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 #include <asm/early_ioremap.h>
30 struct efi __read_mostly efi = {
31 .mps = EFI_INVALID_TABLE_ADDR,
32 .acpi = EFI_INVALID_TABLE_ADDR,
33 .acpi20 = EFI_INVALID_TABLE_ADDR,
34 .smbios = EFI_INVALID_TABLE_ADDR,
35 .smbios3 = EFI_INVALID_TABLE_ADDR,
36 .sal_systab = EFI_INVALID_TABLE_ADDR,
37 .boot_info = EFI_INVALID_TABLE_ADDR,
38 .hcdp = EFI_INVALID_TABLE_ADDR,
39 .uga = EFI_INVALID_TABLE_ADDR,
40 .uv_systab = EFI_INVALID_TABLE_ADDR,
41 .fw_vendor = EFI_INVALID_TABLE_ADDR,
42 .runtime = EFI_INVALID_TABLE_ADDR,
43 .config_table = EFI_INVALID_TABLE_ADDR,
44 .esrt = EFI_INVALID_TABLE_ADDR,
45 .properties_table = EFI_INVALID_TABLE_ADDR,
46 .mem_attr_table = EFI_INVALID_TABLE_ADDR,
50 static bool disable_runtime;
51 static int __init setup_noefi(char *arg)
53 disable_runtime = true;
56 early_param("noefi", setup_noefi);
58 bool efi_runtime_disabled(void)
60 return disable_runtime;
63 static int __init parse_efi_cmdline(char *str)
66 pr_warn("need at least one option\n");
70 if (parse_option_str(str, "debug"))
71 set_bit(EFI_DBG, &efi.flags);
73 if (parse_option_str(str, "noruntime"))
74 disable_runtime = true;
78 early_param("efi", parse_efi_cmdline);
80 struct kobject *efi_kobj;
83 * Let's not leave out systab information that snuck into
86 static ssize_t systab_show(struct kobject *kobj,
87 struct kobj_attribute *attr, char *buf)
94 if (efi.mps != EFI_INVALID_TABLE_ADDR)
95 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
96 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
97 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
98 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
99 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
101 * If both SMBIOS and SMBIOS3 entry points are implemented, the
102 * SMBIOS3 entry point shall be preferred, so we list it first to
103 * let applications stop parsing after the first match.
105 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
106 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
107 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
108 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
109 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
110 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
111 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
112 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
113 if (efi.uga != EFI_INVALID_TABLE_ADDR)
114 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
119 static struct kobj_attribute efi_attr_systab =
120 __ATTR(systab, 0400, systab_show, NULL);
122 #define EFI_FIELD(var) efi.var
124 #define EFI_ATTR_SHOW(name) \
125 static ssize_t name##_show(struct kobject *kobj, \
126 struct kobj_attribute *attr, char *buf) \
128 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
131 EFI_ATTR_SHOW(fw_vendor);
132 EFI_ATTR_SHOW(runtime);
133 EFI_ATTR_SHOW(config_table);
135 static ssize_t fw_platform_size_show(struct kobject *kobj,
136 struct kobj_attribute *attr, char *buf)
138 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
141 static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
142 static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
143 static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
144 static struct kobj_attribute efi_attr_fw_platform_size =
145 __ATTR_RO(fw_platform_size);
147 static struct attribute *efi_subsys_attrs[] = {
148 &efi_attr_systab.attr,
149 &efi_attr_fw_vendor.attr,
150 &efi_attr_runtime.attr,
151 &efi_attr_config_table.attr,
152 &efi_attr_fw_platform_size.attr,
156 static umode_t efi_attr_is_visible(struct kobject *kobj,
157 struct attribute *attr, int n)
159 if (attr == &efi_attr_fw_vendor.attr) {
160 if (efi_enabled(EFI_PARAVIRT) ||
161 efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
163 } else if (attr == &efi_attr_runtime.attr) {
164 if (efi.runtime == EFI_INVALID_TABLE_ADDR)
166 } else if (attr == &efi_attr_config_table.attr) {
167 if (efi.config_table == EFI_INVALID_TABLE_ADDR)
174 static struct attribute_group efi_subsys_attr_group = {
175 .attrs = efi_subsys_attrs,
176 .is_visible = efi_attr_is_visible,
179 static struct efivars generic_efivars;
180 static struct efivar_operations generic_ops;
182 static int generic_ops_register(void)
184 generic_ops.get_variable = efi.get_variable;
185 generic_ops.set_variable = efi.set_variable;
186 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
187 generic_ops.get_next_variable = efi.get_next_variable;
188 generic_ops.query_variable_store = efi_query_variable_store;
190 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
193 static void generic_ops_unregister(void)
195 efivars_unregister(&generic_efivars);
199 * We register the efi subsystem with the firmware subsystem and the
200 * efivars subsystem with the efi subsystem, if the system was booted with
203 static int __init efisubsys_init(void)
207 if (!efi_enabled(EFI_BOOT))
210 /* We register the efi directory at /sys/firmware/efi */
211 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
213 pr_err("efi: Firmware registration failed.\n");
217 error = generic_ops_register();
221 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
223 pr_err("efi: Sysfs attribute export failed with error %d.\n",
228 error = efi_runtime_map_init(efi_kobj);
230 goto err_remove_group;
232 /* and the standard mountpoint for efivarfs */
233 error = sysfs_create_mount_point(efi_kobj, "efivars");
235 pr_err("efivars: Subsystem registration failed.\n");
236 goto err_remove_group;
242 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
244 generic_ops_unregister();
246 kobject_put(efi_kobj);
250 subsys_initcall(efisubsys_init);
253 * Find the efi memory descriptor for a given physical address. Given a
254 * physicall address, determine if it exists within an EFI Memory Map entry,
255 * and if so, populate the supplied memory descriptor with the appropriate
258 int __init efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
260 struct efi_memory_map *map = &efi.memmap;
263 if (!efi_enabled(EFI_MEMMAP)) {
264 pr_err_once("EFI_MEMMAP is not enabled.\n");
269 pr_err_once("efi.memmap is not set.\n");
273 pr_err_once("out_md is null.\n");
276 if (WARN_ON_ONCE(!map->phys_map))
278 if (WARN_ON_ONCE(map->nr_map == 0) || WARN_ON_ONCE(map->desc_size == 0))
281 e = map->phys_map + map->nr_map * map->desc_size;
282 for (p = map->phys_map; p < e; p += map->desc_size) {
283 efi_memory_desc_t *md;
288 * If a driver calls this after efi_free_boot_services,
289 * ->map will be NULL, and the target may also not be mapped.
290 * So just always get our own virtual map on the CPU.
293 md = early_memremap(p, sizeof (*md));
295 pr_err_once("early_memremap(%pa, %zu) failed.\n",
300 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
301 md->type != EFI_BOOT_SERVICES_DATA &&
302 md->type != EFI_RUNTIME_SERVICES_DATA) {
303 early_memunmap(md, sizeof (*md));
307 size = md->num_pages << EFI_PAGE_SHIFT;
308 end = md->phys_addr + size;
309 if (phys_addr >= md->phys_addr && phys_addr < end) {
310 memcpy(out_md, md, sizeof(*out_md));
311 early_memunmap(md, sizeof (*md));
315 early_memunmap(md, sizeof (*md));
317 pr_err_once("requested map not found.\n");
322 * Calculate the highest address of an efi memory descriptor.
324 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
326 u64 size = md->num_pages << EFI_PAGE_SHIFT;
327 u64 end = md->phys_addr + size;
331 static __initdata efi_config_table_type_t common_tables[] = {
332 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
333 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
334 {HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
335 {MPS_TABLE_GUID, "MPS", &efi.mps},
336 {SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
337 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
338 {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
339 {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
340 {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
341 {EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table},
342 {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table},
343 {NULL_GUID, NULL, NULL},
346 static __init int match_config_table(efi_guid_t *guid,
348 efi_config_table_type_t *table_types)
353 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
354 if (!efi_guidcmp(*guid, table_types[i].guid)) {
355 *(table_types[i].ptr) = table;
356 if (table_types[i].name)
357 pr_cont(" %s=0x%lx ",
358 table_types[i].name, table);
367 int __init efi_config_parse_tables(void *config_tables, int count, int sz,
368 efi_config_table_type_t *arch_tables)
373 tablep = config_tables;
375 for (i = 0; i < count; i++) {
379 if (efi_enabled(EFI_64BIT)) {
381 guid = ((efi_config_table_64_t *)tablep)->guid;
382 table64 = ((efi_config_table_64_t *)tablep)->table;
387 pr_err("Table located above 4GB, disabling EFI.\n");
392 guid = ((efi_config_table_32_t *)tablep)->guid;
393 table = ((efi_config_table_32_t *)tablep)->table;
396 if (!match_config_table(&guid, table, common_tables))
397 match_config_table(&guid, table, arch_tables);
402 set_bit(EFI_CONFIG_TABLES, &efi.flags);
404 /* Parse the EFI Properties table if it exists */
405 if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {
406 efi_properties_table_t *tbl;
408 tbl = early_memremap(efi.properties_table, sizeof(*tbl));
410 pr_err("Could not map Properties table!\n");
414 if (tbl->memory_protection_attribute &
415 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
416 set_bit(EFI_NX_PE_DATA, &efi.flags);
418 early_memunmap(tbl, sizeof(*tbl));
424 int __init efi_config_init(efi_config_table_type_t *arch_tables)
429 if (efi_enabled(EFI_64BIT))
430 sz = sizeof(efi_config_table_64_t);
432 sz = sizeof(efi_config_table_32_t);
435 * Let's see what config tables the firmware passed to us.
437 config_tables = early_memremap(efi.systab->tables,
438 efi.systab->nr_tables * sz);
439 if (config_tables == NULL) {
440 pr_err("Could not map Configuration table!\n");
444 ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
447 early_memunmap(config_tables, efi.systab->nr_tables * sz);
451 #ifdef CONFIG_EFI_VARS_MODULE
452 static int __init efi_load_efivars(void)
454 struct platform_device *pdev;
456 if (!efi_enabled(EFI_RUNTIME_SERVICES))
459 pdev = platform_device_register_simple("efivars", 0, NULL, 0);
460 return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
462 device_initcall(efi_load_efivars);
465 #ifdef CONFIG_EFI_PARAMS_FROM_FDT
467 #define UEFI_PARAM(name, prop, field) \
471 offsetof(struct efi_fdt_params, field), \
472 FIELD_SIZEOF(struct efi_fdt_params, field) \
475 static __initdata struct {
477 const char propname[32];
481 UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
482 UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
483 UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
484 UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
485 UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
493 static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
494 int depth, void *data)
496 struct param_info *info = data;
502 if (depth != 1 || strcmp(uname, "chosen") != 0)
505 for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
506 prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len);
509 dest = info->params + dt_params[i].offset;
512 val = of_read_number(prop, len / sizeof(u32));
514 if (dt_params[i].size == sizeof(u32))
519 if (efi_enabled(EFI_DBG))
520 pr_info(" %s: 0x%0*llx\n", dt_params[i].name,
521 dt_params[i].size * 2, val);
526 int __init efi_get_fdt_params(struct efi_fdt_params *params)
528 struct param_info info;
531 pr_info("Getting EFI parameters from FDT:\n");
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",
565 char * __init efi_md_typeattr_format(char *buf, size_t size,
566 const efi_memory_desc_t *md)
573 if (md->type >= ARRAY_SIZE(memory_type_name))
574 type_len = snprintf(pos, size, "[type=%u", md->type);
576 type_len = snprintf(pos, size, "[%-*s",
577 (int)(sizeof(memory_type_name[0]) - 1),
578 memory_type_name[md->type]);
579 if (type_len >= size)
585 attr = md->attribute;
586 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
587 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
588 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
590 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
591 snprintf(pos, size, "|attr=0x%016llx]",
592 (unsigned long long)attr);
595 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
596 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
597 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
598 attr & EFI_MEMORY_NV ? "NV" : "",
599 attr & EFI_MEMORY_XP ? "XP" : "",
600 attr & EFI_MEMORY_RP ? "RP" : "",
601 attr & EFI_MEMORY_WP ? "WP" : "",
602 attr & EFI_MEMORY_RO ? "RO" : "",
603 attr & EFI_MEMORY_UCE ? "UCE" : "",
604 attr & EFI_MEMORY_WB ? "WB" : "",
605 attr & EFI_MEMORY_WT ? "WT" : "",
606 attr & EFI_MEMORY_WC ? "WC" : "",
607 attr & EFI_MEMORY_UC ? "UC" : "");
612 * efi_mem_attributes - lookup memmap attributes for physical address
613 * @phys_addr: the physical address to lookup
615 * Search in the EFI memory map for the region covering
616 * @phys_addr. Returns the EFI memory attributes if the region
617 * was found in the memory map, 0 otherwise.
619 * Despite being marked __weak, most architectures should *not*
620 * override this function. It is __weak solely for the benefit
621 * of ia64 which has a funky EFI memory map that doesn't work
622 * the same way as other architectures.
624 u64 __weak efi_mem_attributes(unsigned long phys_addr)
626 efi_memory_desc_t *md;
628 if (!efi_enabled(EFI_MEMMAP))
631 for_each_efi_memory_desc(md) {
632 if ((md->phys_addr <= phys_addr) &&
633 (phys_addr < (md->phys_addr +
634 (md->num_pages << EFI_PAGE_SHIFT))))
635 return md->attribute;
640 int efi_status_to_err(efi_status_t status)
648 case EFI_INVALID_PARAMETER:
651 case EFI_OUT_OF_RESOURCES:
654 case EFI_DEVICE_ERROR:
657 case EFI_WRITE_PROTECTED:
660 case EFI_SECURITY_VIOLATION: