1 // SPDX-License-Identifier: GPL-2.0-only
3 * efi.c - EFI subsystem
5 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
6 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
7 * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
9 * This code registers /sys/firmware/efi{,/efivars} when EFI is supported,
10 * allowing the efivarfs to be mounted or the efivars module to be loaded.
11 * The existance of /sys/firmware/efi may also be used by userspace to
12 * determine that the system supports EFI.
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 #include <linux/kobject.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/device.h>
21 #include <linux/efi.h>
23 #include <linux/of_fdt.h>
25 #include <linux/kexec.h>
26 #include <linux/platform_device.h>
27 #include <linux/random.h>
28 #include <linux/reboot.h>
29 #include <linux/slab.h>
30 #include <linux/acpi.h>
31 #include <linux/ucs2_string.h>
32 #include <linux/memblock.h>
33 #include <linux/security.h>
35 #include <asm/early_ioremap.h>
37 struct efi __read_mostly efi = {
38 .mps = EFI_INVALID_TABLE_ADDR,
39 .acpi = EFI_INVALID_TABLE_ADDR,
40 .acpi20 = EFI_INVALID_TABLE_ADDR,
41 .smbios = EFI_INVALID_TABLE_ADDR,
42 .smbios3 = EFI_INVALID_TABLE_ADDR,
43 .boot_info = EFI_INVALID_TABLE_ADDR,
44 .hcdp = EFI_INVALID_TABLE_ADDR,
45 .uga = EFI_INVALID_TABLE_ADDR,
46 .fw_vendor = EFI_INVALID_TABLE_ADDR,
47 .runtime = EFI_INVALID_TABLE_ADDR,
48 .config_table = EFI_INVALID_TABLE_ADDR,
49 .esrt = EFI_INVALID_TABLE_ADDR,
50 .properties_table = EFI_INVALID_TABLE_ADDR,
51 .mem_attr_table = EFI_INVALID_TABLE_ADDR,
52 .rng_seed = EFI_INVALID_TABLE_ADDR,
53 .tpm_log = EFI_INVALID_TABLE_ADDR,
54 .tpm_final_log = EFI_INVALID_TABLE_ADDR,
55 .mem_reserve = EFI_INVALID_TABLE_ADDR,
59 struct mm_struct efi_mm = {
61 .mm_users = ATOMIC_INIT(2),
62 .mm_count = ATOMIC_INIT(1),
63 .mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
64 .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
65 .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
66 .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0},
69 struct workqueue_struct *efi_rts_wq;
71 static bool disable_runtime;
72 static int __init setup_noefi(char *arg)
74 disable_runtime = true;
77 early_param("noefi", setup_noefi);
79 bool efi_runtime_disabled(void)
81 return disable_runtime;
84 static int __init parse_efi_cmdline(char *str)
87 pr_warn("need at least one option\n");
91 if (parse_option_str(str, "debug"))
92 set_bit(EFI_DBG, &efi.flags);
94 if (parse_option_str(str, "noruntime"))
95 disable_runtime = true;
99 early_param("efi", parse_efi_cmdline);
101 struct kobject *efi_kobj;
104 * Let's not leave out systab information that snuck into
106 * Note, do not add more fields in systab sysfs file as it breaks sysfs
107 * one value per file rule!
109 static ssize_t systab_show(struct kobject *kobj,
110 struct kobj_attribute *attr, char *buf)
117 if (efi.mps != EFI_INVALID_TABLE_ADDR)
118 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
119 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
120 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
121 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
122 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
124 * If both SMBIOS and SMBIOS3 entry points are implemented, the
125 * SMBIOS3 entry point shall be preferred, so we list it first to
126 * let applications stop parsing after the first match.
128 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
129 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
130 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
131 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
132 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
133 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
134 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
135 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
136 if (efi.uga != EFI_INVALID_TABLE_ADDR)
137 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
142 static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
144 #define EFI_FIELD(var) efi.var
146 #define EFI_ATTR_SHOW(name) \
147 static ssize_t name##_show(struct kobject *kobj, \
148 struct kobj_attribute *attr, char *buf) \
150 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
153 EFI_ATTR_SHOW(fw_vendor);
154 EFI_ATTR_SHOW(runtime);
155 EFI_ATTR_SHOW(config_table);
157 static ssize_t fw_platform_size_show(struct kobject *kobj,
158 struct kobj_attribute *attr, char *buf)
160 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
163 static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
164 static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
165 static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
166 static struct kobj_attribute efi_attr_fw_platform_size =
167 __ATTR_RO(fw_platform_size);
169 static struct attribute *efi_subsys_attrs[] = {
170 &efi_attr_systab.attr,
171 &efi_attr_fw_vendor.attr,
172 &efi_attr_runtime.attr,
173 &efi_attr_config_table.attr,
174 &efi_attr_fw_platform_size.attr,
178 static umode_t efi_attr_is_visible(struct kobject *kobj,
179 struct attribute *attr, int n)
181 if (attr == &efi_attr_fw_vendor.attr) {
182 if (efi_enabled(EFI_PARAVIRT) ||
183 efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
185 } else if (attr == &efi_attr_runtime.attr) {
186 if (efi.runtime == EFI_INVALID_TABLE_ADDR)
188 } else if (attr == &efi_attr_config_table.attr) {
189 if (efi.config_table == EFI_INVALID_TABLE_ADDR)
196 static const struct attribute_group efi_subsys_attr_group = {
197 .attrs = efi_subsys_attrs,
198 .is_visible = efi_attr_is_visible,
201 static struct efivars generic_efivars;
202 static struct efivar_operations generic_ops;
204 static int generic_ops_register(void)
206 generic_ops.get_variable = efi.get_variable;
207 generic_ops.set_variable = efi.set_variable;
208 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
209 generic_ops.get_next_variable = efi.get_next_variable;
210 generic_ops.query_variable_store = efi_query_variable_store;
212 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
215 static void generic_ops_unregister(void)
217 efivars_unregister(&generic_efivars);
220 #if IS_ENABLED(CONFIG_ACPI)
221 #define EFIVAR_SSDT_NAME_MAX 16
222 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
223 static int __init efivar_ssdt_setup(char *str)
225 int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
230 if (strlen(str) < sizeof(efivar_ssdt))
231 memcpy(efivar_ssdt, str, strlen(str));
233 pr_warn("efivar_ssdt: name too long: %s\n", str);
236 __setup("efivar_ssdt=", efivar_ssdt_setup);
238 static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
239 unsigned long name_size, void *data)
241 struct efivar_entry *entry;
242 struct list_head *list = data;
243 char utf8_name[EFIVAR_SSDT_NAME_MAX];
244 int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
246 ucs2_as_utf8(utf8_name, name, limit - 1);
247 if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
250 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
254 memcpy(entry->var.VariableName, name, name_size);
255 memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
257 efivar_entry_add(entry, list);
262 static __init int efivar_ssdt_load(void)
265 struct efivar_entry *entry, *aux;
270 ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
272 list_for_each_entry_safe(entry, aux, &entries, list) {
273 pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
274 &entry->var.VendorGuid);
276 list_del(&entry->list);
278 ret = efivar_entry_size(entry, &size);
280 pr_err("failed to get var size\n");
284 data = kmalloc(size, GFP_KERNEL);
290 ret = efivar_entry_get(entry, NULL, &size, data);
292 pr_err("failed to get var data\n");
296 ret = acpi_load_table(data);
298 pr_err("failed to load table: %d\n", ret);
314 static inline int efivar_ssdt_load(void) { return 0; }
318 * We register the efi subsystem with the firmware subsystem and the
319 * efivars subsystem with the efi subsystem, if the system was booted with
322 static int __init efisubsys_init(void)
326 if (!efi_enabled(EFI_BOOT))
330 * Since we process only one efi_runtime_service() at a time, an
331 * ordered workqueue (which creates only one execution context)
332 * should suffice all our needs.
334 efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
336 pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
337 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
341 /* We register the efi directory at /sys/firmware/efi */
342 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
344 pr_err("efi: Firmware registration failed.\n");
348 error = generic_ops_register();
352 if (efi_enabled(EFI_RUNTIME_SERVICES))
355 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
357 pr_err("efi: Sysfs attribute export failed with error %d.\n",
362 error = efi_runtime_map_init(efi_kobj);
364 goto err_remove_group;
366 /* and the standard mountpoint for efivarfs */
367 error = sysfs_create_mount_point(efi_kobj, "efivars");
369 pr_err("efivars: Subsystem registration failed.\n");
370 goto err_remove_group;
376 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
378 generic_ops_unregister();
380 kobject_put(efi_kobj);
384 subsys_initcall(efisubsys_init);
387 * Find the efi memory descriptor for a given physical address. Given a
388 * physical address, determine if it exists within an EFI Memory Map entry,
389 * and if so, populate the supplied memory descriptor with the appropriate
392 int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
394 efi_memory_desc_t *md;
396 if (!efi_enabled(EFI_MEMMAP)) {
397 pr_err_once("EFI_MEMMAP is not enabled.\n");
402 pr_err_once("out_md is null.\n");
406 for_each_efi_memory_desc(md) {
410 size = md->num_pages << EFI_PAGE_SHIFT;
411 end = md->phys_addr + size;
412 if (phys_addr >= md->phys_addr && phys_addr < end) {
413 memcpy(out_md, md, sizeof(*out_md));
421 * Calculate the highest address of an efi memory descriptor.
423 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
425 u64 size = md->num_pages << EFI_PAGE_SHIFT;
426 u64 end = md->phys_addr + size;
430 void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
433 * efi_mem_reserve - Reserve an EFI memory region
434 * @addr: Physical address to reserve
435 * @size: Size of reservation
437 * Mark a region as reserved from general kernel allocation and
438 * prevent it being released by efi_free_boot_services().
440 * This function should be called drivers once they've parsed EFI
441 * configuration tables to figure out where their data lives, e.g.
444 void __init efi_mem_reserve(phys_addr_t addr, u64 size)
446 if (!memblock_is_region_reserved(addr, size))
447 memblock_reserve(addr, size);
450 * Some architectures (x86) reserve all boot services ranges
451 * until efi_free_boot_services() because of buggy firmware
452 * implementations. This means the above memblock_reserve() is
453 * superfluous on x86 and instead what it needs to do is
454 * ensure the @start, @size is not freed.
456 efi_arch_mem_reserve(addr, size);
459 static __initdata efi_config_table_type_t common_tables[] = {
460 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
461 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
462 {HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
463 {MPS_TABLE_GUID, "MPS", &efi.mps},
464 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
465 {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
466 {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
467 {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
468 {EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table},
469 {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table},
470 {LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi.rng_seed},
471 {LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log},
472 {LINUX_EFI_TPM_FINAL_LOG_GUID, "TPMFinalLog", &efi.tpm_final_log},
473 {LINUX_EFI_MEMRESERVE_TABLE_GUID, "MEMRESERVE", &efi.mem_reserve},
474 #ifdef CONFIG_EFI_RCI2_TABLE
475 {DELLEMC_EFI_RCI2_TABLE_GUID, NULL, &rci2_table_phys},
477 {NULL_GUID, NULL, NULL},
480 static __init int match_config_table(efi_guid_t *guid,
482 efi_config_table_type_t *table_types)
487 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
488 if (!efi_guidcmp(*guid, table_types[i].guid)) {
489 *(table_types[i].ptr) = table;
490 if (table_types[i].name)
491 pr_cont(" %s=0x%lx ",
492 table_types[i].name, table);
501 int __init efi_config_parse_tables(void *config_tables, int count, int sz,
502 efi_config_table_type_t *arch_tables)
507 tablep = config_tables;
509 for (i = 0; i < count; i++) {
513 if (efi_enabled(EFI_64BIT)) {
515 guid = ((efi_config_table_64_t *)tablep)->guid;
516 table64 = ((efi_config_table_64_t *)tablep)->table;
521 pr_err("Table located above 4GB, disabling EFI.\n");
526 guid = ((efi_config_table_32_t *)tablep)->guid;
527 table = ((efi_config_table_32_t *)tablep)->table;
530 if (!match_config_table(&guid, table, common_tables))
531 match_config_table(&guid, table, arch_tables);
536 set_bit(EFI_CONFIG_TABLES, &efi.flags);
538 if (efi.rng_seed != EFI_INVALID_TABLE_ADDR) {
539 struct linux_efi_random_seed *seed;
542 seed = early_memremap(efi.rng_seed, sizeof(*seed));
545 early_memunmap(seed, sizeof(*seed));
547 pr_err("Could not map UEFI random seed!\n");
550 seed = early_memremap(efi.rng_seed,
551 sizeof(*seed) + size);
553 pr_notice("seeding entropy pool\n");
554 add_device_randomness(seed->bits, seed->size);
555 early_memunmap(seed, sizeof(*seed) + size);
557 pr_err("Could not map UEFI random seed!\n");
562 if (efi_enabled(EFI_MEMMAP))
565 efi_tpm_eventlog_init();
567 /* Parse the EFI Properties table if it exists */
568 if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {
569 efi_properties_table_t *tbl;
571 tbl = early_memremap(efi.properties_table, sizeof(*tbl));
573 pr_err("Could not map Properties table!\n");
577 if (tbl->memory_protection_attribute &
578 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
579 set_bit(EFI_NX_PE_DATA, &efi.flags);
581 early_memunmap(tbl, sizeof(*tbl));
584 if (efi.mem_reserve != EFI_INVALID_TABLE_ADDR) {
585 unsigned long prsv = efi.mem_reserve;
588 struct linux_efi_memreserve *rsv;
593 * Just map a full page: that is what we will get
594 * anyway, and it permits us to map the entire entry
595 * before knowing its size.
597 p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
600 pr_err("Could not map UEFI memreserve entry!\n");
604 rsv = (void *)(p + prsv % PAGE_SIZE);
606 /* reserve the entry itself */
607 memblock_reserve(prsv, EFI_MEMRESERVE_SIZE(rsv->size));
609 for (i = 0; i < atomic_read(&rsv->count); i++) {
610 memblock_reserve(rsv->entry[i].base,
615 early_memunmap(p, PAGE_SIZE);
622 int __init efi_config_init(efi_config_table_type_t *arch_tables)
627 if (efi.systab->nr_tables == 0)
630 if (efi_enabled(EFI_64BIT))
631 sz = sizeof(efi_config_table_64_t);
633 sz = sizeof(efi_config_table_32_t);
636 * Let's see what config tables the firmware passed to us.
638 config_tables = early_memremap(efi.systab->tables,
639 efi.systab->nr_tables * sz);
640 if (config_tables == NULL) {
641 pr_err("Could not map Configuration table!\n");
645 ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
648 early_memunmap(config_tables, efi.systab->nr_tables * sz);
652 #ifdef CONFIG_EFI_VARS_MODULE
653 static int __init efi_load_efivars(void)
655 struct platform_device *pdev;
657 if (!efi_enabled(EFI_RUNTIME_SERVICES))
660 pdev = platform_device_register_simple("efivars", 0, NULL, 0);
661 return PTR_ERR_OR_ZERO(pdev);
663 device_initcall(efi_load_efivars);
666 #ifdef CONFIG_EFI_PARAMS_FROM_FDT
668 #define UEFI_PARAM(name, prop, field) \
672 offsetof(struct efi_fdt_params, field), \
673 FIELD_SIZEOF(struct efi_fdt_params, field) \
678 const char propname[32];
683 static __initdata struct params fdt_params[] = {
684 UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
685 UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
686 UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
687 UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
688 UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
691 static __initdata struct params xen_fdt_params[] = {
692 UEFI_PARAM("System Table", "xen,uefi-system-table", system_table),
693 UEFI_PARAM("MemMap Address", "xen,uefi-mmap-start", mmap),
694 UEFI_PARAM("MemMap Size", "xen,uefi-mmap-size", mmap_size),
695 UEFI_PARAM("MemMap Desc. Size", "xen,uefi-mmap-desc-size", desc_size),
696 UEFI_PARAM("MemMap Desc. Version", "xen,uefi-mmap-desc-ver", desc_ver)
699 #define EFI_FDT_PARAMS_SIZE ARRAY_SIZE(fdt_params)
701 static __initdata struct {
704 struct params *params;
706 { "hypervisor", "uefi", xen_fdt_params },
707 { "chosen", NULL, fdt_params },
716 static int __init __find_uefi_params(unsigned long node,
717 struct param_info *info,
718 struct params *params)
725 for (i = 0; i < EFI_FDT_PARAMS_SIZE; i++) {
726 prop = of_get_flat_dt_prop(node, params[i].propname, &len);
728 info->missing = params[i].name;
732 dest = info->params + params[i].offset;
735 val = of_read_number(prop, len / sizeof(u32));
737 if (params[i].size == sizeof(u32))
742 if (efi_enabled(EFI_DBG))
743 pr_info(" %s: 0x%0*llx\n", params[i].name,
744 params[i].size * 2, val);
750 static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
751 int depth, void *data)
753 struct param_info *info = data;
756 for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
757 const char *subnode = dt_params[i].subnode;
759 if (depth != 1 || strcmp(uname, dt_params[i].uname) != 0) {
760 info->missing = dt_params[i].params[0].name;
765 int err = of_get_flat_dt_subnode_by_name(node, subnode);
773 return __find_uefi_params(node, info, dt_params[i].params);
779 int __init efi_get_fdt_params(struct efi_fdt_params *params)
781 struct param_info info;
784 pr_info("Getting EFI parameters from FDT:\n");
787 info.params = params;
789 ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
791 pr_info("UEFI not found.\n");
793 pr_err("Can't find '%s' in device tree!\n",
798 #endif /* CONFIG_EFI_PARAMS_FROM_FDT */
800 static __initdata char memory_type_name[][20] = {
808 "Conventional Memory",
810 "ACPI Reclaim Memory",
818 char * __init efi_md_typeattr_format(char *buf, size_t size,
819 const efi_memory_desc_t *md)
826 if (md->type >= ARRAY_SIZE(memory_type_name))
827 type_len = snprintf(pos, size, "[type=%u", md->type);
829 type_len = snprintf(pos, size, "[%-*s",
830 (int)(sizeof(memory_type_name[0]) - 1),
831 memory_type_name[md->type]);
832 if (type_len >= size)
838 attr = md->attribute;
839 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
840 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
841 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
843 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
844 snprintf(pos, size, "|attr=0x%016llx]",
845 (unsigned long long)attr);
848 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
849 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
850 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
851 attr & EFI_MEMORY_NV ? "NV" : "",
852 attr & EFI_MEMORY_XP ? "XP" : "",
853 attr & EFI_MEMORY_RP ? "RP" : "",
854 attr & EFI_MEMORY_WP ? "WP" : "",
855 attr & EFI_MEMORY_RO ? "RO" : "",
856 attr & EFI_MEMORY_UCE ? "UCE" : "",
857 attr & EFI_MEMORY_WB ? "WB" : "",
858 attr & EFI_MEMORY_WT ? "WT" : "",
859 attr & EFI_MEMORY_WC ? "WC" : "",
860 attr & EFI_MEMORY_UC ? "UC" : "");
865 * IA64 has a funky EFI memory map that doesn't work the same way as
866 * other architectures.
870 * efi_mem_attributes - lookup memmap attributes for physical address
871 * @phys_addr: the physical address to lookup
873 * Search in the EFI memory map for the region covering
874 * @phys_addr. Returns the EFI memory attributes if the region
875 * was found in the memory map, 0 otherwise.
877 u64 efi_mem_attributes(unsigned long phys_addr)
879 efi_memory_desc_t *md;
881 if (!efi_enabled(EFI_MEMMAP))
884 for_each_efi_memory_desc(md) {
885 if ((md->phys_addr <= phys_addr) &&
886 (phys_addr < (md->phys_addr +
887 (md->num_pages << EFI_PAGE_SHIFT))))
888 return md->attribute;
894 * efi_mem_type - lookup memmap type for physical address
895 * @phys_addr: the physical address to lookup
897 * Search in the EFI memory map for the region covering @phys_addr.
898 * Returns the EFI memory type if the region was found in the memory
899 * map, EFI_RESERVED_TYPE (zero) otherwise.
901 int efi_mem_type(unsigned long phys_addr)
903 const efi_memory_desc_t *md;
905 if (!efi_enabled(EFI_MEMMAP))
908 for_each_efi_memory_desc(md) {
909 if ((md->phys_addr <= phys_addr) &&
910 (phys_addr < (md->phys_addr +
911 (md->num_pages << EFI_PAGE_SHIFT))))
918 int efi_status_to_err(efi_status_t status)
926 case EFI_INVALID_PARAMETER:
929 case EFI_OUT_OF_RESOURCES:
932 case EFI_DEVICE_ERROR:
935 case EFI_WRITE_PROTECTED:
938 case EFI_SECURITY_VIOLATION:
954 static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
955 static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
957 static int __init efi_memreserve_map_root(void)
959 if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
962 efi_memreserve_root = memremap(efi.mem_reserve,
963 sizeof(*efi_memreserve_root),
965 if (WARN_ON_ONCE(!efi_memreserve_root))
970 int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
972 struct linux_efi_memreserve *rsv;
976 if (efi_memreserve_root == (void *)ULONG_MAX)
979 if (!efi_memreserve_root) {
980 rc = efi_memreserve_map_root();
985 /* first try to find a slot in an existing linked list entry */
986 for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
987 rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
988 index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
989 if (index < rsv->size) {
990 rsv->entry[index].base = addr;
991 rsv->entry[index].size = size;
999 /* no slot found - allocate a new linked list entry */
1000 rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
1005 * The memremap() call above assumes that a linux_efi_memreserve entry
1006 * never crosses a page boundary, so let's ensure that this remains true
1007 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
1008 * using SZ_4K explicitly in the size calculation below.
1010 rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
1011 atomic_set(&rsv->count, 1);
1012 rsv->entry[0].base = addr;
1013 rsv->entry[0].size = size;
1015 spin_lock(&efi_mem_reserve_persistent_lock);
1016 rsv->next = efi_memreserve_root->next;
1017 efi_memreserve_root->next = __pa(rsv);
1018 spin_unlock(&efi_mem_reserve_persistent_lock);
1023 static int __init efi_memreserve_root_init(void)
1025 if (efi_memreserve_root)
1027 if (efi_memreserve_map_root())
1028 efi_memreserve_root = (void *)ULONG_MAX;
1031 early_initcall(efi_memreserve_root_init);
1034 static int update_efi_random_seed(struct notifier_block *nb,
1035 unsigned long code, void *unused)
1037 struct linux_efi_random_seed *seed;
1040 if (!kexec_in_progress)
1043 seed = memremap(efi.rng_seed, sizeof(*seed), MEMREMAP_WB);
1045 size = min(seed->size, EFI_RANDOM_SEED_SIZE);
1048 pr_err("Could not map UEFI random seed!\n");
1051 seed = memremap(efi.rng_seed, sizeof(*seed) + size,
1055 get_random_bytes(seed->bits, seed->size);
1058 pr_err("Could not map UEFI random seed!\n");
1064 static struct notifier_block efi_random_seed_nb = {
1065 .notifier_call = update_efi_random_seed,
1068 static int register_update_efi_random_seed(void)
1070 if (efi.rng_seed == EFI_INVALID_TABLE_ADDR)
1072 return register_reboot_notifier(&efi_random_seed_nb);
1074 late_initcall(register_update_efi_random_seed);