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| author | Christian König <christian.koenig@amd.com> | 2022-11-02 14:55:13 +0100 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2022-11-09 17:58:17 -0500 |
| commit | 77c092e054262b594614bad5e5f47e57c5d29639 (patch) | |
| tree | 16371094df3c5af8285e0fcf3f67f5b8232d47d7 /drivers/gpu | |
| parent | b91c23e099f0b65d62159da13458c5eefa76083f (diff) | |
| download | lwn-77c092e054262b594614bad5e5f47e57c5d29639.tar.gz lwn-77c092e054262b594614bad5e5f47e57c5d29639.zip | |
drm/amdgpu: workaround for TLB seq race
It can happen that we query the sequence value before the callback
had a chance to run.
Workaround that by grabbing the fence lock and releasing it again.
Should be replaced by hw handling soon.
Signed-off-by: Christian König <christian.koenig@amd.com>
CC: stable@vger.kernel.org # 5.19+
Fixes: 5255e146c99a6 ("drm/amdgpu: rework TLB flushing")
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2113
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Philip Yang <Philip.Yang@amd.com>
Tested-by: Stefan Springer <stefanspr94@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h index 83acb7bd80fe..1d31771b4230 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h @@ -492,6 +492,21 @@ void amdgpu_debugfs_vm_bo_info(struct amdgpu_vm *vm, struct seq_file *m); */ static inline uint64_t amdgpu_vm_tlb_seq(struct amdgpu_vm *vm) { + unsigned long flags; + spinlock_t *lock; + + /* + * Workaround to stop racing between the fence signaling and handling + * the cb. The lock is static after initially setting it up, just make + * sure that the dma_fence structure isn't freed up. + */ + rcu_read_lock(); + lock = vm->last_tlb_flush->lock; + rcu_read_unlock(); + + spin_lock_irqsave(lock, flags); + spin_unlock_irqrestore(lock, flags); + return atomic64_read(&vm->tlb_seq); } |