From 871a45729603c20acb9a0927eb549b667c9b68ba Mon Sep 17 00:00:00 2001 From: Alex Sierra Date: Mon, 18 Nov 2019 15:33:07 -0600 Subject: [PATCH 4554/4736] amd/amdgpu: force to trigger a no-retry-fault after a retry-fault MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Only for the debugger use case. [why] Avoid endless translation retries, after an invalid address access has been issued to the GPU. Instead, the trap handler is forced to enter by generating a no-retry-fault. A s_trap instruction is inserted in the debugger case to let the wave to enter trap handler to save context. [how] Intentionally using an invalid flag combination (F and P set at the same time) to trigger a no-retry-fault, after a retry-fault happens. This is only valid under compute context. Change-Id: I4180c30e2631dc0401cbd6171f8a6776e4733c9a Signed-off-by: Alex Sierra Reviewed-by: Felix Kuehling Reviewed-by: Christian König --- drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c index c3e87ca13c53..90ac5390ecdf 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c @@ -3204,11 +3204,20 @@ bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, unsigned int pasid, flags = AMDGPU_PTE_VALID | AMDGPU_PTE_SNOOPED | AMDGPU_PTE_SYSTEM; - if (amdgpu_vm_fault_stop == AMDGPU_VM_FAULT_STOP_NEVER) { + if (vm->is_compute_context) { + /* Intentionally setting invalid PTE flag + * combination to force a no-retry-fault + */ + flags = AMDGPU_PTE_EXECUTABLE | AMDGPU_PDE_PTE | + AMDGPU_PTE_TF; + value = 0; + + } else if (amdgpu_vm_fault_stop == AMDGPU_VM_FAULT_STOP_NEVER) { /* Redirect the access to the dummy page */ value = adev->dummy_page_addr; flags |= AMDGPU_PTE_EXECUTABLE | AMDGPU_PTE_READABLE | AMDGPU_PTE_WRITEABLE; + } else { /* Let the hw retry silently on the PTE */ value = 0; -- 2.17.1