[Intel-gfx] [PATCH v4 32/38] drm/i915: Add scheduler support functions for TDR

[John.C.Harrison at Intel.com]

From: John Harrison <John.C.Harrison at Intel.com>

The TDR code needs to know what the scheduler is up to in order to
work out whether a ring is really hung or not.

v4: Removed some unnecessary braces to keep the style checker happy.

For: VIZ-1587
Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
---
 drivers/gpu/drm/i915/i915_scheduler.c | 30 ++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_scheduler.h |  1 +
 2 files changed, 31 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
index c93f69e..d19590c 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.c
+++ b/drivers/gpu/drm/i915/i915_scheduler.c
@@ -1461,6 +1461,36 @@ int i915_scheduler_closefile(struct drm_device *dev, struct drm_file *file)
 	return 0;
 }
 
+/*
+ * Used by TDR to distinguish hung rings (not moving but with work to do)
+ * from idle rings (not moving because there is nothing to do).
+ */
+bool i915_scheduler_is_ring_flying(struct intel_engine_cs *ring)
+{
+	struct drm_i915_private *dev_priv = ring->dev->dev_private;
+	struct i915_scheduler   *scheduler = dev_priv->scheduler;
+	struct i915_scheduler_queue_entry *node;
+	unsigned long   flags;
+	bool            found = false;
+
+	/* With the scheduler in bypass mode, no information can be returned. */
+	if (i915.scheduler_override & i915_so_direct_submit)
+		return true;
+
+	spin_lock_irqsave(&scheduler->lock, flags);
+
+	list_for_each_entry(node, &scheduler->node_queue[ring->id], link) {
+		if (I915_SQS_IS_FLYING(node)) {
+			found = true;
+			break;
+		}
+	}
+
+	spin_unlock_irqrestore(&scheduler->lock, flags);
+
+	return found;
+}
+
 bool i915_scheduler_file_queue_is_full(struct drm_file *file)
 {
 	struct drm_i915_file_private *file_priv = file->driver_priv;
diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h
index 1cf40fc..73bf321 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.h
+++ b/drivers/gpu/drm/i915/i915_scheduler.h
@@ -140,6 +140,7 @@ void        i915_gem_scheduler_clean_node(struct i915_scheduler_queue_entry *nod
 int         i915_scheduler_queue_execbuffer(struct i915_scheduler_queue_entry *qe);
 bool        i915_scheduler_notify_request(struct drm_i915_gem_request *req);
 void        i915_scheduler_wakeup(struct drm_device *dev);
+bool        i915_scheduler_is_ring_flying(struct intel_engine_cs *ring);
 void        i915_gem_scheduler_work_handler(struct work_struct *work);
 int         i915_scheduler_flush(struct intel_engine_cs *ring, bool is_locked);
 int         i915_scheduler_flush_stamp(struct intel_engine_cs *ring,
-- 
1.9.1