drm/amdgpu: RCU protected amdgpu_fence_release
Fences must be freed RCU protected, otherwise the reservation_object_*_rcu()
functions can run into problems.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
index d8bbe85..ec73ab1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
@@ -638,12 +638,33 @@
return true;
}
-static void amdgpu_fence_release(struct fence *f)
+/**
+ * amdgpu_fence_free - free up the fence memory
+ *
+ * @rcu: RCU callback head
+ *
+ * Free up the fence memory after the RCU grace period.
+ */
+static void amdgpu_fence_free(struct rcu_head *rcu)
{
+ struct fence *f = container_of(rcu, struct fence, rcu);
struct amdgpu_fence *fence = to_amdgpu_fence(f);
kmem_cache_free(amdgpu_fence_slab, fence);
}
+/**
+ * amdgpu_fence_release - callback that fence can be freed
+ *
+ * @fence: fence
+ *
+ * This function is called when the reference count becomes zero.
+ * It just RCU schedules freeing up the fence.
+ */
+static void amdgpu_fence_release(struct fence *f)
+{
+ call_rcu(&f->rcu, amdgpu_fence_free);
+}
+
static const struct fence_ops amdgpu_fence_ops = {
.get_driver_name = amdgpu_fence_get_driver_name,
.get_timeline_name = amdgpu_fence_get_timeline_name,