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 #include <linux/notifier.h>
36
37 #include <asm/early_ioremap.h>
38
39 struct efi __read_mostly efi = {
40 .runtime_supported_mask = EFI_RT_SUPPORTED_ALL,
41 .acpi = EFI_INVALID_TABLE_ADDR,
42 .acpi20 = EFI_INVALID_TABLE_ADDR,
43 .smbios = EFI_INVALID_TABLE_ADDR,
44 .smbios3 = EFI_INVALID_TABLE_ADDR,
45 .esrt = EFI_INVALID_TABLE_ADDR,
46 .tpm_log = EFI_INVALID_TABLE_ADDR,
47 .tpm_final_log = EFI_INVALID_TABLE_ADDR,
48 #ifdef CONFIG_LOAD_UEFI_KEYS
49 .mokvar_table = EFI_INVALID_TABLE_ADDR,
50 #endif
51 #ifdef CONFIG_EFI_COCO_SECRET
52 .coco_secret = EFI_INVALID_TABLE_ADDR,
53 #endif
54 #ifdef CONFIG_UNACCEPTED_MEMORY
55 .unaccepted = EFI_INVALID_TABLE_ADDR,
56 #endif
57 };
58 EXPORT_SYMBOL(efi);
59
60 unsigned long __ro_after_init efi_rng_seed = EFI_INVALID_TABLE_ADDR;
61 static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR;
62 static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR;
63 static unsigned long __initdata initrd = EFI_INVALID_TABLE_ADDR;
64
65 extern unsigned long screen_info_table;
66
67 struct mm_struct efi_mm = {
68 .mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, efi_mm.mmap_lock),
69 .mm_users = ATOMIC_INIT(2),
70 .mm_count = ATOMIC_INIT(1),
71 .write_protect_seq = SEQCNT_ZERO(efi_mm.write_protect_seq),
72 MMAP_LOCK_INITIALIZER(efi_mm)
73 .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
74 .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
75 .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0},
76 };
77
78 struct workqueue_struct *efi_rts_wq;
79
80 static bool disable_runtime = IS_ENABLED(CONFIG_EFI_DISABLE_RUNTIME);
setup_noefi(char * arg)81 static int __init setup_noefi(char *arg)
82 {
83 disable_runtime = true;
84 return 0;
85 }
86 early_param("noefi", setup_noefi);
87
efi_runtime_disabled(void)88 bool efi_runtime_disabled(void)
89 {
90 return disable_runtime;
91 }
92
__efi_soft_reserve_enabled(void)93 bool __pure __efi_soft_reserve_enabled(void)
94 {
95 return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE);
96 }
97
parse_efi_cmdline(char * str)98 static int __init parse_efi_cmdline(char *str)
99 {
100 if (!str) {
101 pr_warn("need at least one option\n");
102 return -EINVAL;
103 }
104
105 if (parse_option_str(str, "debug"))
106 set_bit(EFI_DBG, &efi.flags);
107
108 if (parse_option_str(str, "noruntime"))
109 disable_runtime = true;
110
111 if (parse_option_str(str, "runtime"))
112 disable_runtime = false;
113
114 if (parse_option_str(str, "nosoftreserve"))
115 set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags);
116
117 return 0;
118 }
119 early_param("efi", parse_efi_cmdline);
120
121 struct kobject *efi_kobj;
122
123 /*
124 * Let's not leave out systab information that snuck into
125 * the efivars driver
126 * Note, do not add more fields in systab sysfs file as it breaks sysfs
127 * one value per file rule!
128 */
systab_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)129 static ssize_t systab_show(struct kobject *kobj,
130 struct kobj_attribute *attr, char *buf)
131 {
132 char *str = buf;
133
134 if (!kobj || !buf)
135 return -EINVAL;
136
137 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
138 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
139 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
140 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
141 /*
142 * If both SMBIOS and SMBIOS3 entry points are implemented, the
143 * SMBIOS3 entry point shall be preferred, so we list it first to
144 * let applications stop parsing after the first match.
145 */
146 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
147 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
148 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
149 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
150
151 if (IS_ENABLED(CONFIG_X86))
152 str = efi_systab_show_arch(str);
153
154 return str - buf;
155 }
156
157 static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
158
fw_platform_size_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)159 static ssize_t fw_platform_size_show(struct kobject *kobj,
160 struct kobj_attribute *attr, char *buf)
161 {
162 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
163 }
164
165 extern __weak struct kobj_attribute efi_attr_fw_vendor;
166 extern __weak struct kobj_attribute efi_attr_runtime;
167 extern __weak struct kobj_attribute efi_attr_config_table;
168 static struct kobj_attribute efi_attr_fw_platform_size =
169 __ATTR_RO(fw_platform_size);
170
171 static struct attribute *efi_subsys_attrs[] = {
172 &efi_attr_systab.attr,
173 &efi_attr_fw_platform_size.attr,
174 &efi_attr_fw_vendor.attr,
175 &efi_attr_runtime.attr,
176 &efi_attr_config_table.attr,
177 NULL,
178 };
179
efi_attr_is_visible(struct kobject * kobj,struct attribute * attr,int n)180 umode_t __weak efi_attr_is_visible(struct kobject *kobj, struct attribute *attr,
181 int n)
182 {
183 return attr->mode;
184 }
185
186 static const struct attribute_group efi_subsys_attr_group = {
187 .attrs = efi_subsys_attrs,
188 .is_visible = efi_attr_is_visible,
189 };
190
191 struct blocking_notifier_head efivar_ops_nh;
192 EXPORT_SYMBOL_GPL(efivar_ops_nh);
193
194 static struct efivars generic_efivars;
195 static struct efivar_operations generic_ops;
196
generic_ops_supported(void)197 static bool generic_ops_supported(void)
198 {
199 unsigned long name_size;
200 efi_status_t status;
201 efi_char16_t name;
202 efi_guid_t guid;
203
204 name_size = sizeof(name);
205
206 if (!efi.get_next_variable)
207 return false;
208 status = efi.get_next_variable(&name_size, &name, &guid);
209 if (status == EFI_UNSUPPORTED)
210 return false;
211
212 return true;
213 }
214
generic_ops_register(void)215 static int generic_ops_register(void)
216 {
217 if (!generic_ops_supported())
218 return 0;
219
220 generic_ops.get_variable = efi.get_variable;
221 generic_ops.get_next_variable = efi.get_next_variable;
222 generic_ops.query_variable_store = efi_query_variable_store;
223 generic_ops.query_variable_info = efi.query_variable_info;
224
225 if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) {
226 generic_ops.set_variable = efi.set_variable;
227 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
228 }
229 return efivars_register(&generic_efivars, &generic_ops);
230 }
231
generic_ops_unregister(void)232 static void generic_ops_unregister(void)
233 {
234 if (!generic_ops.get_variable)
235 return;
236
237 efivars_unregister(&generic_efivars);
238 }
239
efivars_generic_ops_register(void)240 void efivars_generic_ops_register(void)
241 {
242 generic_ops_register();
243 }
244 EXPORT_SYMBOL_GPL(efivars_generic_ops_register);
245
efivars_generic_ops_unregister(void)246 void efivars_generic_ops_unregister(void)
247 {
248 generic_ops_unregister();
249 }
250 EXPORT_SYMBOL_GPL(efivars_generic_ops_unregister);
251
252 #ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS
253 #define EFIVAR_SSDT_NAME_MAX 16UL
254 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
efivar_ssdt_setup(char * str)255 static int __init efivar_ssdt_setup(char *str)
256 {
257 int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
258
259 if (ret)
260 return ret;
261
262 if (strlen(str) < sizeof(efivar_ssdt))
263 memcpy(efivar_ssdt, str, strlen(str));
264 else
265 pr_warn("efivar_ssdt: name too long: %s\n", str);
266 return 1;
267 }
268 __setup("efivar_ssdt=", efivar_ssdt_setup);
269
efivar_ssdt_load(void)270 static __init int efivar_ssdt_load(void)
271 {
272 unsigned long name_size = 256;
273 efi_char16_t *name = NULL;
274 efi_status_t status;
275 efi_guid_t guid;
276
277 if (!efivar_ssdt[0])
278 return 0;
279
280 name = kzalloc(name_size, GFP_KERNEL);
281 if (!name)
282 return -ENOMEM;
283
284 for (;;) {
285 char utf8_name[EFIVAR_SSDT_NAME_MAX];
286 unsigned long data_size = 0;
287 void *data;
288 int limit;
289
290 status = efi.get_next_variable(&name_size, name, &guid);
291 if (status == EFI_NOT_FOUND) {
292 break;
293 } else if (status == EFI_BUFFER_TOO_SMALL) {
294 efi_char16_t *name_tmp =
295 krealloc(name, name_size, GFP_KERNEL);
296 if (!name_tmp) {
297 kfree(name);
298 return -ENOMEM;
299 }
300 name = name_tmp;
301 continue;
302 }
303
304 limit = min(EFIVAR_SSDT_NAME_MAX, name_size);
305 ucs2_as_utf8(utf8_name, name, limit - 1);
306 if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
307 continue;
308
309 pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt, &guid);
310
311 status = efi.get_variable(name, &guid, NULL, &data_size, NULL);
312 if (status != EFI_BUFFER_TOO_SMALL || !data_size)
313 return -EIO;
314
315 data = kmalloc(data_size, GFP_KERNEL);
316 if (!data)
317 return -ENOMEM;
318
319 status = efi.get_variable(name, &guid, NULL, &data_size, data);
320 if (status == EFI_SUCCESS) {
321 acpi_status ret = acpi_load_table(data, NULL);
322 if (ret)
323 pr_err("failed to load table: %u\n", ret);
324 else
325 continue;
326 } else {
327 pr_err("failed to get var data: 0x%lx\n", status);
328 }
329 kfree(data);
330 }
331 return 0;
332 }
333 #else
efivar_ssdt_load(void)334 static inline int efivar_ssdt_load(void) { return 0; }
335 #endif
336
337 #ifdef CONFIG_DEBUG_FS
338
339 #define EFI_DEBUGFS_MAX_BLOBS 32
340
341 static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS];
342
efi_debugfs_init(void)343 static void __init efi_debugfs_init(void)
344 {
345 struct dentry *efi_debugfs;
346 efi_memory_desc_t *md;
347 char name[32];
348 int type_count[EFI_BOOT_SERVICES_DATA + 1] = {};
349 int i = 0;
350
351 efi_debugfs = debugfs_create_dir("efi", NULL);
352 if (IS_ERR(efi_debugfs))
353 return;
354
355 for_each_efi_memory_desc(md) {
356 switch (md->type) {
357 case EFI_BOOT_SERVICES_CODE:
358 snprintf(name, sizeof(name), "boot_services_code%d",
359 type_count[md->type]++);
360 break;
361 case EFI_BOOT_SERVICES_DATA:
362 snprintf(name, sizeof(name), "boot_services_data%d",
363 type_count[md->type]++);
364 break;
365 default:
366 continue;
367 }
368
369 if (i >= EFI_DEBUGFS_MAX_BLOBS) {
370 pr_warn("More then %d EFI boot service segments, only showing first %d in debugfs\n",
371 EFI_DEBUGFS_MAX_BLOBS, EFI_DEBUGFS_MAX_BLOBS);
372 break;
373 }
374
375 debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT;
376 debugfs_blob[i].data = memremap(md->phys_addr,
377 debugfs_blob[i].size,
378 MEMREMAP_WB);
379 if (!debugfs_blob[i].data)
380 continue;
381
382 debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]);
383 i++;
384 }
385 }
386 #else
efi_debugfs_init(void)387 static inline void efi_debugfs_init(void) {}
388 #endif
389
390 /*
391 * We register the efi subsystem with the firmware subsystem and the
392 * efivars subsystem with the efi subsystem, if the system was booted with
393 * EFI.
394 */
efisubsys_init(void)395 static int __init efisubsys_init(void)
396 {
397 int error;
398
399 if (!efi_enabled(EFI_RUNTIME_SERVICES))
400 efi.runtime_supported_mask = 0;
401
402 if (!efi_enabled(EFI_BOOT))
403 return 0;
404
405 if (efi.runtime_supported_mask) {
406 /*
407 * Since we process only one efi_runtime_service() at a time, an
408 * ordered workqueue (which creates only one execution context)
409 * should suffice for all our needs.
410 */
411 efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
412 if (!efi_rts_wq) {
413 pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
414 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
415 efi.runtime_supported_mask = 0;
416 return 0;
417 }
418 }
419
420 if (efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES))
421 platform_device_register_simple("rtc-efi", 0, NULL, 0);
422
423 /* We register the efi directory at /sys/firmware/efi */
424 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
425 if (!efi_kobj) {
426 pr_err("efi: Firmware registration failed.\n");
427 error = -ENOMEM;
428 goto err_destroy_wq;
429 }
430
431 if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
432 EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) {
433 error = generic_ops_register();
434 if (error)
435 goto err_put;
436 efivar_ssdt_load();
437 platform_device_register_simple("efivars", 0, NULL, 0);
438 }
439
440 BLOCKING_INIT_NOTIFIER_HEAD(&efivar_ops_nh);
441
442 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
443 if (error) {
444 pr_err("efi: Sysfs attribute export failed with error %d.\n",
445 error);
446 goto err_unregister;
447 }
448
449 /* and the standard mountpoint for efivarfs */
450 error = sysfs_create_mount_point(efi_kobj, "efivars");
451 if (error) {
452 pr_err("efivars: Subsystem registration failed.\n");
453 goto err_remove_group;
454 }
455
456 if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
457 efi_debugfs_init();
458
459 #ifdef CONFIG_EFI_COCO_SECRET
460 if (efi.coco_secret != EFI_INVALID_TABLE_ADDR)
461 platform_device_register_simple("efi_secret", 0, NULL, 0);
462 #endif
463
464 return 0;
465
466 err_remove_group:
467 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
468 err_unregister:
469 if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
470 EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME))
471 generic_ops_unregister();
472 err_put:
473 kobject_put(efi_kobj);
474 efi_kobj = NULL;
475 err_destroy_wq:
476 if (efi_rts_wq)
477 destroy_workqueue(efi_rts_wq);
478
479 return error;
480 }
481
482 subsys_initcall(efisubsys_init);
483
efi_find_mirror(void)484 void __init efi_find_mirror(void)
485 {
486 efi_memory_desc_t *md;
487 u64 mirror_size = 0, total_size = 0;
488
489 if (!efi_enabled(EFI_MEMMAP))
490 return;
491
492 for_each_efi_memory_desc(md) {
493 unsigned long long start = md->phys_addr;
494 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
495
496 total_size += size;
497 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
498 memblock_mark_mirror(start, size);
499 mirror_size += size;
500 }
501 }
502 if (mirror_size)
503 pr_info("Memory: %lldM/%lldM mirrored memory\n",
504 mirror_size>>20, total_size>>20);
505 }
506
507 /*
508 * Find the efi memory descriptor for a given physical address. Given a
509 * physical address, determine if it exists within an EFI Memory Map entry,
510 * and if so, populate the supplied memory descriptor with the appropriate
511 * data.
512 */
__efi_mem_desc_lookup(u64 phys_addr,efi_memory_desc_t * out_md)513 int __efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
514 {
515 efi_memory_desc_t *md;
516
517 if (!efi_enabled(EFI_MEMMAP)) {
518 pr_err_once("EFI_MEMMAP is not enabled.\n");
519 return -EINVAL;
520 }
521
522 if (!out_md) {
523 pr_err_once("out_md is null.\n");
524 return -EINVAL;
525 }
526
527 for_each_efi_memory_desc(md) {
528 u64 size;
529 u64 end;
530
531 /* skip bogus entries (including empty ones) */
532 if ((md->phys_addr & (EFI_PAGE_SIZE - 1)) ||
533 (md->num_pages <= 0) ||
534 (md->num_pages > (U64_MAX - md->phys_addr) >> EFI_PAGE_SHIFT))
535 continue;
536
537 size = md->num_pages << EFI_PAGE_SHIFT;
538 end = md->phys_addr + size;
539 if (phys_addr >= md->phys_addr && phys_addr < end) {
540 memcpy(out_md, md, sizeof(*out_md));
541 return 0;
542 }
543 }
544 return -ENOENT;
545 }
546
547 extern int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
548 __weak __alias(__efi_mem_desc_lookup);
549
550 /*
551 * Calculate the highest address of an efi memory descriptor.
552 */
efi_mem_desc_end(efi_memory_desc_t * md)553 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
554 {
555 u64 size = md->num_pages << EFI_PAGE_SHIFT;
556 u64 end = md->phys_addr + size;
557 return end;
558 }
559
efi_arch_mem_reserve(phys_addr_t addr,u64 size)560 void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
561
562 /**
563 * efi_mem_reserve - Reserve an EFI memory region
564 * @addr: Physical address to reserve
565 * @size: Size of reservation
566 *
567 * Mark a region as reserved from general kernel allocation and
568 * prevent it being released by efi_free_boot_services().
569 *
570 * This function should be called drivers once they've parsed EFI
571 * configuration tables to figure out where their data lives, e.g.
572 * efi_esrt_init().
573 */
efi_mem_reserve(phys_addr_t addr,u64 size)574 void __init efi_mem_reserve(phys_addr_t addr, u64 size)
575 {
576 /* efi_mem_reserve() does not work under Xen */
577 if (WARN_ON_ONCE(efi_enabled(EFI_PARAVIRT)))
578 return;
579
580 if (!memblock_is_region_reserved(addr, size))
581 memblock_reserve(addr, size);
582
583 /*
584 * Some architectures (x86) reserve all boot services ranges
585 * until efi_free_boot_services() because of buggy firmware
586 * implementations. This means the above memblock_reserve() is
587 * superfluous on x86 and instead what it needs to do is
588 * ensure the @start, @size is not freed.
589 */
590 efi_arch_mem_reserve(addr, size);
591 }
592
593 static const efi_config_table_type_t common_tables[] __initconst = {
594 {ACPI_20_TABLE_GUID, &efi.acpi20, "ACPI 2.0" },
595 {ACPI_TABLE_GUID, &efi.acpi, "ACPI" },
596 {SMBIOS_TABLE_GUID, &efi.smbios, "SMBIOS" },
597 {SMBIOS3_TABLE_GUID, &efi.smbios3, "SMBIOS 3.0" },
598 {EFI_SYSTEM_RESOURCE_TABLE_GUID, &efi.esrt, "ESRT" },
599 {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, &efi_mem_attr_table, "MEMATTR" },
600 {LINUX_EFI_RANDOM_SEED_TABLE_GUID, &efi_rng_seed, "RNG" },
601 {LINUX_EFI_TPM_EVENT_LOG_GUID, &efi.tpm_log, "TPMEventLog" },
602 {EFI_TCG2_FINAL_EVENTS_TABLE_GUID, &efi.tpm_final_log, "TPMFinalLog" },
603 {EFI_CC_FINAL_EVENTS_TABLE_GUID, &efi.tpm_final_log, "CCFinalLog" },
604 {LINUX_EFI_MEMRESERVE_TABLE_GUID, &mem_reserve, "MEMRESERVE" },
605 {LINUX_EFI_INITRD_MEDIA_GUID, &initrd, "INITRD" },
606 {EFI_RT_PROPERTIES_TABLE_GUID, &rt_prop, "RTPROP" },
607 #ifdef CONFIG_EFI_RCI2_TABLE
608 {DELLEMC_EFI_RCI2_TABLE_GUID, &rci2_table_phys },
609 #endif
610 #ifdef CONFIG_LOAD_UEFI_KEYS
611 {LINUX_EFI_MOK_VARIABLE_TABLE_GUID, &efi.mokvar_table, "MOKvar" },
612 #endif
613 #ifdef CONFIG_EFI_COCO_SECRET
614 {LINUX_EFI_COCO_SECRET_AREA_GUID, &efi.coco_secret, "CocoSecret" },
615 #endif
616 #ifdef CONFIG_UNACCEPTED_MEMORY
617 {LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID, &efi.unaccepted, "Unaccepted" },
618 #endif
619 #ifdef CONFIG_EFI_GENERIC_STUB
620 {LINUX_EFI_SCREEN_INFO_TABLE_GUID, &screen_info_table },
621 #endif
622 {},
623 };
624
match_config_table(const efi_guid_t * guid,unsigned long table,const efi_config_table_type_t * table_types)625 static __init int match_config_table(const efi_guid_t *guid,
626 unsigned long table,
627 const efi_config_table_type_t *table_types)
628 {
629 int i;
630
631 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
632 if (efi_guidcmp(*guid, table_types[i].guid))
633 continue;
634
635 if (!efi_config_table_is_usable(guid, table)) {
636 if (table_types[i].name[0])
637 pr_cont("(%s=0x%lx unusable) ",
638 table_types[i].name, table);
639 return 1;
640 }
641
642 *(table_types[i].ptr) = table;
643 if (table_types[i].name[0])
644 pr_cont("%s=0x%lx ", table_types[i].name, table);
645 return 1;
646 }
647
648 return 0;
649 }
650
651 /**
652 * reserve_unaccepted - Map and reserve unaccepted configuration table
653 * @unaccepted: Pointer to unaccepted memory table
654 *
655 * memblock_add() makes sure that the table is mapped in direct mapping. During
656 * normal boot it happens automatically because the table is allocated from
657 * usable memory. But during crashkernel boot only memory specifically reserved
658 * for crash scenario is mapped. memblock_add() forces the table to be mapped
659 * in crashkernel case.
660 *
661 * Align the range to the nearest page borders. Ranges smaller than page size
662 * are not going to be mapped.
663 *
664 * memblock_reserve() makes sure that future allocations will not touch the
665 * table.
666 */
667
reserve_unaccepted(struct efi_unaccepted_memory * unaccepted)668 static __init void reserve_unaccepted(struct efi_unaccepted_memory *unaccepted)
669 {
670 phys_addr_t start, size;
671
672 start = PAGE_ALIGN_DOWN(efi.unaccepted);
673 size = PAGE_ALIGN(sizeof(*unaccepted) + unaccepted->size);
674
675 memblock_add(start, size);
676 memblock_reserve(start, size);
677 }
678
efi_config_parse_tables(const efi_config_table_t * config_tables,int count,const efi_config_table_type_t * arch_tables)679 int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
680 int count,
681 const efi_config_table_type_t *arch_tables)
682 {
683 const efi_config_table_64_t *tbl64 = (void *)config_tables;
684 const efi_config_table_32_t *tbl32 = (void *)config_tables;
685 const efi_guid_t *guid;
686 unsigned long table;
687 int i;
688
689 pr_info("");
690 for (i = 0; i < count; i++) {
691 if (!IS_ENABLED(CONFIG_X86)) {
692 guid = &config_tables[i].guid;
693 table = (unsigned long)config_tables[i].table;
694 } else if (efi_enabled(EFI_64BIT)) {
695 guid = &tbl64[i].guid;
696 table = tbl64[i].table;
697
698 if (IS_ENABLED(CONFIG_X86_32) &&
699 tbl64[i].table > U32_MAX) {
700 pr_cont("\n");
701 pr_err("Table located above 4GB, disabling EFI.\n");
702 return -EINVAL;
703 }
704 } else {
705 guid = &tbl32[i].guid;
706 table = tbl32[i].table;
707 }
708
709 if (!match_config_table(guid, table, common_tables) && arch_tables)
710 match_config_table(guid, table, arch_tables);
711 }
712 pr_cont("\n");
713 set_bit(EFI_CONFIG_TABLES, &efi.flags);
714
715 if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) {
716 struct linux_efi_random_seed *seed;
717 u32 size = 0;
718
719 seed = early_memremap(efi_rng_seed, sizeof(*seed));
720 if (seed != NULL) {
721 size = min_t(u32, seed->size, SZ_1K); // sanity check
722 early_memunmap(seed, sizeof(*seed));
723 } else {
724 pr_err("Could not map UEFI random seed!\n");
725 }
726 if (size > 0) {
727 seed = early_memremap(efi_rng_seed,
728 sizeof(*seed) + size);
729 if (seed != NULL) {
730 add_bootloader_randomness(seed->bits, size);
731 memzero_explicit(seed->bits, size);
732 early_memunmap(seed, sizeof(*seed) + size);
733 } else {
734 pr_err("Could not map UEFI random seed!\n");
735 }
736 }
737 }
738
739 if (!IS_ENABLED(CONFIG_X86_32) && efi_enabled(EFI_MEMMAP))
740 efi_memattr_init();
741
742 efi_tpm_eventlog_init();
743
744 if (mem_reserve != EFI_INVALID_TABLE_ADDR) {
745 unsigned long prsv = mem_reserve;
746
747 while (prsv) {
748 struct linux_efi_memreserve *rsv;
749 u8 *p;
750
751 /*
752 * Just map a full page: that is what we will get
753 * anyway, and it permits us to map the entire entry
754 * before knowing its size.
755 */
756 p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
757 PAGE_SIZE);
758 if (p == NULL) {
759 pr_err("Could not map UEFI memreserve entry!\n");
760 return -ENOMEM;
761 }
762
763 rsv = (void *)(p + prsv % PAGE_SIZE);
764
765 /* reserve the entry itself */
766 memblock_reserve(prsv,
767 struct_size(rsv, entry, rsv->size));
768
769 for (i = 0; i < atomic_read(&rsv->count); i++) {
770 memblock_reserve(rsv->entry[i].base,
771 rsv->entry[i].size);
772 }
773
774 prsv = rsv->next;
775 early_memunmap(p, PAGE_SIZE);
776 }
777 }
778
779 if (rt_prop != EFI_INVALID_TABLE_ADDR) {
780 efi_rt_properties_table_t *tbl;
781
782 tbl = early_memremap(rt_prop, sizeof(*tbl));
783 if (tbl) {
784 efi.runtime_supported_mask &= tbl->runtime_services_supported;
785 early_memunmap(tbl, sizeof(*tbl));
786 }
787 }
788
789 if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) &&
790 initrd != EFI_INVALID_TABLE_ADDR && phys_initrd_size == 0) {
791 struct linux_efi_initrd *tbl;
792
793 tbl = early_memremap(initrd, sizeof(*tbl));
794 if (tbl) {
795 phys_initrd_start = tbl->base;
796 phys_initrd_size = tbl->size;
797 early_memunmap(tbl, sizeof(*tbl));
798 }
799 }
800
801 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) &&
802 efi.unaccepted != EFI_INVALID_TABLE_ADDR) {
803 struct efi_unaccepted_memory *unaccepted;
804
805 unaccepted = early_memremap(efi.unaccepted, sizeof(*unaccepted));
806 if (unaccepted) {
807
808 if (unaccepted->version == 1) {
809 reserve_unaccepted(unaccepted);
810 } else {
811 efi.unaccepted = EFI_INVALID_TABLE_ADDR;
812 }
813
814 early_memunmap(unaccepted, sizeof(*unaccepted));
815 }
816 }
817
818 return 0;
819 }
820
efi_systab_check_header(const efi_table_hdr_t * systab_hdr)821 int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr)
822 {
823 if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) {
824 pr_err("System table signature incorrect!\n");
825 return -EINVAL;
826 }
827
828 return 0;
829 }
830
map_fw_vendor(unsigned long fw_vendor,size_t size)831 static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor,
832 size_t size)
833 {
834 const efi_char16_t *ret;
835
836 ret = early_memremap_ro(fw_vendor, size);
837 if (!ret)
838 pr_err("Could not map the firmware vendor!\n");
839 return ret;
840 }
841
unmap_fw_vendor(const void * fw_vendor,size_t size)842 static void __init unmap_fw_vendor(const void *fw_vendor, size_t size)
843 {
844 early_memunmap((void *)fw_vendor, size);
845 }
846
efi_systab_report_header(const efi_table_hdr_t * systab_hdr,unsigned long fw_vendor)847 void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
848 unsigned long fw_vendor)
849 {
850 char vendor[100] = "unknown";
851 const efi_char16_t *c16;
852 size_t i;
853 u16 rev;
854
855 c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t));
856 if (c16) {
857 for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
858 vendor[i] = c16[i];
859 vendor[i] = '\0';
860
861 unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t));
862 }
863
864 rev = (u16)systab_hdr->revision;
865 pr_info("EFI v%u.%u", systab_hdr->revision >> 16, rev / 10);
866
867 rev %= 10;
868 if (rev)
869 pr_cont(".%u", rev);
870
871 pr_cont(" by %s\n", vendor);
872
873 if (IS_ENABLED(CONFIG_X86_64) &&
874 systab_hdr->revision > EFI_1_10_SYSTEM_TABLE_REVISION &&
875 !strcmp(vendor, "Apple")) {
876 pr_info("Apple Mac detected, using EFI v1.10 runtime services only\n");
877 efi.runtime_version = EFI_1_10_SYSTEM_TABLE_REVISION;
878 }
879 }
880
881 static __initdata char memory_type_name[][13] = {
882 "Reserved",
883 "Loader Code",
884 "Loader Data",
885 "Boot Code",
886 "Boot Data",
887 "Runtime Code",
888 "Runtime Data",
889 "Conventional",
890 "Unusable",
891 "ACPI Reclaim",
892 "ACPI Mem NVS",
893 "MMIO",
894 "MMIO Port",
895 "PAL Code",
896 "Persistent",
897 "Unaccepted",
898 };
899
efi_md_typeattr_format(char * buf,size_t size,const efi_memory_desc_t * md)900 char * __init efi_md_typeattr_format(char *buf, size_t size,
901 const efi_memory_desc_t *md)
902 {
903 char *pos;
904 int type_len;
905 u64 attr;
906
907 pos = buf;
908 if (md->type >= ARRAY_SIZE(memory_type_name))
909 type_len = snprintf(pos, size, "[type=%u", md->type);
910 else
911 type_len = snprintf(pos, size, "[%-*s",
912 (int)(sizeof(memory_type_name[0]) - 1),
913 memory_type_name[md->type]);
914 if (type_len >= size)
915 return buf;
916
917 pos += type_len;
918 size -= type_len;
919
920 attr = md->attribute;
921 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
922 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
923 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
924 EFI_MEMORY_NV | EFI_MEMORY_SP | EFI_MEMORY_CPU_CRYPTO |
925 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
926 snprintf(pos, size, "|attr=0x%016llx]",
927 (unsigned long long)attr);
928 else
929 snprintf(pos, size,
930 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
931 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
932 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
933 attr & EFI_MEMORY_CPU_CRYPTO ? "CC" : "",
934 attr & EFI_MEMORY_SP ? "SP" : "",
935 attr & EFI_MEMORY_NV ? "NV" : "",
936 attr & EFI_MEMORY_XP ? "XP" : "",
937 attr & EFI_MEMORY_RP ? "RP" : "",
938 attr & EFI_MEMORY_WP ? "WP" : "",
939 attr & EFI_MEMORY_RO ? "RO" : "",
940 attr & EFI_MEMORY_UCE ? "UCE" : "",
941 attr & EFI_MEMORY_WB ? "WB" : "",
942 attr & EFI_MEMORY_WT ? "WT" : "",
943 attr & EFI_MEMORY_WC ? "WC" : "",
944 attr & EFI_MEMORY_UC ? "UC" : "");
945 return buf;
946 }
947
948 /*
949 * efi_mem_attributes - lookup memmap attributes for physical address
950 * @phys_addr: the physical address to lookup
951 *
952 * Search in the EFI memory map for the region covering
953 * @phys_addr. Returns the EFI memory attributes if the region
954 * was found in the memory map, 0 otherwise.
955 */
efi_mem_attributes(unsigned long phys_addr)956 u64 efi_mem_attributes(unsigned long phys_addr)
957 {
958 efi_memory_desc_t *md;
959
960 if (!efi_enabled(EFI_MEMMAP))
961 return 0;
962
963 for_each_efi_memory_desc(md) {
964 if ((md->phys_addr <= phys_addr) &&
965 (phys_addr < (md->phys_addr +
966 (md->num_pages << EFI_PAGE_SHIFT))))
967 return md->attribute;
968 }
969 return 0;
970 }
971
972 /*
973 * efi_mem_type - lookup memmap type for physical address
974 * @phys_addr: the physical address to lookup
975 *
976 * Search in the EFI memory map for the region covering @phys_addr.
977 * Returns the EFI memory type if the region was found in the memory
978 * map, -EINVAL otherwise.
979 */
efi_mem_type(unsigned long phys_addr)980 int efi_mem_type(unsigned long phys_addr)
981 {
982 const efi_memory_desc_t *md;
983
984 if (!efi_enabled(EFI_MEMMAP))
985 return -ENOTSUPP;
986
987 for_each_efi_memory_desc(md) {
988 if ((md->phys_addr <= phys_addr) &&
989 (phys_addr < (md->phys_addr +
990 (md->num_pages << EFI_PAGE_SHIFT))))
991 return md->type;
992 }
993 return -EINVAL;
994 }
995
efi_status_to_err(efi_status_t status)996 int efi_status_to_err(efi_status_t status)
997 {
998 int err;
999
1000 switch (status) {
1001 case EFI_SUCCESS:
1002 err = 0;
1003 break;
1004 case EFI_INVALID_PARAMETER:
1005 err = -EINVAL;
1006 break;
1007 case EFI_OUT_OF_RESOURCES:
1008 err = -ENOSPC;
1009 break;
1010 case EFI_DEVICE_ERROR:
1011 err = -EIO;
1012 break;
1013 case EFI_WRITE_PROTECTED:
1014 err = -EROFS;
1015 break;
1016 case EFI_SECURITY_VIOLATION:
1017 err = -EACCES;
1018 break;
1019 case EFI_NOT_FOUND:
1020 err = -ENOENT;
1021 break;
1022 case EFI_ABORTED:
1023 err = -EINTR;
1024 break;
1025 default:
1026 err = -EINVAL;
1027 }
1028
1029 return err;
1030 }
1031 EXPORT_SYMBOL_GPL(efi_status_to_err);
1032
1033 static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
1034 static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
1035
efi_memreserve_map_root(void)1036 static int __init efi_memreserve_map_root(void)
1037 {
1038 if (mem_reserve == EFI_INVALID_TABLE_ADDR)
1039 return -ENODEV;
1040
1041 efi_memreserve_root = memremap(mem_reserve,
1042 sizeof(*efi_memreserve_root),
1043 MEMREMAP_WB);
1044 if (WARN_ON_ONCE(!efi_memreserve_root))
1045 return -ENOMEM;
1046 return 0;
1047 }
1048
efi_mem_reserve_iomem(phys_addr_t addr,u64 size)1049 static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size)
1050 {
1051 struct resource *res, *parent;
1052 int ret;
1053
1054 res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
1055 if (!res)
1056 return -ENOMEM;
1057
1058 res->name = "reserved";
1059 res->flags = IORESOURCE_MEM;
1060 res->start = addr;
1061 res->end = addr + size - 1;
1062
1063 /* we expect a conflict with a 'System RAM' region */
1064 parent = request_resource_conflict(&iomem_resource, res);
1065 ret = parent ? request_resource(parent, res) : 0;
1066
1067 /*
1068 * Given that efi_mem_reserve_iomem() can be called at any
1069 * time, only call memblock_reserve() if the architecture
1070 * keeps the infrastructure around.
1071 */
1072 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK) && !ret)
1073 memblock_reserve(addr, size);
1074
1075 return ret;
1076 }
1077
efi_mem_reserve_persistent(phys_addr_t addr,u64 size)1078 int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
1079 {
1080 struct linux_efi_memreserve *rsv;
1081 unsigned long prsv;
1082 int rc, index;
1083
1084 if (efi_memreserve_root == (void *)ULONG_MAX)
1085 return -ENODEV;
1086
1087 if (!efi_memreserve_root) {
1088 rc = efi_memreserve_map_root();
1089 if (rc)
1090 return rc;
1091 }
1092
1093 /* first try to find a slot in an existing linked list entry */
1094 for (prsv = efi_memreserve_root->next; prsv; ) {
1095 rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
1096 if (!rsv)
1097 return -ENOMEM;
1098 index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
1099 if (index < rsv->size) {
1100 rsv->entry[index].base = addr;
1101 rsv->entry[index].size = size;
1102
1103 memunmap(rsv);
1104 return efi_mem_reserve_iomem(addr, size);
1105 }
1106 prsv = rsv->next;
1107 memunmap(rsv);
1108 }
1109
1110 /* no slot found - allocate a new linked list entry */
1111 rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
1112 if (!rsv)
1113 return -ENOMEM;
1114
1115 rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K);
1116 if (rc) {
1117 free_page((unsigned long)rsv);
1118 return rc;
1119 }
1120
1121 /*
1122 * The memremap() call above assumes that a linux_efi_memreserve entry
1123 * never crosses a page boundary, so let's ensure that this remains true
1124 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
1125 * using SZ_4K explicitly in the size calculation below.
1126 */
1127 rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
1128 atomic_set(&rsv->count, 1);
1129 rsv->entry[0].base = addr;
1130 rsv->entry[0].size = size;
1131
1132 spin_lock(&efi_mem_reserve_persistent_lock);
1133 rsv->next = efi_memreserve_root->next;
1134 efi_memreserve_root->next = __pa(rsv);
1135 spin_unlock(&efi_mem_reserve_persistent_lock);
1136
1137 return efi_mem_reserve_iomem(addr, size);
1138 }
1139
efi_memreserve_root_init(void)1140 static int __init efi_memreserve_root_init(void)
1141 {
1142 if (efi_memreserve_root)
1143 return 0;
1144 if (efi_memreserve_map_root())
1145 efi_memreserve_root = (void *)ULONG_MAX;
1146 return 0;
1147 }
1148 early_initcall(efi_memreserve_root_init);
1149
1150 #ifdef CONFIG_KEXEC
update_efi_random_seed(struct notifier_block * nb,unsigned long code,void * unused)1151 static int update_efi_random_seed(struct notifier_block *nb,
1152 unsigned long code, void *unused)
1153 {
1154 struct linux_efi_random_seed *seed;
1155 u32 size = 0;
1156
1157 if (!kexec_in_progress)
1158 return NOTIFY_DONE;
1159
1160 seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB);
1161 if (seed != NULL) {
1162 size = min(seed->size, EFI_RANDOM_SEED_SIZE);
1163 memunmap(seed);
1164 } else {
1165 pr_err("Could not map UEFI random seed!\n");
1166 }
1167 if (size > 0) {
1168 seed = memremap(efi_rng_seed, sizeof(*seed) + size,
1169 MEMREMAP_WB);
1170 if (seed != NULL) {
1171 seed->size = size;
1172 get_random_bytes(seed->bits, seed->size);
1173 memunmap(seed);
1174 } else {
1175 pr_err("Could not map UEFI random seed!\n");
1176 }
1177 }
1178 return NOTIFY_DONE;
1179 }
1180
1181 static struct notifier_block efi_random_seed_nb = {
1182 .notifier_call = update_efi_random_seed,
1183 };
1184
register_update_efi_random_seed(void)1185 static int __init register_update_efi_random_seed(void)
1186 {
1187 if (efi_rng_seed == EFI_INVALID_TABLE_ADDR)
1188 return 0;
1189 return register_reboot_notifier(&efi_random_seed_nb);
1190 }
1191 late_initcall(register_update_efi_random_seed);
1192 #endif
1193