[PATCH] drm/xe: Kill exec queues synchronously

[Matthew Brost]

Upon kill of exec queue ensure said exec queue is not running on the GPU
for overall safety by waiting for kill to complete. This includes
possibly waiting for a GT reset to complete.

Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Signed-off-by: Matthew Brost <matthew.brost at intel.com>
---
 drivers/gpu/drm/xe/xe_exec_queue_types.h |  6 +++++-
 drivers/gpu/drm/xe/xe_guc_submit.c       | 13 +++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_exec_queue_types.h b/drivers/gpu/drm/xe/xe_exec_queue_types.h
index 1408b02eea53..147e9407ce9b 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue_types.h
+++ b/drivers/gpu/drm/xe/xe_exec_queue_types.h
@@ -152,7 +152,11 @@ struct xe_exec_queue {
 struct xe_exec_queue_ops {
 	/** @init: Initialize exec queue for submission backend */
 	int (*init)(struct xe_exec_queue *q);
-	/** @kill: Kill inflight submissions for backend */
+	/**
+	 * @kill: Kill inflight submissions for backend, wait synchronously for
+	 * kill. For safety, should never be called while holding any locks as a
+	 * device reset may be last resort for kill.
+	 */
 	void (*kill)(struct xe_exec_queue *q);
 	/** @fini: Fini exec queue for submission backend */
 	void (*fini)(struct xe_exec_queue *q);
diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
index da2ead86b9ae..df03fdb83dbd 100644
--- a/drivers/gpu/drm/xe/xe_guc_submit.c
+++ b/drivers/gpu/drm/xe/xe_guc_submit.c
@@ -1496,10 +1496,23 @@ static int guc_exec_queue_init(struct xe_exec_queue *q)
 
 static void guc_exec_queue_kill(struct xe_exec_queue *q)
 {
+	struct xe_guc *guc = exec_queue_to_guc(q);
+	struct xe_device *xe = guc_to_xe(guc);
+	int ret;
+
 	trace_xe_exec_queue_kill(q);
 	set_exec_queue_killed(q);
 	__suspend_fence_signal(q);
 	xe_guc_exec_queue_trigger_cleanup(q);
+
+	ret = wait_event_timeout(guc->ct.wq,
+				 !exec_queue_pending_disable(q) ||
+				 guc_read_stopped(guc), HZ * 5);
+	if (!ret) {
+		drm_warn(&xe->drm, "Schedule disable failed to respond upon kill");
+		xe_gt_reset_async(q->gt);
+	}
+	xe_guc_submit_reset_wait(guc);
 }
 
 static void guc_exec_queue_add_msg(struct xe_exec_queue *q, struct xe_sched_msg *msg,
-- 
2.34.1