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)
61 if (parse_option_str(str, "noruntime"))
62 disable_runtime = true;
66 early_param("efi", parse_efi_cmdline);
68 struct kobject *efi_kobj;
71 * Let's not leave out systab information that snuck into
74 static ssize_t systab_show(struct kobject *kobj,
75 struct kobj_attribute *attr, char *buf)
82 if (efi.mps != EFI_INVALID_TABLE_ADDR)
83 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
84 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
85 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
86 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
87 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
89 * If both SMBIOS and SMBIOS3 entry points are implemented, the
90 * SMBIOS3 entry point shall be preferred, so we list it first to
91 * let applications stop parsing after the first match.
93 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
94 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
95 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
96 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
97 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
98 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
99 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
100 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
101 if (efi.uga != EFI_INVALID_TABLE_ADDR)
102 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
107 static struct kobj_attribute efi_attr_systab =
108 __ATTR(systab, 0400, systab_show, NULL);
110 #define EFI_FIELD(var) efi.var
112 #define EFI_ATTR_SHOW(name) \
113 static ssize_t name##_show(struct kobject *kobj, \
114 struct kobj_attribute *attr, char *buf) \
116 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
119 EFI_ATTR_SHOW(fw_vendor);
120 EFI_ATTR_SHOW(runtime);
121 EFI_ATTR_SHOW(config_table);
123 static ssize_t fw_platform_size_show(struct kobject *kobj,
124 struct kobj_attribute *attr, char *buf)
126 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
129 static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
130 static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
131 static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
132 static struct kobj_attribute efi_attr_fw_platform_size =
133 __ATTR_RO(fw_platform_size);
135 static struct attribute *efi_subsys_attrs[] = {
136 &efi_attr_systab.attr,
137 &efi_attr_fw_vendor.attr,
138 &efi_attr_runtime.attr,
139 &efi_attr_config_table.attr,
140 &efi_attr_fw_platform_size.attr,
144 static umode_t efi_attr_is_visible(struct kobject *kobj,
145 struct attribute *attr, int n)
147 if (attr == &efi_attr_fw_vendor.attr) {
148 if (efi_enabled(EFI_PARAVIRT) ||
149 efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
151 } else if (attr == &efi_attr_runtime.attr) {
152 if (efi.runtime == EFI_INVALID_TABLE_ADDR)
154 } else if (attr == &efi_attr_config_table.attr) {
155 if (efi.config_table == EFI_INVALID_TABLE_ADDR)
162 static struct attribute_group efi_subsys_attr_group = {
163 .attrs = efi_subsys_attrs,
164 .is_visible = efi_attr_is_visible,
167 static struct efivars generic_efivars;
168 static struct efivar_operations generic_ops;
170 static int generic_ops_register(void)
172 generic_ops.get_variable = efi.get_variable;
173 generic_ops.set_variable = efi.set_variable;
174 generic_ops.get_next_variable = efi.get_next_variable;
175 generic_ops.query_variable_store = efi_query_variable_store;
177 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
180 static void generic_ops_unregister(void)
182 efivars_unregister(&generic_efivars);
186 * We register the efi subsystem with the firmware subsystem and the
187 * efivars subsystem with the efi subsystem, if the system was booted with
190 static int __init efisubsys_init(void)
194 if (!efi_enabled(EFI_BOOT))
197 /* We register the efi directory at /sys/firmware/efi */
198 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
200 pr_err("efi: Firmware registration failed.\n");
204 error = generic_ops_register();
208 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
210 pr_err("efi: Sysfs attribute export failed with error %d.\n",
215 error = efi_runtime_map_init(efi_kobj);
217 goto err_remove_group;
219 /* and the standard mountpoint for efivarfs */
220 error = sysfs_create_mount_point(efi_kobj, "efivars");
222 pr_err("efivars: Subsystem registration failed.\n");
223 goto err_remove_group;
229 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
231 generic_ops_unregister();
233 kobject_put(efi_kobj);
237 subsys_initcall(efisubsys_init);
240 * Find the efi memory descriptor for a given physical address. Given a
241 * physicall address, determine if it exists within an EFI Memory Map entry,
242 * and if so, populate the supplied memory descriptor with the appropriate
245 int __init efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
247 struct efi_memory_map *map = efi.memmap;
250 if (!efi_enabled(EFI_MEMMAP)) {
251 pr_err_once("EFI_MEMMAP is not enabled.\n");
256 pr_err_once("efi.memmap is not set.\n");
260 pr_err_once("out_md is null.\n");
263 if (WARN_ON_ONCE(!map->phys_map))
265 if (WARN_ON_ONCE(map->nr_map == 0) || WARN_ON_ONCE(map->desc_size == 0))
268 e = map->phys_map + map->nr_map * map->desc_size;
269 for (p = map->phys_map; p < e; p += map->desc_size) {
270 efi_memory_desc_t *md;
275 * If a driver calls this after efi_free_boot_services,
276 * ->map will be NULL, and the target may also not be mapped.
277 * So just always get our own virtual map on the CPU.
280 md = early_memremap((phys_addr_t)p, sizeof (*md));
282 pr_err_once("early_memremap(%p, %zu) failed.\n",
287 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
288 md->type != EFI_BOOT_SERVICES_DATA &&
289 md->type != EFI_RUNTIME_SERVICES_DATA) {
290 early_memunmap(md, sizeof (*md));
294 size = md->num_pages << EFI_PAGE_SHIFT;
295 end = md->phys_addr + size;
296 if (phys_addr >= md->phys_addr && phys_addr < end) {
297 memcpy(out_md, md, sizeof(*out_md));
298 early_memunmap(md, sizeof (*md));
302 early_memunmap(md, sizeof (*md));
304 pr_err_once("requested map not found.\n");
309 * Calculate the highest address of an efi memory descriptor.
311 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
313 u64 size = md->num_pages << EFI_PAGE_SHIFT;
314 u64 end = md->phys_addr + size;
319 * We can't ioremap data in EFI boot services RAM, because we've already mapped
320 * it as RAM. So, look it up in the existing EFI memory map instead. Only
321 * callable after efi_enter_virtual_mode and before efi_free_boot_services.
323 void __iomem *efi_lookup_mapped_addr(u64 phys_addr)
325 struct efi_memory_map *map;
330 if (WARN_ON(!map->map))
332 for (p = map->map; p < map->map_end; p += map->desc_size) {
333 efi_memory_desc_t *md = p;
334 u64 size = md->num_pages << EFI_PAGE_SHIFT;
335 u64 end = md->phys_addr + size;
336 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
337 md->type != EFI_BOOT_SERVICES_CODE &&
338 md->type != EFI_BOOT_SERVICES_DATA)
342 if (phys_addr >= md->phys_addr && phys_addr < end) {
343 phys_addr += md->virt_addr - md->phys_addr;
344 return (__force void __iomem *)(unsigned long)phys_addr;
350 static __initdata efi_config_table_type_t common_tables[] = {
351 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
352 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
353 {HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
354 {MPS_TABLE_GUID, "MPS", &efi.mps},
355 {SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
356 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
357 {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
358 {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
359 {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
360 {NULL_GUID, NULL, NULL},
363 static __init int match_config_table(efi_guid_t *guid,
365 efi_config_table_type_t *table_types)
370 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
371 if (!efi_guidcmp(*guid, table_types[i].guid)) {
372 *(table_types[i].ptr) = table;
373 pr_cont(" %s=0x%lx ",
374 table_types[i].name, table);
383 int __init efi_config_parse_tables(void *config_tables, int count, int sz,
384 efi_config_table_type_t *arch_tables)
389 tablep = config_tables;
391 for (i = 0; i < count; i++) {
395 if (efi_enabled(EFI_64BIT)) {
397 guid = ((efi_config_table_64_t *)tablep)->guid;
398 table64 = ((efi_config_table_64_t *)tablep)->table;
403 pr_err("Table located above 4GB, disabling EFI.\n");
408 guid = ((efi_config_table_32_t *)tablep)->guid;
409 table = ((efi_config_table_32_t *)tablep)->table;
412 if (!match_config_table(&guid, table, common_tables))
413 match_config_table(&guid, table, arch_tables);
418 set_bit(EFI_CONFIG_TABLES, &efi.flags);
422 int __init efi_config_init(efi_config_table_type_t *arch_tables)
427 if (efi_enabled(EFI_64BIT))
428 sz = sizeof(efi_config_table_64_t);
430 sz = sizeof(efi_config_table_32_t);
433 * Let's see what config tables the firmware passed to us.
435 config_tables = early_memremap(efi.systab->tables,
436 efi.systab->nr_tables * sz);
437 if (config_tables == NULL) {
438 pr_err("Could not map Configuration table!\n");
442 ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
445 early_memunmap(config_tables, efi.systab->nr_tables * sz);
449 #ifdef CONFIG_EFI_VARS_MODULE
450 static int __init efi_load_efivars(void)
452 struct platform_device *pdev;
454 if (!efi_enabled(EFI_RUNTIME_SERVICES))
457 pdev = platform_device_register_simple("efivars", 0, NULL, 0);
458 return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
460 device_initcall(efi_load_efivars);
463 #ifdef CONFIG_EFI_PARAMS_FROM_FDT
465 #define UEFI_PARAM(name, prop, field) \
469 offsetof(struct efi_fdt_params, field), \
470 FIELD_SIZEOF(struct efi_fdt_params, field) \
473 static __initdata struct {
475 const char propname[32];
479 UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
480 UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
481 UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
482 UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
483 UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
492 static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
493 int depth, void *data)
495 struct param_info *info = data;
501 if (depth != 1 || strcmp(uname, "chosen") != 0)
504 for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
505 prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len);
508 dest = info->params + dt_params[i].offset;
511 val = of_read_number(prop, len / sizeof(u32));
513 if (dt_params[i].size == sizeof(u32))
519 pr_info(" %s: 0x%0*llx\n", dt_params[i].name,
520 dt_params[i].size * 2, val);
525 int __init efi_get_fdt_params(struct efi_fdt_params *params, int verbose)
527 struct param_info info;
530 pr_info("Getting EFI parameters from FDT:\n");
532 info.verbose = verbose;
534 info.params = params;
536 ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
538 pr_info("UEFI not found.\n");
540 pr_err("Can't find '%s' in device tree!\n",
541 dt_params[info.found].name);
545 #endif /* CONFIG_EFI_PARAMS_FROM_FDT */
547 static __initdata char memory_type_name[][20] = {
555 "Conventional Memory",
557 "ACPI Reclaim Memory",
564 char * __init efi_md_typeattr_format(char *buf, size_t size,
565 const efi_memory_desc_t *md)
572 if (md->type >= ARRAY_SIZE(memory_type_name))
573 type_len = snprintf(pos, size, "[type=%u", md->type);
575 type_len = snprintf(pos, size, "[%-*s",
576 (int)(sizeof(memory_type_name[0]) - 1),
577 memory_type_name[md->type]);
578 if (type_len >= size)
584 attr = md->attribute;
585 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
586 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_WP |
587 EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME))
588 snprintf(pos, size, "|attr=0x%016llx]",
589 (unsigned long long)attr);
591 snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
592 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
593 attr & EFI_MEMORY_XP ? "XP" : "",
594 attr & EFI_MEMORY_RP ? "RP" : "",
595 attr & EFI_MEMORY_WP ? "WP" : "",
596 attr & EFI_MEMORY_UCE ? "UCE" : "",
597 attr & EFI_MEMORY_WB ? "WB" : "",
598 attr & EFI_MEMORY_WT ? "WT" : "",
599 attr & EFI_MEMORY_WC ? "WC" : "",
600 attr & EFI_MEMORY_UC ? "UC" : "");