amdgpu: Don't print L2 status if there's nothing to print

If a 2nd fault comes in before the 1st is handled, the 1st fault will
clear out the FAULT STATUS registers before the 2nd fault is handled.
Thus we get a lot of zeroes. If status=0, just skip the L2 fault status
information, to avoid confusion of why some VM fault status prints in
dmesg are all zeroes.

Signed-off-by: Kent Russell <[e-mail]>
Reviewed-by: Felix Kuehling <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c

···
 			addr, entry->client_id,
 			soc15_ih_clientid_name[entry->client_id]);
 
-	if (!amdgpu_sriov_vf(adev))
+	/* Only print L2 fault status if the status register could be read and
+	 * contains useful information
+	 */
+	if (status != 0)
 		hub->vmhub_funcs->print_l2_protection_fault_status(adev,
 								   status);
 

drivers/gpu/drm/amd/amdgpu/gmc_v11_0.c

···
 		dev_err(adev->dev, "  in page starting at address 0x%016llx from client %d\n",
 				addr, entry->client_id);
 
-		if (!amdgpu_sriov_vf(adev))
+		/* Only print L2 fault status if the status register could be read and
+		 * contains useful information
+		 */
+		if (status != 0)
 			hub->vmhub_funcs->print_l2_protection_fault_status(adev, status);
 	}
 

drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c

···
 		dev_err(adev->dev, "  in page starting at address 0x%016llx from client %d\n",
 				addr, entry->client_id);
 
-		if (!amdgpu_sriov_vf(adev))
+		/* Only print L2 fault status if the status register could be read and
+		 * contains useful information
+		 */
+		if (status != 0)
 			hub->vmhub_funcs->print_l2_protection_fault_status(adev, status);
 	}
 

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

···
 	    (amdgpu_ip_version(adev, GC_HWIP, 0) >= IP_VERSION(9, 4, 2)))
 		return 0;
 
+	/* Only print L2 fault status if the status register could be read and
+	 * contains useful information
+	 */
+	if (!status)
+		return 0;
+
 	if (!amdgpu_sriov_vf(adev))
 		WREG32_P(hub->vm_l2_pro_fault_cntl, 1, ~1);