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