[deliverable/linux.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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/efi.h>
#include <linux/io.h>

struct efi __read_mostly efi = {
	.mps        = EFI_INVALID_TABLE_ADDR,
	.acpi       = EFI_INVALID_TABLE_ADDR,
	.acpi20     = EFI_INVALID_TABLE_ADDR,
	.smbios     = EFI_INVALID_TABLE_ADDR,
	.sal_systab = EFI_INVALID_TABLE_ADDR,
	.boot_info  = EFI_INVALID_TABLE_ADDR,
	.hcdp       = EFI_INVALID_TABLE_ADDR,
	.uga        = EFI_INVALID_TABLE_ADDR,
	.uv_systab  = EFI_INVALID_TABLE_ADDR,
};
EXPORT_SYMBOL(efi);

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);


/*
 * We can't ioremap data in EFI boot services RAM, because we've already mapped
 * it as RAM.  So, look it up in the existing EFI memory map instead.  Only
 * callable after efi_enter_virtual_mode and before efi_free_boot_services.
 */
void __iomem *efi_lookup_mapped_addr(u64 phys_addr)
{
	struct efi_memory_map *map;
	void *p;
	map = efi.memmap;
	if (!map)
		return NULL;
	if (WARN_ON(!map->map))
		return NULL;
	for (p = map->map; p < map->map_end; p += map->desc_size) {
		efi_memory_desc_t *md = p;
		u64 size = md->num_pages << EFI_PAGE_SHIFT;
		u64 end = md->phys_addr + size;
		if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
		    md->type != EFI_BOOT_SERVICES_CODE &&
		    md->type != EFI_BOOT_SERVICES_DATA)
			continue;
		if (!md->virt_addr)
			continue;
		if (phys_addr >= md->phys_addr && phys_addr < end) {
			phys_addr += md->virt_addr - md->phys_addr;
			return (__force void __iomem *)(unsigned long)phys_addr;
		}
	}
	return NULL;
}

static __initdata efi_config_table_type_t common_tables[] = {
	{ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
	{ACPI_TABLE_GUID, "ACPI", &efi.acpi},
	{HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
	{MPS_TABLE_GUID, "MPS", &efi.mps},
	{SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
	{SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
	{UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
	{NULL_GUID, NULL, 0},
};

static __init int match_config_table(efi_guid_t *guid,
				     unsigned long table,
				     efi_config_table_type_t *table_types)
{
	u8 str[EFI_VARIABLE_GUID_LEN + 1];
	int i;

	if (table_types) {
		efi_guid_unparse(guid, str);

		for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
			efi_guid_unparse(&table_types[i].guid, str);

			if (!efi_guidcmp(*guid, table_types[i].guid)) {
				*(table_types[i].ptr) = table;
				pr_cont(" %s=0x%lx ",
					table_types[i].name, table);
				return 1;
			}
		}
	}

	return 0;
}

int __init efi_config_init(efi_config_table_type_t *arch_tables)
{
	void *config_tables, *tablep;
	int i, sz;

	if (efi_enabled(EFI_64BIT))
		sz = sizeof(efi_config_table_64_t);
	else
		sz = sizeof(efi_config_table_32_t);

	/*
	 * Let's see what config tables the firmware passed to us.
	 */
	config_tables = early_memremap(efi.systab->tables,
				       efi.systab->nr_tables * sz);
	if (config_tables == NULL) {
		pr_err("Could not map Configuration table!\n");
		return -ENOMEM;
	}

	tablep = config_tables;
	pr_info("");
	for (i = 0; i < efi.systab->nr_tables; i++) {
		efi_guid_t guid;
		unsigned long table;

		if (efi_enabled(EFI_64BIT)) {
			u64 table64;
			guid = ((efi_config_table_64_t *)tablep)->guid;
			table64 = ((efi_config_table_64_t *)tablep)->table;
			table = table64;
#ifndef CONFIG_64BIT
			if (table64 >> 32) {
				pr_cont("\n");
				pr_err("Table located above 4GB, disabling EFI.\n");
				early_iounmap(config_tables,
					       efi.systab->nr_tables * sz);
				return -EINVAL;
			}
#endif
		} else {
			guid = ((efi_config_table_32_t *)tablep)->guid;
			table = ((efi_config_table_32_t *)tablep)->table;
		}

		if (!match_config_table(&guid, table, common_tables))
			match_config_table(&guid, table, arch_tables);

		tablep += sz;
	}
	pr_cont("\n");
	early_iounmap(config_tables, efi.systab->nr_tables * sz);
	return 0;
}
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
272686bf LL	16	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
272686bf LL	17
a9499fa7 TG	18	#include <linux/kobject.h>
	19	#include <linux/module.h>
	20	#include <linux/init.h>
	21	#include <linux/device.h>
	22	#include <linux/efi.h>
272686bf LL	23	#include <linux/io.h>
	24
	25	struct efi __read_mostly efi = {
	26	.mps = EFI_INVALID_TABLE_ADDR,
	27	.acpi = EFI_INVALID_TABLE_ADDR,
	28	.acpi20 = EFI_INVALID_TABLE_ADDR,
	29	.smbios = EFI_INVALID_TABLE_ADDR,
	30	.sal_systab = EFI_INVALID_TABLE_ADDR,
	31	.boot_info = EFI_INVALID_TABLE_ADDR,
	32	.hcdp = EFI_INVALID_TABLE_ADDR,
	33	.uga = EFI_INVALID_TABLE_ADDR,
	34	.uv_systab = EFI_INVALID_TABLE_ADDR,
	35	};
	36	EXPORT_SYMBOL(efi);
a9499fa7 TG	37
	38	static struct kobject *efi_kobj;
	39	static struct kobject *efivars_kobj;
	40
	41	/*
	42	* Let's not leave out systab information that snuck into
	43	* the efivars driver
	44	*/
	45	static ssize_t systab_show(struct kobject *kobj,
	46	struct kobj_attribute attr, char buf)
	47	{
	48	char *str = buf;
	49
	50	if (!kobj \|\| !buf)
	51	return -EINVAL;
	52
	53	if (efi.mps != EFI_INVALID_TABLE_ADDR)
	54	str += sprintf(str, "MPS=0x%lx\n", efi.mps);
	55	if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
	56	str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
	57	if (efi.acpi != EFI_INVALID_TABLE_ADDR)
	58	str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
	59	if (efi.smbios != EFI_INVALID_TABLE_ADDR)
	60	str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
	61	if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
	62	str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
	63	if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
	64	str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
	65	if (efi.uga != EFI_INVALID_TABLE_ADDR)
	66	str += sprintf(str, "UGA=0x%lx\n", efi.uga);
	67
	68	return str - buf;
	69	}
	70
	71	static struct kobj_attribute efi_attr_systab =
	72	__ATTR(systab, 0400, systab_show, NULL);
	73
	74	static struct attribute *efi_subsys_attrs[] = {
	75	&efi_attr_systab.attr,
	76	NULL, /* maybe more in the future? */
	77	};
	78
	79	static struct attribute_group efi_subsys_attr_group = {
	80	.attrs = efi_subsys_attrs,
	81	};
	82
	83	static struct efivars generic_efivars;
	84	static struct efivar_operations generic_ops;
	85
	86	static int generic_ops_register(void)
	87	{
	88	generic_ops.get_variable = efi.get_variable;
	89	generic_ops.set_variable = efi.set_variable;
	90	generic_ops.get_next_variable = efi.get_next_variable;
a614e192	91	generic_ops.query_variable_store = efi_query_variable_store;
a9499fa7 TG	92
	93	return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
	94	}
	95
	96	static void generic_ops_unregister(void)
	97	{
	98	efivars_unregister(&generic_efivars);
	99	}
	100
	101	/*
	102	* We register the efi subsystem with the firmware subsystem and the
	103	* efivars subsystem with the efi subsystem, if the system was booted with
	104	* EFI.
	105	*/
	106	static int __init efisubsys_init(void)
	107	{
	108	int error;
	109
	110	if (!efi_enabled(EFI_BOOT))
	111	return 0;
	112
	113	/* We register the efi directory at /sys/firmware/efi */
	114	efi_kobj = kobject_create_and_add("efi", firmware_kobj);
	115	if (!efi_kobj) {
	116	pr_err("efi: Firmware registration failed.\n");
	117	return -ENOMEM;
	118	}
	119
	120	error = generic_ops_register();
	121	if (error)
	122	goto err_put;
	123
	124	error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
	125	if (error) {
	126	pr_err("efi: Sysfs attribute export failed with error %d.\n",
	127	error);
	128	goto err_unregister;
	129	}
	130
	131	/* and the standard mountpoint for efivarfs */
	132	efivars_kobj = kobject_create_and_add("efivars", efi_kobj);
	133	if (!efivars_kobj) {
	134	pr_err("efivars: Subsystem registration failed.\n");
	135	error = -ENOMEM;
	136	goto err_remove_group;
	137	}
	138
	139	return 0;
	140
	141	err_remove_group:
	142	sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
	143	err_unregister:
	144	generic_ops_unregister();
	145	err_put:
	146	kobject_put(efi_kobj);
	147	return error;
	148	}
	149
	150	subsys_initcall(efisubsys_init);
272686bf LL	151
272686bf LL	152
258f6fd7 LL	153	/*
	154	* We can't ioremap data in EFI boot services RAM, because we've already mapped
	155	* it as RAM. So, look it up in the existing EFI memory map instead. Only
	156	* callable after efi_enter_virtual_mode and before efi_free_boot_services.
	157	*/
	158	void __iomem *efi_lookup_mapped_addr(u64 phys_addr)
	159	{
	160	struct efi_memory_map *map;
	161	void *p;
	162	map = efi.memmap;
	163	if (!map)
	164	return NULL;
	165	if (WARN_ON(!map->map))
	166	return NULL;
	167	for (p = map->map; p < map->map_end; p += map->desc_size) {
	168	efi_memory_desc_t *md = p;
	169	u64 size = md->num_pages << EFI_PAGE_SHIFT;
	170	u64 end = md->phys_addr + size;
	171	if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
	172	md->type != EFI_BOOT_SERVICES_CODE &&
	173	md->type != EFI_BOOT_SERVICES_DATA)
	174	continue;
	175	if (!md->virt_addr)
	176	continue;
	177	if (phys_addr >= md->phys_addr && phys_addr < end) {
	178	phys_addr += md->virt_addr - md->phys_addr;
	179	return (__force void __iomem *)(unsigned long)phys_addr;
	180	}
	181	}
	182	return NULL;
	183	}
	184
272686bf LL	185	static __initdata efi_config_table_type_t common_tables[] = {
	186	{ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
	187	{ACPI_TABLE_GUID, "ACPI", &efi.acpi},
	188	{HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
	189	{MPS_TABLE_GUID, "MPS", &efi.mps},
	190	{SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
	191	{SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
	192	{UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
	193	{NULL_GUID, NULL, 0},
	194	};
	195
	196	static __init int match_config_table(efi_guid_t *guid,
	197	unsigned long table,
	198	efi_config_table_type_t *table_types)
	199	{
	200	u8 str[EFI_VARIABLE_GUID_LEN + 1];
	201	int i;
	202
	203	if (table_types) {
	204	efi_guid_unparse(guid, str);
	205
	206	for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
	207	efi_guid_unparse(&table_types[i].guid, str);
	208
	209	if (!efi_guidcmp(*guid, table_types[i].guid)) {
	210	*(table_types[i].ptr) = table;
	211	pr_cont(" %s=0x%lx ",
	212	table_types[i].name, table);
	213	return 1;
	214	}
	215	}
	216	}
	217
	218	return 0;
	219	}
	220
	221	int __init efi_config_init(efi_config_table_type_t *arch_tables)
	222	{
	223	void config_tables, tablep;
	224	int i, sz;
	225
	226	if (efi_enabled(EFI_64BIT))
	227	sz = sizeof(efi_config_table_64_t);
	228	else
	229	sz = sizeof(efi_config_table_32_t);
	230
	231	/*
	232	* Let's see what config tables the firmware passed to us.
	233	*/
	234	config_tables = early_memremap(efi.systab->tables,
	235	efi.systab->nr_tables * sz);
	236	if (config_tables == NULL) {
	237	pr_err("Could not map Configuration table!\n");
	238	return -ENOMEM;
	239	}
	240
	241	tablep = config_tables;
	242	pr_info("");
	243	for (i = 0; i < efi.systab->nr_tables; i++) {
	244	efi_guid_t guid;
	245	unsigned long table;
	246
	247	if (efi_enabled(EFI_64BIT)) {
	248	u64 table64;
249	guid = ((efi_config_table_64_t *)tablep)->guid;
250	table64 = ((efi_config_table_64_t *)tablep)->table;
251	table = table64;
252	#ifndef CONFIG_64BIT
253	if (table64 >> 32) {
254	pr_cont("\n");
255	pr_err("Table located above 4GB, disabling EFI.\n");
256	early_iounmap(config_tables,
257	efi.systab->nr_tables * sz);
258	return -EINVAL;
259	}
260	#endif
261	} else {
262	guid = ((efi_config_table_32_t *)tablep)->guid;
263	table = ((efi_config_table_32_t *)tablep)->table;
264	}
265
266	if (!match_config_table(&guid, table, common_tables))
267	match_config_table(&guid, table, arch_tables);
268
269	tablep += sz;
270	}
271	pr_cont("\n");
272	early_iounmap(config_tables, efi.systab->nr_tables * sz);
273	return 0;
274	}