efi: expose efivar generic ops register function

This is a preparation for supporting efivar operations provided by other
than efi subsystem.  Both register and unregister functions are exposed
so that non-efi subsystem can revert the efi generic operation.
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Co-developed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

drivers/firmware/efi/efi.c

@@ -231,6 +231,18 @@ static void generic_ops_unregister(void)
 	efivars_unregister(&generic_efivars);
 }
 
+void efivars_generic_ops_register(void)
+{
+	generic_ops_register();
+}
+EXPORT_SYMBOL_GPL(efivars_generic_ops_register);
+
+void efivars_generic_ops_unregister(void)
+{
+	generic_ops_unregister();
+}
+EXPORT_SYMBOL_GPL(efivars_generic_ops_unregister);
+
 #ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS
 #define EFIVAR_SSDT_NAME_MAX	16UL
 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;

include/linux/efi.h

@@ -1348,4 +1348,7 @@ bool efi_config_table_is_usable(const efi_guid_t *guid, unsigned long table)
 
 umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n);
 
+void efivars_generic_ops_register(void);
+void efivars_generic_ops_unregister(void);
+
 #endif /* _LINUX_EFI_H */