1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * efi.c - EFI subsystem 4 * 5 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com> 6 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com> 7 * Copyright (C) 2013 Tom Gundersen <teg@jklm.no> 8 * 9 * This code registers /sys/firmware/efi{,/efivars} when EFI is supported, 10 * allowing the efivarfs to be mounted or the efivars module to be loaded. 11 * The existance of /sys/firmware/efi may also be used by userspace to 12 * determine that the system supports EFI. 13 */ 14 15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 16 17 #include <linux/kobject.h> 18 #include <linux/module.h> 19 #include <linux/init.h> 20 #include <linux/debugfs.h> 21 #include <linux/device.h> 22 #include <linux/efi.h> 23 #include <linux/of.h> 24 #include <linux/initrd.h> 25 #include <linux/io.h> 26 #include <linux/kexec.h> 27 #include <linux/platform_device.h> 28 #include <linux/random.h> 29 #include <linux/reboot.h> 30 #include <linux/slab.h> 31 #include <linux/acpi.h> 32 #include <linux/ucs2_string.h> 33 #include <linux/memblock.h> 34 #include <linux/security.h> 35 36 #include <asm/early_ioremap.h> 37 38 struct efi __read_mostly efi = { 39 .runtime_supported_mask = EFI_RT_SUPPORTED_ALL, 40 .acpi = EFI_INVALID_TABLE_ADDR, 41 .acpi20 = EFI_INVALID_TABLE_ADDR, 42 .smbios = EFI_INVALID_TABLE_ADDR, 43 .smbios3 = EFI_INVALID_TABLE_ADDR, 44 .esrt = EFI_INVALID_TABLE_ADDR, 45 .tpm_log = EFI_INVALID_TABLE_ADDR, 46 .tpm_final_log = EFI_INVALID_TABLE_ADDR, 47 #ifdef CONFIG_LOAD_UEFI_KEYS 48 .mokvar_table = EFI_INVALID_TABLE_ADDR, 49 #endif 50 #ifdef CONFIG_EFI_COCO_SECRET 51 .coco_secret = EFI_INVALID_TABLE_ADDR, 52 #endif 53 #ifdef CONFIG_UNACCEPTED_MEMORY 54 .unaccepted = EFI_INVALID_TABLE_ADDR, 55 #endif 56 }; 57 EXPORT_SYMBOL(efi); 58 59 unsigned long __ro_after_init efi_rng_seed = EFI_INVALID_TABLE_ADDR; 60 static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR; 61 static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR; 62 static unsigned long __initdata initrd = EFI_INVALID_TABLE_ADDR; 63 64 extern unsigned long screen_info_table; 65 66 struct mm_struct efi_mm = { 67 .mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, efi_mm.mmap_lock), 68 .mm_users = ATOMIC_INIT(2), 69 .mm_count = ATOMIC_INIT(1), 70 .write_protect_seq = SEQCNT_ZERO(efi_mm.write_protect_seq), 71 MMAP_LOCK_INITIALIZER(efi_mm) 72 .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock), 73 .mmlist = LIST_HEAD_INIT(efi_mm.mmlist), 74 .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0}, 75 }; 76 77 struct workqueue_struct *efi_rts_wq; 78 79 static bool disable_runtime = IS_ENABLED(CONFIG_EFI_DISABLE_RUNTIME); 80 static int __init setup_noefi(char *arg) 81 { 82 disable_runtime = true; 83 return 0; 84 } 85 early_param("noefi", setup_noefi); 86 87 bool efi_runtime_disabled(void) 88 { 89 return disable_runtime; 90 } 91 92 bool __pure __efi_soft_reserve_enabled(void) 93 { 94 return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE); 95 } 96 97 static int __init parse_efi_cmdline(char *str) 98 { 99 if (!str) { 100 pr_warn("need at least one option\n"); 101 return -EINVAL; 102 } 103 104 if (parse_option_str(str, "debug")) 105 set_bit(EFI_DBG, &efi.flags); 106 107 if (parse_option_str(str, "noruntime")) 108 disable_runtime = true; 109 110 if (parse_option_str(str, "runtime")) 111 disable_runtime = false; 112 113 if (parse_option_str(str, "nosoftreserve")) 114 set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags); 115 116 return 0; 117 } 118 early_param("efi", parse_efi_cmdline); 119 120 struct kobject *efi_kobj; 121 122 /* 123 * Let's not leave out systab information that snuck into 124 * the efivars driver 125 * Note, do not add more fields in systab sysfs file as it breaks sysfs 126 * one value per file rule! 127 */ 128 static ssize_t systab_show(struct kobject *kobj, 129 struct kobj_attribute *attr, char *buf) 130 { 131 char *str = buf; 132 133 if (!kobj || !buf) 134 return -EINVAL; 135 136 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR) 137 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20); 138 if (efi.acpi != EFI_INVALID_TABLE_ADDR) 139 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi); 140 /* 141 * If both SMBIOS and SMBIOS3 entry points are implemented, the 142 * SMBIOS3 entry point shall be preferred, so we list it first to 143 * let applications stop parsing after the first match. 144 */ 145 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR) 146 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3); 147 if (efi.smbios != EFI_INVALID_TABLE_ADDR) 148 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios); 149 150 if (IS_ENABLED(CONFIG_IA64) || IS_ENABLED(CONFIG_X86)) 151 str = efi_systab_show_arch(str); 152 153 return str - buf; 154 } 155 156 static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400); 157 158 static ssize_t fw_platform_size_show(struct kobject *kobj, 159 struct kobj_attribute *attr, char *buf) 160 { 161 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32); 162 } 163 164 extern __weak struct kobj_attribute efi_attr_fw_vendor; 165 extern __weak struct kobj_attribute efi_attr_runtime; 166 extern __weak struct kobj_attribute efi_attr_config_table; 167 static struct kobj_attribute efi_attr_fw_platform_size = 168 __ATTR_RO(fw_platform_size); 169 170 static struct attribute *efi_subsys_attrs[] = { 171 &efi_attr_systab.attr, 172 &efi_attr_fw_platform_size.attr, 173 &efi_attr_fw_vendor.attr, 174 &efi_attr_runtime.attr, 175 &efi_attr_config_table.attr, 176 NULL, 177 }; 178 179 umode_t __weak efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, 180 int n) 181 { 182 return attr->mode; 183 } 184 185 static const struct attribute_group efi_subsys_attr_group = { 186 .attrs = efi_subsys_attrs, 187 .is_visible = efi_attr_is_visible, 188 }; 189 190 static struct efivars generic_efivars; 191 static struct efivar_operations generic_ops; 192 193 static bool generic_ops_supported(void) 194 { 195 unsigned long name_size; 196 efi_status_t status; 197 efi_char16_t name; 198 efi_guid_t guid; 199 200 name_size = sizeof(name); 201 202 if (!efi.get_next_variable) 203 return false; 204 status = efi.get_next_variable(&name_size, &name, &guid); 205 if (status == EFI_UNSUPPORTED) 206 return false; 207 208 return true; 209 } 210 211 static int generic_ops_register(void) 212 { 213 if (!generic_ops_supported()) 214 return 0; 215 216 generic_ops.get_variable = efi.get_variable; 217 generic_ops.get_next_variable = efi.get_next_variable; 218 generic_ops.query_variable_store = efi_query_variable_store; 219 generic_ops.query_variable_info = efi.query_variable_info; 220 221 if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) { 222 generic_ops.set_variable = efi.set_variable; 223 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking; 224 } 225 return efivars_register(&generic_efivars, &generic_ops); 226 } 227 228 static void generic_ops_unregister(void) 229 { 230 if (!generic_ops.get_variable) 231 return; 232 233 efivars_unregister(&generic_efivars); 234 } 235 236 #ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS 237 #define EFIVAR_SSDT_NAME_MAX 16UL 238 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata; 239 static int __init efivar_ssdt_setup(char *str) 240 { 241 int ret = security_locked_down(LOCKDOWN_ACPI_TABLES); 242 243 if (ret) 244 return ret; 245 246 if (strlen(str) < sizeof(efivar_ssdt)) 247 memcpy(efivar_ssdt, str, strlen(str)); 248 else 249 pr_warn("efivar_ssdt: name too long: %s\n", str); 250 return 1; 251 } 252 __setup("efivar_ssdt=", efivar_ssdt_setup); 253 254 static __init int efivar_ssdt_load(void) 255 { 256 unsigned long name_size = 256; 257 efi_char16_t *name = NULL; 258 efi_status_t status; 259 efi_guid_t guid; 260 261 if (!efivar_ssdt[0]) 262 return 0; 263 264 name = kzalloc(name_size, GFP_KERNEL); 265 if (!name) 266 return -ENOMEM; 267 268 for (;;) { 269 char utf8_name[EFIVAR_SSDT_NAME_MAX]; 270 unsigned long data_size = 0; 271 void *data; 272 int limit; 273 274 status = efi.get_next_variable(&name_size, name, &guid); 275 if (status == EFI_NOT_FOUND) { 276 break; 277 } else if (status == EFI_BUFFER_TOO_SMALL) { 278 efi_char16_t *name_tmp = 279 krealloc(name, name_size, GFP_KERNEL); 280 if (!name_tmp) { 281 kfree(name); 282 return -ENOMEM; 283 } 284 name = name_tmp; 285 continue; 286 } 287 288 limit = min(EFIVAR_SSDT_NAME_MAX, name_size); 289 ucs2_as_utf8(utf8_name, name, limit - 1); 290 if (strncmp(utf8_name, efivar_ssdt, limit) != 0) 291 continue; 292 293 pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt, &guid); 294 295 status = efi.get_variable(name, &guid, NULL, &data_size, NULL); 296 if (status != EFI_BUFFER_TOO_SMALL || !data_size) 297 return -EIO; 298 299 data = kmalloc(data_size, GFP_KERNEL); 300 if (!data) 301 return -ENOMEM; 302 303 status = efi.get_variable(name, &guid, NULL, &data_size, data); 304 if (status == EFI_SUCCESS) { 305 acpi_status ret = acpi_load_table(data, NULL); 306 if (ret) 307 pr_err("failed to load table: %u\n", ret); 308 else 309 continue; 310 } else { 311 pr_err("failed to get var data: 0x%lx\n", status); 312 } 313 kfree(data); 314 } 315 return 0; 316 } 317 #else 318 static inline int efivar_ssdt_load(void) { return 0; } 319 #endif 320 321 #ifdef CONFIG_DEBUG_FS 322 323 #define EFI_DEBUGFS_MAX_BLOBS 32 324 325 static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS]; 326 327 static void __init efi_debugfs_init(void) 328 { 329 struct dentry *efi_debugfs; 330 efi_memory_desc_t *md; 331 char name[32]; 332 int type_count[EFI_BOOT_SERVICES_DATA + 1] = {}; 333 int i = 0; 334 335 efi_debugfs = debugfs_create_dir("efi", NULL); 336 if (IS_ERR_OR_NULL(efi_debugfs)) 337 return; 338 339 for_each_efi_memory_desc(md) { 340 switch (md->type) { 341 case EFI_BOOT_SERVICES_CODE: 342 snprintf(name, sizeof(name), "boot_services_code%d", 343 type_count[md->type]++); 344 break; 345 case EFI_BOOT_SERVICES_DATA: 346 snprintf(name, sizeof(name), "boot_services_data%d", 347 type_count[md->type]++); 348 break; 349 default: 350 continue; 351 } 352 353 if (i >= EFI_DEBUGFS_MAX_BLOBS) { 354 pr_warn("More then %d EFI boot service segments, only showing first %d in debugfs\n", 355 EFI_DEBUGFS_MAX_BLOBS, EFI_DEBUGFS_MAX_BLOBS); 356 break; 357 } 358 359 debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT; 360 debugfs_blob[i].data = memremap(md->phys_addr, 361 debugfs_blob[i].size, 362 MEMREMAP_WB); 363 if (!debugfs_blob[i].data) 364 continue; 365 366 debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]); 367 i++; 368 } 369 } 370 #else 371 static inline void efi_debugfs_init(void) {} 372 #endif 373 374 /* 375 * We register the efi subsystem with the firmware subsystem and the 376 * efivars subsystem with the efi subsystem, if the system was booted with 377 * EFI. 378 */ 379 static int __init efisubsys_init(void) 380 { 381 int error; 382 383 if (!efi_enabled(EFI_RUNTIME_SERVICES)) 384 efi.runtime_supported_mask = 0; 385 386 if (!efi_enabled(EFI_BOOT)) 387 return 0; 388 389 if (efi.runtime_supported_mask) { 390 /* 391 * Since we process only one efi_runtime_service() at a time, an 392 * ordered workqueue (which creates only one execution context) 393 * should suffice for all our needs. 394 */ 395 efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0); 396 if (!efi_rts_wq) { 397 pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n"); 398 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 399 efi.runtime_supported_mask = 0; 400 return 0; 401 } 402 } 403 404 if (efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES)) 405 platform_device_register_simple("rtc-efi", 0, NULL, 0); 406 407 /* We register the efi directory at /sys/firmware/efi */ 408 efi_kobj = kobject_create_and_add("efi", firmware_kobj); 409 if (!efi_kobj) { 410 pr_err("efi: Firmware registration failed.\n"); 411 error = -ENOMEM; 412 goto err_destroy_wq; 413 } 414 415 if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE | 416 EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) { 417 error = generic_ops_register(); 418 if (error) 419 goto err_put; 420 efivar_ssdt_load(); 421 platform_device_register_simple("efivars", 0, NULL, 0); 422 } 423 424 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group); 425 if (error) { 426 pr_err("efi: Sysfs attribute export failed with error %d.\n", 427 error); 428 goto err_unregister; 429 } 430 431 /* and the standard mountpoint for efivarfs */ 432 error = sysfs_create_mount_point(efi_kobj, "efivars"); 433 if (error) { 434 pr_err("efivars: Subsystem registration failed.\n"); 435 goto err_remove_group; 436 } 437 438 if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS)) 439 efi_debugfs_init(); 440 441 #ifdef CONFIG_EFI_COCO_SECRET 442 if (efi.coco_secret != EFI_INVALID_TABLE_ADDR) 443 platform_device_register_simple("efi_secret", 0, NULL, 0); 444 #endif 445 446 return 0; 447 448 err_remove_group: 449 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group); 450 err_unregister: 451 if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE | 452 EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) 453 generic_ops_unregister(); 454 err_put: 455 kobject_put(efi_kobj); 456 efi_kobj = NULL; 457 err_destroy_wq: 458 if (efi_rts_wq) 459 destroy_workqueue(efi_rts_wq); 460 461 return error; 462 } 463 464 subsys_initcall(efisubsys_init); 465 466 void __init efi_find_mirror(void) 467 { 468 efi_memory_desc_t *md; 469 u64 mirror_size = 0, total_size = 0; 470 471 if (!efi_enabled(EFI_MEMMAP)) 472 return; 473 474 for_each_efi_memory_desc(md) { 475 unsigned long long start = md->phys_addr; 476 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; 477 478 total_size += size; 479 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) { 480 memblock_mark_mirror(start, size); 481 mirror_size += size; 482 } 483 } 484 if (mirror_size) 485 pr_info("Memory: %lldM/%lldM mirrored memory\n", 486 mirror_size>>20, total_size>>20); 487 } 488 489 /* 490 * Find the efi memory descriptor for a given physical address. Given a 491 * physical address, determine if it exists within an EFI Memory Map entry, 492 * and if so, populate the supplied memory descriptor with the appropriate 493 * data. 494 */ 495 int __efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md) 496 { 497 efi_memory_desc_t *md; 498 499 if (!efi_enabled(EFI_MEMMAP)) { 500 pr_err_once("EFI_MEMMAP is not enabled.\n"); 501 return -EINVAL; 502 } 503 504 if (!out_md) { 505 pr_err_once("out_md is null.\n"); 506 return -EINVAL; 507 } 508 509 for_each_efi_memory_desc(md) { 510 u64 size; 511 u64 end; 512 513 /* skip bogus entries (including empty ones) */ 514 if ((md->phys_addr & (EFI_PAGE_SIZE - 1)) || 515 (md->num_pages <= 0) || 516 (md->num_pages > (U64_MAX - md->phys_addr) >> EFI_PAGE_SHIFT)) 517 continue; 518 519 size = md->num_pages << EFI_PAGE_SHIFT; 520 end = md->phys_addr + size; 521 if (phys_addr >= md->phys_addr && phys_addr < end) { 522 memcpy(out_md, md, sizeof(*out_md)); 523 return 0; 524 } 525 } 526 return -ENOENT; 527 } 528 529 extern int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md) 530 __weak __alias(__efi_mem_desc_lookup); 531 532 /* 533 * Calculate the highest address of an efi memory descriptor. 534 */ 535 u64 __init efi_mem_desc_end(efi_memory_desc_t *md) 536 { 537 u64 size = md->num_pages << EFI_PAGE_SHIFT; 538 u64 end = md->phys_addr + size; 539 return end; 540 } 541 542 void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {} 543 544 /** 545 * efi_mem_reserve - Reserve an EFI memory region 546 * @addr: Physical address to reserve 547 * @size: Size of reservation 548 * 549 * Mark a region as reserved from general kernel allocation and 550 * prevent it being released by efi_free_boot_services(). 551 * 552 * This function should be called drivers once they've parsed EFI 553 * configuration tables to figure out where their data lives, e.g. 554 * efi_esrt_init(). 555 */ 556 void __init efi_mem_reserve(phys_addr_t addr, u64 size) 557 { 558 /* efi_mem_reserve() does not work under Xen */ 559 if (WARN_ON_ONCE(efi_enabled(EFI_PARAVIRT))) 560 return; 561 562 if (!memblock_is_region_reserved(addr, size)) 563 memblock_reserve(addr, size); 564 565 /* 566 * Some architectures (x86) reserve all boot services ranges 567 * until efi_free_boot_services() because of buggy firmware 568 * implementations. This means the above memblock_reserve() is 569 * superfluous on x86 and instead what it needs to do is 570 * ensure the @start, @size is not freed. 571 */ 572 efi_arch_mem_reserve(addr, size); 573 } 574 575 static const efi_config_table_type_t common_tables[] __initconst = { 576 {ACPI_20_TABLE_GUID, &efi.acpi20, "ACPI 2.0" }, 577 {ACPI_TABLE_GUID, &efi.acpi, "ACPI" }, 578 {SMBIOS_TABLE_GUID, &efi.smbios, "SMBIOS" }, 579 {SMBIOS3_TABLE_GUID, &efi.smbios3, "SMBIOS 3.0" }, 580 {EFI_SYSTEM_RESOURCE_TABLE_GUID, &efi.esrt, "ESRT" }, 581 {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, &efi_mem_attr_table, "MEMATTR" }, 582 {LINUX_EFI_RANDOM_SEED_TABLE_GUID, &efi_rng_seed, "RNG" }, 583 {LINUX_EFI_TPM_EVENT_LOG_GUID, &efi.tpm_log, "TPMEventLog" }, 584 {LINUX_EFI_TPM_FINAL_LOG_GUID, &efi.tpm_final_log, "TPMFinalLog" }, 585 {LINUX_EFI_MEMRESERVE_TABLE_GUID, &mem_reserve, "MEMRESERVE" }, 586 {LINUX_EFI_INITRD_MEDIA_GUID, &initrd, "INITRD" }, 587 {EFI_RT_PROPERTIES_TABLE_GUID, &rt_prop, "RTPROP" }, 588 #ifdef CONFIG_EFI_RCI2_TABLE 589 {DELLEMC_EFI_RCI2_TABLE_GUID, &rci2_table_phys }, 590 #endif 591 #ifdef CONFIG_LOAD_UEFI_KEYS 592 {LINUX_EFI_MOK_VARIABLE_TABLE_GUID, &efi.mokvar_table, "MOKvar" }, 593 #endif 594 #ifdef CONFIG_EFI_COCO_SECRET 595 {LINUX_EFI_COCO_SECRET_AREA_GUID, &efi.coco_secret, "CocoSecret" }, 596 #endif 597 #ifdef CONFIG_UNACCEPTED_MEMORY 598 {LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID, &efi.unaccepted, "Unaccepted" }, 599 #endif 600 #ifdef CONFIG_EFI_GENERIC_STUB 601 {LINUX_EFI_SCREEN_INFO_TABLE_GUID, &screen_info_table }, 602 #endif 603 {}, 604 }; 605 606 static __init int match_config_table(const efi_guid_t *guid, 607 unsigned long table, 608 const efi_config_table_type_t *table_types) 609 { 610 int i; 611 612 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) { 613 if (efi_guidcmp(*guid, table_types[i].guid)) 614 continue; 615 616 if (!efi_config_table_is_usable(guid, table)) { 617 if (table_types[i].name[0]) 618 pr_cont("(%s=0x%lx unusable) ", 619 table_types[i].name, table); 620 return 1; 621 } 622 623 *(table_types[i].ptr) = table; 624 if (table_types[i].name[0]) 625 pr_cont("%s=0x%lx ", table_types[i].name, table); 626 return 1; 627 } 628 629 return 0; 630 } 631 632 /** 633 * reserve_unaccepted - Map and reserve unaccepted configuration table 634 * @unaccepted: Pointer to unaccepted memory table 635 * 636 * memblock_add() makes sure that the table is mapped in direct mapping. During 637 * normal boot it happens automatically because the table is allocated from 638 * usable memory. But during crashkernel boot only memory specifically reserved 639 * for crash scenario is mapped. memblock_add() forces the table to be mapped 640 * in crashkernel case. 641 * 642 * Align the range to the nearest page borders. Ranges smaller than page size 643 * are not going to be mapped. 644 * 645 * memblock_reserve() makes sure that future allocations will not touch the 646 * table. 647 */ 648 649 static __init void reserve_unaccepted(struct efi_unaccepted_memory *unaccepted) 650 { 651 phys_addr_t start, size; 652 653 start = PAGE_ALIGN_DOWN(efi.unaccepted); 654 size = PAGE_ALIGN(sizeof(*unaccepted) + unaccepted->size); 655 656 memblock_add(start, size); 657 memblock_reserve(start, size); 658 } 659 660 int __init efi_config_parse_tables(const efi_config_table_t *config_tables, 661 int count, 662 const efi_config_table_type_t *arch_tables) 663 { 664 const efi_config_table_64_t *tbl64 = (void *)config_tables; 665 const efi_config_table_32_t *tbl32 = (void *)config_tables; 666 const efi_guid_t *guid; 667 unsigned long table; 668 int i; 669 670 pr_info(""); 671 for (i = 0; i < count; i++) { 672 if (!IS_ENABLED(CONFIG_X86)) { 673 guid = &config_tables[i].guid; 674 table = (unsigned long)config_tables[i].table; 675 } else if (efi_enabled(EFI_64BIT)) { 676 guid = &tbl64[i].guid; 677 table = tbl64[i].table; 678 679 if (IS_ENABLED(CONFIG_X86_32) && 680 tbl64[i].table > U32_MAX) { 681 pr_cont("\n"); 682 pr_err("Table located above 4GB, disabling EFI.\n"); 683 return -EINVAL; 684 } 685 } else { 686 guid = &tbl32[i].guid; 687 table = tbl32[i].table; 688 } 689 690 if (!match_config_table(guid, table, common_tables) && arch_tables) 691 match_config_table(guid, table, arch_tables); 692 } 693 pr_cont("\n"); 694 set_bit(EFI_CONFIG_TABLES, &efi.flags); 695 696 if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) { 697 struct linux_efi_random_seed *seed; 698 u32 size = 0; 699 700 seed = early_memremap(efi_rng_seed, sizeof(*seed)); 701 if (seed != NULL) { 702 size = min_t(u32, seed->size, SZ_1K); // sanity check 703 early_memunmap(seed, sizeof(*seed)); 704 } else { 705 pr_err("Could not map UEFI random seed!\n"); 706 } 707 if (size > 0) { 708 seed = early_memremap(efi_rng_seed, 709 sizeof(*seed) + size); 710 if (seed != NULL) { 711 add_bootloader_randomness(seed->bits, size); 712 memzero_explicit(seed->bits, size); 713 early_memunmap(seed, sizeof(*seed) + size); 714 } else { 715 pr_err("Could not map UEFI random seed!\n"); 716 } 717 } 718 } 719 720 if (!IS_ENABLED(CONFIG_X86_32) && efi_enabled(EFI_MEMMAP)) 721 efi_memattr_init(); 722 723 efi_tpm_eventlog_init(); 724 725 if (mem_reserve != EFI_INVALID_TABLE_ADDR) { 726 unsigned long prsv = mem_reserve; 727 728 while (prsv) { 729 struct linux_efi_memreserve *rsv; 730 u8 *p; 731 732 /* 733 * Just map a full page: that is what we will get 734 * anyway, and it permits us to map the entire entry 735 * before knowing its size. 736 */ 737 p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE), 738 PAGE_SIZE); 739 if (p == NULL) { 740 pr_err("Could not map UEFI memreserve entry!\n"); 741 return -ENOMEM; 742 } 743 744 rsv = (void *)(p + prsv % PAGE_SIZE); 745 746 /* reserve the entry itself */ 747 memblock_reserve(prsv, 748 struct_size(rsv, entry, rsv->size)); 749 750 for (i = 0; i < atomic_read(&rsv->count); i++) { 751 memblock_reserve(rsv->entry[i].base, 752 rsv->entry[i].size); 753 } 754 755 prsv = rsv->next; 756 early_memunmap(p, PAGE_SIZE); 757 } 758 } 759 760 if (rt_prop != EFI_INVALID_TABLE_ADDR) { 761 efi_rt_properties_table_t *tbl; 762 763 tbl = early_memremap(rt_prop, sizeof(*tbl)); 764 if (tbl) { 765 efi.runtime_supported_mask &= tbl->runtime_services_supported; 766 early_memunmap(tbl, sizeof(*tbl)); 767 } 768 } 769 770 if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && 771 initrd != EFI_INVALID_TABLE_ADDR && phys_initrd_size == 0) { 772 struct linux_efi_initrd *tbl; 773 774 tbl = early_memremap(initrd, sizeof(*tbl)); 775 if (tbl) { 776 phys_initrd_start = tbl->base; 777 phys_initrd_size = tbl->size; 778 early_memunmap(tbl, sizeof(*tbl)); 779 } 780 } 781 782 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && 783 efi.unaccepted != EFI_INVALID_TABLE_ADDR) { 784 struct efi_unaccepted_memory *unaccepted; 785 786 unaccepted = early_memremap(efi.unaccepted, sizeof(*unaccepted)); 787 if (unaccepted) { 788 789 if (unaccepted->version == 1) { 790 reserve_unaccepted(unaccepted); 791 } else { 792 efi.unaccepted = EFI_INVALID_TABLE_ADDR; 793 } 794 795 early_memunmap(unaccepted, sizeof(*unaccepted)); 796 } 797 } 798 799 return 0; 800 } 801 802 int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr) 803 { 804 if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) { 805 pr_err("System table signature incorrect!\n"); 806 return -EINVAL; 807 } 808 809 return 0; 810 } 811 812 #ifndef CONFIG_IA64 813 static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor, 814 size_t size) 815 { 816 const efi_char16_t *ret; 817 818 ret = early_memremap_ro(fw_vendor, size); 819 if (!ret) 820 pr_err("Could not map the firmware vendor!\n"); 821 return ret; 822 } 823 824 static void __init unmap_fw_vendor(const void *fw_vendor, size_t size) 825 { 826 early_memunmap((void *)fw_vendor, size); 827 } 828 #else 829 #define map_fw_vendor(p, s) __va(p) 830 #define unmap_fw_vendor(v, s) 831 #endif 832 833 void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr, 834 unsigned long fw_vendor) 835 { 836 char vendor[100] = "unknown"; 837 const efi_char16_t *c16; 838 size_t i; 839 u16 rev; 840 841 c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t)); 842 if (c16) { 843 for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i) 844 vendor[i] = c16[i]; 845 vendor[i] = '\0'; 846 847 unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t)); 848 } 849 850 rev = (u16)systab_hdr->revision; 851 pr_info("EFI v%u.%u", systab_hdr->revision >> 16, rev / 10); 852 853 rev %= 10; 854 if (rev) 855 pr_cont(".%u", rev); 856 857 pr_cont(" by %s\n", vendor); 858 859 if (IS_ENABLED(CONFIG_X86_64) && 860 systab_hdr->revision > EFI_1_10_SYSTEM_TABLE_REVISION && 861 !strcmp(vendor, "Apple")) { 862 pr_info("Apple Mac detected, using EFI v1.10 runtime services only\n"); 863 efi.runtime_version = EFI_1_10_SYSTEM_TABLE_REVISION; 864 } 865 } 866 867 static __initdata char memory_type_name[][13] = { 868 "Reserved", 869 "Loader Code", 870 "Loader Data", 871 "Boot Code", 872 "Boot Data", 873 "Runtime Code", 874 "Runtime Data", 875 "Conventional", 876 "Unusable", 877 "ACPI Reclaim", 878 "ACPI Mem NVS", 879 "MMIO", 880 "MMIO Port", 881 "PAL Code", 882 "Persistent", 883 "Unaccepted", 884 }; 885 886 char * __init efi_md_typeattr_format(char *buf, size_t size, 887 const efi_memory_desc_t *md) 888 { 889 char *pos; 890 int type_len; 891 u64 attr; 892 893 pos = buf; 894 if (md->type >= ARRAY_SIZE(memory_type_name)) 895 type_len = snprintf(pos, size, "[type=%u", md->type); 896 else 897 type_len = snprintf(pos, size, "[%-*s", 898 (int)(sizeof(memory_type_name[0]) - 1), 899 memory_type_name[md->type]); 900 if (type_len >= size) 901 return buf; 902 903 pos += type_len; 904 size -= type_len; 905 906 attr = md->attribute; 907 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT | 908 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO | 909 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP | 910 EFI_MEMORY_NV | EFI_MEMORY_SP | EFI_MEMORY_CPU_CRYPTO | 911 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE)) 912 snprintf(pos, size, "|attr=0x%016llx]", 913 (unsigned long long)attr); 914 else 915 snprintf(pos, size, 916 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]", 917 attr & EFI_MEMORY_RUNTIME ? "RUN" : "", 918 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "", 919 attr & EFI_MEMORY_CPU_CRYPTO ? "CC" : "", 920 attr & EFI_MEMORY_SP ? "SP" : "", 921 attr & EFI_MEMORY_NV ? "NV" : "", 922 attr & EFI_MEMORY_XP ? "XP" : "", 923 attr & EFI_MEMORY_RP ? "RP" : "", 924 attr & EFI_MEMORY_WP ? "WP" : "", 925 attr & EFI_MEMORY_RO ? "RO" : "", 926 attr & EFI_MEMORY_UCE ? "UCE" : "", 927 attr & EFI_MEMORY_WB ? "WB" : "", 928 attr & EFI_MEMORY_WT ? "WT" : "", 929 attr & EFI_MEMORY_WC ? "WC" : "", 930 attr & EFI_MEMORY_UC ? "UC" : ""); 931 return buf; 932 } 933 934 /* 935 * IA64 has a funky EFI memory map that doesn't work the same way as 936 * other architectures. 937 */ 938 #ifndef CONFIG_IA64 939 /* 940 * efi_mem_attributes - lookup memmap attributes for physical address 941 * @phys_addr: the physical address to lookup 942 * 943 * Search in the EFI memory map for the region covering 944 * @phys_addr. Returns the EFI memory attributes if the region 945 * was found in the memory map, 0 otherwise. 946 */ 947 u64 efi_mem_attributes(unsigned long phys_addr) 948 { 949 efi_memory_desc_t *md; 950 951 if (!efi_enabled(EFI_MEMMAP)) 952 return 0; 953 954 for_each_efi_memory_desc(md) { 955 if ((md->phys_addr <= phys_addr) && 956 (phys_addr < (md->phys_addr + 957 (md->num_pages << EFI_PAGE_SHIFT)))) 958 return md->attribute; 959 } 960 return 0; 961 } 962 963 /* 964 * efi_mem_type - lookup memmap type for physical address 965 * @phys_addr: the physical address to lookup 966 * 967 * Search in the EFI memory map for the region covering @phys_addr. 968 * Returns the EFI memory type if the region was found in the memory 969 * map, -EINVAL otherwise. 970 */ 971 int efi_mem_type(unsigned long phys_addr) 972 { 973 const efi_memory_desc_t *md; 974 975 if (!efi_enabled(EFI_MEMMAP)) 976 return -ENOTSUPP; 977 978 for_each_efi_memory_desc(md) { 979 if ((md->phys_addr <= phys_addr) && 980 (phys_addr < (md->phys_addr + 981 (md->num_pages << EFI_PAGE_SHIFT)))) 982 return md->type; 983 } 984 return -EINVAL; 985 } 986 #endif 987 988 int efi_status_to_err(efi_status_t status) 989 { 990 int err; 991 992 switch (status) { 993 case EFI_SUCCESS: 994 err = 0; 995 break; 996 case EFI_INVALID_PARAMETER: 997 err = -EINVAL; 998 break; 999 case EFI_OUT_OF_RESOURCES: 1000 err = -ENOSPC; 1001 break; 1002 case EFI_DEVICE_ERROR: 1003 err = -EIO; 1004 break; 1005 case EFI_WRITE_PROTECTED: 1006 err = -EROFS; 1007 break; 1008 case EFI_SECURITY_VIOLATION: 1009 err = -EACCES; 1010 break; 1011 case EFI_NOT_FOUND: 1012 err = -ENOENT; 1013 break; 1014 case EFI_ABORTED: 1015 err = -EINTR; 1016 break; 1017 default: 1018 err = -EINVAL; 1019 } 1020 1021 return err; 1022 } 1023 EXPORT_SYMBOL_GPL(efi_status_to_err); 1024 1025 static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock); 1026 static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init; 1027 1028 static int __init efi_memreserve_map_root(void) 1029 { 1030 if (mem_reserve == EFI_INVALID_TABLE_ADDR) 1031 return -ENODEV; 1032 1033 efi_memreserve_root = memremap(mem_reserve, 1034 sizeof(*efi_memreserve_root), 1035 MEMREMAP_WB); 1036 if (WARN_ON_ONCE(!efi_memreserve_root)) 1037 return -ENOMEM; 1038 return 0; 1039 } 1040 1041 static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size) 1042 { 1043 struct resource *res, *parent; 1044 int ret; 1045 1046 res = kzalloc(sizeof(struct resource), GFP_ATOMIC); 1047 if (!res) 1048 return -ENOMEM; 1049 1050 res->name = "reserved"; 1051 res->flags = IORESOURCE_MEM; 1052 res->start = addr; 1053 res->end = addr + size - 1; 1054 1055 /* we expect a conflict with a 'System RAM' region */ 1056 parent = request_resource_conflict(&iomem_resource, res); 1057 ret = parent ? request_resource(parent, res) : 0; 1058 1059 /* 1060 * Given that efi_mem_reserve_iomem() can be called at any 1061 * time, only call memblock_reserve() if the architecture 1062 * keeps the infrastructure around. 1063 */ 1064 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK) && !ret) 1065 memblock_reserve(addr, size); 1066 1067 return ret; 1068 } 1069 1070 int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) 1071 { 1072 struct linux_efi_memreserve *rsv; 1073 unsigned long prsv; 1074 int rc, index; 1075 1076 if (efi_memreserve_root == (void *)ULONG_MAX) 1077 return -ENODEV; 1078 1079 if (!efi_memreserve_root) { 1080 rc = efi_memreserve_map_root(); 1081 if (rc) 1082 return rc; 1083 } 1084 1085 /* first try to find a slot in an existing linked list entry */ 1086 for (prsv = efi_memreserve_root->next; prsv; ) { 1087 rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB); 1088 if (!rsv) 1089 return -ENOMEM; 1090 index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size); 1091 if (index < rsv->size) { 1092 rsv->entry[index].base = addr; 1093 rsv->entry[index].size = size; 1094 1095 memunmap(rsv); 1096 return efi_mem_reserve_iomem(addr, size); 1097 } 1098 prsv = rsv->next; 1099 memunmap(rsv); 1100 } 1101 1102 /* no slot found - allocate a new linked list entry */ 1103 rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC); 1104 if (!rsv) 1105 return -ENOMEM; 1106 1107 rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K); 1108 if (rc) { 1109 free_page((unsigned long)rsv); 1110 return rc; 1111 } 1112 1113 /* 1114 * The memremap() call above assumes that a linux_efi_memreserve entry 1115 * never crosses a page boundary, so let's ensure that this remains true 1116 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by 1117 * using SZ_4K explicitly in the size calculation below. 1118 */ 1119 rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K); 1120 atomic_set(&rsv->count, 1); 1121 rsv->entry[0].base = addr; 1122 rsv->entry[0].size = size; 1123 1124 spin_lock(&efi_mem_reserve_persistent_lock); 1125 rsv->next = efi_memreserve_root->next; 1126 efi_memreserve_root->next = __pa(rsv); 1127 spin_unlock(&efi_mem_reserve_persistent_lock); 1128 1129 return efi_mem_reserve_iomem(addr, size); 1130 } 1131 1132 static int __init efi_memreserve_root_init(void) 1133 { 1134 if (efi_memreserve_root) 1135 return 0; 1136 if (efi_memreserve_map_root()) 1137 efi_memreserve_root = (void *)ULONG_MAX; 1138 return 0; 1139 } 1140 early_initcall(efi_memreserve_root_init); 1141 1142 #ifdef CONFIG_KEXEC 1143 static int update_efi_random_seed(struct notifier_block *nb, 1144 unsigned long code, void *unused) 1145 { 1146 struct linux_efi_random_seed *seed; 1147 u32 size = 0; 1148 1149 if (!kexec_in_progress) 1150 return NOTIFY_DONE; 1151 1152 seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB); 1153 if (seed != NULL) { 1154 size = min(seed->size, EFI_RANDOM_SEED_SIZE); 1155 memunmap(seed); 1156 } else { 1157 pr_err("Could not map UEFI random seed!\n"); 1158 } 1159 if (size > 0) { 1160 seed = memremap(efi_rng_seed, sizeof(*seed) + size, 1161 MEMREMAP_WB); 1162 if (seed != NULL) { 1163 seed->size = size; 1164 get_random_bytes(seed->bits, seed->size); 1165 memunmap(seed); 1166 } else { 1167 pr_err("Could not map UEFI random seed!\n"); 1168 } 1169 } 1170 return NOTIFY_DONE; 1171 } 1172 1173 static struct notifier_block efi_random_seed_nb = { 1174 .notifier_call = update_efi_random_seed, 1175 }; 1176 1177 static int __init register_update_efi_random_seed(void) 1178 { 1179 if (efi_rng_seed == EFI_INVALID_TABLE_ADDR) 1180 return 0; 1181 return register_reboot_notifier(&efi_random_seed_nb); 1182 } 1183 late_initcall(register_update_efi_random_seed); 1184 #endif 1185