This registers /sys/firmware/efi{,/efivars} whenever EFI is enabled
and the system supports it.
This allows
*) userspace to check for the existence of /sys/firmware/efi as a way
to determine whether or it is running on an EFI system.
*) 'mount -t efivarfs none /sys/firmware/efi/efivars' without manually
loading any modules.
Signed-off-by: Tom Gundersen <[email protected]>
Cc: Matt Fleming <[email protected]>
Cc: Kay Sievers <[email protected]>
Cc: Jeremy Kerr <[email protected]>
Cc: Matthew Garrett <[email protected]>
Cc: Chun-Yi Lee <[email protected]>
Cc: Andy Whitcroft <[email protected]>
---
drivers/firmware/Makefile | 1 +
drivers/firmware/efisubsys.c | 52 ++++++++++++++++++++++++++++++++++++++++++++
drivers/firmware/efivars.c | 30 +++++--------------------
3 files changed, 59 insertions(+), 24 deletions(-)
create mode 100644 drivers/firmware/efisubsys.c
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 5a7e273..e89c5da 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -4,6 +4,7 @@
obj-$(CONFIG_DMI) += dmi_scan.o
obj-$(CONFIG_DMI_SYSFS) += dmi-sysfs.o
obj-$(CONFIG_EDD) += edd.o
+obj-$(CONFIG_EFI) += efisubsys.o
obj-$(CONFIG_EFI_VARS) += efivars.o
obj-$(CONFIG_EFI_PCDP) += pcdp.o
obj-$(CONFIG_DELL_RBU) += dell_rbu.o
diff --git a/drivers/firmware/efisubsys.c b/drivers/firmware/efisubsys.c
new file mode 100644
index 0000000..e09c333
--- /dev/null
+++ b/drivers/firmware/efisubsys.c
@@ -0,0 +1,52 @@
+/*
+ * efi.c - EFI subsystem
+ *
+ * Copyright (C) 2013 Tom Gundersen <[email protected]>
+ *
+ * This code registers /sys/firmware/efi{,/efivars} when EFI is supported,
+ * allowing the efivarfs to be mounted or the efivars module to be loaded.
+ * The existance of /sys/firmware/efi may also be used by userspace to
+ * determine that the system supports EFI.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/efi.h>
+
+struct kobject *efi_kobj;
+EXPORT_SYMBOL_GPL(efi_kobj);
+struct kobject *efivars_kobj;
+EXPORT_SYMBOL_GPL(efivars_kobj);
+
+/*
+ * We register the efi subsystem with the firmware subsystem and the
+ * efivars subsystem with the efi subsystem.
+ */
+static int __init efisubsys_init(void)
+{
+ if (!efi_enabled)
+ return 0;
+
+ /* We register the efi directory at /sys/firmware/efi */
+ efi_kobj = kobject_create_and_add("efi", firmware_kobj);
+ if (!efi_kobj) {
+ pr_err("efivars: Firmware registration failed.\n");
+ return -ENOMEM;
+ }
+
+ /* and the mountpoint for efivarfs at /sys/firmware/efi/efivars */
+ efivars_kobj = kobject_create_and_add("efivars", efi_kobj);
+ if (!efivars_kobj) {
+ pr_err("efivars: Subsystem registration failed.\n");
+ kobject_put(efi_kobj);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+subsys_initcall(efisubsys_init);
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index b7cff5c..9a929d4 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -1528,7 +1528,8 @@ static struct attribute_group efi_subsys_attr_group = {
.attrs = efi_subsys_attrs,
};
-static struct kobject *efi_kobj;
+extern struct kobject *efi_kobj;
+extern struct kobject *efivars_kobj;
/*
* efivar_create_sysfs_entry()
@@ -1708,13 +1709,7 @@ int register_efivars(struct efivars *efivars,
goto out;
}
- efivars->kobject = kobject_create_and_add("efivars", parent_kobj);
- if (!efivars->kobject) {
- pr_err("efivars: Subsystem registration failed.\n");
- error = -ENOMEM;
- kset_unregister(efivars->kset);
- goto out;
- }
+ efivars->kobject = efivars_kobj;
/*
* Per EFI spec, the maximum storage allocated for both
@@ -1768,11 +1763,7 @@ out:
EXPORT_SYMBOL_GPL(register_efivars);
/*
- * For now we register the efi subsystem with the firmware subsystem
- * and the vars subsystem with the efi subsystem. In the future, it
- * might make sense to split off the efi subsystem into its own
- * driver, but for now only efivars will register with it, so just
- * include it here.
+ * We register the vars subsystem with the efi subsystem.
*/
static int __init
@@ -1786,21 +1777,15 @@ efivars_init(void)
if (!efi_enabled)
return 0;
- /* For now we'll register the efi directory at /sys/firmware/efi */
- efi_kobj = kobject_create_and_add("efi", firmware_kobj);
- if (!efi_kobj) {
- printk(KERN_ERR "efivars: Firmware registration failed.\n");
- return -ENOMEM;
- }
-
ops.get_variable = efi.get_variable;
ops.set_variable = efi.set_variable;
ops.get_next_variable = efi.get_next_variable;
ops.query_variable_info = efi.query_variable_info;
error = register_efivars(&__efivars, &ops, efi_kobj);
+
if (error)
- goto err_put;
+ goto err_unregister;
/* Don't forget the systab entry */
error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
@@ -1815,8 +1800,6 @@ efivars_init(void)
err_unregister:
unregister_efivars(&__efivars);
-err_put:
- kobject_put(efi_kobj);
return error;
}
@@ -1825,7 +1808,6 @@ efivars_exit(void)
{
if (efi_enabled) {
unregister_efivars(&__efivars);
- kobject_put(efi_kobj);
}
}
--
1.8.1.1
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