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>
28 struct efi __read_mostly efi = {
29 .mps = EFI_INVALID_TABLE_ADDR,
30 .acpi = EFI_INVALID_TABLE_ADDR,
31 .acpi20 = EFI_INVALID_TABLE_ADDR,
32 .smbios = EFI_INVALID_TABLE_ADDR,
33 .smbios3 = EFI_INVALID_TABLE_ADDR,
34 .sal_systab = EFI_INVALID_TABLE_ADDR,
35 .boot_info = EFI_INVALID_TABLE_ADDR,
36 .hcdp = EFI_INVALID_TABLE_ADDR,
37 .uga = EFI_INVALID_TABLE_ADDR,
38 .uv_systab = EFI_INVALID_TABLE_ADDR,
39 .fw_vendor = EFI_INVALID_TABLE_ADDR,
40 .runtime = EFI_INVALID_TABLE_ADDR,
41 .config_table = EFI_INVALID_TABLE_ADDR,
42 .esrt = EFI_INVALID_TABLE_ADDR,
46 static bool disable_runtime;
47 static int __init setup_noefi(char *arg)
49 disable_runtime = true;
52 early_param("noefi", setup_noefi);
54 bool efi_runtime_disabled(void)
56 return disable_runtime;
59 static int __init parse_efi_cmdline(char *str)
62 pr_warn("need at least one option\n");
66 if (parse_option_str(str, "noruntime"))
67 disable_runtime = true;
71 early_param("efi", parse_efi_cmdline);
73 struct kobject *efi_kobj;
76 * Let's not leave out systab information that snuck into
79 static ssize_t systab_show(struct kobject *kobj,
80 struct kobj_attribute *attr, char *buf)
87 if (efi.mps != EFI_INVALID_TABLE_ADDR)
88 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
89 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
90 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
91 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
92 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
94 * If both SMBIOS and SMBIOS3 entry points are implemented, the
95 * SMBIOS3 entry point shall be preferred, so we list it first to
96 * let applications stop parsing after the first match.
98 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
99 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
100 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
101 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
102 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
103 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
104 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
105 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
106 if (efi.uga != EFI_INVALID_TABLE_ADDR)
107 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
112 static struct kobj_attribute efi_attr_systab =
113 __ATTR(systab, 0400, systab_show, NULL);
115 #define EFI_FIELD(var) efi.var
117 #define EFI_ATTR_SHOW(name) \
118 static ssize_t name##_show(struct kobject *kobj, \
119 struct kobj_attribute *attr, char *buf) \
121 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
124 EFI_ATTR_SHOW(fw_vendor);
125 EFI_ATTR_SHOW(runtime);
126 EFI_ATTR_SHOW(config_table);
128 static ssize_t fw_platform_size_show(struct kobject *kobj,
129 struct kobj_attribute *attr, char *buf)
131 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
134 static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
135 static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
136 static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
137 static struct kobj_attribute efi_attr_fw_platform_size =
138 __ATTR_RO(fw_platform_size);
140 static struct attribute *efi_subsys_attrs[] = {
141 &efi_attr_systab.attr,
142 &efi_attr_fw_vendor.attr,
143 &efi_attr_runtime.attr,
144 &efi_attr_config_table.attr,
145 &efi_attr_fw_platform_size.attr,
149 static umode_t efi_attr_is_visible(struct kobject *kobj,
150 struct attribute *attr, int n)
152 if (attr == &efi_attr_fw_vendor.attr) {
153 if (efi_enabled(EFI_PARAVIRT) ||
154 efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
156 } else if (attr == &efi_attr_runtime.attr) {
157 if (efi.runtime == EFI_INVALID_TABLE_ADDR)
159 } else if (attr == &efi_attr_config_table.attr) {
160 if (efi.config_table == EFI_INVALID_TABLE_ADDR)
167 static struct attribute_group efi_subsys_attr_group = {
168 .attrs = efi_subsys_attrs,
169 .is_visible = efi_attr_is_visible,
172 static struct efivars generic_efivars;
173 static struct efivar_operations generic_ops;
175 static int generic_ops_register(void)
177 generic_ops.get_variable = efi.get_variable;
178 generic_ops.set_variable = efi.set_variable;
179 generic_ops.get_next_variable = efi.get_next_variable;
180 generic_ops.query_variable_store = efi_query_variable_store;
182 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
185 static void generic_ops_unregister(void)
187 efivars_unregister(&generic_efivars);
191 * We register the efi subsystem with the firmware subsystem and the
192 * efivars subsystem with the efi subsystem, if the system was booted with
195 static int __init efisubsys_init(void)
199 if (!efi_enabled(EFI_BOOT))
202 /* We register the efi directory at /sys/firmware/efi */
203 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
205 pr_err("efi: Firmware registration failed.\n");
209 error = generic_ops_register();
213 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
215 pr_err("efi: Sysfs attribute export failed with error %d.\n",
220 error = efi_runtime_map_init(efi_kobj);
222 goto err_remove_group;
224 /* and the standard mountpoint for efivarfs */
225 error = sysfs_create_mount_point(efi_kobj, "efivars");
227 pr_err("efivars: Subsystem registration failed.\n");
228 goto err_remove_group;
234 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
236 generic_ops_unregister();
238 kobject_put(efi_kobj);
242 subsys_initcall(efisubsys_init);
245 * Find the efi memory descriptor for a given physical address. Given a
246 * physicall address, determine if it exists within an EFI Memory Map entry,
247 * and if so, populate the supplied memory descriptor with the appropriate
250 int __init efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
252 struct efi_memory_map *map = efi.memmap;
255 if (!efi_enabled(EFI_MEMMAP)) {
256 pr_err_once("EFI_MEMMAP is not enabled.\n");
261 pr_err_once("efi.memmap is not set.\n");
265 pr_err_once("out_md is null.\n");
268 if (WARN_ON_ONCE(!map->phys_map))
270 if (WARN_ON_ONCE(map->nr_map == 0) || WARN_ON_ONCE(map->desc_size == 0))
273 e = map->phys_map + map->nr_map * map->desc_size;
274 for (p = map->phys_map; p < e; p += map->desc_size) {
275 efi_memory_desc_t *md;
280 * If a driver calls this after efi_free_boot_services,
281 * ->map will be NULL, and the target may also not be mapped.
282 * So just always get our own virtual map on the CPU.
285 md = early_memremap((phys_addr_t)p, sizeof (*md));
287 pr_err_once("early_memremap(%p, %zu) failed.\n",
292 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
293 md->type != EFI_BOOT_SERVICES_DATA &&
294 md->type != EFI_RUNTIME_SERVICES_DATA) {
295 early_memunmap(md, sizeof (*md));
299 size = md->num_pages << EFI_PAGE_SHIFT;
300 end = md->phys_addr + size;
301 if (phys_addr >= md->phys_addr && phys_addr < end) {
302 memcpy(out_md, md, sizeof(*out_md));
303 early_memunmap(md, sizeof (*md));
307 early_memunmap(md, sizeof (*md));
309 pr_err_once("requested map not found.\n");
314 * Calculate the highest address of an efi memory descriptor.
316 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
318 u64 size = md->num_pages << EFI_PAGE_SHIFT;
319 u64 end = md->phys_addr + size;
324 * We can't ioremap data in EFI boot services RAM, because we've already mapped
325 * it as RAM. So, look it up in the existing EFI memory map instead. Only
326 * callable after efi_enter_virtual_mode and before efi_free_boot_services.
328 void __iomem *efi_lookup_mapped_addr(u64 phys_addr)
330 struct efi_memory_map *map;
335 if (WARN_ON(!map->map))
337 for (p = map->map; p < map->map_end; p += map->desc_size) {
338 efi_memory_desc_t *md = p;
339 u64 size = md->num_pages << EFI_PAGE_SHIFT;
340 u64 end = md->phys_addr + size;
341 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
342 md->type != EFI_BOOT_SERVICES_CODE &&
343 md->type != EFI_BOOT_SERVICES_DATA)
347 if (phys_addr >= md->phys_addr && phys_addr < end) {
348 phys_addr += md->virt_addr - md->phys_addr;
349 return (__force void __iomem *)(unsigned long)phys_addr;
355 static __initdata efi_config_table_type_t common_tables[] = {
356 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
357 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
358 {HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
359 {MPS_TABLE_GUID, "MPS", &efi.mps},
360 {SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
361 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
362 {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
363 {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
364 {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
365 {NULL_GUID, NULL, NULL},
368 static __init int match_config_table(efi_guid_t *guid,
370 efi_config_table_type_t *table_types)
375 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
376 if (!efi_guidcmp(*guid, table_types[i].guid)) {
377 *(table_types[i].ptr) = table;
378 pr_cont(" %s=0x%lx ",
379 table_types[i].name, table);
388 int __init efi_config_parse_tables(void *config_tables, int count, int sz,
389 efi_config_table_type_t *arch_tables)
394 tablep = config_tables;
396 for (i = 0; i < count; i++) {
400 if (efi_enabled(EFI_64BIT)) {
402 guid = ((efi_config_table_64_t *)tablep)->guid;
403 table64 = ((efi_config_table_64_t *)tablep)->table;
408 pr_err("Table located above 4GB, disabling EFI.\n");
413 guid = ((efi_config_table_32_t *)tablep)->guid;
414 table = ((efi_config_table_32_t *)tablep)->table;
417 if (!match_config_table(&guid, table, common_tables))
418 match_config_table(&guid, table, arch_tables);
423 set_bit(EFI_CONFIG_TABLES, &efi.flags);
427 int __init efi_config_init(efi_config_table_type_t *arch_tables)
432 if (efi_enabled(EFI_64BIT))
433 sz = sizeof(efi_config_table_64_t);
435 sz = sizeof(efi_config_table_32_t);
438 * Let's see what config tables the firmware passed to us.
440 config_tables = early_memremap(efi.systab->tables,
441 efi.systab->nr_tables * sz);
442 if (config_tables == NULL) {
443 pr_err("Could not map Configuration table!\n");
447 ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
450 early_memunmap(config_tables, efi.systab->nr_tables * sz);
454 #ifdef CONFIG_EFI_VARS_MODULE
455 static int __init efi_load_efivars(void)
457 struct platform_device *pdev;
459 if (!efi_enabled(EFI_RUNTIME_SERVICES))
462 pdev = platform_device_register_simple("efivars", 0, NULL, 0);
463 return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
465 device_initcall(efi_load_efivars);
468 #ifdef CONFIG_EFI_PARAMS_FROM_FDT
470 #define UEFI_PARAM(name, prop, field) \
474 offsetof(struct efi_fdt_params, field), \
475 FIELD_SIZEOF(struct efi_fdt_params, field) \
478 static __initdata struct {
480 const char propname[32];
484 UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
485 UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
486 UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
487 UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
488 UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
497 static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
498 int depth, void *data)
500 struct param_info *info = data;
506 if (depth != 1 || strcmp(uname, "chosen") != 0)
509 for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
510 prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len);
513 dest = info->params + dt_params[i].offset;
516 val = of_read_number(prop, len / sizeof(u32));
518 if (dt_params[i].size == sizeof(u32))
524 pr_info(" %s: 0x%0*llx\n", dt_params[i].name,
525 dt_params[i].size * 2, val);
530 int __init efi_get_fdt_params(struct efi_fdt_params *params, int verbose)
532 struct param_info info;
535 pr_info("Getting EFI parameters from FDT:\n");
537 info.verbose = verbose;
539 info.params = params;
541 ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
543 pr_info("UEFI not found.\n");
545 pr_err("Can't find '%s' in device tree!\n",
546 dt_params[info.found].name);
550 #endif /* CONFIG_EFI_PARAMS_FROM_FDT */
552 static __initdata char memory_type_name[][20] = {
560 "Conventional Memory",
562 "ACPI Reclaim Memory",
569 char * __init efi_md_typeattr_format(char *buf, size_t size,
570 const efi_memory_desc_t *md)
577 if (md->type >= ARRAY_SIZE(memory_type_name))
578 type_len = snprintf(pos, size, "[type=%u", md->type);
580 type_len = snprintf(pos, size, "[%-*s",
581 (int)(sizeof(memory_type_name[0]) - 1),
582 memory_type_name[md->type]);
583 if (type_len >= size)
589 attr = md->attribute;
590 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
591 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_WP |
592 EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME))
593 snprintf(pos, size, "|attr=0x%016llx]",
594 (unsigned long long)attr);
596 snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
597 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
598 attr & EFI_MEMORY_XP ? "XP" : "",
599 attr & EFI_MEMORY_RP ? "RP" : "",
600 attr & EFI_MEMORY_WP ? "WP" : "",
601 attr & EFI_MEMORY_UCE ? "UCE" : "",
602 attr & EFI_MEMORY_WB ? "WB" : "",
603 attr & EFI_MEMORY_WT ? "WT" : "",
604 attr & EFI_MEMORY_WC ? "WC" : "",
605 attr & EFI_MEMORY_UC ? "UC" : "");