efi: Use more granular check for availability for variable services
The UEFI spec rev 2.8 permits firmware implementations to support only
a subset of EFI runtime services at OS runtime (i.e., after the call to
ExitBootServices()), so let's take this into account in the drivers that
rely specifically on the availability of the EFI variable services.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index a352305..abf4c02 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -328,12 +328,13 @@ static int __init efisubsys_init(void)
return -ENOMEM;
}
- error = generic_ops_register();
- if (error)
- goto err_put;
-
- if (efi_enabled(EFI_RUNTIME_SERVICES))
+ if (efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES)) {
efivar_ssdt_load();
+ error = generic_ops_register();
+ if (error)
+ goto err_put;
+ platform_device_register_simple("efivars", 0, NULL, 0);
+ }
error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
if (error) {
@@ -358,7 +359,8 @@ static int __init efisubsys_init(void)
err_remove_group:
sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
err_unregister:
- generic_ops_unregister();
+ if (efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES))
+ generic_ops_unregister();
err_put:
kobject_put(efi_kobj);
return error;
@@ -650,20 +652,6 @@ void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
vendor);
}
-#ifdef CONFIG_EFI_VARS_MODULE
-static int __init efi_load_efivars(void)
-{
- struct platform_device *pdev;
-
- if (!efi_enabled(EFI_RUNTIME_SERVICES))
- return 0;
-
- pdev = platform_device_register_simple("efivars", 0, NULL, 0);
- return PTR_ERR_OR_ZERO(pdev);
-}
-device_initcall(efi_load_efivars);
-#endif
-
static __initdata char memory_type_name[][20] = {
"Reserved",
"Loader Code",