- 根目录:
- 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/of.h>
#include <linux/of_fdt.h>
#include <linux/io.h>
#include <linux/platform_device.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,
.smbios3 = 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 bool disable_runtime;
static int __init setup_noefi(char *arg)
{
disable_runtime = true;
return 0;
}
early_param("noefi", setup_noefi);
bool efi_runtime_disabled(void)
{
return disable_runtime;
}
static int __init parse_efi_cmdline(char *str)
{
if (parse_option_str(str, "noruntime"))
disable_runtime = true;
return 0;
}
early_param("efi", parse_efi_cmdline);
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.smbios3 != EFI_INVALID_TABLE_ADDR)
str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
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)
{
if (attr == &efi_attr_fw_vendor.attr) {
if (efi_enabled(EFI_PARAVIRT) ||
efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
return 0;
} else if (attr == &efi_attr_runtime.attr) {
if (efi.runtime == EFI_INVALID_TABLE_ADDR)
return 0;
} else if (attr == &efi_attr_config_table.attr) {
if (efi.config_table == EFI_INVALID_TABLE_ADDR)
return 0;
}
return attr->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},
{SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
{UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
{NULL_GUID, NULL, NULL},
};
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_parse_tables(void *config_tables, int count, int sz,
efi_config_table_type_t *arch_tables)
{
void *tablep;
int i;
tablep = config_tables;
pr_info("");
for (i = 0; i < count; 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");
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");
set_bit(EFI_CONFIG_TABLES, &efi.flags);
return 0;
}
int __init efi_config_init(efi_config_table_type_t *arch_tables)
{
void *config_tables;
int sz, ret;
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;
}
ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
arch_tables);
early_memunmap(config_tables, efi.systab->nr_tables * sz);
return ret;
}
#ifdef CONFIG_EFI_VARS_MODULE
static int __init efi_load_efivars(void)
{
struct platform_device *pdev;
if (!efi_enabled(EFI_RUNTIME_SERVICES))
return 0;
pdev = platform_device_register_simple("efivars", 0, NULL, 0);
return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
}
device_initcall(efi_load_efivars);
#endif
#ifdef CONFIG_EFI_PARAMS_FROM_FDT
#define UEFI_PARAM(name, prop, field) \
{ \
{ name }, \
{ prop }, \
offsetof(struct efi_fdt_params, field), \
FIELD_SIZEOF(struct efi_fdt_params, field) \
}
static __initdata struct {
const char name[32];
const char propname[32];
int offset;
int size;
} dt_params[] = {
UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
};
struct param_info {
int verbose;
int found;
void *params;
};
static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
int depth, void *data)
{
struct param_info *info = data;
const void *prop;
void *dest;
u64 val;
int i, len;
if (depth != 1 ||
(strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
return 0;
for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len);
if (!prop)
return 0;
dest = info->params + dt_params[i].offset;
info->found++;
val = of_read_number(prop, len / sizeof(u32));
if (dt_params[i].size == sizeof(u32))
*(u32 *)dest = val;
else
*(u64 *)dest = val;
if (info->verbose)
pr_info(" %s: 0x%0*llx\n", dt_params[i].name,
dt_params[i].size * 2, val);
}
return 1;
}
int __init efi_get_fdt_params(struct efi_fdt_params *params, int verbose)
{
struct param_info info;
int ret;
pr_info("Getting EFI parameters from FDT:\n");
info.verbose = verbose;
info.found = 0;
info.params = params;
ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
if (!info.found)
pr_info("UEFI not found.\n");
else if (!ret)
pr_err("Can't find '%s' in device tree!\n",
dt_params[info.found].name);
return ret;
}
#endif /* CONFIG_EFI_PARAMS_FROM_FDT */
static __initdata char memory_type_name[][20] = {
"Reserved",
"Loader Code",
"Loader Data",
"Boot Code",
"Boot Data",
"Runtime Code",
"Runtime Data",
"Conventional Memory",
"Unusable Memory",
"ACPI Reclaim Memory",
"ACPI Memory NVS",
"Memory Mapped I/O",
"MMIO Port Space",
"PAL Code"
};
char * __init efi_md_typeattr_format(char *buf, size_t size,
const efi_memory_desc_t *md)
{
char *pos;
int type_len;
u64 attr;
pos = buf;
if (md->type >= ARRAY_SIZE(memory_type_name))
type_len = snprintf(pos, size, "[type=%u", md->type);
else
type_len = snprintf(pos, size, "[%-*s",
(int)(sizeof(memory_type_name[0]) - 1),
memory_type_name[md->type]);
if (type_len >= size)
return buf;
pos += type_len;
size -= type_len;
attr = md->attribute;
if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_WP |
EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME))
snprintf(pos, size, "|attr=0x%016llx]",
(unsigned long long)attr);
else
snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
attr & EFI_MEMORY_XP ? "XP" : "",
attr & EFI_MEMORY_RP ? "RP" : "",
attr & EFI_MEMORY_WP ? "WP" : "",
attr & EFI_MEMORY_UCE ? "UCE" : "",
attr & EFI_MEMORY_WB ? "WB" : "",
attr & EFI_MEMORY_WT ? "WT" : "",
attr & EFI_MEMORY_WC ? "WC" : "",
attr & EFI_MEMORY_UC ? "UC" : "");
return buf;
}