[PATCH v2] drm/xe: Use RCU free for exec queue, not GuC exec queue

[Matthew Brost]

The exec queue name is used in dma-fence timelines, not the GuC exec queue.
Therefore, the exec queue itself requires RCU freeing rather than the
GuC exec queue.

Fixes: 6bd90e700b42 ("drm/xe: Make dma-fences compliant with the safe access rules")
Cc: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
Cc: stable at vger.kernel.org
Signed-off-by: Matthew Brost <matthew.brost at intel.com>
---
 drivers/gpu/drm/xe/xe_exec_queue.c           | 7 ++++++-
 drivers/gpu/drm/xe/xe_exec_queue_types.h     | 2 ++
 drivers/gpu/drm/xe/xe_guc_exec_queue_types.h | 2 --
 drivers/gpu/drm/xe/xe_guc_submit.c           | 7 +------
 4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c
index fee22358cc09..d8c3e983ffb6 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue.c
+++ b/drivers/gpu/drm/xe/xe_exec_queue.c
@@ -47,7 +47,11 @@ static void __xe_exec_queue_free(struct xe_exec_queue *q)
 	if (q->xef)
 		xe_file_put(q->xef);
 
-	kfree(q);
+	/*
+	 * RCU free due sched being exported via DRM scheduler fences
+	 * (timeline name).
+	 */
+	kfree_rcu(q, rcu);
 }
 
 static struct xe_exec_queue *__xe_exec_queue_alloc(struct xe_device *xe,
@@ -82,6 +86,7 @@ static struct xe_exec_queue *__xe_exec_queue_alloc(struct xe_device *xe,
 	INIT_LIST_HEAD(&q->multi_gt_link);
 	INIT_LIST_HEAD(&q->hw_engine_group_link);
 	INIT_LIST_HEAD(&q->pxp.link);
+	init_rcu_head(&q->rcu);
 
 	q->sched_props.timeslice_us = hwe->eclass->sched_props.timeslice_us;
 	q->sched_props.preempt_timeout_us =
diff --git a/drivers/gpu/drm/xe/xe_exec_queue_types.h b/drivers/gpu/drm/xe/xe_exec_queue_types.h
index cc1cffb5c87f..a17fe852fc0d 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue_types.h
+++ b/drivers/gpu/drm/xe/xe_exec_queue_types.h
@@ -43,6 +43,8 @@ struct xe_exec_queue {
 
 	/** @gt: GT structure this exec queue can submit to */
 	struct xe_gt *gt;
+	/** @rcu: For safe freeing of exported dma fences */
+	struct rcu_head rcu;
 	/**
 	 * @hwe: A hardware of the same class. May (physical engine) or may not
 	 * (virtual engine) be where jobs actual engine up running. Should never
diff --git a/drivers/gpu/drm/xe/xe_guc_exec_queue_types.h b/drivers/gpu/drm/xe/xe_guc_exec_queue_types.h
index a3f421e2adc0..4c39f01e4f52 100644
--- a/drivers/gpu/drm/xe/xe_guc_exec_queue_types.h
+++ b/drivers/gpu/drm/xe/xe_guc_exec_queue_types.h
@@ -20,8 +20,6 @@ struct xe_exec_queue;
 struct xe_guc_exec_queue {
 	/** @q: Backpointer to parent xe_exec_queue */
 	struct xe_exec_queue *q;
-	/** @rcu: For safe freeing of exported dma fences */
-	struct rcu_head rcu;
 	/** @sched: GPU scheduler for this xe_exec_queue */
 	struct xe_gpu_scheduler sched;
 	/** @entity: Scheduler entity for this xe_exec_queue */
diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
index df7a5a4eec74..7170e78e5b8e 100644
--- a/drivers/gpu/drm/xe/xe_guc_submit.c
+++ b/drivers/gpu/drm/xe/xe_guc_submit.c
@@ -1299,11 +1299,7 @@ static void __guc_exec_queue_fini_async(struct work_struct *w)
 	xe_sched_entity_fini(&ge->entity);
 	xe_sched_fini(&ge->sched);
 
-	/*
-	 * RCU free due sched being exported via DRM scheduler fences
-	 * (timeline name).
-	 */
-	kfree_rcu(ge, rcu);
+	kfree(ge);
 	xe_exec_queue_fini(q);
 	xe_pm_runtime_put(guc_to_xe(guc));
 }
@@ -1486,7 +1482,6 @@ static int guc_exec_queue_init(struct xe_exec_queue *q)
 
 	q->guc = ge;
 	ge->q = q;
-	init_rcu_head(&ge->rcu);
 	init_waitqueue_head(&ge->suspend_wait);
 
 	for (i = 0; i < MAX_STATIC_MSG_TYPE; ++i)
-- 
2.34.1