[PATCH 35/58] drm/i915: Move preempt-reset flag to the scheduler

[Chris Wilson]

While the HW may support preemption, whether or not the scheduler
enforces preemption by forcibly resetting the current context is
ultimately up to the scheduler.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_engine.h               | 7 ++-----
 drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 5 ++++-
 drivers/gpu/drm/i915/i915_scheduler_types.h          | 9 +++++++++
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h
index 7be580ae4c90..4a7f1ede11fc 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine.h
@@ -238,12 +238,9 @@ void intel_engine_init_active(struct intel_engine_cs *engine,
 #define ENGINE_VIRTUAL	2
 
 static inline bool
-intel_engine_has_preempt_reset(const struct intel_engine_cs *engine)
+intel_engine_has_preempt_reset(struct intel_engine_cs *engine)
 {
-	if (!IS_ACTIVE(CONFIG_DRM_I915_PREEMPT_TIMEOUT))
-		return false;
-
-	return intel_engine_has_preemption(engine);
+	return i915_sched_has_preempt_reset(intel_engine_get_scheduler(engine));
 }
 
 static inline bool
diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index e72dd64b9bbe..2e2e4cb237c5 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -2936,9 +2936,12 @@ logical_ring_default_vfuncs(struct intel_engine_cs *engine)
 		__set_bit(I915_SCHED_HAS_TIMESLICES_BIT,
 			  &engine->sched.flags);
 
-	if (intel_engine_has_preemption(engine))
+	if (intel_engine_has_preemption(engine)) {
 		__set_bit(I915_SCHED_USE_BUSYWAIT_BIT,
 			  &engine->sched.flags);
+		__set_bit(I915_SCHED_HAS_PREEMPT_RESET_BIT,
+			  &engine->sched.flags);
+	}
 }
 
 static void logical_ring_default_irqs(struct intel_engine_cs *engine)
diff --git a/drivers/gpu/drm/i915/i915_scheduler_types.h b/drivers/gpu/drm/i915/i915_scheduler_types.h
index 1b0f6beecad4..0b4cbee948ec 100644
--- a/drivers/gpu/drm/i915/i915_scheduler_types.h
+++ b/drivers/gpu/drm/i915/i915_scheduler_types.h
@@ -20,6 +20,7 @@ struct i915_request;
 enum {
 	I915_SCHED_ACTIVE_BIT = 0,
 	I915_SCHED_HAS_TIMESLICES_BIT,
+	I915_SCHED_HAS_PREEMPT_RESET_BIT,
 	I915_SCHED_NEEDS_BREADCRUMB_BIT,
 	I915_SCHED_USE_BUSYWAIT_BIT,
 };
@@ -206,4 +207,12 @@ static inline bool i915_sched_use_busywait(const struct i915_sched *se)
 	return test_bit(I915_SCHED_USE_BUSYWAIT_BIT, &se->flags);
 }
 
+static inline bool i915_sched_has_preempt_reset(const struct i915_sched *se)
+{
+	if (!IS_ACTIVE(CONFIG_DRM_I915_PREEMPT_TIMEOUT))
+		return false;
+
+	return test_bit(I915_SCHED_HAS_PREEMPT_RESET_BIT, &se->flags);
+}
+
 #endif /* _I915_SCHEDULER_TYPES_H_ */
-- 
2.20.1