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