[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / firmware / efi / efi.c

/*
 * efi.c - EFI subsystem
 *
 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
 * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
 *
 * 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>

static struct kobject *efi_kobj;
static struct kobject *efivars_kobj;

/*
 * Let's not leave out systab information that snuck into
 * the efivars driver
 */
static ssize_t systab_show(struct kobject *kobj,
			   struct kobj_attribute *attr, char *buf)
{
	char *str = buf;

	if (!kobj || !buf)
		return -EINVAL;

	if (efi.mps != EFI_INVALID_TABLE_ADDR)
		str += sprintf(str, "MPS=0x%lx\n", efi.mps);
	if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
		str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
	if (efi.acpi != EFI_INVALID_TABLE_ADDR)
		str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
	if (efi.smbios != EFI_INVALID_TABLE_ADDR)
		str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
	if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
		str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
	if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
		str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
	if (efi.uga != EFI_INVALID_TABLE_ADDR)
		str += sprintf(str, "UGA=0x%lx\n", efi.uga);

	return str - buf;
}

static struct kobj_attribute efi_attr_systab =
			__ATTR(systab, 0400, systab_show, NULL);

static struct attribute *efi_subsys_attrs[] = {
	&efi_attr_systab.attr,
	NULL,	/* maybe more in the future? */
};

static struct attribute_group efi_subsys_attr_group = {
	.attrs = efi_subsys_attrs,
};

static struct efivars generic_efivars;
static struct efivar_operations generic_ops;

static int generic_ops_register(void)
{
	generic_ops.get_variable = efi.get_variable;
	generic_ops.set_variable = efi.set_variable;
	generic_ops.get_next_variable = efi.get_next_variable;
	generic_ops.query_variable_store = efi_query_variable_store;

	return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
}

static void generic_ops_unregister(void)
{
	efivars_unregister(&generic_efivars);
}

/*
 * We register the efi subsystem with the firmware subsystem and the
 * efivars subsystem with the efi subsystem, if the system was booted with
 * EFI.
 */
static int __init efisubsys_init(void)
{
	int error;

	if (!efi_enabled(EFI_BOOT))
		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("efi: Firmware registration failed.\n");
		return -ENOMEM;
	}

	error = generic_ops_register();
	if (error)
		goto err_put;

	error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
	if (error) {
		pr_err("efi: Sysfs attribute export failed with error %d.\n",
		       error);
		goto err_unregister;
	}

	/* and the standard mountpoint for efivarfs */
	efivars_kobj = kobject_create_and_add("efivars", efi_kobj);
	if (!efivars_kobj) {
		pr_err("efivars: Subsystem registration failed.\n");
		error = -ENOMEM;
		goto err_remove_group;
	}

	return 0;

err_remove_group:
	sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
err_unregister:
	generic_ops_unregister();
err_put:
	kobject_put(efi_kobj);
	return error;
}

subsys_initcall(efisubsys_init);
Commit	Line	Data
a9499fa7 TG	1	/*
	2	* efi.c - EFI subsystem
	3	*
	4	* Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
	5	* Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
	6	* Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
	7	*
	8	* This code registers /sys/firmware/efi{,/efivars} when EFI is supported,
	9	* allowing the efivarfs to be mounted or the efivars module to be loaded.
	10	* The existance of /sys/firmware/efi may also be used by userspace to
	11	* determine that the system supports EFI.
	12	*
	13	* This file is released under the GPLv2.
	14	*/
	15
	16	#include <linux/kobject.h>
	17	#include <linux/module.h>
	18	#include <linux/init.h>
	19	#include <linux/device.h>
	20	#include <linux/efi.h>
	21
	22	static struct kobject *efi_kobj;
	23	static struct kobject *efivars_kobj;
	24
	25	/*
	26	* Let's not leave out systab information that snuck into
	27	* the efivars driver
	28	*/
	29	static ssize_t systab_show(struct kobject *kobj,
	30	struct kobj_attribute attr, char buf)
	31	{
	32	char *str = buf;
	33
	34	if (!kobj \|\| !buf)
	35	return -EINVAL;
	36
	37	if (efi.mps != EFI_INVALID_TABLE_ADDR)
	38	str += sprintf(str, "MPS=0x%lx\n", efi.mps);
	39	if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
	40	str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
	41	if (efi.acpi != EFI_INVALID_TABLE_ADDR)
	42	str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
	43	if (efi.smbios != EFI_INVALID_TABLE_ADDR)
	44	str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
	45	if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
	46	str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
	47	if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
	48	str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
	49	if (efi.uga != EFI_INVALID_TABLE_ADDR)
	50	str += sprintf(str, "UGA=0x%lx\n", efi.uga);
	51
	52	return str - buf;
	53	}
	54
	55	static struct kobj_attribute efi_attr_systab =
	56	__ATTR(systab, 0400, systab_show, NULL);
	57
	58	static struct attribute *efi_subsys_attrs[] = {
	59	&efi_attr_systab.attr,
	60	NULL, /* maybe more in the future? */
	61	};
	62
	63	static struct attribute_group efi_subsys_attr_group = {
	64	.attrs = efi_subsys_attrs,
65	};
66
67	static struct efivars generic_efivars;
68	static struct efivar_operations generic_ops;
69
70	static int generic_ops_register(void)
71	{
72	generic_ops.get_variable = efi.get_variable;
73	generic_ops.set_variable = efi.set_variable;
74	generic_ops.get_next_variable = efi.get_next_variable;
a614e192	75	generic_ops.query_variable_store = efi_query_variable_store;
a9499fa7 TG	76
	77	return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
	78	}
	79
	80	static void generic_ops_unregister(void)
	81	{
	82	efivars_unregister(&generic_efivars);
	83	}
	84
	85	/*
	86	* We register the efi subsystem with the firmware subsystem and the
	87	* efivars subsystem with the efi subsystem, if the system was booted with
	88	* EFI.
	89	*/
	90	static int __init efisubsys_init(void)
	91	{
	92	int error;
	93
	94	if (!efi_enabled(EFI_BOOT))
	95	return 0;
	96
	97	/* We register the efi directory at /sys/firmware/efi */
	98	efi_kobj = kobject_create_and_add("efi", firmware_kobj);
	99	if (!efi_kobj) {
	100	pr_err("efi: Firmware registration failed.\n");
	101	return -ENOMEM;
	102	}
	103
	104	error = generic_ops_register();
	105	if (error)
	106	goto err_put;
	107
	108	error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
	109	if (error) {
	110	pr_err("efi: Sysfs attribute export failed with error %d.\n",
	111	error);
	112	goto err_unregister;
	113	}
	114
	115	/* and the standard mountpoint for efivarfs */
	116	efivars_kobj = kobject_create_and_add("efivars", efi_kobj);
	117	if (!efivars_kobj) {
	118	pr_err("efivars: Subsystem registration failed.\n");
	119	error = -ENOMEM;
	120	goto err_remove_group;
	121	}
	122
	123	return 0;
	124
	125	err_remove_group:
	126	sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
	127	err_unregister:
	128	generic_ops_unregister();
	129	err_put:
	130	kobject_put(efi_kobj);
	131	return error;
	132	}
	133
	134	subsys_initcall(efisubsys_init);