[PATCH 5/5] drm/i915: Add locking to intel_context_unpin

[Maarten Lankhorst]

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
 drivers/gpu/drm/i915/gt/intel_context.c | 68 ++++++++++++++++++++++---
 drivers/gpu/drm/i915/gt/intel_context.h |  7 +--
 2 files changed, 63 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index b630c1968794..b27731ce8c11 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -286,11 +286,8 @@ int __intel_context_do_pin(struct intel_context *ce)
 	return err;
 }
 
-void intel_context_unpin(struct intel_context *ce)
+static void __intel_context_unpin(struct intel_context *ce)
 {
-	if (!atomic_dec_and_test(&ce->pin_count))
-		return;
-
 	CE_TRACE(ce, "unpin\n");
 	ce->ops->unpin(ce);
 
@@ -305,16 +302,75 @@ void intel_context_unpin(struct intel_context *ce)
 	intel_context_put(ce);
 }
 
+void intel_context_unpin(struct intel_context *ce)
+{
+	if (!atomic_dec_and_test(&ce->pin_count))
+		return;
+
+	__intel_context_unpin(ce);
+}
+
+void intel_context_unpin_unlocked(struct intel_context *ce)
+{
+	struct i915_gem_ww_ctx ww;
+	int err;
+
+	if (!atomic_dec_and_test(&ce->pin_count))
+		return;
+
+	i915_gem_ww_ctx_init(&ww, false);
+retry:
+	err = i915_gem_object_lock(ce->timeline->hwsp_ggtt->obj, &ww);
+	if (!err && ce->ring->vma->obj)
+		err = i915_gem_object_lock(ce->ring->vma->obj, &ww);
+	if (!err && ce->state)
+		err = i915_gem_object_lock(ce->state->obj, &ww);
+
+	if (!err)
+		__intel_context_unpin(ce);
+
+	if (err == -EDEADLK) {
+		err = i915_gem_ww_ctx_backoff(&ww);
+		if (!err)
+			goto retry;
+	}
+	i915_gem_ww_ctx_fini(&ww);
+
+	GEM_WARN_ON(err);
+}
+
 static void __intel_context_retire(struct i915_active *active)
 {
 	struct intel_context *ce = container_of(active, typeof(*ce), active);
+	struct i915_gem_ww_ctx ww;
+	int err;
 
 	CE_TRACE(ce, "retire runtime: { total:%lluns, avg:%lluns }\n",
 		 intel_context_get_total_runtime_ns(ce),
 		 intel_context_get_avg_runtime_ns(ce));
 
 	set_bit(CONTEXT_VALID_BIT, &ce->flags);
-	intel_context_post_unpin(ce);
+
+	i915_gem_ww_ctx_init(&ww, false);
+retry:
+	err = i915_gem_object_lock(ce->timeline->hwsp_ggtt->obj, &ww);
+	if (!err && ce->ring->vma->obj)
+		err = i915_gem_object_lock(ce->ring->vma->obj, &ww);
+	if (!err && ce->state)
+		err = i915_gem_object_lock(ce->state->obj, &ww);
+
+	if (!err)
+		intel_context_post_unpin(ce);
+
+	if (err == -EDEADLK) {
+		err = i915_gem_ww_ctx_backoff(&ww);
+		if (!err)
+			goto retry;
+	}
+	i915_gem_ww_ctx_fini(&ww);
+
+	GEM_WARN_ON(err);
+
 	intel_context_put(ce);
 }
 
@@ -363,7 +419,7 @@ intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
 	mutex_init(&ce->alloc_mutex);
 
 	i915_active_init(&ce->active,
-			 __intel_context_active, __intel_context_retire, 0);
+			 __intel_context_active, __intel_context_retire, I915_ACTIVE_RETIRE_SLEEPS);
 }
 
 void intel_context_fini(struct intel_context *ce)
diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index 4cf6901fcb81..45fea2e82637 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -116,13 +116,8 @@ static inline int intel_context_pin_ww(struct intel_context *ce,
 	return __intel_context_do_pin_ww(ce, ww);
 }
 
-static inline void __intel_context_pin(struct intel_context *ce)
-{
-	GEM_BUG_ON(!intel_context_is_pinned(ce));
-	atomic_inc(&ce->pin_count);
-}
-
 void intel_context_unpin(struct intel_context *ce);
+void intel_context_unpin_unlocked(struct intel_context *ce);
 
 void intel_context_enter_engine(struct intel_context *ce);
 void intel_context_exit_engine(struct intel_context *ce);
-- 
2.31.0