[PATCH AUTOSEL 4.19 005/177] drm/amdgpu: grab the id mgr lock while accessing passid_mapping

Sasha Levin
2019-12-10T21:47:17Z

From: Christian König <christian.koenig@amd.com>

[ Upstream commit 6817bf283b2b851095825ec7f0e9f10398e09125 ]

Need to make sure that we actually dropping the right fence.
Could be done with RCU as well, but to complicated for a fix.

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>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 49fe5084c53dd..69fb90d9c4855 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -700,10 +700,8 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job, bool need_
id->oa_base != job->oa_base ||
id->oa_size != job->oa_size);
bool vm_flush_needed = job->vm_needs_flush;
- bool pasid_mapping_needed = id->pasid != job->pasid ||
- !id->pasid_mapping ||
- !dma_fence_is_signaled(id->pasid_mapping);
struct dma_fence *fence = NULL;
+ bool pasid_mapping_needed;
unsigned patch_offset = 0;
int r;

@@ -713,6 +711,12 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job, bool need_
pasid_mapping_needed = true;
}

+ mutex_lock(&id_mgr->lock);
+ if (id->pasid != job->pasid || !id->pasid_mapping ||
+ !dma_fence_is_signaled(id->pasid_mapping))
+ pasid_mapping_needed = true;
+ mutex_unlock(&id_mgr->lock);
+
gds_switch_needed &= !!ring->funcs->emit_gds_switch;
vm_flush_needed &= !!ring->funcs->emit_vm_flush &&
job->vm_pd_addr != AMDGPU_BO_INVALID_OFFSET;
@@ -752,9 +756,11 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job, bool need_
}

if (pasid_mapping_needed) {
+ mutex_lock(&id_mgr->lock);
id->pasid = job->pasid;
dma_fence_put(id->pasid_mapping);
id->pasid_mapping = dma_fence_get(fence);
+ mutex_unlock(&id_mgr->lock);
}
dma_fence_put(fence);

--
2.20.1