[PATCH 31/75] drm/i915: Move timeslicing flag to scheduler

[Chris Wilson]

Whether a scheduler chooses to implement timeslicing is up to it, and
not an underlying property of the HW engine. The scheduler does depend
on the HW supporting preemption.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_engine.h         |  6 ++++++
 drivers/gpu/drm/i915/gt/intel_engine_types.h   | 18 ++++--------------
 .../drm/i915/gt/intel_execlists_submission.c   |  8 +++++---
 drivers/gpu/drm/i915/gt/selftest_execlists.c   |  2 +-
 drivers/gpu/drm/i915/i915_scheduler_types.h    | 10 ++++++++++
 5 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h
index 4f0163457aed..ca3a9cb06328 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine.h
@@ -279,4 +279,10 @@ intel_engine_flush_scheduler(struct intel_engine_cs *engine)
 	i915_sched_flush(intel_engine_get_scheduler(engine));
 }
 
+static inline bool
+intel_engine_has_timeslices(struct intel_engine_cs *engine)
+{
+	return i915_sched_has_timeslices(intel_engine_get_scheduler(engine));
+}
+
 #endif /* _INTEL_RINGBUFFER_H_ */
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h
index a3024a0de1de..96a0aec29672 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
@@ -442,11 +442,10 @@ struct intel_engine_cs {
 #define I915_ENGINE_SUPPORTS_STATS   BIT(1)
 #define I915_ENGINE_HAS_PREEMPTION   BIT(2)
 #define I915_ENGINE_HAS_SEMAPHORES   BIT(3)
-#define I915_ENGINE_HAS_TIMESLICES   BIT(4)
-#define I915_ENGINE_NEEDS_BREADCRUMB_TASKLET BIT(5)
-#define I915_ENGINE_IS_VIRTUAL       BIT(6)
-#define I915_ENGINE_HAS_RELATIVE_MMIO BIT(7)
-#define I915_ENGINE_REQUIRES_CMD_PARSER BIT(8)
+#define I915_ENGINE_NEEDS_BREADCRUMB_TASKLET BIT(4)
+#define I915_ENGINE_IS_VIRTUAL       BIT(5)
+#define I915_ENGINE_HAS_RELATIVE_MMIO BIT(6)
+#define I915_ENGINE_REQUIRES_CMD_PARSER BIT(7)
 	unsigned int flags;
 
 	/*
@@ -541,15 +540,6 @@ intel_engine_has_semaphores(const struct intel_engine_cs *engine)
 	return engine->flags & I915_ENGINE_HAS_SEMAPHORES;
 }
 
-static inline bool
-intel_engine_has_timeslices(const struct intel_engine_cs *engine)
-{
-	if (!IS_ACTIVE(CONFIG_DRM_I915_TIMESLICE_DURATION))
-		return false;
-
-	return engine->flags & I915_ENGINE_HAS_TIMESLICES;
-}
-
 static inline bool
 intel_engine_needs_breadcrumb_tasklet(const struct intel_engine_cs *engine)
 {
diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index 8a06794d1d6b..7ef12c72ce12 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -1020,7 +1020,7 @@ static bool needs_timeslice(const struct intel_engine_cs *engine,
 {
 	const struct i915_sched *se = &engine->sched;
 
-	if (!intel_engine_has_timeslices(engine))
+	if (!i915_sched_has_timeslices(se))
 		return false;
 
 	/* If not currently active, or about to switch, wait for next event */
@@ -2939,8 +2939,6 @@ logical_ring_default_vfuncs(struct intel_engine_cs *engine)
 		engine->flags |= I915_ENGINE_HAS_SEMAPHORES;
 		if (can_preempt(engine)) {
 			engine->flags |= I915_ENGINE_HAS_PREEMPTION;
-			if (IS_ACTIVE(CONFIG_DRM_I915_TIMESLICE_DURATION))
-				engine->flags |= I915_ENGINE_HAS_TIMESLICES;
 		}
 	}
 
@@ -3006,6 +3004,10 @@ static void init_execlists(struct intel_engine_cs *engine)
 	__set_bit(I915_SCHED_ACTIVE_BIT, &engine->sched.flags);
 	__set_bit(I915_SCHED_PRIORITY_BIT, &engine->sched.flags);
 
+	if (IS_ACTIVE(CONFIG_DRM_I915_TIMESLICE_DURATION) &&
+	    intel_engine_has_preemption(engine))
+		__set_bit(I915_SCHED_TIMESLICE_BIT, &engine->sched.flags);
+
 	timer_setup(&engine->execlists.timer, execlists_timeslice, 0);
 	timer_setup(&engine->execlists.preempt, execlists_preempt, 0);
 
diff --git a/drivers/gpu/drm/i915/gt/selftest_execlists.c b/drivers/gpu/drm/i915/gt/selftest_execlists.c
index cfc0f4b9fbc5..147cbfd6dec0 100644
--- a/drivers/gpu/drm/i915/gt/selftest_execlists.c
+++ b/drivers/gpu/drm/i915/gt/selftest_execlists.c
@@ -3825,7 +3825,7 @@ static unsigned int
 __select_siblings(struct intel_gt *gt,
 		  unsigned int class,
 		  struct intel_engine_cs **siblings,
-		  bool (*filter)(const struct intel_engine_cs *))
+		  bool (*filter)(struct intel_engine_cs *))
 {
 	unsigned int n = 0;
 	unsigned int inst;
diff --git a/drivers/gpu/drm/i915/i915_scheduler_types.h b/drivers/gpu/drm/i915/i915_scheduler_types.h
index 1fe60e5b3173..b9f60366262e 100644
--- a/drivers/gpu/drm/i915/i915_scheduler_types.h
+++ b/drivers/gpu/drm/i915/i915_scheduler_types.h
@@ -12,6 +12,7 @@
 #include <linux/workqueue.h>
 
 #include "i915_priolist_types.h"
+#include "i915_utils.h"
 
 struct drm_printer;
 struct i915_request;
@@ -21,6 +22,7 @@ enum {
 	I915_SCHED_ENABLE_BIT = 0,
 	I915_SCHED_ACTIVE_BIT,
 	I915_SCHED_PRIORITY_BIT, /* priority sorting of queue */
+	I915_SCHED_TIMESLICE_BIT, /* multitasking for long workloads */
 };
 
 /**
@@ -196,4 +198,12 @@ static inline bool i915_sched_has_priorities(const struct i915_sched *se)
 	return test_bit(I915_SCHED_PRIORITY_BIT, &se->flags);
 }
 
+static inline bool i915_sched_has_timeslices(const struct i915_sched *se)
+{
+	if (!IS_ACTIVE(CONFIG_DRM_I915_TIMESLICE_DURATION))
+		return false;
+
+	return test_bit(I915_SCHED_TIMESLICE_BIT, &se->flags);
+}
+
 #endif /* _I915_SCHEDULER_TYPES_H_ */
-- 
2.20.1