drm/i915: Move active request tracking to a vfunc

Move active request tracking to a backend vfunc rather than assuming all
backends want to do this in the manner. In the of case execlists /
ring submission the tracking is on the physical engine while with GuC
submission it is on the context.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727002348.97202-8-matthew.brost@intel.com

1 files changed, 40 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index 6e4959ee5065..b4a876736074 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -3157,6 +3157,42 @@ static void execlists_park(struct intel_engine_cs *engine)
 	cancel_timer(&engine->execlists.preempt);
 }
 
+static void add_to_engine(struct i915_request *rq)
+{
+	lockdep_assert_held(&rq->engine->sched_engine->lock);
+	list_move_tail(&rq->sched.link, &rq->engine->sched_engine->requests);
+}
+
+static void remove_from_engine(struct i915_request *rq)
+{
+	struct intel_engine_cs *engine, *locked;
+
+	/*
+	 * 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.
+	 */
+	locked = READ_ONCE(rq->engine);
+	spin_lock_irq(&locked->sched_engine->lock);
+	while (unlikely(locked != (engine = READ_ONCE(rq->engine)))) {
+		spin_unlock(&locked->sched_engine->lock);
+		spin_lock(&engine->sched_engine->lock);
+		locked = engine;
+	}
+	list_del_init(&rq->sched.link);
+
+	clear_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
+	clear_bit(I915_FENCE_FLAG_HOLD, &rq->fence.flags);
+
+	/* Prevent further __await_execution() registering a cb, then flush */
+	set_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags);
+
+	spin_unlock_irq(&locked->sched_engine->lock);
+
+	i915_request_notify_execute_cb_imm(rq);
+}
+
 static bool can_preempt(struct intel_engine_cs *engine)
 {
 	if (GRAPHICS_VER(engine->i915) > 8)
@@ -3251,6 +3287,8 @@ logical_ring_default_vfuncs(struct intel_engine_cs *engine)
 
 	engine->cops = &execlists_context_ops;
 	engine->request_alloc = execlists_request_alloc;
+	engine->add_active_request = add_to_engine;
+	engine->remove_active_request = remove_from_engine;
 
 	engine->reset.prepare = execlists_reset_prepare;
 	engine->reset.rewind = execlists_reset_rewind;
@@ -3847,6 +3885,8 @@ execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count)
 			 "v%dx%d", ve->base.class, count);
 		ve->base.context_size = sibling->context_size;
 
+		ve->base.add_active_request = sibling->add_active_request;
+		ve->base.remove_active_request = sibling->remove_active_request;
 		ve->base.emit_bb_start = sibling->emit_bb_start;
 		ve->base.emit_flush = sibling->emit_flush;
 		ve->base.emit_init_breadcrumb = sibling->emit_init_breadcrumb;