[PATCH] non-persistent soft exit

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c       | 15 +++++++++------
 drivers/gpu/drm/i915/gt/intel_context.h           | 10 ++++++++++
 drivers/gpu/drm/i915/gt/intel_context_types.h     |  1 +
 .../gpu/drm/i915/gt/intel_execlists_submission.c  | 14 ++++++++++++--
 4 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index fd8ee52e17a4..5a6eba1232cd 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -426,7 +426,8 @@ static struct intel_engine_cs *active_engine(struct intel_context *ce)
 	return engine;
 }
 
-static void kill_engines(struct i915_gem_engines *engines, bool ban)
+static void
+kill_engines(struct i915_gem_engines *engines, bool ban, bool persistent)
 {
 	struct i915_gem_engines_iter it;
 	struct intel_context *ce;
@@ -443,6 +444,8 @@ static void kill_engines(struct i915_gem_engines *engines, bool ban)
 
 		if (ban && intel_context_set_banned(ce))
 			continue;
+		else if (!persistent && intel_context_set_non_persistent(ce))
+			continue;
 
 		/*
 		 * Check the current active state of this context; if we
@@ -454,7 +457,7 @@ static void kill_engines(struct i915_gem_engines *engines, bool ban)
 		engine = active_engine(ce);
 
 		/* First attempt to gracefully cancel the context */
-		if (engine && !__cancel_engine(engine) && ban)
+		if (engine && !__cancel_engine(engine) && (ban || !persistent))
 			/*
 			 * If we are unable to send a preemptive pulse to bump
 			 * the context from the GPU, we have to resort to a full
@@ -466,8 +469,6 @@ static void kill_engines(struct i915_gem_engines *engines, bool ban)
 
 static void kill_context(struct i915_gem_context *ctx)
 {
-	bool ban = (!i915_gem_context_is_persistent(ctx) ||
-		    !ctx->i915->params.enable_hangcheck);
 	struct i915_gem_engines *pos, *next;
 
 	spin_lock_irq(&ctx->stale.lock);
@@ -480,7 +481,8 @@ static void kill_context(struct i915_gem_context *ctx)
 
 		spin_unlock_irq(&ctx->stale.lock);
 
-		kill_engines(pos, ban);
+		kill_engines(pos, !ctx->i915->params.enable_hangcheck,
+			     i915_gem_context_is_persistent(ctx));
 
 		spin_lock_irq(&ctx->stale.lock);
 		GEM_BUG_ON(i915_sw_fence_signaled(&pos->fence));
@@ -526,7 +528,8 @@ static void engines_idle_release(struct i915_gem_context *ctx,
 
 kill:
 	if (list_empty(&engines->link)) /* raced, already closed */
-		kill_engines(engines, true);
+		kill_engines(engines, true,
+			     i915_gem_context_is_persistent(ctx));
 
 	i915_sw_fence_commit(&engines->fence);
 }
diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index f83a73a2b39f..7d758bb13427 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -220,6 +220,16 @@ static inline bool intel_context_set_banned(struct intel_context *ce)
 	return test_and_set_bit(CONTEXT_BANNED, &ce->flags);
 }
 
+static inline bool intel_context_is_non_persistent(const struct intel_context *ce)
+{
+	return test_bit(CONTEXT_NON_PERSISTENT, &ce->flags);
+}
+
+static inline bool intel_context_set_non_persistent(struct intel_context *ce)
+{
+	return test_and_set_bit(CONTEXT_NON_PERSISTENT, &ce->flags);
+}
+
 static inline bool
 intel_context_force_single_submission(const struct intel_context *ce)
 {
diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index ed8c447a7346..aa949c539e93 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -95,6 +95,7 @@ struct intel_context {
 #define CONTEXT_BANNED			6
 #define CONTEXT_FORCE_SINGLE_SUBMISSION	7
 #define CONTEXT_NOPREEMPT		8
+#define CONTEXT_NON_PERSISTENT		9 /* Only if also closed. */
 
 	struct {
 		u64 timeout_us;
diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index de124870af44..55463797ff82 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -478,7 +478,9 @@ __execlists_schedule_in(struct i915_request *rq)
 		     !intel_engine_has_heartbeat(engine)))
 		intel_context_set_banned(ce);
 
-	if (unlikely(intel_context_is_banned(ce) || bad_request(rq)))
+	if (unlikely(intel_context_is_banned(ce) || bad_request(rq) ||
+		     (intel_context_is_closed(ce) &&
+		      intel_context_is_non_persistent(ce))))
 		reset_active(rq, engine);
 
 	if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
@@ -1204,12 +1206,20 @@ static void record_preemption(struct intel_engine_execlists *execlists)
 static unsigned long active_preempt_timeout(struct intel_engine_cs *engine,
 					    const struct i915_request *rq)
 {
+	struct intel_context *ce;
+
 	if (!rq)
 		return 0;
 
+	ce = rq->context;
+
 	/* Force a fast reset for terminated contexts (ignoring sysfs!) */
-	if (unlikely(intel_context_is_banned(rq->context) || bad_request(rq)))
+	if (unlikely(intel_context_is_banned(ce) || bad_request(rq)))
 		return 1;
+	/* Longer grace for closed non-persistent contexts to avoid resets. */
+	else if (unlikely(intel_context_is_closed(ce) &&
+			  intel_context_is_non_persistent(ce)))
+		return 15;
 
 	return READ_ONCE(engine->props.preempt_timeout_ms);
 }
-- 
2.30.2