drm/amdgpu/cgs: add sys info query for pcie gen and link width

BugLink: http://bugs.launchpad.net/bugs/1546572

Needed by powerplay to properly handle pcie dpm switching.
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit cfd316d5)
Signed-off-by: Alberto Milone <alberto.milone@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

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

@@ -754,6 +754,12 @@ static int amdgpu_cgs_query_system_info(void *cgs_device,
 	case CGS_SYSTEM_INFO_ADAPTER_BDF_ID:
 		sys_info->value = adev->pdev->devfn | (adev->pdev->bus->number << 8);
 		break;
+	case CGS_SYSTEM_INFO_PCIE_GEN_INFO:
+		sys_info->value = adev->pm.pcie_gen_mask;
+		break;
+	case CGS_SYSTEM_INFO_PCIE_MLW:
+		sys_info->value = adev->pm.pcie_mlw_mask;
+		break;
 	default:
 		return -ENODEV;
 	}

drivers/gpu/drm/amd/include/cgs_common.h

@@ -107,6 +107,8 @@ enum cgs_ucode_id {
 
 enum cgs_system_info_id {
 	CGS_SYSTEM_INFO_ADAPTER_BDF_ID = 1,
+	CGS_SYSTEM_INFO_PCIE_GEN_INFO,
+	CGS_SYSTEM_INFO_PCIE_MLW,
 	CGS_SYSTEM_INFO_ID_MAXIMUM,
 };