[PATCH v3] amd/amdgpu: Fix resv shared fence overflow

[xinhui pan]

[  179.556745] kernel BUG at drivers/dma-buf/dma-resv.c:282!
[snip]
[  179.702910] Call Trace:
[  179.705696]  amdgpu_bo_fence+0x21/0x50 [amdgpu]
[  179.710707]  amdgpu_vm_sdma_commit+0x299/0x430 [amdgpu]
[  179.716497]  amdgpu_vm_bo_update_mapping.constprop.0+0x29f/0x390 [amdgpu]
[  179.723927]  ? find_held_lock+0x38/0x90
[  179.728183]  amdgpu_vm_handle_fault+0x1af/0x420 [amdgpu]
[  179.734063]  gmc_v9_0_process_interrupt+0x245/0x2e0 [amdgpu]
[  179.740347]  ? kgd2kfd_interrupt+0xb8/0x1e0 [amdgpu]
[  179.745808]  amdgpu_irq_dispatch+0x10a/0x3c0 [amdgpu]
[  179.751380]  ? amdgpu_irq_dispatch+0x10a/0x3c0 [amdgpu]
[  179.757159]  amdgpu_ih_process+0xbb/0x1a0 [amdgpu]
[  179.762466]  amdgpu_irq_handle_ih1+0x27/0x40 [amdgpu]
[  179.767997]  process_one_work+0x23c/0x580
[  179.772371]  worker_thread+0x50/0x3b0
[  179.776356]  ? process_one_work+0x580/0x580
[  179.780939]  kthread+0x128/0x160
[  179.784462]  ? kthread_park+0x90/0x90
[  179.788466]  ret_from_fork+0x1f/0x30

We have two scheduler entities, immediate and delayed.
So there are two kinds of scheduler finished fences.
We might add these two fences in root bo resv at same time.

We have reserved the delayed shared fence slot during vm init and bo
moving.
But looks like we forget to reserve the immediate shared fence slot
during vm fault.

Signed-off-by: xinhui pan <xinhui.pan at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 3cd949aad500..a737232ceb38 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -3352,6 +3352,9 @@ bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, unsigned int pasid,
 	if (!vm)
 		goto error_unlock;
 
+	if (dma_resv_reserve_shared(root->tbo.base.resv, 1))
+		goto error_unlock;
+
 	addr /= AMDGPU_GPU_PAGE_SIZE;
 	flags = AMDGPU_PTE_VALID | AMDGPU_PTE_SNOOPED |
 		AMDGPU_PTE_SYSTEM;
-- 
2.25.1