[Intel-gfx] [PATCH 098/190] drm/i915: Double check the active status on the batch pool

[Chris Wilson]

We should not rely on obj->active being uptodate unless we manually
flush it. Instead, we can verify that the next available batch object is
idle by looking at its last active request (and checking it for
completion).

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem_batch_pool.c | 24 ++++++++++++++++--------
 drivers/gpu/drm/i915/i915_gem_batch_pool.h |  7 +++++--
 drivers/gpu/drm/i915/intel_lrc.c           |  2 +-
 drivers/gpu/drm/i915/intel_ringbuffer.c    |  2 +-
 4 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_batch_pool.c b/drivers/gpu/drm/i915/i915_gem_batch_pool.c
index 7bf2f3f2968e..d4318665ac6c 100644
--- a/drivers/gpu/drm/i915/i915_gem_batch_pool.c
+++ b/drivers/gpu/drm/i915/i915_gem_batch_pool.c
@@ -41,15 +41,15 @@
 
 /**
  * i915_gem_batch_pool_init() - initialize a batch buffer pool
- * @dev: the drm device
+ * @engine: the associated request submission engine
  * @pool: the batch buffer pool
  */
-void i915_gem_batch_pool_init(struct drm_device *dev,
+void i915_gem_batch_pool_init(struct intel_engine_cs *engine,
 			      struct i915_gem_batch_pool *pool)
 {
 	int n;
 
-	pool->dev = dev;
+	pool->engine = engine;
 
 	for (n = 0; n < ARRAY_SIZE(pool->cache_list); n++)
 		INIT_LIST_HEAD(&pool->cache_list[n]);
@@ -65,7 +65,7 @@ void i915_gem_batch_pool_fini(struct i915_gem_batch_pool *pool)
 {
 	int n;
 
-	WARN_ON(!mutex_is_locked(&pool->dev->struct_mutex));
+	lockdep_assert_held(&pool->engine->dev->struct_mutex);
 
 	for (n = 0; n < ARRAY_SIZE(pool->cache_list); n++) {
 		while (!list_empty(&pool->cache_list[n])) {
@@ -102,7 +102,7 @@ i915_gem_batch_pool_get(struct i915_gem_batch_pool *pool,
 	struct list_head *list;
 	int n;
 
-	WARN_ON(!mutex_is_locked(&pool->dev->struct_mutex));
+	lockdep_assert_held(&pool->engine->dev->struct_mutex);
 
 	/* Compute a power-of-two bucket, but throw everything greater than
 	 * 16KiB into the same bucket: i.e. the the buckets hold objects of
@@ -115,8 +115,16 @@ i915_gem_batch_pool_get(struct i915_gem_batch_pool *pool,
 
 	list_for_each_entry_safe(tmp, next, list, batch_pool_link) {
 		/* The batches are strictly LRU ordered */
-		if (tmp->active)
-			break;
+		if (tmp->active) {
+			struct drm_i915_gem_request *rq;
+
+			rq = tmp->last_read[pool->engine->id].request;
+			if (!i915_gem_request_completed(rq))
+				break;
+
+			GEM_BUG_ON(tmp->active & ~intel_engine_flag(pool->engine));
+			GEM_BUG_ON(tmp->last_write.request);
+		}
 
 		/* While we're looping, do some clean up */
 		if (tmp->madv == __I915_MADV_PURGED) {
@@ -134,7 +142,7 @@ i915_gem_batch_pool_get(struct i915_gem_batch_pool *pool,
 	if (obj == NULL) {
 		int ret;
 
-		obj = i915_gem_alloc_object(pool->dev, size);
+		obj = i915_gem_alloc_object(pool->engine->dev, size);
 		if (obj == NULL)
 			return ERR_PTR(-ENOMEM);
 
diff --git a/drivers/gpu/drm/i915/i915_gem_batch_pool.h b/drivers/gpu/drm/i915/i915_gem_batch_pool.h
index 848e90703eed..7fd4df0a29fe 100644
--- a/drivers/gpu/drm/i915/i915_gem_batch_pool.h
+++ b/drivers/gpu/drm/i915/i915_gem_batch_pool.h
@@ -27,13 +27,16 @@
 
 #include "i915_drv.h"
 
+struct drm_device;
+struct intel_engine_cs;
+
 struct i915_gem_batch_pool {
-	struct drm_device *dev;
+	struct intel_engine_cs *engine;
 	struct list_head cache_list[4];
 };
 
 /* i915_gem_batch_pool.c */
-void i915_gem_batch_pool_init(struct drm_device *dev,
+void i915_gem_batch_pool_init(struct intel_engine_cs *engine,
 			      struct i915_gem_batch_pool *pool);
 void i915_gem_batch_pool_fini(struct i915_gem_batch_pool *pool);
 struct drm_i915_gem_object*
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 3a2088f9d0be..850cacdf6dda 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1444,7 +1444,7 @@ static int logical_ring_init(struct drm_device *dev, struct intel_engine_cs *rin
 	ring->i915 = dev_priv;
 	ring->fence_context = fence_context_alloc(1);
 	INIT_LIST_HEAD(&ring->request_list);
-	i915_gem_batch_pool_init(dev, &ring->batch_pool);
+	i915_gem_batch_pool_init(ring, &ring->batch_pool);
 	intel_engine_init_breadcrumbs(ring);
 
 	INIT_LIST_HEAD(&ring->buffers);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 7ca4e1fc854d..09799ce72212 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2028,7 +2028,7 @@ static int intel_init_engine(struct drm_device *dev,
 	INIT_LIST_HEAD(&engine->request_list);
 	INIT_LIST_HEAD(&engine->execlist_queue);
 	INIT_LIST_HEAD(&engine->buffers);
-	i915_gem_batch_pool_init(dev, &engine->batch_pool);
+	i915_gem_batch_pool_init(engine, &engine->batch_pool);
 	memset(engine->semaphore.sync_seqno, 0, sizeof(engine->semaphore.sync_seqno));
 
 	intel_engine_init_breadcrumbs(engine);
-- 
2.7.0.rc3