intel_ring_get_request(ring));
>  		work->flip_queued_ring = ring;
>  	}
>  
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index b5b6430..55c607a 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -793,22 +793,14 @@ void intel_logical_ring_advance_and_submit(struct intel_ringbuffer *ringbuf)
>  	execlists_context_queue(ring, ctx, ringbuf->tail);
>  }
>  
> -static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
> -				    struct intel_context *ctx)
> +static int logical_ring_alloc_request(struct intel_engine_cs *ring,
> +				      struct intel_context *ctx)
>  {
>  	struct drm_i915_gem_request *request;
>  	int ret;
>  
> -	/* The aim is to replace seqno values with request structures. A step
> -	 * along the way is to switch to using the PLR in preference to the
> -	 * OLS. That requires the PLR to only be valid when the OLS is also
> -	 * valid. I.e., the two must be kept in step. */
> -
> -	if (ring->outstanding_lazy_seqno) {
> -		BUG_ON(ring->preallocated_lazy_request == NULL);
> +	if (ring->outstanding_lazy_request)
>  		return 0;
> -	}
> -	BUG_ON(ring->preallocated_lazy_request != NULL);
>  
>  	request = kmalloc(sizeof(*request), GFP_KERNEL);
>  	if (request == NULL)
> @@ -816,7 +808,7 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
>  
>  	kref_init(&request->ref);
>  
> -	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
> +	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
>  	if (ret) {
>  		kfree(request);
>  		return ret;
> @@ -829,7 +821,7 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
>  	request->ctx = ctx;
>  	i915_gem_context_reference(request->ctx);
>  
> -	ring->preallocated_lazy_request = request;
> +	ring->outstanding_lazy_request = request;
>  	return 0;
>  }
>  
> @@ -997,7 +989,7 @@ int intel_logical_ring_begin(struct intel_ringbuffer *ringbuf, int num_dwords)
>  		return ret;
>  
>  	/* Preallocate the olr before touching the ring */
> -	ret = logical_ring_alloc_seqno(ring, ringbuf->FIXME_lrc_ctx);
> +	ret = logical_ring_alloc_request(ring, ringbuf->FIXME_lrc_ctx);
>  	if (ret)
>  		return ret;
>  
> @@ -1212,7 +1204,8 @@ static int gen8_emit_request(struct intel_ringbuffer *ringbuf)
>  				(ring->status_page.gfx_addr +
>  				(I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT)));
>  	intel_logical_ring_emit(ringbuf, 0);
> -	intel_logical_ring_emit(ringbuf, ring->outstanding_lazy_seqno);
> +	intel_logical_ring_emit(ringbuf,
> +		i915_gem_request_get_seqno(ring->outstanding_lazy_request));
>  	intel_logical_ring_emit(ringbuf, MI_USER_INTERRUPT);
>  	intel_logical_ring_emit(ringbuf, MI_NOOP);
>  	intel_logical_ring_advance_and_submit(ringbuf);
> @@ -1235,8 +1228,7 @@ void intel_logical_ring_cleanup(struct intel_engine_cs *ring)
>  
>  	intel_logical_ring_stop(ring);
>  	WARN_ON((I915_READ_MODE(ring) & MODE_IDLE) == 0);
> -	ring->preallocated_lazy_request = NULL;
> -	ring->outstanding_lazy_seqno = 0;
> +	ring->outstanding_lazy_request = NULL;
>  
>  	if (ring->cleanup)
>  		ring->cleanup(ring);
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 7350f78..99544bc 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -895,17 +895,20 @@ static int gen8_rcs_signal(struct intel_engine_cs *signaller,
>  		return ret;
>  
>  	for_each_ring(waiter, dev_priv, i) {
> +		u32 seqno;
>  		u64 gtt_offset = signaller->semaphore.signal_ggtt[i];
>  		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
>  			continue;
>  
> +		seqno = i915_gem_request_get_seqno(
> +					   signaller->outstanding_lazy_request);
>  		intel_ring_emit(signaller, GFX_OP_PIPE_CONTROL(6));
>  		intel_ring_emit(signaller, PIPE_CONTROL_GLOBAL_GTT_IVB |
>  					   PIPE_CONTROL_QW_WRITE |
>  					   PIPE_CONTROL_FLUSH_ENABLE);
>  		intel_ring_emit(signaller, lower_32_bits(gtt_offset));
>  		intel_ring_emit(signaller, upper_32_bits(gtt_offset));
> -		intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
> +		intel_ring_emit(signaller, seqno);
>  		intel_ring_emit(signaller, 0);
>  		intel_ring_emit(signaller, MI_SEMAPHORE_SIGNAL |
>  					   MI_SEMAPHORE_TARGET(waiter->id));
> @@ -933,16 +936,19 @@ static int gen8_xcs_signal(struct intel_engine_cs *signaller,
>  		return ret;
>  
>  	for_each_ring(waiter, dev_priv, i) {
> +		u32 seqno;
>  		u64 gtt_offset = signaller->semaphore.signal_ggtt[i];
>  		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
>  			continue;
>  
> +		seqno = i915_gem_request_get_seqno(
> +					   signaller->outstanding_lazy_request);
>  		intel_ring_emit(signaller, (MI_FLUSH_DW + 1) |
>  					   MI_FLUSH_DW_OP_STOREDW);
>  		intel_ring_emit(signaller, lower_32_bits(gtt_offset) |
>  					   MI_FLUSH_DW_USE_GTT);
>  		intel_ring_emit(signaller, upper_32_bits(gtt_offset));
> -		intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
> +		intel_ring_emit(signaller, seqno);
>  		intel_ring_emit(signaller, MI_SEMAPHORE_SIGNAL |
>  					   MI_SEMAPHORE_TARGET(waiter->id));
>  		intel_ring_emit(signaller, 0);
> @@ -971,9 +977,11 @@ static int gen6_signal(struct intel_engine_cs *signaller,
>  	for_each_ring(useless, dev_priv, i) {
>  		u32 mbox_reg = signaller->semaphore.mbox.signal[i];
>  		if (mbox_reg != GEN6_NOSYNC) {
> +			u32 seqno = i915_gem_request_get_seqno(
> +					   signaller->outstanding_lazy_request);
>  			intel_ring_emit(signaller, MI_LOAD_REGISTER_IMM(1));
>  			intel_ring_emit(signaller, mbox_reg);
> -			intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
> +			intel_ring_emit(signaller, seqno);
>  		}
>  	}
>  
> @@ -1008,7 +1016,8 @@ gen6_add_request(struct intel_engine_cs *ring)
>  
>  	intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
>  	intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
> -	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
> +	intel_ring_emit(ring,
> +		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
>  	intel_ring_emit(ring, MI_USER_INTERRUPT);
>  	__intel_ring_advance(ring);
>  
> @@ -1126,7 +1135,8 @@ pc_render_add_request(struct intel_engine_cs *ring)
>  			PIPE_CONTROL_WRITE_FLUSH |
>  			PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE);
>  	intel_ring_emit(ring, ring->scratch.gtt_offset | PIPE_CONTROL_GLOBAL_GTT);
> -	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
> +	intel_ring_emit(ring,
> +		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
>  	intel_ring_emit(ring, 0);
>  	PIPE_CONTROL_FLUSH(ring, scratch_addr);
>  	scratch_addr += 2 * CACHELINE_BYTES; /* write to separate cachelines */
> @@ -1145,7 +1155,8 @@ pc_render_add_request(struct intel_engine_cs *ring)
>  			PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE |
>  			PIPE_CONTROL_NOTIFY);
>  	intel_ring_emit(ring, ring->scratch.gtt_offset | PIPE_CONTROL_GLOBAL_GTT);
> -	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
> +	intel_ring_emit(ring,
> +		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
>  	intel_ring_emit(ring, 0);
>  	__intel_ring_advance(ring);
>  
> @@ -1385,7 +1396,8 @@ i9xx_add_request(struct intel_engine_cs *ring)
>  
>  	intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
>  	intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
> -	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
> +	intel_ring_emit(ring,
> +		    i915_gem_request_get_seqno(ring->outstanding_lazy_request));
>  	intel_ring_emit(ring, MI_USER_INTERRUPT);
>  	__intel_ring_advance(ring);
>  
> @@ -1839,8 +1851,7 @@ void intel_cleanup_ring_buffer(struct intel_engine_cs *ring)
>  	WARN_ON(!IS_GEN2(ring->dev) && (I915_READ_MODE(ring) & MODE_IDLE) == 0);
>  
>  	intel_destroy_ringbuffer_obj(ringbuf);
> -	ring->preallocated_lazy_request = NULL;
> -	ring->outstanding_lazy_seqno = 0;
> +	ring->outstanding_lazy_request = NULL;
>  
>  	if (ring->cleanup)
>  		ring->cleanup(ring);
> @@ -1980,7 +1991,7 @@ int intel_ring_idle(struct intel_engine_cs *ring)
>  	int ret;
>  
>  	/* We need to add any requests required to flush the objects and ring */
> -	if (ring->outstanding_lazy_seqno) {
> +	if (ring->outstanding_lazy_request) {
>  		ret = i915_add_request(ring, NULL);
>  		if (ret)
>  			return ret;
> @@ -1998,22 +2009,13 @@ int intel_ring_idle(struct intel_engine_cs *ring)
>  }
>  
>  static int
> -intel_ring_alloc_seqno(struct intel_engine_cs *ring)
> +intel_ring_alloc_request(struct intel_engine_cs *ring)
>  {
>  	int ret;
>  	struct drm_i915_gem_request *request;
>  
> -	/* The aim is to replace seqno values with request structures. A step
> -	 * along the way is to switch to using the PLR in preference to the
> -	 * OLS. That requires the PLR to only be valid when the OLS is also
> -	 * valid. I.e., the two must be kept in step. */
> -
> -	if (ring->outstanding_lazy_seqno) {
> -		BUG_ON(ring->preallocated_lazy_request == NULL);
> +	if (ring->outstanding_lazy_request)
>  		return 0;
> -	}
> -
> -	BUG_ON(ring->preallocated_lazy_request != NULL);
>  
>  	request = kmalloc(sizeof(*request), GFP_KERNEL);
>  	if (request == NULL)
> @@ -2021,13 +2023,13 @@ intel_ring_alloc_seqno(struct intel_engine_cs *ring)
>  
>  	kref_init(&request->ref);
>  
> -	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
> +	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
>  	if (ret) {
>  		kfree(request);
>  		return ret;
>  	}
>  
> -	ring->preallocated_lazy_request = request;
> +	ring->outstanding_lazy_request = request;
>  	return 0;
>  }
>  
> @@ -2068,7 +2070,7 @@ int intel_ring_begin(struct intel_engine_cs *ring,
>  		return ret;
>  
>  	/* Preallocate the olr before touching the ring */
> -	ret = intel_ring_alloc_seqno(ring);
> +	ret = intel_ring_alloc_request(ring);
>  	if (ret)
>  		return ret;
>  
> @@ -2103,7 +2105,7 @@ void intel_ring_init_seqno(struct intel_engine_cs *ring, u32 seqno)
>  	struct drm_device *dev = ring->dev;
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  
> -	BUG_ON(ring->outstanding_lazy_seqno);
> +	BUG_ON(ring->outstanding_lazy_request);
>  
>  	if (INTEL_INFO(dev)->gen == 6 || INTEL_INFO(dev)->gen == 7) {
>  		I915_WRITE(RING_SYNC_0(ring->mmio_base), 0);
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
> index d98b964..98b219d 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
> @@ -265,8 +265,7 @@ struct  intel_engine_cs {
>  	/**
>  	 * Do we have some not yet emitted requests outstanding?
>  	 */
> -	struct drm_i915_gem_request *preallocated_lazy_request;
> -	u32 outstanding_lazy_seqno;
> +	struct drm_i915_gem_request *outstanding_lazy_request;
>  	bool gpu_caches_dirty;
>  	bool fbc_dirty;
>  
> @@ -429,17 +428,11 @@ static inline u32 intel_ring_get_tail(struct intel_ringbuffer *ringbuf)
>  	return ringbuf->tail;
>  }
>  
> -static inline u32 intel_ring_get_seqno(struct intel_engine_cs *ring)
> -{
> -	BUG_ON(ring->outstanding_lazy_seqno == 0);
> -	return ring->outstanding_lazy_seqno;
> -}
> -
>  static inline struct drm_i915_gem_request *
>  intel_ring_get_request(struct intel_engine_cs *ring)
>  {
> -	BUG_ON(ring->preallocated_lazy_request == NULL);
> -	return ring->preallocated_lazy_request;
> +	BUG_ON(ring->outstanding_lazy_request == NULL);
> +	return ring->outstanding_lazy_request;
>  }
>  
>  static inline void i915_trace_irq_get(struct intel_engine_cs *ring, u32 seqno)
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 13/21] drm/i915: Convert mmio_flip::seqno to struct request

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:17PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>

Again on the topic of thin commit messages: Beyond the boilerplate blabla
explaining why we do all the s/seqno/request/ stuff for the benefit of the
future reader this definitely needs a mention of the refcounting needed
for the async work.
-Daniel

> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com
> ---
>  drivers/gpu/drm/i915/intel_display.c |   12 +++++++-----
>  drivers/gpu/drm/i915/intel_drv.h     |    2 +-
>  2 files changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 2af421e..f13bc30 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -9799,15 +9799,16 @@ void intel_notify_mmio_flip(struct intel_engine_cs *ring)
>  		struct intel_mmio_flip *mmio_flip;
>  
>  		mmio_flip = &intel_crtc->mmio_flip;
> -		if (mmio_flip->seqno == 0)
> +		if (mmio_flip->req == NULL)
>  			continue;
>  
>  		if (ring->id != mmio_flip->ring_id)
>  			continue;
>  
> -		if (i915_seqno_passed(seqno, mmio_flip->seqno)) {
> +		if (i915_seqno_passed(seqno, i915_gem_request_get_seqno(mmio_flip->req))) {
>  			intel_do_mmio_flip(intel_crtc);
> -			mmio_flip->seqno = 0;
> +			i915_gem_request_unreference(mmio_flip->req);
> +			mmio_flip->req = NULL;
>  			ring->irq_put(ring);
>  		}
>  	}
> @@ -9826,7 +9827,7 @@ static int intel_queue_mmio_flip(struct drm_device *dev,
>  	unsigned long irq_flags;
>  	int ret;
>  
> -	if (WARN_ON(intel_crtc->mmio_flip.seqno))
> +	if (WARN_ON(intel_crtc->mmio_flip.req))
>  		return -EBUSY;
>  
>  	ret = intel_postpone_flip(obj);
> @@ -9838,7 +9839,8 @@ static int intel_queue_mmio_flip(struct drm_device *dev,
>  	}
>  
>  	spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
> -	intel_crtc->mmio_flip.seqno = i915_gem_request_get_seqno(obj->last_write_req);
> +	intel_crtc->mmio_flip.req = obj->last_write_req;
> +	i915_gem_request_reference(intel_crtc->mmio_flip.req);
>  	intel_crtc->mmio_flip.ring_id = obj->ring->id;
>  	spin_unlock_irqrestore(&dev_priv->mmio_flip_lock, irq_flags);
>  
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index dd5e0f1..418ac13 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -395,7 +395,7 @@ struct intel_pipe_wm {
>  };
>  
>  struct intel_mmio_flip {
> -	u32 seqno;
> +	struct drm_i915_gem_request *req;
>  	u32 ring_id;
>  };
>  
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 14/21] drm/i915: Convert 'flip_queued_seqno' into 'flip_queued_request'

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:18PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>

Again on the topic of thin commit message: Some additional words about why
we can noodle around in request structures from hardirq context (those
fields are invariant after add_request) would be good. Since with the
scheduler a lot of that stuff suddenly is a lot less invariant (if we
delay the seqno allocation until we emit requests, which I'm pretty sure
we have to for a bunch of reasons).

> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c  |    4 ++--
>  drivers/gpu/drm/i915/intel_display.c |    9 ++++++---
>  drivers/gpu/drm/i915/intel_drv.h     |    2 +-
>  3 files changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 726a8f0..52ddd19 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -547,11 +547,11 @@ static int i915_gem_pageflip_info(struct seq_file *m, void *data)
>  			if (work->flip_queued_ring) {
>  				seq_printf(m, "Flip queued on %s at seqno %u, next seqno %u [current breadcrumb %u], completed? %d\n",
>  					   work->flip_queued_ring->name,
> -					   work->flip_queued_seqno,
> +					   i915_gem_request_get_seqno(work->flip_queued_req),
>  					   dev_priv->next_seqno,
>  					   work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
>  					   i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
> -							     work->flip_queued_seqno));
> +							     i915_gem_request_get_seqno(work->flip_queued_req)));

Yeah it's no your patch, but this stuff has defintely fallen over the
edge. A prep patch to extract some helper functions to bring sanity to
i915_gem_pageflip_info's indentation levels is needed here imo.
-Daniel

>  			} else
>  				seq_printf(m, "Flip not associated with any ring\n");
>  			seq_printf(m, "Flip queued on frame %d, (was ready on frame %d), now %d\n",
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index f13bc30..26fdd96 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -9879,7 +9879,7 @@ static bool __intel_pageflip_stall_check(struct drm_device *dev,
>  	if (work->flip_ready_vblank == 0) {
>  		if (work->flip_queued_ring &&
>  		    !i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
> -				       work->flip_queued_seqno))
> +				       i915_gem_request_get_seqno(work->flip_queued_req)))
>  			return false;
>  
>  		work->flip_ready_vblank = drm_vblank_count(dev, intel_crtc->pipe);
> @@ -10047,7 +10047,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  		if (ret)
>  			goto cleanup_unpin;
>  
> -		work->flip_queued_seqno = i915_gem_request_get_seqno(obj->last_write_req);
> +		work->flip_queued_req = obj->last_write_req;
>  		work->flip_queued_ring = obj->ring;
>  	} else {
>  		ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, ring,
> @@ -10055,10 +10055,13 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  		if (ret)
>  			goto cleanup_unpin;
>  
> -		work->flip_queued_seqno = i915_gem_request_get_seqno(intel_ring_get_request(ring));
> +		work->flip_queued_req = intel_ring_get_request(ring);
>  		work->flip_queued_ring = ring;
>  	}
>  
> +	if (work->flip_queued_req)
> +		i915_gem_request_reference(work->flip_queued_req);
> +
>  	work->flip_queued_vblank = drm_vblank_count(dev, intel_crtc->pipe);
>  	work->enable_stall_check = true;
>  
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 418ac13..cb5af63 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -687,7 +687,7 @@ struct intel_unpin_work {
>  	u32 flip_count;
>  	u32 gtt_offset;
>  	struct intel_engine_cs *flip_queued_ring;
> -	u32 flip_queued_seqno;
> +	struct drm_i915_gem_request *flip_queued_req;
>  	int flip_queued_vblank;
>  	int flip_ready_vblank;
>  	bool enable_stall_check;
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 16/25] drm/i915: Convert most 'i915_seqno_passed' calls into 'i915_gem_request_completed'

[Daniel Vetter]

On Fri, Oct 10, 2014 at 12:39:49PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c  |    3 +--
>  drivers/gpu/drm/i915/i915_drv.h      |   18 ++++++++++++++++++
>  drivers/gpu/drm/i915/i915_gem.c      |   12 ++++--------
>  drivers/gpu/drm/i915/intel_display.c |   11 +++--------
>  4 files changed, 26 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 52ddd19..e764af9 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -550,8 +550,7 @@ static int i915_gem_pageflip_info(struct seq_file *m, void *data)
>  					   i915_gem_request_get_seqno(work->flip_queued_req),
>  					   dev_priv->next_seqno,
>  					   work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
> -					   i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
> -							     i915_gem_request_get_seqno(work->flip_queued_req)));
> +					   i915_gem_request_completed(work->flip_queued_req, true));
>  			} else
>  				seq_printf(m, "Flip not associated with any ring\n");
>  			seq_printf(m, "Flip queued on frame %d, (was ready on frame %d), now %d\n",
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 6fe3be0..650f712 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1970,6 +1970,12 @@ i915_gem_request_unreference(struct drm_i915_gem_request *req)
>  	kref_put(&req->ref, i915_gem_request_free);
>  }
>  
> +/*
> + * NB: i915_gem_request_completed should be here but currently needs the
> + * definition of i915_seqno_passed() which is below. It will be moved in
> + * a later patch when the call to i915_seqno_passed() is obsoleted...
> + */
> +
>  struct drm_i915_file_private {
>  	struct drm_i915_private *dev_priv;
>  	struct drm_file *file;
> @@ -3019,4 +3025,16 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
>  	}
>  }
>  
> +static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
> +					      bool lazy_coherency)
> +{
> +	u32 seqno;
> +
> +	BUG_ON(req == NULL);
> +
> +	seqno = req->ring->get_seqno(req->ring, lazy_coherency);
> +
> +	return i915_seqno_passed(seqno, req->seqno);
> +}

Tbh this thing looks a bit big for a static inline. Have you
double-checked that inlining this doesn't increase binary size? If it
does then we need performance data justifying the cost. Same probably
applies to some of the other static inline functions you've added.
-Daniel

> +
>  #endif
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index e1a58f1..b602e8c 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2253,8 +2253,7 @@ i915_gem_object_retire(struct drm_i915_gem_object *obj)
>  	if (ring == NULL)
>  		return;
>  
> -	if (i915_seqno_passed(ring->get_seqno(ring, true),
> -			      i915_gem_request_get_seqno(obj->last_read_req)))
> +	if (i915_gem_request_completed(obj->last_read_req, true))
>  		i915_gem_object_move_to_inactive(obj);
>  }
>  
> @@ -2521,12 +2520,9 @@ struct drm_i915_gem_request *
>  i915_gem_find_active_request(struct intel_engine_cs *ring)
>  {
>  	struct drm_i915_gem_request *request;
> -	u32 completed_seqno;
> -
> -	completed_seqno = ring->get_seqno(ring, false);
>  
>  	list_for_each_entry(request, &ring->request_list, list) {
> -		if (i915_seqno_passed(completed_seqno, request->seqno))
> +		if (i915_gem_request_completed(request, false))
>  			continue;
>  
>  		return request;
> @@ -2670,7 +2666,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
>  				      struct drm_i915_gem_object,
>  				      ring_list);
>  
> -		if (!i915_seqno_passed(seqno, i915_gem_request_get_seqno(obj->last_read_req)))
> +		if (!i915_gem_request_completed(obj->last_read_req, true))
>  			break;
>  
>  		i915_gem_object_move_to_inactive(obj);
> @@ -2685,7 +2681,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
>  					   struct drm_i915_gem_request,
>  					   list);
>  
> -		if (!i915_seqno_passed(seqno, request->seqno))
> +		if (!i915_gem_request_completed(request, true))
>  			break;
>  
>  		trace_i915_gem_request_retire(ring, request->seqno);
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 26fdd96..9ca8f94 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -9771,8 +9771,7 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
>  
>  	ring = obj->ring;
>  
> -	if (i915_seqno_passed(ring->get_seqno(ring, true),
> -			      i915_gem_request_get_seqno(obj->last_write_req)))
> +	if (i915_gem_request_completed(obj->last_write_req, true))
>  		return 0;
>  
>  	ret = i915_gem_check_olr(obj->last_write_req);
> @@ -9790,9 +9789,6 @@ void intel_notify_mmio_flip(struct intel_engine_cs *ring)
>  	struct drm_i915_private *dev_priv = to_i915(ring->dev);
>  	struct intel_crtc *intel_crtc;
>  	unsigned long irq_flags;
> -	u32 seqno;
> -
> -	seqno = ring->get_seqno(ring, false);
>  
>  	spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
>  	for_each_intel_crtc(ring->dev, intel_crtc) {
> @@ -9805,7 +9801,7 @@ void intel_notify_mmio_flip(struct intel_engine_cs *ring)
>  		if (ring->id != mmio_flip->ring_id)
>  			continue;
>  
> -		if (i915_seqno_passed(seqno, i915_gem_request_get_seqno(mmio_flip->req))) {
> +		if (i915_gem_request_completed(mmio_flip->req, false)) {
>  			intel_do_mmio_flip(intel_crtc);
>  			i915_gem_request_unreference(mmio_flip->req);
>  			mmio_flip->req = NULL;
> @@ -9878,8 +9874,7 @@ static bool __intel_pageflip_stall_check(struct drm_device *dev,
>  
>  	if (work->flip_ready_vblank == 0) {
>  		if (work->flip_queued_ring &&
> -		    !i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
> -				       i915_gem_request_get_seqno(work->flip_queued_req)))
> +		    !i915_gem_request_completed(work->flip_queued_req, true))
>  			return false;
>  
>  		work->flip_ready_vblank = drm_vblank_count(dev, intel_crtc->pipe);
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 19/21] drm/i915: Convert semaphores to handle requests not seqnos

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:23PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com

This smells funky on a quick look. I'd expect some reference counting in
here, or at least an explanatation for why it's not needed.

But even without that I'm not sure we want to track requests at the
semaphore level. After all hw semaphores work with seqno numbers and not
requests, and depending upon how the scheduler materializes seqnos
shoveling requests through these functions makes no sense at all.

I'm maybe missing something big here, but with the thin commit message I
can't tell. So I vote to just drop this one for now.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_debugfs.c     |    3 ++-
>  drivers/gpu/drm/i915/i915_gem.c         |   14 ++++++--------
>  drivers/gpu/drm/i915/i915_gpu_error.c   |   12 ++++++++----
>  drivers/gpu/drm/i915/intel_ringbuffer.c |   10 ++++++----
>  drivers/gpu/drm/i915/intel_ringbuffer.h |    4 ++--
>  5 files changed, 24 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index e764af9..df53515 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2604,7 +2604,8 @@ static int i915_semaphore_status(struct seq_file *m, void *unused)
>  	seq_puts(m, "\nSync seqno:\n");
>  	for_each_ring(ring, dev_priv, i) {
>  		for (j = 0; j < num_rings; j++) {
> -			seq_printf(m, "  0x%08x ", ring->semaphore.sync_seqno[j]);
> +			seq_printf(m, "  0x%08x ",
> +				   i915_gem_request_get_seqno(ring->semaphore.sync_req[j]));
>  		}
>  		seq_putc(m, '\n');
>  	}
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 2e1ebad..d40dad7 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2275,8 +2275,8 @@ i915_gem_init_seqno(struct drm_device *dev, u32 seqno)
>  	for_each_ring(ring, dev_priv, i) {
>  		intel_ring_init_seqno(ring, seqno);
>  
> -		for (j = 0; j < ARRAY_SIZE(ring->semaphore.sync_seqno); j++)
> -			ring->semaphore.sync_seqno[j] = 0;
> +		for (j = 0; j < ARRAY_SIZE(ring->semaphore.sync_req); j++)
> +			ring->semaphore.sync_req[j] = NULL;
>  	}
>  
>  	return 0;
> @@ -2877,7 +2877,6 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
>  		     struct intel_engine_cs *to)
>  {
>  	struct intel_engine_cs *from = obj->ring;
> -	u32 seqno;
>  	int ret, idx;
>  
>  	if (from == NULL || to == from)
> @@ -2888,10 +2887,10 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
>  
>  	idx = intel_ring_sync_index(from, to);
>  
> -	seqno = i915_gem_request_get_seqno(obj->last_read_req);
>  	/* Optimization: Avoid semaphore sync when we are sure we already
>  	 * waited for an object with higher seqno */
> -	if (seqno <= from->semaphore.sync_seqno[idx]) /* <--- broken?! needs to use i915_seqno_passed()??? */
> +	if (i915_gem_request_get_seqno(obj->last_read_req) <=
> +		i915_gem_request_get_seqno(from->semaphore.sync_req[idx])) /* <--- broken?! needs to use i915_seqno_passed()??? */
>  		return 0;
>  
>  	ret = i915_gem_check_olr(obj->last_read_req);
> @@ -2899,14 +2898,13 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
>  		return ret;
>  
>  	trace_i915_gem_ring_sync_to(from, to, obj->last_read_req);
> -	ret = to->semaphore.sync_to(to, from, seqno);
> +	ret = to->semaphore.sync_to(to, from, obj->last_read_req);
>  	if (!ret)
>  		/* We use last_read_req because sync_to()
>  		 * might have just caused seqno wrap under
>  		 * the radar.
>  		 */
> -		from->semaphore.sync_seqno[idx] =
> -				i915_gem_request_get_seqno(obj->last_read_req);
> +		from->semaphore.sync_req[idx] = obj->last_read_req;
>  
>  	return ret;
>  }
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index 1b58390..9545d96 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -822,7 +822,8 @@ static void gen8_record_semaphore_state(struct drm_i915_private *dev_priv,
>  		idx = intel_ring_sync_index(ring, to);
>  
>  		ering->semaphore_mboxes[idx] = tmp[signal_offset];
> -		ering->semaphore_seqno[idx] = ring->semaphore.sync_seqno[idx];
> +		ering->semaphore_seqno[idx] =
> +		      i915_gem_request_get_seqno(ring->semaphore.sync_req[idx]);
>  	}
>  }
>  
> @@ -832,13 +833,16 @@ static void gen6_record_semaphore_state(struct drm_i915_private *dev_priv,
>  {
>  	ering->semaphore_mboxes[0] = I915_READ(RING_SYNC_0(ring->mmio_base));
>  	ering->semaphore_mboxes[1] = I915_READ(RING_SYNC_1(ring->mmio_base));
> -	ering->semaphore_seqno[0] = ring->semaphore.sync_seqno[0];
> -	ering->semaphore_seqno[1] = ring->semaphore.sync_seqno[1];
> +	ering->semaphore_seqno[0] =
> +			i915_gem_request_get_seqno(ring->semaphore.sync_req[0]);
> +	ering->semaphore_seqno[1] =
> +			i915_gem_request_get_seqno(ring->semaphore.sync_req[1]);
>  
>  	if (HAS_VEBOX(dev_priv->dev)) {
>  		ering->semaphore_mboxes[2] =
>  			I915_READ(RING_SYNC_2(ring->mmio_base));
> -		ering->semaphore_seqno[2] = ring->semaphore.sync_seqno[2];
> +		ering->semaphore_seqno[2] =
> +			i915_gem_request_get_seqno(ring->semaphore.sync_req[2]);
>  	}
>  }
>  
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index c8ec78c..0a3c24a 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -1042,7 +1042,7 @@ static inline bool i915_gem_has_seqno_wrapped(struct drm_device *dev,
>  static int
>  gen8_ring_sync(struct intel_engine_cs *waiter,
>  	       struct intel_engine_cs *signaller,
> -	       u32 seqno)
> +	       struct drm_i915_gem_request *req)
>  {
>  	struct drm_i915_private *dev_priv = waiter->dev->dev_private;
>  	int ret;
> @@ -1055,7 +1055,7 @@ gen8_ring_sync(struct intel_engine_cs *waiter,
>  				MI_SEMAPHORE_GLOBAL_GTT |
>  				MI_SEMAPHORE_POLL |
>  				MI_SEMAPHORE_SAD_GTE_SDD);
> -	intel_ring_emit(waiter, seqno);
> +	intel_ring_emit(waiter, i915_gem_request_get_seqno(req));
>  	intel_ring_emit(waiter,
>  			lower_32_bits(GEN8_WAIT_OFFSET(waiter, signaller->id)));
>  	intel_ring_emit(waiter,
> @@ -1067,18 +1067,20 @@ gen8_ring_sync(struct intel_engine_cs *waiter,
>  static int
>  gen6_ring_sync(struct intel_engine_cs *waiter,
>  	       struct intel_engine_cs *signaller,
> -	       u32 seqno)
> +	       struct drm_i915_gem_request *req)
>  {
>  	u32 dw1 = MI_SEMAPHORE_MBOX |
>  		  MI_SEMAPHORE_COMPARE |
>  		  MI_SEMAPHORE_REGISTER;
>  	u32 wait_mbox = signaller->semaphore.mbox.wait[waiter->id];
>  	int ret;
> +	u32 seqno;
>  
>  	/* Throughout all of the GEM code, seqno passed implies our current
>  	 * seqno is >= the last seqno executed. However for hardware the
>  	 * comparison is strictly greater than.
>  	 */
> +	seqno = i915_gem_request_get_seqno(req);
>  	seqno -= 1;
>  
>  	WARN_ON(wait_mbox == MI_SEMAPHORE_SYNC_INVALID);
> @@ -1794,7 +1796,7 @@ static int intel_init_ring_buffer(struct drm_device *dev,
>  	INIT_LIST_HEAD(&ring->execlist_queue);
>  	ringbuf->size = 32 * PAGE_SIZE;
>  	ringbuf->ring = ring;
> -	memset(ring->semaphore.sync_seqno, 0, sizeof(ring->semaphore.sync_seqno));
> +	memset(ring->semaphore.sync_req, 0, sizeof(ring->semaphore.sync_req));
>  
>  	init_waitqueue_head(&ring->irq_queue);
>  
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
> index 5475046..64a4346 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
> @@ -211,7 +211,7 @@ struct  intel_engine_cs {
>  	 *  ie. transpose of f(x, y)
>  	 */
>  	struct {
> -		u32	sync_seqno[I915_NUM_RINGS-1];
> +		struct drm_i915_gem_request *sync_req[I915_NUM_RINGS-1];
>  
>  		union {
>  			struct {
> @@ -226,7 +226,7 @@ struct  intel_engine_cs {
>  		/* AKA wait() */
>  		int	(*sync_to)(struct intel_engine_cs *ring,
>  				   struct intel_engine_cs *to,
> -				   u32 seqno);
> +				   struct drm_i915_gem_request *req);
>  		int	(*signal)(struct intel_engine_cs *signaller,
>  				  /* num_dwords needed by caller */
>  				  unsigned int num_dwords);
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 20/21] drm/i915: Convert 'ring_idle()' to use requests not seqnos

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:24PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com

We have places that shovel stuff onto the ring without an explicit
add_request. Or at least we've had, so this needs a full audit, and that
audit needs to be in the commit message.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_irq.c |   12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 4847ed5..c2a7127 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -3030,18 +3030,18 @@ static void gen8_disable_vblank(struct drm_device *dev, int pipe)
>  	spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
>  }
>  
> -static u32
> -ring_last_seqno(struct intel_engine_cs *ring)
> +static struct drm_i915_gem_request *
> +ring_last_request(struct intel_engine_cs *ring)
>  {
>  	return list_entry(ring->request_list.prev,
> -			  struct drm_i915_gem_request, list)->seqno;
> +			  struct drm_i915_gem_request, list);
>  }
>  
>  static bool
> -ring_idle(struct intel_engine_cs *ring, u32 seqno)
> +ring_idle(struct intel_engine_cs *ring)
>  {
>  	return (list_empty(&ring->request_list) ||
> -		i915_seqno_passed(seqno, ring_last_seqno(ring)));
> +		i915_gem_request_completed(ring_last_request(ring), false));
>  }
>  
>  static bool
> @@ -3261,7 +3261,7 @@ static void i915_hangcheck_elapsed(unsigned long data)
>  		acthd = intel_ring_get_active_head(ring);
>  
>  		if (ring->hangcheck.seqno == seqno) {
> -			if (ring_idle(ring, seqno)) {
> +			if (ring_idle(ring)) {
>  				ring->hangcheck.action = HANGCHECK_IDLE;
>  
>  				if (waitqueue_active(&ring->irq_queue)) {
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 21/21] drm/i915: Remove 'obj->ring'

[Daniel Vetter]

On Mon, Oct 06, 2014 at 03:15:25PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com

I think this should be split up into the different parts:

- s/obj->ring/obj->last_read_req->ring/ for all the cases that just want
  the current ring.
- s/obj->ring/obj->last_read_req/ I think in a bunch of places the code
  would actually be more readable if we'd check for obj->active instead.
- All the oddball special cases probably deserve their own commit + nice
  explanation in the commit message about why the change is correct.

Cheers, Daniel
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c     |    9 +++++----
>  drivers/gpu/drm/i915/i915_drv.h         |    2 --
>  drivers/gpu/drm/i915/i915_gem.c         |   32 +++++++++++++++++++------------
>  drivers/gpu/drm/i915/i915_gem_context.c |   12 +++++++++++-
>  drivers/gpu/drm/i915/i915_gpu_error.c   |    3 ++-
>  drivers/gpu/drm/i915/intel_display.c    |   15 ++++++++-------
>  6 files changed, 46 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index df53515..b1d989f 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -168,8 +168,9 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj)
>  		*t = '\0';
>  		seq_printf(m, " (%s mappable)", s);
>  	}
> -	if (obj->ring != NULL)
> -		seq_printf(m, " (%s)", obj->ring->name);
> +	if (obj->last_read_req != NULL)
> +		seq_printf(m, " (%s)",
> +			   i915_gem_request_get_ring(obj->last_read_req)->name);
>  	if (obj->frontbuffer_bits)
>  		seq_printf(m, " (frontbuffer: 0x%03x)", obj->frontbuffer_bits);
>  }
> @@ -336,7 +337,7 @@ static int per_file_stats(int id, void *ptr, void *data)
>  			if (ppgtt->file_priv != stats->file_priv)
>  				continue;
>  
> -			if (obj->ring) /* XXX per-vma statistic */
> +			if (obj->last_read_req) /* XXX per-vma statistic */
>  				stats->active += obj->base.size;
>  			else
>  				stats->inactive += obj->base.size;
> @@ -346,7 +347,7 @@ static int per_file_stats(int id, void *ptr, void *data)
>  	} else {
>  		if (i915_gem_obj_ggtt_bound(obj)) {
>  			stats->global += obj->base.size;
> -			if (obj->ring)
> +			if (obj->last_read_req)
>  				stats->active += obj->base.size;
>  			else
>  				stats->inactive += obj->base.size;
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 0790593..cdbbdeb 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1859,8 +1859,6 @@ struct drm_i915_gem_object {
>  	void *dma_buf_vmapping;
>  	int vmapping_count;
>  
> -	struct intel_engine_cs *ring;
> -
>  	/** Breadcrumb of last rendering to the buffer. */
>  	struct drm_i915_gem_request *last_read_req;
>  	struct drm_i915_gem_request *last_write_req;
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index d40dad7..561fb81 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2184,14 +2184,18 @@ static void
>  i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
>  			       struct intel_engine_cs *ring)
>  {
> -	struct drm_i915_gem_request *req = intel_ring_get_request(ring);
> +	struct drm_i915_gem_request *req;
> +	struct intel_engine_cs *old_ring;
>  
>  	BUG_ON(ring == NULL);
> -	if (obj->ring != ring && obj->last_write_req) {
> +
> +	req = intel_ring_get_request(ring);
> +	old_ring = i915_gem_request_get_ring(obj->last_read_req);
> +
> +	if (old_ring != ring && obj->last_write_req) {
>  		/* Keep the request relative to the current ring */
>  		obj->last_write_req = req;
>  	}
> -	obj->ring = ring;
>  
>  	/* Add a reference if we're newly entering the active list. */
>  	if (!obj->active) {
> @@ -2230,7 +2234,6 @@ i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
>  	intel_fb_obj_flush(obj, true);
>  
>  	list_del_init(&obj->ring_list);
> -	obj->ring = NULL;
>  
>  	obj->last_read_req = NULL;
>  	obj->last_write_req = NULL;
> @@ -2247,9 +2250,7 @@ i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
>  static void
>  i915_gem_object_retire(struct drm_i915_gem_object *obj)
>  {
> -	struct intel_engine_cs *ring = obj->ring;
> -
> -	if (ring == NULL)
> +	if (obj->last_read_req == NULL)
>  		return;
>  
>  	if (i915_gem_request_completed(obj->last_read_req, true))
> @@ -2769,14 +2770,17 @@ i915_gem_idle_work_handler(struct work_struct *work)
>  static int
>  i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
>  {
> +	struct intel_engine_cs *ring;
>  	int ret;
>  
>  	if (obj->active) {
> +		ring = i915_gem_request_get_ring(obj->last_read_req);
> +
>  		ret = i915_gem_check_olr(obj->last_read_req);
>  		if (ret)
>  			return ret;
>  
> -		i915_gem_retire_requests_ring(obj->ring);
> +		i915_gem_retire_requests_ring(ring);
>  	}
>  
>  	return 0;
> @@ -2876,9 +2880,11 @@ int
>  i915_gem_object_sync(struct drm_i915_gem_object *obj,
>  		     struct intel_engine_cs *to)
>  {
> -	struct intel_engine_cs *from = obj->ring;
> +	struct intel_engine_cs *from;
>  	int ret, idx;
>  
> +	from = i915_gem_request_get_ring(obj->last_read_req);
> +
>  	if (from == NULL || to == from)
>  		return 0;
>  
> @@ -3889,7 +3895,7 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
>  	bool was_pin_display;
>  	int ret;
>  
> -	if (pipelined != obj->ring) {
> +	if (pipelined != i915_gem_request_get_ring(obj->last_read_req)) {
>  		ret = i915_gem_object_sync(obj, pipelined);
>  		if (ret)
>  			return ret;
> @@ -4303,9 +4309,11 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
>  	ret = i915_gem_object_flush_active(obj);
>  
>  	args->busy = obj->active;
> -	if (obj->ring) {
> +	if (obj->last_read_req) {
> +		struct intel_engine_cs *ring;
>  		BUILD_BUG_ON(I915_NUM_RINGS > 16);
> -		args->busy |= intel_ring_flag(obj->ring) << 16;
> +		ring = i915_gem_request_get_ring(obj->last_read_req);
> +		args->busy |= intel_ring_flag(ring) << 16;
>  	}
>  
>  	drm_gem_object_unreference(&obj->base);
> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
> index a5221d8..8f24831 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
> @@ -613,7 +613,17 @@ static int do_switch(struct intel_engine_cs *ring,
>  		 * swapped, but there is no way to do that yet.
>  		 */
>  		from->legacy_hw_ctx.rcs_state->dirty = 1;
> -		BUG_ON(from->legacy_hw_ctx.rcs_state->ring != ring);
> +
> +		/* BUG_ON(i915_gem_request_get_ring(
> +			from->legacy_hw_ctx.rcs_state->last_read_req) != ring); */
> +		/* NB: last_read_req has already been updated to the current
> +		 * request however, that request has not yet been submitted.
> +		 * Thus last_read_req->ring is guaranteed to be null!
> +		 * NB2: Doing the check before the update of last_read_req
> +		 * (which happens in i915_vma_move_to_active() just above),
> +		 * also fails because last_read_req is almost always null on
> +		 * entry!
> +		 */
>  
>  		/* obj is kept alive until the next request by its active ref */
>  		i915_gem_object_ggtt_unpin(from->legacy_hw_ctx.rcs_state);
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index 9545d96..b9ecbd9 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -681,7 +681,8 @@ static void capture_bo(struct drm_i915_error_buffer *err,
>  	err->dirty = obj->dirty;
>  	err->purgeable = obj->madv != I915_MADV_WILLNEED;
>  	err->userptr = obj->userptr.mm != NULL;
> -	err->ring = obj->ring ? obj->ring->id : -1;
> +	err->ring = obj->last_read_req ?
> +			i915_gem_request_get_ring(obj->last_read_req)->id : -1;
>  	err->cache_level = obj->cache_level;
>  }
>  
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 9ca8f94..8238aac 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -9728,7 +9728,7 @@ static bool use_mmio_flip(struct intel_engine_cs *ring,
>  	else if (i915.enable_execlists)
>  		return true;
>  	else
> -		return ring != obj->ring;
> +		return ring != i915_gem_request_get_ring(obj->last_read_req);
>  }
>  
>  static void intel_do_mmio_flip(struct intel_crtc *intel_crtc)
> @@ -9769,8 +9769,6 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
>  	if (!obj->last_write_req)
>  		return 0;
>  
> -	ring = obj->ring;
> -
>  	if (i915_gem_request_completed(obj->last_write_req, true))
>  		return 0;
>  
> @@ -9778,6 +9776,7 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
>  	if (ret)
>  		return ret;
>  
> +	ring = i915_gem_request_get_ring(obj->last_write_req);
>  	if (WARN_ON(!ring->irq_get(ring)))
>  		return 0;
>  
> @@ -9837,14 +9836,15 @@ static int intel_queue_mmio_flip(struct drm_device *dev,
>  	spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
>  	intel_crtc->mmio_flip.req = obj->last_write_req;
>  	i915_gem_request_reference(intel_crtc->mmio_flip.req);
> -	intel_crtc->mmio_flip.ring_id = obj->ring->id;
> +	BUG_ON(ring != i915_gem_request_get_ring(intel_crtc->mmio_flip.req));
> +	intel_crtc->mmio_flip.ring_id = ring->id;
>  	spin_unlock_irqrestore(&dev_priv->mmio_flip_lock, irq_flags);
>  
>  	/*
>  	 * Double check to catch cases where irq fired before
>  	 * mmio flip data was ready
>  	 */
> -	intel_notify_mmio_flip(obj->ring);
> +	intel_notify_mmio_flip(ring);
>  	return 0;
>  }
>  
> @@ -10022,7 +10022,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  	} else if (IS_IVYBRIDGE(dev)) {
>  		ring = &dev_priv->ring[BCS];
>  	} else if (INTEL_INFO(dev)->gen >= 7) {
> -		ring = obj->ring;
> +		ring = i915_gem_request_get_ring(obj->last_read_req);
>  		if (ring == NULL || ring->id != RCS)
>  			ring = &dev_priv->ring[BCS];
>  	} else {
> @@ -10043,7 +10043,8 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  			goto cleanup_unpin;
>  
>  		work->flip_queued_req = obj->last_write_req;
> -		work->flip_queued_ring = obj->ring;
> +		work->flip_queued_ring =
> +				i915_gem_request_get_ring(obj->last_write_req);
>  	} else {
>  		ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, ring,
>  						   page_flip_flags);
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 22/21] drm/i915: Cache request completion status

[Daniel Vetter]

On Tue, Oct 07, 2014 at 05:47:29PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com

Why? If it's just for performance I think we should do this as part of the
switch to struct fence, which already has this.
> ---
>  drivers/gpu/drm/i915/i915_drv.h         |   34 ++++++++++++++++---------------
>  drivers/gpu/drm/i915/i915_gem.c         |   21 +++++++++++++++++++
>  drivers/gpu/drm/i915/intel_lrc.c        |    1 +
>  drivers/gpu/drm/i915/intel_ringbuffer.c |    2 ++
>  drivers/gpu/drm/i915/intel_ringbuffer.h |    3 +++
>  5 files changed, 45 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index cdbbdeb..4ab3b23 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1913,6 +1913,9 @@ void i915_gem_track_fb(struct drm_i915_gem_object *old,
>  struct drm_i915_gem_request {
>  	struct kref ref;
>  
> +	/** Is this request known to be complete? */
> +	bool complete;
> +
>  	/** On Which ring this request was generated */
>  	struct intel_engine_cs *ring;
>  
> @@ -1943,6 +1946,8 @@ struct drm_i915_gem_request {
>  };
>  
>  void i915_gem_request_free(struct kref *req_ref);
> +void i915_gem_complete_requests_ring(struct intel_engine_cs *ring,
> +				     bool lazy_coherency);
>  
>  static inline uint32_t
>  i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
> @@ -1968,7 +1973,19 @@ i915_gem_request_unreference(struct drm_i915_gem_request *req)
>  	kref_put(&req->ref, i915_gem_request_free);
>  }
>  
> -/* ??? i915_gem_request_completed should be here ??? */
> +static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
> +					      bool lazy_coherency)
> +{
> +	if (req->complete)
> +		return true;
> +
> +	if (req->ring == NULL)
> +		return false;
> +
> +	i915_gem_complete_requests_ring(req->ring, lazy_coherency);
> +
> +	return req->complete;
> +}

Also, this is looking way too big now I think ;-) If you have a full
non-inline function call in your inline it's always a net loss.
-Daniel

>  
>  struct drm_i915_file_private {
>  	struct drm_i915_private *dev_priv;
> @@ -3019,19 +3036,4 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
>  	}
>  }
>  
> -static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
> -					      bool lazy_coherency)
> -{
> -	u32 seqno;
> -
> -	BUG_ON(req == NULL);
> -
> -	if (req->ring == NULL)
> -		return false;
> -
> -	seqno = req->ring->get_seqno(req->ring, lazy_coherency);
> -
> -	return i915_seqno_passed(seqno, req->seqno);
> -}
> -
>  #endif
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 0f14333..0a9b29e 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2641,6 +2641,27 @@ void i915_gem_reset(struct drm_device *dev)
>  	i915_gem_restore_fences(dev);
>  }
>  
> +void i915_gem_complete_requests_ring(struct intel_engine_cs *ring,
> +				     bool lazy_coherency)
> +{
> +	struct drm_i915_gem_request *req;
> +	u32 seqno;
> +
> +	seqno = ring->get_seqno(ring, lazy_coherency);
> +	if (seqno == ring->last_read_seqno)
> +		return;
> +
> +	list_for_each_entry(req, &ring->request_list, list) {
> +		if (req->complete)
> +			continue;
> +
> +		if (i915_seqno_passed(seqno, req->seqno))
> +			req->complete = true;
> +	}
> +
> +	ring->last_read_seqno = seqno;
> +}
> +
>  /**
>   * This function clears the request list as sequence numbers are passed.
>   */
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index 744684a..57acd2a 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -808,6 +808,7 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
>  
>  	kref_init(&request->ref);
>  	request->ring = NULL;
> +	request->complete = false;
>  
>  	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
>  	if (ret) {
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 0a3c24a..392dc25 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -2023,6 +2023,7 @@ intel_ring_alloc_seqno(struct intel_engine_cs *ring)
>  
>  	kref_init(&request->ref);
>  	request->ring = NULL;
> +	request->complete = false;
>  
>  	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
>  	if (ret) {
> @@ -2115,6 +2116,7 @@ void intel_ring_init_seqno(struct intel_engine_cs *ring, u32 seqno)
>  			I915_WRITE(RING_SYNC_2(ring->mmio_base), 0);
>  	}
>  
> +	ring->last_read_seqno = 0;
>  	ring->set_seqno(ring, seqno);
>  	ring->hangcheck.seqno = seqno;
>  }
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
> index 64a4346..40394d3 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
> @@ -269,6 +269,9 @@ struct  intel_engine_cs {
>  	bool gpu_caches_dirty;
>  	bool fbc_dirty;
>  
> +	/* For optimising request completion events */
> +	u32 last_read_seqno;
> +
>  	wait_queue_head_t irq_queue;
>  
>  	struct intel_context *default_context;
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 24/25] drm/i915: Zero fill the request structure

[Daniel Vetter]

On Fri, Oct 10, 2014 at 12:41:12PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com

I think this should be squashed (well, split first) into the relevant
earlier patches. Generally I much prefer kzalloc, and we use that almost
everywhere.

Or does this silently fix some issue and doesn't tell?
-Daniel

> ---
>  drivers/gpu/drm/i915/intel_lrc.c        |    3 +--
>  drivers/gpu/drm/i915/intel_ringbuffer.c |    3 +--
>  2 files changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index 97e6b92..5a75eb5 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -802,13 +802,12 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring,
>  	if (ring->outstanding_lazy_request)
>  		return 0;
>  
> -	request = kmalloc(sizeof(*request), GFP_KERNEL);
> +	request = kzalloc(sizeof(*request), GFP_KERNEL);
>  	if (request == NULL)
>  		return -ENOMEM;
>  
>  	kref_init(&request->ref);
>  	request->ring = ring;
> -	request->complete = false;
>  
>  	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
>  	if (ret) {
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index df9c7e3..0f2719d 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -2017,13 +2017,12 @@ intel_ring_alloc_request(struct intel_engine_cs *ring)
>  	if (ring->outstanding_lazy_request)
>  		return 0;
>  
> -	request = kmalloc(sizeof(*request), GFP_KERNEL);
> +	request = kzalloc(sizeof(*request), GFP_KERNEL);
>  	if (request == NULL)
>  		return -ENOMEM;
>  
>  	kref_init(&request->ref);
>  	request->ring = ring;
> -	request->complete = false;
>  
>  	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
>  	if (ret) {
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 25/25] drm/i915: Defer seqno allocation until actual hardware submission time

[Daniel Vetter]

On Fri, Oct 10, 2014 at 12:41:33PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com

Now I'm confused ... patch 3 made it sound like having the request and the
seqno allocated at different points is a really fragile idea? Or is this
now all save with everyone using struct request? Please elaborate.

I think the idea is solid, since with the scheduler we'll probably want to
allocate the seqno even later (to avoid having to deal with out-of-order
seqnos).
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_drv.h         |    5 ++++-
>  drivers/gpu/drm/i915/i915_gem.c         |   28 +++++++++++++++++++++++++++-
>  drivers/gpu/drm/i915/intel_lrc.c        |   10 ++++------
>  drivers/gpu/drm/i915/intel_ringbuffer.c |   10 ++++------
>  4 files changed, 39 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index e46c78c..d797975 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1979,6 +1979,9 @@ static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
>  	if (req->complete)
>  		return true;
>  
> +	if (req->seqno == 0)
> +		return false;
> +
>  	i915_gem_complete_requests_ring(req->ring, lazy_coherency);
>  
>  	return req->complete;
> @@ -2482,7 +2485,7 @@ i915_seqno_passed(uint32_t seq1, uint32_t seq2)
>  	return (int32_t)(seq1 - seq2) >= 0;
>  }
>  
> -int __must_check i915_gem_get_seqno(struct drm_device *dev, u32 *seqno);
> +int __must_check i915_gem_prepare_next_seqno(struct drm_device *dev);
>  int __must_check i915_gem_set_seqno(struct drm_device *dev, u32 seqno);
>  int __must_check i915_gem_object_get_fence(struct drm_i915_gem_object *obj);
>  int __must_check i915_gem_object_put_fence(struct drm_i915_gem_object *obj);
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 260ef47..7db84b2 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2310,12 +2310,15 @@ int i915_gem_set_seqno(struct drm_device *dev, u32 seqno)
>  }
>  
>  int
> -i915_gem_get_seqno(struct drm_device *dev, u32 *seqno)
> +i915_gem_prepare_next_seqno(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  
>  	/* reserve 0 for non-seqno */
>  	if (dev_priv->next_seqno == 0) {
> +		/* Why is the full re-initialisation required? Is it only for
> +		 * hardware semaphores? If so, could skip it in the case where
> +		 * semaphores are disabled? */
>  		int ret = i915_gem_init_seqno(dev, 0);
>  		if (ret)
>  			return ret;
> @@ -2323,6 +2326,24 @@ i915_gem_get_seqno(struct drm_device *dev, u32 *seqno)
>  		dev_priv->next_seqno = 1;
>  	}
>  
> +	return 0;
> +}
> +
> +static int
> +i915_gem_get_seqno(struct drm_device *dev, u32 *seqno)
> +{
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +	/* reserve 0 for non-seqno */
> +	if (dev_priv->next_seqno == 0) {
> +		/* Should never get here! Must always call 'prepare_next' in
> +		 * advance. This code is called during request submission.
> +		 * Trying to wrap the seqno and the implicit idle() calls that
> +		 * the wrap code makes are a bad idea at this point! */
> +		DRM_ERROR("Need to wrap seqno at inopportune moment!\n");
> +		return -EBUSY;
> +	}
> +
>  	*seqno = dev_priv->last_seqno = dev_priv->next_seqno++;
>  	return 0;
>  }
> @@ -2366,6 +2387,11 @@ int __i915_add_request(struct intel_engine_cs *ring,
>  			return ret;
>  	}
>  
> +	/* Assign an identifier to track this request through the hardware: */
> +	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
> +	if (ret)
> +		return ret;
> +
>  	/* Record the position of the start of the request so that
>  	 * should we detect the updated seqno part-way through the
>  	 * GPU processing the request, we never over-estimate the
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index 5a75eb5..e7d4d20 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -802,6 +802,10 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring,
>  	if (ring->outstanding_lazy_request)
>  		return 0;
>  
> +	ret = i915_gem_prepare_next_seqno(ring->dev);
> +	if (ret)
> +		return ret;
> +
>  	request = kzalloc(sizeof(*request), GFP_KERNEL);
>  	if (request == NULL)
>  		return -ENOMEM;
> @@ -809,12 +813,6 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring,
>  	kref_init(&request->ref);
>  	request->ring = ring;
>  
> -	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
> -	if (ret) {
> -		kfree(request);
> -		return ret;
> -	}
> -
>  	/* Hold a reference to the context this request belongs to
>  	 * (we will need it when the time comes to emit/retire the
>  	 * request).
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 0f2719d..6a2f25d 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -2017,6 +2017,10 @@ intel_ring_alloc_request(struct intel_engine_cs *ring)
>  	if (ring->outstanding_lazy_request)
>  		return 0;
>  
> +	ret = i915_gem_prepare_next_seqno(ring->dev);
> +	if (ret)
> +		return ret;
> +
>  	request = kzalloc(sizeof(*request), GFP_KERNEL);
>  	if (request == NULL)
>  		return -ENOMEM;
> @@ -2024,12 +2028,6 @@ intel_ring_alloc_request(struct intel_engine_cs *ring)
>  	kref_init(&request->ref);
>  	request->ring = ring;
>  
> -	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
> -	if (ret) {
> -		kfree(request);
> -		return ret;
> -	}
> -
>  	ring->outstanding_lazy_request = request;
>  	return 0;
>  }
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 00/21] Replace seqno values with request structures

[Daniel Vetter]

On Fri, Oct 10, 2014 at 01:03:17PM +0100, John Harrison wrote:
> I have just posted an updated subset of the patch series. Note that one
> patch has been inserted in the middle and the first one has been dropped.
> The correct sequence is now:
> 
>    01    drm/i915: Remove redundant parameter to
>    i915_gem_object_wait_rendering__tail()
>    02    drm/i915: Ensure OLS & PLR are always in sync
>    03    drm/i915: Add reference count to request structure
>    04    drm/i915: Add helper functions to aid seqno -> request transition
>    05    drm/i915: Replace last_[rwf]_seqno with last_[rwf]_req
>    06    drm/i915: Ensure requests stick around during waits
>    07    drm/i915: Remove 'outstanding_lazy_seqno'
>    08    drm/i915: Make 'i915_gem_check_olr' actually check by request
>    not seqno
>    09    drm/i915: Convert 'last_flip_req' to be a request not a seqno
>    10    drm/i915: Convert i915_wait_seqno to i915_wait_request
>    11    drm/i915: Convert 'i915_add_request' to take a request not a seqno
>    12    drm/i915: Convert mmio_flip::seqno to struct request
>    13    drm/i915: Convert 'flip_queued_seqno' into 'flip_queued_request'
>    14    drm/i915: Connect requests to rings at creation not submission
>    15    drm/i915: Convert most 'i915_seqno_passed' calls into
>    'i915_gem_request_completed'
>    16    drm/i915: Convert __wait_seqno() to __wait_request()
>    17    drm/i915: Convert trace functions from seqno to request
>    18    drm/i915: Convert 'trace_irq' to use requests rather than seqnos
>    19    drm/i915: Convert semaphores to handle requests not seqnos
>    20    drm/i915: Convert 'ring_idle()' to use requests not seqnos
>    21    drm/i915: Remove 'obj->ring'
>    22    drm/i915: Cache request completion status
>    23    drm/i915: Zero fill the request structure
>    24    drm/i915: Defer seqno allocation until actual hardware
>    submission time
> 
> 
> The whole set in its latest and greatest form has also been uploaded to the
> drm-private git as 'topic/seqno-request'.

Ok, read through the entire pile and looks good from a high level I think.
Review summary is really just "please less BUG_ON and more commit
message". I think even the few funky things can probably just be explained
away with a good commit message.

That aside I think even for RFC the commit message really should be there,
since that's what I need to be able to efficiently review patches. If the
series is littered with FIXME comments all over that's ok (that's what an
rfc is for really), but the justifications and tricky points should all be
there. So I highly recommend to self-review patch series (using the review
training slides) even for an rfc to make sure there's not too many bubbles
in the pipeline.

Presuming there's no dragon hidden in any of the open issues I'll sign up
someone else for the in-depth review.

Cheers, Daniel

> 
> 
> On 06/10/2014 15:15, John.C.Harrison@Intel.com wrote:
> >From: John Harrison <John.C.Harrison@Intel.com>
> >
> >Work in progress for replacing seqno usage with requst structures.
> >
> >There is a general feeling that it is better to move away from using a simple
> >integer 'seqno' value to track batch buffer completion. Instead, the request
> >structure should be used. That provides for much more flexibility going
> >forwards. Especially which things like a GPU scheduler (which can re-order batch
> >buffers and hence seqnos after submission to the hardware), Android sync points
> >and other such features which potentially make seqno usage more and more
> >complex.
> >
> >The current set of patches do most of the seqno to request structure conversion.
> >There are still a couple of direct seqno comparisons in the semaphore code. The
> >final conversion of a seqno test into a 'completed' flag inside the request
> >structure is still do to as well. Along with whatever changes are required to
> >maintain such a flag.
> >
> >The patches are being posted now to make sure that the various people involved
> >agree that it is heading in the right direction.
> >
> >[Patches against drm-intel-nightly tree fetched 11/09/2014]
> >
> >John Harrison (21):
> >   Bug: missing i915_seqno_passed() call?
> >   drm/i915: Remove redundant parameter to i915_gem_object_wait_rendering__tail()
> >   drm/i915: Ensure OLS & PLR are always in sync
> >   drm/i915: Add reference count to request structure
> >   drm/i915: Add helper functions to aid seqno -> request transition
> >   drm/i915: Replace last_[rwf]_seqno with last_[rwf]_req
> >   drm/i915: Ensure requests stick around during waits
> >   drm/i915: Remove 'outstanding_lazy_seqno'
> >   drm/i915: Make 'i915_gem_check_olr' actually check by request not seqno
> >   drm/i915: Convert 'last_flip_req' to be a request not a seqno
> >   drm/i915: Convert i915_wait_seqno to i915_wait_request
> >   drm/i915: Convert 'i915_add_request' to take a request not a seqno
> >   drm/i915: Convert mmio_flip::seqno to struct request
> >   drm/i915: Convert 'flip_queued_seqno' into 'flip_queued_request'
> >   drm/i915: Convert most 'i915_seqno_passed' calls into 'i915_gem_request_completed'
> >   drm/i915: Convert __wait_seqno() to __wait_request()
> >   drm/i915: Convert trace functions from seqno to request
> >   drm/i915: Convert 'trace_irq' to use requests rather than seqnos
> >   drm/i915: Convert semaphores to handle requests not seqnos
> >   drm/i915: Convert 'ring_idle()' to use requests not seqnos
> >   drm/i915: Remove 'obj->ring'
> >
> >  drivers/gpu/drm/i915/i915_debugfs.c        |   23 +--
> >  drivers/gpu/drm/i915/i915_drv.h            |   64 +++++--
> >  drivers/gpu/drm/i915/i915_gem.c            |  265 ++++++++++++++--------------
> >  drivers/gpu/drm/i915/i915_gem_context.c    |   12 +-
> >  drivers/gpu/drm/i915/i915_gem_execbuffer.c |    8 +-
> >  drivers/gpu/drm/i915/i915_gem_gtt.h        |    4 +-
> >  drivers/gpu/drm/i915/i915_gem_tiling.c     |    2 +-
> >  drivers/gpu/drm/i915/i915_gpu_error.c      |   19 +-
> >  drivers/gpu/drm/i915/i915_irq.c            |   12 +-
> >  drivers/gpu/drm/i915/i915_trace.h          |   47 ++---
> >  drivers/gpu/drm/i915/intel_display.c       |   47 ++---
> >  drivers/gpu/drm/i915/intel_drv.h           |    4 +-
> >  drivers/gpu/drm/i915/intel_lrc.c           |   49 ++---
> >  drivers/gpu/drm/i915/intel_overlay.c       |   17 +-
> >  drivers/gpu/drm/i915/intel_ringbuffer.c    |   88 +++++----
> >  drivers/gpu/drm/i915/intel_ringbuffer.h    |   24 ++-
> >  16 files changed, 392 insertions(+), 293 deletions(-)
> >
> 

> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx


-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 00/21] Replace seqno values with request structures

[Daniel Vetter]

On Mon, Oct 6, 2014 at 5:17 PM, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> On Mon, Oct 06, 2014 at 03:15:04PM +0100, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
>>
>> Work in progress for replacing seqno usage with requst structures.
>
> You fail to end up with my earlier code. Nak.

Well I've tried to split up your patch into small independent changes
and failed at that. And given how many changes there are in there I
simply can't merge your patch as-is. I know that it does seem to fix
some random hangs, but with massive behaviour changes like the
read-read stuff in there this could very well just be a random fluke.

But if there's anything amiss in John's work for the plain
s/seqno/request/ change, or anything else that we absolutely need to
have then I very much want your opinion on this. But a flat outright
nak without further content isn't useful to move forward.

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 00/21] Replace seqno values with request structures

[Chris Wilson]

On Sun, Oct 19, 2014 at 07:15:53PM +0200, Daniel Vetter wrote:
> On Mon, Oct 6, 2014 at 5:17 PM, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > On Mon, Oct 06, 2014 at 03:15:04PM +0100, John.C.Harrison@Intel.com wrote:
> >> From: John Harrison <John.C.Harrison@Intel.com>
> >>
> >> Work in progress for replacing seqno usage with requst structures.
> >
> > You fail to end up with my earlier code. Nak.
> 
> Well I've tried to split up your patch into small independent changes
> and failed at that. And given how many changes there are in there I
> simply can't merge your patch as-is. I know that it does seem to fix
> some random hangs, but with massive behaviour changes like the
> read-read stuff in there this could very well just be a random fluke.

Nope. Try reading it again. The most invasive change is defining the
order of engine/context/ppgtt/ring creation (and doing the setup/enable
split). Everything else is about making a request a transaction and
using that to fix bugs in our state tacking.

The fundamental change, that I am going to be a stickler for, is that the
request is the ring access. It defines the context, owner and interface
to both the ring and the engine/scheduler. In doing so it drops the
inconsistent and unmaintainable approach of introducing separate but almost
duplicate code paths inside the core of GEM.
 
> But if there's anything amiss in John's work for the plain
> s/seqno/request/ change, or anything else that we absolutely need to
> have then I very much want your opinion on this. But a flat outright
> nak without further content isn't useful to move forward.

It doesn't reduce the technical debt of execlists, which was the
motivation for the changes. It even brings a breath of sanity to
contexts and ppgtt as well, a massive boon.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre

Re: [RFC 00/21] Replace seqno values with request structures

[John Harrison]

On 19/10/2014 15:21, Daniel Vetter wrote:
> On Fri, Oct 10, 2014 at 01:03:17PM +0100, John Harrison wrote:
>> I have just posted an updated subset of the patch series. Note that one
>> patch has been inserted in the middle and the first one has been dropped.
>> The correct sequence is now:
>>
>>     01    drm/i915: Remove redundant parameter to
>>     i915_gem_object_wait_rendering__tail()
>>     02    drm/i915: Ensure OLS & PLR are always in sync
>>     03    drm/i915: Add reference count to request structure
>>     04    drm/i915: Add helper functions to aid seqno -> request transition
>>     05    drm/i915: Replace last_[rwf]_seqno with last_[rwf]_req
>>     06    drm/i915: Ensure requests stick around during waits
>>     07    drm/i915: Remove 'outstanding_lazy_seqno'
>>     08    drm/i915: Make 'i915_gem_check_olr' actually check by request
>>     not seqno
>>     09    drm/i915: Convert 'last_flip_req' to be a request not a seqno
>>     10    drm/i915: Convert i915_wait_seqno to i915_wait_request
>>     11    drm/i915: Convert 'i915_add_request' to take a request not a seqno
>>     12    drm/i915: Convert mmio_flip::seqno to struct request
>>     13    drm/i915: Convert 'flip_queued_seqno' into 'flip_queued_request'
>>     14    drm/i915: Connect requests to rings at creation not submission
>>     15    drm/i915: Convert most 'i915_seqno_passed' calls into
>>     'i915_gem_request_completed'
>>     16    drm/i915: Convert __wait_seqno() to __wait_request()
>>     17    drm/i915: Convert trace functions from seqno to request
>>     18    drm/i915: Convert 'trace_irq' to use requests rather than seqnos
>>     19    drm/i915: Convert semaphores to handle requests not seqnos
>>     20    drm/i915: Convert 'ring_idle()' to use requests not seqnos
>>     21    drm/i915: Remove 'obj->ring'
>>     22    drm/i915: Cache request completion status
>>     23    drm/i915: Zero fill the request structure
>>     24    drm/i915: Defer seqno allocation until actual hardware
>>     submission time
>>
>>
>> The whole set in its latest and greatest form has also been uploaded to the
>> drm-private git as 'topic/seqno-request'.
> Ok, read through the entire pile and looks good from a high level I think.
> Review summary is really just "please less BUG_ON and more commit
> message". I think even the few funky things can probably just be explained
> away with a good commit message.
A few of the BUG_ONs disappear again along the way and others are just 
converting existing BUG_ONs from seqnos to requests.

The minimal messaging was because the intention was to get something 
posted as soon as possible in order to be reviewed as soon as possible 
if only from a 'is this what you had in mind' point of view. I didn't 
realise you were going to be out of office for so long. There didn't 
seem much value in writing reams of description only to be told a day 
later that I've misunderstood your design spec and gone off in 
completely the wrong direction.


> That aside I think even for RFC the commit message really should be there,
> since that's what I need to be able to efficiently review patches. If the
> series is littered with FIXME comments all over that's ok (that's what an
> rfc is for really), but the justifications and tricky points should all be
> there. So I highly recommend to self-review patch series (using the review
> training slides) even for an rfc to make sure there's not too many bubbles
> in the pipeline.
>
> Presuming there's no dragon hidden in any of the open issues I'll sign up
> someone else for the in-depth review.
>
> Cheers, Daniel
>
>>
>> On 06/10/2014 15:15, John.C.Harrison@Intel.com wrote:
>>> From: John Harrison <John.C.Harrison@Intel.com>
>>>
>>> Work in progress for replacing seqno usage with requst structures.
>>>
>>> There is a general feeling that it is better to move away from using a simple
>>> integer 'seqno' value to track batch buffer completion. Instead, the request
>>> structure should be used. That provides for much more flexibility going
>>> forwards. Especially which things like a GPU scheduler (which can re-order batch
>>> buffers and hence seqnos after submission to the hardware), Android sync points
>>> and other such features which potentially make seqno usage more and more
>>> complex.
>>>
>>> The current set of patches do most of the seqno to request structure conversion.
>>> There are still a couple of direct seqno comparisons in the semaphore code. The
>>> final conversion of a seqno test into a 'completed' flag inside the request
>>> structure is still do to as well. Along with whatever changes are required to
>>> maintain such a flag.
>>>
>>> The patches are being posted now to make sure that the various people involved
>>> agree that it is heading in the right direction.
>>>
>>> [Patches against drm-intel-nightly tree fetched 11/09/2014]
>>>
>>> John Harrison (21):
>>>    Bug: missing i915_seqno_passed() call?
>>>    drm/i915: Remove redundant parameter to i915_gem_object_wait_rendering__tail()
>>>    drm/i915: Ensure OLS & PLR are always in sync
>>>    drm/i915: Add reference count to request structure
>>>    drm/i915: Add helper functions to aid seqno -> request transition
>>>    drm/i915: Replace last_[rwf]_seqno with last_[rwf]_req
>>>    drm/i915: Ensure requests stick around during waits
>>>    drm/i915: Remove 'outstanding_lazy_seqno'
>>>    drm/i915: Make 'i915_gem_check_olr' actually check by request not seqno
>>>    drm/i915: Convert 'last_flip_req' to be a request not a seqno
>>>    drm/i915: Convert i915_wait_seqno to i915_wait_request
>>>    drm/i915: Convert 'i915_add_request' to take a request not a seqno
>>>    drm/i915: Convert mmio_flip::seqno to struct request
>>>    drm/i915: Convert 'flip_queued_seqno' into 'flip_queued_request'
>>>    drm/i915: Convert most 'i915_seqno_passed' calls into 'i915_gem_request_completed'
>>>    drm/i915: Convert __wait_seqno() to __wait_request()
>>>    drm/i915: Convert trace functions from seqno to request
>>>    drm/i915: Convert 'trace_irq' to use requests rather than seqnos
>>>    drm/i915: Convert semaphores to handle requests not seqnos
>>>    drm/i915: Convert 'ring_idle()' to use requests not seqnos
>>>    drm/i915: Remove 'obj->ring'
>>>
>>>   drivers/gpu/drm/i915/i915_debugfs.c        |   23 +--
>>>   drivers/gpu/drm/i915/i915_drv.h            |   64 +++++--
>>>   drivers/gpu/drm/i915/i915_gem.c            |  265 ++++++++++++++--------------
>>>   drivers/gpu/drm/i915/i915_gem_context.c    |   12 +-
>>>   drivers/gpu/drm/i915/i915_gem_execbuffer.c |    8 +-
>>>   drivers/gpu/drm/i915/i915_gem_gtt.h        |    4 +-
>>>   drivers/gpu/drm/i915/i915_gem_tiling.c     |    2 +-
>>>   drivers/gpu/drm/i915/i915_gpu_error.c      |   19 +-
>>>   drivers/gpu/drm/i915/i915_irq.c            |   12 +-
>>>   drivers/gpu/drm/i915/i915_trace.h          |   47 ++---
>>>   drivers/gpu/drm/i915/intel_display.c       |   47 ++---
>>>   drivers/gpu/drm/i915/intel_drv.h           |    4 +-
>>>   drivers/gpu/drm/i915/intel_lrc.c           |   49 ++---
>>>   drivers/gpu/drm/i915/intel_overlay.c       |   17 +-
>>>   drivers/gpu/drm/i915/intel_ringbuffer.c    |   88 +++++----
>>>   drivers/gpu/drm/i915/intel_ringbuffer.h    |   24 ++-
>>>   16 files changed, 392 insertions(+), 293 deletions(-)
>>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>

Re: [RFC 03/21] drm/i915: Ensure OLS & PLR are always in sync

[John Harrison]

On 19/10/2014 13:32, Daniel Vetter wrote:
> On Mon, Oct 06, 2014 at 03:15:07PM +0100, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
>>
>> The new seqno alloction code pre-allocates a 'lazy' request structure and then
>> tries to allocate the 'lazy' seqno. The seqno allocation can potential wrap
>> around zero and when doing so, tries to idle the ring by waiting for all
>> oustanding work to complete. With a scheduler in place, this can mean first
>> submitting extra work to the ring. However, at this point in time, the lazy
>> request is valid but the lazy seqno is not. Some existing code was getting
>> confused by this state and Bad Things would happen.
> I'm confused about this description. I think you need to go into more
> detail about what exactly you mean with "new seqno allocation code" (does
> this reference some future patches), "confused state" and "Bad Things".
>
> I get a bit the impression that this is just a bad interaction between the
> scheduler and the seqno wrapping. Which might be due to allocating the
> seqno too early when the scheduler it active. So if that's the case then
> imo this shouldn't be in the s/seqno/request/ prep work series.

This patch was originally part of the scheduler set. However, it made 
sense to pull this in earlier as part of this patch set as a safer step 
in the shift of focus from seqno to request. I didn't get around to 
updating the description for the new location. However, it might be 
simpler to not bother with this change and just jump straight to 
removing the seqno completely.

The Bad Things were either null pointer derefences when code used a null 
lazy request having only checked for the presence of a lazy seqno, or 
possibly attempting to process a zero seqno having only checked for the 
presence of a lazy request. The former was a kernel panic, the latter a 
silent failure to synchronise properly.

>> The safest solution is to still allocate the lazy request in advance (to avoid
>> having to roll back in an out of memory sitation) but to save the pointer in a
>> local variable rather than immediately updating the lazy pointer. Only after a
>> valid seqno has been acquired is the lazy request pointer actually updated.
>>
>> This guarantees that both lazy values are either invalid or both valid. There
>> can no longer be an inconsistent state.
>>
>> For: VIZ-4377
>> Signed-off-by: John.C.Harrison@Intel.com
>> ---
>>   drivers/gpu/drm/i915/intel_lrc.c        |   42 ++++++++++++++++++++-----------
>>   drivers/gpu/drm/i915/intel_ringbuffer.c |   29 +++++++++++++++------
>>   2 files changed, 48 insertions(+), 23 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
>> index bafd38b..3ac2622 100644
>> --- a/drivers/gpu/drm/i915/intel_lrc.c
>> +++ b/drivers/gpu/drm/i915/intel_lrc.c
>> @@ -796,27 +796,39 @@ void intel_logical_ring_advance_and_submit(struct intel_ringbuffer *ringbuf)
>>   static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
>>   				    struct intel_context *ctx)
>>   {
>> -	if (ring->outstanding_lazy_seqno)
>> -		return 0;
>> +	struct drm_i915_gem_request *request;
>> +	int ret;
>>   
>> -	if (ring->preallocated_lazy_request == NULL) {
>> -		struct drm_i915_gem_request *request;
>> +	/* The aim is to replace seqno values with request structures. A step
>> +	 * along the way is to switch to using the PLR in preference to the
>> +	 * OLS. That requires the PLR to only be valid when the OLS is also
>> +	 * valid. I.e., the two must be kept in step. */
>>   
>> -		request = kmalloc(sizeof(*request), GFP_KERNEL);
>> -		if (request == NULL)
>> -			return -ENOMEM;
>> +	if (ring->outstanding_lazy_seqno) {
>> +		BUG_ON(ring->preallocated_lazy_request == NULL);
> Too many BUG_ON in this patch. This one here can easily be avoided with a
> if (WARN_ON) retrun -EIO; or so, the below one would just indicate a leak
> so a plain WARN_ON is good enough.
>
> BUG_ON makes it a major pain to debug anything out there in the field, so
> the barrier to acceptance is really high.
These BUG_ONs are purely temporary. They disappear when the seqno itself 
is removed and the function becomes '..._alloc_request()'.
>> +		return 0;
>> +	}
>> +	BUG_ON(ring->preallocated_lazy_request != NULL);
>>   
>> -		/* Hold a reference to the context this request belongs to
>> -		 * (we will need it when the time comes to emit/retire the
>> -		 * request).
>> -		 */
>> -		request->ctx = ctx;
>> -		i915_gem_context_reference(request->ctx);
>> +	request = kmalloc(sizeof(*request), GFP_KERNEL);
>> +	if (request == NULL)
>> +		return -ENOMEM;
>>   
>> -		ring->preallocated_lazy_request = request;
>> +	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
>> +	if (ret) {
>> +		kfree(request);
>> +		return ret;
>>   	}
>>   
>> -	return i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
>> +	/* Hold a reference to the context this request belongs to
>> +	 * (we will need it when the time comes to emit/retire the
>> +	 * request).
>> +	 */
>> +	request->ctx = ctx;
>> +	i915_gem_context_reference(request->ctx);
>> +
>> +	ring->preallocated_lazy_request = request;
>> +	return 0;
>>   }
>>   
>>   static int logical_ring_wait_request(struct intel_ringbuffer *ringbuf,
>> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
>> index 25795f2..cceac67 100644
>> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
>> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
>> @@ -2000,20 +2000,33 @@ int intel_ring_idle(struct intel_engine_cs *ring)
>>   static int
>>   intel_ring_alloc_seqno(struct intel_engine_cs *ring)
>>   {
>> -	if (ring->outstanding_lazy_seqno)
>> +	int ret;
>> +	struct drm_i915_gem_request *request;
>> +
>> +	/* The aim is to replace seqno values with request structures. A step
>> +	 * along the way is to switch to using the PLR in preference to the
>> +	 * OLS. That requires the PLR to only be valid when the OLS is also
>> +	 * valid. I.e., the two must be kept in step. */
>> +
>> +	if (ring->outstanding_lazy_seqno) {
>> +		BUG_ON(ring->preallocated_lazy_request == NULL);
>>   		return 0;
>> +	}
>>   
>> -	if (ring->preallocated_lazy_request == NULL) {
>> -		struct drm_i915_gem_request *request;
>> +	BUG_ON(ring->preallocated_lazy_request != NULL);
>>   
>> -		request = kmalloc(sizeof(*request), GFP_KERNEL);
>> -		if (request == NULL)
>> -			return -ENOMEM;
>> +	request = kmalloc(sizeof(*request), GFP_KERNEL);
>> +	if (request == NULL)
>> +		return -ENOMEM;
>>   
>> -		ring->preallocated_lazy_request = request;
>> +	ret = i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
>> +	if (ret) {
>> +		kfree(request);
>> +		return ret;
>>   	}
>>   
>> -	return i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_seqno);
>> +	ring->preallocated_lazy_request = request;
>> +	return 0;
>>   }
>>   
>>   static int __intel_ring_prepare(struct intel_engine_cs *ring,
>> -- 
>> 1.7.9.5
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [RFC 05/21] drm/i915: Add helper functions to aid seqno -> request transition

[John Harrison]

On 19/10/2014 13:35, Daniel Vetter wrote:
> On Mon, Oct 06, 2014 at 03:15:09PM +0100, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
>>
> I think a few words about how these helpers help the transitions (and
> example maybe) would be great. Since without peeking ahead (which I
> didn't) and looking at the JIRA (which I've forgotten all about already
> right after writing it) this doesn't make a lot of sense ;-)
>
>> For: VIZ-4377
>> Signed-off-by: John.C.Harrison@Intel.com
>> ---
>>   drivers/gpu/drm/i915/i915_drv.h         |   12 ++++++++++++
>>   drivers/gpu/drm/i915/intel_ringbuffer.h |    7 +++++++
>>   2 files changed, 19 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index e1858e7..62c9f66 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -1946,6 +1946,18 @@ struct drm_i915_gem_request {
>>   
>>   void i915_gem_request_free(struct kref *req_ref);
>>   
>> +static inline uint32_t
>> +i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
>> +{
>> +	return req ? req->seqno : 0;
>> +}
>> +
>> +static inline struct intel_engine_cs *
>> +i915_gem_request_get_ring(struct drm_i915_gem_request *req)
>> +{
>> +	return req ? req->ring : NULL;
>> +}
>> +
>>   static inline void
>>   i915_gem_request_reference(struct drm_i915_gem_request *req)
>>   {
>> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
>> index 96479c8..cc1b62f 100644
>> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
>> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
>> @@ -435,6 +435,13 @@ static inline u32 intel_ring_get_seqno(struct intel_engine_cs *ring)
>>   	return ring->outstanding_lazy_seqno;
>>   }
>>   
>> +static inline struct drm_i915_gem_request *
>> +intel_ring_get_request(struct intel_engine_cs *ring)
>> +{
>> +	BUG_ON(ring->preallocated_lazy_request == NULL);
> Again, I'm not a fan of BUG_ON. But if this is just a transitional thing
> and will disappear at the end of the series I'm ok with it.
> -Daniel
I just copied the existing 'intel_ring_get_seqno()' function and 
replaced 'seqno' with 'request'. The outgoing existing code has a BUG_ON 
therefore it seemed sensible to include a BUG_ON in the incoming new code.

>> +	return ring->preallocated_lazy_request;
>> +}
>> +
>>   static inline void i915_trace_irq_get(struct intel_engine_cs *ring, u32 seqno)
>>   {
>>   	if (ring->trace_irq_seqno == 0 && ring->irq_get(ring))
>> -- 
>> 1.7.9.5
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [RFC 00/21] Replace seqno values with request structures

[Daniel Vetter]

On Mon, Oct 20, 2014 at 11:19:28AM +0100, John Harrison wrote:
> On 19/10/2014 15:21, Daniel Vetter wrote:
> >On Fri, Oct 10, 2014 at 01:03:17PM +0100, John Harrison wrote:
> >>I have just posted an updated subset of the patch series. Note that one
> >>patch has been inserted in the middle and the first one has been dropped.
> >>The correct sequence is now:
> >>
> >>    01    drm/i915: Remove redundant parameter to
> >>    i915_gem_object_wait_rendering__tail()
> >>    02    drm/i915: Ensure OLS & PLR are always in sync
> >>    03    drm/i915: Add reference count to request structure
> >>    04    drm/i915: Add helper functions to aid seqno -> request transition
> >>    05    drm/i915: Replace last_[rwf]_seqno with last_[rwf]_req
> >>    06    drm/i915: Ensure requests stick around during waits
> >>    07    drm/i915: Remove 'outstanding_lazy_seqno'
> >>    08    drm/i915: Make 'i915_gem_check_olr' actually check by request
> >>    not seqno
> >>    09    drm/i915: Convert 'last_flip_req' to be a request not a seqno
> >>    10    drm/i915: Convert i915_wait_seqno to i915_wait_request
> >>    11    drm/i915: Convert 'i915_add_request' to take a request not a seqno
> >>    12    drm/i915: Convert mmio_flip::seqno to struct request
> >>    13    drm/i915: Convert 'flip_queued_seqno' into 'flip_queued_request'
> >>    14    drm/i915: Connect requests to rings at creation not submission
> >>    15    drm/i915: Convert most 'i915_seqno_passed' calls into
> >>    'i915_gem_request_completed'
> >>    16    drm/i915: Convert __wait_seqno() to __wait_request()
> >>    17    drm/i915: Convert trace functions from seqno to request
> >>    18    drm/i915: Convert 'trace_irq' to use requests rather than seqnos
> >>    19    drm/i915: Convert semaphores to handle requests not seqnos
> >>    20    drm/i915: Convert 'ring_idle()' to use requests not seqnos
> >>    21    drm/i915: Remove 'obj->ring'
> >>    22    drm/i915: Cache request completion status
> >>    23    drm/i915: Zero fill the request structure
> >>    24    drm/i915: Defer seqno allocation until actual hardware
> >>    submission time
> >>
> >>
> >>The whole set in its latest and greatest form has also been uploaded to the
> >>drm-private git as 'topic/seqno-request'.
> >Ok, read through the entire pile and looks good from a high level I think.
> >Review summary is really just "please less BUG_ON and more commit
> >message". I think even the few funky things can probably just be explained
> >away with a good commit message.
> A few of the BUG_ONs disappear again along the way and others are just
> converting existing BUG_ONs from seqnos to requests.

Yeah, there's a bunch of preexisting ones that I've let slip through. But
I've screamed at a BUG_ON that killed my machine once too often in the
past few months, so I've started to be really strict about them. If
they're just temporary then a WARN_ON should be about as informative, or
just drop them since if a pointer is NULL you'll blow up anyway a few
instructions later with an Oops.

> The minimal messaging was because the intention was to get something posted
> as soon as possible in order to be reviewed as soon as possible if only from
> a 'is this what you had in mind' point of view. I didn't realise you were
> going to be out of office for so long. There didn't seem much value in
> writing reams of description only to be told a day later that I've
> misunderstood your design spec and gone off in completely the wrong
> direction.

Oh, I guess then I've looked too closely at it ;-) From the high-level
point it's pretty much what I expected, so lgtm.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 00/21] Replace seqno values with request structures

[Daniel Vetter]

On Mon, Oct 20, 2014 at 08:19:18AM +0100, Chris Wilson wrote:
> On Sun, Oct 19, 2014 at 07:15:53PM +0200, Daniel Vetter wrote:
> > On Mon, Oct 6, 2014 at 5:17 PM, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > > On Mon, Oct 06, 2014 at 03:15:04PM +0100, John.C.Harrison@Intel.com wrote:
> > >> From: John Harrison <John.C.Harrison@Intel.com>
> > >>
> > >> Work in progress for replacing seqno usage with requst structures.
> > >
> > > You fail to end up with my earlier code. Nak.
> > 
> > Well I've tried to split up your patch into small independent changes
> > and failed at that. And given how many changes there are in there I
> > simply can't merge your patch as-is. I know that it does seem to fix
> > some random hangs, but with massive behaviour changes like the
> > read-read stuff in there this could very well just be a random fluke.
> 
> Nope. Try reading it again. The most invasive change is defining the
> order of engine/context/ppgtt/ring creation (and doing the setup/enable
> split). Everything else is about making a request a transaction and
> using that to fix bugs in our state tacking.

I guess the setup changes only showed up in the revised and much bigger
version. At least I don't remember seeing that in the first iteration I've
tried to split up. Or maybe I've been blind. In any case I want to
untangle that web too, just with a much more gradual approach.
 
> The fundamental change, that I am going to be a stickler for, is that the
> request is the ring access. It defines the context, owner and interface
> to both the ring and the engine/scheduler. In doing so it drops the
> inconsistent and unmaintainable approach of introducing separate but almost
> duplicate code paths inside the core of GEM.

So for a clean slate design I agree with you. But given where we are I
still think that the duplication with the execlist code in intel_lrc.c is
a good approach. It will lead to a lot more ugliness, and there's a good
chance that we can't get rid of the final bits in years. But given that
execlist absolutely had to get in I really didn't see any other way to
merge it, without the inevitable reworks totally wreaking the other parts
of gem.

It's definitely not a great option, but there's also limits to how much
flak I can absorb without crumbling completely.

> > But if there's anything amiss in John's work for the plain
> > s/seqno/request/ change, or anything else that we absolutely need to
> > have then I very much want your opinion on this. But a flat outright
> > nak without further content isn't useful to move forward.
> 
> It doesn't reduce the technical debt of execlists, which was the
> motivation for the changes. It even brings a breath of sanity to
> contexts and ppgtt as well, a massive boon.

I agree on that. It should give us a start though to clean things up by
shifting a lot tracking execlist does over to requests. Or at least I hope
so. And there's still the issue that I really need to avoid another dept
pile-up excercise with the scheduler, so for just that part I think we
need this. Even when it doesn't address any of the issues with execlist.
But I do think this will allow us to at least move into the right
direction a bit, so please scream if I'm totally off the tracks.

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [RFC 06/21] drm/i915: Replace last_[rwf]_seqno with last_[rwf]_req

[John Harrison]

On 19/10/2014 13:40, Daniel Vetter wrote:
> On Mon, Oct 06, 2014 at 03:15:10PM +0100, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
>>
>> For: VIZ-4377
>> Signed-off-by: John.C.Harrison@Intel.com
>> ---
>>   drivers/gpu/drm/i915/i915_debugfs.c        |    6 +--
>>   drivers/gpu/drm/i915/i915_drv.h            |    6 +--
>>   drivers/gpu/drm/i915/i915_gem.c            |   66 ++++++++++++++++------------
>>   drivers/gpu/drm/i915/i915_gem_execbuffer.c |    6 +--
>>   drivers/gpu/drm/i915/i915_gem_gtt.h        |    4 +-
>>   drivers/gpu/drm/i915/i915_gem_tiling.c     |    2 +-
>>   drivers/gpu/drm/i915/i915_gpu_error.c      |    4 +-
>>   drivers/gpu/drm/i915/intel_display.c       |   10 ++---
>>   drivers/gpu/drm/i915/intel_ringbuffer.h    |    2 +-
>>   9 files changed, 58 insertions(+), 48 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
>> index 063b448..726a8f0 100644
>> --- a/drivers/gpu/drm/i915/i915_debugfs.c
>> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
>> @@ -133,9 +133,9 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj)
>>   		   obj->base.size / 1024,
>>   		   obj->base.read_domains,
>>   		   obj->base.write_domain,
>> -		   obj->last_read_seqno,
>> -		   obj->last_write_seqno,
>> -		   obj->last_fenced_seqno,
>> +		   i915_gem_request_get_seqno(obj->last_read_req),
>> +		   i915_gem_request_get_seqno(obj->last_write_req),
>> +		   i915_gem_request_get_seqno(obj->last_fenced_req),
>>   		   i915_cache_level_str(to_i915(obj->base.dev), obj->cache_level),
>>   		   obj->dirty ? " dirty" : "",
>>   		   obj->madv == I915_MADV_DONTNEED ? " purgeable" : "");
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 62c9f66..1401266 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -1862,10 +1862,10 @@ struct drm_i915_gem_object {
>>   	struct intel_engine_cs *ring;
>>   
>>   	/** Breadcrumb of last rendering to the buffer. */
>> -	uint32_t last_read_seqno;
>> -	uint32_t last_write_seqno;
>> +	struct drm_i915_gem_request *last_read_req;
>> +	struct drm_i915_gem_request *last_write_req;
>>   	/** Breadcrumb of last fenced GPU access to the buffer. */
>> -	uint32_t last_fenced_seqno;
>> +	struct drm_i915_gem_request *last_fenced_req;
>>   
>>   	/** Current tiling stride for the object, if it's tiled. */
>>   	uint32_t stride;
>> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
>> index 2555cd8..2c33a83 100644
>> --- a/drivers/gpu/drm/i915/i915_gem.c
>> +++ b/drivers/gpu/drm/i915/i915_gem.c
>> @@ -1289,11 +1289,11 @@ i915_gem_object_wait_rendering__tail(struct drm_i915_gem_object *obj)
>>   	/* Manually manage the write flush as we may have not yet
>>   	 * retired the buffer.
>>   	 *
>> -	 * Note that the last_write_seqno is always the earlier of
>> -	 * the two (read/write) seqno, so if we haved successfully waited,
>> +	 * Note that the last_write_req is always the earlier of
>> +	 * the two (read/write) requests, so if we haved successfully waited,
>>   	 * we know we have passed the last write.
>>   	 */
>> -	obj->last_write_seqno = 0;
>> +	obj->last_write_req = NULL;
>>   
>>   	return 0;
>>   }
>> @@ -1306,14 +1306,18 @@ static __must_check int
>>   i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj,
>>   			       bool readonly)
>>   {
>> +	struct drm_i915_gem_request *req;
>>   	struct intel_engine_cs *ring = obj->ring;
>>   	u32 seqno;
>>   	int ret;
>>   
>> -	seqno = readonly ? obj->last_write_seqno : obj->last_read_seqno;
>> -	if (seqno == 0)
>> +	req = readonly ? obj->last_write_req : obj->last_read_req;
>> +	if (!req)
>>   		return 0;
>>   
>> +	seqno = i915_gem_request_get_seqno(req);
>> +	BUG_ON(seqno == 0);
> Again, you like BUG_ON a bit too much for my taste. If you want these
> checks imo a WARN_ON in i915_gem_request_get_seqno (iff req != NULL ofc)
> in the previous patch would be much better.
> -Daniel

Again a) this patch set was posted as a work in progress, I would like 
some quick feedback before attempting to finish it, polish it, flush out 
the corner cases, etc. And for internal development debug, BUG_ONs are a 
lot more use than WARN_ON. And b) this will disappear in a later patch 
when the seqno is removed completely and 'i915_wait_seqno(seqno)' 
becomes 'i915_wait_request(request)'.


>> +
>>   	ret = i915_wait_seqno(ring, seqno);
>>   	if (ret)
>>   		return ret;
>> @@ -1329,6 +1333,7 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
>>   					    struct drm_i915_file_private *file_priv,
>>   					    bool readonly)
>>   {
>> +	struct drm_i915_gem_request *req;
>>   	struct drm_device *dev = obj->base.dev;
>>   	struct drm_i915_private *dev_priv = dev->dev_private;
>>   	struct intel_engine_cs *ring = obj->ring;
>> @@ -1339,10 +1344,13 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
>>   	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
>>   	BUG_ON(!dev_priv->mm.interruptible);
>>   
>> -	seqno = readonly ? obj->last_write_seqno : obj->last_read_seqno;
>> -	if (seqno == 0)
>> +	req = readonly ? obj->last_write_req : obj->last_read_req;
>> +	if (!req)
>>   		return 0;
>>   
>> +	seqno = i915_gem_request_get_seqno(req);
>> +	BUG_ON(seqno == 0);
>> +
>>   	ret = i915_gem_check_wedge(&dev_priv->gpu_error, true);
>>   	if (ret)
>>   		return ret;
>> @@ -2180,12 +2188,12 @@ static void
>>   i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
>>   			       struct intel_engine_cs *ring)
>>   {
>> -	u32 seqno = intel_ring_get_seqno(ring);
>> +	struct drm_i915_gem_request *req = intel_ring_get_request(ring);
>>   
>>   	BUG_ON(ring == NULL);
>> -	if (obj->ring != ring && obj->last_write_seqno) {
>> -		/* Keep the seqno relative to the current ring */
>> -		obj->last_write_seqno = seqno;
>> +	if (obj->ring != ring && obj->last_write_req) {
>> +		/* Keep the request relative to the current ring */
>> +		obj->last_write_req = req;
>>   	}
>>   	obj->ring = ring;
>>   
>> @@ -2197,7 +2205,7 @@ i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
>>   
>>   	list_move_tail(&obj->ring_list, &ring->active_list);
>>   
>> -	obj->last_read_seqno = seqno;
>> +	obj->last_read_req = req;
>>   }
>>   
>>   void i915_vma_move_to_active(struct i915_vma *vma,
>> @@ -2228,11 +2236,11 @@ i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
>>   	list_del_init(&obj->ring_list);
>>   	obj->ring = NULL;
>>   
>> -	obj->last_read_seqno = 0;
>> -	obj->last_write_seqno = 0;
>> +	obj->last_read_req = NULL;
>> +	obj->last_write_req = NULL;
>>   	obj->base.write_domain = 0;
>>   
>> -	obj->last_fenced_seqno = 0;
>> +	obj->last_fenced_req = NULL;
>>   
>>   	obj->active = 0;
>>   	drm_gem_object_unreference(&obj->base);
>> @@ -2249,7 +2257,7 @@ i915_gem_object_retire(struct drm_i915_gem_object *obj)
>>   		return;
>>   
>>   	if (i915_seqno_passed(ring->get_seqno(ring, true),
>> -			      obj->last_read_seqno))
>> +			      i915_gem_request_get_seqno(obj->last_read_req)))
>>   		i915_gem_object_move_to_inactive(obj);
>>   }
>>   
>> @@ -2669,7 +2677,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
>>   				      struct drm_i915_gem_object,
>>   				      ring_list);
>>   
>> -		if (!i915_seqno_passed(seqno, obj->last_read_seqno))
>> +		if (!i915_seqno_passed(seqno, i915_gem_request_get_seqno(obj->last_read_req)))
>>   			break;
>>   
>>   		i915_gem_object_move_to_inactive(obj);
>> @@ -2779,7 +2787,7 @@ i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
>>   	int ret;
>>   
>>   	if (obj->active) {
>> -		ret = i915_gem_check_olr(obj->ring, obj->last_read_seqno);
>> +		ret = i915_gem_check_olr(obj->ring, i915_gem_request_get_seqno(obj->last_read_req));
>>   		if (ret)
>>   			return ret;
>>   
>> @@ -2838,13 +2846,14 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
>>   		goto out;
>>   
>>   	if (obj->active) {
>> -		seqno = obj->last_read_seqno;
>> +		if (!obj->last_read_req)
>> +			goto out;
>> +
>> +		seqno = i915_gem_request_get_seqno(obj->last_read_req);
>> +		BUG_ON(seqno == 0);
>>   		ring = obj->ring;
>>   	}
>>   
>> -	if (seqno == 0)
>> -		 goto out;
>> -
>>   	/* Do this after OLR check to make sure we make forward progress polling
>>   	 * on this IOCTL with a timeout <=0 (like busy ioctl)
>>   	 */
>> @@ -2894,7 +2903,7 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
>>   
>>   	idx = intel_ring_sync_index(from, to);
>>   
>> -	seqno = obj->last_read_seqno;
>> +	seqno = i915_gem_request_get_seqno(obj->last_read_req);
>>   	/* Optimization: Avoid semaphore sync when we are sure we already
>>   	 * waited for an object with higher seqno */
>>   	if (seqno <= from->semaphore.sync_seqno[idx]) /* <--- broken?! needs to use i915_seqno_passed()??? */
>> @@ -2907,11 +2916,12 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
>>   	trace_i915_gem_ring_sync_to(from, to, seqno);
>>   	ret = to->semaphore.sync_to(to, from, seqno);
>>   	if (!ret)
>> -		/* We use last_read_seqno because sync_to()
>> +		/* We use last_read_req because sync_to()
>>   		 * might have just caused seqno wrap under
>>   		 * the radar.
>>   		 */
>> -		from->semaphore.sync_seqno[idx] = obj->last_read_seqno;
>> +		from->semaphore.sync_seqno[idx] =
>> +				i915_gem_request_get_seqno(obj->last_read_req);
>>   
>>   	return ret;
>>   }
>> @@ -3224,12 +3234,12 @@ static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
>>   static int
>>   i915_gem_object_wait_fence(struct drm_i915_gem_object *obj)
>>   {
>> -	if (obj->last_fenced_seqno) {
>> -		int ret = i915_wait_seqno(obj->ring, obj->last_fenced_seqno);
>> +	if (obj->last_fenced_req) {
>> +		int ret = i915_wait_seqno(obj->ring, i915_gem_request_get_seqno(obj->last_fenced_req));
>>   		if (ret)
>>   			return ret;
>>   
>> -		obj->last_fenced_seqno = 0;
>> +		obj->last_fenced_req = NULL;
>>   	}
>>   
>>   	return 0;
>> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
>> index 1a0611b..4250211 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
>> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
>> @@ -946,7 +946,7 @@ void
>>   i915_gem_execbuffer_move_to_active(struct list_head *vmas,
>>   				   struct intel_engine_cs *ring)
>>   {
>> -	u32 seqno = intel_ring_get_seqno(ring);
>> +	struct drm_i915_gem_request *req = intel_ring_get_request(ring);
>>   	struct i915_vma *vma;
>>   
>>   	list_for_each_entry(vma, vmas, exec_list) {
>> @@ -963,7 +963,7 @@ i915_gem_execbuffer_move_to_active(struct list_head *vmas,
>>   		i915_vma_move_to_active(vma, ring);
>>   		if (obj->base.write_domain) {
>>   			obj->dirty = 1;
>> -			obj->last_write_seqno = seqno;
>> +			obj->last_write_req = req;
>>   
>>   			intel_fb_obj_invalidate(obj, ring);
>>   
>> @@ -971,7 +971,7 @@ i915_gem_execbuffer_move_to_active(struct list_head *vmas,
>>   			obj->base.write_domain &= ~I915_GEM_GPU_DOMAINS;
>>   		}
>>   		if (entry->flags & EXEC_OBJECT_NEEDS_FENCE) {
>> -			obj->last_fenced_seqno = seqno;
>> +			obj->last_fenced_req = req;
>>   			if (entry->flags & __EXEC_OBJECT_HAS_FENCE) {
>>   				struct drm_i915_private *dev_priv = to_i915(ring->dev);
>>   				list_move_tail(&dev_priv->fence_regs[obj->fence_reg].lru_list,
>> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
>> index d5c14af..8a220c0 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_gtt.h
>> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
>> @@ -178,7 +178,7 @@ struct i915_address_space {
>>   	 * List of objects currently involved in rendering.
>>   	 *
>>   	 * Includes buffers having the contents of their GPU caches
>> -	 * flushed, not necessarily primitives.  last_rendering_seqno
>> +	 * flushed, not necessarily primitives.  last_rendering_req
>>   	 * represents when the rendering involved will be completed.
>>   	 *
>>   	 * A reference is held on the buffer while on this list.
>> @@ -189,7 +189,7 @@ struct i915_address_space {
>>   	 * LRU list of objects which are not in the ringbuffer and
>>   	 * are ready to unbind, but are still in the GTT.
>>   	 *
>> -	 * last_rendering_seqno is 0 while an object is in this list.
>> +	 * last_rendering_req is NULL while an object is in this list.
>>   	 *
>>   	 * A reference is not held on the buffer while on this list,
>>   	 * as merely being GTT-bound shouldn't prevent its being
>> diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
>> index 2cefb59..fa5fc8c 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_tiling.c
>> +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
>> @@ -383,7 +383,7 @@ i915_gem_set_tiling(struct drm_device *dev, void *data,
>>   
>>   		if (ret == 0) {
>>   			obj->fence_dirty =
>> -				obj->last_fenced_seqno ||
>> +				obj->last_fenced_req ||
>>   				obj->fence_reg != I915_FENCE_REG_NONE;
>>   
>>   			obj->tiling_mode = args->tiling_mode;
>> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
>> index 2c87a79..1b58390 100644
>> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
>> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
>> @@ -666,8 +666,8 @@ static void capture_bo(struct drm_i915_error_buffer *err,
>>   
>>   	err->size = obj->base.size;
>>   	err->name = obj->base.name;
>> -	err->rseqno = obj->last_read_seqno;
>> -	err->wseqno = obj->last_write_seqno;
>> +	err->rseqno = i915_gem_request_get_seqno(obj->last_read_req);
>> +	err->wseqno = i915_gem_request_get_seqno(obj->last_write_req);
>>   	err->gtt_offset = vma->node.start;
>>   	err->read_domains = obj->base.read_domains;
>>   	err->write_domain = obj->base.write_domain;
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index b78f00a..5aae3d1e 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -9766,16 +9766,16 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
>>   
>>   	lockdep_assert_held(&obj->base.dev->struct_mutex);
>>   
>> -	if (!obj->last_write_seqno)
>> +	if (!obj->last_write_req)
>>   		return 0;
>>   
>>   	ring = obj->ring;
>>   
>>   	if (i915_seqno_passed(ring->get_seqno(ring, true),
>> -			      obj->last_write_seqno))
>> +			      i915_gem_request_get_seqno(obj->last_write_req)))
>>   		return 0;
>>   
>> -	ret = i915_gem_check_olr(ring, obj->last_write_seqno);
>> +	ret = i915_gem_check_olr(ring, i915_gem_request_get_seqno(obj->last_write_req));
>>   	if (ret)
>>   		return ret;
>>   
>> @@ -9838,7 +9838,7 @@ static int intel_queue_mmio_flip(struct drm_device *dev,
>>   	}
>>   
>>   	spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
>> -	intel_crtc->mmio_flip.seqno = obj->last_write_seqno;
>> +	intel_crtc->mmio_flip.seqno = i915_gem_request_get_seqno(obj->last_write_req);
>>   	intel_crtc->mmio_flip.ring_id = obj->ring->id;
>>   	spin_unlock_irqrestore(&dev_priv->mmio_flip_lock, irq_flags);
>>   
>> @@ -10045,7 +10045,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>>   		if (ret)
>>   			goto cleanup_unpin;
>>   
>> -		work->flip_queued_seqno = obj->last_write_seqno;
>> +		work->flip_queued_seqno = i915_gem_request_get_seqno(obj->last_write_req);
>>   		work->flip_queued_ring = obj->ring;
>>   	} else {
>>   		ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, ring,
>> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
>> index cc1b62f..d98b964 100644
>> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
>> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
>> @@ -249,7 +249,7 @@ struct  intel_engine_cs {
>>   	 * ringbuffer.
>>   	 *
>>   	 * Includes buffers having the contents of their GPU caches
>> -	 * flushed, not necessarily primitives.  last_rendering_seqno
>> +	 * flushed, not necessarily primitives.  last_rendering_req
>>   	 * represents when the rendering involved will be completed.
>>   	 *
>>   	 * A reference is held on the buffer while on this list.
>> -- 
>> 1.7.9.5
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [RFC 09/21] drm/i915: Make 'i915_gem_check_olr' actually check by request not seqno

[John Harrison]

On 19/10/2014 13:55, Daniel Vetter wrote:
> On Mon, Oct 06, 2014 at 03:15:13PM +0100, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
> To thin commit message.
>
> Also I wonder whethere we should track the olr state more explicitly in
> the request structure instead of jumping through all these hoops. And
> explicit olr state for a request might also help to clarify control flow
> and checks in a bunch of places.

What would be nicer would be to get rid of the OLR completely. If code 
wants to write to the ring then it should request a request structure at 
the start, pass that request in to all the ring writing code and submit 
the same request structure at the end. The whole idea of some random 
request floating around in the ether scooping up any ring accesses that 
happen to occur with no idea about ownership, sequence, etc. just seems 
highly dodgy. Indeed it definitely causes issues with the scheduler with 
things like page flips being mixed up in completely unrelated batch 
buffer submissions! I believe that is one of the things Chris did in his 
re-write the universe patch.


>> For: VIZ-4377
>> Signed-off-by: John.C.Harrison@Intel.com
>> ---
>>   drivers/gpu/drm/i915/i915_drv.h      |   17 ++++++++++++++++-
>>   drivers/gpu/drm/i915/i915_gem.c      |   25 ++++++++++---------------
>>   drivers/gpu/drm/i915/intel_display.c |    2 +-
>>   3 files changed, 27 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 1401266..9504206 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -2483,7 +2483,7 @@ bool i915_gem_retire_requests(struct drm_device *dev);
>>   void i915_gem_retire_requests_ring(struct intel_engine_cs *ring);
>>   int __must_check i915_gem_check_wedge(struct i915_gpu_error *error,
>>   				      bool interruptible);
>> -int __must_check i915_gem_check_olr(struct intel_engine_cs *ring, u32 seqno);
>> +int __must_check i915_gem_check_olr(struct drm_i915_gem_request *req);
>>   
>>   static inline bool i915_reset_in_progress(struct i915_gpu_error *error)
>>   {
>> @@ -3020,4 +3020,19 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
>>   	}
>>   }
>>   
>> +/************************* Deprecated *************************/
> There's a gcc flag for functions if you want to mark this as depracated,
> otherwise I'd just go with a "XXX: This temporary function will disappear
> at the end of the patch series" somewhere.
>
>> +static inline int __must_check i915_gem_check_ols(struct intel_engine_cs *ring, u32 seqno)
>> +{
>> +	int ret;
>> +
>> +	BUG_ON(!mutex_is_locked(&ring->dev->struct_mutex));
> WARN_ON instead of BUG_ON for locking checks.
>
>> +
>> +	ret = 0;
>> +	if (seqno == i915_gem_request_get_seqno(ring->outstanding_lazy_request))
>> +		ret = i915_add_request(ring, NULL);
>> +
>> +	return ret;
>> +}
>> +/************************* Deprecated *************************/
>> +
>>   #endif
>> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
>> index 0d0eb26..2c7deca 100644
>> --- a/drivers/gpu/drm/i915/i915_gem.c
>> +++ b/drivers/gpu/drm/i915/i915_gem.c
>> @@ -1097,19 +1097,18 @@ i915_gem_check_wedge(struct i915_gpu_error *error,
>>   }
>>   
>>   /*
>> - * Compare seqno against outstanding lazy request. Emit a request if they are
>> - * equal.
>> + * Compare arbitrary request against outstanding lazy request. Emit on match.
>>    */
>>   int
>> -i915_gem_check_olr(struct intel_engine_cs *ring, u32 seqno)
>> +i915_gem_check_olr(struct drm_i915_gem_request *req)
>>   {
>>   	int ret;
>>   
>> -	BUG_ON(!mutex_is_locked(&ring->dev->struct_mutex));
>> +	BUG_ON(!mutex_is_locked(&req->ring->dev->struct_mutex));
> Same here. Plus please a stern warning in the commit message and cc: to
> whomever who managed to sneak this in (and failed to catch it in review).
>>   
>>   	ret = 0;
>> -	if (seqno == i915_gem_request_get_seqno(ring->outstanding_lazy_request))
>> -		ret = i915_add_request(ring, NULL);
>> +	if (req == req->ring->outstanding_lazy_request)
>> +		ret = i915_add_request(req->ring, NULL);
>>   
>>   	return ret;
>>   }
>> @@ -1271,7 +1270,7 @@ i915_wait_seqno(struct intel_engine_cs *ring, uint32_t seqno)
>>   	if (ret)
>>   		return ret;
>>   
>> -	ret = i915_gem_check_olr(ring, seqno);
>> +	ret = i915_gem_check_ols(ring, seqno);
>>   	if (ret)
>>   		return ret;
>>   
>> @@ -1338,7 +1337,6 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
>>   	struct drm_i915_private *dev_priv = dev->dev_private;
>>   	struct intel_engine_cs *ring = obj->ring;
>>   	unsigned reset_counter;
>> -	u32 seqno;
>>   	int ret;
>>   
>>   	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
>> @@ -1348,21 +1346,18 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
>>   	if (!req)
>>   		return 0;
>>   
>> -	seqno = i915_gem_request_get_seqno(req);
>> -	BUG_ON(seqno == 0);
>> -
>>   	ret = i915_gem_check_wedge(&dev_priv->gpu_error, true);
>>   	if (ret)
>>   		return ret;
>>   
>> -	ret = i915_gem_check_olr(ring, seqno);
>> +	ret = i915_gem_check_olr(req);
>>   	if (ret)
>>   		return ret;
>>   
>>   	reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter);
>>   	i915_gem_request_reference(req);
>>   	mutex_unlock(&dev->struct_mutex);
>> -	ret = __wait_seqno(ring, seqno, reset_counter, true, NULL, file_priv);
>> +	ret = __wait_seqno(ring, i915_gem_request_get_seqno(req), reset_counter, true, NULL, file_priv);
>>   	mutex_lock(&dev->struct_mutex);
>>   	i915_gem_request_unreference(req);
>>   	if (ret)
>> @@ -2786,7 +2781,7 @@ i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
>>   	int ret;
>>   
>>   	if (obj->active) {
>> -		ret = i915_gem_check_olr(obj->ring, i915_gem_request_get_seqno(obj->last_read_req));
>> +		ret = i915_gem_check_olr(obj->last_read_req);
>>   		if (ret)
>>   			return ret;
>>   
>> @@ -2913,7 +2908,7 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
>>   	if (seqno <= from->semaphore.sync_seqno[idx]) /* <--- broken?! needs to use i915_seqno_passed()??? */
>>   		return 0;
>>   
>> -	ret = i915_gem_check_olr(obj->ring, seqno);
>> +	ret = i915_gem_check_olr(obj->last_read_req);
>>   	if (ret)
>>   		return ret;
>>   
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index 6da18c5..2af421e 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -9775,7 +9775,7 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
>>   			      i915_gem_request_get_seqno(obj->last_write_req)))
>>   		return 0;
>>   
>> -	ret = i915_gem_check_olr(ring, i915_gem_request_get_seqno(obj->last_write_req));
>> +	ret = i915_gem_check_olr(obj->last_write_req);
>>   	if (ret)
>>   		return ret;
>>   
>> -- 
>> 1.7.9.5
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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Re: [RFC 16/25] drm/i915: Convert most 'i915_seqno_passed' calls into 'i915_gem_request_completed'

[John Harrison]

On 19/10/2014 15:04, Daniel Vetter wrote:
> On Fri, Oct 10, 2014 at 12:39:49PM +0100, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
>>
>> For: VIZ-4377
>> Signed-off-by: John.C.Harrison@Intel.com
>> ---
>>   drivers/gpu/drm/i915/i915_debugfs.c  |    3 +--
>>   drivers/gpu/drm/i915/i915_drv.h      |   18 ++++++++++++++++++
>>   drivers/gpu/drm/i915/i915_gem.c      |   12 ++++--------
>>   drivers/gpu/drm/i915/intel_display.c |   11 +++--------
>>   4 files changed, 26 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
>> index 52ddd19..e764af9 100644
>> --- a/drivers/gpu/drm/i915/i915_debugfs.c
>> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
>> @@ -550,8 +550,7 @@ static int i915_gem_pageflip_info(struct seq_file *m, void *data)
>>   					   i915_gem_request_get_seqno(work->flip_queued_req),
>>   					   dev_priv->next_seqno,
>>   					   work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
>> -					   i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
>> -							     i915_gem_request_get_seqno(work->flip_queued_req)));
>> +					   i915_gem_request_completed(work->flip_queued_req, true));
>>   			} else
>>   				seq_printf(m, "Flip not associated with any ring\n");
>>   			seq_printf(m, "Flip queued on frame %d, (was ready on frame %d), now %d\n",
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 6fe3be0..650f712 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -1970,6 +1970,12 @@ i915_gem_request_unreference(struct drm_i915_gem_request *req)
>>   	kref_put(&req->ref, i915_gem_request_free);
>>   }
>>   
>> +/*
>> + * NB: i915_gem_request_completed should be here but currently needs the
>> + * definition of i915_seqno_passed() which is below. It will be moved in
>> + * a later patch when the call to i915_seqno_passed() is obsoleted...
>> + */
>> +
>>   struct drm_i915_file_private {
>>   	struct drm_i915_private *dev_priv;
>>   	struct drm_file *file;
>> @@ -3019,4 +3025,16 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
>>   	}
>>   }
>>   
>> +static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
>> +					      bool lazy_coherency)
>> +{
>> +	u32 seqno;
>> +
>> +	BUG_ON(req == NULL);
>> +
>> +	seqno = req->ring->get_seqno(req->ring, lazy_coherency);
>> +
>> +	return i915_seqno_passed(seqno, req->seqno);
>> +}
> Tbh this thing looks a bit big for a static inline. Have you
> double-checked that inlining this doesn't increase binary size? If it
> does then we need performance data justifying the cost. Same probably
> applies to some of the other static inline functions you've added.
> -Daniel

It is a replacement for i915_seqno_passed() which is a static inline so 
it seemed sensible that this should be too. Note that the ultimate aim 
is for this to be a simple 'return req->completed'. At which point it 
should certainly be worthy of inlining.

But no I haven't done any actual analysis of the benefit/cost yet. As 
has been mentioned, this RFC was a quick knock up to get something to 
discuss as soon as possible.

>> +
>>   #endif
>> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
>> index e1a58f1..b602e8c 100644
>> --- a/drivers/gpu/drm/i915/i915_gem.c
>> +++ b/drivers/gpu/drm/i915/i915_gem.c
>> @@ -2253,8 +2253,7 @@ i915_gem_object_retire(struct drm_i915_gem_object *obj)
>>   	if (ring == NULL)
>>   		return;
>>   
>> -	if (i915_seqno_passed(ring->get_seqno(ring, true),
>> -			      i915_gem_request_get_seqno(obj->last_read_req)))
>> +	if (i915_gem_request_completed(obj->last_read_req, true))
>>   		i915_gem_object_move_to_inactive(obj);
>>   }
>>   
>> @@ -2521,12 +2520,9 @@ struct drm_i915_gem_request *
>>   i915_gem_find_active_request(struct intel_engine_cs *ring)
>>   {
>>   	struct drm_i915_gem_request *request;
>> -	u32 completed_seqno;
>> -
>> -	completed_seqno = ring->get_seqno(ring, false);
>>   
>>   	list_for_each_entry(request, &ring->request_list, list) {
>> -		if (i915_seqno_passed(completed_seqno, request->seqno))
>> +		if (i915_gem_request_completed(request, false))
>>   			continue;
>>   
>>   		return request;
>> @@ -2670,7 +2666,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
>>   				      struct drm_i915_gem_object,
>>   				      ring_list);
>>   
>> -		if (!i915_seqno_passed(seqno, i915_gem_request_get_seqno(obj->last_read_req)))
>> +		if (!i915_gem_request_completed(obj->last_read_req, true))
>>   			break;
>>   
>>   		i915_gem_object_move_to_inactive(obj);
>> @@ -2685,7 +2681,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
>>   					   struct drm_i915_gem_request,
>>   					   list);
>>   
>> -		if (!i915_seqno_passed(seqno, request->seqno))
>> +		if (!i915_gem_request_completed(request, true))
>>   			break;
>>   
>>   		trace_i915_gem_request_retire(ring, request->seqno);
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index 26fdd96..9ca8f94 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -9771,8 +9771,7 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
>>   
>>   	ring = obj->ring;
>>   
>> -	if (i915_seqno_passed(ring->get_seqno(ring, true),
>> -			      i915_gem_request_get_seqno(obj->last_write_req)))
>> +	if (i915_gem_request_completed(obj->last_write_req, true))
>>   		return 0;
>>   
>>   	ret = i915_gem_check_olr(obj->last_write_req);
>> @@ -9790,9 +9789,6 @@ void intel_notify_mmio_flip(struct intel_engine_cs *ring)
>>   	struct drm_i915_private *dev_priv = to_i915(ring->dev);
>>   	struct intel_crtc *intel_crtc;
>>   	unsigned long irq_flags;
>> -	u32 seqno;
>> -
>> -	seqno = ring->get_seqno(ring, false);
>>   
>>   	spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
>>   	for_each_intel_crtc(ring->dev, intel_crtc) {
>> @@ -9805,7 +9801,7 @@ void intel_notify_mmio_flip(struct intel_engine_cs *ring)
>>   		if (ring->id != mmio_flip->ring_id)
>>   			continue;
>>   
>> -		if (i915_seqno_passed(seqno, i915_gem_request_get_seqno(mmio_flip->req))) {
>> +		if (i915_gem_request_completed(mmio_flip->req, false)) {
>>   			intel_do_mmio_flip(intel_crtc);
>>   			i915_gem_request_unreference(mmio_flip->req);
>>   			mmio_flip->req = NULL;
>> @@ -9878,8 +9874,7 @@ static bool __intel_pageflip_stall_check(struct drm_device *dev,
>>   
>>   	if (work->flip_ready_vblank == 0) {
>>   		if (work->flip_queued_ring &&
>> -		    !i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
>> -				       i915_gem_request_get_seqno(work->flip_queued_req)))
>> +		    !i915_gem_request_completed(work->flip_queued_req, true))
>>   			return false;
>>   
>>   		work->flip_ready_vblank = drm_vblank_count(dev, intel_crtc->pipe);
>> -- 
>> 1.7.9.5
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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Re: [RFC 20/21] drm/i915: Convert 'ring_idle()' to use requests not seqnos

[John Harrison]

On 19/10/2014 15:09, Daniel Vetter wrote:
> On Mon, Oct 06, 2014 at 03:15:24PM +0100, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
>>
>> For: VIZ-4377
>> Signed-off-by: John.C.Harrison@Intel.com
> We have places that shovel stuff onto the ring without an explicit
> add_request. Or at least we've had, so this needs a full audit, and that
> audit needs to be in the commit message.
> -Daniel
Not sure what you mean. There is no functional change here. The old 
version pulled the seqno out of the last request entry in the list and 
compared that to the hardware seqno value to check for completion. The 
new version gets the same request entry and does the same completion 
test, just in request parlance. If commands are being dumped on the ring 
without an request being added to the request list then the old version 
would still not have been checking for them. It would still only look at 
the last piece of work that actually did call add_request and see if 
that has completed or not.

>> ---
>>   drivers/gpu/drm/i915/i915_irq.c |   12 ++++++------
>>   1 file changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
>> index 4847ed5..c2a7127 100644
>> --- a/drivers/gpu/drm/i915/i915_irq.c
>> +++ b/drivers/gpu/drm/i915/i915_irq.c
>> @@ -3030,18 +3030,18 @@ static void gen8_disable_vblank(struct drm_device *dev, int pipe)
>>   	spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
>>   }
>>   
>> -static u32
>> -ring_last_seqno(struct intel_engine_cs *ring)
>> +static struct drm_i915_gem_request *
>> +ring_last_request(struct intel_engine_cs *ring)
>>   {
>>   	return list_entry(ring->request_list.prev,
>> -			  struct drm_i915_gem_request, list)->seqno;
>> +			  struct drm_i915_gem_request, list);
>>   }
>>   
>>   static bool
>> -ring_idle(struct intel_engine_cs *ring, u32 seqno)
>> +ring_idle(struct intel_engine_cs *ring)
>>   {
>>   	return (list_empty(&ring->request_list) ||
>> -		i915_seqno_passed(seqno, ring_last_seqno(ring)));
>> +		i915_gem_request_completed(ring_last_request(ring), false));
>>   }
>>   
>>   static bool
>> @@ -3261,7 +3261,7 @@ static void i915_hangcheck_elapsed(unsigned long data)
>>   		acthd = intel_ring_get_active_head(ring);
>>   
>>   		if (ring->hangcheck.seqno == seqno) {
>> -			if (ring_idle(ring, seqno)) {
>> +			if (ring_idle(ring)) {
>>   				ring->hangcheck.action = HANGCHECK_IDLE;
>>   
>>   				if (waitqueue_active(&ring->irq_queue)) {
>> -- 
>> 1.7.9.5
>>
>> _______________________________________________
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>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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Re: [RFC 21/21] drm/i915: Remove 'obj->ring'

[John Harrison]

On 19/10/2014 15:12, Daniel Vetter wrote:
> On Mon, Oct 06, 2014 at 03:15:25PM +0100, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
>>
>> For: VIZ-4377
>> Signed-off-by: John.C.Harrison@Intel.com
> I think this should be split up into the different parts:
>
> - s/obj->ring/obj->last_read_req->ring/ for all the cases that just want
>    the current ring.
> - s/obj->ring/obj->last_read_req/ I think in a bunch of places the code
>    would actually be more readable if we'd check for obj->active instead.
> - All the oddball special cases probably deserve their own commit + nice
>    explanation in the commit message about why the change is correct.

Can you explain which is which? As for why the change is correct, it is 
not a functional change. obj->ring was assigned with 
obj->last_read_seqno and cleared with obj->last_read_seqno. Thus 
querying obj->ring is equivalent to querying obj->last_read_req->ring in 
all cases. Given that the ring is now available from obj->lrr, it seemed 
redundant to also have it explicitly saved in obj->ring, hence the patch 
to remove it.

AFAICT, there are two examples in debugfs that should just be querying 
obj->active. The rest are pretty much wanting the currently in use ring 
and/or are about to use last_read_req anyway. It seems more sensible to 
say 'if(obj->lrr) { do_stuff(obj->lrr); }' than 'if(obj->active) { 
do_stuff(obj->lrr); }'. Nothing looks particularly 'oddball' to me!


> Cheers, Daniel
>> ---
>>   drivers/gpu/drm/i915/i915_debugfs.c     |    9 +++++----
>>   drivers/gpu/drm/i915/i915_drv.h         |    2 --
>>   drivers/gpu/drm/i915/i915_gem.c         |   32 +++++++++++++++++++------------
>>   drivers/gpu/drm/i915/i915_gem_context.c |   12 +++++++++++-
>>   drivers/gpu/drm/i915/i915_gpu_error.c   |    3 ++-
>>   drivers/gpu/drm/i915/intel_display.c    |   15 ++++++++-------
>>   6 files changed, 46 insertions(+), 27 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
>> index df53515..b1d989f 100644
>> --- a/drivers/gpu/drm/i915/i915_debugfs.c
>> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
>> @@ -168,8 +168,9 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj)
>>   		*t = '\0';
>>   		seq_printf(m, " (%s mappable)", s);
>>   	}
>> -	if (obj->ring != NULL)
>> -		seq_printf(m, " (%s)", obj->ring->name);
>> +	if (obj->last_read_req != NULL)
>> +		seq_printf(m, " (%s)",
>> +			   i915_gem_request_get_ring(obj->last_read_req)->name);
>>   	if (obj->frontbuffer_bits)
>>   		seq_printf(m, " (frontbuffer: 0x%03x)", obj->frontbuffer_bits);
>>   }
>> @@ -336,7 +337,7 @@ static int per_file_stats(int id, void *ptr, void *data)
>>   			if (ppgtt->file_priv != stats->file_priv)
>>   				continue;
>>   
>> -			if (obj->ring) /* XXX per-vma statistic */
>> +			if (obj->last_read_req) /* XXX per-vma statistic */
>>   				stats->active += obj->base.size;
>>   			else
>>   				stats->inactive += obj->base.size;
>> @@ -346,7 +347,7 @@ static int per_file_stats(int id, void *ptr, void *data)
>>   	} else {
>>   		if (i915_gem_obj_ggtt_bound(obj)) {
>>   			stats->global += obj->base.size;
>> -			if (obj->ring)
>> +			if (obj->last_read_req)
>>   				stats->active += obj->base.size;
>>   			else
>>   				stats->inactive += obj->base.size;
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 0790593..cdbbdeb 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -1859,8 +1859,6 @@ struct drm_i915_gem_object {
>>   	void *dma_buf_vmapping;
>>   	int vmapping_count;
>>   
>> -	struct intel_engine_cs *ring;
>> -
>>   	/** Breadcrumb of last rendering to the buffer. */
>>   	struct drm_i915_gem_request *last_read_req;
>>   	struct drm_i915_gem_request *last_write_req;
>> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
>> index d40dad7..561fb81 100644
>> --- a/drivers/gpu/drm/i915/i915_gem.c
>> +++ b/drivers/gpu/drm/i915/i915_gem.c
>> @@ -2184,14 +2184,18 @@ static void
>>   i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
>>   			       struct intel_engine_cs *ring)
>>   {
>> -	struct drm_i915_gem_request *req = intel_ring_get_request(ring);
>> +	struct drm_i915_gem_request *req;
>> +	struct intel_engine_cs *old_ring;
>>   
>>   	BUG_ON(ring == NULL);
>> -	if (obj->ring != ring && obj->last_write_req) {
>> +
>> +	req = intel_ring_get_request(ring);
>> +	old_ring = i915_gem_request_get_ring(obj->last_read_req);
>> +
>> +	if (old_ring != ring && obj->last_write_req) {
>>   		/* Keep the request relative to the current ring */
>>   		obj->last_write_req = req;
>>   	}
>> -	obj->ring = ring;
>>   
>>   	/* Add a reference if we're newly entering the active list. */
>>   	if (!obj->active) {
>> @@ -2230,7 +2234,6 @@ i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
>>   	intel_fb_obj_flush(obj, true);
>>   
>>   	list_del_init(&obj->ring_list);
>> -	obj->ring = NULL;
>>   
>>   	obj->last_read_req = NULL;
>>   	obj->last_write_req = NULL;
>> @@ -2247,9 +2250,7 @@ i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
>>   static void
>>   i915_gem_object_retire(struct drm_i915_gem_object *obj)
>>   {
>> -	struct intel_engine_cs *ring = obj->ring;
>> -
>> -	if (ring == NULL)
>> +	if (obj->last_read_req == NULL)
>>   		return;
>>   
>>   	if (i915_gem_request_completed(obj->last_read_req, true))
>> @@ -2769,14 +2770,17 @@ i915_gem_idle_work_handler(struct work_struct *work)
>>   static int
>>   i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
>>   {
>> +	struct intel_engine_cs *ring;
>>   	int ret;
>>   
>>   	if (obj->active) {
>> +		ring = i915_gem_request_get_ring(obj->last_read_req);
>> +
>>   		ret = i915_gem_check_olr(obj->last_read_req);
>>   		if (ret)
>>   			return ret;
>>   
>> -		i915_gem_retire_requests_ring(obj->ring);
>> +		i915_gem_retire_requests_ring(ring);
>>   	}
>>   
>>   	return 0;
>> @@ -2876,9 +2880,11 @@ int
>>   i915_gem_object_sync(struct drm_i915_gem_object *obj,
>>   		     struct intel_engine_cs *to)
>>   {
>> -	struct intel_engine_cs *from = obj->ring;
>> +	struct intel_engine_cs *from;
>>   	int ret, idx;
>>   
>> +	from = i915_gem_request_get_ring(obj->last_read_req);
>> +
>>   	if (from == NULL || to == from)
>>   		return 0;
>>   
>> @@ -3889,7 +3895,7 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
>>   	bool was_pin_display;
>>   	int ret;
>>   
>> -	if (pipelined != obj->ring) {
>> +	if (pipelined != i915_gem_request_get_ring(obj->last_read_req)) {
>>   		ret = i915_gem_object_sync(obj, pipelined);
>>   		if (ret)
>>   			return ret;
>> @@ -4303,9 +4309,11 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
>>   	ret = i915_gem_object_flush_active(obj);
>>   
>>   	args->busy = obj->active;
>> -	if (obj->ring) {
>> +	if (obj->last_read_req) {
>> +		struct intel_engine_cs *ring;
>>   		BUILD_BUG_ON(I915_NUM_RINGS > 16);
>> -		args->busy |= intel_ring_flag(obj->ring) << 16;
>> +		ring = i915_gem_request_get_ring(obj->last_read_req);
>> +		args->busy |= intel_ring_flag(ring) << 16;
>>   	}
>>   
>>   	drm_gem_object_unreference(&obj->base);
>> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
>> index a5221d8..8f24831 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_context.c
>> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
>> @@ -613,7 +613,17 @@ static int do_switch(struct intel_engine_cs *ring,
>>   		 * swapped, but there is no way to do that yet.
>>   		 */
>>   		from->legacy_hw_ctx.rcs_state->dirty = 1;
>> -		BUG_ON(from->legacy_hw_ctx.rcs_state->ring != ring);
>> +
>> +		/* BUG_ON(i915_gem_request_get_ring(
>> +			from->legacy_hw_ctx.rcs_state->last_read_req) != ring); */
>> +		/* NB: last_read_req has already been updated to the current
>> +		 * request however, that request has not yet been submitted.
>> +		 * Thus last_read_req->ring is guaranteed to be null!
>> +		 * NB2: Doing the check before the update of last_read_req
>> +		 * (which happens in i915_vma_move_to_active() just above),
>> +		 * also fails because last_read_req is almost always null on
>> +		 * entry!
>> +		 */
>>   
>>   		/* obj is kept alive until the next request by its active ref */
>>   		i915_gem_object_ggtt_unpin(from->legacy_hw_ctx.rcs_state);
>> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
>> index 9545d96..b9ecbd9 100644
>> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
>> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
>> @@ -681,7 +681,8 @@ static void capture_bo(struct drm_i915_error_buffer *err,
>>   	err->dirty = obj->dirty;
>>   	err->purgeable = obj->madv != I915_MADV_WILLNEED;
>>   	err->userptr = obj->userptr.mm != NULL;
>> -	err->ring = obj->ring ? obj->ring->id : -1;
>> +	err->ring = obj->last_read_req ?
>> +			i915_gem_request_get_ring(obj->last_read_req)->id : -1;
>>   	err->cache_level = obj->cache_level;
>>   }
>>   
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index 9ca8f94..8238aac 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -9728,7 +9728,7 @@ static bool use_mmio_flip(struct intel_engine_cs *ring,
>>   	else if (i915.enable_execlists)
>>   		return true;
>>   	else
>> -		return ring != obj->ring;
>> +		return ring != i915_gem_request_get_ring(obj->last_read_req);
>>   }
>>   
>>   static void intel_do_mmio_flip(struct intel_crtc *intel_crtc)
>> @@ -9769,8 +9769,6 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
>>   	if (!obj->last_write_req)
>>   		return 0;
>>   
>> -	ring = obj->ring;
>> -
>>   	if (i915_gem_request_completed(obj->last_write_req, true))
>>   		return 0;
>>   
>> @@ -9778,6 +9776,7 @@ static int intel_postpone_flip(struct drm_i915_gem_object *obj)
>>   	if (ret)
>>   		return ret;
>>   
>> +	ring = i915_gem_request_get_ring(obj->last_write_req);
>>   	if (WARN_ON(!ring->irq_get(ring)))
>>   		return 0;
>>   
>> @@ -9837,14 +9836,15 @@ static int intel_queue_mmio_flip(struct drm_device *dev,
>>   	spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
>>   	intel_crtc->mmio_flip.req = obj->last_write_req;
>>   	i915_gem_request_reference(intel_crtc->mmio_flip.req);
>> -	intel_crtc->mmio_flip.ring_id = obj->ring->id;
>> +	BUG_ON(ring != i915_gem_request_get_ring(intel_crtc->mmio_flip.req));
>> +	intel_crtc->mmio_flip.ring_id = ring->id;
>>   	spin_unlock_irqrestore(&dev_priv->mmio_flip_lock, irq_flags);
>>   
>>   	/*
>>   	 * Double check to catch cases where irq fired before
>>   	 * mmio flip data was ready
>>   	 */
>> -	intel_notify_mmio_flip(obj->ring);
>> +	intel_notify_mmio_flip(ring);
>>   	return 0;
>>   }
>>   
>> @@ -10022,7 +10022,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>>   	} else if (IS_IVYBRIDGE(dev)) {
>>   		ring = &dev_priv->ring[BCS];
>>   	} else if (INTEL_INFO(dev)->gen >= 7) {
>> -		ring = obj->ring;
>> +		ring = i915_gem_request_get_ring(obj->last_read_req);
>>   		if (ring == NULL || ring->id != RCS)
>>   			ring = &dev_priv->ring[BCS];
>>   	} else {
>> @@ -10043,7 +10043,8 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>>   			goto cleanup_unpin;
>>   
>>   		work->flip_queued_req = obj->last_write_req;
>> -		work->flip_queued_ring = obj->ring;
>> +		work->flip_queued_ring =
>> +				i915_gem_request_get_ring(obj->last_write_req);
>>   	} else {
>>   		ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, ring,
>>   						   page_flip_flags);
>> -- 
>> 1.7.9.5
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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Re: [RFC 22/21] drm/i915: Cache request completion status

[John Harrison]

On 19/10/2014 15:14, Daniel Vetter wrote:
> On Tue, Oct 07, 2014 at 05:47:29PM +0100, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
>>
>> For: VIZ-4377
>> Signed-off-by: John.C.Harrison@Intel.com
> Why? If it's just for performance I think we should do this as part of the
> switch to struct fence, which already has this.
For performance and also as part of getting rid of all the 
i915_seqno_passed() calls.

>
>> ---
>>   drivers/gpu/drm/i915/i915_drv.h         |   34 ++++++++++++++++---------------
>>   drivers/gpu/drm/i915/i915_gem.c         |   21 +++++++++++++++++++
>>   drivers/gpu/drm/i915/intel_lrc.c        |    1 +
>>   drivers/gpu/drm/i915/intel_ringbuffer.c |    2 ++
>>   drivers/gpu/drm/i915/intel_ringbuffer.h |    3 +++
>>   5 files changed, 45 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index cdbbdeb..4ab3b23 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -1913,6 +1913,9 @@ void i915_gem_track_fb(struct drm_i915_gem_object *old,
>>   struct drm_i915_gem_request {
>>   	struct kref ref;
>>   
>> +	/** Is this request known to be complete? */
>> +	bool complete;
>> +
>>   	/** On Which ring this request was generated */
>>   	struct intel_engine_cs *ring;
>>   
>> @@ -1943,6 +1946,8 @@ struct drm_i915_gem_request {
>>   };
>>   
>>   void i915_gem_request_free(struct kref *req_ref);
>> +void i915_gem_complete_requests_ring(struct intel_engine_cs *ring,
>> +				     bool lazy_coherency);
>>   
>>   static inline uint32_t
>>   i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
>> @@ -1968,7 +1973,19 @@ i915_gem_request_unreference(struct drm_i915_gem_request *req)
>>   	kref_put(&req->ref, i915_gem_request_free);
>>   }
>>   
>> -/* ??? i915_gem_request_completed should be here ??? */
>> +static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
>> +					      bool lazy_coherency)
>> +{
>> +	if (req->complete)
>> +		return true;
>> +
>> +	if (req->ring == NULL)
>> +		return false;
>> +
>> +	i915_gem_complete_requests_ring(req->ring, lazy_coherency);
>> +
>> +	return req->complete;
>> +}
> Also, this is looking way too big now I think ;-) If you have a full
> non-inline function call in your inline it's always a net loss.
> -Daniel
That depends how you define gain/loss. In terms of performance, it can 
still be a gain because the function call is not always taken. Whereas 
the alternative is at least one function calls and possibly two. Either 
way, as noted already, the final intention is for this to become simply 
'return req->complete' and not have any function calls at all.

>
>>   
>>   struct drm_i915_file_private {
>>   	struct drm_i915_private *dev_priv;
>> @@ -3019,19 +3036,4 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
>>   	}
>>   }
>>   
>> -static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
>> -					      bool lazy_coherency)
>> -{
>> -	u32 seqno;
>> -
>> -	BUG_ON(req == NULL);
>> -
>> -	if (req->ring == NULL)
>> -		return false;
>> -
>> -	seqno = req->ring->get_seqno(req->ring, lazy_coherency);
>> -
>> -	return i915_seqno_passed(seqno, req->seqno);
>> -}
>> -
>>   #endif
>> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
>> index 0f14333..0a9b29e 100644
>> --- a/drivers/gpu/drm/i915/i915_gem.c
>> +++ b/drivers/gpu/drm/i915/i915_gem.c
>> @@ -2641,6 +2641,27 @@ void i915_gem_reset(struct drm_device *dev)
>>   	i915_gem_restore_fences(dev);
>>   }
>>   
>> +void i915_gem_complete_requests_ring(struct intel_engine_cs *ring,
>> +				     bool lazy_coherency)
>> +{
>> +	struct drm_i915_gem_request *req;
>> +	u32 seqno;
>> +
>> +	seqno = ring->get_seqno(ring, lazy_coherency);
>> +	if (seqno == ring->last_read_seqno)
>> +		return;
>> +
>> +	list_for_each_entry(req, &ring->request_list, list) {
>> +		if (req->complete)
>> +			continue;
>> +
>> +		if (i915_seqno_passed(seqno, req->seqno))
>> +			req->complete = true;
>> +	}
>> +
>> +	ring->last_read_seqno = seqno;
>> +}
>> +
>>   /**
>>    * This function clears the request list as sequence numbers are passed.
>>    */
>> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
>> index 744684a..57acd2a 100644
>> --- a/drivers/gpu/drm/i915/intel_lrc.c
>> +++ b/drivers/gpu/drm/i915/intel_lrc.c
>> @@ -808,6 +808,7 @@ static int logical_ring_alloc_seqno(struct intel_engine_cs *ring,
>>   
>>   	kref_init(&request->ref);
>>   	request->ring = NULL;
>> +	request->complete = false;
>>   
>>   	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
>>   	if (ret) {
>> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
>> index 0a3c24a..392dc25 100644
>> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
>> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
>> @@ -2023,6 +2023,7 @@ intel_ring_alloc_seqno(struct intel_engine_cs *ring)
>>   
>>   	kref_init(&request->ref);
>>   	request->ring = NULL;
>> +	request->complete = false;
>>   
>>   	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
>>   	if (ret) {
>> @@ -2115,6 +2116,7 @@ void intel_ring_init_seqno(struct intel_engine_cs *ring, u32 seqno)
>>   			I915_WRITE(RING_SYNC_2(ring->mmio_base), 0);
>>   	}
>>   
>> +	ring->last_read_seqno = 0;
>>   	ring->set_seqno(ring, seqno);
>>   	ring->hangcheck.seqno = seqno;
>>   }
>> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
>> index 64a4346..40394d3 100644
>> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
>> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
>> @@ -269,6 +269,9 @@ struct  intel_engine_cs {
>>   	bool gpu_caches_dirty;
>>   	bool fbc_dirty;
>>   
>> +	/* For optimising request completion events */
>> +	u32 last_read_seqno;
>> +
>>   	wait_queue_head_t irq_queue;
>>   
>>   	struct intel_context *default_context;
>> -- 
>> 1.7.9.5
>>
>> _______________________________________________
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>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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Re: [RFC 24/25] drm/i915: Zero fill the request structure

[John Harrison]

On 19/10/2014 15:15, Daniel Vetter wrote:
> On Fri, Oct 10, 2014 at 12:41:12PM +0100, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
>>
>> For: VIZ-4377
>> Signed-off-by: John.C.Harrison@Intel.com
> I think this should be squashed (well, split first) into the relevant
> earlier patches. Generally I much prefer kzalloc, and we use that almost
> everywhere.
>
> Or does this silently fix some issue and doesn't tell?
> -Daniel
No, I just left it separate so as to change as little as possible in 
each individual patch. The original code did a kmalloc() of the request. 
That predates my changes. So if I did a km -> kz change in the middle of 
some other work I was assuming you would complain at me doing too much 
in a single patch. Whereas, the 'complete' field is the first time a 
zero fill becomes significant so it made sense (to me) to leave the 
switch to kz until here.


>> ---
>>   drivers/gpu/drm/i915/intel_lrc.c        |    3 +--
>>   drivers/gpu/drm/i915/intel_ringbuffer.c |    3 +--
>>   2 files changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
>> index 97e6b92..5a75eb5 100644
>> --- a/drivers/gpu/drm/i915/intel_lrc.c
>> +++ b/drivers/gpu/drm/i915/intel_lrc.c
>> @@ -802,13 +802,12 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring,
>>   	if (ring->outstanding_lazy_request)
>>   		return 0;
>>   
>> -	request = kmalloc(sizeof(*request), GFP_KERNEL);
>> +	request = kzalloc(sizeof(*request), GFP_KERNEL);
>>   	if (request == NULL)
>>   		return -ENOMEM;
>>   
>>   	kref_init(&request->ref);
>>   	request->ring = ring;
>> -	request->complete = false;
>>   
>>   	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
>>   	if (ret) {
>> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
>> index df9c7e3..0f2719d 100644
>> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
>> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
>> @@ -2017,13 +2017,12 @@ intel_ring_alloc_request(struct intel_engine_cs *ring)
>>   	if (ring->outstanding_lazy_request)
>>   		return 0;
>>   
>> -	request = kmalloc(sizeof(*request), GFP_KERNEL);
>> +	request = kzalloc(sizeof(*request), GFP_KERNEL);
>>   	if (request == NULL)
>>   		return -ENOMEM;
>>   
>>   	kref_init(&request->ref);
>>   	request->ring = ring;
>> -	request->complete = false;
>>   
>>   	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
>>   	if (ret) {
>> -- 
>> 1.7.9.5
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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Re: [RFC 21/21] drm/i915: Remove 'obj->ring'

[Daniel Vetter]

On Tue, Oct 28, 2014 at 03:09:07PM +0000, John Harrison wrote:
> On 19/10/2014 15:12, Daniel Vetter wrote:
> >On Mon, Oct 06, 2014 at 03:15:25PM +0100, John.C.Harrison@Intel.com wrote:
> >>From: John Harrison <John.C.Harrison@Intel.com>
> >>
> >>For: VIZ-4377
> >>Signed-off-by: John.C.Harrison@Intel.com
> >I think this should be split up into the different parts:
> >
> >- s/obj->ring/obj->last_read_req->ring/ for all the cases that just want
> >   the current ring.
> >- s/obj->ring/obj->last_read_req/ I think in a bunch of places the code
> >   would actually be more readable if we'd check for obj->active instead.
> >- All the oddball special cases probably deserve their own commit + nice
> >   explanation in the commit message about why the change is correct.
> 
> Can you explain which is which? As for why the change is correct, it is not
> a functional change. obj->ring was assigned with obj->last_read_seqno and
> cleared with obj->last_read_seqno. Thus querying obj->ring is equivalent to
> querying obj->last_read_req->ring in all cases. Given that the ring is now
> available from obj->lrr, it seemed redundant to also have it explicitly
> saved in obj->ring, hence the patch to remove it.
> 
> AFAICT, there are two examples in debugfs that should just be querying
> obj->active. The rest are pretty much wanting the currently in use ring
> and/or are about to use last_read_req anyway. It seems more sensible to say
> 'if(obj->lrr) { do_stuff(obj->lrr); }' than 'if(obj->active) {
> do_stuff(obj->lrr); }'. Nothing looks particularly 'oddball' to me!

[snip]

> >>+			if (obj->last_read_req) /* XXX per-vma statistic */
> >>  				stats->active += obj->base.size;

Stuff like this here is what I've meant. Checking for obj->active here is
better, and you might as well ditch the XXX comment too.

You're right that it's all semantically equivalent and your change here is
the less risky since there's no way behaviour can change. But code is
mostly written so that other humans can understand it (when debugging it),
so conveying as much meaning as possible is important. And this looks like
a good opportunity to review all the various places and make sure the code
is sane. We have accumulated a bit of cruft from the per-vma rework and
there's more cruft on the horizon with potentially multiple read fences,
so I think this is worth it.
-Daniel
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Re: [RFC 20/21] drm/i915: Convert 'ring_idle()' to use requests not seqnos

[Daniel Vetter]

On Tue, Oct 28, 2014 at 02:03:14PM +0000, John Harrison wrote:
> On 19/10/2014 15:09, Daniel Vetter wrote:
> >We have places that shovel stuff onto the ring without an explicit
> >add_request. Or at least we've had, so this needs a full audit, and that
> >audit needs to be in the commit message.
> Not sure what you mean. There is no functional change here. The old version
> pulled the seqno out of the last request entry in the list and compared that
> to the hardware seqno value to check for completion. The new version gets
> the same request entry and does the same completion test, just in request
> parlance. If commands are being dumped on the ring without an request being
> added to the request list then the old version would still not have been
> checking for them. It would still only look at the last piece of work that
> actually did call add_request and see if that has completed or not.

Oh, I've pretty badly mixed stuff up ;-)

The issue I'm seeing here though is acessing the request list, from irq
context, without any locks. Pre-existing, but still deserves a FIXME
comment.

Wrt the change itself I'm not sure it's that useful, this is fairly
low-level code.
-Daniel
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Re: [RFC 09/21] drm/i915: Make 'i915_gem_check_olr' actually check by request not seqno

[Daniel Vetter]

On Tue, Oct 28, 2014 at 02:01:52PM +0000, John Harrison wrote:
> On 19/10/2014 13:55, Daniel Vetter wrote:
> >On Mon, Oct 06, 2014 at 03:15:13PM +0100, John.C.Harrison@Intel.com wrote:
> >>From: John Harrison <John.C.Harrison@Intel.com>
> >To thin commit message.
> >
> >Also I wonder whethere we should track the olr state more explicitly in
> >the request structure instead of jumping through all these hoops. And
> >explicit olr state for a request might also help to clarify control flow
> >and checks in a bunch of places.
> 
> What would be nicer would be to get rid of the OLR completely. If code wants
> to write to the ring then it should request a request structure at the
> start, pass that request in to all the ring writing code and submit the same
> request structure at the end. The whole idea of some random request floating
> around in the ether scooping up any ring accesses that happen to occur with
> no idea about ownership, sequence, etc. just seems highly dodgy. Indeed it
> definitely causes issues with the scheduler with things like page flips
> being mixed up in completely unrelated batch buffer submissions! I believe
> that is one of the things Chris did in his re-write the universe patch.

Oh OLR is highly dodgy ;-)

It is unfortunately a bit of work to fix things up, especially without a
rewrite-the-universe patch. Perhaps:
1. Explicitly preallocate the request, still store it at the same place.
2. Pass the explicit request to add_request, add any missing add_requests
call where we currently relied on the olr to scoop up register writes.
3. Shovel the request pointer from the engine to the ring (since that's
where we need it it for execlist), that means we need to allocate the
request for a specific engine. Steps 1&3 might be better if switched,
dunno.
4. Sprinkle asserts over all ring functions to make sure the request is
there already.
5. Throw away olr logic.
6. Optional, refactoring over the next few years: Use requests as the
primary cmd submission object everywhere.

Comments?
-Daniel
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Software Engineer, Intel Corporation
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Re: [RFC 22/21] drm/i915: Cache request completion status

[Daniel Vetter]

On Tue, Oct 28, 2014 at 03:36:29PM +0000, John Harrison wrote:
> On 19/10/2014 15:14, Daniel Vetter wrote:
> >On Tue, Oct 07, 2014 at 05:47:29PM +0100, John.C.Harrison@Intel.com wrote:
> >>From: John Harrison <John.C.Harrison@Intel.com>
> >>
> >>For: VIZ-4377
> >>Signed-off-by: John.C.Harrison@Intel.com
> >Why? If it's just for performance I think we should do this as part of the
> >switch to struct fence, which already has this.
> For performance and also as part of getting rid of all the
> i915_seqno_passed() calls.

The why was more a request for a proper commit message. If you claim
perfomance, then the commit message also needs the relevant data.

> >>---
> >>  drivers/gpu/drm/i915/i915_drv.h         |   34 ++++++++++++++++---------------
> >>  drivers/gpu/drm/i915/i915_gem.c         |   21 +++++++++++++++++++
> >>  drivers/gpu/drm/i915/intel_lrc.c        |    1 +
> >>  drivers/gpu/drm/i915/intel_ringbuffer.c |    2 ++
> >>  drivers/gpu/drm/i915/intel_ringbuffer.h |    3 +++
> >>  5 files changed, 45 insertions(+), 16 deletions(-)
> >>
> >>diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> >>index cdbbdeb..4ab3b23 100644
> >>--- a/drivers/gpu/drm/i915/i915_drv.h
> >>+++ b/drivers/gpu/drm/i915/i915_drv.h
> >>@@ -1913,6 +1913,9 @@ void i915_gem_track_fb(struct drm_i915_gem_object *old,
> >>  struct drm_i915_gem_request {
> >>  	struct kref ref;
> >>+	/** Is this request known to be complete? */
> >>+	bool complete;
> >>+
> >>  	/** On Which ring this request was generated */
> >>  	struct intel_engine_cs *ring;
> >>@@ -1943,6 +1946,8 @@ struct drm_i915_gem_request {
> >>  };
> >>  void i915_gem_request_free(struct kref *req_ref);
> >>+void i915_gem_complete_requests_ring(struct intel_engine_cs *ring,
> >>+				     bool lazy_coherency);
> >>  static inline uint32_t
> >>  i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
> >>@@ -1968,7 +1973,19 @@ i915_gem_request_unreference(struct drm_i915_gem_request *req)
> >>  	kref_put(&req->ref, i915_gem_request_free);
> >>  }
> >>-/* ??? i915_gem_request_completed should be here ??? */
> >>+static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
> >>+					      bool lazy_coherency)
> >>+{
> >>+	if (req->complete)
> >>+		return true;
> >>+
> >>+	if (req->ring == NULL)
> >>+		return false;
> >>+
> >>+	i915_gem_complete_requests_ring(req->ring, lazy_coherency);
> >>+
> >>+	return req->complete;
> >>+}
> >Also, this is looking way too big now I think ;-) If you have a full
> >non-inline function call in your inline it's always a net loss.
> >-Daniel
> That depends how you define gain/loss. In terms of performance, it can still
> be a gain because the function call is not always taken. Whereas the
> alternative is at least one function calls and possibly two. Either way, as
> noted already, the final intention is for this to become simply 'return
> req->complete' and not have any function calls at all.

Thrashing instructions caches is usually what this does, so even when you
microbenchmark a gain it might be a net loss. Rule-of-thumb is static
inline is ok if it results in a net reduction of the binary, not for any
other case.

Unless you supply solid performance data justifying it.

Also, static inlines in random headers are a pain for documentation.
-Daniel
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Re: [RFC 24/25] drm/i915: Zero fill the request structure

[Daniel Vetter]

On Tue, Oct 28, 2014 at 03:55:21PM +0000, John Harrison wrote:
> On 19/10/2014 15:15, Daniel Vetter wrote:
> >On Fri, Oct 10, 2014 at 12:41:12PM +0100, John.C.Harrison@Intel.com wrote:
> >>From: John Harrison <John.C.Harrison@Intel.com>
> >>
> >>For: VIZ-4377
> >>Signed-off-by: John.C.Harrison@Intel.com
> >I think this should be squashed (well, split first) into the relevant
> >earlier patches. Generally I much prefer kzalloc, and we use that almost
> >everywhere.
> >
> >Or does this silently fix some issue and doesn't tell?
> >-Daniel
> No, I just left it separate so as to change as little as possible in each
> individual patch. The original code did a kmalloc() of the request. That
> predates my changes. So if I did a km -> kz change in the middle of some
> other work I was assuming you would complain at me doing too much in a
> single patch. Whereas, the 'complete' field is the first time a zero fill
> becomes significant so it made sense (to me) to leave the switch to kz until
> here.

Makes sense, but this kind of explanation really should be in the commit
message.
-Daniel
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