[PATCH 51/72] drm/i915: Extract request submission from execlists

[Chris Wilson]

In the process of preparing to reuse the request submission logic for
other backends, lift it out of the execlists backend. It already
operates on the common structs, so just a matter of moving and renaming.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_lrc.c   | 55 +-----------------
 drivers/gpu/drm/i915/i915_scheduler.c | 82 +++++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_scheduler.h |  2 +
 3 files changed, 85 insertions(+), 54 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 24c9be137ba4..2da41ca0a6ba 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -3155,59 +3155,6 @@ static void execlists_preempt(struct timer_list *timer)
 	execlists_kick(timer, preempt);
 }
 
-static void queue_request(struct intel_engine_cs *engine,
-			  struct i915_request *rq)
-{
-	GEM_BUG_ON(!list_empty(&rq->sched.link));
-	list_add_tail(&rq->sched.link,
-		      i915_sched_lookup_priolist(engine, rq_prio(rq)));
-	set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
-}
-
-static bool submit_queue(struct intel_engine_cs *engine,
-			 const struct i915_request *rq)
-{
-	struct intel_engine_execlists *execlists = &engine->execlists;
-
-	if (rq_prio(rq) <= execlists->queue_priority_hint)
-		return false;
-
-	execlists->queue_priority_hint = rq_prio(rq);
-	return true;
-}
-
-static bool ancestor_on_hold(const struct intel_engine_cs *engine,
-			     const struct i915_request *rq)
-{
-	GEM_BUG_ON(i915_request_on_hold(rq));
-	return !list_empty(&engine->active.hold) && hold_request(rq);
-}
-
-static void execlists_submit_request(struct i915_request *request)
-{
-	struct intel_engine_cs *engine = request->engine;
-	unsigned long flags;
-
-	/* Will be called from irq-context when using foreign fences. */
-	spin_lock_irqsave(&engine->active.lock, flags);
-
-	if (unlikely(ancestor_on_hold(engine, request))) {
-		RQ_TRACE(request, "ancestor on hold\n");
-		list_add_tail(&request->sched.link, &engine->active.hold);
-		i915_request_set_hold(request);
-	} else {
-		queue_request(engine, request);
-
-		GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root));
-		GEM_BUG_ON(list_empty(&request->sched.link));
-
-		if (submit_queue(engine, request))
-			__execlists_kick(&engine->execlists);
-	}
-
-	spin_unlock_irqrestore(&engine->active.lock, flags);
-}
-
 static void __execlists_context_fini(struct intel_context *ce)
 {
 	intel_ring_put(ce->ring);
@@ -5018,7 +4965,7 @@ static void execlists_park(struct intel_engine_cs *engine)
 
 void intel_execlists_set_default_submission(struct intel_engine_cs *engine)
 {
-	engine->submit_request = execlists_submit_request;
+	engine->submit_request = i915_request_enqueue;
 	engine->execlists.tasklet.func = execlists_submission_tasklet;
 
 	engine->reset.prepare = execlists_reset_prepare;
diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
index 74533989a11d..9e006197c54b 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.c
+++ b/drivers/gpu/drm/i915/i915_scheduler.c
@@ -468,6 +468,88 @@ void i915_request_set_priority(struct i915_request *rq, int prio)
 	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
+static void queue_request(struct intel_engine_cs *engine,
+			  struct i915_request *rq)
+{
+	GEM_BUG_ON(!list_empty(&rq->sched.link));
+	list_add_tail(&rq->sched.link,
+		      i915_sched_lookup_priolist(engine, rq_prio(rq)));
+	set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
+}
+
+static bool submit_queue(struct intel_engine_cs *engine,
+			 const struct i915_request *rq)
+{
+	struct intel_engine_execlists *execlists = &engine->execlists;
+
+	if (rq_prio(rq) <= execlists->queue_priority_hint)
+		return false;
+
+	execlists->queue_priority_hint = rq_prio(rq);
+	return true;
+}
+
+static bool hold_request(const struct i915_request *rq)
+{
+	struct i915_dependency *p;
+	bool result = false;
+
+	/*
+	 * If one of our ancestors is on hold, we must also be put on hold,
+	 * otherwise we will bypass it and execute before it.
+	 */
+	rcu_read_lock();
+	for_each_signaler(p, rq) {
+		const struct i915_request *s =
+			container_of(p->signaler, typeof(*s), sched);
+
+		if (s->engine != rq->engine)
+			continue;
+
+		result = i915_request_on_hold(s);
+		if (result)
+			break;
+	}
+	rcu_read_unlock();
+
+	return result;
+}
+
+static bool ancestor_on_hold(const struct intel_engine_cs *engine,
+			     const struct i915_request *rq)
+{
+	GEM_BUG_ON(i915_request_on_hold(rq));
+	return unlikely(!list_empty(&engine->active.hold)) && hold_request(rq);
+}
+
+void i915_request_enqueue(struct i915_request *rq)
+{
+	struct intel_engine_cs *engine = rq->engine;
+	unsigned long flags;
+	bool kick = false;
+
+	/* Will be called from irq-context when using foreign fences. */
+	spin_lock_irqsave(&engine->active.lock, flags);
+	GEM_BUG_ON(test_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags));
+
+	if (unlikely(ancestor_on_hold(engine, rq))) {
+		RQ_TRACE(rq, "ancestor on hold\n");
+		list_add_tail(&rq->sched.link, &engine->active.hold);
+		i915_request_set_hold(rq);
+	} else {
+		queue_request(engine, rq);
+
+		GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root));
+
+		kick = submit_queue(engine, rq);
+	}
+
+	GEM_BUG_ON(list_empty(&rq->sched.link));
+	spin_unlock_irqrestore(&engine->active.lock, flags);
+	if (kick)
+		tasklet_hi_schedule(&engine->execlists.tasklet);
+}
+
 void i915_sched_node_init(struct i915_sched_node *node)
 {
 	spin_lock_init(&node->lock);
diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h
index b7a472263ffb..7befa7d03e08 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.h
+++ b/drivers/gpu/drm/i915/i915_scheduler.h
@@ -39,6 +39,8 @@ void i915_sched_init_ipi(struct i915_sched_ipi *ipi);
 
 void i915_request_set_priority(struct i915_request *request, int prio);
 
+void i915_request_enqueue(struct i915_request *request);
+
 struct list_head *
 i915_sched_lookup_priolist(struct intel_engine_cs *engine, int prio);
 
-- 
2.20.1