1 files changed, 184 insertions, 154 deletions

diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
index 39bc4f54e272..2e9b38bdc33c 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.c
+++ b/drivers/gpu/drm/i915/i915_scheduler.c
@@ -35,109 +35,6 @@ static inline bool node_signaled(const struct i915_sched_node *node)
 	return i915_request_completed(node_to_request(node));
 }
 
-void i915_sched_node_init(struct i915_sched_node *node)
-{
-	INIT_LIST_HEAD(&node->signalers_list);
-	INIT_LIST_HEAD(&node->waiters_list);
-	INIT_LIST_HEAD(&node->link);
-	node->attr.priority = I915_PRIORITY_INVALID;
-	node->semaphores = 0;
-	node->flags = 0;
-}
-
-static struct i915_dependency *
-i915_dependency_alloc(void)
-{
-	return kmem_cache_alloc(global.slab_dependencies, GFP_KERNEL);
-}
-
-static void
-i915_dependency_free(struct i915_dependency *dep)
-{
-	kmem_cache_free(global.slab_dependencies, dep);
-}
-
-bool __i915_sched_node_add_dependency(struct i915_sched_node *node,
-				      struct i915_sched_node *signal,
-				      struct i915_dependency *dep,
-				      unsigned long flags)
-{
-	bool ret = false;
-
-	spin_lock_irq(&schedule_lock);
-
-	if (!node_signaled(signal)) {
-		INIT_LIST_HEAD(&dep->dfs_link);
-		list_add(&dep->wait_link, &signal->waiters_list);
-		list_add(&dep->signal_link, &node->signalers_list);
-		dep->signaler = signal;
-		dep->flags = flags;
-
-		/* Keep track of whether anyone on this chain has a semaphore */
-		if (signal->flags & I915_SCHED_HAS_SEMAPHORE_CHAIN &&
-		    !node_started(signal))
-			node->flags |= I915_SCHED_HAS_SEMAPHORE_CHAIN;
-
-		ret = true;
-	}
-
-	spin_unlock_irq(&schedule_lock);
-
-	return ret;
-}
-
-int i915_sched_node_add_dependency(struct i915_sched_node *node,
-				   struct i915_sched_node *signal)
-{
-	struct i915_dependency *dep;
-
-	dep = i915_dependency_alloc();
-	if (!dep)
-		return -ENOMEM;
-
-	if (!__i915_sched_node_add_dependency(node, signal, dep,
-					      I915_DEPENDENCY_ALLOC))
-		i915_dependency_free(dep);
-
-	return 0;
-}
-
-void i915_sched_node_fini(struct i915_sched_node *node)
-{
-	struct i915_dependency *dep, *tmp;
-
-	GEM_BUG_ON(!list_empty(&node->link));
-
-	spin_lock_irq(&schedule_lock);
-
-	/*
-	 * Everyone we depended upon (the fences we wait to be signaled)
-	 * should retire before us and remove themselves from our list.
-	 * However, retirement is run independently on each timeline and
-	 * so we may be called out-of-order.
-	 */
-	list_for_each_entry_safe(dep, tmp, &node->signalers_list, signal_link) {
-		GEM_BUG_ON(!node_signaled(dep->signaler));
-		GEM_BUG_ON(!list_empty(&dep->dfs_link));
-
-		list_del(&dep->wait_link);
-		if (dep->flags & I915_DEPENDENCY_ALLOC)
-			i915_dependency_free(dep);
-	}
-
-	/* Remove ourselves from everyone who depends upon us */
-	list_for_each_entry_safe(dep, tmp, &node->waiters_list, wait_link) {
-		GEM_BUG_ON(dep->signaler != node);
-		GEM_BUG_ON(!list_empty(&dep->dfs_link));
-
-		list_del(&dep->signal_link);
-		if (dep->flags & I915_DEPENDENCY_ALLOC)
-			i915_dependency_free(dep);
-	}
-
-	spin_unlock_irq(&schedule_lock);
-}
-
 static inline struct i915_priolist *to_priolist(struct rb_node *rb)
 {
 	return rb_entry(rb, struct i915_priolist, node);
@@ -180,7 +77,7 @@ i915_sched_lookup_priolist(struct intel_engine_cs *engine, int prio)
 	bool first = true;
 	int idx, i;
 
-	lockdep_assert_held(&engine->timeline.lock);
+	lockdep_assert_held(&engine->active.lock);
 	assert_priolists(execlists);
 
 	/* buckets sorted from highest [in slot 0] to lowest priority */
@@ -239,6 +136,11 @@ out:
 	return &p->requests[idx];
 }
 
+void __i915_priolist_free(struct i915_priolist *p)
+{
+	kmem_cache_free(global.slab_priorities, p);
+}
+
 struct sched_cache {
 	struct list_head *priolist;
 };
@@ -248,32 +150,52 @@ sched_lock_engine(const struct i915_sched_node *node,
 		  struct intel_engine_cs *locked,
 		  struct sched_cache *cache)
 {
-	struct intel_engine_cs *engine = node_to_request(node)->engine;
+	const struct i915_request *rq = node_to_request(node);
+	struct intel_engine_cs *engine;
 
 	GEM_BUG_ON(!locked);
 
-	if (engine != locked) {
-		spin_unlock(&locked->timeline.lock);
+	/*
+	 * Virtual engines complicate acquiring the engine timeline lock,
+	 * as their rq->engine pointer is not stable until under that
+	 * engine lock. The simple ploy we use is to take the lock then
+	 * check that the rq still belongs to the newly locked engine.
+	 */
+	while (locked != (engine = READ_ONCE(rq->engine))) {
+		spin_unlock(&locked->active.lock);
 		memset(cache, 0, sizeof(*cache));
-		spin_lock(&engine->timeline.lock);
+		spin_lock(&engine->active.lock);
+		locked = engine;
 	}
 
-	return engine;
+	GEM_BUG_ON(locked != engine);
+	return locked;
+}
+
+static inline int rq_prio(const struct i915_request *rq)
+{
+	return rq->sched.attr.priority | __NO_PREEMPTION;
 }
 
-static bool inflight(const struct i915_request *rq,
-		     const struct intel_engine_cs *engine)
+static void kick_submission(struct intel_engine_cs *engine, int prio)
 {
-	const struct i915_request *active;
+	const struct i915_request *inflight =
+		port_request(engine->execlists.port);
 
-	if (!i915_request_is_active(rq))
-		return false;
+	/*
+	 * If we are already the currently executing context, don't
+	 * bother evaluating if we should preempt ourselves, or if
+	 * we expect nothing to change as a result of running the
+	 * tasklet, i.e. we have not change the priority queue
+	 * sufficiently to oust the running context.
+	 */
+	if (!inflight || !i915_scheduler_need_preempt(prio, rq_prio(inflight)))
+		return;
 
-	active = port_request(engine->execlists.port);
-	return active->hw_context == rq->hw_context;
+	tasklet_hi_schedule(&engine->execlists.tasklet);
 }
 
-static void __i915_schedule(struct i915_request *rq,
+static void __i915_schedule(struct i915_sched_node *node,
 			    const struct i915_sched_attr *attr)
 {
 	struct intel_engine_cs *engine;
@@ -287,13 +209,13 @@ static void __i915_schedule(struct i915_request *rq,
 	lockdep_assert_held(&schedule_lock);
 	GEM_BUG_ON(prio == I915_PRIORITY_INVALID);
 
-	if (i915_request_completed(rq))
+	if (prio <= READ_ONCE(node->attr.priority))
 		return;
 
-	if (prio <= READ_ONCE(rq->sched.attr.priority))
+	if (node_signaled(node))
 		return;
 
-	stack.signaler = &rq->sched;
+	stack.signaler = node;
 	list_add(&stack.dfs_link, &dfs);
 
 	/*
@@ -344,9 +266,9 @@ static void __i915_schedule(struct i915_request *rq,
 	 * execlists_submit_request()), we can set our own priority and skip
 	 * acquiring the engine locks.
 	 */
-	if (rq->sched.attr.priority == I915_PRIORITY_INVALID) {
-		GEM_BUG_ON(!list_empty(&rq->sched.link));
-		rq->sched.attr = *attr;
+	if (node->attr.priority == I915_PRIORITY_INVALID) {
+		GEM_BUG_ON(!list_empty(&node->link));
+		node->attr = *attr;
 
 		if (stack.dfs_link.next == stack.dfs_link.prev)
 			return;
@@ -355,30 +277,27 @@ static void __i915_schedule(struct i915_request *rq,
 	}
 
 	memset(&cache, 0, sizeof(cache));
-	engine = rq->engine;
-	spin_lock(&engine->timeline.lock);
+	engine = node_to_request(node)->engine;
+	spin_lock(&engine->active.lock);
 
 	/* Fifo and depth-first replacement ensure our deps execute before us */
+	engine = sched_lock_engine(node, engine, &cache);
 	list_for_each_entry_safe_reverse(dep, p, &dfs, dfs_link) {
-		struct i915_sched_node *node = dep->signaler;
-
 		INIT_LIST_HEAD(&dep->dfs_link);
 
+		node = dep->signaler;
 		engine = sched_lock_engine(node, engine, &cache);
-		lockdep_assert_held(&engine->timeline.lock);
+		lockdep_assert_held(&engine->active.lock);
 
 		/* Recheck after acquiring the engine->timeline.lock */
 		if (prio <= node->attr.priority || node_signaled(node))
 			continue;
 
+		GEM_BUG_ON(node_to_request(node)->engine != engine);
+
 		node->attr.priority = prio;
-		if (!list_empty(&node->link)) {
-			if (!cache.priolist)
-				cache.priolist =
-					i915_sched_lookup_priolist(engine,
-								   prio);
-			list_move_tail(&node->link, cache.priolist);
-		} else {
+
+		if (list_empty(&node->link)) {
 			/*
 			 * If the request is not in the priolist queue because
 			 * it is not yet runnable, then it doesn't contribute
@@ -387,8 +306,16 @@ static void __i915_schedule(struct i915_request *rq,
 			 * queue; but in that case we may still need to reorder
 			 * the inflight requests.
 			 */
-			if (!i915_sw_fence_done(&node_to_request(node)->submit))
-				continue;
+			continue;
+		}
+
+		if (!intel_engine_is_virtual(engine) &&
+		    !i915_request_is_active(node_to_request(node))) {
+			if (!cache.priolist)
+				cache.priolist =
+					i915_sched_lookup_priolist(engine,
+								   prio);
+			list_move_tail(&node->link, cache.priolist);
 		}
 
 		if (prio <= engine->execlists.queue_priority_hint)
@@ -396,30 +323,30 @@ static void __i915_schedule(struct i915_request *rq,
 
 		engine->execlists.queue_priority_hint = prio;
 
-		/*
-		 * If we are already the currently executing context, don't
-		 * bother evaluating if we should preempt ourselves.
-		 */
-		if (inflight(node_to_request(node), engine))
-			continue;
-
 		/* Defer (tasklet) submission until after all of our updates. */
-		tasklet_hi_schedule(&engine->execlists.tasklet);
+		kick_submission(engine, prio);
 	}
 
-	spin_unlock(&engine->timeline.lock);
+	spin_unlock(&engine->active.lock);
 }
 
 void i915_schedule(struct i915_request *rq, const struct i915_sched_attr *attr)
 {
 	spin_lock_irq(&schedule_lock);
-	__i915_schedule(rq, attr);
+	__i915_schedule(&rq->sched, attr);
 	spin_unlock_irq(&schedule_lock);
 }
 
+static void __bump_priority(struct i915_sched_node *node, unsigned int bump)
+{
+	struct i915_sched_attr attr = node->attr;
+
+	attr.priority |= bump;
+	__i915_schedule(node, &attr);
+}
+
 void i915_schedule_bump_priority(struct i915_request *rq, unsigned int bump)
 {
-	struct i915_sched_attr attr;
 	unsigned long flags;
 
 	GEM_BUG_ON(bump & ~I915_PRIORITY_MASK);
@@ -428,17 +355,120 @@ void i915_schedule_bump_priority(struct i915_request *rq, unsigned int bump)
 		return;
 
 	spin_lock_irqsave(&schedule_lock, flags);
+	__bump_priority(&rq->sched, bump);
+	spin_unlock_irqrestore(&schedule_lock, flags);
+}
 
-	attr = rq->sched.attr;
-	attr.priority |= bump;
-	__i915_schedule(rq, &attr);
+void i915_sched_node_init(struct i915_sched_node *node)
+{
+	INIT_LIST_HEAD(&node->signalers_list);
+	INIT_LIST_HEAD(&node->waiters_list);
+	INIT_LIST_HEAD(&node->link);
+	node->attr.priority = I915_PRIORITY_INVALID;
+	node->semaphores = 0;
+	node->flags = 0;
+}
 
-	spin_unlock_irqrestore(&schedule_lock, flags);
+static struct i915_dependency *
+i915_dependency_alloc(void)
+{
+	return kmem_cache_alloc(global.slab_dependencies, GFP_KERNEL);
 }
 
-void __i915_priolist_free(struct i915_priolist *p)
+static void
+i915_dependency_free(struct i915_dependency *dep)
 {
-	kmem_cache_free(global.slab_priorities, p);
+	kmem_cache_free(global.slab_dependencies, dep);
+}
+
+bool __i915_sched_node_add_dependency(struct i915_sched_node *node,
+				      struct i915_sched_node *signal,
+				      struct i915_dependency *dep,
+				      unsigned long flags)
+{
+	bool ret = false;
+
+	spin_lock_irq(&schedule_lock);
+
+	if (!node_signaled(signal)) {
+		INIT_LIST_HEAD(&dep->dfs_link);
+		list_add(&dep->wait_link, &signal->waiters_list);
+		list_add(&dep->signal_link, &node->signalers_list);
+		dep->signaler = signal;
+		dep->flags = flags;
+
+		/* Keep track of whether anyone on this chain has a semaphore */
+		if (signal->flags & I915_SCHED_HAS_SEMAPHORE_CHAIN &&
+		    !node_started(signal))
+			node->flags |= I915_SCHED_HAS_SEMAPHORE_CHAIN;
+
+		/*
+		 * As we do not allow WAIT to preempt inflight requests,
+		 * once we have executed a request, along with triggering
+		 * any execution callbacks, we must preserve its ordering
+		 * within the non-preemptible FIFO.
+		 */
+		BUILD_BUG_ON(__NO_PREEMPTION & ~I915_PRIORITY_MASK);
+		if (flags & I915_DEPENDENCY_EXTERNAL)
+			__bump_priority(signal, __NO_PREEMPTION);
+
+		ret = true;
+	}
+
+	spin_unlock_irq(&schedule_lock);
+
+	return ret;
+}
+
+int i915_sched_node_add_dependency(struct i915_sched_node *node,
+				   struct i915_sched_node *signal)
+{
+	struct i915_dependency *dep;
+
+	dep = i915_dependency_alloc();
+	if (!dep)
+		return -ENOMEM;
+
+	if (!__i915_sched_node_add_dependency(node, signal, dep,
+					      I915_DEPENDENCY_EXTERNAL |
+					      I915_DEPENDENCY_ALLOC))
+		i915_dependency_free(dep);
+
+	return 0;
+}
+
+void i915_sched_node_fini(struct i915_sched_node *node)
+{
+	struct i915_dependency *dep, *tmp;
+
+	spin_lock_irq(&schedule_lock);
+
+	/*
+	 * Everyone we depended upon (the fences we wait to be signaled)
+	 * should retire before us and remove themselves from our list.
+	 * However, retirement is run independently on each timeline and
+	 * so we may be called out-of-order.
+	 */
+	list_for_each_entry_safe(dep, tmp, &node->signalers_list, signal_link) {
+		GEM_BUG_ON(!node_signaled(dep->signaler));
+		GEM_BUG_ON(!list_empty(&dep->dfs_link));
+
+		list_del(&dep->wait_link);
+		if (dep->flags & I915_DEPENDENCY_ALLOC)
+			i915_dependency_free(dep);
+	}
+
+	/* Remove ourselves from everyone who depends upon us */
+	list_for_each_entry_safe(dep, tmp, &node->waiters_list, wait_link) {
+		GEM_BUG_ON(dep->signaler != node);
+		GEM_BUG_ON(!list_empty(&dep->dfs_link));
+
+		list_del(&dep->signal_link);
+		if (dep->flags & I915_DEPENDENCY_ALLOC)
+			i915_dependency_free(dep);
+	}
+
+	spin_unlock_irq(&schedule_lock);
 }
 
 static void i915_global_scheduler_shrink(void)