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Tom Gundersena9499fa2013-02-08 15:37:06 +00001/*
2 * efi.c - EFI subsystem
3 *
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>
7 *
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.
12 *
13 * This file is released under the GPLv2.
14 */
15
Leif Lindholm272686b2013-09-05 11:34:54 +010016#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
Tom Gundersena9499fa2013-02-08 15:37:06 +000018#include <linux/kobject.h>
19#include <linux/module.h>
20#include <linux/init.h>
21#include <linux/device.h>
22#include <linux/efi.h>
Leif Lindholm272686b2013-09-05 11:34:54 +010023#include <linux/io.h>
24
25struct efi __read_mostly efi = {
26 .mps = EFI_INVALID_TABLE_ADDR,
27 .acpi = EFI_INVALID_TABLE_ADDR,
28 .acpi20 = EFI_INVALID_TABLE_ADDR,
29 .smbios = EFI_INVALID_TABLE_ADDR,
30 .sal_systab = EFI_INVALID_TABLE_ADDR,
31 .boot_info = EFI_INVALID_TABLE_ADDR,
32 .hcdp = EFI_INVALID_TABLE_ADDR,
33 .uga = EFI_INVALID_TABLE_ADDR,
34 .uv_systab = EFI_INVALID_TABLE_ADDR,
Dave Younga0998eb2013-12-20 18:02:17 +080035 .fw_vendor = EFI_INVALID_TABLE_ADDR,
36 .runtime = EFI_INVALID_TABLE_ADDR,
37 .config_table = EFI_INVALID_TABLE_ADDR,
Leif Lindholm272686b2013-09-05 11:34:54 +010038};
39EXPORT_SYMBOL(efi);
Tom Gundersena9499fa2013-02-08 15:37:06 +000040
41static struct kobject *efi_kobj;
42static struct kobject *efivars_kobj;
43
44/*
45 * Let's not leave out systab information that snuck into
46 * the efivars driver
47 */
48static ssize_t systab_show(struct kobject *kobj,
49 struct kobj_attribute *attr, char *buf)
50{
51 char *str = buf;
52
53 if (!kobj || !buf)
54 return -EINVAL;
55
56 if (efi.mps != EFI_INVALID_TABLE_ADDR)
57 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
58 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
59 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
60 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
61 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
62 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
63 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
64 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
65 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
66 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
67 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
68 if (efi.uga != EFI_INVALID_TABLE_ADDR)
69 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
70
71 return str - buf;
72}
73
74static struct kobj_attribute efi_attr_systab =
75 __ATTR(systab, 0400, systab_show, NULL);
76
Dave Younga0998eb2013-12-20 18:02:17 +080077#define EFI_FIELD(var) efi.var
78
79#define EFI_ATTR_SHOW(name) \
80static ssize_t name##_show(struct kobject *kobj, \
81 struct kobj_attribute *attr, char *buf) \
82{ \
83 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
84}
85
86EFI_ATTR_SHOW(fw_vendor);
87EFI_ATTR_SHOW(runtime);
88EFI_ATTR_SHOW(config_table);
89
90static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
91static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
92static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
93
Tom Gundersena9499fa2013-02-08 15:37:06 +000094static struct attribute *efi_subsys_attrs[] = {
95 &efi_attr_systab.attr,
Dave Younga0998eb2013-12-20 18:02:17 +080096 &efi_attr_fw_vendor.attr,
97 &efi_attr_runtime.attr,
98 &efi_attr_config_table.attr,
99 NULL,
Tom Gundersena9499fa2013-02-08 15:37:06 +0000100};
101
Dave Younga0998eb2013-12-20 18:02:17 +0800102static umode_t efi_attr_is_visible(struct kobject *kobj,
103 struct attribute *attr, int n)
104{
105 umode_t mode = attr->mode;
106
107 if (attr == &efi_attr_fw_vendor.attr)
108 return (efi.fw_vendor == EFI_INVALID_TABLE_ADDR) ? 0 : mode;
109 else if (attr == &efi_attr_runtime.attr)
110 return (efi.runtime == EFI_INVALID_TABLE_ADDR) ? 0 : mode;
111 else if (attr == &efi_attr_config_table.attr)
112 return (efi.config_table == EFI_INVALID_TABLE_ADDR) ? 0 : mode;
113
114 return mode;
115}
116
Tom Gundersena9499fa2013-02-08 15:37:06 +0000117static struct attribute_group efi_subsys_attr_group = {
118 .attrs = efi_subsys_attrs,
Dave Younga0998eb2013-12-20 18:02:17 +0800119 .is_visible = efi_attr_is_visible,
Tom Gundersena9499fa2013-02-08 15:37:06 +0000120};
121
122static struct efivars generic_efivars;
123static struct efivar_operations generic_ops;
124
125static int generic_ops_register(void)
126{
127 generic_ops.get_variable = efi.get_variable;
128 generic_ops.set_variable = efi.set_variable;
129 generic_ops.get_next_variable = efi.get_next_variable;
Matt Fleminga614e192013-04-30 11:30:24 +0100130 generic_ops.query_variable_store = efi_query_variable_store;
Tom Gundersena9499fa2013-02-08 15:37:06 +0000131
132 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
133}
134
135static void generic_ops_unregister(void)
136{
137 efivars_unregister(&generic_efivars);
138}
139
140/*
141 * We register the efi subsystem with the firmware subsystem and the
142 * efivars subsystem with the efi subsystem, if the system was booted with
143 * EFI.
144 */
145static int __init efisubsys_init(void)
146{
147 int error;
148
149 if (!efi_enabled(EFI_BOOT))
150 return 0;
151
152 /* We register the efi directory at /sys/firmware/efi */
153 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
154 if (!efi_kobj) {
155 pr_err("efi: Firmware registration failed.\n");
156 return -ENOMEM;
157 }
158
159 error = generic_ops_register();
160 if (error)
161 goto err_put;
162
163 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
164 if (error) {
165 pr_err("efi: Sysfs attribute export failed with error %d.\n",
166 error);
167 goto err_unregister;
168 }
169
Dave Young926172d2013-12-20 18:02:18 +0800170 error = efi_runtime_map_init(efi_kobj);
171 if (error)
172 goto err_remove_group;
173
Tom Gundersena9499fa2013-02-08 15:37:06 +0000174 /* and the standard mountpoint for efivarfs */
175 efivars_kobj = kobject_create_and_add("efivars", efi_kobj);
176 if (!efivars_kobj) {
177 pr_err("efivars: Subsystem registration failed.\n");
178 error = -ENOMEM;
179 goto err_remove_group;
180 }
181
182 return 0;
183
184err_remove_group:
185 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
186err_unregister:
187 generic_ops_unregister();
188err_put:
189 kobject_put(efi_kobj);
190 return error;
191}
192
193subsys_initcall(efisubsys_init);
Leif Lindholm272686b2013-09-05 11:34:54 +0100194
195
Leif Lindholm258f6fd2013-09-05 11:34:55 +0100196/*
197 * We can't ioremap data in EFI boot services RAM, because we've already mapped
198 * it as RAM. So, look it up in the existing EFI memory map instead. Only
199 * callable after efi_enter_virtual_mode and before efi_free_boot_services.
200 */
201void __iomem *efi_lookup_mapped_addr(u64 phys_addr)
202{
203 struct efi_memory_map *map;
204 void *p;
205 map = efi.memmap;
206 if (!map)
207 return NULL;
208 if (WARN_ON(!map->map))
209 return NULL;
210 for (p = map->map; p < map->map_end; p += map->desc_size) {
211 efi_memory_desc_t *md = p;
212 u64 size = md->num_pages << EFI_PAGE_SHIFT;
213 u64 end = md->phys_addr + size;
214 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
215 md->type != EFI_BOOT_SERVICES_CODE &&
216 md->type != EFI_BOOT_SERVICES_DATA)
217 continue;
218 if (!md->virt_addr)
219 continue;
220 if (phys_addr >= md->phys_addr && phys_addr < end) {
221 phys_addr += md->virt_addr - md->phys_addr;
222 return (__force void __iomem *)(unsigned long)phys_addr;
223 }
224 }
225 return NULL;
226}
227
Leif Lindholm272686b2013-09-05 11:34:54 +0100228static __initdata efi_config_table_type_t common_tables[] = {
229 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
230 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
231 {HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
232 {MPS_TABLE_GUID, "MPS", &efi.mps},
233 {SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
234 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
235 {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
Daeseok Youn69e60842014-02-13 17:16:36 +0900236 {NULL_GUID, NULL, NULL},
Leif Lindholm272686b2013-09-05 11:34:54 +0100237};
238
239static __init int match_config_table(efi_guid_t *guid,
240 unsigned long table,
241 efi_config_table_type_t *table_types)
242{
243 u8 str[EFI_VARIABLE_GUID_LEN + 1];
244 int i;
245
246 if (table_types) {
247 efi_guid_unparse(guid, str);
248
249 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
250 efi_guid_unparse(&table_types[i].guid, str);
251
252 if (!efi_guidcmp(*guid, table_types[i].guid)) {
253 *(table_types[i].ptr) = table;
254 pr_cont(" %s=0x%lx ",
255 table_types[i].name, table);
256 return 1;
257 }
258 }
259 }
260
261 return 0;
262}
263
264int __init efi_config_init(efi_config_table_type_t *arch_tables)
265{
266 void *config_tables, *tablep;
267 int i, sz;
268
269 if (efi_enabled(EFI_64BIT))
270 sz = sizeof(efi_config_table_64_t);
271 else
272 sz = sizeof(efi_config_table_32_t);
273
274 /*
275 * Let's see what config tables the firmware passed to us.
276 */
277 config_tables = early_memremap(efi.systab->tables,
278 efi.systab->nr_tables * sz);
279 if (config_tables == NULL) {
280 pr_err("Could not map Configuration table!\n");
281 return -ENOMEM;
282 }
283
284 tablep = config_tables;
285 pr_info("");
286 for (i = 0; i < efi.systab->nr_tables; i++) {
287 efi_guid_t guid;
288 unsigned long table;
289
290 if (efi_enabled(EFI_64BIT)) {
291 u64 table64;
292 guid = ((efi_config_table_64_t *)tablep)->guid;
293 table64 = ((efi_config_table_64_t *)tablep)->table;
294 table = table64;
295#ifndef CONFIG_64BIT
296 if (table64 >> 32) {
297 pr_cont("\n");
298 pr_err("Table located above 4GB, disabling EFI.\n");
299 early_iounmap(config_tables,
300 efi.systab->nr_tables * sz);
301 return -EINVAL;
302 }
303#endif
304 } else {
305 guid = ((efi_config_table_32_t *)tablep)->guid;
306 table = ((efi_config_table_32_t *)tablep)->table;
307 }
308
309 if (!match_config_table(&guid, table, common_tables))
310 match_config_table(&guid, table, arch_tables);
311
312 tablep += sz;
313 }
314 pr_cont("\n");
315 early_iounmap(config_tables, efi.systab->nr_tables * sz);
Matt Fleming0f8093a2014-01-15 13:36:33 +0000316
317 set_bit(EFI_CONFIG_TABLES, &efi.flags);
318
Leif Lindholm272686b2013-09-05 11:34:54 +0100319 return 0;
320}