From b44135351a3a5cfc60f5b6729445311c2d5e141c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christian=20K=C3=B6nig?= Date: Tue, 15 Mar 2016 13:40:17 +0100 Subject: [PATCH] drm/amdgpu: RCU protected amdgpu_fence_release MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fences must be freed RCU protected, otherwise the reservation_object_*_rcu() functions can run into problems. Signed-off-by: Christian König Reviewed-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index d8bbe85c22a2..ec73ab1c177d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -638,12 +638,33 @@ static bool amdgpu_fence_enable_signaling(struct fence *f) 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,