[PATCH 18/21] drm/i915: Split out i915_gem_object_move_to_ring() from execbuffer

[Chris Wilson <chris@chris-wilson.co.uk>]

As we can make use of the ability to insert semaphores to serialise
accessing buffers between ring elsewhere, separate out the function from
the execbuffer code and make it generic.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_drv.h            |    5 +++
 drivers/gpu/drm/i915/i915_gem.c            |   40 ++++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |   43 +---------------------------
 3 files changed, 46 insertions(+), 42 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 76e111c..30fbf3b 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -940,6 +940,7 @@ enum intel_chip_family {
 #define HAS_BSD(dev)            (INTEL_INFO(dev)->has_bsd_ring)
 #define HAS_BLT(dev)            (INTEL_INFO(dev)->has_blt_ring)
 #define I915_NEED_GFX_HWS(dev)	(INTEL_INFO(dev)->need_gfx_hws)
+#define HAS_GPU_SEMAPHORES(dev) (INTEL_INFO(dev)->gen >= 6 && i915_semaphores)
 
 #define HAS_OVERLAY(dev)		(INTEL_INFO(dev)->has_overlay)
 #define OVERLAY_NEEDS_PHYSICAL(dev)	(INTEL_INFO(dev)->overlay_needs_physical)
@@ -1198,6 +1199,10 @@ void i915_gem_detach_phys_object(struct drm_device *dev,
 void i915_gem_free_all_phys_object(struct drm_device *dev);
 void i915_gem_release(struct drm_device *dev, struct drm_file *file);
 
+int __must_check
+i915_gem_object_move_to_ring(struct drm_i915_gem_object *obj,
+			     struct intel_ring_buffer *to);
+
 uint32_t
 i915_gem_get_unfenced_gtt_alignment(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 58e77d6..801496a 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1658,6 +1658,46 @@ i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj)
 	obj->pages = NULL;
 }
 
+int
+i915_gem_object_move_to_ring(struct drm_i915_gem_object *obj,
+			     struct intel_ring_buffer *to)
+{
+	struct intel_ring_buffer *from = obj->ring;
+	u32 seqno;
+	int ret, idx;
+
+	if (from == NULL || to == from)
+		return 0;
+
+	if (to == NULL || !HAS_GPU_SEMAPHORES(obj->base.dev))
+		return i915_gem_object_wait_rendering(obj);
+
+	idx = intel_ring_sync_index(from, to);
+
+	seqno = obj->last_rendering_seqno;
+	if (seqno <= from->sync_seqno[idx])
+		return 0;
+
+	if (seqno == from->outstanding_lazy_request) {
+		struct drm_i915_gem_request *request;
+
+		request = kzalloc(sizeof(*request), GFP_KERNEL);
+		if (request == NULL)
+			return -ENOMEM;
+
+		ret = i915_add_request(from, NULL, request);
+		if (ret) {
+			kfree(request);
+			return ret;
+		}
+
+		seqno = request->seqno;
+	}
+
+	from->sync_seqno[idx] = seqno;
+	return intel_ring_sync(to, from, seqno - 1);
+}
+
 void
 i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
 			       struct intel_ring_buffer *ring,
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index b6f89f9..316603e 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -756,47 +756,6 @@ i915_gem_execbuffer_flush(struct drm_device *dev,
 }
 
 static int
-i915_gem_execbuffer_sync_rings(struct drm_i915_gem_object *obj,
-			       struct intel_ring_buffer *to)
-{
-	struct intel_ring_buffer *from = obj->ring;
-	u32 seqno;
-	int ret, idx;
-
-	if (from == NULL || to == from)
-		return 0;
-
-	/* XXX gpu semaphores are implicated in various hard hangs on SNB */
-	if (INTEL_INFO(obj->base.dev)->gen < 6 || !i915_semaphores)
-		return i915_gem_object_wait_rendering(obj);
-
-	idx = intel_ring_sync_index(from, to);
-
-	seqno = obj->last_rendering_seqno;
-	if (seqno <= from->sync_seqno[idx])
-		return 0;
-
-	if (seqno == from->outstanding_lazy_request) {
-		struct drm_i915_gem_request *request;
-
-		request = kzalloc(sizeof(*request), GFP_KERNEL);
-		if (request == NULL)
-			return -ENOMEM;
-
-		ret = i915_add_request(from, NULL, request);
-		if (ret) {
-			kfree(request);
-			return ret;
-		}
-
-		seqno = request->seqno;
-	}
-
-	from->sync_seqno[idx] = seqno;
-	return intel_ring_sync(to, from, seqno - 1);
-}
-
-static int
 i915_gem_execbuffer_wait_for_flips(struct intel_ring_buffer *ring, u32 flips)
 {
 	u32 plane, flip_mask;
@@ -857,7 +816,7 @@ i915_gem_execbuffer_move_to_gpu(struct intel_ring_buffer *ring,
 	}
 
 	list_for_each_entry(obj, objects, exec_list) {
-		ret = i915_gem_execbuffer_sync_rings(obj, ring);
+		ret = i915_gem_object_move_to_ring(obj, ring);
 		if (ret)
 			return ret;
 	}
-- 
1.7.4.1