linux/drivers/firmware/efi/efi.c

1016 lines
25 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/efi.h>
#include <linux/of.h>
#include <linux/io.h>
#include <linux/kexec.h>
#include <linux/platform_device.h>
#include <linux/random.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/ucs2_string.h>
#include <linux/memblock.h>
#include <linux/security.h>
#include <asm/early_ioremap.h>
struct efi __read_mostly efi = {
.runtime_supported_mask = EFI_RT_SUPPORTED_ALL,
.acpi = EFI_INVALID_TABLE_ADDR,
.acpi20 = EFI_INVALID_TABLE_ADDR,
.smbios = EFI_INVALID_TABLE_ADDR,
.smbios3 = EFI_INVALID_TABLE_ADDR,
.esrt = EFI_INVALID_TABLE_ADDR,
.tpm_log = EFI_INVALID_TABLE_ADDR,
.tpm_final_log = EFI_INVALID_TABLE_ADDR,
};
EXPORT_SYMBOL(efi);
unsigned long __ro_after_init efi_rng_seed = EFI_INVALID_TABLE_ADDR;
static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR;
static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR;
struct mm_struct efi_mm = {
.mm_rb = RB_ROOT,
.mm_users = ATOMIC_INIT(2),
.mm_count = ATOMIC_INIT(1),
.mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
.page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
.mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
.cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0},
};
struct workqueue_struct *efi_rts_wq;
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;
}
bool __pure __efi_soft_reserve_enabled(void)
{
return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE);
}
static int __init parse_efi_cmdline(char *str)
{
if (!str) {
pr_warn("need at least one option\n");
return -EINVAL;
}
if (parse_option_str(str, "debug"))
set_bit(EFI_DBG, &efi.flags);
if (parse_option_str(str, "noruntime"))
disable_runtime = true;
if (parse_option_str(str, "nosoftreserve"))
set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags);
return 0;
}
early_param("efi", parse_efi_cmdline);
struct kobject *efi_kobj;
/*
* Let's not leave out systab information that snuck into
* the efivars driver
* Note, do not add more fields in systab sysfs file as it breaks sysfs
* one value per file rule!
*/
static ssize_t systab_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
char *str = buf;
if (!kobj || !buf)
return -EINVAL;
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 both SMBIOS and SMBIOS3 entry points are implemented, the
* SMBIOS3 entry point shall be preferred, so we list it first to
* let applications stop parsing after the first match.
*/
if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
if (efi.smbios != EFI_INVALID_TABLE_ADDR)
str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
if (IS_ENABLED(CONFIG_IA64) || IS_ENABLED(CONFIG_X86)) {
extern char *efi_systab_show_arch(char *str);
str = efi_systab_show_arch(str);
}
return str - buf;
}
static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
static ssize_t fw_platform_size_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
}
extern __weak struct kobj_attribute efi_attr_fw_vendor;
extern __weak struct kobj_attribute efi_attr_runtime;
extern __weak struct kobj_attribute efi_attr_config_table;
static struct kobj_attribute efi_attr_fw_platform_size =
__ATTR_RO(fw_platform_size);
static struct attribute *efi_subsys_attrs[] = {
&efi_attr_systab.attr,
&efi_attr_fw_platform_size.attr,
&efi_attr_fw_vendor.attr,
&efi_attr_runtime.attr,
&efi_attr_config_table.attr,
NULL,
};
umode_t __weak efi_attr_is_visible(struct kobject *kobj, struct attribute *attr,
int n)
{
return attr->mode;
}
static const 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.set_variable_nonblocking = efi.set_variable_nonblocking;
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);
}
#if IS_ENABLED(CONFIG_ACPI)
#define EFIVAR_SSDT_NAME_MAX 16
static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
static int __init efivar_ssdt_setup(char *str)
{
int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
if (ret)
return ret;
if (strlen(str) < sizeof(efivar_ssdt))
memcpy(efivar_ssdt, str, strlen(str));
else
pr_warn("efivar_ssdt: name too long: %s\n", str);
return 0;
}
__setup("efivar_ssdt=", efivar_ssdt_setup);
static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
unsigned long name_size, void *data)
{
struct efivar_entry *entry;
struct list_head *list = data;
char utf8_name[EFIVAR_SSDT_NAME_MAX];
int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
ucs2_as_utf8(utf8_name, name, limit - 1);
if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
return 0;
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
return 0;
memcpy(entry->var.VariableName, name, name_size);
memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
efivar_entry_add(entry, list);
return 0;
}
static __init int efivar_ssdt_load(void)
{
LIST_HEAD(entries);
struct efivar_entry *entry, *aux;
unsigned long size;
void *data;
int ret;
if (!efivar_ssdt[0])
return 0;
ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
list_for_each_entry_safe(entry, aux, &entries, list) {
pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
&entry->var.VendorGuid);
list_del(&entry->list);
ret = efivar_entry_size(entry, &size);
if (ret) {
pr_err("failed to get var size\n");
goto free_entry;
}
data = kmalloc(size, GFP_KERNEL);
if (!data) {
ret = -ENOMEM;
goto free_entry;
}
ret = efivar_entry_get(entry, NULL, &size, data);
if (ret) {
pr_err("failed to get var data\n");
goto free_data;
}
ret = acpi_load_table(data, NULL);
if (ret) {
pr_err("failed to load table: %d\n", ret);
goto free_data;
}
goto free_entry;
free_data:
kfree(data);
free_entry:
kfree(entry);
}
return ret;
}
#else
static inline int efivar_ssdt_load(void) { return 0; }
#endif
#ifdef CONFIG_DEBUG_FS
#define EFI_DEBUGFS_MAX_BLOBS 32
static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS];
static void __init efi_debugfs_init(void)
{
struct dentry *efi_debugfs;
efi_memory_desc_t *md;
char name[32];
int type_count[EFI_BOOT_SERVICES_DATA + 1] = {};
int i = 0;
efi_debugfs = debugfs_create_dir("efi", NULL);
if (IS_ERR_OR_NULL(efi_debugfs))
return;
for_each_efi_memory_desc(md) {
switch (md->type) {
case EFI_BOOT_SERVICES_CODE:
snprintf(name, sizeof(name), "boot_services_code%d",
type_count[md->type]++);
break;
case EFI_BOOT_SERVICES_DATA:
snprintf(name, sizeof(name), "boot_services_data%d",
type_count[md->type]++);
break;
default:
continue;
}
if (i >= EFI_DEBUGFS_MAX_BLOBS) {
pr_warn("More then %d EFI boot service segments, only showing first %d in debugfs\n",
EFI_DEBUGFS_MAX_BLOBS, EFI_DEBUGFS_MAX_BLOBS);
break;
}
debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT;
debugfs_blob[i].data = memremap(md->phys_addr,
debugfs_blob[i].size,
MEMREMAP_WB);
if (!debugfs_blob[i].data)
continue;
debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]);
i++;
}
}
#else
static inline void efi_debugfs_init(void) {}
#endif
/*
* 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_RUNTIME_SERVICES))
efi.runtime_supported_mask = 0;
if (!efi_enabled(EFI_BOOT))
return 0;
if (efi.runtime_supported_mask) {
/*
* Since we process only one efi_runtime_service() at a time, an
* ordered workqueue (which creates only one execution context)
* should suffice for all our needs.
*/
efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
if (!efi_rts_wq) {
pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
efi.runtime_supported_mask = 0;
return 0;
}
}
if (efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES))
platform_device_register_simple("rtc-efi", 0, NULL, 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;
}
if (efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES)) {
efivar_ssdt_load();
error = generic_ops_register();
if (error)
goto err_put;
platform_device_register_simple("efivars", 0, NULL, 0);
}
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 */
error = sysfs_create_mount_point(efi_kobj, "efivars");
if (error) {
pr_err("efivars: Subsystem registration failed.\n");
goto err_remove_group;
}
if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
efi_debugfs_init();
return 0;
err_remove_group:
sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
err_unregister:
if (efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES))
generic_ops_unregister();
err_put:
kobject_put(efi_kobj);
return error;
}
subsys_initcall(efisubsys_init);
/*
* Find the efi memory descriptor for a given physical address. Given a
* physical address, determine if it exists within an EFI Memory Map entry,
* and if so, populate the supplied memory descriptor with the appropriate
* data.
*/
int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
{
efi_memory_desc_t *md;
if (!efi_enabled(EFI_MEMMAP)) {
pr_err_once("EFI_MEMMAP is not enabled.\n");
return -EINVAL;
}
if (!out_md) {
pr_err_once("out_md is null.\n");
return -EINVAL;
}
for_each_efi_memory_desc(md) {
u64 size;
u64 end;
size = md->num_pages << EFI_PAGE_SHIFT;
end = md->phys_addr + size;
if (phys_addr >= md->phys_addr && phys_addr < end) {
memcpy(out_md, md, sizeof(*out_md));
return 0;
}
}
return -ENOENT;
}
/*
* Calculate the highest address of an efi memory descriptor.
*/
u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
{
u64 size = md->num_pages << EFI_PAGE_SHIFT;
u64 end = md->phys_addr + size;
return end;
}
void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
/**
* efi_mem_reserve - Reserve an EFI memory region
* @addr: Physical address to reserve
* @size: Size of reservation
*
* Mark a region as reserved from general kernel allocation and
* prevent it being released by efi_free_boot_services().
*
* This function should be called drivers once they've parsed EFI
* configuration tables to figure out where their data lives, e.g.
* efi_esrt_init().
*/
void __init efi_mem_reserve(phys_addr_t addr, u64 size)
{
if (!memblock_is_region_reserved(addr, size))
memblock_reserve(addr, size);
/*
* Some architectures (x86) reserve all boot services ranges
* until efi_free_boot_services() because of buggy firmware
* implementations. This means the above memblock_reserve() is
* superfluous on x86 and instead what it needs to do is
* ensure the @start, @size is not freed.
*/
efi_arch_mem_reserve(addr, size);
}
static const efi_config_table_type_t common_tables[] __initconst = {
{ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
{ACPI_TABLE_GUID, "ACPI", &efi.acpi},
{SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
{SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
{EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
{EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi_mem_attr_table},
{LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi_rng_seed},
{LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log},
{LINUX_EFI_TPM_FINAL_LOG_GUID, "TPMFinalLog", &efi.tpm_final_log},
{LINUX_EFI_MEMRESERVE_TABLE_GUID, "MEMRESERVE", &mem_reserve},
{EFI_RT_PROPERTIES_TABLE_GUID, "RTPROP", &rt_prop},
#ifdef CONFIG_EFI_RCI2_TABLE
{DELLEMC_EFI_RCI2_TABLE_GUID, NULL, &rci2_table_phys},
#endif
{NULL_GUID, NULL, NULL},
};
static __init int match_config_table(const efi_guid_t *guid,
unsigned long table,
const efi_config_table_type_t *table_types)
{
int i;
if (table_types) {
for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
if (!efi_guidcmp(*guid, table_types[i].guid)) {
*(table_types[i].ptr) = table;
if (table_types[i].name)
pr_cont(" %s=0x%lx ",
table_types[i].name, table);
return 1;
}
}
}
return 0;
}
int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
int count,
const efi_config_table_type_t *arch_tables)
{
const efi_config_table_64_t *tbl64 = (void *)config_tables;
const efi_config_table_32_t *tbl32 = (void *)config_tables;
const efi_guid_t *guid;
unsigned long table;
int i;
pr_info("");
for (i = 0; i < count; i++) {
if (!IS_ENABLED(CONFIG_X86)) {
guid = &config_tables[i].guid;
table = (unsigned long)config_tables[i].table;
} else if (efi_enabled(EFI_64BIT)) {
guid = &tbl64[i].guid;
table = tbl64[i].table;
if (IS_ENABLED(CONFIG_X86_32) &&
tbl64[i].table > U32_MAX) {
pr_cont("\n");
pr_err("Table located above 4GB, disabling EFI.\n");
return -EINVAL;
}
} else {
guid = &tbl32[i].guid;
table = tbl32[i].table;
}
if (!match_config_table(guid, table, common_tables))
match_config_table(guid, table, arch_tables);
}
pr_cont("\n");
set_bit(EFI_CONFIG_TABLES, &efi.flags);
if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) {
struct linux_efi_random_seed *seed;
u32 size = 0;
seed = early_memremap(efi_rng_seed, sizeof(*seed));
if (seed != NULL) {
size = READ_ONCE(seed->size);
early_memunmap(seed, sizeof(*seed));
} else {
pr_err("Could not map UEFI random seed!\n");
}
if (size > 0) {
seed = early_memremap(efi_rng_seed,
sizeof(*seed) + size);
if (seed != NULL) {
pr_notice("seeding entropy pool\n");
add_bootloader_randomness(seed->bits, size);
early_memunmap(seed, sizeof(*seed) + size);
} else {
pr_err("Could not map UEFI random seed!\n");
}
}
}
if (!IS_ENABLED(CONFIG_X86_32) && efi_enabled(EFI_MEMMAP))
efi_memattr_init();
efi_tpm_eventlog_init();
if (mem_reserve != EFI_INVALID_TABLE_ADDR) {
unsigned long prsv = mem_reserve;
while (prsv) {
struct linux_efi_memreserve *rsv;
u8 *p;
/*
* Just map a full page: that is what we will get
* anyway, and it permits us to map the entire entry
* before knowing its size.
*/
p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
PAGE_SIZE);
if (p == NULL) {
pr_err("Could not map UEFI memreserve entry!\n");
return -ENOMEM;
}
rsv = (void *)(p + prsv % PAGE_SIZE);
/* reserve the entry itself */
memblock_reserve(prsv, EFI_MEMRESERVE_SIZE(rsv->size));
for (i = 0; i < atomic_read(&rsv->count); i++) {
memblock_reserve(rsv->entry[i].base,
rsv->entry[i].size);
}
prsv = rsv->next;
early_memunmap(p, PAGE_SIZE);
}
}
if (rt_prop != EFI_INVALID_TABLE_ADDR) {
efi_rt_properties_table_t *tbl;
tbl = early_memremap(rt_prop, sizeof(*tbl));
if (tbl) {
efi.runtime_supported_mask &= tbl->runtime_services_supported;
early_memunmap(tbl, sizeof(*tbl));
}
}
return 0;
}
int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr,
int min_major_version)
{
if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) {
pr_err("System table signature incorrect!\n");
return -EINVAL;
}
if ((systab_hdr->revision >> 16) < min_major_version)
pr_err("Warning: System table version %d.%02d, expected %d.00 or greater!\n",
systab_hdr->revision >> 16,
systab_hdr->revision & 0xffff,
min_major_version);
return 0;
}
#ifndef CONFIG_IA64
static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor,
size_t size)
{
const efi_char16_t *ret;
ret = early_memremap_ro(fw_vendor, size);
if (!ret)
pr_err("Could not map the firmware vendor!\n");
return ret;
}
static void __init unmap_fw_vendor(const void *fw_vendor, size_t size)
{
early_memunmap((void *)fw_vendor, size);
}
#else
#define map_fw_vendor(p, s) __va(p)
#define unmap_fw_vendor(v, s)
#endif
void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
unsigned long fw_vendor)
{
char vendor[100] = "unknown";
const efi_char16_t *c16;
size_t i;
c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t));
if (c16) {
for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
vendor[i] = c16[i];
vendor[i] = '\0';
unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t));
}
pr_info("EFI v%u.%.02u by %s\n",
systab_hdr->revision >> 16,
systab_hdr->revision & 0xffff,
vendor);
}
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",
"Persistent Memory",
};
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_RO |
EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
EFI_MEMORY_NV | EFI_MEMORY_SP |
EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
snprintf(pos, size, "|attr=0x%016llx]",
(unsigned long long)attr);
else
snprintf(pos, size,
"|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
attr & EFI_MEMORY_SP ? "SP" : "",
attr & EFI_MEMORY_NV ? "NV" : "",
attr & EFI_MEMORY_XP ? "XP" : "",
attr & EFI_MEMORY_RP ? "RP" : "",
attr & EFI_MEMORY_WP ? "WP" : "",
attr & EFI_MEMORY_RO ? "RO" : "",
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;
}
/*
* IA64 has a funky EFI memory map that doesn't work the same way as
* other architectures.
*/
#ifndef CONFIG_IA64
/*
* efi_mem_attributes - lookup memmap attributes for physical address
* @phys_addr: the physical address to lookup
*
* Search in the EFI memory map for the region covering
* @phys_addr. Returns the EFI memory attributes if the region
* was found in the memory map, 0 otherwise.
*/
u64 efi_mem_attributes(unsigned long phys_addr)
{
efi_memory_desc_t *md;
if (!efi_enabled(EFI_MEMMAP))
return 0;
for_each_efi_memory_desc(md) {
if ((md->phys_addr <= phys_addr) &&
(phys_addr < (md->phys_addr +
(md->num_pages << EFI_PAGE_SHIFT))))
return md->attribute;
}
return 0;
}
/*
* efi_mem_type - lookup memmap type for physical address
* @phys_addr: the physical address to lookup
*
* Search in the EFI memory map for the region covering @phys_addr.
* Returns the EFI memory type if the region was found in the memory
* map, -EINVAL otherwise.
*/
int efi_mem_type(unsigned long phys_addr)
{
const efi_memory_desc_t *md;
if (!efi_enabled(EFI_MEMMAP))
return -ENOTSUPP;
for_each_efi_memory_desc(md) {
if ((md->phys_addr <= phys_addr) &&
(phys_addr < (md->phys_addr +
(md->num_pages << EFI_PAGE_SHIFT))))
return md->type;
}
return -EINVAL;
}
#endif
int efi_status_to_err(efi_status_t status)
{
int err;
switch (status) {
case EFI_SUCCESS:
err = 0;
break;
case EFI_INVALID_PARAMETER:
err = -EINVAL;
break;
case EFI_OUT_OF_RESOURCES:
err = -ENOSPC;
break;
case EFI_DEVICE_ERROR:
err = -EIO;
break;
case EFI_WRITE_PROTECTED:
err = -EROFS;
break;
case EFI_SECURITY_VIOLATION:
err = -EACCES;
break;
case EFI_NOT_FOUND:
err = -ENOENT;
break;
case EFI_ABORTED:
err = -EINTR;
break;
default:
err = -EINVAL;
}
return err;
}
static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
static int __init efi_memreserve_map_root(void)
{
if (mem_reserve == EFI_INVALID_TABLE_ADDR)
return -ENODEV;
efi_memreserve_root = memremap(mem_reserve,
sizeof(*efi_memreserve_root),
MEMREMAP_WB);
if (WARN_ON_ONCE(!efi_memreserve_root))
return -ENOMEM;
return 0;
}
static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size)
{
struct resource *res, *parent;
res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
if (!res)
return -ENOMEM;
res->name = "reserved";
res->flags = IORESOURCE_MEM;
res->start = addr;
res->end = addr + size - 1;
/* we expect a conflict with a 'System RAM' region */
parent = request_resource_conflict(&iomem_resource, res);
return parent ? request_resource(parent, res) : 0;
}
int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
{
struct linux_efi_memreserve *rsv;
unsigned long prsv;
int rc, index;
if (efi_memreserve_root == (void *)ULONG_MAX)
return -ENODEV;
if (!efi_memreserve_root) {
rc = efi_memreserve_map_root();
if (rc)
return rc;
}
/* first try to find a slot in an existing linked list entry */
for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
if (index < rsv->size) {
rsv->entry[index].base = addr;
rsv->entry[index].size = size;
memunmap(rsv);
return efi_mem_reserve_iomem(addr, size);
}
memunmap(rsv);
}
/* no slot found - allocate a new linked list entry */
rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
if (!rsv)
return -ENOMEM;
rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K);
if (rc) {
free_page((unsigned long)rsv);
return rc;
}
/*
* The memremap() call above assumes that a linux_efi_memreserve entry
* never crosses a page boundary, so let's ensure that this remains true
* even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
* using SZ_4K explicitly in the size calculation below.
*/
rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
atomic_set(&rsv->count, 1);
rsv->entry[0].base = addr;
rsv->entry[0].size = size;
spin_lock(&efi_mem_reserve_persistent_lock);
rsv->next = efi_memreserve_root->next;
efi_memreserve_root->next = __pa(rsv);
spin_unlock(&efi_mem_reserve_persistent_lock);
return efi_mem_reserve_iomem(addr, size);
}
static int __init efi_memreserve_root_init(void)
{
if (efi_memreserve_root)
return 0;
if (efi_memreserve_map_root())
efi_memreserve_root = (void *)ULONG_MAX;
return 0;
}
early_initcall(efi_memreserve_root_init);
#ifdef CONFIG_KEXEC
static int update_efi_random_seed(struct notifier_block *nb,
unsigned long code, void *unused)
{
struct linux_efi_random_seed *seed;
u32 size = 0;
if (!kexec_in_progress)
return NOTIFY_DONE;
seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB);
if (seed != NULL) {
size = min(seed->size, EFI_RANDOM_SEED_SIZE);
memunmap(seed);
} else {
pr_err("Could not map UEFI random seed!\n");
}
if (size > 0) {
seed = memremap(efi_rng_seed, sizeof(*seed) + size,
MEMREMAP_WB);
if (seed != NULL) {
seed->size = size;
get_random_bytes(seed->bits, seed->size);
memunmap(seed);
} else {
pr_err("Could not map UEFI random seed!\n");
}
}
return NOTIFY_DONE;
}
static struct notifier_block efi_random_seed_nb = {
.notifier_call = update_efi_random_seed,
};
static int __init register_update_efi_random_seed(void)
{
if (efi_rng_seed == EFI_INVALID_TABLE_ADDR)
return 0;
return register_reboot_notifier(&efi_random_seed_nb);
}
late_initcall(register_update_efi_random_seed);
#endif