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,
43 .properties_table = EFI_INVALID_TABLE_ADDR,
47 static bool disable_runtime;
48 static int __init setup_noefi(char *arg)
50 disable_runtime = true;
53 early_param("noefi", setup_noefi);
55 bool efi_runtime_disabled(void)
57 return disable_runtime;
60 static int __init parse_efi_cmdline(char *str)
63 pr_warn("need at least one option\n");
67 if (parse_option_str(str, "debug"))
68 set_bit(EFI_DBG, &efi.flags);
70 if (parse_option_str(str, "noruntime"))
71 disable_runtime = true;
75 early_param("efi", parse_efi_cmdline);
77 struct kobject *efi_kobj;
80 * Let's not leave out systab information that snuck into
83 static ssize_t systab_show(struct kobject *kobj,
84 struct kobj_attribute *attr, char *buf)
91 if (efi.mps != EFI_INVALID_TABLE_ADDR)
92 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
93 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
94 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
95 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
96 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
98 * If both SMBIOS and SMBIOS3 entry points are implemented, the
99 * SMBIOS3 entry point shall be preferred, so we list it first to
100 * let applications stop parsing after the first match.
102 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
103 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
104 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
105 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
106 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
107 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
108 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
109 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
110 if (efi.uga != EFI_INVALID_TABLE_ADDR)
111 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
116 static struct kobj_attribute efi_attr_systab =
117 __ATTR(systab, 0400, systab_show, NULL);
119 #define EFI_FIELD(var) efi.var
121 #define EFI_ATTR_SHOW(name) \
122 static ssize_t name##_show(struct kobject *kobj, \
123 struct kobj_attribute *attr, char *buf) \
125 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
128 EFI_ATTR_SHOW(fw_vendor);
129 EFI_ATTR_SHOW(runtime);
130 EFI_ATTR_SHOW(config_table);
132 static ssize_t fw_platform_size_show(struct kobject *kobj,
133 struct kobj_attribute *attr, char *buf)
135 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
138 static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
139 static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
140 static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
141 static struct kobj_attribute efi_attr_fw_platform_size =
142 __ATTR_RO(fw_platform_size);
144 static struct attribute *efi_subsys_attrs[] = {
145 &efi_attr_systab.attr,
146 &efi_attr_fw_vendor.attr,
147 &efi_attr_runtime.attr,
148 &efi_attr_config_table.attr,
149 &efi_attr_fw_platform_size.attr,
153 static umode_t efi_attr_is_visible(struct kobject *kobj,
154 struct attribute *attr, int n)
156 if (attr == &efi_attr_fw_vendor.attr) {
157 if (efi_enabled(EFI_PARAVIRT) ||
158 efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
160 } else if (attr == &efi_attr_runtime.attr) {
161 if (efi.runtime == EFI_INVALID_TABLE_ADDR)
163 } else if (attr == &efi_attr_config_table.attr) {
164 if (efi.config_table == EFI_INVALID_TABLE_ADDR)
171 static 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);
196 * We register the efi subsystem with the firmware subsystem and the
197 * efivars subsystem with the efi subsystem, if the system was booted with
200 static int __init efisubsys_init(void)
204 if (!efi_enabled(EFI_BOOT))
207 /* We register the efi directory at /sys/firmware/efi */
208 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
210 pr_err("efi: Firmware registration failed.\n");
214 error = generic_ops_register();
218 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
220 pr_err("efi: Sysfs attribute export failed with error %d.\n",
225 error = efi_runtime_map_init(efi_kobj);
227 goto err_remove_group;
229 /* and the standard mountpoint for efivarfs */
230 error = sysfs_create_mount_point(efi_kobj, "efivars");
232 pr_err("efivars: Subsystem registration failed.\n");
233 goto err_remove_group;
239 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
241 generic_ops_unregister();
243 kobject_put(efi_kobj);
247 subsys_initcall(efisubsys_init);
250 * Find the efi memory descriptor for a given physical address. Given a
251 * physicall address, determine if it exists within an EFI Memory Map entry,
252 * and if so, populate the supplied memory descriptor with the appropriate
255 int __init efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
257 struct efi_memory_map *map = efi.memmap;
260 if (!efi_enabled(EFI_MEMMAP)) {
261 pr_err_once("EFI_MEMMAP is not enabled.\n");
266 pr_err_once("efi.memmap is not set.\n");
270 pr_err_once("out_md is null.\n");
273 if (WARN_ON_ONCE(!map->phys_map))
275 if (WARN_ON_ONCE(map->nr_map == 0) || WARN_ON_ONCE(map->desc_size == 0))
278 e = map->phys_map + map->nr_map * map->desc_size;
279 for (p = map->phys_map; p < e; p += map->desc_size) {
280 efi_memory_desc_t *md;
285 * If a driver calls this after efi_free_boot_services,
286 * ->map will be NULL, and the target may also not be mapped.
287 * So just always get our own virtual map on the CPU.
290 md = early_memremap(p, sizeof (*md));
292 pr_err_once("early_memremap(%pa, %zu) failed.\n",
297 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
298 md->type != EFI_BOOT_SERVICES_DATA &&
299 md->type != EFI_RUNTIME_SERVICES_DATA) {
300 early_memunmap(md, sizeof (*md));
304 size = md->num_pages << EFI_PAGE_SHIFT;
305 end = md->phys_addr + size;
306 if (phys_addr >= md->phys_addr && phys_addr < end) {
307 memcpy(out_md, md, sizeof(*out_md));
308 early_memunmap(md, sizeof (*md));
312 early_memunmap(md, sizeof (*md));
314 pr_err_once("requested map not found.\n");
319 * Calculate the highest address of an efi memory descriptor.
321 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
323 u64 size = md->num_pages << EFI_PAGE_SHIFT;
324 u64 end = md->phys_addr + size;
329 * We can't ioremap data in EFI boot services RAM, because we've already mapped
330 * it as RAM. So, look it up in the existing EFI memory map instead. Only
331 * callable after efi_enter_virtual_mode and before efi_free_boot_services.
333 void __iomem *efi_lookup_mapped_addr(u64 phys_addr)
335 struct efi_memory_map *map;
340 if (WARN_ON(!map->map))
342 for (p = map->map; p < map->map_end; p += map->desc_size) {
343 efi_memory_desc_t *md = p;
344 u64 size = md->num_pages << EFI_PAGE_SHIFT;
345 u64 end = md->phys_addr + size;
346 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
347 md->type != EFI_BOOT_SERVICES_CODE &&
348 md->type != EFI_BOOT_SERVICES_DATA)
352 if (phys_addr >= md->phys_addr && phys_addr < end) {
353 phys_addr += md->virt_addr - md->phys_addr;
354 return (__force void __iomem *)(unsigned long)phys_addr;
360 static __initdata efi_config_table_type_t common_tables[] = {
361 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
362 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
363 {HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
364 {MPS_TABLE_GUID, "MPS", &efi.mps},
365 {SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
366 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
367 {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
368 {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
369 {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
370 {EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table},
371 {NULL_GUID, NULL, NULL},
374 static __init int match_config_table(efi_guid_t *guid,
376 efi_config_table_type_t *table_types)
381 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
382 if (!efi_guidcmp(*guid, table_types[i].guid)) {
383 *(table_types[i].ptr) = table;
384 pr_cont(" %s=0x%lx ",
385 table_types[i].name, table);
394 int __init efi_config_parse_tables(void *config_tables, int count, int sz,
395 efi_config_table_type_t *arch_tables)
400 tablep = config_tables;
402 for (i = 0; i < count; i++) {
406 if (efi_enabled(EFI_64BIT)) {
408 guid = ((efi_config_table_64_t *)tablep)->guid;
409 table64 = ((efi_config_table_64_t *)tablep)->table;
414 pr_err("Table located above 4GB, disabling EFI.\n");
419 guid = ((efi_config_table_32_t *)tablep)->guid;
420 table = ((efi_config_table_32_t *)tablep)->table;
423 if (!match_config_table(&guid, table, common_tables))
424 match_config_table(&guid, table, arch_tables);
429 set_bit(EFI_CONFIG_TABLES, &efi.flags);
431 /* Parse the EFI Properties table if it exists */
432 if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {
433 efi_properties_table_t *tbl;
435 tbl = early_memremap(efi.properties_table, sizeof(*tbl));
437 pr_err("Could not map Properties table!\n");
441 if (tbl->memory_protection_attribute &
442 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
443 set_bit(EFI_NX_PE_DATA, &efi.flags);
445 early_memunmap(tbl, sizeof(*tbl));
451 int __init efi_config_init(efi_config_table_type_t *arch_tables)
456 if (efi_enabled(EFI_64BIT))
457 sz = sizeof(efi_config_table_64_t);
459 sz = sizeof(efi_config_table_32_t);
462 * Let's see what config tables the firmware passed to us.
464 config_tables = early_memremap(efi.systab->tables,
465 efi.systab->nr_tables * sz);
466 if (config_tables == NULL) {
467 pr_err("Could not map Configuration table!\n");
471 ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
474 early_memunmap(config_tables, efi.systab->nr_tables * sz);
478 #ifdef CONFIG_EFI_VARS_MODULE
479 static int __init efi_load_efivars(void)
481 struct platform_device *pdev;
483 if (!efi_enabled(EFI_RUNTIME_SERVICES))
486 pdev = platform_device_register_simple("efivars", 0, NULL, 0);
487 return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
489 device_initcall(efi_load_efivars);
492 #ifdef CONFIG_EFI_PARAMS_FROM_FDT
494 #define UEFI_PARAM(name, prop, field) \
498 offsetof(struct efi_fdt_params, field), \
499 FIELD_SIZEOF(struct efi_fdt_params, field) \
502 static __initdata struct {
504 const char propname[32];
508 UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
509 UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
510 UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
511 UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
512 UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
520 static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
521 int depth, void *data)
523 struct param_info *info = data;
529 if (depth != 1 || strcmp(uname, "chosen") != 0)
532 for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
533 prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len);
536 dest = info->params + dt_params[i].offset;
539 val = of_read_number(prop, len / sizeof(u32));
541 if (dt_params[i].size == sizeof(u32))
546 if (efi_enabled(EFI_DBG))
547 pr_info(" %s: 0x%0*llx\n", dt_params[i].name,
548 dt_params[i].size * 2, val);
553 int __init efi_get_fdt_params(struct efi_fdt_params *params)
555 struct param_info info;
558 pr_info("Getting EFI parameters from FDT:\n");
561 info.params = params;
563 ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
565 pr_info("UEFI not found.\n");
567 pr_err("Can't find '%s' in device tree!\n",
568 dt_params[info.found].name);
572 #endif /* CONFIG_EFI_PARAMS_FROM_FDT */
574 static __initdata char memory_type_name[][20] = {
582 "Conventional Memory",
584 "ACPI Reclaim Memory",
591 char * __init efi_md_typeattr_format(char *buf, size_t size,
592 const efi_memory_desc_t *md)
599 if (md->type >= ARRAY_SIZE(memory_type_name))
600 type_len = snprintf(pos, size, "[type=%u", md->type);
602 type_len = snprintf(pos, size, "[%-*s",
603 (int)(sizeof(memory_type_name[0]) - 1),
604 memory_type_name[md->type]);
605 if (type_len >= size)
611 attr = md->attribute;
612 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
613 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
614 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
615 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
616 snprintf(pos, size, "|attr=0x%016llx]",
617 (unsigned long long)attr);
619 snprintf(pos, size, "|%3s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
620 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
621 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
622 attr & EFI_MEMORY_XP ? "XP" : "",
623 attr & EFI_MEMORY_RP ? "RP" : "",
624 attr & EFI_MEMORY_WP ? "WP" : "",
625 attr & EFI_MEMORY_RO ? "RO" : "",
626 attr & EFI_MEMORY_UCE ? "UCE" : "",
627 attr & EFI_MEMORY_WB ? "WB" : "",
628 attr & EFI_MEMORY_WT ? "WT" : "",
629 attr & EFI_MEMORY_WC ? "WC" : "",
630 attr & EFI_MEMORY_UC ? "UC" : "");
635 * efi_mem_attributes - lookup memmap attributes for physical address
636 * @phys_addr: the physical address to lookup
638 * Search in the EFI memory map for the region covering
639 * @phys_addr. Returns the EFI memory attributes if the region
640 * was found in the memory map, 0 otherwise.
642 * Despite being marked __weak, most architectures should *not*
643 * override this function. It is __weak solely for the benefit
644 * of ia64 which has a funky EFI memory map that doesn't work
645 * the same way as other architectures.
647 u64 __weak efi_mem_attributes(unsigned long phys_addr)
649 struct efi_memory_map *map;
650 efi_memory_desc_t *md;
653 if (!efi_enabled(EFI_MEMMAP))
657 for (p = map->map; p < map->map_end; p += map->desc_size) {
659 if ((md->phys_addr <= phys_addr) &&
660 (phys_addr < (md->phys_addr +
661 (md->num_pages << EFI_PAGE_SHIFT))))
662 return md->attribute;