drm/amdgpu: add generic pci reset as an option

This allows us to use generic PCI reset mechanisms (FLR, SBR) as
a reset mechanism to verify that the generic PCI reset mechanisms
are working properly.
Acked-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu.h

@@ -579,7 +579,8 @@ enum amd_reset_method {
 	AMD_RESET_METHOD_MODE0,
 	AMD_RESET_METHOD_MODE1,
 	AMD_RESET_METHOD_MODE2,
-	AMD_RESET_METHOD_BACO
+	AMD_RESET_METHOD_BACO,
+	AMD_RESET_METHOD_PCI,
 };
 
 /*
@@ -1228,6 +1229,7 @@ bool amdgpu_device_should_recover_gpu(struct amdgpu_device *adev);
 int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
 			      struct amdgpu_job* job);
 void amdgpu_device_pci_config_reset(struct amdgpu_device *adev);
+int amdgpu_device_pci_reset(struct amdgpu_device *adev);
 bool amdgpu_device_need_post(struct amdgpu_device *adev);
 
 void amdgpu_cs_report_moved_bytes(struct amdgpu_device *adev, u64 num_bytes,

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -929,6 +929,18 @@ void amdgpu_device_pci_config_reset(struct amdgpu_device *adev)
 	pci_write_config_dword(adev->pdev, 0x7c, AMDGPU_ASIC_RESET_DATA);
 }
 
+/**
+ * amdgpu_device_pci_reset - reset the GPU using generic PCI means
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Resets the GPU using generic pci reset interfaces (FLR, SBR, etc.).
+ */
+int amdgpu_device_pci_reset(struct amdgpu_device *adev)
+{
+	return pci_reset_function(adev->pdev);
+}
+
 /*
  * GPU doorbell aperture helpers function.
  */

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -793,9 +793,9 @@ module_param_named(tmz, amdgpu_tmz, int, 0444);
 
 /**
  * DOC: reset_method (int)
- * GPU reset method (-1 = auto (default), 0 = legacy, 1 = mode0, 2 = mode1, 3 = mode2, 4 = baco)
+ * GPU reset method (-1 = auto (default), 0 = legacy, 1 = mode0, 2 = mode1, 3 = mode2, 4 = baco, 5 = pci)
  */
-MODULE_PARM_DESC(reset_method, "GPU reset method (-1 = auto (default), 0 = legacy, 1 = mode0, 2 = mode1, 3 = mode2, 4 = baco/bamaco)");
+MODULE_PARM_DESC(reset_method, "GPU reset method (-1 = auto (default), 0 = legacy, 1 = mode0, 2 = mode1, 3 = mode2, 4 = baco/bamaco, 5 = pci)");
 module_param_named(reset_method, amdgpu_reset_method, int, 0444);
 
 /**