diff options
| author | Christian König <christian.koenig@amd.com> | 2019-03-29 21:30:23 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-31 16:47:28 +0300 |
| commit | c8bd0da237e20664fe481af8aebc9c7c5d6a9e8b (patch) | |
| tree | 4f1efefa3e3750c96c723571a92ba27cb55d7d1d | |
| parent | 1b3f785bdf55bf6f5ca48628b4e1c6ac5f02da64 (diff) | |
| download | linux-c8bd0da237e20664fe481af8aebc9c7c5d6a9e8b.tar.xz | |
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>
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 24 |
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 333bad749067..415e9a384799 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -135,8 +135,9 @@ 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) @@ -152,15 +153,24 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f) seq, 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; |