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_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
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 extern char *efi_systab_show_arch(char *str);
136 str = efi_systab_show_arch(str);
142 static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
144 static ssize_t fw_platform_size_show(struct kobject *kobj,
145 struct kobj_attribute *attr, char *buf)
147 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
150 extern __weak struct kobj_attribute efi_attr_fw_vendor;
151 extern __weak struct kobj_attribute efi_attr_runtime;
152 extern __weak struct kobj_attribute efi_attr_config_table;
153 static struct kobj_attribute efi_attr_fw_platform_size =
154 __ATTR_RO(fw_platform_size);
156 static struct attribute *efi_subsys_attrs[] = {
157 &efi_attr_systab.attr,
158 &efi_attr_fw_platform_size.attr,
159 &efi_attr_fw_vendor.attr,
160 &efi_attr_runtime.attr,
161 &efi_attr_config_table.attr,
165 umode_t __weak efi_attr_is_visible(struct kobject *kobj, struct attribute *attr,
171 static const struct attribute_group efi_subsys_attr_group = {
172 .attrs = efi_subsys_attrs,
173 .is_visible = efi_attr_is_visible,
176 static struct efivars generic_efivars;
177 static struct efivar_operations generic_ops;
179 static int generic_ops_register(void)
181 generic_ops.get_variable = efi.get_variable;
182 generic_ops.set_variable = efi.set_variable;
183 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
184 generic_ops.get_next_variable = efi.get_next_variable;
185 generic_ops.query_variable_store = efi_query_variable_store;
187 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
190 static void generic_ops_unregister(void)
192 efivars_unregister(&generic_efivars);
195 #if IS_ENABLED(CONFIG_ACPI)
196 #define EFIVAR_SSDT_NAME_MAX 16
197 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
198 static int __init efivar_ssdt_setup(char *str)
200 int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
205 if (strlen(str) < sizeof(efivar_ssdt))
206 memcpy(efivar_ssdt, str, strlen(str));
208 pr_warn("efivar_ssdt: name too long: %s\n", str);
211 __setup("efivar_ssdt=", efivar_ssdt_setup);
213 static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
214 unsigned long name_size, void *data)
216 struct efivar_entry *entry;
217 struct list_head *list = data;
218 char utf8_name[EFIVAR_SSDT_NAME_MAX];
219 int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
221 ucs2_as_utf8(utf8_name, name, limit - 1);
222 if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
225 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
229 memcpy(entry->var.VariableName, name, name_size);
230 memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
232 efivar_entry_add(entry, list);
237 static __init int efivar_ssdt_load(void)
240 struct efivar_entry *entry, *aux;
248 ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
250 list_for_each_entry_safe(entry, aux, &entries, list) {
251 pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
252 &entry->var.VendorGuid);
254 list_del(&entry->list);
256 ret = efivar_entry_size(entry, &size);
258 pr_err("failed to get var size\n");
262 data = kmalloc(size, GFP_KERNEL);
268 ret = efivar_entry_get(entry, NULL, &size, data);
270 pr_err("failed to get var data\n");
274 ret = acpi_load_table(data, NULL);
276 pr_err("failed to load table: %d\n", ret);
292 static inline int efivar_ssdt_load(void) { return 0; }
295 #ifdef CONFIG_DEBUG_FS
297 #define EFI_DEBUGFS_MAX_BLOBS 32
299 static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS];
301 static void __init efi_debugfs_init(void)
303 struct dentry *efi_debugfs;
304 efi_memory_desc_t *md;
306 int type_count[EFI_BOOT_SERVICES_DATA + 1] = {};
309 efi_debugfs = debugfs_create_dir("efi", NULL);
310 if (IS_ERR_OR_NULL(efi_debugfs))
313 for_each_efi_memory_desc(md) {
315 case EFI_BOOT_SERVICES_CODE:
316 snprintf(name, sizeof(name), "boot_services_code%d",
317 type_count[md->type]++);
319 case EFI_BOOT_SERVICES_DATA:
320 snprintf(name, sizeof(name), "boot_services_data%d",
321 type_count[md->type]++);
327 if (i >= EFI_DEBUGFS_MAX_BLOBS) {
328 pr_warn("More then %d EFI boot service segments, only showing first %d in debugfs\n",
329 EFI_DEBUGFS_MAX_BLOBS, EFI_DEBUGFS_MAX_BLOBS);
333 debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT;
334 debugfs_blob[i].data = memremap(md->phys_addr,
335 debugfs_blob[i].size,
337 if (!debugfs_blob[i].data)
340 debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]);
345 static inline void efi_debugfs_init(void) {}
349 * We register the efi subsystem with the firmware subsystem and the
350 * efivars subsystem with the efi subsystem, if the system was booted with
353 static int __init efisubsys_init(void)
357 if (!efi_enabled(EFI_RUNTIME_SERVICES))
358 efi.runtime_supported_mask = 0;
360 if (!efi_enabled(EFI_BOOT))
363 if (efi.runtime_supported_mask) {
365 * Since we process only one efi_runtime_service() at a time, an
366 * ordered workqueue (which creates only one execution context)
367 * should suffice for all our needs.
369 efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
371 pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
372 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
373 efi.runtime_supported_mask = 0;
378 if (efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES))
379 platform_device_register_simple("rtc-efi", 0, NULL, 0);
381 /* We register the efi directory at /sys/firmware/efi */
382 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
384 pr_err("efi: Firmware registration failed.\n");
388 if (efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES)) {
390 error = generic_ops_register();
393 platform_device_register_simple("efivars", 0, NULL, 0);
396 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
398 pr_err("efi: Sysfs attribute export failed with error %d.\n",
403 error = efi_runtime_map_init(efi_kobj);
405 goto err_remove_group;
407 /* and the standard mountpoint for efivarfs */
408 error = sysfs_create_mount_point(efi_kobj, "efivars");
410 pr_err("efivars: Subsystem registration failed.\n");
411 goto err_remove_group;
414 if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
420 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
422 if (efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES))
423 generic_ops_unregister();
425 kobject_put(efi_kobj);
429 subsys_initcall(efisubsys_init);
432 * Find the efi memory descriptor for a given physical address. Given a
433 * physical address, determine if it exists within an EFI Memory Map entry,
434 * and if so, populate the supplied memory descriptor with the appropriate
437 int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
439 efi_memory_desc_t *md;
441 if (!efi_enabled(EFI_MEMMAP)) {
442 pr_err_once("EFI_MEMMAP is not enabled.\n");
447 pr_err_once("out_md is null.\n");
451 for_each_efi_memory_desc(md) {
455 size = md->num_pages << EFI_PAGE_SHIFT;
456 end = md->phys_addr + size;
457 if (phys_addr >= md->phys_addr && phys_addr < end) {
458 memcpy(out_md, md, sizeof(*out_md));
466 * Calculate the highest address of an efi memory descriptor.
468 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
470 u64 size = md->num_pages << EFI_PAGE_SHIFT;
471 u64 end = md->phys_addr + size;
475 void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
478 * efi_mem_reserve - Reserve an EFI memory region
479 * @addr: Physical address to reserve
480 * @size: Size of reservation
482 * Mark a region as reserved from general kernel allocation and
483 * prevent it being released by efi_free_boot_services().
485 * This function should be called drivers once they've parsed EFI
486 * configuration tables to figure out where their data lives, e.g.
489 void __init efi_mem_reserve(phys_addr_t addr, u64 size)
491 if (!memblock_is_region_reserved(addr, size))
492 memblock_reserve(addr, size);
495 * Some architectures (x86) reserve all boot services ranges
496 * until efi_free_boot_services() because of buggy firmware
497 * implementations. This means the above memblock_reserve() is
498 * superfluous on x86 and instead what it needs to do is
499 * ensure the @start, @size is not freed.
501 efi_arch_mem_reserve(addr, size);
504 static const efi_config_table_type_t common_tables[] __initconst = {
505 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
506 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
507 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
508 {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
509 {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
510 {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi_mem_attr_table},
511 {LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi_rng_seed},
512 {LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log},
513 {LINUX_EFI_TPM_FINAL_LOG_GUID, "TPMFinalLog", &efi.tpm_final_log},
514 {LINUX_EFI_MEMRESERVE_TABLE_GUID, "MEMRESERVE", &mem_reserve},
515 {EFI_RT_PROPERTIES_TABLE_GUID, "RTPROP", &rt_prop},
516 #ifdef CONFIG_EFI_RCI2_TABLE
517 {DELLEMC_EFI_RCI2_TABLE_GUID, NULL, &rci2_table_phys},
519 {NULL_GUID, NULL, NULL},
522 static __init int match_config_table(const efi_guid_t *guid,
524 const efi_config_table_type_t *table_types)
529 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
530 if (!efi_guidcmp(*guid, table_types[i].guid)) {
531 *(table_types[i].ptr) = table;
532 if (table_types[i].name)
533 pr_cont(" %s=0x%lx ",
534 table_types[i].name, table);
543 int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
545 const efi_config_table_type_t *arch_tables)
547 const efi_config_table_64_t *tbl64 = (void *)config_tables;
548 const efi_config_table_32_t *tbl32 = (void *)config_tables;
549 const efi_guid_t *guid;
554 for (i = 0; i < count; i++) {
555 if (!IS_ENABLED(CONFIG_X86)) {
556 guid = &config_tables[i].guid;
557 table = (unsigned long)config_tables[i].table;
558 } else if (efi_enabled(EFI_64BIT)) {
559 guid = &tbl64[i].guid;
560 table = tbl64[i].table;
562 if (IS_ENABLED(CONFIG_X86_32) &&
563 tbl64[i].table > U32_MAX) {
565 pr_err("Table located above 4GB, disabling EFI.\n");
569 guid = &tbl32[i].guid;
570 table = tbl32[i].table;
573 if (!match_config_table(guid, table, common_tables))
574 match_config_table(guid, table, arch_tables);
577 set_bit(EFI_CONFIG_TABLES, &efi.flags);
579 if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) {
580 struct linux_efi_random_seed *seed;
583 seed = early_memremap(efi_rng_seed, sizeof(*seed));
586 early_memunmap(seed, sizeof(*seed));
588 pr_err("Could not map UEFI random seed!\n");
591 seed = early_memremap(efi_rng_seed,
592 sizeof(*seed) + size);
594 pr_notice("seeding entropy pool\n");
595 add_bootloader_randomness(seed->bits, seed->size);
596 early_memunmap(seed, sizeof(*seed) + size);
598 pr_err("Could not map UEFI random seed!\n");
603 if (efi_enabled(EFI_MEMMAP))
606 efi_tpm_eventlog_init();
608 if (mem_reserve != EFI_INVALID_TABLE_ADDR) {
609 unsigned long prsv = mem_reserve;
612 struct linux_efi_memreserve *rsv;
616 * Just map a full page: that is what we will get
617 * anyway, and it permits us to map the entire entry
618 * before knowing its size.
620 p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
623 pr_err("Could not map UEFI memreserve entry!\n");
627 rsv = (void *)(p + prsv % PAGE_SIZE);
629 /* reserve the entry itself */
630 memblock_reserve(prsv, EFI_MEMRESERVE_SIZE(rsv->size));
632 for (i = 0; i < atomic_read(&rsv->count); i++) {
633 memblock_reserve(rsv->entry[i].base,
638 early_memunmap(p, PAGE_SIZE);
642 if (rt_prop != EFI_INVALID_TABLE_ADDR) {
643 efi_rt_properties_table_t *tbl;
645 tbl = early_memremap(rt_prop, sizeof(*tbl));
647 efi.runtime_supported_mask &= tbl->runtime_services_supported;
648 early_memunmap(tbl, sizeof(*tbl));
655 int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr,
656 int min_major_version)
658 if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) {
659 pr_err("System table signature incorrect!\n");
663 if ((systab_hdr->revision >> 16) < min_major_version)
664 pr_err("Warning: System table version %d.%02d, expected %d.00 or greater!\n",
665 systab_hdr->revision >> 16,
666 systab_hdr->revision & 0xffff,
673 static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor,
676 const efi_char16_t *ret;
678 ret = early_memremap_ro(fw_vendor, size);
680 pr_err("Could not map the firmware vendor!\n");
684 static void __init unmap_fw_vendor(const void *fw_vendor, size_t size)
686 early_memunmap((void *)fw_vendor, size);
689 #define map_fw_vendor(p, s) __va(p)
690 #define unmap_fw_vendor(v, s)
693 void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
694 unsigned long fw_vendor)
696 char vendor[100] = "unknown";
697 const efi_char16_t *c16;
700 c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t));
702 for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
706 unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t));
709 pr_info("EFI v%u.%.02u by %s\n",
710 systab_hdr->revision >> 16,
711 systab_hdr->revision & 0xffff,
715 static __initdata char memory_type_name[][20] = {
723 "Conventional Memory",
725 "ACPI Reclaim Memory",
733 char * __init efi_md_typeattr_format(char *buf, size_t size,
734 const efi_memory_desc_t *md)
741 if (md->type >= ARRAY_SIZE(memory_type_name))
742 type_len = snprintf(pos, size, "[type=%u", md->type);
744 type_len = snprintf(pos, size, "[%-*s",
745 (int)(sizeof(memory_type_name[0]) - 1),
746 memory_type_name[md->type]);
747 if (type_len >= size)
753 attr = md->attribute;
754 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
755 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
756 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
757 EFI_MEMORY_NV | EFI_MEMORY_SP |
758 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
759 snprintf(pos, size, "|attr=0x%016llx]",
760 (unsigned long long)attr);
763 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
764 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
765 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
766 attr & EFI_MEMORY_SP ? "SP" : "",
767 attr & EFI_MEMORY_NV ? "NV" : "",
768 attr & EFI_MEMORY_XP ? "XP" : "",
769 attr & EFI_MEMORY_RP ? "RP" : "",
770 attr & EFI_MEMORY_WP ? "WP" : "",
771 attr & EFI_MEMORY_RO ? "RO" : "",
772 attr & EFI_MEMORY_UCE ? "UCE" : "",
773 attr & EFI_MEMORY_WB ? "WB" : "",
774 attr & EFI_MEMORY_WT ? "WT" : "",
775 attr & EFI_MEMORY_WC ? "WC" : "",
776 attr & EFI_MEMORY_UC ? "UC" : "");
781 * IA64 has a funky EFI memory map that doesn't work the same way as
782 * other architectures.
786 * efi_mem_attributes - lookup memmap attributes for physical address
787 * @phys_addr: the physical address to lookup
789 * Search in the EFI memory map for the region covering
790 * @phys_addr. Returns the EFI memory attributes if the region
791 * was found in the memory map, 0 otherwise.
793 u64 efi_mem_attributes(unsigned long phys_addr)
795 efi_memory_desc_t *md;
797 if (!efi_enabled(EFI_MEMMAP))
800 for_each_efi_memory_desc(md) {
801 if ((md->phys_addr <= phys_addr) &&
802 (phys_addr < (md->phys_addr +
803 (md->num_pages << EFI_PAGE_SHIFT))))
804 return md->attribute;
810 * efi_mem_type - lookup memmap type for physical address
811 * @phys_addr: the physical address to lookup
813 * Search in the EFI memory map for the region covering @phys_addr.
814 * Returns the EFI memory type if the region was found in the memory
815 * map, -EINVAL otherwise.
817 int efi_mem_type(unsigned long phys_addr)
819 const efi_memory_desc_t *md;
821 if (!efi_enabled(EFI_MEMMAP))
824 for_each_efi_memory_desc(md) {
825 if ((md->phys_addr <= phys_addr) &&
826 (phys_addr < (md->phys_addr +
827 (md->num_pages << EFI_PAGE_SHIFT))))
834 int efi_status_to_err(efi_status_t status)
842 case EFI_INVALID_PARAMETER:
845 case EFI_OUT_OF_RESOURCES:
848 case EFI_DEVICE_ERROR:
851 case EFI_WRITE_PROTECTED:
854 case EFI_SECURITY_VIOLATION:
870 static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
871 static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
873 static int __init efi_memreserve_map_root(void)
875 if (mem_reserve == EFI_INVALID_TABLE_ADDR)
878 efi_memreserve_root = memremap(mem_reserve,
879 sizeof(*efi_memreserve_root),
881 if (WARN_ON_ONCE(!efi_memreserve_root))
886 static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size)
888 struct resource *res, *parent;
890 res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
894 res->name = "reserved";
895 res->flags = IORESOURCE_MEM;
897 res->end = addr + size - 1;
899 /* we expect a conflict with a 'System RAM' region */
900 parent = request_resource_conflict(&iomem_resource, res);
901 return parent ? request_resource(parent, res) : 0;
904 int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
906 struct linux_efi_memreserve *rsv;
910 if (efi_memreserve_root == (void *)ULONG_MAX)
913 if (!efi_memreserve_root) {
914 rc = efi_memreserve_map_root();
919 /* first try to find a slot in an existing linked list entry */
920 for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
921 rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
922 index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
923 if (index < rsv->size) {
924 rsv->entry[index].base = addr;
925 rsv->entry[index].size = size;
928 return efi_mem_reserve_iomem(addr, size);
933 /* no slot found - allocate a new linked list entry */
934 rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
938 rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K);
940 free_page((unsigned long)rsv);
945 * The memremap() call above assumes that a linux_efi_memreserve entry
946 * never crosses a page boundary, so let's ensure that this remains true
947 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
948 * using SZ_4K explicitly in the size calculation below.
950 rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
951 atomic_set(&rsv->count, 1);
952 rsv->entry[0].base = addr;
953 rsv->entry[0].size = size;
955 spin_lock(&efi_mem_reserve_persistent_lock);
956 rsv->next = efi_memreserve_root->next;
957 efi_memreserve_root->next = __pa(rsv);
958 spin_unlock(&efi_mem_reserve_persistent_lock);
960 return efi_mem_reserve_iomem(addr, size);
963 static int __init efi_memreserve_root_init(void)
965 if (efi_memreserve_root)
967 if (efi_memreserve_map_root())
968 efi_memreserve_root = (void *)ULONG_MAX;
971 early_initcall(efi_memreserve_root_init);
974 static int update_efi_random_seed(struct notifier_block *nb,
975 unsigned long code, void *unused)
977 struct linux_efi_random_seed *seed;
980 if (!kexec_in_progress)
983 seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB);
985 size = min(seed->size, EFI_RANDOM_SEED_SIZE);
988 pr_err("Could not map UEFI random seed!\n");
991 seed = memremap(efi_rng_seed, sizeof(*seed) + size,
995 get_random_bytes(seed->bits, seed->size);
998 pr_err("Could not map UEFI random seed!\n");
1004 static struct notifier_block efi_random_seed_nb = {
1005 .notifier_call = update_efi_random_seed,
1008 static int __init register_update_efi_random_seed(void)
1010 if (efi_rng_seed == EFI_INVALID_TABLE_ADDR)
1012 return register_reboot_notifier(&efi_random_seed_nb);
1014 late_initcall(register_update_efi_random_seed);