1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * efi.c - EFI subsystem
4 *
5 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
6 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
7 * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
8 *
9 * This code registers /sys/firmware/efi{,/efivars} when EFI is supported,
10 * allowing the efivarfs to be mounted or the efivars module to be loaded.
11 * The existance of /sys/firmware/efi may also be used by userspace to
12 * determine that the system supports EFI.
13 */
14
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16
17 #include <linux/kobject.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/debugfs.h>
21 #include <linux/device.h>
22 #include <linux/efi.h>
23 #include <linux/of.h>
24 #include <linux/io.h>
25 #include <linux/kexec.h>
26 #include <linux/platform_device.h>
27 #include <linux/random.h>
28 #include <linux/reboot.h>
29 #include <linux/slab.h>
30 #include <linux/acpi.h>
31 #include <linux/ucs2_string.h>
32 #include <linux/memblock.h>
33 #include <linux/security.h>
34
35 #include <asm/early_ioremap.h>
36
37 struct efi __read_mostly efi = {
38 .runtime_supported_mask = EFI_RT_SUPPORTED_ALL,
39 .acpi = EFI_INVALID_TABLE_ADDR,
40 .acpi20 = EFI_INVALID_TABLE_ADDR,
41 .smbios = EFI_INVALID_TABLE_ADDR,
42 .smbios3 = EFI_INVALID_TABLE_ADDR,
43 .esrt = EFI_INVALID_TABLE_ADDR,
44 .tpm_log = EFI_INVALID_TABLE_ADDR,
45 .tpm_final_log = EFI_INVALID_TABLE_ADDR,
46 #ifdef CONFIG_LOAD_UEFI_KEYS
47 .mokvar_table = EFI_INVALID_TABLE_ADDR,
48 #endif
49 #ifdef CONFIG_EFI_COCO_SECRET
50 .coco_secret = EFI_INVALID_TABLE_ADDR,
51 #endif
52 };
53 EXPORT_SYMBOL(efi);
54
55 unsigned long __ro_after_init efi_rng_seed = EFI_INVALID_TABLE_ADDR;
56 static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR;
57 static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR;
58
59 struct mm_struct efi_mm = {
60 .mm_rb = RB_ROOT,
61 .mm_users = ATOMIC_INIT(2),
62 .mm_count = ATOMIC_INIT(1),
63 .write_protect_seq = SEQCNT_ZERO(efi_mm.write_protect_seq),
64 MMAP_LOCK_INITIALIZER(efi_mm)
65 .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
66 .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
67 .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0},
68 };
69
70 struct workqueue_struct *efi_rts_wq;
71
72 static bool disable_runtime = IS_ENABLED(CONFIG_EFI_DISABLE_RUNTIME);
setup_noefi(char * arg)73 static int __init setup_noefi(char *arg)
74 {
75 disable_runtime = true;
76 return 0;
77 }
78 early_param("noefi", setup_noefi);
79
efi_runtime_disabled(void)80 bool efi_runtime_disabled(void)
81 {
82 return disable_runtime;
83 }
84
__efi_soft_reserve_enabled(void)85 bool __pure __efi_soft_reserve_enabled(void)
86 {
87 return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE);
88 }
89
parse_efi_cmdline(char * str)90 static int __init parse_efi_cmdline(char *str)
91 {
92 if (!str) {
93 pr_warn("need at least one option\n");
94 return -EINVAL;
95 }
96
97 if (parse_option_str(str, "debug"))
98 set_bit(EFI_DBG, &efi.flags);
99
100 if (parse_option_str(str, "noruntime"))
101 disable_runtime = true;
102
103 if (parse_option_str(str, "runtime"))
104 disable_runtime = false;
105
106 if (parse_option_str(str, "nosoftreserve"))
107 set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags);
108
109 return 0;
110 }
111 early_param("efi", parse_efi_cmdline);
112
113 struct kobject *efi_kobj;
114
115 /*
116 * Let's not leave out systab information that snuck into
117 * the efivars driver
118 * Note, do not add more fields in systab sysfs file as it breaks sysfs
119 * one value per file rule!
120 */
systab_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)121 static ssize_t systab_show(struct kobject *kobj,
122 struct kobj_attribute *attr, char *buf)
123 {
124 char *str = buf;
125
126 if (!kobj || !buf)
127 return -EINVAL;
128
129 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
130 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
131 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
132 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
133 /*
134 * If both SMBIOS and SMBIOS3 entry points are implemented, the
135 * SMBIOS3 entry point shall be preferred, so we list it first to
136 * let applications stop parsing after the first match.
137 */
138 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
139 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
140 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
141 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
142
143 if (IS_ENABLED(CONFIG_IA64) || IS_ENABLED(CONFIG_X86))
144 str = efi_systab_show_arch(str);
145
146 return str - buf;
147 }
148
149 static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
150
fw_platform_size_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)151 static ssize_t fw_platform_size_show(struct kobject *kobj,
152 struct kobj_attribute *attr, char *buf)
153 {
154 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
155 }
156
157 extern __weak struct kobj_attribute efi_attr_fw_vendor;
158 extern __weak struct kobj_attribute efi_attr_runtime;
159 extern __weak struct kobj_attribute efi_attr_config_table;
160 static struct kobj_attribute efi_attr_fw_platform_size =
161 __ATTR_RO(fw_platform_size);
162
163 static struct attribute *efi_subsys_attrs[] = {
164 &efi_attr_systab.attr,
165 &efi_attr_fw_platform_size.attr,
166 &efi_attr_fw_vendor.attr,
167 &efi_attr_runtime.attr,
168 &efi_attr_config_table.attr,
169 NULL,
170 };
171
efi_attr_is_visible(struct kobject * kobj,struct attribute * attr,int n)172 umode_t __weak efi_attr_is_visible(struct kobject *kobj, struct attribute *attr,
173 int n)
174 {
175 return attr->mode;
176 }
177
178 static const struct attribute_group efi_subsys_attr_group = {
179 .attrs = efi_subsys_attrs,
180 .is_visible = efi_attr_is_visible,
181 };
182
183 static struct efivars generic_efivars;
184 static struct efivar_operations generic_ops;
185
generic_ops_register(void)186 static int generic_ops_register(void)
187 {
188 generic_ops.get_variable = efi.get_variable;
189 generic_ops.get_next_variable = efi.get_next_variable;
190 generic_ops.query_variable_store = efi_query_variable_store;
191
192 if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) {
193 generic_ops.set_variable = efi.set_variable;
194 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
195 }
196 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
197 }
198
generic_ops_unregister(void)199 static void generic_ops_unregister(void)
200 {
201 efivars_unregister(&generic_efivars);
202 }
203
204 #ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS
205 #define EFIVAR_SSDT_NAME_MAX 16
206 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
efivar_ssdt_setup(char * str)207 static int __init efivar_ssdt_setup(char *str)
208 {
209 int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
210
211 if (ret)
212 return ret;
213
214 if (strlen(str) < sizeof(efivar_ssdt))
215 memcpy(efivar_ssdt, str, strlen(str));
216 else
217 pr_warn("efivar_ssdt: name too long: %s\n", str);
218 return 1;
219 }
220 __setup("efivar_ssdt=", efivar_ssdt_setup);
221
efivar_ssdt_iter(efi_char16_t * name,efi_guid_t vendor,unsigned long name_size,void * data)222 static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
223 unsigned long name_size, void *data)
224 {
225 struct efivar_entry *entry;
226 struct list_head *list = data;
227 char utf8_name[EFIVAR_SSDT_NAME_MAX];
228 int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
229
230 ucs2_as_utf8(utf8_name, name, limit - 1);
231 if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
232 return 0;
233
234 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
235 if (!entry)
236 return 0;
237
238 memcpy(entry->var.VariableName, name, name_size);
239 memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
240
241 efivar_entry_add(entry, list);
242
243 return 0;
244 }
245
efivar_ssdt_load(void)246 static __init int efivar_ssdt_load(void)
247 {
248 LIST_HEAD(entries);
249 struct efivar_entry *entry, *aux;
250 unsigned long size;
251 void *data;
252 int ret;
253
254 if (!efivar_ssdt[0])
255 return 0;
256
257 ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
258
259 list_for_each_entry_safe(entry, aux, &entries, list) {
260 pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
261 &entry->var.VendorGuid);
262
263 list_del(&entry->list);
264
265 ret = efivar_entry_size(entry, &size);
266 if (ret) {
267 pr_err("failed to get var size\n");
268 goto free_entry;
269 }
270
271 data = kmalloc(size, GFP_KERNEL);
272 if (!data) {
273 ret = -ENOMEM;
274 goto free_entry;
275 }
276
277 ret = efivar_entry_get(entry, NULL, &size, data);
278 if (ret) {
279 pr_err("failed to get var data\n");
280 goto free_data;
281 }
282
283 ret = acpi_load_table(data, NULL);
284 if (ret) {
285 pr_err("failed to load table: %d\n", ret);
286 goto free_data;
287 }
288
289 goto free_entry;
290
291 free_data:
292 kfree(data);
293
294 free_entry:
295 kfree(entry);
296 }
297
298 return ret;
299 }
300 #else
efivar_ssdt_load(void)301 static inline int efivar_ssdt_load(void) { return 0; }
302 #endif
303
304 #ifdef CONFIG_DEBUG_FS
305
306 #define EFI_DEBUGFS_MAX_BLOBS 32
307
308 static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS];
309
efi_debugfs_init(void)310 static void __init efi_debugfs_init(void)
311 {
312 struct dentry *efi_debugfs;
313 efi_memory_desc_t *md;
314 char name[32];
315 int type_count[EFI_BOOT_SERVICES_DATA + 1] = {};
316 int i = 0;
317
318 efi_debugfs = debugfs_create_dir("efi", NULL);
319 if (IS_ERR_OR_NULL(efi_debugfs))
320 return;
321
322 for_each_efi_memory_desc(md) {
323 switch (md->type) {
324 case EFI_BOOT_SERVICES_CODE:
325 snprintf(name, sizeof(name), "boot_services_code%d",
326 type_count[md->type]++);
327 break;
328 case EFI_BOOT_SERVICES_DATA:
329 snprintf(name, sizeof(name), "boot_services_data%d",
330 type_count[md->type]++);
331 break;
332 default:
333 continue;
334 }
335
336 if (i >= EFI_DEBUGFS_MAX_BLOBS) {
337 pr_warn("More then %d EFI boot service segments, only showing first %d in debugfs\n",
338 EFI_DEBUGFS_MAX_BLOBS, EFI_DEBUGFS_MAX_BLOBS);
339 break;
340 }
341
342 debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT;
343 debugfs_blob[i].data = memremap(md->phys_addr,
344 debugfs_blob[i].size,
345 MEMREMAP_WB);
346 if (!debugfs_blob[i].data)
347 continue;
348
349 debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]);
350 i++;
351 }
352 }
353 #else
efi_debugfs_init(void)354 static inline void efi_debugfs_init(void) {}
355 #endif
356
357 /*
358 * We register the efi subsystem with the firmware subsystem and the
359 * efivars subsystem with the efi subsystem, if the system was booted with
360 * EFI.
361 */
efisubsys_init(void)362 static int __init efisubsys_init(void)
363 {
364 int error;
365
366 if (!efi_enabled(EFI_RUNTIME_SERVICES))
367 efi.runtime_supported_mask = 0;
368
369 if (!efi_enabled(EFI_BOOT))
370 return 0;
371
372 if (efi.runtime_supported_mask) {
373 /*
374 * Since we process only one efi_runtime_service() at a time, an
375 * ordered workqueue (which creates only one execution context)
376 * should suffice for all our needs.
377 */
378 efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
379 if (!efi_rts_wq) {
380 pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
381 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
382 efi.runtime_supported_mask = 0;
383 return 0;
384 }
385 }
386
387 if (efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES))
388 platform_device_register_simple("rtc-efi", 0, NULL, 0);
389
390 /* We register the efi directory at /sys/firmware/efi */
391 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
392 if (!efi_kobj) {
393 pr_err("efi: Firmware registration failed.\n");
394 destroy_workqueue(efi_rts_wq);
395 return -ENOMEM;
396 }
397
398 if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
399 EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) {
400 error = generic_ops_register();
401 if (error)
402 goto err_put;
403 efivar_ssdt_load();
404 platform_device_register_simple("efivars", 0, NULL, 0);
405 }
406
407 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
408 if (error) {
409 pr_err("efi: Sysfs attribute export failed with error %d.\n",
410 error);
411 goto err_unregister;
412 }
413
414 error = efi_runtime_map_init(efi_kobj);
415 if (error)
416 goto err_remove_group;
417
418 /* and the standard mountpoint for efivarfs */
419 error = sysfs_create_mount_point(efi_kobj, "efivars");
420 if (error) {
421 pr_err("efivars: Subsystem registration failed.\n");
422 goto err_remove_group;
423 }
424
425 if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
426 efi_debugfs_init();
427
428 #ifdef CONFIG_EFI_COCO_SECRET
429 if (efi.coco_secret != EFI_INVALID_TABLE_ADDR)
430 platform_device_register_simple("efi_secret", 0, NULL, 0);
431 #endif
432
433 return 0;
434
435 err_remove_group:
436 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
437 err_unregister:
438 if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
439 EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME))
440 generic_ops_unregister();
441 err_put:
442 kobject_put(efi_kobj);
443 destroy_workqueue(efi_rts_wq);
444 return error;
445 }
446
447 subsys_initcall(efisubsys_init);
448
449 /*
450 * Find the efi memory descriptor for a given physical address. Given a
451 * physical address, determine if it exists within an EFI Memory Map entry,
452 * and if so, populate the supplied memory descriptor with the appropriate
453 * data.
454 */
efi_mem_desc_lookup(u64 phys_addr,efi_memory_desc_t * out_md)455 int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
456 {
457 efi_memory_desc_t *md;
458
459 if (!efi_enabled(EFI_MEMMAP)) {
460 pr_err_once("EFI_MEMMAP is not enabled.\n");
461 return -EINVAL;
462 }
463
464 if (!out_md) {
465 pr_err_once("out_md is null.\n");
466 return -EINVAL;
467 }
468
469 for_each_efi_memory_desc(md) {
470 u64 size;
471 u64 end;
472
473 size = md->num_pages << EFI_PAGE_SHIFT;
474 end = md->phys_addr + size;
475 if (phys_addr >= md->phys_addr && phys_addr < end) {
476 memcpy(out_md, md, sizeof(*out_md));
477 return 0;
478 }
479 }
480 return -ENOENT;
481 }
482
483 /*
484 * Calculate the highest address of an efi memory descriptor.
485 */
efi_mem_desc_end(efi_memory_desc_t * md)486 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
487 {
488 u64 size = md->num_pages << EFI_PAGE_SHIFT;
489 u64 end = md->phys_addr + size;
490 return end;
491 }
492
efi_arch_mem_reserve(phys_addr_t addr,u64 size)493 void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
494
495 /**
496 * efi_mem_reserve - Reserve an EFI memory region
497 * @addr: Physical address to reserve
498 * @size: Size of reservation
499 *
500 * Mark a region as reserved from general kernel allocation and
501 * prevent it being released by efi_free_boot_services().
502 *
503 * This function should be called drivers once they've parsed EFI
504 * configuration tables to figure out where their data lives, e.g.
505 * efi_esrt_init().
506 */
efi_mem_reserve(phys_addr_t addr,u64 size)507 void __init efi_mem_reserve(phys_addr_t addr, u64 size)
508 {
509 if (!memblock_is_region_reserved(addr, size))
510 memblock_reserve(addr, size);
511
512 /*
513 * Some architectures (x86) reserve all boot services ranges
514 * until efi_free_boot_services() because of buggy firmware
515 * implementations. This means the above memblock_reserve() is
516 * superfluous on x86 and instead what it needs to do is
517 * ensure the @start, @size is not freed.
518 */
519 efi_arch_mem_reserve(addr, size);
520 }
521
522 static const efi_config_table_type_t common_tables[] __initconst = {
523 {ACPI_20_TABLE_GUID, &efi.acpi20, "ACPI 2.0" },
524 {ACPI_TABLE_GUID, &efi.acpi, "ACPI" },
525 {SMBIOS_TABLE_GUID, &efi.smbios, "SMBIOS" },
526 {SMBIOS3_TABLE_GUID, &efi.smbios3, "SMBIOS 3.0" },
527 {EFI_SYSTEM_RESOURCE_TABLE_GUID, &efi.esrt, "ESRT" },
528 {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, &efi_mem_attr_table, "MEMATTR" },
529 {LINUX_EFI_RANDOM_SEED_TABLE_GUID, &efi_rng_seed, "RNG" },
530 {LINUX_EFI_TPM_EVENT_LOG_GUID, &efi.tpm_log, "TPMEventLog" },
531 {LINUX_EFI_TPM_FINAL_LOG_GUID, &efi.tpm_final_log, "TPMFinalLog" },
532 {LINUX_EFI_MEMRESERVE_TABLE_GUID, &mem_reserve, "MEMRESERVE" },
533 {EFI_RT_PROPERTIES_TABLE_GUID, &rt_prop, "RTPROP" },
534 #ifdef CONFIG_EFI_RCI2_TABLE
535 {DELLEMC_EFI_RCI2_TABLE_GUID, &rci2_table_phys },
536 #endif
537 #ifdef CONFIG_LOAD_UEFI_KEYS
538 {LINUX_EFI_MOK_VARIABLE_TABLE_GUID, &efi.mokvar_table, "MOKvar" },
539 #endif
540 #ifdef CONFIG_EFI_COCO_SECRET
541 {LINUX_EFI_COCO_SECRET_AREA_GUID, &efi.coco_secret, "CocoSecret" },
542 #endif
543 {},
544 };
545
match_config_table(const efi_guid_t * guid,unsigned long table,const efi_config_table_type_t * table_types)546 static __init int match_config_table(const efi_guid_t *guid,
547 unsigned long table,
548 const efi_config_table_type_t *table_types)
549 {
550 int i;
551
552 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
553 if (!efi_guidcmp(*guid, table_types[i].guid)) {
554 *(table_types[i].ptr) = table;
555 if (table_types[i].name[0])
556 pr_cont("%s=0x%lx ",
557 table_types[i].name, table);
558 return 1;
559 }
560 }
561
562 return 0;
563 }
564
efi_config_parse_tables(const efi_config_table_t * config_tables,int count,const efi_config_table_type_t * arch_tables)565 int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
566 int count,
567 const efi_config_table_type_t *arch_tables)
568 {
569 const efi_config_table_64_t *tbl64 = (void *)config_tables;
570 const efi_config_table_32_t *tbl32 = (void *)config_tables;
571 const efi_guid_t *guid;
572 unsigned long table;
573 int i;
574
575 pr_info("");
576 for (i = 0; i < count; i++) {
577 if (!IS_ENABLED(CONFIG_X86)) {
578 guid = &config_tables[i].guid;
579 table = (unsigned long)config_tables[i].table;
580 } else if (efi_enabled(EFI_64BIT)) {
581 guid = &tbl64[i].guid;
582 table = tbl64[i].table;
583
584 if (IS_ENABLED(CONFIG_X86_32) &&
585 tbl64[i].table > U32_MAX) {
586 pr_cont("\n");
587 pr_err("Table located above 4GB, disabling EFI.\n");
588 return -EINVAL;
589 }
590 } else {
591 guid = &tbl32[i].guid;
592 table = tbl32[i].table;
593 }
594
595 if (!match_config_table(guid, table, common_tables) && arch_tables)
596 match_config_table(guid, table, arch_tables);
597 }
598 pr_cont("\n");
599 set_bit(EFI_CONFIG_TABLES, &efi.flags);
600
601 if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) {
602 struct linux_efi_random_seed *seed;
603 u32 size = 0;
604
605 seed = early_memremap(efi_rng_seed, sizeof(*seed));
606 if (seed != NULL) {
607 size = READ_ONCE(seed->size);
608 early_memunmap(seed, sizeof(*seed));
609 } else {
610 pr_err("Could not map UEFI random seed!\n");
611 }
612 if (size > 0) {
613 seed = early_memremap(efi_rng_seed,
614 sizeof(*seed) + size);
615 if (seed != NULL) {
616 pr_notice("seeding entropy pool\n");
617 add_bootloader_randomness(seed->bits, size);
618 early_memunmap(seed, sizeof(*seed) + size);
619 } else {
620 pr_err("Could not map UEFI random seed!\n");
621 }
622 }
623 }
624
625 if (!IS_ENABLED(CONFIG_X86_32) && efi_enabled(EFI_MEMMAP))
626 efi_memattr_init();
627
628 efi_tpm_eventlog_init();
629
630 if (mem_reserve != EFI_INVALID_TABLE_ADDR) {
631 unsigned long prsv = mem_reserve;
632
633 while (prsv) {
634 struct linux_efi_memreserve *rsv;
635 u8 *p;
636
637 /*
638 * Just map a full page: that is what we will get
639 * anyway, and it permits us to map the entire entry
640 * before knowing its size.
641 */
642 p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
643 PAGE_SIZE);
644 if (p == NULL) {
645 pr_err("Could not map UEFI memreserve entry!\n");
646 return -ENOMEM;
647 }
648
649 rsv = (void *)(p + prsv % PAGE_SIZE);
650
651 /* reserve the entry itself */
652 memblock_reserve(prsv,
653 struct_size(rsv, entry, rsv->size));
654
655 for (i = 0; i < atomic_read(&rsv->count); i++) {
656 memblock_reserve(rsv->entry[i].base,
657 rsv->entry[i].size);
658 }
659
660 prsv = rsv->next;
661 early_memunmap(p, PAGE_SIZE);
662 }
663 }
664
665 if (rt_prop != EFI_INVALID_TABLE_ADDR) {
666 efi_rt_properties_table_t *tbl;
667
668 tbl = early_memremap(rt_prop, sizeof(*tbl));
669 if (tbl) {
670 efi.runtime_supported_mask &= tbl->runtime_services_supported;
671 early_memunmap(tbl, sizeof(*tbl));
672 }
673 }
674
675 return 0;
676 }
677
efi_systab_check_header(const efi_table_hdr_t * systab_hdr,int min_major_version)678 int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr,
679 int min_major_version)
680 {
681 if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) {
682 pr_err("System table signature incorrect!\n");
683 return -EINVAL;
684 }
685
686 if ((systab_hdr->revision >> 16) < min_major_version)
687 pr_err("Warning: System table version %d.%02d, expected %d.00 or greater!\n",
688 systab_hdr->revision >> 16,
689 systab_hdr->revision & 0xffff,
690 min_major_version);
691
692 return 0;
693 }
694
695 #ifndef CONFIG_IA64
map_fw_vendor(unsigned long fw_vendor,size_t size)696 static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor,
697 size_t size)
698 {
699 const efi_char16_t *ret;
700
701 ret = early_memremap_ro(fw_vendor, size);
702 if (!ret)
703 pr_err("Could not map the firmware vendor!\n");
704 return ret;
705 }
706
unmap_fw_vendor(const void * fw_vendor,size_t size)707 static void __init unmap_fw_vendor(const void *fw_vendor, size_t size)
708 {
709 early_memunmap((void *)fw_vendor, size);
710 }
711 #else
712 #define map_fw_vendor(p, s) __va(p)
713 #define unmap_fw_vendor(v, s)
714 #endif
715
efi_systab_report_header(const efi_table_hdr_t * systab_hdr,unsigned long fw_vendor)716 void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
717 unsigned long fw_vendor)
718 {
719 char vendor[100] = "unknown";
720 const efi_char16_t *c16;
721 size_t i;
722
723 c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t));
724 if (c16) {
725 for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
726 vendor[i] = c16[i];
727 vendor[i] = '\0';
728
729 unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t));
730 }
731
732 pr_info("EFI v%u.%.02u by %s\n",
733 systab_hdr->revision >> 16,
734 systab_hdr->revision & 0xffff,
735 vendor);
736
737 if (IS_ENABLED(CONFIG_X86_64) &&
738 systab_hdr->revision > EFI_1_10_SYSTEM_TABLE_REVISION &&
739 !strcmp(vendor, "Apple")) {
740 pr_info("Apple Mac detected, using EFI v1.10 runtime services only\n");
741 efi.runtime_version = EFI_1_10_SYSTEM_TABLE_REVISION;
742 }
743 }
744
745 static __initdata char memory_type_name[][13] = {
746 "Reserved",
747 "Loader Code",
748 "Loader Data",
749 "Boot Code",
750 "Boot Data",
751 "Runtime Code",
752 "Runtime Data",
753 "Conventional",
754 "Unusable",
755 "ACPI Reclaim",
756 "ACPI Mem NVS",
757 "MMIO",
758 "MMIO Port",
759 "PAL Code",
760 "Persistent",
761 };
762
efi_md_typeattr_format(char * buf,size_t size,const efi_memory_desc_t * md)763 char * __init efi_md_typeattr_format(char *buf, size_t size,
764 const efi_memory_desc_t *md)
765 {
766 char *pos;
767 int type_len;
768 u64 attr;
769
770 pos = buf;
771 if (md->type >= ARRAY_SIZE(memory_type_name))
772 type_len = snprintf(pos, size, "[type=%u", md->type);
773 else
774 type_len = snprintf(pos, size, "[%-*s",
775 (int)(sizeof(memory_type_name[0]) - 1),
776 memory_type_name[md->type]);
777 if (type_len >= size)
778 return buf;
779
780 pos += type_len;
781 size -= type_len;
782
783 attr = md->attribute;
784 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
785 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
786 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
787 EFI_MEMORY_NV | EFI_MEMORY_SP | EFI_MEMORY_CPU_CRYPTO |
788 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
789 snprintf(pos, size, "|attr=0x%016llx]",
790 (unsigned long long)attr);
791 else
792 snprintf(pos, size,
793 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
794 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
795 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
796 attr & EFI_MEMORY_CPU_CRYPTO ? "CC" : "",
797 attr & EFI_MEMORY_SP ? "SP" : "",
798 attr & EFI_MEMORY_NV ? "NV" : "",
799 attr & EFI_MEMORY_XP ? "XP" : "",
800 attr & EFI_MEMORY_RP ? "RP" : "",
801 attr & EFI_MEMORY_WP ? "WP" : "",
802 attr & EFI_MEMORY_RO ? "RO" : "",
803 attr & EFI_MEMORY_UCE ? "UCE" : "",
804 attr & EFI_MEMORY_WB ? "WB" : "",
805 attr & EFI_MEMORY_WT ? "WT" : "",
806 attr & EFI_MEMORY_WC ? "WC" : "",
807 attr & EFI_MEMORY_UC ? "UC" : "");
808 return buf;
809 }
810
811 /*
812 * IA64 has a funky EFI memory map that doesn't work the same way as
813 * other architectures.
814 */
815 #ifndef CONFIG_IA64
816 /*
817 * efi_mem_attributes - lookup memmap attributes for physical address
818 * @phys_addr: the physical address to lookup
819 *
820 * Search in the EFI memory map for the region covering
821 * @phys_addr. Returns the EFI memory attributes if the region
822 * was found in the memory map, 0 otherwise.
823 */
efi_mem_attributes(unsigned long phys_addr)824 u64 efi_mem_attributes(unsigned long phys_addr)
825 {
826 efi_memory_desc_t *md;
827
828 if (!efi_enabled(EFI_MEMMAP))
829 return 0;
830
831 for_each_efi_memory_desc(md) {
832 if ((md->phys_addr <= phys_addr) &&
833 (phys_addr < (md->phys_addr +
834 (md->num_pages << EFI_PAGE_SHIFT))))
835 return md->attribute;
836 }
837 return 0;
838 }
839
840 /*
841 * efi_mem_type - lookup memmap type for physical address
842 * @phys_addr: the physical address to lookup
843 *
844 * Search in the EFI memory map for the region covering @phys_addr.
845 * Returns the EFI memory type if the region was found in the memory
846 * map, -EINVAL otherwise.
847 */
efi_mem_type(unsigned long phys_addr)848 int efi_mem_type(unsigned long phys_addr)
849 {
850 const efi_memory_desc_t *md;
851
852 if (!efi_enabled(EFI_MEMMAP))
853 return -ENOTSUPP;
854
855 for_each_efi_memory_desc(md) {
856 if ((md->phys_addr <= phys_addr) &&
857 (phys_addr < (md->phys_addr +
858 (md->num_pages << EFI_PAGE_SHIFT))))
859 return md->type;
860 }
861 return -EINVAL;
862 }
863 #endif
864
efi_status_to_err(efi_status_t status)865 int efi_status_to_err(efi_status_t status)
866 {
867 int err;
868
869 switch (status) {
870 case EFI_SUCCESS:
871 err = 0;
872 break;
873 case EFI_INVALID_PARAMETER:
874 err = -EINVAL;
875 break;
876 case EFI_OUT_OF_RESOURCES:
877 err = -ENOSPC;
878 break;
879 case EFI_DEVICE_ERROR:
880 err = -EIO;
881 break;
882 case EFI_WRITE_PROTECTED:
883 err = -EROFS;
884 break;
885 case EFI_SECURITY_VIOLATION:
886 err = -EACCES;
887 break;
888 case EFI_NOT_FOUND:
889 err = -ENOENT;
890 break;
891 case EFI_ABORTED:
892 err = -EINTR;
893 break;
894 default:
895 err = -EINVAL;
896 }
897
898 return err;
899 }
900
901 static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
902 static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
903
efi_memreserve_map_root(void)904 static int __init efi_memreserve_map_root(void)
905 {
906 if (mem_reserve == EFI_INVALID_TABLE_ADDR)
907 return -ENODEV;
908
909 efi_memreserve_root = memremap(mem_reserve,
910 sizeof(*efi_memreserve_root),
911 MEMREMAP_WB);
912 if (WARN_ON_ONCE(!efi_memreserve_root))
913 return -ENOMEM;
914 return 0;
915 }
916
efi_mem_reserve_iomem(phys_addr_t addr,u64 size)917 static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size)
918 {
919 struct resource *res, *parent;
920 int ret;
921
922 res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
923 if (!res)
924 return -ENOMEM;
925
926 res->name = "reserved";
927 res->flags = IORESOURCE_MEM;
928 res->start = addr;
929 res->end = addr + size - 1;
930
931 /* we expect a conflict with a 'System RAM' region */
932 parent = request_resource_conflict(&iomem_resource, res);
933 ret = parent ? request_resource(parent, res) : 0;
934
935 /*
936 * Given that efi_mem_reserve_iomem() can be called at any
937 * time, only call memblock_reserve() if the architecture
938 * keeps the infrastructure around.
939 */
940 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK) && !ret)
941 memblock_reserve(addr, size);
942
943 return ret;
944 }
945
efi_mem_reserve_persistent(phys_addr_t addr,u64 size)946 int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
947 {
948 struct linux_efi_memreserve *rsv;
949 unsigned long prsv;
950 int rc, index;
951
952 if (efi_memreserve_root == (void *)ULONG_MAX)
953 return -ENODEV;
954
955 if (!efi_memreserve_root) {
956 rc = efi_memreserve_map_root();
957 if (rc)
958 return rc;
959 }
960
961 /* first try to find a slot in an existing linked list entry */
962 for (prsv = efi_memreserve_root->next; prsv; ) {
963 rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
964 index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
965 if (index < rsv->size) {
966 rsv->entry[index].base = addr;
967 rsv->entry[index].size = size;
968
969 memunmap(rsv);
970 return efi_mem_reserve_iomem(addr, size);
971 }
972 prsv = rsv->next;
973 memunmap(rsv);
974 }
975
976 /* no slot found - allocate a new linked list entry */
977 rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
978 if (!rsv)
979 return -ENOMEM;
980
981 rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K);
982 if (rc) {
983 free_page((unsigned long)rsv);
984 return rc;
985 }
986
987 /*
988 * The memremap() call above assumes that a linux_efi_memreserve entry
989 * never crosses a page boundary, so let's ensure that this remains true
990 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
991 * using SZ_4K explicitly in the size calculation below.
992 */
993 rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
994 atomic_set(&rsv->count, 1);
995 rsv->entry[0].base = addr;
996 rsv->entry[0].size = size;
997
998 spin_lock(&efi_mem_reserve_persistent_lock);
999 rsv->next = efi_memreserve_root->next;
1000 efi_memreserve_root->next = __pa(rsv);
1001 spin_unlock(&efi_mem_reserve_persistent_lock);
1002
1003 return efi_mem_reserve_iomem(addr, size);
1004 }
1005
efi_memreserve_root_init(void)1006 static int __init efi_memreserve_root_init(void)
1007 {
1008 if (efi_memreserve_root)
1009 return 0;
1010 if (efi_memreserve_map_root())
1011 efi_memreserve_root = (void *)ULONG_MAX;
1012 return 0;
1013 }
1014 early_initcall(efi_memreserve_root_init);
1015
1016 #ifdef CONFIG_KEXEC
update_efi_random_seed(struct notifier_block * nb,unsigned long code,void * unused)1017 static int update_efi_random_seed(struct notifier_block *nb,
1018 unsigned long code, void *unused)
1019 {
1020 struct linux_efi_random_seed *seed;
1021 u32 size = 0;
1022
1023 if (!kexec_in_progress)
1024 return NOTIFY_DONE;
1025
1026 seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB);
1027 if (seed != NULL) {
1028 size = min(seed->size, EFI_RANDOM_SEED_SIZE);
1029 memunmap(seed);
1030 } else {
1031 pr_err("Could not map UEFI random seed!\n");
1032 }
1033 if (size > 0) {
1034 seed = memremap(efi_rng_seed, sizeof(*seed) + size,
1035 MEMREMAP_WB);
1036 if (seed != NULL) {
1037 seed->size = size;
1038 get_random_bytes(seed->bits, seed->size);
1039 memunmap(seed);
1040 } else {
1041 pr_err("Could not map UEFI random seed!\n");
1042 }
1043 }
1044 return NOTIFY_DONE;
1045 }
1046
1047 static struct notifier_block efi_random_seed_nb = {
1048 .notifier_call = update_efi_random_seed,
1049 };
1050
register_update_efi_random_seed(void)1051 static int __init register_update_efi_random_seed(void)
1052 {
1053 if (efi_rng_seed == EFI_INVALID_TABLE_ADDR)
1054 return 0;
1055 return register_reboot_notifier(&efi_random_seed_nb);
1056 }
1057 late_initcall(register_update_efi_random_seed);
1058 #endif
1059