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authorChristian König2019-03-29 19:30:23 +0100
committerGreg Kroah-Hartman2019-05-31 15:46:23 +0200
commitd8a36f8418034bacef0b5b73c0822f41646d77ba (patch)
tree0418c22d4884e4285f0406e3aee6ed9a4c539ce6 /drivers/gpu/drm/amd
parentmmc: sdhci-of-esdhc: add erratum eSDHC-A001 and A-008358 support (diff)
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drm/amdgpu: fix old fence check in amdgpu_fence_emit
[ Upstream commit 3d2aca8c8620346abdba96c6300d2c0b90a1d0cc ] We don't hold a reference to the old fence, so it can go away any time we are waiting for it to signal. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Chunming Zhou <david1.zhou@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/gpu/drm/amd')
-rw-r--r--drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c24
1 files changed, 17 insertions, 7 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
index 7056925eb386..869ff624b108 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
@@ -136,8 +136,9 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f,
{
struct amdgpu_device *adev = ring->adev;
struct amdgpu_fence *fence;
- struct dma_fence *old, **ptr;
+ struct dma_fence __rcu **ptr;
uint32_t seq;
+ int r;
fence = kmem_cache_alloc(amdgpu_fence_slab, GFP_KERNEL);
if (fence == NULL)
@@ -153,15 +154,24 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f,
seq, flags | AMDGPU_FENCE_FLAG_INT);
ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask];
+ if (unlikely(rcu_dereference_protected(*ptr, 1))) {
+ struct dma_fence *old;
+
+ rcu_read_lock();
+ old = dma_fence_get_rcu_safe(ptr);
+ rcu_read_unlock();
+
+ if (old) {
+ r = dma_fence_wait(old, false);
+ dma_fence_put(old);
+ if (r)
+ return r;
+ }
+ }
+
/* This function can't be called concurrently anyway, otherwise
* emitting the fence would mess up the hardware ring buffer.
*/
- old = rcu_dereference_protected(*ptr, 1);
- if (old && !dma_fence_is_signaled(old)) {
- DRM_INFO("rcu slot is busy\n");
- dma_fence_wait(old, false);
- }
-
rcu_assign_pointer(*ptr, dma_fence_get(&fence->base));
*f = &fence->base;