review for danvetscheduler_blocking

3 files changed, 78 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 15c0ca58ad8b..de6b0c2c5a5f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1189,6 +1189,8 @@ int __must_check i915_add_request(struct intel_ring_buffer *ring,
 				  struct drm_i915_gem_request *request);
 int __must_check i915_wait_request(struct intel_ring_buffer *ring,
 				   uint32_t seqno);
+int __must_check i915_gem_wait_unlocked(struct intel_ring_buffer *ring,
+					uint32_t seqno);
 int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
 int __must_check
 i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index f0f885f44b87..07e1be746fc7 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2031,6 +2031,36 @@ i915_wait_request(struct intel_ring_buffer *ring,
 	return ret;
 }
 
+int
+i915_gem_wait_unlocked(struct intel_ring_buffer *ring,
+		       uint32_t seqno)
+{
+	struct drm_i915_private *dev_priv = ring->dev->dev_private;
+	int ret;
+
+	if (i915_seqno_passed(ring->get_seqno(ring), seqno))
+		return 0;
+
+	do {
+		/* yes it's racy, so we wake up pretty often to check... not
+		 * power friendly. */
+		ret = wait_event_interruptible_timeout(ring->irq_queue,
+			i915_seqno_passed(ring->get_seqno(ring), seqno) ||
+			dev_priv->mm.suspended ||
+			atomic_read(&dev_priv->mm.wedged),
+			msecs_to_jiffies(1));
+
+		if (atomic_read(&dev_priv->mm.wedged))
+			BUG_ON(ret == 0);
+
+		if (dev_priv->mm.suspended)
+			return -EBUSY;
+
+	} while (ret == 0);
+
+	return 0;
+}
+
 /**
  * Ensures that all rendering to the object has completed and the object is
  * safe to unbind from the GTT or access from the CPU.
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 7b23d94e8d56..6d780c5a1417 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -43,6 +43,8 @@ struct change_domains {
 struct eb_objects {
 	struct drm_i915_gem_object *batch_obj;
 	struct list_head objects;
+	uint32_t seqno;
+	struct intel_ring_buffer *wait_ring;
 	int buffer_count;
 	int mode;
 	int and;
@@ -276,6 +278,33 @@ eb_get_object(struct eb_objects *eb, unsigned long handle)
 	return NULL;
 }
 
+static uint32_t
+eb_would_block(struct eb_objects *eb)
+{
+	struct drm_i915_gem_object *obj;
+	uint32_t seqno, last_seqno = 0;
+	/* Let's see if this thing would have to block */
+	list_for_each_entry(obj, &eb->objects, exec_list) {
+		/* It's on an active list, and not our ring */
+		seqno = obj->last_rendering_seqno;
+		if (seqno == 0)
+			continue;
+
+		if (seqno < obj->ring->outstanding_lazy_request)
+			continue;
+
+		if (obj->ring == eb->batch_obj->ring)
+			continue;
+
+		if (last_seqno < seqno) {
+			eb->wait_ring = obj->ring;
+			last_seqno = seqno;
+		}
+	}
+
+	return last_seqno;
+}
+
 static void
 eb_destroy(struct eb_objects *eb)
 {
@@ -1037,6 +1066,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 	struct drm_i915_gem_object *obj = NULL;
 	struct drm_clip_rect *cliprects = NULL;
 	struct intel_ring_buffer *ring;
+	bool rt_prio = false;
 	u32 exec_start, exec_len;
 	u32 seqno;
 	int ret, i;
@@ -1119,6 +1149,10 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 		goto pre_mutex_err;
 	}
 
+	rt_prio = (args->flags & I915_EXEC_PRIORITY_CLASS_MASK) ==
+		   I915_EXEC_PRIO_CLASS_REALTIME;
+
+again:
 	for (i = 0; i < args->buffer_count; i++) {
 		obj = to_intel_bo(drm_gem_object_lookup(dev, file,
 							exec[i].handle));
@@ -1145,6 +1179,18 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 	/* The last object is the batch object */
 	eb->batch_obj = obj;
 
+	if (eb_would_block(eb) && !rt_prio) {
+		/* Drop the lock and wait for the seqno */
+		eb_reset(eb);
+		mutex_unlock(&dev->struct_mutex);
+		ret = i915_gem_wait_unlocked(ring, eb->seqno);
+		if (ret || i915_mutex_lock_interruptible(dev)) {
+			eb_destroy(eb);
+			goto pre_mutex_err;
+		}
+		goto again;
+	}
+
 	/* Move the objects en-masse into the GTT, evicting if necessary. */
 	ret = i915_gem_execbuffer_reserve(ring, file, &eb->objects);
 	if (ret)