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