drm/i915: Remove the per-ring write list

This is now handled by a global flag to ensure we emit a flush before
the next serialisation point (if we failed to queue one previously).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -865,8 +865,6 @@ struct drm_i915_gem_object {
 	/** 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 */
-	struct list_head gpu_write_list;
 	/** This object's place in the batchbuffer or on the eviction list */
 	struct list_head exec_list;
 

drivers/gpu/drm/i915/i915_gem.c

@@ -1465,7 +1465,6 @@ i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
 
 	list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
 
-	BUG_ON(!list_empty(&obj->gpu_write_list));
 	BUG_ON(obj->base.write_domain & ~I915_GEM_GPU_DOMAINS);
 	BUG_ON(!obj->active);
 
@@ -1511,30 +1510,6 @@ i915_gem_object_is_purgeable(struct drm_i915_gem_object *obj)
 	return obj->madv == I915_MADV_DONTNEED;
 }
 
-static void
-i915_gem_process_flushing_list(struct intel_ring_buffer *ring,
-			       uint32_t flush_domains)
-{
-	struct drm_i915_gem_object *obj, *next;
-
-	list_for_each_entry_safe(obj, next,
-				 &ring->gpu_write_list,
-				 gpu_write_list) {
-		if (obj->base.write_domain & flush_domains) {
-			uint32_t old_write_domain = obj->base.write_domain;
-
-			obj->base.write_domain = 0;
-			list_del_init(&obj->gpu_write_list);
-			i915_gem_object_move_to_active(obj, ring,
-						       i915_gem_next_request_seqno(ring));
-
-			trace_i915_gem_object_change_domain(obj,
-							    obj->base.read_domains,
-							    old_write_domain);
-		}
-	}
-}
-
 static u32
 i915_gem_get_seqno(struct drm_device *dev)
 {
@@ -1637,8 +1612,6 @@ i915_add_request(struct intel_ring_buffer *ring,
 					   &dev_priv->mm.retire_work, HZ);
 	}
 
-	WARN_ON(!list_empty(&ring->gpu_write_list));
-
 	return 0;
 }
 
@@ -1680,7 +1653,6 @@ static void i915_gem_reset_ring_lists(struct drm_i915_private *dev_priv,
 				       struct drm_i915_gem_object,
 				       ring_list);
 
-		list_del_init(&obj->gpu_write_list);
 		i915_gem_object_move_to_inactive(obj);
 	}
 }
@@ -2011,11 +1983,6 @@ i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj,
 	u32 seqno;
 	int ret;
 
-	/* This function only exists to support waiting for existing rendering,
-	 * not for emitting required flushes.
-	 */
-	BUG_ON((obj->base.write_domain & I915_GEM_GPU_DOMAINS) != 0);
-
 	/* If there is rendering queued on the buffer being evicted, wait for
 	 * it.
 	 */
@@ -2308,26 +2275,14 @@ i915_gem_flush_ring(struct intel_ring_buffer *ring,
 	if (ret)
 		return ret;
 
-	if (flush_domains & I915_GEM_GPU_DOMAINS)
-		i915_gem_process_flushing_list(ring, flush_domains);
-
 	return 0;
 }
 
 static int i915_ring_idle(struct intel_ring_buffer *ring)
 {
-	int ret;
-
-	if (list_empty(&ring->gpu_write_list) && list_empty(&ring->active_list))
+	if (list_empty(&ring->active_list))
 		return 0;
 
-	if (!list_empty(&ring->gpu_write_list)) {
-		ret = i915_gem_flush_ring(ring,
-				    I915_GEM_GPU_DOMAINS, I915_GEM_GPU_DOMAINS);
-		if (ret)
-			return ret;
-	}
-
 	return i915_wait_seqno(ring, i915_gem_next_request_seqno(ring));
 }
 
@@ -2343,10 +2298,6 @@ int i915_gpu_idle(struct drm_device *dev)
 		if (ret)
 			return ret;
 
-		/* Is the device fubar? */
-		if (WARN_ON(!list_empty(&ring->gpu_write_list)))
-			return -EBUSY;
-
 		ret = i915_switch_context(ring, NULL, DEFAULT_CONTEXT_ID);
 		if (ret)
 			return ret;
@@ -3491,7 +3442,6 @@ struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
 	INIT_LIST_HEAD(&obj->gtt_list);
 	INIT_LIST_HEAD(&obj->ring_list);
 	INIT_LIST_HEAD(&obj->exec_list);
-	INIT_LIST_HEAD(&obj->gpu_write_list);
 	obj->madv = I915_MADV_WILLNEED;
 	/* Avoid an unnecessary call to unbind on the first bind. */
 	obj->map_and_fenceable = true;
@@ -3912,7 +3862,6 @@ init_ring_lists(struct intel_ring_buffer *ring)
 {
 	INIT_LIST_HEAD(&ring->active_list);
 	INIT_LIST_HEAD(&ring->request_list);
-	INIT_LIST_HEAD(&ring->gpu_write_list);
 }
 
 void

drivers/gpu/drm/i915/i915_gem_execbuffer.c

@@ -943,9 +943,8 @@ i915_gem_execbuffer_move_to_active(struct list_head *objects,
 	struct drm_i915_gem_object *obj;
 
 	list_for_each_entry(obj, objects, exec_list) {
-		  u32 old_read = obj->base.read_domains;
-		  u32 old_write = obj->base.write_domain;
-
+		u32 old_read = obj->base.read_domains;
+		u32 old_write = obj->base.write_domain;
 
 		obj->base.read_domains = obj->base.pending_read_domains;
 		obj->base.write_domain = obj->base.pending_write_domain;
@@ -955,8 +954,6 @@ i915_gem_execbuffer_move_to_active(struct list_head *objects,
 		if (obj->base.write_domain) {
 			obj->dirty = 1;
 			obj->last_write_seqno = seqno;
-			list_move_tail(&obj->gpu_write_list,
-				       &ring->gpu_write_list);
 			if (obj->pin_count) /* check for potential scanout */
 				intel_mark_busy(ring->dev, obj);
 		}

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -1002,7 +1002,6 @@ static int intel_init_ring_buffer(struct drm_device *dev,
 	ring->dev = dev;
 	INIT_LIST_HEAD(&ring->active_list);
 	INIT_LIST_HEAD(&ring->request_list);
-	INIT_LIST_HEAD(&ring->gpu_write_list);
 	ring->size = 32 * PAGE_SIZE;
 
 	init_waitqueue_head(&ring->irq_queue);
@@ -1473,7 +1472,6 @@ int intel_render_ring_init_dri(struct drm_device *dev, u64 start, u32 size)
 	ring->dev = dev;
 	INIT_LIST_HEAD(&ring->active_list);
 	INIT_LIST_HEAD(&ring->request_list);
-	INIT_LIST_HEAD(&ring->gpu_write_list);
 
 	ring->size = size;
 	ring->effective_size = ring->size;

drivers/gpu/drm/i915/intel_ringbuffer.h

@@ -100,15 +100,6 @@ struct  intel_ring_buffer {
 	 */
 	struct list_head request_list;
 
-	/**
-	 * List of objects currently pending a GPU write flush.
-	 *
-	 * All elements on this list will belong to either the
-	 * active_list or flushing_list, last_rendering_seqno can
-	 * be used to differentiate between the two elements.
-	 */
-	struct list_head gpu_write_list;
-
 	/**
 	 * Do we have some not yet emitted requests outstanding?
 	 */