[PATCH 30/60] drm/i915: Extract request suspension from the execlists backend
Chris Wilson
chris at chris-wilson.co.uk
Sun Jan 3 22:39:27 UTC 2021
Make the ability to suspend and resume a request and its dependents
generic.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
.../drm/i915/gt/intel_execlists_submission.c | 148 +-----------------
drivers/gpu/drm/i915/i915_scheduler.c | 119 ++++++++++++++
drivers/gpu/drm/i915/i915_scheduler.h | 5 +
3 files changed, 128 insertions(+), 144 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index cf81e8215b5b..c25b8404f900 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -1885,166 +1885,26 @@ static void post_process_csb(struct i915_request **port,
execlists_schedule_out(*port++);
}
-static void __execlists_hold(struct i915_request *rq)
-{
- LIST_HEAD(list);
-
- do {
- struct i915_dependency *p;
-
- if (i915_request_is_active(rq))
- __i915_request_unsubmit(rq);
-
- clear_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
- list_move_tail(&rq->sched.link, &rq->engine->active.hold);
- i915_request_set_hold(rq);
- RQ_TRACE(rq, "on hold\n");
-
- for_each_waiter(p, rq) {
- struct i915_request *w =
- container_of(p->waiter, typeof(*w), sched);
-
- if (p->flags & I915_DEPENDENCY_WEAK)
- continue;
-
- /* Leave semaphores spinning on the other engines */
- if (w->engine != rq->engine)
- continue;
-
- if (!i915_request_is_ready(w))
- continue;
-
- if (__i915_request_is_complete(w))
- continue;
-
- if (i915_request_on_hold(w))
- continue;
-
- list_move_tail(&w->sched.link, &list);
- }
-
- rq = list_first_entry_or_null(&list, typeof(*rq), sched.link);
- } while (rq);
-}
-
static bool execlists_hold(struct intel_engine_cs *engine,
struct i915_request *rq)
{
+ bool result;
+
if (i915_request_on_hold(rq))
return false;
spin_lock_irq(&engine->active.lock);
-
- if (__i915_request_is_complete(rq)) { /* too late! */
- rq = NULL;
- goto unlock;
- }
-
- /*
- * Transfer this request onto the hold queue to prevent it
- * being resumbitted to HW (and potentially completed) before we have
- * released it. Since we may have already submitted following
- * requests, we need to remove those as well.
- */
- GEM_BUG_ON(i915_request_on_hold(rq));
- GEM_BUG_ON(rq->engine != engine);
- __execlists_hold(rq);
- GEM_BUG_ON(list_empty(&engine->active.hold));
-
-unlock:
+ result = __intel_engine_hold_request(engine, rq);
spin_unlock_irq(&engine->active.lock);
- return rq;
-}
-
-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 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 void __execlists_unhold(struct i915_request *rq)
-{
- LIST_HEAD(list);
-
- do {
- struct i915_dependency *p;
-
- RQ_TRACE(rq, "hold release\n");
-
- GEM_BUG_ON(!i915_request_on_hold(rq));
- GEM_BUG_ON(!i915_sw_fence_signaled(&rq->submit));
-
- i915_request_clear_hold(rq);
- list_move_tail(&rq->sched.link,
- i915_sched_lookup_priolist(rq->engine,
- rq_prio(rq)));
- set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
-
- /* Also release any children on this engine that are ready */
- for_each_waiter(p, rq) {
- struct i915_request *w =
- container_of(p->waiter, typeof(*w), sched);
-
- if (p->flags & I915_DEPENDENCY_WEAK)
- continue;
-
- /* Propagate any change in error status */
- if (rq->fence.error)
- i915_request_set_error_once(w, rq->fence.error);
-
- if (w->engine != rq->engine)
- continue;
-
- if (!i915_request_on_hold(w))
- continue;
-
- /* Check that no other parents are also on hold */
- if (hold_request(w))
- continue;
-
- list_move_tail(&w->sched.link, &list);
- }
-
- rq = list_first_entry_or_null(&list, typeof(*rq), sched.link);
- } while (rq);
-}
-
static void execlists_unhold(struct intel_engine_cs *engine,
struct i915_request *rq)
{
spin_lock_irq(&engine->active.lock);
-
- /*
- * Move this request back to the priority queue, and all of its
- * children and grandchildren that were suspended along with it.
- */
- __execlists_unhold(rq);
-
- if (rq_prio(rq) > engine->execlists.queue_priority_hint) {
- engine->execlists.queue_priority_hint = rq_prio(rq);
- tasklet_hi_schedule(&engine->execlists.tasklet);
- }
-
+ __intel_engine_unhold_request(engine, rq);
spin_unlock_irq(&engine->active.lock);
}
diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
index bd687c891ab6..7af2ce704be6 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.c
+++ b/drivers/gpu/drm/i915/i915_scheduler.c
@@ -574,6 +574,125 @@ __intel_engine_rewind_requests(struct intel_engine_cs *engine)
return active;
}
+bool __intel_engine_hold_request(struct intel_engine_cs *engine,
+ struct i915_request *rq)
+{
+ LIST_HEAD(list);
+
+ lockdep_assert_held(&engine->active.lock);
+ GEM_BUG_ON(i915_request_on_hold(rq));
+ GEM_BUG_ON(rq->engine != engine);
+
+ if (__i915_request_is_complete(rq)) /* too late! */
+ return false;
+
+ /*
+ * Transfer this request onto the hold queue to prevent it
+ * being resumbitted to HW (and potentially completed) before we have
+ * released it. Since we may have already submitted following
+ * requests, we need to remove those as well.
+ */
+ do {
+ struct i915_dependency *p;
+
+ if (i915_request_is_active(rq))
+ __i915_request_unsubmit(rq);
+
+ clear_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
+ list_move_tail(&rq->sched.link, &rq->engine->active.hold);
+ i915_request_set_hold(rq);
+ RQ_TRACE(rq, "on hold\n");
+
+ for_each_waiter(p, rq) {
+ struct i915_request *w =
+ container_of(p->waiter, typeof(*w), sched);
+
+ if (p->flags & I915_DEPENDENCY_WEAK)
+ continue;
+
+ /* Leave semaphores spinning on the other engines */
+ if (w->engine != engine)
+ continue;
+
+ if (!i915_request_is_ready(w))
+ continue;
+
+ if (__i915_request_is_complete(w))
+ continue;
+
+ if (i915_request_on_hold(w)) /* acts as a visited bit */
+ continue;
+
+ list_move_tail(&w->sched.link, &list);
+ }
+
+ rq = list_first_entry_or_null(&list, typeof(*rq), sched.link);
+ } while (rq);
+
+ GEM_BUG_ON(list_empty(&engine->active.hold));
+
+ return true;
+}
+
+void __intel_engine_unhold_request(struct intel_engine_cs *engine,
+ struct i915_request *rq)
+{
+ LIST_HEAD(list);
+
+ lockdep_assert_held(&engine->active.lock);
+
+ if (rq_prio(rq) > engine->execlists.queue_priority_hint) {
+ engine->execlists.queue_priority_hint = rq_prio(rq);
+ tasklet_hi_schedule(&engine->execlists.tasklet);
+ }
+
+ /*
+ * Move this request back to the priority queue, and all of its
+ * children and grandchildren that were suspended along with it.
+ */
+ do {
+ struct i915_dependency *p;
+
+ RQ_TRACE(rq, "hold release\n");
+
+ GEM_BUG_ON(!i915_request_on_hold(rq));
+ GEM_BUG_ON(!i915_sw_fence_signaled(&rq->submit));
+
+ i915_request_clear_hold(rq);
+ list_del_init(&rq->sched.link);
+
+ queue_request(engine, rq);
+
+ /* Also release any children on this engine that are ready */
+ for_each_waiter(p, rq) {
+ struct i915_request *w =
+ container_of(p->waiter, typeof(*w), sched);
+
+ if (p->flags & I915_DEPENDENCY_WEAK)
+ continue;
+
+ /* Propagate any change in error status */
+ if (rq->fence.error)
+ i915_request_set_error_once(w, rq->fence.error);
+
+ if (w->engine != engine)
+ continue;
+
+ /* We also treat the on-hold status as a visited bit */
+ if (!i915_request_on_hold(w))
+ continue;
+
+ /* Check that no other parents are also on hold [BFS] */
+ if (hold_request(w))
+ continue;
+
+ list_move_tail(&w->sched.link, &list);
+ }
+
+ rq = list_first_entry_or_null(&list, typeof(*rq), sched.link);
+ } while (rq);
+}
+
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 50fdc7168d38..b4b722982870 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.h
+++ b/drivers/gpu/drm/i915/i915_scheduler.h
@@ -44,6 +44,11 @@ void i915_request_enqueue(struct i915_request *request);
struct i915_request *
__intel_engine_rewind_requests(struct intel_engine_cs *engine);
+bool __intel_engine_hold_request(struct intel_engine_cs *engine,
+ struct i915_request *request);
+void __intel_engine_unhold_request(struct intel_engine_cs *engine,
+ struct i915_request *request);
+
struct list_head *
i915_sched_lookup_priolist(struct intel_engine_cs *engine, int prio);
--
2.20.1
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