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/debugfs.h>
21 #include <linux/device.h>
22 #include <linux/efi.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 .runtime_supported_mask = EFI_RT_SUPPORTED_ALL,
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 .esrt = EFI_INVALID_TABLE_ADDR,
44 .tpm_log = EFI_INVALID_TABLE_ADDR,
45 .tpm_final_log = EFI_INVALID_TABLE_ADDR,
49 unsigned long __ro_after_init efi_rng_seed = EFI_INVALID_TABLE_ADDR;
50 static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR;
51 static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR;
53 struct mm_struct efi_mm = {
55 .mm_users = ATOMIC_INIT(2),
56 .mm_count = ATOMIC_INIT(1),
57 MMAP_LOCK_INITIALIZER(efi_mm)
58 .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
59 .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
60 .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0},
63 struct workqueue_struct *efi_rts_wq;
65 static bool disable_runtime;
66 static int __init setup_noefi(char *arg)
68 disable_runtime = true;
71 early_param("noefi", setup_noefi);
73 bool efi_runtime_disabled(void)
75 return disable_runtime;
78 bool __pure __efi_soft_reserve_enabled(void)
80 return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE);
83 static int __init parse_efi_cmdline(char *str)
86 pr_warn("need at least one option\n");
90 if (parse_option_str(str, "debug"))
91 set_bit(EFI_DBG, &efi.flags);
93 if (parse_option_str(str, "noruntime"))
94 disable_runtime = true;
96 if (parse_option_str(str, "nosoftreserve"))
97 set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags);
101 early_param("efi", parse_efi_cmdline);
103 struct kobject *efi_kobj;
106 * Let's not leave out systab information that snuck into
108 * Note, do not add more fields in systab sysfs file as it breaks sysfs
109 * one value per file rule!
111 static ssize_t systab_show(struct kobject *kobj,
112 struct kobj_attribute *attr, char *buf)
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);
133 if (IS_ENABLED(CONFIG_IA64) || IS_ENABLED(CONFIG_X86))
134 str = efi_systab_show_arch(str);
139 static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
141 static ssize_t fw_platform_size_show(struct kobject *kobj,
142 struct kobj_attribute *attr, char *buf)
144 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
147 extern __weak struct kobj_attribute efi_attr_fw_vendor;
148 extern __weak struct kobj_attribute efi_attr_runtime;
149 extern __weak struct kobj_attribute efi_attr_config_table;
150 static struct kobj_attribute efi_attr_fw_platform_size =
151 __ATTR_RO(fw_platform_size);
153 static struct attribute *efi_subsys_attrs[] = {
154 &efi_attr_systab.attr,
155 &efi_attr_fw_platform_size.attr,
156 &efi_attr_fw_vendor.attr,
157 &efi_attr_runtime.attr,
158 &efi_attr_config_table.attr,
162 umode_t __weak efi_attr_is_visible(struct kobject *kobj, struct attribute *attr,
168 static const struct attribute_group efi_subsys_attr_group = {
169 .attrs = efi_subsys_attrs,
170 .is_visible = efi_attr_is_visible,
173 static struct efivars generic_efivars;
174 static struct efivar_operations generic_ops;
176 static int generic_ops_register(void)
178 generic_ops.get_variable = efi.get_variable;
179 generic_ops.set_variable = efi.set_variable;
180 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
181 generic_ops.get_next_variable = efi.get_next_variable;
182 generic_ops.query_variable_store = efi_query_variable_store;
184 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
187 static void generic_ops_unregister(void)
189 efivars_unregister(&generic_efivars);
192 #if IS_ENABLED(CONFIG_ACPI)
193 #define EFIVAR_SSDT_NAME_MAX 16
194 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
195 static int __init efivar_ssdt_setup(char *str)
197 int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
202 if (strlen(str) < sizeof(efivar_ssdt))
203 memcpy(efivar_ssdt, str, strlen(str));
205 pr_warn("efivar_ssdt: name too long: %s\n", str);
208 __setup("efivar_ssdt=", efivar_ssdt_setup);
210 static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
211 unsigned long name_size, void *data)
213 struct efivar_entry *entry;
214 struct list_head *list = data;
215 char utf8_name[EFIVAR_SSDT_NAME_MAX];
216 int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
218 ucs2_as_utf8(utf8_name, name, limit - 1);
219 if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
222 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
226 memcpy(entry->var.VariableName, name, name_size);
227 memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
229 efivar_entry_add(entry, list);
234 static __init int efivar_ssdt_load(void)
237 struct efivar_entry *entry, *aux;
245 ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
247 list_for_each_entry_safe(entry, aux, &entries, list) {
248 pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
249 &entry->var.VendorGuid);
251 list_del(&entry->list);
253 ret = efivar_entry_size(entry, &size);
255 pr_err("failed to get var size\n");
259 data = kmalloc(size, GFP_KERNEL);
265 ret = efivar_entry_get(entry, NULL, &size, data);
267 pr_err("failed to get var data\n");
271 ret = acpi_load_table(data, NULL);
273 pr_err("failed to load table: %d\n", ret);
289 static inline int efivar_ssdt_load(void) { return 0; }
292 #ifdef CONFIG_DEBUG_FS
294 #define EFI_DEBUGFS_MAX_BLOBS 32
296 static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS];
298 static void __init efi_debugfs_init(void)
300 struct dentry *efi_debugfs;
301 efi_memory_desc_t *md;
303 int type_count[EFI_BOOT_SERVICES_DATA + 1] = {};
306 efi_debugfs = debugfs_create_dir("efi", NULL);
307 if (IS_ERR_OR_NULL(efi_debugfs))
310 for_each_efi_memory_desc(md) {
312 case EFI_BOOT_SERVICES_CODE:
313 snprintf(name, sizeof(name), "boot_services_code%d",
314 type_count[md->type]++);
316 case EFI_BOOT_SERVICES_DATA:
317 snprintf(name, sizeof(name), "boot_services_data%d",
318 type_count[md->type]++);
324 if (i >= EFI_DEBUGFS_MAX_BLOBS) {
325 pr_warn("More then %d EFI boot service segments, only showing first %d in debugfs\n",
326 EFI_DEBUGFS_MAX_BLOBS, EFI_DEBUGFS_MAX_BLOBS);
330 debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT;
331 debugfs_blob[i].data = memremap(md->phys_addr,
332 debugfs_blob[i].size,
334 if (!debugfs_blob[i].data)
337 debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]);
342 static inline void efi_debugfs_init(void) {}
346 * We register the efi subsystem with the firmware subsystem and the
347 * efivars subsystem with the efi subsystem, if the system was booted with
350 static int __init efisubsys_init(void)
354 if (!efi_enabled(EFI_RUNTIME_SERVICES))
355 efi.runtime_supported_mask = 0;
357 if (!efi_enabled(EFI_BOOT))
360 if (efi.runtime_supported_mask) {
362 * Since we process only one efi_runtime_service() at a time, an
363 * ordered workqueue (which creates only one execution context)
364 * should suffice for all our needs.
366 efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
368 pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
369 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
370 efi.runtime_supported_mask = 0;
375 if (efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES))
376 platform_device_register_simple("rtc-efi", 0, NULL, 0);
378 /* We register the efi directory at /sys/firmware/efi */
379 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
381 pr_err("efi: Firmware registration failed.\n");
385 if (efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES)) {
387 error = generic_ops_register();
390 platform_device_register_simple("efivars", 0, NULL, 0);
393 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
395 pr_err("efi: Sysfs attribute export failed with error %d.\n",
400 error = efi_runtime_map_init(efi_kobj);
402 goto err_remove_group;
404 /* and the standard mountpoint for efivarfs */
405 error = sysfs_create_mount_point(efi_kobj, "efivars");
407 pr_err("efivars: Subsystem registration failed.\n");
408 goto err_remove_group;
411 if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
417 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
419 if (efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES))
420 generic_ops_unregister();
422 kobject_put(efi_kobj);
426 subsys_initcall(efisubsys_init);
429 * Find the efi memory descriptor for a given physical address. Given a
430 * physical address, determine if it exists within an EFI Memory Map entry,
431 * and if so, populate the supplied memory descriptor with the appropriate
434 int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
436 efi_memory_desc_t *md;
438 if (!efi_enabled(EFI_MEMMAP)) {
439 pr_err_once("EFI_MEMMAP is not enabled.\n");
444 pr_err_once("out_md is null.\n");
448 for_each_efi_memory_desc(md) {
452 size = md->num_pages << EFI_PAGE_SHIFT;
453 end = md->phys_addr + size;
454 if (phys_addr >= md->phys_addr && phys_addr < end) {
455 memcpy(out_md, md, sizeof(*out_md));
463 * Calculate the highest address of an efi memory descriptor.
465 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
467 u64 size = md->num_pages << EFI_PAGE_SHIFT;
468 u64 end = md->phys_addr + size;
472 void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
475 * efi_mem_reserve - Reserve an EFI memory region
476 * @addr: Physical address to reserve
477 * @size: Size of reservation
479 * Mark a region as reserved from general kernel allocation and
480 * prevent it being released by efi_free_boot_services().
482 * This function should be called drivers once they've parsed EFI
483 * configuration tables to figure out where their data lives, e.g.
486 void __init efi_mem_reserve(phys_addr_t addr, u64 size)
488 if (!memblock_is_region_reserved(addr, size))
489 memblock_reserve(addr, size);
492 * Some architectures (x86) reserve all boot services ranges
493 * until efi_free_boot_services() because of buggy firmware
494 * implementations. This means the above memblock_reserve() is
495 * superfluous on x86 and instead what it needs to do is
496 * ensure the @start, @size is not freed.
498 efi_arch_mem_reserve(addr, size);
501 static const efi_config_table_type_t common_tables[] __initconst = {
502 {ACPI_20_TABLE_GUID, &efi.acpi20, "ACPI 2.0" },
503 {ACPI_TABLE_GUID, &efi.acpi, "ACPI" },
504 {SMBIOS_TABLE_GUID, &efi.smbios, "SMBIOS" },
505 {SMBIOS3_TABLE_GUID, &efi.smbios3, "SMBIOS 3.0" },
506 {EFI_SYSTEM_RESOURCE_TABLE_GUID, &efi.esrt, "ESRT" },
507 {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, &efi_mem_attr_table, "MEMATTR" },
508 {LINUX_EFI_RANDOM_SEED_TABLE_GUID, &efi_rng_seed, "RNG" },
509 {LINUX_EFI_TPM_EVENT_LOG_GUID, &efi.tpm_log, "TPMEventLog" },
510 {LINUX_EFI_TPM_FINAL_LOG_GUID, &efi.tpm_final_log, "TPMFinalLog" },
511 {LINUX_EFI_MEMRESERVE_TABLE_GUID, &mem_reserve, "MEMRESERVE" },
512 {EFI_RT_PROPERTIES_TABLE_GUID, &rt_prop, "RTPROP" },
513 #ifdef CONFIG_EFI_RCI2_TABLE
514 {DELLEMC_EFI_RCI2_TABLE_GUID, &rci2_table_phys },
519 static __init int match_config_table(const efi_guid_t *guid,
521 const efi_config_table_type_t *table_types)
525 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
526 if (!efi_guidcmp(*guid, table_types[i].guid)) {
527 *(table_types[i].ptr) = table;
528 if (table_types[i].name[0])
530 table_types[i].name, table);
538 int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
540 const efi_config_table_type_t *arch_tables)
542 const efi_config_table_64_t *tbl64 = (void *)config_tables;
543 const efi_config_table_32_t *tbl32 = (void *)config_tables;
544 const efi_guid_t *guid;
549 for (i = 0; i < count; i++) {
550 if (!IS_ENABLED(CONFIG_X86)) {
551 guid = &config_tables[i].guid;
552 table = (unsigned long)config_tables[i].table;
553 } else if (efi_enabled(EFI_64BIT)) {
554 guid = &tbl64[i].guid;
555 table = tbl64[i].table;
557 if (IS_ENABLED(CONFIG_X86_32) &&
558 tbl64[i].table > U32_MAX) {
560 pr_err("Table located above 4GB, disabling EFI.\n");
564 guid = &tbl32[i].guid;
565 table = tbl32[i].table;
568 if (!match_config_table(guid, table, common_tables) && arch_tables)
569 match_config_table(guid, table, arch_tables);
572 set_bit(EFI_CONFIG_TABLES, &efi.flags);
574 if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) {
575 struct linux_efi_random_seed *seed;
578 seed = early_memremap(efi_rng_seed, sizeof(*seed));
580 size = READ_ONCE(seed->size);
581 early_memunmap(seed, sizeof(*seed));
583 pr_err("Could not map UEFI random seed!\n");
586 seed = early_memremap(efi_rng_seed,
587 sizeof(*seed) + size);
589 pr_notice("seeding entropy pool\n");
590 add_bootloader_randomness(seed->bits, size);
591 early_memunmap(seed, sizeof(*seed) + size);
593 pr_err("Could not map UEFI random seed!\n");
598 if (!IS_ENABLED(CONFIG_X86_32) && efi_enabled(EFI_MEMMAP))
601 efi_tpm_eventlog_init();
603 if (mem_reserve != EFI_INVALID_TABLE_ADDR) {
604 unsigned long prsv = mem_reserve;
607 struct linux_efi_memreserve *rsv;
611 * Just map a full page: that is what we will get
612 * anyway, and it permits us to map the entire entry
613 * before knowing its size.
615 p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
618 pr_err("Could not map UEFI memreserve entry!\n");
622 rsv = (void *)(p + prsv % PAGE_SIZE);
624 /* reserve the entry itself */
625 memblock_reserve(prsv, EFI_MEMRESERVE_SIZE(rsv->size));
627 for (i = 0; i < atomic_read(&rsv->count); i++) {
628 memblock_reserve(rsv->entry[i].base,
633 early_memunmap(p, PAGE_SIZE);
637 if (rt_prop != EFI_INVALID_TABLE_ADDR) {
638 efi_rt_properties_table_t *tbl;
640 tbl = early_memremap(rt_prop, sizeof(*tbl));
642 efi.runtime_supported_mask &= tbl->runtime_services_supported;
643 early_memunmap(tbl, sizeof(*tbl));
650 int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr,
651 int min_major_version)
653 if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) {
654 pr_err("System table signature incorrect!\n");
658 if ((systab_hdr->revision >> 16) < min_major_version)
659 pr_err("Warning: System table version %d.%02d, expected %d.00 or greater!\n",
660 systab_hdr->revision >> 16,
661 systab_hdr->revision & 0xffff,
668 static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor,
671 const efi_char16_t *ret;
673 ret = early_memremap_ro(fw_vendor, size);
675 pr_err("Could not map the firmware vendor!\n");
679 static void __init unmap_fw_vendor(const void *fw_vendor, size_t size)
681 early_memunmap((void *)fw_vendor, size);
684 #define map_fw_vendor(p, s) __va(p)
685 #define unmap_fw_vendor(v, s)
688 void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
689 unsigned long fw_vendor)
691 char vendor[100] = "unknown";
692 const efi_char16_t *c16;
695 c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t));
697 for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
701 unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t));
704 pr_info("EFI v%u.%.02u by %s\n",
705 systab_hdr->revision >> 16,
706 systab_hdr->revision & 0xffff,
710 static __initdata char memory_type_name[][20] = {
718 "Conventional Memory",
720 "ACPI Reclaim Memory",
728 char * __init efi_md_typeattr_format(char *buf, size_t size,
729 const efi_memory_desc_t *md)
736 if (md->type >= ARRAY_SIZE(memory_type_name))
737 type_len = snprintf(pos, size, "[type=%u", md->type);
739 type_len = snprintf(pos, size, "[%-*s",
740 (int)(sizeof(memory_type_name[0]) - 1),
741 memory_type_name[md->type]);
742 if (type_len >= size)
748 attr = md->attribute;
749 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
750 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
751 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
752 EFI_MEMORY_NV | EFI_MEMORY_SP |
753 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
754 snprintf(pos, size, "|attr=0x%016llx]",
755 (unsigned long long)attr);
758 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
759 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
760 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
761 attr & EFI_MEMORY_SP ? "SP" : "",
762 attr & EFI_MEMORY_NV ? "NV" : "",
763 attr & EFI_MEMORY_XP ? "XP" : "",
764 attr & EFI_MEMORY_RP ? "RP" : "",
765 attr & EFI_MEMORY_WP ? "WP" : "",
766 attr & EFI_MEMORY_RO ? "RO" : "",
767 attr & EFI_MEMORY_UCE ? "UCE" : "",
768 attr & EFI_MEMORY_WB ? "WB" : "",
769 attr & EFI_MEMORY_WT ? "WT" : "",
770 attr & EFI_MEMORY_WC ? "WC" : "",
771 attr & EFI_MEMORY_UC ? "UC" : "");
776 * IA64 has a funky EFI memory map that doesn't work the same way as
777 * other architectures.
781 * efi_mem_attributes - lookup memmap attributes for physical address
782 * @phys_addr: the physical address to lookup
784 * Search in the EFI memory map for the region covering
785 * @phys_addr. Returns the EFI memory attributes if the region
786 * was found in the memory map, 0 otherwise.
788 u64 efi_mem_attributes(unsigned long phys_addr)
790 efi_memory_desc_t *md;
792 if (!efi_enabled(EFI_MEMMAP))
795 for_each_efi_memory_desc(md) {
796 if ((md->phys_addr <= phys_addr) &&
797 (phys_addr < (md->phys_addr +
798 (md->num_pages << EFI_PAGE_SHIFT))))
799 return md->attribute;
805 * efi_mem_type - lookup memmap type for physical address
806 * @phys_addr: the physical address to lookup
808 * Search in the EFI memory map for the region covering @phys_addr.
809 * Returns the EFI memory type if the region was found in the memory
810 * map, -EINVAL otherwise.
812 int efi_mem_type(unsigned long phys_addr)
814 const efi_memory_desc_t *md;
816 if (!efi_enabled(EFI_MEMMAP))
819 for_each_efi_memory_desc(md) {
820 if ((md->phys_addr <= phys_addr) &&
821 (phys_addr < (md->phys_addr +
822 (md->num_pages << EFI_PAGE_SHIFT))))
829 int efi_status_to_err(efi_status_t status)
837 case EFI_INVALID_PARAMETER:
840 case EFI_OUT_OF_RESOURCES:
843 case EFI_DEVICE_ERROR:
846 case EFI_WRITE_PROTECTED:
849 case EFI_SECURITY_VIOLATION:
865 static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
866 static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
868 static int __init efi_memreserve_map_root(void)
870 if (mem_reserve == EFI_INVALID_TABLE_ADDR)
873 efi_memreserve_root = memremap(mem_reserve,
874 sizeof(*efi_memreserve_root),
876 if (WARN_ON_ONCE(!efi_memreserve_root))
881 static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size)
883 struct resource *res, *parent;
885 res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
889 res->name = "reserved";
890 res->flags = IORESOURCE_MEM;
892 res->end = addr + size - 1;
894 /* we expect a conflict with a 'System RAM' region */
895 parent = request_resource_conflict(&iomem_resource, res);
896 return parent ? request_resource(parent, res) : 0;
899 int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
901 struct linux_efi_memreserve *rsv;
905 if (efi_memreserve_root == (void *)ULONG_MAX)
908 if (!efi_memreserve_root) {
909 rc = efi_memreserve_map_root();
914 /* first try to find a slot in an existing linked list entry */
915 for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
916 rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
917 index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
918 if (index < rsv->size) {
919 rsv->entry[index].base = addr;
920 rsv->entry[index].size = size;
923 return efi_mem_reserve_iomem(addr, size);
928 /* no slot found - allocate a new linked list entry */
929 rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
933 rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K);
935 free_page((unsigned long)rsv);
940 * The memremap() call above assumes that a linux_efi_memreserve entry
941 * never crosses a page boundary, so let's ensure that this remains true
942 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
943 * using SZ_4K explicitly in the size calculation below.
945 rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
946 atomic_set(&rsv->count, 1);
947 rsv->entry[0].base = addr;
948 rsv->entry[0].size = size;
950 spin_lock(&efi_mem_reserve_persistent_lock);
951 rsv->next = efi_memreserve_root->next;
952 efi_memreserve_root->next = __pa(rsv);
953 spin_unlock(&efi_mem_reserve_persistent_lock);
955 return efi_mem_reserve_iomem(addr, size);
958 static int __init efi_memreserve_root_init(void)
960 if (efi_memreserve_root)
962 if (efi_memreserve_map_root())
963 efi_memreserve_root = (void *)ULONG_MAX;
966 early_initcall(efi_memreserve_root_init);
969 static int update_efi_random_seed(struct notifier_block *nb,
970 unsigned long code, void *unused)
972 struct linux_efi_random_seed *seed;
975 if (!kexec_in_progress)
978 seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB);
980 size = min(seed->size, EFI_RANDOM_SEED_SIZE);
983 pr_err("Could not map UEFI random seed!\n");
986 seed = memremap(efi_rng_seed, sizeof(*seed) + size,
990 get_random_bytes(seed->bits, seed->size);
993 pr_err("Could not map UEFI random seed!\n");
999 static struct notifier_block efi_random_seed_nb = {
1000 .notifier_call = update_efi_random_seed,
1003 static int __init register_update_efi_random_seed(void)
1005 if (efi_rng_seed == EFI_INVALID_TABLE_ADDR)
1007 return register_reboot_notifier(&efi_random_seed_nb);
1009 late_initcall(register_update_efi_random_seed);