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