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authorSteve McIntyre <steve@einval.com>2015-01-09 16:29:53 +0100
committerMatt Fleming <matt.fleming@intel.com>2015-01-12 12:51:32 +0100
commit2859dff97e54db4795b8b7d9606cb8efcec722ff (patch)
tree91836ca6535a94c9fe92972d9c01911f5e0d79ba /drivers/firmware
parentMerge tag 'rneri-efi-next' of https://github.com/ricardon/efi into next (diff)
downloadlinux-2859dff97e54db4795b8b7d9606cb8efcec722ff.tar.xz
linux-2859dff97e54db4795b8b7d9606cb8efcec722ff.zip
efi: Expose underlying UEFI firmware platform size to userland
In some cases (e.g. Intel Bay Trail machines), the kernel will happily run in 64-bit even if the underlying UEFI firmware platform is 32-bit. That's great, but it's difficult for userland utilities like grub-install to do the right thing in such a situation. The kernel already knows about the size of the firmware via efi_enabled(EFI_64BIT). Add an extra sysfs interface /sys/firmware/efi/fw_platform_size to expose that information to userland for low-level utilities to use. Signed-off-by: Steve McIntyre <steve@einval.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efi/efi.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index ff0bbe383b31..9bdbc0533627 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -112,15 +112,24 @@ EFI_ATTR_SHOW(fw_vendor);
EFI_ATTR_SHOW(runtime);
EFI_ATTR_SHOW(config_table);
+static ssize_t fw_platform_size_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
+}
+
static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
+static struct kobj_attribute efi_attr_fw_platform_size =
+ __ATTR_RO(fw_platform_size);
static struct attribute *efi_subsys_attrs[] = {
&efi_attr_systab.attr,
&efi_attr_fw_vendor.attr,
&efi_attr_runtime.attr,
&efi_attr_config_table.attr,
+ &efi_attr_fw_platform_size.attr,
NULL,
};