drivers/firmware/efi/efi.c - arm/linux-arm-legacy - Git at Google

 /*
  * 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,
 	.fw_vendor  = EFI_INVALID_TABLE_ADDR,
 	.runtime    = EFI_INVALID_TABLE_ADDR,
 	.config_table  = 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);

 #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,
 	&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;
 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;
 	}

 	error = efi_runtime_map_init(efi_kobj);
 	if (error)
 		goto err_remove_group;

 	/* 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;
 }
	/*
	* 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,
	.fw_vendor = EFI_INVALID_TABLE_ADDR,
	.runtime = EFI_INVALID_TABLE_ADDR,
	.config_table = 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);

	#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,
	&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;
	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;
	}

	error = efi_runtime_map_init(efi_kobj);
	if (error)
	goto err_remove_group;

	/* 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;
	}