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 struct kobject *efi_kobj;
45 static struct kobject *efivars_kobj;
48 * Let's not leave out systab information that snuck into
51 static ssize_t systab_show(struct kobject *kobj,
52 struct kobj_attribute *attr, char *buf)
59 if (efi.mps != EFI_INVALID_TABLE_ADDR)
60 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
61 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
62 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
63 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
64 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
65 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
66 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
67 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
68 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
69 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
70 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
71 if (efi.uga != EFI_INVALID_TABLE_ADDR)
72 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
77 static struct kobj_attribute efi_attr_systab =
78 __ATTR(systab, 0400, systab_show, NULL);
80 #define EFI_FIELD(var) efi.var
82 #define EFI_ATTR_SHOW(name) \
83 static ssize_t name##_show(struct kobject *kobj, \
84 struct kobj_attribute *attr, char *buf) \
86 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
89 EFI_ATTR_SHOW(fw_vendor);
90 EFI_ATTR_SHOW(runtime);
91 EFI_ATTR_SHOW(config_table);
93 static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
94 static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
95 static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
97 static struct attribute *efi_subsys_attrs[] = {
98 &efi_attr_systab.attr,
99 &efi_attr_fw_vendor.attr,
100 &efi_attr_runtime.attr,
101 &efi_attr_config_table.attr,
105 static umode_t efi_attr_is_visible(struct kobject *kobj,
106 struct attribute *attr, int n)
108 if (attr == &efi_attr_fw_vendor.attr) {
109 if (efi_enabled(EFI_PARAVIRT) ||
110 efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
112 } else if (attr == &efi_attr_runtime.attr) {
113 if (efi.runtime == EFI_INVALID_TABLE_ADDR)
115 } else if (attr == &efi_attr_config_table.attr) {
116 if (efi.config_table == EFI_INVALID_TABLE_ADDR)
123 static struct attribute_group efi_subsys_attr_group = {
124 .attrs = efi_subsys_attrs,
125 .is_visible = efi_attr_is_visible,
128 static struct efivars generic_efivars;
129 static struct efivar_operations generic_ops;
131 static int generic_ops_register(void)
133 generic_ops.get_variable = efi.get_variable;
134 generic_ops.set_variable = efi.set_variable;
135 generic_ops.get_next_variable = efi.get_next_variable;
136 generic_ops.query_variable_store = efi_query_variable_store;
138 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
141 static void generic_ops_unregister(void)
143 efivars_unregister(&generic_efivars);
147 * We register the efi subsystem with the firmware subsystem and the
148 * efivars subsystem with the efi subsystem, if the system was booted with
151 static int __init efisubsys_init(void)
155 if (!efi_enabled(EFI_BOOT))
158 /* We register the efi directory at /sys/firmware/efi */
159 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
161 pr_err("efi: Firmware registration failed.\n");
165 error = generic_ops_register();
169 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
171 pr_err("efi: Sysfs attribute export failed with error %d.\n",
176 error = efi_runtime_map_init(efi_kobj);
178 goto err_remove_group;
180 /* and the standard mountpoint for efivarfs */
181 efivars_kobj = kobject_create_and_add("efivars", efi_kobj);
183 pr_err("efivars: Subsystem registration failed.\n");
185 goto err_remove_group;
191 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
193 generic_ops_unregister();
195 kobject_put(efi_kobj);
199 subsys_initcall(efisubsys_init);
203 * We can't ioremap data in EFI boot services RAM, because we've already mapped
204 * it as RAM. So, look it up in the existing EFI memory map instead. Only
205 * callable after efi_enter_virtual_mode and before efi_free_boot_services.
207 void __iomem *efi_lookup_mapped_addr(u64 phys_addr)
209 struct efi_memory_map *map;
214 if (WARN_ON(!map->map))
216 for (p = map->map; p < map->map_end; p += map->desc_size) {
217 efi_memory_desc_t *md = p;
218 u64 size = md->num_pages << EFI_PAGE_SHIFT;
219 u64 end = md->phys_addr + size;
220 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
221 md->type != EFI_BOOT_SERVICES_CODE &&
222 md->type != EFI_BOOT_SERVICES_DATA)
226 if (phys_addr >= md->phys_addr && phys_addr < end) {
227 phys_addr += md->virt_addr - md->phys_addr;
228 return (__force void __iomem *)(unsigned long)phys_addr;
234 static __initdata efi_config_table_type_t common_tables[] = {
235 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
236 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
237 {HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
238 {MPS_TABLE_GUID, "MPS", &efi.mps},
239 {SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
240 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
241 {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
242 {NULL_GUID, NULL, NULL},
245 static __init int match_config_table(efi_guid_t *guid,
247 efi_config_table_type_t *table_types)
249 u8 str[EFI_VARIABLE_GUID_LEN + 1];
253 efi_guid_unparse(guid, str);
255 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
256 efi_guid_unparse(&table_types[i].guid, str);
258 if (!efi_guidcmp(*guid, table_types[i].guid)) {
259 *(table_types[i].ptr) = table;
260 pr_cont(" %s=0x%lx ",
261 table_types[i].name, table);
270 int __init efi_config_init(efi_config_table_type_t *arch_tables)
272 void *config_tables, *tablep;
275 if (efi_enabled(EFI_64BIT))
276 sz = sizeof(efi_config_table_64_t);
278 sz = sizeof(efi_config_table_32_t);
281 * Let's see what config tables the firmware passed to us.
283 config_tables = early_memremap(efi.systab->tables,
284 efi.systab->nr_tables * sz);
285 if (config_tables == NULL) {
286 pr_err("Could not map Configuration table!\n");
290 tablep = config_tables;
292 for (i = 0; i < efi.systab->nr_tables; i++) {
296 if (efi_enabled(EFI_64BIT)) {
298 guid = ((efi_config_table_64_t *)tablep)->guid;
299 table64 = ((efi_config_table_64_t *)tablep)->table;
304 pr_err("Table located above 4GB, disabling EFI.\n");
305 early_memunmap(config_tables,
306 efi.systab->nr_tables * sz);
311 guid = ((efi_config_table_32_t *)tablep)->guid;
312 table = ((efi_config_table_32_t *)tablep)->table;
315 if (!match_config_table(&guid, table, common_tables))
316 match_config_table(&guid, table, arch_tables);
321 early_memunmap(config_tables, efi.systab->nr_tables * sz);
323 set_bit(EFI_CONFIG_TABLES, &efi.flags);
328 #ifdef CONFIG_EFI_VARS_MODULE
329 static int __init efi_load_efivars(void)
331 struct platform_device *pdev;
333 if (!efi_enabled(EFI_RUNTIME_SERVICES))
336 pdev = platform_device_register_simple("efivars", 0, NULL, 0);
337 return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
339 device_initcall(efi_load_efivars);
342 #ifdef CONFIG_EFI_PARAMS_FROM_FDT
344 #define UEFI_PARAM(name, prop, field) \
348 offsetof(struct efi_fdt_params, field), \
349 FIELD_SIZEOF(struct efi_fdt_params, field) \
352 static __initdata struct {
354 const char propname[32];
358 UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
359 UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
360 UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
361 UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
362 UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
371 static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
372 int depth, void *data)
374 struct param_info *info = data;
381 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
384 for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
385 prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len);
388 dest = info->params + dt_params[i].offset;
391 val = of_read_number(prop, len / sizeof(u32));
393 if (dt_params[i].size == sizeof(u32))
399 pr_info(" %s: 0x%0*llx\n", dt_params[i].name,
400 dt_params[i].size * 2, val);
405 int __init efi_get_fdt_params(struct efi_fdt_params *params, int verbose)
407 struct param_info info;
410 pr_info("Getting EFI parameters from FDT:\n");
412 info.verbose = verbose;
414 info.params = params;
416 ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
418 pr_info("UEFI not found.\n");
420 pr_err("Can't find '%s' in device tree!\n",
421 dt_params[info.found].name);
425 #endif /* CONFIG_EFI_PARAMS_FROM_FDT */