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 = __ATTR_RO_MODE(systab, 0400);
118 #define EFI_FIELD(var) efi.var
120 #define EFI_ATTR_SHOW(name) \
121 static ssize_t name##_show(struct kobject *kobj, \
122 struct kobj_attribute *attr, char *buf) \
124 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
127 EFI_ATTR_SHOW(fw_vendor);
128 EFI_ATTR_SHOW(runtime);
129 EFI_ATTR_SHOW(config_table);
131 static ssize_t fw_platform_size_show(struct kobject *kobj,
132 struct kobj_attribute *attr, char *buf)
134 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
137 static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
138 static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
139 static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
140 static struct kobj_attribute efi_attr_fw_platform_size =
141 __ATTR_RO(fw_platform_size);
143 static struct attribute *efi_subsys_attrs[] = {
144 &efi_attr_systab.attr,
145 &efi_attr_fw_vendor.attr,
146 &efi_attr_runtime.attr,
147 &efi_attr_config_table.attr,
148 &efi_attr_fw_platform_size.attr,
152 static umode_t efi_attr_is_visible(struct kobject *kobj,
153 struct attribute *attr, int n)
155 if (attr == &efi_attr_fw_vendor.attr) {
156 if (efi_enabled(EFI_PARAVIRT) ||
157 efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
159 } else if (attr == &efi_attr_runtime.attr) {
160 if (efi.runtime == EFI_INVALID_TABLE_ADDR)
162 } else if (attr == &efi_attr_config_table.attr) {
163 if (efi.config_table == EFI_INVALID_TABLE_ADDR)
170 static struct attribute_group efi_subsys_attr_group = {
171 .attrs = efi_subsys_attrs,
172 .is_visible = efi_attr_is_visible,
175 static struct efivars generic_efivars;
176 static struct efivar_operations generic_ops;
178 static int generic_ops_register(void)
180 generic_ops.get_variable = efi.get_variable;
181 generic_ops.set_variable = efi.set_variable;
182 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
183 generic_ops.get_next_variable = efi.get_next_variable;
184 generic_ops.query_variable_store = efi_query_variable_store;
186 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
189 static void generic_ops_unregister(void)
191 efivars_unregister(&generic_efivars);
195 * We register the efi subsystem with the firmware subsystem and the
196 * efivars subsystem with the efi subsystem, if the system was booted with
199 static int __init efisubsys_init(void)
203 if (!efi_enabled(EFI_BOOT))
206 /* We register the efi directory at /sys/firmware/efi */
207 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
209 pr_err("efi: Firmware registration failed.\n");
213 error = generic_ops_register();
217 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
219 pr_err("efi: Sysfs attribute export failed with error %d.\n",
224 error = efi_runtime_map_init(efi_kobj);
226 goto err_remove_group;
228 /* and the standard mountpoint for efivarfs */
229 error = sysfs_create_mount_point(efi_kobj, "efivars");
231 pr_err("efivars: Subsystem registration failed.\n");
232 goto err_remove_group;
238 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
240 generic_ops_unregister();
242 kobject_put(efi_kobj);
246 subsys_initcall(efisubsys_init);
249 * Find the efi memory descriptor for a given physical address. Given a
250 * physicall address, determine if it exists within an EFI Memory Map entry,
251 * and if so, populate the supplied memory descriptor with the appropriate
254 int __init efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
256 struct efi_memory_map *map = efi.memmap;
259 if (!efi_enabled(EFI_MEMMAP)) {
260 pr_err_once("EFI_MEMMAP is not enabled.\n");
265 pr_err_once("efi.memmap is not set.\n");
269 pr_err_once("out_md is null.\n");
272 if (WARN_ON_ONCE(!map->phys_map))
274 if (WARN_ON_ONCE(map->nr_map == 0) || WARN_ON_ONCE(map->desc_size == 0))
277 e = map->phys_map + map->nr_map * map->desc_size;
278 for (p = map->phys_map; p < e; p += map->desc_size) {
279 efi_memory_desc_t *md;
284 * If a driver calls this after efi_free_boot_services,
285 * ->map will be NULL, and the target may also not be mapped.
286 * So just always get our own virtual map on the CPU.
289 md = early_memremap(p, sizeof (*md));
291 pr_err_once("early_memremap(%pa, %zu) failed.\n",
296 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
297 md->type != EFI_BOOT_SERVICES_DATA &&
298 md->type != EFI_RUNTIME_SERVICES_DATA) {
299 early_memunmap(md, sizeof (*md));
303 size = md->num_pages << EFI_PAGE_SHIFT;
304 end = md->phys_addr + size;
305 if (phys_addr >= md->phys_addr && phys_addr < end) {
306 memcpy(out_md, md, sizeof(*out_md));
307 early_memunmap(md, sizeof (*md));
311 early_memunmap(md, sizeof (*md));
317 * Calculate the highest address of an efi memory descriptor.
319 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
321 u64 size = md->num_pages << EFI_PAGE_SHIFT;
322 u64 end = md->phys_addr + size;
326 static __initdata efi_config_table_type_t common_tables[] = {
327 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
328 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
329 {HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
330 {MPS_TABLE_GUID, "MPS", &efi.mps},
331 {SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
332 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
333 {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
334 {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
335 {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
336 {EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table},
337 {NULL_GUID, NULL, NULL},
340 static __init int match_config_table(efi_guid_t *guid,
342 efi_config_table_type_t *table_types)
347 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
348 if (!efi_guidcmp(*guid, table_types[i].guid)) {
349 *(table_types[i].ptr) = table;
350 pr_cont(" %s=0x%lx ",
351 table_types[i].name, table);
360 int __init efi_config_parse_tables(void *config_tables, int count, int sz,
361 efi_config_table_type_t *arch_tables)
366 tablep = config_tables;
368 for (i = 0; i < count; i++) {
372 if (efi_enabled(EFI_64BIT)) {
374 guid = ((efi_config_table_64_t *)tablep)->guid;
375 table64 = ((efi_config_table_64_t *)tablep)->table;
380 pr_err("Table located above 4GB, disabling EFI.\n");
385 guid = ((efi_config_table_32_t *)tablep)->guid;
386 table = ((efi_config_table_32_t *)tablep)->table;
389 if (!match_config_table(&guid, table, common_tables))
390 match_config_table(&guid, table, arch_tables);
395 set_bit(EFI_CONFIG_TABLES, &efi.flags);
397 /* Parse the EFI Properties table if it exists */
398 if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {
399 efi_properties_table_t *tbl;
401 tbl = early_memremap(efi.properties_table, sizeof(*tbl));
403 pr_err("Could not map Properties table!\n");
407 if (tbl->memory_protection_attribute &
408 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
409 set_bit(EFI_NX_PE_DATA, &efi.flags);
411 early_memunmap(tbl, sizeof(*tbl));
417 int __init efi_config_init(efi_config_table_type_t *arch_tables)
422 if (efi_enabled(EFI_64BIT))
423 sz = sizeof(efi_config_table_64_t);
425 sz = sizeof(efi_config_table_32_t);
428 * Let's see what config tables the firmware passed to us.
430 config_tables = early_memremap(efi.systab->tables,
431 efi.systab->nr_tables * sz);
432 if (config_tables == NULL) {
433 pr_err("Could not map Configuration table!\n");
437 ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
440 early_memunmap(config_tables, efi.systab->nr_tables * sz);
444 #ifdef CONFIG_EFI_VARS_MODULE
445 static int __init efi_load_efivars(void)
447 struct platform_device *pdev;
449 if (!efi_enabled(EFI_RUNTIME_SERVICES))
452 pdev = platform_device_register_simple("efivars", 0, NULL, 0);
453 return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
455 device_initcall(efi_load_efivars);
458 #ifdef CONFIG_EFI_PARAMS_FROM_FDT
460 #define UEFI_PARAM(name, prop, field) \
464 offsetof(struct efi_fdt_params, field), \
465 FIELD_SIZEOF(struct efi_fdt_params, field) \
468 static __initdata struct {
470 const char propname[32];
474 UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
475 UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
476 UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
477 UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
478 UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
486 static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
487 int depth, void *data)
489 struct param_info *info = data;
495 if (depth != 1 || strcmp(uname, "chosen") != 0)
498 for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
499 prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len);
502 dest = info->params + dt_params[i].offset;
505 val = of_read_number(prop, len / sizeof(u32));
507 if (dt_params[i].size == sizeof(u32))
512 if (efi_enabled(EFI_DBG))
513 pr_info(" %s: 0x%0*llx\n", dt_params[i].name,
514 dt_params[i].size * 2, val);
519 int __init efi_get_fdt_params(struct efi_fdt_params *params)
521 struct param_info info;
524 pr_info("Getting EFI parameters from FDT:\n");
527 info.params = params;
529 ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
531 pr_info("UEFI not found.\n");
533 pr_err("Can't find '%s' in device tree!\n",
534 dt_params[info.found].name);
538 #endif /* CONFIG_EFI_PARAMS_FROM_FDT */
540 static __initdata char memory_type_name[][20] = {
548 "Conventional Memory",
550 "ACPI Reclaim Memory",
557 char * __init efi_md_typeattr_format(char *buf, size_t size,
558 const efi_memory_desc_t *md)
565 if (md->type >= ARRAY_SIZE(memory_type_name))
566 type_len = snprintf(pos, size, "[type=%u", md->type);
568 type_len = snprintf(pos, size, "[%-*s",
569 (int)(sizeof(memory_type_name[0]) - 1),
570 memory_type_name[md->type]);
571 if (type_len >= size)
577 attr = md->attribute;
578 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
579 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
580 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
581 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
582 snprintf(pos, size, "|attr=0x%016llx]",
583 (unsigned long long)attr);
585 snprintf(pos, size, "|%3s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
586 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
587 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
588 attr & EFI_MEMORY_XP ? "XP" : "",
589 attr & EFI_MEMORY_RP ? "RP" : "",
590 attr & EFI_MEMORY_WP ? "WP" : "",
591 attr & EFI_MEMORY_RO ? "RO" : "",
592 attr & EFI_MEMORY_UCE ? "UCE" : "",
593 attr & EFI_MEMORY_WB ? "WB" : "",
594 attr & EFI_MEMORY_WT ? "WT" : "",
595 attr & EFI_MEMORY_WC ? "WC" : "",
596 attr & EFI_MEMORY_UC ? "UC" : "");
601 * efi_mem_attributes - lookup memmap attributes for physical address
602 * @phys_addr: the physical address to lookup
604 * Search in the EFI memory map for the region covering
605 * @phys_addr. Returns the EFI memory attributes if the region
606 * was found in the memory map, 0 otherwise.
608 * Despite being marked __weak, most architectures should *not*
609 * override this function. It is __weak solely for the benefit
610 * of ia64 which has a funky EFI memory map that doesn't work
611 * the same way as other architectures.
613 u64 __weak efi_mem_attributes(unsigned long phys_addr)
615 struct efi_memory_map *map;
616 efi_memory_desc_t *md;
619 if (!efi_enabled(EFI_MEMMAP))
623 for (p = map->map; p < map->map_end; p += map->desc_size) {
625 if ((md->phys_addr <= phys_addr) &&
626 (phys_addr < (md->phys_addr +
627 (md->num_pages << EFI_PAGE_SHIFT))))
628 return md->attribute;