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 .sal_systab = EFI_INVALID_TABLE_ADDR,
34 .boot_info = EFI_INVALID_TABLE_ADDR,
35 .hcdp = EFI_INVALID_TABLE_ADDR,
36 .uga = EFI_INVALID_TABLE_ADDR,
37 .uv_systab = EFI_INVALID_TABLE_ADDR,
38 .fw_vendor = EFI_INVALID_TABLE_ADDR,
39 .runtime = EFI_INVALID_TABLE_ADDR,
40 .config_table = EFI_INVALID_TABLE_ADDR,
44 static bool disable_runtime;
45 static int __init setup_noefi(char *arg)
47 disable_runtime = true;
50 early_param("noefi", setup_noefi);
52 bool efi_runtime_disabled(void)
54 return disable_runtime;
57 static int __init parse_efi_cmdline(char *str)
59 if (parse_option_str(str, "noruntime"))
60 disable_runtime = true;
64 early_param("efi", parse_efi_cmdline);
66 static struct kobject *efi_kobj;
67 static struct kobject *efivars_kobj;
70 * Let's not leave out systab information that snuck into
73 static ssize_t systab_show(struct kobject *kobj,
74 struct kobj_attribute *attr, char *buf)
81 if (efi.mps != EFI_INVALID_TABLE_ADDR)
82 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
83 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
84 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
85 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
86 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
87 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
88 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
89 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
90 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
91 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
92 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
93 if (efi.uga != EFI_INVALID_TABLE_ADDR)
94 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
99 static struct kobj_attribute efi_attr_systab =
100 __ATTR(systab, 0400, systab_show, NULL);
102 #define EFI_FIELD(var) efi.var
104 #define EFI_ATTR_SHOW(name) \
105 static ssize_t name##_show(struct kobject *kobj, \
106 struct kobj_attribute *attr, char *buf) \
108 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
111 EFI_ATTR_SHOW(fw_vendor);
112 EFI_ATTR_SHOW(runtime);
113 EFI_ATTR_SHOW(config_table);
115 static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
116 static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
117 static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
119 static struct attribute *efi_subsys_attrs[] = {
120 &efi_attr_systab.attr,
121 &efi_attr_fw_vendor.attr,
122 &efi_attr_runtime.attr,
123 &efi_attr_config_table.attr,
127 static umode_t efi_attr_is_visible(struct kobject *kobj,
128 struct attribute *attr, int n)
130 if (attr == &efi_attr_fw_vendor.attr) {
131 if (efi_enabled(EFI_PARAVIRT) ||
132 efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
134 } else if (attr == &efi_attr_runtime.attr) {
135 if (efi.runtime == EFI_INVALID_TABLE_ADDR)
137 } else if (attr == &efi_attr_config_table.attr) {
138 if (efi.config_table == EFI_INVALID_TABLE_ADDR)
145 static struct attribute_group efi_subsys_attr_group = {
146 .attrs = efi_subsys_attrs,
147 .is_visible = efi_attr_is_visible,
150 static struct efivars generic_efivars;
151 static struct efivar_operations generic_ops;
153 static int generic_ops_register(void)
155 generic_ops.get_variable = efi.get_variable;
156 generic_ops.set_variable = efi.set_variable;
157 generic_ops.get_next_variable = efi.get_next_variable;
158 generic_ops.query_variable_store = efi_query_variable_store;
160 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
163 static void generic_ops_unregister(void)
165 efivars_unregister(&generic_efivars);
169 * We register the efi subsystem with the firmware subsystem and the
170 * efivars subsystem with the efi subsystem, if the system was booted with
173 static int __init efisubsys_init(void)
177 if (!efi_enabled(EFI_BOOT))
180 /* We register the efi directory at /sys/firmware/efi */
181 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
183 pr_err("efi: Firmware registration failed.\n");
187 error = generic_ops_register();
191 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
193 pr_err("efi: Sysfs attribute export failed with error %d.\n",
198 error = efi_runtime_map_init(efi_kobj);
200 goto err_remove_group;
202 /* and the standard mountpoint for efivarfs */
203 efivars_kobj = kobject_create_and_add("efivars", efi_kobj);
205 pr_err("efivars: Subsystem registration failed.\n");
207 goto err_remove_group;
213 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
215 generic_ops_unregister();
217 kobject_put(efi_kobj);
221 subsys_initcall(efisubsys_init);
225 * We can't ioremap data in EFI boot services RAM, because we've already mapped
226 * it as RAM. So, look it up in the existing EFI memory map instead. Only
227 * callable after efi_enter_virtual_mode and before efi_free_boot_services.
229 void __iomem *efi_lookup_mapped_addr(u64 phys_addr)
231 struct efi_memory_map *map;
236 if (WARN_ON(!map->map))
238 for (p = map->map; p < map->map_end; p += map->desc_size) {
239 efi_memory_desc_t *md = p;
240 u64 size = md->num_pages << EFI_PAGE_SHIFT;
241 u64 end = md->phys_addr + size;
242 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
243 md->type != EFI_BOOT_SERVICES_CODE &&
244 md->type != EFI_BOOT_SERVICES_DATA)
248 if (phys_addr >= md->phys_addr && phys_addr < end) {
249 phys_addr += md->virt_addr - md->phys_addr;
250 return (__force void __iomem *)(unsigned long)phys_addr;
256 static __initdata efi_config_table_type_t common_tables[] = {
257 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
258 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
259 {HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
260 {MPS_TABLE_GUID, "MPS", &efi.mps},
261 {SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
262 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
263 {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
264 {NULL_GUID, NULL, NULL},
267 static __init int match_config_table(efi_guid_t *guid,
269 efi_config_table_type_t *table_types)
271 u8 str[EFI_VARIABLE_GUID_LEN + 1];
275 efi_guid_unparse(guid, str);
277 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
278 efi_guid_unparse(&table_types[i].guid, str);
280 if (!efi_guidcmp(*guid, table_types[i].guid)) {
281 *(table_types[i].ptr) = table;
282 pr_cont(" %s=0x%lx ",
283 table_types[i].name, table);
292 int __init efi_config_init(efi_config_table_type_t *arch_tables)
294 void *config_tables, *tablep;
297 if (efi_enabled(EFI_64BIT))
298 sz = sizeof(efi_config_table_64_t);
300 sz = sizeof(efi_config_table_32_t);
303 * Let's see what config tables the firmware passed to us.
305 config_tables = early_memremap(efi.systab->tables,
306 efi.systab->nr_tables * sz);
307 if (config_tables == NULL) {
308 pr_err("Could not map Configuration table!\n");
312 tablep = config_tables;
314 for (i = 0; i < efi.systab->nr_tables; i++) {
318 if (efi_enabled(EFI_64BIT)) {
320 guid = ((efi_config_table_64_t *)tablep)->guid;
321 table64 = ((efi_config_table_64_t *)tablep)->table;
326 pr_err("Table located above 4GB, disabling EFI.\n");
327 early_memunmap(config_tables,
328 efi.systab->nr_tables * sz);
333 guid = ((efi_config_table_32_t *)tablep)->guid;
334 table = ((efi_config_table_32_t *)tablep)->table;
337 if (!match_config_table(&guid, table, common_tables))
338 match_config_table(&guid, table, arch_tables);
343 early_memunmap(config_tables, efi.systab->nr_tables * sz);
345 set_bit(EFI_CONFIG_TABLES, &efi.flags);
350 #ifdef CONFIG_EFI_VARS_MODULE
351 static int __init efi_load_efivars(void)
353 struct platform_device *pdev;
355 if (!efi_enabled(EFI_RUNTIME_SERVICES))
358 pdev = platform_device_register_simple("efivars", 0, NULL, 0);
359 return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
361 device_initcall(efi_load_efivars);
364 #ifdef CONFIG_EFI_PARAMS_FROM_FDT
366 #define UEFI_PARAM(name, prop, field) \
370 offsetof(struct efi_fdt_params, field), \
371 FIELD_SIZEOF(struct efi_fdt_params, field) \
374 static __initdata struct {
376 const char propname[32];
380 UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
381 UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
382 UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
383 UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
384 UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
393 static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
394 int depth, void *data)
396 struct param_info *info = data;
403 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
406 for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
407 prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len);
410 dest = info->params + dt_params[i].offset;
413 val = of_read_number(prop, len / sizeof(u32));
415 if (dt_params[i].size == sizeof(u32))
421 pr_info(" %s: 0x%0*llx\n", dt_params[i].name,
422 dt_params[i].size * 2, val);
427 int __init efi_get_fdt_params(struct efi_fdt_params *params, int verbose)
429 struct param_info info;
432 pr_info("Getting EFI parameters from FDT:\n");
434 info.verbose = verbose;
436 info.params = params;
438 ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
440 pr_info("UEFI not found.\n");
442 pr_err("Can't find '%s' in device tree!\n",
443 dt_params[info.found].name);
447 #endif /* CONFIG_EFI_PARAMS_FROM_FDT */
449 static __initdata char memory_type_name[][20] = {
457 "Conventional Memory",
459 "ACPI Reclaim Memory",
466 char * __init efi_md_typeattr_format(char *buf, size_t size,
467 const efi_memory_desc_t *md)
474 if (md->type >= ARRAY_SIZE(memory_type_name))
475 type_len = snprintf(pos, size, "[type=%u", md->type);
477 type_len = snprintf(pos, size, "[%-*s",
478 (int)(sizeof(memory_type_name[0]) - 1),
479 memory_type_name[md->type]);
480 if (type_len >= size)
486 attr = md->attribute;
487 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
488 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_WP |
489 EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME))
490 snprintf(pos, size, "|attr=0x%016llx]",
491 (unsigned long long)attr);
493 snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
494 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
495 attr & EFI_MEMORY_XP ? "XP" : "",
496 attr & EFI_MEMORY_RP ? "RP" : "",
497 attr & EFI_MEMORY_WP ? "WP" : "",
498 attr & EFI_MEMORY_UCE ? "UCE" : "",
499 attr & EFI_MEMORY_WB ? "WB" : "",
500 attr & EFI_MEMORY_WT ? "WT" : "",
501 attr & EFI_MEMORY_WC ? "WC" : "",
502 attr & EFI_MEMORY_UC ? "UC" : "");