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/initrd.h>
25 #include <linux/io.h>
26 #include <linux/kexec.h>
27 #include <linux/platform_device.h>
28 #include <linux/random.h>
29 #include <linux/reboot.h>
30 #include <linux/slab.h>
31 #include <linux/acpi.h>
32 #include <linux/ucs2_string.h>
33 #include <linux/memblock.h>
34 #include <linux/security.h>
35
36 #include <asm/early_ioremap.h>
37
38 struct efi __read_mostly efi = {
39 .runtime_supported_mask = EFI_RT_SUPPORTED_ALL,
40 .acpi = EFI_INVALID_TABLE_ADDR,
41 .acpi20 = EFI_INVALID_TABLE_ADDR,
42 .smbios = EFI_INVALID_TABLE_ADDR,
43 .smbios3 = EFI_INVALID_TABLE_ADDR,
44 .esrt = EFI_INVALID_TABLE_ADDR,
45 .tpm_log = EFI_INVALID_TABLE_ADDR,
46 .tpm_final_log = EFI_INVALID_TABLE_ADDR,
47 #ifdef CONFIG_LOAD_UEFI_KEYS
48 .mokvar_table = EFI_INVALID_TABLE_ADDR,
49 #endif
50 #ifdef CONFIG_EFI_COCO_SECRET
51 .coco_secret = EFI_INVALID_TABLE_ADDR,
52 #endif
53 #ifdef CONFIG_UNACCEPTED_MEMORY
54 .unaccepted = EFI_INVALID_TABLE_ADDR,
55 #endif
56 };
57 EXPORT_SYMBOL(efi);
58
59 unsigned long __ro_after_init efi_rng_seed = EFI_INVALID_TABLE_ADDR;
60 static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR;
61 static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR;
62 static unsigned long __initdata initrd = EFI_INVALID_TABLE_ADDR;
63
64 extern unsigned long screen_info_table;
65
66 struct mm_struct efi_mm = {
67 .mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, efi_mm.mmap_lock),
68 .mm_users = ATOMIC_INIT(2),
69 .mm_count = ATOMIC_INIT(1),
70 .write_protect_seq = SEQCNT_ZERO(efi_mm.write_protect_seq),
71 MMAP_LOCK_INITIALIZER(efi_mm)
72 .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
73 .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
74 .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0},
75 };
76
77 struct workqueue_struct *efi_rts_wq;
78
79 static bool disable_runtime = IS_ENABLED(CONFIG_EFI_DISABLE_RUNTIME);
setup_noefi(char * arg)80 static int __init setup_noefi(char *arg)
81 {
82 disable_runtime = true;
83 return 0;
84 }
85 early_param("noefi", setup_noefi);
86
efi_runtime_disabled(void)87 bool efi_runtime_disabled(void)
88 {
89 return disable_runtime;
90 }
91
__efi_soft_reserve_enabled(void)92 bool __pure __efi_soft_reserve_enabled(void)
93 {
94 return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE);
95 }
96
parse_efi_cmdline(char * str)97 static int __init parse_efi_cmdline(char *str)
98 {
99 if (!str) {
100 pr_warn("need at least one option\n");
101 return -EINVAL;
102 }
103
104 if (parse_option_str(str, "debug"))
105 set_bit(EFI_DBG, &efi.flags);
106
107 if (parse_option_str(str, "noruntime"))
108 disable_runtime = true;
109
110 if (parse_option_str(str, "runtime"))
111 disable_runtime = false;
112
113 if (parse_option_str(str, "nosoftreserve"))
114 set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags);
115
116 return 0;
117 }
118 early_param("efi", parse_efi_cmdline);
119
120 struct kobject *efi_kobj;
121
122 /*
123 * Let's not leave out systab information that snuck into
124 * the efivars driver
125 * Note, do not add more fields in systab sysfs file as it breaks sysfs
126 * one value per file rule!
127 */
systab_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)128 static ssize_t systab_show(struct kobject *kobj,
129 struct kobj_attribute *attr, char *buf)
130 {
131 char *str = buf;
132
133 if (!kobj || !buf)
134 return -EINVAL;
135
136 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
137 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
138 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
139 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
140 /*
141 * If both SMBIOS and SMBIOS3 entry points are implemented, the
142 * SMBIOS3 entry point shall be preferred, so we list it first to
143 * let applications stop parsing after the first match.
144 */
145 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
146 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
147 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
148 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
149
150 if (IS_ENABLED(CONFIG_IA64) || IS_ENABLED(CONFIG_X86))
151 str = efi_systab_show_arch(str);
152
153 return str - buf;
154 }
155
156 static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
157
fw_platform_size_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)158 static ssize_t fw_platform_size_show(struct kobject *kobj,
159 struct kobj_attribute *attr, char *buf)
160 {
161 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
162 }
163
164 extern __weak struct kobj_attribute efi_attr_fw_vendor;
165 extern __weak struct kobj_attribute efi_attr_runtime;
166 extern __weak struct kobj_attribute efi_attr_config_table;
167 static struct kobj_attribute efi_attr_fw_platform_size =
168 __ATTR_RO(fw_platform_size);
169
170 static struct attribute *efi_subsys_attrs[] = {
171 &efi_attr_systab.attr,
172 &efi_attr_fw_platform_size.attr,
173 &efi_attr_fw_vendor.attr,
174 &efi_attr_runtime.attr,
175 &efi_attr_config_table.attr,
176 NULL,
177 };
178
efi_attr_is_visible(struct kobject * kobj,struct attribute * attr,int n)179 umode_t __weak efi_attr_is_visible(struct kobject *kobj, struct attribute *attr,
180 int n)
181 {
182 return attr->mode;
183 }
184
185 static const struct attribute_group efi_subsys_attr_group = {
186 .attrs = efi_subsys_attrs,
187 .is_visible = efi_attr_is_visible,
188 };
189
190 static struct efivars generic_efivars;
191 static struct efivar_operations generic_ops;
192
generic_ops_supported(void)193 static bool generic_ops_supported(void)
194 {
195 unsigned long name_size;
196 efi_status_t status;
197 efi_char16_t name;
198 efi_guid_t guid;
199
200 name_size = sizeof(name);
201
202 status = efi.get_next_variable(&name_size, &name, &guid);
203 if (status == EFI_UNSUPPORTED)
204 return false;
205
206 return true;
207 }
208
generic_ops_register(void)209 static int generic_ops_register(void)
210 {
211 if (!generic_ops_supported())
212 return 0;
213
214 generic_ops.get_variable = efi.get_variable;
215 generic_ops.get_next_variable = efi.get_next_variable;
216 generic_ops.query_variable_store = efi_query_variable_store;
217 generic_ops.query_variable_info = efi.query_variable_info;
218
219 if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) {
220 generic_ops.set_variable = efi.set_variable;
221 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
222 }
223 return efivars_register(&generic_efivars, &generic_ops);
224 }
225
generic_ops_unregister(void)226 static void generic_ops_unregister(void)
227 {
228 if (!generic_ops.get_variable)
229 return;
230
231 efivars_unregister(&generic_efivars);
232 }
233
234 #ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS
235 #define EFIVAR_SSDT_NAME_MAX 16UL
236 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
efivar_ssdt_setup(char * str)237 static int __init efivar_ssdt_setup(char *str)
238 {
239 int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
240
241 if (ret)
242 return ret;
243
244 if (strlen(str) < sizeof(efivar_ssdt))
245 memcpy(efivar_ssdt, str, strlen(str));
246 else
247 pr_warn("efivar_ssdt: name too long: %s\n", str);
248 return 1;
249 }
250 __setup("efivar_ssdt=", efivar_ssdt_setup);
251
efivar_ssdt_load(void)252 static __init int efivar_ssdt_load(void)
253 {
254 unsigned long name_size = 256;
255 efi_char16_t *name = NULL;
256 efi_status_t status;
257 efi_guid_t guid;
258
259 if (!efivar_ssdt[0])
260 return 0;
261
262 name = kzalloc(name_size, GFP_KERNEL);
263 if (!name)
264 return -ENOMEM;
265
266 for (;;) {
267 char utf8_name[EFIVAR_SSDT_NAME_MAX];
268 unsigned long data_size = 0;
269 void *data;
270 int limit;
271
272 status = efi.get_next_variable(&name_size, name, &guid);
273 if (status == EFI_NOT_FOUND) {
274 break;
275 } else if (status == EFI_BUFFER_TOO_SMALL) {
276 efi_char16_t *name_tmp =
277 krealloc(name, name_size, GFP_KERNEL);
278 if (!name_tmp) {
279 kfree(name);
280 return -ENOMEM;
281 }
282 name = name_tmp;
283 continue;
284 }
285
286 limit = min(EFIVAR_SSDT_NAME_MAX, name_size);
287 ucs2_as_utf8(utf8_name, name, limit - 1);
288 if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
289 continue;
290
291 pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt, &guid);
292
293 status = efi.get_variable(name, &guid, NULL, &data_size, NULL);
294 if (status != EFI_BUFFER_TOO_SMALL || !data_size)
295 return -EIO;
296
297 data = kmalloc(data_size, GFP_KERNEL);
298 if (!data)
299 return -ENOMEM;
300
301 status = efi.get_variable(name, &guid, NULL, &data_size, data);
302 if (status == EFI_SUCCESS) {
303 acpi_status ret = acpi_load_table(data, NULL);
304 if (ret)
305 pr_err("failed to load table: %u\n", ret);
306 else
307 continue;
308 } else {
309 pr_err("failed to get var data: 0x%lx\n", status);
310 }
311 kfree(data);
312 }
313 return 0;
314 }
315 #else
efivar_ssdt_load(void)316 static inline int efivar_ssdt_load(void) { return 0; }
317 #endif
318
319 #ifdef CONFIG_DEBUG_FS
320
321 #define EFI_DEBUGFS_MAX_BLOBS 32
322
323 static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS];
324
efi_debugfs_init(void)325 static void __init efi_debugfs_init(void)
326 {
327 struct dentry *efi_debugfs;
328 efi_memory_desc_t *md;
329 char name[32];
330 int type_count[EFI_BOOT_SERVICES_DATA + 1] = {};
331 int i = 0;
332
333 efi_debugfs = debugfs_create_dir("efi", NULL);
334 if (IS_ERR_OR_NULL(efi_debugfs))
335 return;
336
337 for_each_efi_memory_desc(md) {
338 switch (md->type) {
339 case EFI_BOOT_SERVICES_CODE:
340 snprintf(name, sizeof(name), "boot_services_code%d",
341 type_count[md->type]++);
342 break;
343 case EFI_BOOT_SERVICES_DATA:
344 snprintf(name, sizeof(name), "boot_services_data%d",
345 type_count[md->type]++);
346 break;
347 default:
348 continue;
349 }
350
351 if (i >= EFI_DEBUGFS_MAX_BLOBS) {
352 pr_warn("More then %d EFI boot service segments, only showing first %d in debugfs\n",
353 EFI_DEBUGFS_MAX_BLOBS, EFI_DEBUGFS_MAX_BLOBS);
354 break;
355 }
356
357 debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT;
358 debugfs_blob[i].data = memremap(md->phys_addr,
359 debugfs_blob[i].size,
360 MEMREMAP_WB);
361 if (!debugfs_blob[i].data)
362 continue;
363
364 debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]);
365 i++;
366 }
367 }
368 #else
efi_debugfs_init(void)369 static inline void efi_debugfs_init(void) {}
370 #endif
371
372 /*
373 * We register the efi subsystem with the firmware subsystem and the
374 * efivars subsystem with the efi subsystem, if the system was booted with
375 * EFI.
376 */
efisubsys_init(void)377 static int __init efisubsys_init(void)
378 {
379 int error;
380
381 if (!efi_enabled(EFI_RUNTIME_SERVICES))
382 efi.runtime_supported_mask = 0;
383
384 if (!efi_enabled(EFI_BOOT))
385 return 0;
386
387 if (efi.runtime_supported_mask) {
388 /*
389 * Since we process only one efi_runtime_service() at a time, an
390 * ordered workqueue (which creates only one execution context)
391 * should suffice for all our needs.
392 */
393 efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
394 if (!efi_rts_wq) {
395 pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
396 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
397 efi.runtime_supported_mask = 0;
398 return 0;
399 }
400 }
401
402 if (efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES))
403 platform_device_register_simple("rtc-efi", 0, NULL, 0);
404
405 /* We register the efi directory at /sys/firmware/efi */
406 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
407 if (!efi_kobj) {
408 pr_err("efi: Firmware registration failed.\n");
409 error = -ENOMEM;
410 goto err_destroy_wq;
411 }
412
413 if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
414 EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) {
415 error = generic_ops_register();
416 if (error)
417 goto err_put;
418 efivar_ssdt_load();
419 platform_device_register_simple("efivars", 0, NULL, 0);
420 }
421
422 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
423 if (error) {
424 pr_err("efi: Sysfs attribute export failed with error %d.\n",
425 error);
426 goto err_unregister;
427 }
428
429 /* and the standard mountpoint for efivarfs */
430 error = sysfs_create_mount_point(efi_kobj, "efivars");
431 if (error) {
432 pr_err("efivars: Subsystem registration failed.\n");
433 goto err_remove_group;
434 }
435
436 if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
437 efi_debugfs_init();
438
439 #ifdef CONFIG_EFI_COCO_SECRET
440 if (efi.coco_secret != EFI_INVALID_TABLE_ADDR)
441 platform_device_register_simple("efi_secret", 0, NULL, 0);
442 #endif
443
444 return 0;
445
446 err_remove_group:
447 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
448 err_unregister:
449 if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
450 EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME))
451 generic_ops_unregister();
452 err_put:
453 kobject_put(efi_kobj);
454 efi_kobj = NULL;
455 err_destroy_wq:
456 if (efi_rts_wq)
457 destroy_workqueue(efi_rts_wq);
458
459 return error;
460 }
461
462 subsys_initcall(efisubsys_init);
463
efi_find_mirror(void)464 void __init efi_find_mirror(void)
465 {
466 efi_memory_desc_t *md;
467 u64 mirror_size = 0, total_size = 0;
468
469 if (!efi_enabled(EFI_MEMMAP))
470 return;
471
472 for_each_efi_memory_desc(md) {
473 unsigned long long start = md->phys_addr;
474 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
475
476 total_size += size;
477 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
478 memblock_mark_mirror(start, size);
479 mirror_size += size;
480 }
481 }
482 if (mirror_size)
483 pr_info("Memory: %lldM/%lldM mirrored memory\n",
484 mirror_size>>20, total_size>>20);
485 }
486
487 /*
488 * Find the efi memory descriptor for a given physical address. Given a
489 * physical address, determine if it exists within an EFI Memory Map entry,
490 * and if so, populate the supplied memory descriptor with the appropriate
491 * data.
492 */
__efi_mem_desc_lookup(u64 phys_addr,efi_memory_desc_t * out_md)493 int __efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
494 {
495 efi_memory_desc_t *md;
496
497 if (!efi_enabled(EFI_MEMMAP)) {
498 pr_err_once("EFI_MEMMAP is not enabled.\n");
499 return -EINVAL;
500 }
501
502 if (!out_md) {
503 pr_err_once("out_md is null.\n");
504 return -EINVAL;
505 }
506
507 for_each_efi_memory_desc(md) {
508 u64 size;
509 u64 end;
510
511 /* skip bogus entries (including empty ones) */
512 if ((md->phys_addr & (EFI_PAGE_SIZE - 1)) ||
513 (md->num_pages <= 0) ||
514 (md->num_pages > (U64_MAX - md->phys_addr) >> EFI_PAGE_SHIFT))
515 continue;
516
517 size = md->num_pages << EFI_PAGE_SHIFT;
518 end = md->phys_addr + size;
519 if (phys_addr >= md->phys_addr && phys_addr < end) {
520 memcpy(out_md, md, sizeof(*out_md));
521 return 0;
522 }
523 }
524 return -ENOENT;
525 }
526
527 extern int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
528 __weak __alias(__efi_mem_desc_lookup);
529
530 /*
531 * Calculate the highest address of an efi memory descriptor.
532 */
efi_mem_desc_end(efi_memory_desc_t * md)533 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
534 {
535 u64 size = md->num_pages << EFI_PAGE_SHIFT;
536 u64 end = md->phys_addr + size;
537 return end;
538 }
539
efi_arch_mem_reserve(phys_addr_t addr,u64 size)540 void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
541
542 /**
543 * efi_mem_reserve - Reserve an EFI memory region
544 * @addr: Physical address to reserve
545 * @size: Size of reservation
546 *
547 * Mark a region as reserved from general kernel allocation and
548 * prevent it being released by efi_free_boot_services().
549 *
550 * This function should be called drivers once they've parsed EFI
551 * configuration tables to figure out where their data lives, e.g.
552 * efi_esrt_init().
553 */
efi_mem_reserve(phys_addr_t addr,u64 size)554 void __init efi_mem_reserve(phys_addr_t addr, u64 size)
555 {
556 /* efi_mem_reserve() does not work under Xen */
557 if (WARN_ON_ONCE(efi_enabled(EFI_PARAVIRT)))
558 return;
559
560 if (!memblock_is_region_reserved(addr, size))
561 memblock_reserve(addr, size);
562
563 /*
564 * Some architectures (x86) reserve all boot services ranges
565 * until efi_free_boot_services() because of buggy firmware
566 * implementations. This means the above memblock_reserve() is
567 * superfluous on x86 and instead what it needs to do is
568 * ensure the @start, @size is not freed.
569 */
570 efi_arch_mem_reserve(addr, size);
571 }
572
573 static const efi_config_table_type_t common_tables[] __initconst = {
574 {ACPI_20_TABLE_GUID, &efi.acpi20, "ACPI 2.0" },
575 {ACPI_TABLE_GUID, &efi.acpi, "ACPI" },
576 {SMBIOS_TABLE_GUID, &efi.smbios, "SMBIOS" },
577 {SMBIOS3_TABLE_GUID, &efi.smbios3, "SMBIOS 3.0" },
578 {EFI_SYSTEM_RESOURCE_TABLE_GUID, &efi.esrt, "ESRT" },
579 {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, &efi_mem_attr_table, "MEMATTR" },
580 {LINUX_EFI_RANDOM_SEED_TABLE_GUID, &efi_rng_seed, "RNG" },
581 {LINUX_EFI_TPM_EVENT_LOG_GUID, &efi.tpm_log, "TPMEventLog" },
582 {LINUX_EFI_TPM_FINAL_LOG_GUID, &efi.tpm_final_log, "TPMFinalLog" },
583 {LINUX_EFI_MEMRESERVE_TABLE_GUID, &mem_reserve, "MEMRESERVE" },
584 {LINUX_EFI_INITRD_MEDIA_GUID, &initrd, "INITRD" },
585 {EFI_RT_PROPERTIES_TABLE_GUID, &rt_prop, "RTPROP" },
586 #ifdef CONFIG_EFI_RCI2_TABLE
587 {DELLEMC_EFI_RCI2_TABLE_GUID, &rci2_table_phys },
588 #endif
589 #ifdef CONFIG_LOAD_UEFI_KEYS
590 {LINUX_EFI_MOK_VARIABLE_TABLE_GUID, &efi.mokvar_table, "MOKvar" },
591 #endif
592 #ifdef CONFIG_EFI_COCO_SECRET
593 {LINUX_EFI_COCO_SECRET_AREA_GUID, &efi.coco_secret, "CocoSecret" },
594 #endif
595 #ifdef CONFIG_UNACCEPTED_MEMORY
596 {LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID, &efi.unaccepted, "Unaccepted" },
597 #endif
598 #ifdef CONFIG_EFI_GENERIC_STUB
599 {LINUX_EFI_SCREEN_INFO_TABLE_GUID, &screen_info_table },
600 #endif
601 {},
602 };
603
match_config_table(const efi_guid_t * guid,unsigned long table,const efi_config_table_type_t * table_types)604 static __init int match_config_table(const efi_guid_t *guid,
605 unsigned long table,
606 const efi_config_table_type_t *table_types)
607 {
608 int i;
609
610 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
611 if (efi_guidcmp(*guid, table_types[i].guid))
612 continue;
613
614 if (!efi_config_table_is_usable(guid, table)) {
615 if (table_types[i].name[0])
616 pr_cont("(%s=0x%lx unusable) ",
617 table_types[i].name, table);
618 return 1;
619 }
620
621 *(table_types[i].ptr) = table;
622 if (table_types[i].name[0])
623 pr_cont("%s=0x%lx ", table_types[i].name, table);
624 return 1;
625 }
626
627 return 0;
628 }
629
630 /**
631 * reserve_unaccepted - Map and reserve unaccepted configuration table
632 * @unaccepted: Pointer to unaccepted memory table
633 *
634 * memblock_add() makes sure that the table is mapped in direct mapping. During
635 * normal boot it happens automatically because the table is allocated from
636 * usable memory. But during crashkernel boot only memory specifically reserved
637 * for crash scenario is mapped. memblock_add() forces the table to be mapped
638 * in crashkernel case.
639 *
640 * Align the range to the nearest page borders. Ranges smaller than page size
641 * are not going to be mapped.
642 *
643 * memblock_reserve() makes sure that future allocations will not touch the
644 * table.
645 */
646
reserve_unaccepted(struct efi_unaccepted_memory * unaccepted)647 static __init void reserve_unaccepted(struct efi_unaccepted_memory *unaccepted)
648 {
649 phys_addr_t start, size;
650
651 start = PAGE_ALIGN_DOWN(efi.unaccepted);
652 size = PAGE_ALIGN(sizeof(*unaccepted) + unaccepted->size);
653
654 memblock_add(start, size);
655 memblock_reserve(start, size);
656 }
657
efi_config_parse_tables(const efi_config_table_t * config_tables,int count,const efi_config_table_type_t * arch_tables)658 int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
659 int count,
660 const efi_config_table_type_t *arch_tables)
661 {
662 const efi_config_table_64_t *tbl64 = (void *)config_tables;
663 const efi_config_table_32_t *tbl32 = (void *)config_tables;
664 const efi_guid_t *guid;
665 unsigned long table;
666 int i;
667
668 pr_info("");
669 for (i = 0; i < count; i++) {
670 if (!IS_ENABLED(CONFIG_X86)) {
671 guid = &config_tables[i].guid;
672 table = (unsigned long)config_tables[i].table;
673 } else if (efi_enabled(EFI_64BIT)) {
674 guid = &tbl64[i].guid;
675 table = tbl64[i].table;
676
677 if (IS_ENABLED(CONFIG_X86_32) &&
678 tbl64[i].table > U32_MAX) {
679 pr_cont("\n");
680 pr_err("Table located above 4GB, disabling EFI.\n");
681 return -EINVAL;
682 }
683 } else {
684 guid = &tbl32[i].guid;
685 table = tbl32[i].table;
686 }
687
688 if (!match_config_table(guid, table, common_tables) && arch_tables)
689 match_config_table(guid, table, arch_tables);
690 }
691 pr_cont("\n");
692 set_bit(EFI_CONFIG_TABLES, &efi.flags);
693
694 if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) {
695 struct linux_efi_random_seed *seed;
696 u32 size = 0;
697
698 seed = early_memremap(efi_rng_seed, sizeof(*seed));
699 if (seed != NULL) {
700 size = min_t(u32, seed->size, SZ_1K); // sanity check
701 early_memunmap(seed, sizeof(*seed));
702 } else {
703 pr_err("Could not map UEFI random seed!\n");
704 }
705 if (size > 0) {
706 seed = early_memremap(efi_rng_seed,
707 sizeof(*seed) + size);
708 if (seed != NULL) {
709 add_bootloader_randomness(seed->bits, size);
710 memzero_explicit(seed->bits, size);
711 early_memunmap(seed, sizeof(*seed) + size);
712 } else {
713 pr_err("Could not map UEFI random seed!\n");
714 }
715 }
716 }
717
718 if (!IS_ENABLED(CONFIG_X86_32) && efi_enabled(EFI_MEMMAP))
719 efi_memattr_init();
720
721 efi_tpm_eventlog_init();
722
723 if (mem_reserve != EFI_INVALID_TABLE_ADDR) {
724 unsigned long prsv = mem_reserve;
725
726 while (prsv) {
727 struct linux_efi_memreserve *rsv;
728 u8 *p;
729
730 /*
731 * Just map a full page: that is what we will get
732 * anyway, and it permits us to map the entire entry
733 * before knowing its size.
734 */
735 p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
736 PAGE_SIZE);
737 if (p == NULL) {
738 pr_err("Could not map UEFI memreserve entry!\n");
739 return -ENOMEM;
740 }
741
742 rsv = (void *)(p + prsv % PAGE_SIZE);
743
744 /* reserve the entry itself */
745 memblock_reserve(prsv,
746 struct_size(rsv, entry, rsv->size));
747
748 for (i = 0; i < atomic_read(&rsv->count); i++) {
749 memblock_reserve(rsv->entry[i].base,
750 rsv->entry[i].size);
751 }
752
753 prsv = rsv->next;
754 early_memunmap(p, PAGE_SIZE);
755 }
756 }
757
758 if (rt_prop != EFI_INVALID_TABLE_ADDR) {
759 efi_rt_properties_table_t *tbl;
760
761 tbl = early_memremap(rt_prop, sizeof(*tbl));
762 if (tbl) {
763 efi.runtime_supported_mask &= tbl->runtime_services_supported;
764 early_memunmap(tbl, sizeof(*tbl));
765 }
766 }
767
768 if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) &&
769 initrd != EFI_INVALID_TABLE_ADDR && phys_initrd_size == 0) {
770 struct linux_efi_initrd *tbl;
771
772 tbl = early_memremap(initrd, sizeof(*tbl));
773 if (tbl) {
774 phys_initrd_start = tbl->base;
775 phys_initrd_size = tbl->size;
776 early_memunmap(tbl, sizeof(*tbl));
777 }
778 }
779
780 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) &&
781 efi.unaccepted != EFI_INVALID_TABLE_ADDR) {
782 struct efi_unaccepted_memory *unaccepted;
783
784 unaccepted = early_memremap(efi.unaccepted, sizeof(*unaccepted));
785 if (unaccepted) {
786
787 if (unaccepted->version == 1) {
788 reserve_unaccepted(unaccepted);
789 } else {
790 efi.unaccepted = EFI_INVALID_TABLE_ADDR;
791 }
792
793 early_memunmap(unaccepted, sizeof(*unaccepted));
794 }
795 }
796
797 return 0;
798 }
799
efi_systab_check_header(const efi_table_hdr_t * systab_hdr)800 int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr)
801 {
802 if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) {
803 pr_err("System table signature incorrect!\n");
804 return -EINVAL;
805 }
806
807 return 0;
808 }
809
810 #ifndef CONFIG_IA64
map_fw_vendor(unsigned long fw_vendor,size_t size)811 static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor,
812 size_t size)
813 {
814 const efi_char16_t *ret;
815
816 ret = early_memremap_ro(fw_vendor, size);
817 if (!ret)
818 pr_err("Could not map the firmware vendor!\n");
819 return ret;
820 }
821
unmap_fw_vendor(const void * fw_vendor,size_t size)822 static void __init unmap_fw_vendor(const void *fw_vendor, size_t size)
823 {
824 early_memunmap((void *)fw_vendor, size);
825 }
826 #else
827 #define map_fw_vendor(p, s) __va(p)
828 #define unmap_fw_vendor(v, s)
829 #endif
830
efi_systab_report_header(const efi_table_hdr_t * systab_hdr,unsigned long fw_vendor)831 void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
832 unsigned long fw_vendor)
833 {
834 char vendor[100] = "unknown";
835 const efi_char16_t *c16;
836 size_t i;
837 u16 rev;
838
839 c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t));
840 if (c16) {
841 for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
842 vendor[i] = c16[i];
843 vendor[i] = '\0';
844
845 unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t));
846 }
847
848 rev = (u16)systab_hdr->revision;
849 pr_info("EFI v%u.%u", systab_hdr->revision >> 16, rev / 10);
850
851 rev %= 10;
852 if (rev)
853 pr_cont(".%u", rev);
854
855 pr_cont(" by %s\n", vendor);
856
857 if (IS_ENABLED(CONFIG_X86_64) &&
858 systab_hdr->revision > EFI_1_10_SYSTEM_TABLE_REVISION &&
859 !strcmp(vendor, "Apple")) {
860 pr_info("Apple Mac detected, using EFI v1.10 runtime services only\n");
861 efi.runtime_version = EFI_1_10_SYSTEM_TABLE_REVISION;
862 }
863 }
864
865 static __initdata char memory_type_name[][13] = {
866 "Reserved",
867 "Loader Code",
868 "Loader Data",
869 "Boot Code",
870 "Boot Data",
871 "Runtime Code",
872 "Runtime Data",
873 "Conventional",
874 "Unusable",
875 "ACPI Reclaim",
876 "ACPI Mem NVS",
877 "MMIO",
878 "MMIO Port",
879 "PAL Code",
880 "Persistent",
881 "Unaccepted",
882 };
883
efi_md_typeattr_format(char * buf,size_t size,const efi_memory_desc_t * md)884 char * __init efi_md_typeattr_format(char *buf, size_t size,
885 const efi_memory_desc_t *md)
886 {
887 char *pos;
888 int type_len;
889 u64 attr;
890
891 pos = buf;
892 if (md->type >= ARRAY_SIZE(memory_type_name))
893 type_len = snprintf(pos, size, "[type=%u", md->type);
894 else
895 type_len = snprintf(pos, size, "[%-*s",
896 (int)(sizeof(memory_type_name[0]) - 1),
897 memory_type_name[md->type]);
898 if (type_len >= size)
899 return buf;
900
901 pos += type_len;
902 size -= type_len;
903
904 attr = md->attribute;
905 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
906 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
907 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
908 EFI_MEMORY_NV | EFI_MEMORY_SP | EFI_MEMORY_CPU_CRYPTO |
909 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
910 snprintf(pos, size, "|attr=0x%016llx]",
911 (unsigned long long)attr);
912 else
913 snprintf(pos, size,
914 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
915 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
916 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
917 attr & EFI_MEMORY_CPU_CRYPTO ? "CC" : "",
918 attr & EFI_MEMORY_SP ? "SP" : "",
919 attr & EFI_MEMORY_NV ? "NV" : "",
920 attr & EFI_MEMORY_XP ? "XP" : "",
921 attr & EFI_MEMORY_RP ? "RP" : "",
922 attr & EFI_MEMORY_WP ? "WP" : "",
923 attr & EFI_MEMORY_RO ? "RO" : "",
924 attr & EFI_MEMORY_UCE ? "UCE" : "",
925 attr & EFI_MEMORY_WB ? "WB" : "",
926 attr & EFI_MEMORY_WT ? "WT" : "",
927 attr & EFI_MEMORY_WC ? "WC" : "",
928 attr & EFI_MEMORY_UC ? "UC" : "");
929 return buf;
930 }
931
932 /*
933 * IA64 has a funky EFI memory map that doesn't work the same way as
934 * other architectures.
935 */
936 #ifndef CONFIG_IA64
937 /*
938 * efi_mem_attributes - lookup memmap attributes for physical address
939 * @phys_addr: the physical address to lookup
940 *
941 * Search in the EFI memory map for the region covering
942 * @phys_addr. Returns the EFI memory attributes if the region
943 * was found in the memory map, 0 otherwise.
944 */
efi_mem_attributes(unsigned long phys_addr)945 u64 efi_mem_attributes(unsigned long phys_addr)
946 {
947 efi_memory_desc_t *md;
948
949 if (!efi_enabled(EFI_MEMMAP))
950 return 0;
951
952 for_each_efi_memory_desc(md) {
953 if ((md->phys_addr <= phys_addr) &&
954 (phys_addr < (md->phys_addr +
955 (md->num_pages << EFI_PAGE_SHIFT))))
956 return md->attribute;
957 }
958 return 0;
959 }
960
961 /*
962 * efi_mem_type - lookup memmap type for physical address
963 * @phys_addr: the physical address to lookup
964 *
965 * Search in the EFI memory map for the region covering @phys_addr.
966 * Returns the EFI memory type if the region was found in the memory
967 * map, -EINVAL otherwise.
968 */
efi_mem_type(unsigned long phys_addr)969 int efi_mem_type(unsigned long phys_addr)
970 {
971 const efi_memory_desc_t *md;
972
973 if (!efi_enabled(EFI_MEMMAP))
974 return -ENOTSUPP;
975
976 for_each_efi_memory_desc(md) {
977 if ((md->phys_addr <= phys_addr) &&
978 (phys_addr < (md->phys_addr +
979 (md->num_pages << EFI_PAGE_SHIFT))))
980 return md->type;
981 }
982 return -EINVAL;
983 }
984 #endif
985
efi_status_to_err(efi_status_t status)986 int efi_status_to_err(efi_status_t status)
987 {
988 int err;
989
990 switch (status) {
991 case EFI_SUCCESS:
992 err = 0;
993 break;
994 case EFI_INVALID_PARAMETER:
995 err = -EINVAL;
996 break;
997 case EFI_OUT_OF_RESOURCES:
998 err = -ENOSPC;
999 break;
1000 case EFI_DEVICE_ERROR:
1001 err = -EIO;
1002 break;
1003 case EFI_WRITE_PROTECTED:
1004 err = -EROFS;
1005 break;
1006 case EFI_SECURITY_VIOLATION:
1007 err = -EACCES;
1008 break;
1009 case EFI_NOT_FOUND:
1010 err = -ENOENT;
1011 break;
1012 case EFI_ABORTED:
1013 err = -EINTR;
1014 break;
1015 default:
1016 err = -EINVAL;
1017 }
1018
1019 return err;
1020 }
1021 EXPORT_SYMBOL_GPL(efi_status_to_err);
1022
1023 static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
1024 static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
1025
efi_memreserve_map_root(void)1026 static int __init efi_memreserve_map_root(void)
1027 {
1028 if (mem_reserve == EFI_INVALID_TABLE_ADDR)
1029 return -ENODEV;
1030
1031 efi_memreserve_root = memremap(mem_reserve,
1032 sizeof(*efi_memreserve_root),
1033 MEMREMAP_WB);
1034 if (WARN_ON_ONCE(!efi_memreserve_root))
1035 return -ENOMEM;
1036 return 0;
1037 }
1038
efi_mem_reserve_iomem(phys_addr_t addr,u64 size)1039 static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size)
1040 {
1041 struct resource *res, *parent;
1042 int ret;
1043
1044 res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
1045 if (!res)
1046 return -ENOMEM;
1047
1048 res->name = "reserved";
1049 res->flags = IORESOURCE_MEM;
1050 res->start = addr;
1051 res->end = addr + size - 1;
1052
1053 /* we expect a conflict with a 'System RAM' region */
1054 parent = request_resource_conflict(&iomem_resource, res);
1055 ret = parent ? request_resource(parent, res) : 0;
1056
1057 /*
1058 * Given that efi_mem_reserve_iomem() can be called at any
1059 * time, only call memblock_reserve() if the architecture
1060 * keeps the infrastructure around.
1061 */
1062 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK) && !ret)
1063 memblock_reserve(addr, size);
1064
1065 return ret;
1066 }
1067
efi_mem_reserve_persistent(phys_addr_t addr,u64 size)1068 int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
1069 {
1070 struct linux_efi_memreserve *rsv;
1071 unsigned long prsv;
1072 int rc, index;
1073
1074 if (efi_memreserve_root == (void *)ULONG_MAX)
1075 return -ENODEV;
1076
1077 if (!efi_memreserve_root) {
1078 rc = efi_memreserve_map_root();
1079 if (rc)
1080 return rc;
1081 }
1082
1083 /* first try to find a slot in an existing linked list entry */
1084 for (prsv = efi_memreserve_root->next; prsv; ) {
1085 rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
1086 if (!rsv)
1087 return -ENOMEM;
1088 index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
1089 if (index < rsv->size) {
1090 rsv->entry[index].base = addr;
1091 rsv->entry[index].size = size;
1092
1093 memunmap(rsv);
1094 return efi_mem_reserve_iomem(addr, size);
1095 }
1096 prsv = rsv->next;
1097 memunmap(rsv);
1098 }
1099
1100 /* no slot found - allocate a new linked list entry */
1101 rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
1102 if (!rsv)
1103 return -ENOMEM;
1104
1105 rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K);
1106 if (rc) {
1107 free_page((unsigned long)rsv);
1108 return rc;
1109 }
1110
1111 /*
1112 * The memremap() call above assumes that a linux_efi_memreserve entry
1113 * never crosses a page boundary, so let's ensure that this remains true
1114 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
1115 * using SZ_4K explicitly in the size calculation below.
1116 */
1117 rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
1118 atomic_set(&rsv->count, 1);
1119 rsv->entry[0].base = addr;
1120 rsv->entry[0].size = size;
1121
1122 spin_lock(&efi_mem_reserve_persistent_lock);
1123 rsv->next = efi_memreserve_root->next;
1124 efi_memreserve_root->next = __pa(rsv);
1125 spin_unlock(&efi_mem_reserve_persistent_lock);
1126
1127 return efi_mem_reserve_iomem(addr, size);
1128 }
1129
efi_memreserve_root_init(void)1130 static int __init efi_memreserve_root_init(void)
1131 {
1132 if (efi_memreserve_root)
1133 return 0;
1134 if (efi_memreserve_map_root())
1135 efi_memreserve_root = (void *)ULONG_MAX;
1136 return 0;
1137 }
1138 early_initcall(efi_memreserve_root_init);
1139
1140 #ifdef CONFIG_KEXEC
update_efi_random_seed(struct notifier_block * nb,unsigned long code,void * unused)1141 static int update_efi_random_seed(struct notifier_block *nb,
1142 unsigned long code, void *unused)
1143 {
1144 struct linux_efi_random_seed *seed;
1145 u32 size = 0;
1146
1147 if (!kexec_in_progress)
1148 return NOTIFY_DONE;
1149
1150 seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB);
1151 if (seed != NULL) {
1152 size = min(seed->size, EFI_RANDOM_SEED_SIZE);
1153 memunmap(seed);
1154 } else {
1155 pr_err("Could not map UEFI random seed!\n");
1156 }
1157 if (size > 0) {
1158 seed = memremap(efi_rng_seed, sizeof(*seed) + size,
1159 MEMREMAP_WB);
1160 if (seed != NULL) {
1161 seed->size = size;
1162 get_random_bytes(seed->bits, seed->size);
1163 memunmap(seed);
1164 } else {
1165 pr_err("Could not map UEFI random seed!\n");
1166 }
1167 }
1168 return NOTIFY_DONE;
1169 }
1170
1171 static struct notifier_block efi_random_seed_nb = {
1172 .notifier_call = update_efi_random_seed,
1173 };
1174
register_update_efi_random_seed(void)1175 static int __init register_update_efi_random_seed(void)
1176 {
1177 if (efi_rng_seed == EFI_INVALID_TABLE_ADDR)
1178 return 0;
1179 return register_reboot_notifier(&efi_random_seed_nb);
1180 }
1181 late_initcall(register_update_efi_random_seed);
1182 #endif
1183