[PATCH 06/13] drm/i915: Remove the defunct flushing list

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

As we guarantee to emit a flush before emitting the breadcrumb or
the next batchbuffer, there is no further need for the flushing list.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_debugfs.c   |    7 ----
 drivers/gpu/drm/i915/i915_drv.h       |   19 +++--------
 drivers/gpu/drm/i915/i915_gem.c       |   58 +++++----------------------------
 drivers/gpu/drm/i915/i915_gem_evict.c |   20 ------------
 4 files changed, 13 insertions(+), 91 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index a8b7db6..1312b79 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -44,7 +44,6 @@
 
 enum {
 	ACTIVE_LIST,
-	FLUSHING_LIST,
 	INACTIVE_LIST,
 	PINNED_LIST,
 };
@@ -178,10 +177,6 @@ static int i915_gem_object_list_info(struct seq_file *m, void *data)
 		seq_printf(m, "Inactive:\n");
 		head = &dev_priv->mm.inactive_list;
 		break;
-	case FLUSHING_LIST:
-		seq_printf(m, "Flushing:\n");
-		head = &dev_priv->mm.flushing_list;
-		break;
 	default:
 		mutex_unlock(&dev->struct_mutex);
 		return -EINVAL;
@@ -239,7 +234,6 @@ static int i915_gem_object_info(struct seq_file *m, void* data)
 
 	size = count = mappable_size = mappable_count = 0;
 	count_objects(&dev_priv->mm.active_list, mm_list);
-	count_objects(&dev_priv->mm.flushing_list, mm_list);
 	seq_printf(m, "  %u [%u] active objects, %zu [%zu] bytes\n",
 		   count, mappable_count, size, mappable_size);
 
@@ -2007,7 +2001,6 @@ static struct drm_info_list i915_debugfs_list[] = {
 	{"i915_gem_gtt", i915_gem_gtt_info, 0},
 	{"i915_gem_pinned", i915_gem_gtt_info, 0, (void *) PINNED_LIST},
 	{"i915_gem_active", i915_gem_object_list_info, 0, (void *) ACTIVE_LIST},
-	{"i915_gem_flushing", i915_gem_object_list_info, 0, (void *) FLUSHING_LIST},
 	{"i915_gem_inactive", i915_gem_object_list_info, 0, (void *) INACTIVE_LIST},
 	{"i915_gem_pageflip", i915_gem_pageflip_info, 0},
 	{"i915_gem_request", i915_gem_request_info, 0},
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b398b72..203562b 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -696,17 +696,6 @@ typedef struct drm_i915_private {
 		struct list_head active_list;
 
 		/**
-		 * List of objects which are not in the ringbuffer but which
-		 * still have a write_domain which needs to be flushed before
-		 * unbinding.
-		 *
-		 * last_rendering_seqno is 0 while an object is in this list.
-		 *
-		 * A reference is held on the buffer while on this list.
-		 */
-		struct list_head flushing_list;
-
-		/**
 		 * LRU list of objects which are not in the ringbuffer and
 		 * are ready to unbind, but are still in the GTT.
 		 *
@@ -873,7 +862,7 @@ struct drm_i915_gem_object {
 	struct drm_mm_node *gtt_space;
 	struct list_head gtt_list;
 
-	/** This object's place on the active/flushing/inactive lists */
+	/** This object's place on the active/inactive lists */
 	struct list_head ring_list;
 	struct list_head mm_list;
 	/** This object's place on GPU write list */
@@ -882,9 +871,9 @@ struct drm_i915_gem_object {
 	struct list_head exec_list;
 
 	/**
-	 * This is set if the object is on the active or flushing lists
-	 * (has pending rendering), and is not set if it's on inactive (ready
-	 * to be unbound).
+	 * This is set if the object is on the active lists (has pending
+	 * rendering and so a non-zero seqno), and is not set if it i s on
+	 * inactive (ready to be unbound) list.
 	 */
 	unsigned int active:1;
 
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 49b8864..ee20fdb 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1458,27 +1458,6 @@ i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
 }
 
 static void
-i915_gem_object_move_off_active(struct drm_i915_gem_object *obj)
-{
-	list_del_init(&obj->ring_list);
-	obj->last_read_seqno = 0;
-	obj->last_write_seqno = 0;
-	obj->last_fenced_seqno = 0;
-}
-
-static void
-i915_gem_object_move_to_flushing(struct drm_i915_gem_object *obj)
-{
-	struct drm_device *dev = obj->base.dev;
-	drm_i915_private_t *dev_priv = dev->dev_private;
-
-	BUG_ON(!obj->active);
-	list_move_tail(&obj->mm_list, &dev_priv->mm.flushing_list);
-
-	i915_gem_object_move_off_active(obj);
-}
-
-static void
 i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
 {
 	struct drm_device *dev = obj->base.dev;
@@ -1488,9 +1467,15 @@ i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
 
 	BUG_ON(!list_empty(&obj->gpu_write_list));
 	BUG_ON(!obj->active);
+
+	list_del_init(&obj->ring_list);
 	obj->ring = NULL;
 
-	i915_gem_object_move_off_active(obj);
+	obj->last_read_seqno = 0;
+	obj->last_write_seqno = 0;
+	obj->base.write_domain &= ~I915_GEM_GPU_DOMAINS;
+
+	obj->last_fenced_seqno = 0;
 	obj->fenced_gpu_access = false;
 
 	obj->active = 0;
@@ -1693,7 +1678,6 @@ static void i915_gem_reset_ring_lists(struct drm_i915_private *dev_priv,
 				       struct drm_i915_gem_object,
 				       ring_list);
 
-		obj->base.write_domain = 0;
 		list_del_init(&obj->gpu_write_list);
 		i915_gem_object_move_to_inactive(obj);
 	}
@@ -1730,20 +1714,6 @@ void i915_gem_reset(struct drm_device *dev)
 	for_each_ring(ring, dev_priv, i)
 		i915_gem_reset_ring_lists(dev_priv, ring);
 
-	/* Remove anything from the flushing lists. The GPU cache is likely
-	 * to be lost on reset along with the data, so simply move the
-	 * lost bo to the inactive list.
-	 */
-	while (!list_empty(&dev_priv->mm.flushing_list)) {
-		obj = list_first_entry(&dev_priv->mm.flushing_list,
-				      struct drm_i915_gem_object,
-				      mm_list);
-
-		obj->base.write_domain = 0;
-		list_del_init(&obj->gpu_write_list);
-		i915_gem_object_move_to_inactive(obj);
-	}
-
 	/* Move everything out of the GPU domains to ensure we do any
 	 * necessary invalidation upon reuse.
 	 */
@@ -1814,10 +1784,7 @@ i915_gem_retire_requests_ring(struct intel_ring_buffer *ring)
 		if (!i915_seqno_passed(seqno, obj->last_read_seqno))
 			break;
 
-		if (obj->base.write_domain != 0)
-			i915_gem_object_move_to_flushing(obj);
-		else
-			i915_gem_object_move_to_inactive(obj);
+		i915_gem_object_move_to_inactive(obj);
 	}
 
 	if (unlikely(ring->trace_irq_seqno &&
@@ -3891,7 +3858,6 @@ i915_gem_entervt_ioctl(struct drm_device *dev, void *data,
 	}
 
 	BUG_ON(!list_empty(&dev_priv->mm.active_list));
-	BUG_ON(!list_empty(&dev_priv->mm.flushing_list));
 	BUG_ON(!list_empty(&dev_priv->mm.inactive_list));
 	mutex_unlock(&dev->struct_mutex);
 
@@ -3949,7 +3915,6 @@ i915_gem_load(struct drm_device *dev)
 	drm_i915_private_t *dev_priv = dev->dev_private;
 
 	INIT_LIST_HEAD(&dev_priv->mm.active_list);
-	INIT_LIST_HEAD(&dev_priv->mm.flushing_list);
 	INIT_LIST_HEAD(&dev_priv->mm.inactive_list);
 	INIT_LIST_HEAD(&dev_priv->mm.fence_list);
 	INIT_LIST_HEAD(&dev_priv->mm.gtt_list);
@@ -4200,12 +4165,7 @@ static int
 i915_gpu_is_active(struct drm_device *dev)
 {
 	drm_i915_private_t *dev_priv = dev->dev_private;
-	int lists_empty;
-
-	lists_empty = list_empty(&dev_priv->mm.flushing_list) &&
-		      list_empty(&dev_priv->mm.active_list);
-
-	return !lists_empty;
+	return !list_empty(&dev_priv->mm.active_list);
 }
 
 static int
diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
index ae7c24e..f61af59 100644
--- a/drivers/gpu/drm/i915/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
@@ -92,23 +92,6 @@ i915_gem_evict_something(struct drm_device *dev, int min_size,
 
 	/* Now merge in the soon-to-be-expired objects... */
 	list_for_each_entry(obj, &dev_priv->mm.active_list, mm_list) {
-		/* Does the object require an outstanding flush? */
-		if (obj->base.write_domain)
-			continue;
-
-		if (mark_free(obj, &unwind_list))
-			goto found;
-	}
-
-	/* Finally add anything with a pending flush (in order of retirement) */
-	list_for_each_entry(obj, &dev_priv->mm.flushing_list, mm_list) {
-		if (mark_free(obj, &unwind_list))
-			goto found;
-	}
-	list_for_each_entry(obj, &dev_priv->mm.active_list, mm_list) {
-		if (!obj->base.write_domain)
-			continue;
-
 		if (mark_free(obj, &unwind_list))
 			goto found;
 	}
@@ -171,7 +154,6 @@ i915_gem_evict_everything(struct drm_device *dev, bool purgeable_only)
 	int ret;
 
 	lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
-		       list_empty(&dev_priv->mm.flushing_list) &&
 		       list_empty(&dev_priv->mm.active_list));
 	if (lists_empty)
 		return -ENOSPC;
@@ -188,8 +170,6 @@ i915_gem_evict_everything(struct drm_device *dev, bool purgeable_only)
 
 	i915_gem_retire_requests(dev);
 
-	BUG_ON(!list_empty(&dev_priv->mm.flushing_list));
-
 	/* Having flushed everything, unbind() should never raise an error */
 	list_for_each_entry_safe(obj, next,
 				 &dev_priv->mm.inactive_list, mm_list) {
-- 
1.7.10.4