[PATCH v2] x86/efi: autoload efivars
From: Lee, Chun-Yi <hidden>
Date: 2014-07-09 10:39:29
Subsystem:
extensible firmware interface (efi), the rest · Maintainers:
Ard Biesheuvel, Linus Torvalds
The original patch is from Ben Hutchings's contribution to debian kernel. Got Ben's permission to remove the code of efi-pstore.c and send to linux-efi: https://github.com/BlankOn/linux-debian/blob/master/debian/patches/features/all/efi-autoload-efivars.patch efivars is generally useful to have on EFI systems, and in some cases it may be impossible to load it after a kernel upgrade in order to complete a boot loader update. At the same time we don't want to waste memory on non-EFI systems by making them built-in. Instead, give them module aliases as if they are platform drivers, and register a corresponding platform device whenever EFI runtime services are available. This should trigger udev to load them. v2: Moving platform device register code to drivers/firmware/efi/efi.c ARM64 folks could also benefit from it. Cc: Ben Hutchings <ben-/+tVBieCtBitmTQ+vhA3Yw@public.gmane.org> Cc: Matt Fleming <redacted> Signed-off-by: Lee, Chun-Yi <jlee-IBi9RG/b67k@public.gmane.org> --- drivers/firmware/efi/efi.c | 15 +++++++++++++++ drivers/firmware/efi/efivars.c | 1 + 2 files changed, 16 insertions(+)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index eff1a2f..6fee86b 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c@@ -23,6 +23,7 @@ #include <linux/of.h> #include <linux/of_fdt.h> #include <linux/io.h> +#include <linux/platform_device.h> struct efi __read_mostly efi = { .mps = EFI_INVALID_TABLE_ADDR,
@@ -321,6 +322,20 @@ int __init efi_config_init(efi_config_table_type_t *arch_tables) return 0; } +#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 IS_ERR(pdev) ? PTR_ERR(pdev) : 0; +} +device_initcall(efi_load_efivars); +#endif + #ifdef CONFIG_EFI_PARAMS_FROM_FDT #define UEFI_PARAM(name, prop, field) \
diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index 463c565..f256ecd 100644
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c@@ -78,6 +78,7 @@ MODULE_AUTHOR("Matt Domsch <Matt_Domsch-DYMqY+WieiM@public.gmane.org>"); MODULE_DESCRIPTION("sysfs interface to EFI Variables"); MODULE_LICENSE("GPL"); MODULE_VERSION(EFIVARS_VERSION); +MODULE_ALIAS("platform:efivars"); LIST_HEAD(efivar_sysfs_list); EXPORT_SYMBOL_GPL(efivar_sysfs_list);
--
1.8.4.5