efi: Export more EFI table variables to sysfs
Export fw_vendor, runtime and config table physical addresses to
/sys/firmware/efi/{fw_vendor,runtime,config_table} because kexec kernels
need them.
From EFI spec these 3 variables will be updated to virtual address after
entering virtual mode. But kernel startup code will need the physical
address.
Signed-off-by: Dave Young <dyoung@redhat.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 2e2fbde..72533af 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -32,6 +32,9 @@
.hcdp = EFI_INVALID_TABLE_ADDR,
.uga = EFI_INVALID_TABLE_ADDR,
.uv_systab = EFI_INVALID_TABLE_ADDR,
+ .fw_vendor = EFI_INVALID_TABLE_ADDR,
+ .runtime = EFI_INVALID_TABLE_ADDR,
+ .config_table = EFI_INVALID_TABLE_ADDR,
};
EXPORT_SYMBOL(efi);
@@ -71,13 +74,49 @@
static struct kobj_attribute efi_attr_systab =
__ATTR(systab, 0400, systab_show, NULL);
+#define EFI_FIELD(var) efi.var
+
+#define EFI_ATTR_SHOW(name) \
+static ssize_t name##_show(struct kobject *kobj, \
+ struct kobj_attribute *attr, char *buf) \
+{ \
+ return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
+}
+
+EFI_ATTR_SHOW(fw_vendor);
+EFI_ATTR_SHOW(runtime);
+EFI_ATTR_SHOW(config_table);
+
+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 attribute *efi_subsys_attrs[] = {
&efi_attr_systab.attr,
- NULL, /* maybe more in the future? */
+ &efi_attr_fw_vendor.attr,
+ &efi_attr_runtime.attr,
+ &efi_attr_config_table.attr,
+ NULL,
};
+static umode_t efi_attr_is_visible(struct kobject *kobj,
+ struct attribute *attr, int n)
+{
+ umode_t mode = attr->mode;
+
+ if (attr == &efi_attr_fw_vendor.attr)
+ return (efi.fw_vendor == EFI_INVALID_TABLE_ADDR) ? 0 : mode;
+ else if (attr == &efi_attr_runtime.attr)
+ return (efi.runtime == EFI_INVALID_TABLE_ADDR) ? 0 : mode;
+ else if (attr == &efi_attr_config_table.attr)
+ return (efi.config_table == EFI_INVALID_TABLE_ADDR) ? 0 : mode;
+
+ return mode;
+}
+
static struct attribute_group efi_subsys_attr_group = {
.attrs = efi_subsys_attrs,
+ .is_visible = efi_attr_is_visible,
};
static struct efivars generic_efivars;