2 * efi.c - EFI subsystem
4 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
5 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
6 * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
8 * This code registers /sys/firmware/efi{,/efivars} when EFI is supported,
9 * allowing the efivarfs to be mounted or the efivars module to be loaded.
10 * The existance of /sys/firmware/efi may also be used by userspace to
11 * determine that the system supports EFI.
13 * This file is released under the GPLv2.
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/kobject.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/device.h>
22 #include <linux/efi.h>
24 #include <linux/of_fdt.h>
26 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28 #include <linux/acpi.h>
29 #include <linux/ucs2_string.h>
30 #include <linux/memblock.h>
32 #include <asm/early_ioremap.h>
34 struct efi __read_mostly efi = {
35 .mps = EFI_INVALID_TABLE_ADDR,
36 .acpi = EFI_INVALID_TABLE_ADDR,
37 .acpi20 = EFI_INVALID_TABLE_ADDR,
38 .smbios = EFI_INVALID_TABLE_ADDR,
39 .smbios3 = EFI_INVALID_TABLE_ADDR,
40 .sal_systab = EFI_INVALID_TABLE_ADDR,
41 .boot_info = EFI_INVALID_TABLE_ADDR,
42 .hcdp = EFI_INVALID_TABLE_ADDR,
43 .uga = EFI_INVALID_TABLE_ADDR,
44 .uv_systab = EFI_INVALID_TABLE_ADDR,
45 .fw_vendor = EFI_INVALID_TABLE_ADDR,
46 .runtime = EFI_INVALID_TABLE_ADDR,
47 .config_table = EFI_INVALID_TABLE_ADDR,
48 .esrt = EFI_INVALID_TABLE_ADDR,
49 .properties_table = EFI_INVALID_TABLE_ADDR,
50 .mem_attr_table = EFI_INVALID_TABLE_ADDR,
54 static bool disable_runtime;
55 static int __init setup_noefi(char *arg)
57 disable_runtime = true;
60 early_param("noefi", setup_noefi);
62 bool efi_runtime_disabled(void)
64 return disable_runtime;
67 static int __init parse_efi_cmdline(char *str)
70 pr_warn("need at least one option\n");
74 if (parse_option_str(str, "debug"))
75 set_bit(EFI_DBG, &efi.flags);
77 if (parse_option_str(str, "noruntime"))
78 disable_runtime = true;
82 early_param("efi", parse_efi_cmdline);
84 struct kobject *efi_kobj;
87 * Let's not leave out systab information that snuck into
90 static ssize_t systab_show(struct kobject *kobj,
91 struct kobj_attribute *attr, char *buf)
98 if (efi.mps != EFI_INVALID_TABLE_ADDR)
99 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
100 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
101 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
102 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
103 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
105 * If both SMBIOS and SMBIOS3 entry points are implemented, the
106 * SMBIOS3 entry point shall be preferred, so we list it first to
107 * let applications stop parsing after the first match.
109 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
110 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
111 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
112 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
113 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
114 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
115 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
116 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
117 if (efi.uga != EFI_INVALID_TABLE_ADDR)
118 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
123 static struct kobj_attribute efi_attr_systab =
124 __ATTR(systab, 0400, systab_show, NULL);
126 #define EFI_FIELD(var) efi.var
128 #define EFI_ATTR_SHOW(name) \
129 static ssize_t name##_show(struct kobject *kobj, \
130 struct kobj_attribute *attr, char *buf) \
132 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
135 EFI_ATTR_SHOW(fw_vendor);
136 EFI_ATTR_SHOW(runtime);
137 EFI_ATTR_SHOW(config_table);
139 static ssize_t fw_platform_size_show(struct kobject *kobj,
140 struct kobj_attribute *attr, char *buf)
142 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
145 static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
146 static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
147 static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
148 static struct kobj_attribute efi_attr_fw_platform_size =
149 __ATTR_RO(fw_platform_size);
151 static struct attribute *efi_subsys_attrs[] = {
152 &efi_attr_systab.attr,
153 &efi_attr_fw_vendor.attr,
154 &efi_attr_runtime.attr,
155 &efi_attr_config_table.attr,
156 &efi_attr_fw_platform_size.attr,
160 static umode_t efi_attr_is_visible(struct kobject *kobj,
161 struct attribute *attr, int n)
163 if (attr == &efi_attr_fw_vendor.attr) {
164 if (efi_enabled(EFI_PARAVIRT) ||
165 efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
167 } else if (attr == &efi_attr_runtime.attr) {
168 if (efi.runtime == EFI_INVALID_TABLE_ADDR)
170 } else if (attr == &efi_attr_config_table.attr) {
171 if (efi.config_table == EFI_INVALID_TABLE_ADDR)
178 static struct attribute_group efi_subsys_attr_group = {
179 .attrs = efi_subsys_attrs,
180 .is_visible = efi_attr_is_visible,
183 static struct efivars generic_efivars;
184 static struct efivar_operations generic_ops;
186 static int generic_ops_register(void)
188 generic_ops.get_variable = efi.get_variable;
189 generic_ops.set_variable = efi.set_variable;
190 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
191 generic_ops.get_next_variable = efi.get_next_variable;
192 generic_ops.query_variable_store = efi_query_variable_store;
194 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
197 static void generic_ops_unregister(void)
199 efivars_unregister(&generic_efivars);
202 #if IS_ENABLED(CONFIG_ACPI)
203 #define EFIVAR_SSDT_NAME_MAX 16
204 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
205 static int __init efivar_ssdt_setup(char *str)
207 if (strlen(str) < sizeof(efivar_ssdt))
208 memcpy(efivar_ssdt, str, strlen(str));
210 pr_warn("efivar_ssdt: name too long: %s\n", str);
213 __setup("efivar_ssdt=", efivar_ssdt_setup);
215 static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
216 unsigned long name_size, void *data)
218 struct efivar_entry *entry;
219 struct list_head *list = data;
220 char utf8_name[EFIVAR_SSDT_NAME_MAX];
221 int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
223 ucs2_as_utf8(utf8_name, name, limit - 1);
224 if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
227 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
231 memcpy(entry->var.VariableName, name, name_size);
232 memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
234 efivar_entry_add(entry, list);
239 static __init int efivar_ssdt_load(void)
242 struct efivar_entry *entry, *aux;
247 ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
249 list_for_each_entry_safe(entry, aux, &entries, list) {
250 pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
251 &entry->var.VendorGuid);
253 list_del(&entry->list);
255 ret = efivar_entry_size(entry, &size);
257 pr_err("failed to get var size\n");
261 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);
273 pr_err("failed to load table: %d\n", ret);
289 static inline int efivar_ssdt_load(void) { return 0; }
293 * We register the efi subsystem with the firmware subsystem and the
294 * efivars subsystem with the efi subsystem, if the system was booted with
297 static int __init efisubsys_init(void)
301 if (!efi_enabled(EFI_BOOT))
304 /* We register the efi directory at /sys/firmware/efi */
305 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
307 pr_err("efi: Firmware registration failed.\n");
311 error = generic_ops_register();
315 if (efi_enabled(EFI_RUNTIME_SERVICES))
318 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
320 pr_err("efi: Sysfs attribute export failed with error %d.\n",
325 error = efi_runtime_map_init(efi_kobj);
327 goto err_remove_group;
329 /* and the standard mountpoint for efivarfs */
330 error = sysfs_create_mount_point(efi_kobj, "efivars");
332 pr_err("efivars: Subsystem registration failed.\n");
333 goto err_remove_group;
339 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
341 generic_ops_unregister();
343 kobject_put(efi_kobj);
347 subsys_initcall(efisubsys_init);
350 * Find the efi memory descriptor for a given physical address. Given a
351 * physical address, determine if it exists within an EFI Memory Map entry,
352 * and if so, populate the supplied memory descriptor with the appropriate
355 int __init efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
357 efi_memory_desc_t *md;
359 if (!efi_enabled(EFI_MEMMAP)) {
360 pr_err_once("EFI_MEMMAP is not enabled.\n");
365 pr_err_once("out_md is null.\n");
369 for_each_efi_memory_desc(md) {
373 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
374 md->type != EFI_BOOT_SERVICES_DATA &&
375 md->type != EFI_RUNTIME_SERVICES_DATA) {
379 size = md->num_pages << EFI_PAGE_SHIFT;
380 end = md->phys_addr + size;
381 if (phys_addr >= md->phys_addr && phys_addr < end) {
382 memcpy(out_md, md, sizeof(*out_md));
386 pr_err_once("requested map not found.\n");
391 * Calculate the highest address of an efi memory descriptor.
393 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
395 u64 size = md->num_pages << EFI_PAGE_SHIFT;
396 u64 end = md->phys_addr + size;
400 void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
403 * efi_mem_reserve - Reserve an EFI memory region
404 * @addr: Physical address to reserve
405 * @size: Size of reservation
407 * Mark a region as reserved from general kernel allocation and
408 * prevent it being released by efi_free_boot_services().
410 * This function should be called drivers once they've parsed EFI
411 * configuration tables to figure out where their data lives, e.g.
414 void __init efi_mem_reserve(phys_addr_t addr, u64 size)
416 if (!memblock_is_region_reserved(addr, size))
417 memblock_reserve(addr, size);
420 * Some architectures (x86) reserve all boot services ranges
421 * until efi_free_boot_services() because of buggy firmware
422 * implementations. This means the above memblock_reserve() is
423 * superfluous on x86 and instead what it needs to do is
424 * ensure the @start, @size is not freed.
426 efi_arch_mem_reserve(addr, size);
429 static __initdata efi_config_table_type_t common_tables[] = {
430 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
431 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
432 {HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
433 {MPS_TABLE_GUID, "MPS", &efi.mps},
434 {SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
435 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
436 {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
437 {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
438 {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
439 {EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table},
440 {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table},
441 {NULL_GUID, NULL, NULL},
444 static __init int match_config_table(efi_guid_t *guid,
446 efi_config_table_type_t *table_types)
451 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
452 if (!efi_guidcmp(*guid, table_types[i].guid)) {
453 *(table_types[i].ptr) = table;
454 if (table_types[i].name)
455 pr_cont(" %s=0x%lx ",
456 table_types[i].name, table);
465 int __init efi_config_parse_tables(void *config_tables, int count, int sz,
466 efi_config_table_type_t *arch_tables)
471 tablep = config_tables;
473 for (i = 0; i < count; i++) {
477 if (efi_enabled(EFI_64BIT)) {
479 guid = ((efi_config_table_64_t *)tablep)->guid;
480 table64 = ((efi_config_table_64_t *)tablep)->table;
485 pr_err("Table located above 4GB, disabling EFI.\n");
490 guid = ((efi_config_table_32_t *)tablep)->guid;
491 table = ((efi_config_table_32_t *)tablep)->table;
494 if (!match_config_table(&guid, table, common_tables))
495 match_config_table(&guid, table, arch_tables);
500 set_bit(EFI_CONFIG_TABLES, &efi.flags);
502 /* Parse the EFI Properties table if it exists */
503 if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {
504 efi_properties_table_t *tbl;
506 tbl = early_memremap(efi.properties_table, sizeof(*tbl));
508 pr_err("Could not map Properties table!\n");
512 if (tbl->memory_protection_attribute &
513 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
514 set_bit(EFI_NX_PE_DATA, &efi.flags);
516 early_memunmap(tbl, sizeof(*tbl));
522 int __init efi_config_init(efi_config_table_type_t *arch_tables)
527 if (efi_enabled(EFI_64BIT))
528 sz = sizeof(efi_config_table_64_t);
530 sz = sizeof(efi_config_table_32_t);
533 * Let's see what config tables the firmware passed to us.
535 config_tables = early_memremap(efi.systab->tables,
536 efi.systab->nr_tables * sz);
537 if (config_tables == NULL) {
538 pr_err("Could not map Configuration table!\n");
542 ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
545 early_memunmap(config_tables, efi.systab->nr_tables * sz);
549 #ifdef CONFIG_EFI_VARS_MODULE
550 static int __init efi_load_efivars(void)
552 struct platform_device *pdev;
554 if (!efi_enabled(EFI_RUNTIME_SERVICES))
557 pdev = platform_device_register_simple("efivars", 0, NULL, 0);
558 return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
560 device_initcall(efi_load_efivars);
563 #ifdef CONFIG_EFI_PARAMS_FROM_FDT
565 #define UEFI_PARAM(name, prop, field) \
569 offsetof(struct efi_fdt_params, field), \
570 FIELD_SIZEOF(struct efi_fdt_params, field) \
575 const char propname[32];
580 static __initdata struct params fdt_params[] = {
581 UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
582 UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
583 UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
584 UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
585 UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
588 static __initdata struct params xen_fdt_params[] = {
589 UEFI_PARAM("System Table", "xen,uefi-system-table", system_table),
590 UEFI_PARAM("MemMap Address", "xen,uefi-mmap-start", mmap),
591 UEFI_PARAM("MemMap Size", "xen,uefi-mmap-size", mmap_size),
592 UEFI_PARAM("MemMap Desc. Size", "xen,uefi-mmap-desc-size", desc_size),
593 UEFI_PARAM("MemMap Desc. Version", "xen,uefi-mmap-desc-ver", desc_ver)
596 #define EFI_FDT_PARAMS_SIZE ARRAY_SIZE(fdt_params)
598 static __initdata struct {
601 struct params *params;
603 { "hypervisor", "uefi", xen_fdt_params },
604 { "chosen", NULL, fdt_params },
613 static int __init __find_uefi_params(unsigned long node,
614 struct param_info *info,
615 struct params *params)
622 for (i = 0; i < EFI_FDT_PARAMS_SIZE; i++) {
623 prop = of_get_flat_dt_prop(node, params[i].propname, &len);
625 info->missing = params[i].name;
629 dest = info->params + params[i].offset;
632 val = of_read_number(prop, len / sizeof(u32));
634 if (params[i].size == sizeof(u32))
639 if (efi_enabled(EFI_DBG))
640 pr_info(" %s: 0x%0*llx\n", params[i].name,
641 params[i].size * 2, val);
647 static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
648 int depth, void *data)
650 struct param_info *info = data;
653 for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
654 const char *subnode = dt_params[i].subnode;
656 if (depth != 1 || strcmp(uname, dt_params[i].uname) != 0) {
657 info->missing = dt_params[i].params[0].name;
662 int err = of_get_flat_dt_subnode_by_name(node, subnode);
670 return __find_uefi_params(node, info, dt_params[i].params);
676 int __init efi_get_fdt_params(struct efi_fdt_params *params)
678 struct param_info info;
681 pr_info("Getting EFI parameters from FDT:\n");
684 info.params = params;
686 ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
688 pr_info("UEFI not found.\n");
690 pr_err("Can't find '%s' in device tree!\n",
695 #endif /* CONFIG_EFI_PARAMS_FROM_FDT */
697 static __initdata char memory_type_name[][20] = {
705 "Conventional Memory",
707 "ACPI Reclaim Memory",
715 char * __init efi_md_typeattr_format(char *buf, size_t size,
716 const efi_memory_desc_t *md)
723 if (md->type >= ARRAY_SIZE(memory_type_name))
724 type_len = snprintf(pos, size, "[type=%u", md->type);
726 type_len = snprintf(pos, size, "[%-*s",
727 (int)(sizeof(memory_type_name[0]) - 1),
728 memory_type_name[md->type]);
729 if (type_len >= size)
735 attr = md->attribute;
736 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
737 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
738 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
740 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
741 snprintf(pos, size, "|attr=0x%016llx]",
742 (unsigned long long)attr);
745 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
746 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
747 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
748 attr & EFI_MEMORY_NV ? "NV" : "",
749 attr & EFI_MEMORY_XP ? "XP" : "",
750 attr & EFI_MEMORY_RP ? "RP" : "",
751 attr & EFI_MEMORY_WP ? "WP" : "",
752 attr & EFI_MEMORY_RO ? "RO" : "",
753 attr & EFI_MEMORY_UCE ? "UCE" : "",
754 attr & EFI_MEMORY_WB ? "WB" : "",
755 attr & EFI_MEMORY_WT ? "WT" : "",
756 attr & EFI_MEMORY_WC ? "WC" : "",
757 attr & EFI_MEMORY_UC ? "UC" : "");
762 * efi_mem_attributes - lookup memmap attributes for physical address
763 * @phys_addr: the physical address to lookup
765 * Search in the EFI memory map for the region covering
766 * @phys_addr. Returns the EFI memory attributes if the region
767 * was found in the memory map, 0 otherwise.
769 * Despite being marked __weak, most architectures should *not*
770 * override this function. It is __weak solely for the benefit
771 * of ia64 which has a funky EFI memory map that doesn't work
772 * the same way as other architectures.
774 u64 __weak efi_mem_attributes(unsigned long phys_addr)
776 efi_memory_desc_t *md;
778 if (!efi_enabled(EFI_MEMMAP))
781 for_each_efi_memory_desc(md) {
782 if ((md->phys_addr <= phys_addr) &&
783 (phys_addr < (md->phys_addr +
784 (md->num_pages << EFI_PAGE_SHIFT))))
785 return md->attribute;
790 int efi_status_to_err(efi_status_t status)
798 case EFI_INVALID_PARAMETER:
801 case EFI_OUT_OF_RESOURCES:
804 case EFI_DEVICE_ERROR:
807 case EFI_WRITE_PROTECTED:
810 case EFI_SECURITY_VIOLATION: