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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
38struct 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};
54EXPORT_SYMBOL(efi);
55
56unsigned long __ro_after_init efi_rng_seed = EFI_INVALID_TABLE_ADDR;
57static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR;
58static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR;
59static unsigned long __initdata initrd = EFI_INVALID_TABLE_ADDR;
60
61extern unsigned long screen_info_table;
62
63struct mm_struct efi_mm = {
64 .mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, efi_mm.mmap_lock),
65 .mm_users = ATOMIC_INIT(2),
66 .mm_count = ATOMIC_INIT(1),
67 .write_protect_seq = SEQCNT_ZERO(efi_mm.write_protect_seq),
68 MMAP_LOCK_INITIALIZER(efi_mm)
69 .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
70 .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
71 .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0},
72};
73
74struct workqueue_struct *efi_rts_wq;
75
76static bool disable_runtime = IS_ENABLED(CONFIG_EFI_DISABLE_RUNTIME);
77static int __init setup_noefi(char *arg)
78{
79 disable_runtime = true;
80 return 0;
81}
82early_param("noefi", setup_noefi);
83
84bool efi_runtime_disabled(void)
85{
86 return disable_runtime;
87}
88
89bool __pure __efi_soft_reserve_enabled(void)
90{
91 return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE);
92}
93
94static int __init parse_efi_cmdline(char *str)
95{
96 if (!str) {
97 pr_warn("need at least one option\n");
98 return -EINVAL;
99 }
100
101 if (parse_option_str(str, "debug"))
102 set_bit(EFI_DBG, &efi.flags);
103
104 if (parse_option_str(str, "noruntime"))
105 disable_runtime = true;
106
107 if (parse_option_str(str, "runtime"))
108 disable_runtime = false;
109
110 if (parse_option_str(str, "nosoftreserve"))
111 set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags);
112
113 return 0;
114}
115early_param("efi", parse_efi_cmdline);
116
117struct kobject *efi_kobj;
118
119/*
120 * Let's not leave out systab information that snuck into
121 * the efivars driver
122 * Note, do not add more fields in systab sysfs file as it breaks sysfs
123 * one value per file rule!
124 */
125static ssize_t systab_show(struct kobject *kobj,
126 struct kobj_attribute *attr, char *buf)
127{
128 char *str = buf;
129
130 if (!kobj || !buf)
131 return -EINVAL;
132
133 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
134 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
135 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
136 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
137 /*
138 * If both SMBIOS and SMBIOS3 entry points are implemented, the
139 * SMBIOS3 entry point shall be preferred, so we list it first to
140 * let applications stop parsing after the first match.
141 */
142 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
143 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
144 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
145 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
146
147 if (IS_ENABLED(CONFIG_IA64) || IS_ENABLED(CONFIG_X86))
148 str = efi_systab_show_arch(str);
149
150 return str - buf;
151}
152
153static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
154
155static ssize_t fw_platform_size_show(struct kobject *kobj,
156 struct kobj_attribute *attr, char *buf)
157{
158 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
159}
160
161extern __weak struct kobj_attribute efi_attr_fw_vendor;
162extern __weak struct kobj_attribute efi_attr_runtime;
163extern __weak struct kobj_attribute efi_attr_config_table;
164static struct kobj_attribute efi_attr_fw_platform_size =
165 __ATTR_RO(fw_platform_size);
166
167static struct attribute *efi_subsys_attrs[] = {
168 &efi_attr_systab.attr,
169 &efi_attr_fw_platform_size.attr,
170 &efi_attr_fw_vendor.attr,
171 &efi_attr_runtime.attr,
172 &efi_attr_config_table.attr,
173 NULL,
174};
175
176umode_t __weak efi_attr_is_visible(struct kobject *kobj, struct attribute *attr,
177 int n)
178{
179 return attr->mode;
180}
181
182static const struct attribute_group efi_subsys_attr_group = {
183 .attrs = efi_subsys_attrs,
184 .is_visible = efi_attr_is_visible,
185};
186
187static struct efivars generic_efivars;
188static struct efivar_operations generic_ops;
189
190static int generic_ops_register(void)
191{
192 generic_ops.get_variable = efi.get_variable;
193 generic_ops.get_next_variable = efi.get_next_variable;
194 generic_ops.query_variable_store = efi_query_variable_store;
195
196 if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) {
197 generic_ops.set_variable = efi.set_variable;
198 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
199 }
200 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
201}
202
203static void generic_ops_unregister(void)
204{
205 efivars_unregister(&generic_efivars);
206}
207
208#ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS
209#define EFIVAR_SSDT_NAME_MAX 16UL
210static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
211static int __init efivar_ssdt_setup(char *str)
212{
213 int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
214
215 if (ret)
216 return ret;
217
218 if (strlen(str) < sizeof(efivar_ssdt))
219 memcpy(efivar_ssdt, str, strlen(str));
220 else
221 pr_warn("efivar_ssdt: name too long: %s\n", str);
222 return 1;
223}
224__setup("efivar_ssdt=", efivar_ssdt_setup);
225
226static __init int efivar_ssdt_load(void)
227{
228 unsigned long name_size = 256;
229 efi_char16_t *name = NULL;
230 efi_status_t status;
231 efi_guid_t guid;
232
233 if (!efivar_ssdt[0])
234 return 0;
235
236 name = kzalloc(name_size, GFP_KERNEL);
237 if (!name)
238 return -ENOMEM;
239
240 for (;;) {
241 char utf8_name[EFIVAR_SSDT_NAME_MAX];
242 unsigned long data_size = 0;
243 void *data;
244 int limit;
245
246 status = efi.get_next_variable(&name_size, name, &guid);
247 if (status == EFI_NOT_FOUND) {
248 break;
249 } else if (status == EFI_BUFFER_TOO_SMALL) {
250 name = krealloc(name, name_size, GFP_KERNEL);
251 if (!name)
252 return -ENOMEM;
253 continue;
254 }
255
256 limit = min(EFIVAR_SSDT_NAME_MAX, name_size);
257 ucs2_as_utf8(utf8_name, name, limit - 1);
258 if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
259 continue;
260
261 pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt, &guid);
262
263 status = efi.get_variable(name, &guid, NULL, &data_size, NULL);
264 if (status != EFI_BUFFER_TOO_SMALL || !data_size)
265 return -EIO;
266
267 data = kmalloc(data_size, GFP_KERNEL);
268 if (!data)
269 return -ENOMEM;
270
271 status = efi.get_variable(name, &guid, NULL, &data_size, data);
272 if (status == EFI_SUCCESS) {
273 acpi_status ret = acpi_load_table(data, NULL);
274 if (ret)
275 pr_err("failed to load table: %u\n", ret);
276 else
277 continue;
278 } else {
279 pr_err("failed to get var data: 0x%lx\n", status);
280 }
281 kfree(data);
282 }
283 return 0;
284}
285#else
286static inline int efivar_ssdt_load(void) { return 0; }
287#endif
288
289#ifdef CONFIG_DEBUG_FS
290
291#define EFI_DEBUGFS_MAX_BLOBS 32
292
293static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS];
294
295static void __init efi_debugfs_init(void)
296{
297 struct dentry *efi_debugfs;
298 efi_memory_desc_t *md;
299 char name[32];
300 int type_count[EFI_BOOT_SERVICES_DATA + 1] = {};
301 int i = 0;
302
303 efi_debugfs = debugfs_create_dir("efi", NULL);
304 if (IS_ERR_OR_NULL(efi_debugfs))
305 return;
306
307 for_each_efi_memory_desc(md) {
308 switch (md->type) {
309 case EFI_BOOT_SERVICES_CODE:
310 snprintf(name, sizeof(name), "boot_services_code%d",
311 type_count[md->type]++);
312 break;
313 case EFI_BOOT_SERVICES_DATA:
314 snprintf(name, sizeof(name), "boot_services_data%d",
315 type_count[md->type]++);
316 break;
317 default:
318 continue;
319 }
320
321 if (i >= EFI_DEBUGFS_MAX_BLOBS) {
322 pr_warn("More then %d EFI boot service segments, only showing first %d in debugfs\n",
323 EFI_DEBUGFS_MAX_BLOBS, EFI_DEBUGFS_MAX_BLOBS);
324 break;
325 }
326
327 debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT;
328 debugfs_blob[i].data = memremap(md->phys_addr,
329 debugfs_blob[i].size,
330 MEMREMAP_WB);
331 if (!debugfs_blob[i].data)
332 continue;
333
334 debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]);
335 i++;
336 }
337}
338#else
339static inline void efi_debugfs_init(void) {}
340#endif
341
342static void refresh_nv_rng_seed(struct work_struct *work)
343{
344 u8 seed[EFI_RANDOM_SEED_SIZE];
345
346 get_random_bytes(seed, sizeof(seed));
347 efi.set_variable(L"RandomSeed", &LINUX_EFI_RANDOM_SEED_TABLE_GUID,
348 EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS |
349 EFI_VARIABLE_RUNTIME_ACCESS, sizeof(seed), seed);
350 memzero_explicit(seed, sizeof(seed));
351}
352static int refresh_nv_rng_seed_notification(struct notifier_block *nb, unsigned long action, void *data)
353{
354 static DECLARE_WORK(work, refresh_nv_rng_seed);
355 schedule_work(&work);
356 return NOTIFY_DONE;
357}
358static struct notifier_block refresh_nv_rng_seed_nb = { .notifier_call = refresh_nv_rng_seed_notification };
359
360/*
361 * We register the efi subsystem with the firmware subsystem and the
362 * efivars subsystem with the efi subsystem, if the system was booted with
363 * EFI.
364 */
365static int __init efisubsys_init(void)
366{
367 int error;
368
369 if (!efi_enabled(EFI_RUNTIME_SERVICES))
370 efi.runtime_supported_mask = 0;
371
372 if (!efi_enabled(EFI_BOOT))
373 return 0;
374
375 if (efi.runtime_supported_mask) {
376 /*
377 * Since we process only one efi_runtime_service() at a time, an
378 * ordered workqueue (which creates only one execution context)
379 * should suffice for all our needs.
380 */
381 efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
382 if (!efi_rts_wq) {
383 pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
384 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
385 efi.runtime_supported_mask = 0;
386 return 0;
387 }
388 }
389
390 if (efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES))
391 platform_device_register_simple("rtc-efi", 0, NULL, 0);
392
393 /* We register the efi directory at /sys/firmware/efi */
394 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
395 if (!efi_kobj) {
396 pr_err("efi: Firmware registration failed.\n");
397 error = -ENOMEM;
398 goto err_destroy_wq;
399 }
400
401 if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
402 EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) {
403 error = generic_ops_register();
404 if (error)
405 goto err_put;
406 efivar_ssdt_load();
407 platform_device_register_simple("efivars", 0, NULL, 0);
408 }
409
410 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
411 if (error) {
412 pr_err("efi: Sysfs attribute export failed with error %d.\n",
413 error);
414 goto err_unregister;
415 }
416
417 /* and the standard mountpoint for efivarfs */
418 error = sysfs_create_mount_point(efi_kobj, "efivars");
419 if (error) {
420 pr_err("efivars: Subsystem registration failed.\n");
421 goto err_remove_group;
422 }
423
424 if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
425 efi_debugfs_init();
426
427#ifdef CONFIG_EFI_COCO_SECRET
428 if (efi.coco_secret != EFI_INVALID_TABLE_ADDR)
429 platform_device_register_simple("efi_secret", 0, NULL, 0);
430#endif
431
432 if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE))
433 execute_with_initialized_rng(&refresh_nv_rng_seed_nb);
434
435 return 0;
436
437err_remove_group:
438 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
439err_unregister:
440 if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
441 EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME))
442 generic_ops_unregister();
443err_put:
444 kobject_put(efi_kobj);
445 efi_kobj = NULL;
446err_destroy_wq:
447 if (efi_rts_wq)
448 destroy_workqueue(efi_rts_wq);
449
450 return error;
451}
452
453subsys_initcall(efisubsys_init);
454
455void __init efi_find_mirror(void)
456{
457 efi_memory_desc_t *md;
458 u64 mirror_size = 0, total_size = 0;
459
460 if (!efi_enabled(EFI_MEMMAP))
461 return;
462
463 for_each_efi_memory_desc(md) {
464 unsigned long long start = md->phys_addr;
465 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
466
467 total_size += size;
468 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
469 memblock_mark_mirror(start, size);
470 mirror_size += size;
471 }
472 }
473 if (mirror_size)
474 pr_info("Memory: %lldM/%lldM mirrored memory\n",
475 mirror_size>>20, total_size>>20);
476}
477
478/*
479 * Find the efi memory descriptor for a given physical address. Given a
480 * physical address, determine if it exists within an EFI Memory Map entry,
481 * and if so, populate the supplied memory descriptor with the appropriate
482 * data.
483 */
484int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
485{
486 efi_memory_desc_t *md;
487
488 if (!efi_enabled(EFI_MEMMAP)) {
489 pr_err_once("EFI_MEMMAP is not enabled.\n");
490 return -EINVAL;
491 }
492
493 if (!out_md) {
494 pr_err_once("out_md is null.\n");
495 return -EINVAL;
496 }
497
498 for_each_efi_memory_desc(md) {
499 u64 size;
500 u64 end;
501
502 size = md->num_pages << EFI_PAGE_SHIFT;
503 end = md->phys_addr + size;
504 if (phys_addr >= md->phys_addr && phys_addr < end) {
505 memcpy(out_md, md, sizeof(*out_md));
506 return 0;
507 }
508 }
509 return -ENOENT;
510}
511
512/*
513 * Calculate the highest address of an efi memory descriptor.
514 */
515u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
516{
517 u64 size = md->num_pages << EFI_PAGE_SHIFT;
518 u64 end = md->phys_addr + size;
519 return end;
520}
521
522void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
523
524/**
525 * efi_mem_reserve - Reserve an EFI memory region
526 * @addr: Physical address to reserve
527 * @size: Size of reservation
528 *
529 * Mark a region as reserved from general kernel allocation and
530 * prevent it being released by efi_free_boot_services().
531 *
532 * This function should be called drivers once they've parsed EFI
533 * configuration tables to figure out where their data lives, e.g.
534 * efi_esrt_init().
535 */
536void __init efi_mem_reserve(phys_addr_t addr, u64 size)
537{
538 if (!memblock_is_region_reserved(addr, size))
539 memblock_reserve(addr, size);
540
541 /*
542 * Some architectures (x86) reserve all boot services ranges
543 * until efi_free_boot_services() because of buggy firmware
544 * implementations. This means the above memblock_reserve() is
545 * superfluous on x86 and instead what it needs to do is
546 * ensure the @start, @size is not freed.
547 */
548 efi_arch_mem_reserve(addr, size);
549}
550
551static const efi_config_table_type_t common_tables[] __initconst = {
552 {ACPI_20_TABLE_GUID, &efi.acpi20, "ACPI 2.0" },
553 {ACPI_TABLE_GUID, &efi.acpi, "ACPI" },
554 {SMBIOS_TABLE_GUID, &efi.smbios, "SMBIOS" },
555 {SMBIOS3_TABLE_GUID, &efi.smbios3, "SMBIOS 3.0" },
556 {EFI_SYSTEM_RESOURCE_TABLE_GUID, &efi.esrt, "ESRT" },
557 {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, &efi_mem_attr_table, "MEMATTR" },
558 {LINUX_EFI_RANDOM_SEED_TABLE_GUID, &efi_rng_seed, "RNG" },
559 {LINUX_EFI_TPM_EVENT_LOG_GUID, &efi.tpm_log, "TPMEventLog" },
560 {LINUX_EFI_TPM_FINAL_LOG_GUID, &efi.tpm_final_log, "TPMFinalLog" },
561 {LINUX_EFI_MEMRESERVE_TABLE_GUID, &mem_reserve, "MEMRESERVE" },
562 {LINUX_EFI_INITRD_MEDIA_GUID, &initrd, "INITRD" },
563 {EFI_RT_PROPERTIES_TABLE_GUID, &rt_prop, "RTPROP" },
564#ifdef CONFIG_EFI_RCI2_TABLE
565 {DELLEMC_EFI_RCI2_TABLE_GUID, &rci2_table_phys },
566#endif
567#ifdef CONFIG_LOAD_UEFI_KEYS
568 {LINUX_EFI_MOK_VARIABLE_TABLE_GUID, &efi.mokvar_table, "MOKvar" },
569#endif
570#ifdef CONFIG_EFI_COCO_SECRET
571 {LINUX_EFI_COCO_SECRET_AREA_GUID, &efi.coco_secret, "CocoSecret" },
572#endif
573#ifdef CONFIG_EFI_GENERIC_STUB
574 {LINUX_EFI_SCREEN_INFO_TABLE_GUID, &screen_info_table },
575#endif
576 {},
577};
578
579static __init int match_config_table(const efi_guid_t *guid,
580 unsigned long table,
581 const efi_config_table_type_t *table_types)
582{
583 int i;
584
585 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
586 if (!efi_guidcmp(*guid, table_types[i].guid)) {
587 *(table_types[i].ptr) = table;
588 if (table_types[i].name[0])
589 pr_cont("%s=0x%lx ",
590 table_types[i].name, table);
591 return 1;
592 }
593 }
594
595 return 0;
596}
597
598int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
599 int count,
600 const efi_config_table_type_t *arch_tables)
601{
602 const efi_config_table_64_t *tbl64 = (void *)config_tables;
603 const efi_config_table_32_t *tbl32 = (void *)config_tables;
604 const efi_guid_t *guid;
605 unsigned long table;
606 int i;
607
608 pr_info("");
609 for (i = 0; i < count; i++) {
610 if (!IS_ENABLED(CONFIG_X86)) {
611 guid = &config_tables[i].guid;
612 table = (unsigned long)config_tables[i].table;
613 } else if (efi_enabled(EFI_64BIT)) {
614 guid = &tbl64[i].guid;
615 table = tbl64[i].table;
616
617 if (IS_ENABLED(CONFIG_X86_32) &&
618 tbl64[i].table > U32_MAX) {
619 pr_cont("\n");
620 pr_err("Table located above 4GB, disabling EFI.\n");
621 return -EINVAL;
622 }
623 } else {
624 guid = &tbl32[i].guid;
625 table = tbl32[i].table;
626 }
627
628 if (!match_config_table(guid, table, common_tables) && arch_tables)
629 match_config_table(guid, table, arch_tables);
630 }
631 pr_cont("\n");
632 set_bit(EFI_CONFIG_TABLES, &efi.flags);
633
634 if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) {
635 struct linux_efi_random_seed *seed;
636 u32 size = 0;
637
638 seed = early_memremap(efi_rng_seed, sizeof(*seed));
639 if (seed != NULL) {
640 size = min_t(u32, seed->size, SZ_1K); // sanity check
641 early_memunmap(seed, sizeof(*seed));
642 } else {
643 pr_err("Could not map UEFI random seed!\n");
644 }
645 if (size > 0) {
646 seed = early_memremap(efi_rng_seed,
647 sizeof(*seed) + size);
648 if (seed != NULL) {
649 add_bootloader_randomness(seed->bits, size);
650 memzero_explicit(seed->bits, size);
651 early_memunmap(seed, sizeof(*seed) + size);
652 } else {
653 pr_err("Could not map UEFI random seed!\n");
654 }
655 }
656 }
657
658 if (!IS_ENABLED(CONFIG_X86_32) && efi_enabled(EFI_MEMMAP))
659 efi_memattr_init();
660
661 efi_tpm_eventlog_init();
662
663 if (mem_reserve != EFI_INVALID_TABLE_ADDR) {
664 unsigned long prsv = mem_reserve;
665
666 while (prsv) {
667 struct linux_efi_memreserve *rsv;
668 u8 *p;
669
670 /*
671 * Just map a full page: that is what we will get
672 * anyway, and it permits us to map the entire entry
673 * before knowing its size.
674 */
675 p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
676 PAGE_SIZE);
677 if (p == NULL) {
678 pr_err("Could not map UEFI memreserve entry!\n");
679 return -ENOMEM;
680 }
681
682 rsv = (void *)(p + prsv % PAGE_SIZE);
683
684 /* reserve the entry itself */
685 memblock_reserve(prsv,
686 struct_size(rsv, entry, rsv->size));
687
688 for (i = 0; i < atomic_read(&rsv->count); i++) {
689 memblock_reserve(rsv->entry[i].base,
690 rsv->entry[i].size);
691 }
692
693 prsv = rsv->next;
694 early_memunmap(p, PAGE_SIZE);
695 }
696 }
697
698 if (rt_prop != EFI_INVALID_TABLE_ADDR) {
699 efi_rt_properties_table_t *tbl;
700
701 tbl = early_memremap(rt_prop, sizeof(*tbl));
702 if (tbl) {
703 efi.runtime_supported_mask &= tbl->runtime_services_supported;
704 early_memunmap(tbl, sizeof(*tbl));
705 }
706 }
707
708 if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) &&
709 initrd != EFI_INVALID_TABLE_ADDR && phys_initrd_size == 0) {
710 struct linux_efi_initrd *tbl;
711
712 tbl = early_memremap(initrd, sizeof(*tbl));
713 if (tbl) {
714 phys_initrd_start = tbl->base;
715 phys_initrd_size = tbl->size;
716 early_memunmap(tbl, sizeof(*tbl));
717 }
718 }
719
720 return 0;
721}
722
723int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr,
724 int min_major_version)
725{
726 if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) {
727 pr_err("System table signature incorrect!\n");
728 return -EINVAL;
729 }
730
731 if ((systab_hdr->revision >> 16) < min_major_version)
732 pr_err("Warning: System table version %d.%02d, expected %d.00 or greater!\n",
733 systab_hdr->revision >> 16,
734 systab_hdr->revision & 0xffff,
735 min_major_version);
736
737 return 0;
738}
739
740#ifndef CONFIG_IA64
741static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor,
742 size_t size)
743{
744 const efi_char16_t *ret;
745
746 ret = early_memremap_ro(fw_vendor, size);
747 if (!ret)
748 pr_err("Could not map the firmware vendor!\n");
749 return ret;
750}
751
752static void __init unmap_fw_vendor(const void *fw_vendor, size_t size)
753{
754 early_memunmap((void *)fw_vendor, size);
755}
756#else
757#define map_fw_vendor(p, s) __va(p)
758#define unmap_fw_vendor(v, s)
759#endif
760
761void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
762 unsigned long fw_vendor)
763{
764 char vendor[100] = "unknown";
765 const efi_char16_t *c16;
766 size_t i;
767
768 c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t));
769 if (c16) {
770 for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
771 vendor[i] = c16[i];
772 vendor[i] = '\0';
773
774 unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t));
775 }
776
777 pr_info("EFI v%u.%.02u by %s\n",
778 systab_hdr->revision >> 16,
779 systab_hdr->revision & 0xffff,
780 vendor);
781
782 if (IS_ENABLED(CONFIG_X86_64) &&
783 systab_hdr->revision > EFI_1_10_SYSTEM_TABLE_REVISION &&
784 !strcmp(vendor, "Apple")) {
785 pr_info("Apple Mac detected, using EFI v1.10 runtime services only\n");
786 efi.runtime_version = EFI_1_10_SYSTEM_TABLE_REVISION;
787 }
788}
789
790static __initdata char memory_type_name[][13] = {
791 "Reserved",
792 "Loader Code",
793 "Loader Data",
794 "Boot Code",
795 "Boot Data",
796 "Runtime Code",
797 "Runtime Data",
798 "Conventional",
799 "Unusable",
800 "ACPI Reclaim",
801 "ACPI Mem NVS",
802 "MMIO",
803 "MMIO Port",
804 "PAL Code",
805 "Persistent",
806};
807
808char * __init efi_md_typeattr_format(char *buf, size_t size,
809 const efi_memory_desc_t *md)
810{
811 char *pos;
812 int type_len;
813 u64 attr;
814
815 pos = buf;
816 if (md->type >= ARRAY_SIZE(memory_type_name))
817 type_len = snprintf(pos, size, "[type=%u", md->type);
818 else
819 type_len = snprintf(pos, size, "[%-*s",
820 (int)(sizeof(memory_type_name[0]) - 1),
821 memory_type_name[md->type]);
822 if (type_len >= size)
823 return buf;
824
825 pos += type_len;
826 size -= type_len;
827
828 attr = md->attribute;
829 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
830 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
831 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
832 EFI_MEMORY_NV | EFI_MEMORY_SP | EFI_MEMORY_CPU_CRYPTO |
833 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
834 snprintf(pos, size, "|attr=0x%016llx]",
835 (unsigned long long)attr);
836 else
837 snprintf(pos, size,
838 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
839 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
840 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
841 attr & EFI_MEMORY_CPU_CRYPTO ? "CC" : "",
842 attr & EFI_MEMORY_SP ? "SP" : "",
843 attr & EFI_MEMORY_NV ? "NV" : "",
844 attr & EFI_MEMORY_XP ? "XP" : "",
845 attr & EFI_MEMORY_RP ? "RP" : "",
846 attr & EFI_MEMORY_WP ? "WP" : "",
847 attr & EFI_MEMORY_RO ? "RO" : "",
848 attr & EFI_MEMORY_UCE ? "UCE" : "",
849 attr & EFI_MEMORY_WB ? "WB" : "",
850 attr & EFI_MEMORY_WT ? "WT" : "",
851 attr & EFI_MEMORY_WC ? "WC" : "",
852 attr & EFI_MEMORY_UC ? "UC" : "");
853 return buf;
854}
855
856/*
857 * IA64 has a funky EFI memory map that doesn't work the same way as
858 * other architectures.
859 */
860#ifndef CONFIG_IA64
861/*
862 * efi_mem_attributes - lookup memmap attributes for physical address
863 * @phys_addr: the physical address to lookup
864 *
865 * Search in the EFI memory map for the region covering
866 * @phys_addr. Returns the EFI memory attributes if the region
867 * was found in the memory map, 0 otherwise.
868 */
869u64 efi_mem_attributes(unsigned long phys_addr)
870{
871 efi_memory_desc_t *md;
872
873 if (!efi_enabled(EFI_MEMMAP))
874 return 0;
875
876 for_each_efi_memory_desc(md) {
877 if ((md->phys_addr <= phys_addr) &&
878 (phys_addr < (md->phys_addr +
879 (md->num_pages << EFI_PAGE_SHIFT))))
880 return md->attribute;
881 }
882 return 0;
883}
884
885/*
886 * efi_mem_type - lookup memmap type for physical address
887 * @phys_addr: the physical address to lookup
888 *
889 * Search in the EFI memory map for the region covering @phys_addr.
890 * Returns the EFI memory type if the region was found in the memory
891 * map, -EINVAL otherwise.
892 */
893int efi_mem_type(unsigned long phys_addr)
894{
895 const efi_memory_desc_t *md;
896
897 if (!efi_enabled(EFI_MEMMAP))
898 return -ENOTSUPP;
899
900 for_each_efi_memory_desc(md) {
901 if ((md->phys_addr <= phys_addr) &&
902 (phys_addr < (md->phys_addr +
903 (md->num_pages << EFI_PAGE_SHIFT))))
904 return md->type;
905 }
906 return -EINVAL;
907}
908#endif
909
910int efi_status_to_err(efi_status_t status)
911{
912 int err;
913
914 switch (status) {
915 case EFI_SUCCESS:
916 err = 0;
917 break;
918 case EFI_INVALID_PARAMETER:
919 err = -EINVAL;
920 break;
921 case EFI_OUT_OF_RESOURCES:
922 err = -ENOSPC;
923 break;
924 case EFI_DEVICE_ERROR:
925 err = -EIO;
926 break;
927 case EFI_WRITE_PROTECTED:
928 err = -EROFS;
929 break;
930 case EFI_SECURITY_VIOLATION:
931 err = -EACCES;
932 break;
933 case EFI_NOT_FOUND:
934 err = -ENOENT;
935 break;
936 case EFI_ABORTED:
937 err = -EINTR;
938 break;
939 default:
940 err = -EINVAL;
941 }
942
943 return err;
944}
945EXPORT_SYMBOL_GPL(efi_status_to_err);
946
947static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
948static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
949
950static int __init efi_memreserve_map_root(void)
951{
952 if (mem_reserve == EFI_INVALID_TABLE_ADDR)
953 return -ENODEV;
954
955 efi_memreserve_root = memremap(mem_reserve,
956 sizeof(*efi_memreserve_root),
957 MEMREMAP_WB);
958 if (WARN_ON_ONCE(!efi_memreserve_root))
959 return -ENOMEM;
960 return 0;
961}
962
963static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size)
964{
965 struct resource *res, *parent;
966 int ret;
967
968 res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
969 if (!res)
970 return -ENOMEM;
971
972 res->name = "reserved";
973 res->flags = IORESOURCE_MEM;
974 res->start = addr;
975 res->end = addr + size - 1;
976
977 /* we expect a conflict with a 'System RAM' region */
978 parent = request_resource_conflict(&iomem_resource, res);
979 ret = parent ? request_resource(parent, res) : 0;
980
981 /*
982 * Given that efi_mem_reserve_iomem() can be called at any
983 * time, only call memblock_reserve() if the architecture
984 * keeps the infrastructure around.
985 */
986 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK) && !ret)
987 memblock_reserve(addr, size);
988
989 return ret;
990}
991
992int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
993{
994 struct linux_efi_memreserve *rsv;
995 unsigned long prsv;
996 int rc, index;
997
998 if (efi_memreserve_root == (void *)ULONG_MAX)
999 return -ENODEV;
1000
1001 if (!efi_memreserve_root) {
1002 rc = efi_memreserve_map_root();
1003 if (rc)
1004 return rc;
1005 }
1006
1007 /* first try to find a slot in an existing linked list entry */
1008 for (prsv = efi_memreserve_root->next; prsv; ) {
1009 rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
1010 if (!rsv)
1011 return -ENOMEM;
1012 index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
1013 if (index < rsv->size) {
1014 rsv->entry[index].base = addr;
1015 rsv->entry[index].size = size;
1016
1017 memunmap(rsv);
1018 return efi_mem_reserve_iomem(addr, size);
1019 }
1020 prsv = rsv->next;
1021 memunmap(rsv);
1022 }
1023
1024 /* no slot found - allocate a new linked list entry */
1025 rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
1026 if (!rsv)
1027 return -ENOMEM;
1028
1029 rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K);
1030 if (rc) {
1031 free_page((unsigned long)rsv);
1032 return rc;
1033 }
1034
1035 /*
1036 * The memremap() call above assumes that a linux_efi_memreserve entry
1037 * never crosses a page boundary, so let's ensure that this remains true
1038 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
1039 * using SZ_4K explicitly in the size calculation below.
1040 */
1041 rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
1042 atomic_set(&rsv->count, 1);
1043 rsv->entry[0].base = addr;
1044 rsv->entry[0].size = size;
1045
1046 spin_lock(&efi_mem_reserve_persistent_lock);
1047 rsv->next = efi_memreserve_root->next;
1048 efi_memreserve_root->next = __pa(rsv);
1049 spin_unlock(&efi_mem_reserve_persistent_lock);
1050
1051 return efi_mem_reserve_iomem(addr, size);
1052}
1053
1054static int __init efi_memreserve_root_init(void)
1055{
1056 if (efi_memreserve_root)
1057 return 0;
1058 if (efi_memreserve_map_root())
1059 efi_memreserve_root = (void *)ULONG_MAX;
1060 return 0;
1061}
1062early_initcall(efi_memreserve_root_init);
1063
1064#ifdef CONFIG_KEXEC
1065static int update_efi_random_seed(struct notifier_block *nb,
1066 unsigned long code, void *unused)
1067{
1068 struct linux_efi_random_seed *seed;
1069 u32 size = 0;
1070
1071 if (!kexec_in_progress)
1072 return NOTIFY_DONE;
1073
1074 seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB);
1075 if (seed != NULL) {
1076 size = min(seed->size, EFI_RANDOM_SEED_SIZE);
1077 memunmap(seed);
1078 } else {
1079 pr_err("Could not map UEFI random seed!\n");
1080 }
1081 if (size > 0) {
1082 seed = memremap(efi_rng_seed, sizeof(*seed) + size,
1083 MEMREMAP_WB);
1084 if (seed != NULL) {
1085 seed->size = size;
1086 get_random_bytes(seed->bits, seed->size);
1087 memunmap(seed);
1088 } else {
1089 pr_err("Could not map UEFI random seed!\n");
1090 }
1091 }
1092 return NOTIFY_DONE;
1093}
1094
1095static struct notifier_block efi_random_seed_nb = {
1096 .notifier_call = update_efi_random_seed,
1097};
1098
1099static int __init register_update_efi_random_seed(void)
1100{
1101 if (efi_rng_seed == EFI_INVALID_TABLE_ADDR)
1102 return 0;
1103 return register_reboot_notifier(&efi_random_seed_nb);
1104}
1105late_initcall(register_update_efi_random_seed);
1106#endif
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/device.h>
21#include <linux/efi.h>
22#include <linux/of.h>
23#include <linux/of_fdt.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
37struct efi __read_mostly efi = {
38 .mps = EFI_INVALID_TABLE_ADDR,
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 .boot_info = EFI_INVALID_TABLE_ADDR,
44 .hcdp = EFI_INVALID_TABLE_ADDR,
45 .uga = EFI_INVALID_TABLE_ADDR,
46 .fw_vendor = EFI_INVALID_TABLE_ADDR,
47 .runtime = EFI_INVALID_TABLE_ADDR,
48 .config_table = EFI_INVALID_TABLE_ADDR,
49 .esrt = EFI_INVALID_TABLE_ADDR,
50 .properties_table = EFI_INVALID_TABLE_ADDR,
51 .mem_attr_table = EFI_INVALID_TABLE_ADDR,
52 .rng_seed = EFI_INVALID_TABLE_ADDR,
53 .tpm_log = EFI_INVALID_TABLE_ADDR,
54 .tpm_final_log = EFI_INVALID_TABLE_ADDR,
55 .mem_reserve = EFI_INVALID_TABLE_ADDR,
56};
57EXPORT_SYMBOL(efi);
58
59struct mm_struct efi_mm = {
60 .mm_rb = RB_ROOT,
61 .mm_users = ATOMIC_INIT(2),
62 .mm_count = ATOMIC_INIT(1),
63 .mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
64 .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
65 .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
66 .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0},
67};
68
69struct workqueue_struct *efi_rts_wq;
70
71static bool disable_runtime;
72static int __init setup_noefi(char *arg)
73{
74 disable_runtime = true;
75 return 0;
76}
77early_param("noefi", setup_noefi);
78
79bool efi_runtime_disabled(void)
80{
81 return disable_runtime;
82}
83
84static int __init parse_efi_cmdline(char *str)
85{
86 if (!str) {
87 pr_warn("need at least one option\n");
88 return -EINVAL;
89 }
90
91 if (parse_option_str(str, "debug"))
92 set_bit(EFI_DBG, &efi.flags);
93
94 if (parse_option_str(str, "noruntime"))
95 disable_runtime = true;
96
97 return 0;
98}
99early_param("efi", parse_efi_cmdline);
100
101struct kobject *efi_kobj;
102
103/*
104 * Let's not leave out systab information that snuck into
105 * the efivars driver
106 * Note, do not add more fields in systab sysfs file as it breaks sysfs
107 * one value per file rule!
108 */
109static ssize_t systab_show(struct kobject *kobj,
110 struct kobj_attribute *attr, char *buf)
111{
112 char *str = buf;
113
114 if (!kobj || !buf)
115 return -EINVAL;
116
117 if (efi.mps != EFI_INVALID_TABLE_ADDR)
118 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
119 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
120 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
121 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
122 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
123 /*
124 * If both SMBIOS and SMBIOS3 entry points are implemented, the
125 * SMBIOS3 entry point shall be preferred, so we list it first to
126 * let applications stop parsing after the first match.
127 */
128 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
129 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
130 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
131 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
132 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
133 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
134 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
135 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
136 if (efi.uga != EFI_INVALID_TABLE_ADDR)
137 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
138
139 return str - buf;
140}
141
142static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
143
144#define EFI_FIELD(var) efi.var
145
146#define EFI_ATTR_SHOW(name) \
147static ssize_t name##_show(struct kobject *kobj, \
148 struct kobj_attribute *attr, char *buf) \
149{ \
150 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
151}
152
153EFI_ATTR_SHOW(fw_vendor);
154EFI_ATTR_SHOW(runtime);
155EFI_ATTR_SHOW(config_table);
156
157static ssize_t fw_platform_size_show(struct kobject *kobj,
158 struct kobj_attribute *attr, char *buf)
159{
160 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
161}
162
163static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
164static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
165static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
166static struct kobj_attribute efi_attr_fw_platform_size =
167 __ATTR_RO(fw_platform_size);
168
169static struct attribute *efi_subsys_attrs[] = {
170 &efi_attr_systab.attr,
171 &efi_attr_fw_vendor.attr,
172 &efi_attr_runtime.attr,
173 &efi_attr_config_table.attr,
174 &efi_attr_fw_platform_size.attr,
175 NULL,
176};
177
178static umode_t efi_attr_is_visible(struct kobject *kobj,
179 struct attribute *attr, int n)
180{
181 if (attr == &efi_attr_fw_vendor.attr) {
182 if (efi_enabled(EFI_PARAVIRT) ||
183 efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
184 return 0;
185 } else if (attr == &efi_attr_runtime.attr) {
186 if (efi.runtime == EFI_INVALID_TABLE_ADDR)
187 return 0;
188 } else if (attr == &efi_attr_config_table.attr) {
189 if (efi.config_table == EFI_INVALID_TABLE_ADDR)
190 return 0;
191 }
192
193 return attr->mode;
194}
195
196static const struct attribute_group efi_subsys_attr_group = {
197 .attrs = efi_subsys_attrs,
198 .is_visible = efi_attr_is_visible,
199};
200
201static struct efivars generic_efivars;
202static struct efivar_operations generic_ops;
203
204static int generic_ops_register(void)
205{
206 generic_ops.get_variable = efi.get_variable;
207 generic_ops.set_variable = efi.set_variable;
208 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
209 generic_ops.get_next_variable = efi.get_next_variable;
210 generic_ops.query_variable_store = efi_query_variable_store;
211
212 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
213}
214
215static void generic_ops_unregister(void)
216{
217 efivars_unregister(&generic_efivars);
218}
219
220#if IS_ENABLED(CONFIG_ACPI)
221#define EFIVAR_SSDT_NAME_MAX 16
222static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
223static int __init efivar_ssdt_setup(char *str)
224{
225 int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
226
227 if (ret)
228 return ret;
229
230 if (strlen(str) < sizeof(efivar_ssdt))
231 memcpy(efivar_ssdt, str, strlen(str));
232 else
233 pr_warn("efivar_ssdt: name too long: %s\n", str);
234 return 0;
235}
236__setup("efivar_ssdt=", efivar_ssdt_setup);
237
238static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
239 unsigned long name_size, void *data)
240{
241 struct efivar_entry *entry;
242 struct list_head *list = data;
243 char utf8_name[EFIVAR_SSDT_NAME_MAX];
244 int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
245
246 ucs2_as_utf8(utf8_name, name, limit - 1);
247 if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
248 return 0;
249
250 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
251 if (!entry)
252 return 0;
253
254 memcpy(entry->var.VariableName, name, name_size);
255 memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
256
257 efivar_entry_add(entry, list);
258
259 return 0;
260}
261
262static __init int efivar_ssdt_load(void)
263{
264 LIST_HEAD(entries);
265 struct efivar_entry *entry, *aux;
266 unsigned long size;
267 void *data;
268 int ret;
269
270 if (!efivar_ssdt[0])
271 return 0;
272
273 ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
274
275 list_for_each_entry_safe(entry, aux, &entries, list) {
276 pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
277 &entry->var.VendorGuid);
278
279 list_del(&entry->list);
280
281 ret = efivar_entry_size(entry, &size);
282 if (ret) {
283 pr_err("failed to get var size\n");
284 goto free_entry;
285 }
286
287 data = kmalloc(size, GFP_KERNEL);
288 if (!data) {
289 ret = -ENOMEM;
290 goto free_entry;
291 }
292
293 ret = efivar_entry_get(entry, NULL, &size, data);
294 if (ret) {
295 pr_err("failed to get var data\n");
296 goto free_data;
297 }
298
299 ret = acpi_load_table(data);
300 if (ret) {
301 pr_err("failed to load table: %d\n", ret);
302 goto free_data;
303 }
304
305 goto free_entry;
306
307free_data:
308 kfree(data);
309
310free_entry:
311 kfree(entry);
312 }
313
314 return ret;
315}
316#else
317static inline int efivar_ssdt_load(void) { return 0; }
318#endif
319
320/*
321 * We register the efi subsystem with the firmware subsystem and the
322 * efivars subsystem with the efi subsystem, if the system was booted with
323 * EFI.
324 */
325static int __init efisubsys_init(void)
326{
327 int error;
328
329 if (!efi_enabled(EFI_BOOT))
330 return 0;
331
332 /*
333 * Since we process only one efi_runtime_service() at a time, an
334 * ordered workqueue (which creates only one execution context)
335 * should suffice all our needs.
336 */
337 efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
338 if (!efi_rts_wq) {
339 pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
340 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
341 return 0;
342 }
343
344 /* We register the efi directory at /sys/firmware/efi */
345 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
346 if (!efi_kobj) {
347 pr_err("efi: Firmware registration failed.\n");
348 return -ENOMEM;
349 }
350
351 error = generic_ops_register();
352 if (error)
353 goto err_put;
354
355 if (efi_enabled(EFI_RUNTIME_SERVICES))
356 efivar_ssdt_load();
357
358 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
359 if (error) {
360 pr_err("efi: Sysfs attribute export failed with error %d.\n",
361 error);
362 goto err_unregister;
363 }
364
365 error = efi_runtime_map_init(efi_kobj);
366 if (error)
367 goto err_remove_group;
368
369 /* and the standard mountpoint for efivarfs */
370 error = sysfs_create_mount_point(efi_kobj, "efivars");
371 if (error) {
372 pr_err("efivars: Subsystem registration failed.\n");
373 goto err_remove_group;
374 }
375
376 return 0;
377
378err_remove_group:
379 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
380err_unregister:
381 generic_ops_unregister();
382err_put:
383 kobject_put(efi_kobj);
384 return error;
385}
386
387subsys_initcall(efisubsys_init);
388
389/*
390 * Find the efi memory descriptor for a given physical address. Given a
391 * physical address, determine if it exists within an EFI Memory Map entry,
392 * and if so, populate the supplied memory descriptor with the appropriate
393 * data.
394 */
395int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
396{
397 efi_memory_desc_t *md;
398
399 if (!efi_enabled(EFI_MEMMAP)) {
400 pr_err_once("EFI_MEMMAP is not enabled.\n");
401 return -EINVAL;
402 }
403
404 if (!out_md) {
405 pr_err_once("out_md is null.\n");
406 return -EINVAL;
407 }
408
409 for_each_efi_memory_desc(md) {
410 u64 size;
411 u64 end;
412
413 size = md->num_pages << EFI_PAGE_SHIFT;
414 end = md->phys_addr + size;
415 if (phys_addr >= md->phys_addr && phys_addr < end) {
416 memcpy(out_md, md, sizeof(*out_md));
417 return 0;
418 }
419 }
420 return -ENOENT;
421}
422
423/*
424 * Calculate the highest address of an efi memory descriptor.
425 */
426u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
427{
428 u64 size = md->num_pages << EFI_PAGE_SHIFT;
429 u64 end = md->phys_addr + size;
430 return end;
431}
432
433void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
434
435/**
436 * efi_mem_reserve - Reserve an EFI memory region
437 * @addr: Physical address to reserve
438 * @size: Size of reservation
439 *
440 * Mark a region as reserved from general kernel allocation and
441 * prevent it being released by efi_free_boot_services().
442 *
443 * This function should be called drivers once they've parsed EFI
444 * configuration tables to figure out where their data lives, e.g.
445 * efi_esrt_init().
446 */
447void __init efi_mem_reserve(phys_addr_t addr, u64 size)
448{
449 if (!memblock_is_region_reserved(addr, size))
450 memblock_reserve(addr, size);
451
452 /*
453 * Some architectures (x86) reserve all boot services ranges
454 * until efi_free_boot_services() because of buggy firmware
455 * implementations. This means the above memblock_reserve() is
456 * superfluous on x86 and instead what it needs to do is
457 * ensure the @start, @size is not freed.
458 */
459 efi_arch_mem_reserve(addr, size);
460}
461
462static __initdata efi_config_table_type_t common_tables[] = {
463 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
464 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
465 {HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
466 {MPS_TABLE_GUID, "MPS", &efi.mps},
467 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
468 {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
469 {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
470 {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
471 {EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table},
472 {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table},
473 {LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi.rng_seed},
474 {LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log},
475 {LINUX_EFI_TPM_FINAL_LOG_GUID, "TPMFinalLog", &efi.tpm_final_log},
476 {LINUX_EFI_MEMRESERVE_TABLE_GUID, "MEMRESERVE", &efi.mem_reserve},
477#ifdef CONFIG_EFI_RCI2_TABLE
478 {DELLEMC_EFI_RCI2_TABLE_GUID, NULL, &rci2_table_phys},
479#endif
480 {NULL_GUID, NULL, NULL},
481};
482
483static __init int match_config_table(efi_guid_t *guid,
484 unsigned long table,
485 efi_config_table_type_t *table_types)
486{
487 int i;
488
489 if (table_types) {
490 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
491 if (!efi_guidcmp(*guid, table_types[i].guid)) {
492 *(table_types[i].ptr) = table;
493 if (table_types[i].name)
494 pr_cont(" %s=0x%lx ",
495 table_types[i].name, table);
496 return 1;
497 }
498 }
499 }
500
501 return 0;
502}
503
504int __init efi_config_parse_tables(void *config_tables, int count, int sz,
505 efi_config_table_type_t *arch_tables)
506{
507 void *tablep;
508 int i;
509
510 tablep = config_tables;
511 pr_info("");
512 for (i = 0; i < count; i++) {
513 efi_guid_t guid;
514 unsigned long table;
515
516 if (efi_enabled(EFI_64BIT)) {
517 u64 table64;
518 guid = ((efi_config_table_64_t *)tablep)->guid;
519 table64 = ((efi_config_table_64_t *)tablep)->table;
520 table = table64;
521#ifndef CONFIG_64BIT
522 if (table64 >> 32) {
523 pr_cont("\n");
524 pr_err("Table located above 4GB, disabling EFI.\n");
525 return -EINVAL;
526 }
527#endif
528 } else {
529 guid = ((efi_config_table_32_t *)tablep)->guid;
530 table = ((efi_config_table_32_t *)tablep)->table;
531 }
532
533 if (!match_config_table(&guid, table, common_tables))
534 match_config_table(&guid, table, arch_tables);
535
536 tablep += sz;
537 }
538 pr_cont("\n");
539 set_bit(EFI_CONFIG_TABLES, &efi.flags);
540
541 if (efi.rng_seed != EFI_INVALID_TABLE_ADDR) {
542 struct linux_efi_random_seed *seed;
543 u32 size = 0;
544
545 seed = early_memremap(efi.rng_seed, sizeof(*seed));
546 if (seed != NULL) {
547 size = seed->size;
548 early_memunmap(seed, sizeof(*seed));
549 } else {
550 pr_err("Could not map UEFI random seed!\n");
551 }
552 if (size > 0) {
553 seed = early_memremap(efi.rng_seed,
554 sizeof(*seed) + size);
555 if (seed != NULL) {
556 pr_notice("seeding entropy pool\n");
557 add_bootloader_randomness(seed->bits, seed->size);
558 early_memunmap(seed, sizeof(*seed) + size);
559 } else {
560 pr_err("Could not map UEFI random seed!\n");
561 }
562 }
563 }
564
565 if (efi_enabled(EFI_MEMMAP))
566 efi_memattr_init();
567
568 efi_tpm_eventlog_init();
569
570 /* Parse the EFI Properties table if it exists */
571 if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {
572 efi_properties_table_t *tbl;
573
574 tbl = early_memremap(efi.properties_table, sizeof(*tbl));
575 if (tbl == NULL) {
576 pr_err("Could not map Properties table!\n");
577 return -ENOMEM;
578 }
579
580 if (tbl->memory_protection_attribute &
581 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
582 set_bit(EFI_NX_PE_DATA, &efi.flags);
583
584 early_memunmap(tbl, sizeof(*tbl));
585 }
586
587 if (efi.mem_reserve != EFI_INVALID_TABLE_ADDR) {
588 unsigned long prsv = efi.mem_reserve;
589
590 while (prsv) {
591 struct linux_efi_memreserve *rsv;
592 u8 *p;
593 int i;
594
595 /*
596 * Just map a full page: that is what we will get
597 * anyway, and it permits us to map the entire entry
598 * before knowing its size.
599 */
600 p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
601 PAGE_SIZE);
602 if (p == NULL) {
603 pr_err("Could not map UEFI memreserve entry!\n");
604 return -ENOMEM;
605 }
606
607 rsv = (void *)(p + prsv % PAGE_SIZE);
608
609 /* reserve the entry itself */
610 memblock_reserve(prsv, EFI_MEMRESERVE_SIZE(rsv->size));
611
612 for (i = 0; i < atomic_read(&rsv->count); i++) {
613 memblock_reserve(rsv->entry[i].base,
614 rsv->entry[i].size);
615 }
616
617 prsv = rsv->next;
618 early_memunmap(p, PAGE_SIZE);
619 }
620 }
621
622 return 0;
623}
624
625int __init efi_config_init(efi_config_table_type_t *arch_tables)
626{
627 void *config_tables;
628 int sz, ret;
629
630 if (efi.systab->nr_tables == 0)
631 return 0;
632
633 if (efi_enabled(EFI_64BIT))
634 sz = sizeof(efi_config_table_64_t);
635 else
636 sz = sizeof(efi_config_table_32_t);
637
638 /*
639 * Let's see what config tables the firmware passed to us.
640 */
641 config_tables = early_memremap(efi.systab->tables,
642 efi.systab->nr_tables * sz);
643 if (config_tables == NULL) {
644 pr_err("Could not map Configuration table!\n");
645 return -ENOMEM;
646 }
647
648 ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
649 arch_tables);
650
651 early_memunmap(config_tables, efi.systab->nr_tables * sz);
652 return ret;
653}
654
655#ifdef CONFIG_EFI_VARS_MODULE
656static int __init efi_load_efivars(void)
657{
658 struct platform_device *pdev;
659
660 if (!efi_enabled(EFI_RUNTIME_SERVICES))
661 return 0;
662
663 pdev = platform_device_register_simple("efivars", 0, NULL, 0);
664 return PTR_ERR_OR_ZERO(pdev);
665}
666device_initcall(efi_load_efivars);
667#endif
668
669#ifdef CONFIG_EFI_PARAMS_FROM_FDT
670
671#define UEFI_PARAM(name, prop, field) \
672 { \
673 { name }, \
674 { prop }, \
675 offsetof(struct efi_fdt_params, field), \
676 FIELD_SIZEOF(struct efi_fdt_params, field) \
677 }
678
679struct params {
680 const char name[32];
681 const char propname[32];
682 int offset;
683 int size;
684};
685
686static __initdata struct params fdt_params[] = {
687 UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
688 UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
689 UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
690 UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
691 UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
692};
693
694static __initdata struct params xen_fdt_params[] = {
695 UEFI_PARAM("System Table", "xen,uefi-system-table", system_table),
696 UEFI_PARAM("MemMap Address", "xen,uefi-mmap-start", mmap),
697 UEFI_PARAM("MemMap Size", "xen,uefi-mmap-size", mmap_size),
698 UEFI_PARAM("MemMap Desc. Size", "xen,uefi-mmap-desc-size", desc_size),
699 UEFI_PARAM("MemMap Desc. Version", "xen,uefi-mmap-desc-ver", desc_ver)
700};
701
702#define EFI_FDT_PARAMS_SIZE ARRAY_SIZE(fdt_params)
703
704static __initdata struct {
705 const char *uname;
706 const char *subnode;
707 struct params *params;
708} dt_params[] = {
709 { "hypervisor", "uefi", xen_fdt_params },
710 { "chosen", NULL, fdt_params },
711};
712
713struct param_info {
714 int found;
715 void *params;
716 const char *missing;
717};
718
719static int __init __find_uefi_params(unsigned long node,
720 struct param_info *info,
721 struct params *params)
722{
723 const void *prop;
724 void *dest;
725 u64 val;
726 int i, len;
727
728 for (i = 0; i < EFI_FDT_PARAMS_SIZE; i++) {
729 prop = of_get_flat_dt_prop(node, params[i].propname, &len);
730 if (!prop) {
731 info->missing = params[i].name;
732 return 0;
733 }
734
735 dest = info->params + params[i].offset;
736 info->found++;
737
738 val = of_read_number(prop, len / sizeof(u32));
739
740 if (params[i].size == sizeof(u32))
741 *(u32 *)dest = val;
742 else
743 *(u64 *)dest = val;
744
745 if (efi_enabled(EFI_DBG))
746 pr_info(" %s: 0x%0*llx\n", params[i].name,
747 params[i].size * 2, val);
748 }
749
750 return 1;
751}
752
753static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
754 int depth, void *data)
755{
756 struct param_info *info = data;
757 int i;
758
759 for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
760 const char *subnode = dt_params[i].subnode;
761
762 if (depth != 1 || strcmp(uname, dt_params[i].uname) != 0) {
763 info->missing = dt_params[i].params[0].name;
764 continue;
765 }
766
767 if (subnode) {
768 int err = of_get_flat_dt_subnode_by_name(node, subnode);
769
770 if (err < 0)
771 return 0;
772
773 node = err;
774 }
775
776 return __find_uefi_params(node, info, dt_params[i].params);
777 }
778
779 return 0;
780}
781
782int __init efi_get_fdt_params(struct efi_fdt_params *params)
783{
784 struct param_info info;
785 int ret;
786
787 pr_info("Getting EFI parameters from FDT:\n");
788
789 info.found = 0;
790 info.params = params;
791
792 ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
793 if (!info.found)
794 pr_info("UEFI not found.\n");
795 else if (!ret)
796 pr_err("Can't find '%s' in device tree!\n",
797 info.missing);
798
799 return ret;
800}
801#endif /* CONFIG_EFI_PARAMS_FROM_FDT */
802
803static __initdata char memory_type_name[][20] = {
804 "Reserved",
805 "Loader Code",
806 "Loader Data",
807 "Boot Code",
808 "Boot Data",
809 "Runtime Code",
810 "Runtime Data",
811 "Conventional Memory",
812 "Unusable Memory",
813 "ACPI Reclaim Memory",
814 "ACPI Memory NVS",
815 "Memory Mapped I/O",
816 "MMIO Port Space",
817 "PAL Code",
818 "Persistent Memory",
819};
820
821char * __init efi_md_typeattr_format(char *buf, size_t size,
822 const efi_memory_desc_t *md)
823{
824 char *pos;
825 int type_len;
826 u64 attr;
827
828 pos = buf;
829 if (md->type >= ARRAY_SIZE(memory_type_name))
830 type_len = snprintf(pos, size, "[type=%u", md->type);
831 else
832 type_len = snprintf(pos, size, "[%-*s",
833 (int)(sizeof(memory_type_name[0]) - 1),
834 memory_type_name[md->type]);
835 if (type_len >= size)
836 return buf;
837
838 pos += type_len;
839 size -= type_len;
840
841 attr = md->attribute;
842 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
843 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
844 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
845 EFI_MEMORY_NV |
846 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
847 snprintf(pos, size, "|attr=0x%016llx]",
848 (unsigned long long)attr);
849 else
850 snprintf(pos, size,
851 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
852 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
853 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
854 attr & EFI_MEMORY_NV ? "NV" : "",
855 attr & EFI_MEMORY_XP ? "XP" : "",
856 attr & EFI_MEMORY_RP ? "RP" : "",
857 attr & EFI_MEMORY_WP ? "WP" : "",
858 attr & EFI_MEMORY_RO ? "RO" : "",
859 attr & EFI_MEMORY_UCE ? "UCE" : "",
860 attr & EFI_MEMORY_WB ? "WB" : "",
861 attr & EFI_MEMORY_WT ? "WT" : "",
862 attr & EFI_MEMORY_WC ? "WC" : "",
863 attr & EFI_MEMORY_UC ? "UC" : "");
864 return buf;
865}
866
867/*
868 * IA64 has a funky EFI memory map that doesn't work the same way as
869 * other architectures.
870 */
871#ifndef CONFIG_IA64
872/*
873 * efi_mem_attributes - lookup memmap attributes for physical address
874 * @phys_addr: the physical address to lookup
875 *
876 * Search in the EFI memory map for the region covering
877 * @phys_addr. Returns the EFI memory attributes if the region
878 * was found in the memory map, 0 otherwise.
879 */
880u64 efi_mem_attributes(unsigned long phys_addr)
881{
882 efi_memory_desc_t *md;
883
884 if (!efi_enabled(EFI_MEMMAP))
885 return 0;
886
887 for_each_efi_memory_desc(md) {
888 if ((md->phys_addr <= phys_addr) &&
889 (phys_addr < (md->phys_addr +
890 (md->num_pages << EFI_PAGE_SHIFT))))
891 return md->attribute;
892 }
893 return 0;
894}
895
896/*
897 * efi_mem_type - lookup memmap type for physical address
898 * @phys_addr: the physical address to lookup
899 *
900 * Search in the EFI memory map for the region covering @phys_addr.
901 * Returns the EFI memory type if the region was found in the memory
902 * map, EFI_RESERVED_TYPE (zero) otherwise.
903 */
904int efi_mem_type(unsigned long phys_addr)
905{
906 const efi_memory_desc_t *md;
907
908 if (!efi_enabled(EFI_MEMMAP))
909 return -ENOTSUPP;
910
911 for_each_efi_memory_desc(md) {
912 if ((md->phys_addr <= phys_addr) &&
913 (phys_addr < (md->phys_addr +
914 (md->num_pages << EFI_PAGE_SHIFT))))
915 return md->type;
916 }
917 return -EINVAL;
918}
919#endif
920
921int efi_status_to_err(efi_status_t status)
922{
923 int err;
924
925 switch (status) {
926 case EFI_SUCCESS:
927 err = 0;
928 break;
929 case EFI_INVALID_PARAMETER:
930 err = -EINVAL;
931 break;
932 case EFI_OUT_OF_RESOURCES:
933 err = -ENOSPC;
934 break;
935 case EFI_DEVICE_ERROR:
936 err = -EIO;
937 break;
938 case EFI_WRITE_PROTECTED:
939 err = -EROFS;
940 break;
941 case EFI_SECURITY_VIOLATION:
942 err = -EACCES;
943 break;
944 case EFI_NOT_FOUND:
945 err = -ENOENT;
946 break;
947 case EFI_ABORTED:
948 err = -EINTR;
949 break;
950 default:
951 err = -EINVAL;
952 }
953
954 return err;
955}
956
957static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
958static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
959
960static int __init efi_memreserve_map_root(void)
961{
962 if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
963 return -ENODEV;
964
965 efi_memreserve_root = memremap(efi.mem_reserve,
966 sizeof(*efi_memreserve_root),
967 MEMREMAP_WB);
968 if (WARN_ON_ONCE(!efi_memreserve_root))
969 return -ENOMEM;
970 return 0;
971}
972
973int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
974{
975 struct linux_efi_memreserve *rsv;
976 unsigned long prsv;
977 int rc, index;
978
979 if (efi_memreserve_root == (void *)ULONG_MAX)
980 return -ENODEV;
981
982 if (!efi_memreserve_root) {
983 rc = efi_memreserve_map_root();
984 if (rc)
985 return rc;
986 }
987
988 /* first try to find a slot in an existing linked list entry */
989 for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
990 rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
991 index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
992 if (index < rsv->size) {
993 rsv->entry[index].base = addr;
994 rsv->entry[index].size = size;
995
996 memunmap(rsv);
997 return 0;
998 }
999 memunmap(rsv);
1000 }
1001
1002 /* no slot found - allocate a new linked list entry */
1003 rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
1004 if (!rsv)
1005 return -ENOMEM;
1006
1007 /*
1008 * The memremap() call above assumes that a linux_efi_memreserve entry
1009 * never crosses a page boundary, so let's ensure that this remains true
1010 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
1011 * using SZ_4K explicitly in the size calculation below.
1012 */
1013 rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
1014 atomic_set(&rsv->count, 1);
1015 rsv->entry[0].base = addr;
1016 rsv->entry[0].size = size;
1017
1018 spin_lock(&efi_mem_reserve_persistent_lock);
1019 rsv->next = efi_memreserve_root->next;
1020 efi_memreserve_root->next = __pa(rsv);
1021 spin_unlock(&efi_mem_reserve_persistent_lock);
1022
1023 return 0;
1024}
1025
1026static int __init efi_memreserve_root_init(void)
1027{
1028 if (efi_memreserve_root)
1029 return 0;
1030 if (efi_memreserve_map_root())
1031 efi_memreserve_root = (void *)ULONG_MAX;
1032 return 0;
1033}
1034early_initcall(efi_memreserve_root_init);
1035
1036#ifdef CONFIG_KEXEC
1037static int update_efi_random_seed(struct notifier_block *nb,
1038 unsigned long code, void *unused)
1039{
1040 struct linux_efi_random_seed *seed;
1041 u32 size = 0;
1042
1043 if (!kexec_in_progress)
1044 return NOTIFY_DONE;
1045
1046 seed = memremap(efi.rng_seed, sizeof(*seed), MEMREMAP_WB);
1047 if (seed != NULL) {
1048 size = min(seed->size, EFI_RANDOM_SEED_SIZE);
1049 memunmap(seed);
1050 } else {
1051 pr_err("Could not map UEFI random seed!\n");
1052 }
1053 if (size > 0) {
1054 seed = memremap(efi.rng_seed, sizeof(*seed) + size,
1055 MEMREMAP_WB);
1056 if (seed != NULL) {
1057 seed->size = size;
1058 get_random_bytes(seed->bits, seed->size);
1059 memunmap(seed);
1060 } else {
1061 pr_err("Could not map UEFI random seed!\n");
1062 }
1063 }
1064 return NOTIFY_DONE;
1065}
1066
1067static struct notifier_block efi_random_seed_nb = {
1068 .notifier_call = update_efi_random_seed,
1069};
1070
1071static int register_update_efi_random_seed(void)
1072{
1073 if (efi.rng_seed == EFI_INVALID_TABLE_ADDR)
1074 return 0;
1075 return register_reboot_notifier(&efi_random_seed_nb);
1076}
1077late_initcall(register_update_efi_random_seed);
1078#endif