This allows us to query certain registers from userspace
for profiling and harvest configuration.  E.g., it can
be used by the GALLIUM_HUD for profiling the status of
various gfx blocks.
Tested-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
                else
                        *value = rdev->pm.current_mclk / 100;
                break;
+       case RADEON_INFO_READ_REG:
+               if (copy_from_user(value, value_ptr, sizeof(uint32_t))) {
+                       DRM_ERROR("copy_from_user %s:%u\n", __func__, __LINE__);
+                       return -EFAULT;
+               }
+               if (radeon_get_allowed_info_register(rdev, *value, value))
+                       return -EINVAL;
+               break;
        default:
                DRM_DEBUG_KMS("Invalid request %d\n", info->request);
                return -EINVAL;
 
 #define RADEON_INFO_CURRENT_GPU_TEMP   0x21
 #define RADEON_INFO_CURRENT_GPU_SCLK   0x22
 #define RADEON_INFO_CURRENT_GPU_MCLK   0x23
+#define RADEON_INFO_READ_REG           0x24
 
 struct drm_radeon_info {
        uint32_t                request;