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authorChristian König <christian.koenig@amd.com>2022-11-02 14:55:13 +0100
committerAlex Deucher <alexander.deucher@amd.com>2022-11-09 17:58:17 -0500
commit77c092e054262b594614bad5e5f47e57c5d29639 (patch)
tree16371094df3c5af8285e0fcf3f67f5b8232d47d7 /drivers
parentdrm/amdkfd: Fix error handling in criu_checkpoint (diff)
downloadlinux-dev-77c092e054262b594614bad5e5f47e57c5d29639.tar.xz
linux-dev-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')
-rw-r--r--drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h15
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);
}