drivers/firmware/efi/efi.c

   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
 900         res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
 901         if (!res)
 902                 return -ENOMEM;
 903
 904         res->name       = "reserved";
 905         res->flags      = IORESOURCE_MEM;
 906         res->start      = addr;
 907         res->end        = addr + size - 1;
 908
 909         /* we expect a conflict with a 'System RAM' region */
 910         parent = request_resource_conflict(&iomem_resource, res);
 911         return parent ? request_resource(parent, res) : 0;
 912 }
 913
 914 int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
 915 {
 916         struct linux_efi_memreserve *rsv;
 917         unsigned long prsv;
 918         int rc, index;
 919
 920         if (efi_memreserve_root == (void *)ULONG_MAX)
 921                 return -ENODEV;
 922
 923         if (!efi_memreserve_root) {
 924                 rc = efi_memreserve_map_root();
 925                 if (rc)
 926                         return rc;
 927         }
 928
 929         /* first try to find a slot in an existing linked list entry */
 930         for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
 931                 rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
 932                 index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
 933                 if (index < rsv->size) {
 934                         rsv->entry[index].base = addr;
 935                         rsv->entry[index].size = size;
 936
 937                         memunmap(rsv);
 938                         return efi_mem_reserve_iomem(addr, size);
 939                 }
 940                 memunmap(rsv);
 941         }
 942
 943         /* no slot found - allocate a new linked list entry */
 944         rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
 945         if (!rsv)
 946                 return -ENOMEM;
 947
 948         rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K);
 949         if (rc) {
 950                 free_page((unsigned long)rsv);
 951                 return rc;
 952         }
 953
 954         /*
 955          * The memremap() call above assumes that a linux_efi_memreserve entry
 956          * never crosses a page boundary, so let's ensure that this remains true
 957          * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
 958          * using SZ_4K explicitly in the size calculation below.
 959          */
 960         rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
 961         atomic_set(&rsv->count, 1);
 962         rsv->entry[0].base = addr;
 963         rsv->entry[0].size = size;
 964
 965         spin_lock(&efi_mem_reserve_persistent_lock);
 966         rsv->next = efi_memreserve_root->next;
 967         efi_memreserve_root->next = __pa(rsv);
 968         spin_unlock(&efi_mem_reserve_persistent_lock);
 969
 970         return efi_mem_reserve_iomem(addr, size);
 971 }
 972
 973 static int __init efi_memreserve_root_init(void)
 974 {
 975         if (efi_memreserve_root)
 976                 return 0;
 977         if (efi_memreserve_map_root())
 978                 efi_memreserve_root = (void *)ULONG_MAX;
 979         return 0;
 980 }
 981 early_initcall(efi_memreserve_root_init);
 982
 983 #ifdef CONFIG_KEXEC
 984 static int update_efi_random_seed(struct notifier_block *nb,
 985                                   unsigned long code, void *unused)
 986 {
 987         struct linux_efi_random_seed *seed;
 988         u32 size = 0;
 989
 990         if (!kexec_in_progress)
 991                 return NOTIFY_DONE;
 992
 993         seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB);
 994         if (seed != NULL) {
 995                 size = min(seed->size, EFI_RANDOM_SEED_SIZE);
 996                 memunmap(seed);
 997         } else {
 998                 pr_err("Could not map UEFI random seed!\n");
 999         }
1000         if (size > 0) {
1001                 seed = memremap(efi_rng_seed, sizeof(*seed) + size,
1002                                 MEMREMAP_WB);
1003                 if (seed != NULL) {
1004                         seed->size = size;
1005                         get_random_bytes(seed->bits, seed->size);
1006                         memunmap(seed);
1007                 } else {
1008                         pr_err("Could not map UEFI random seed!\n");
1009                 }
1010         }
1011         return NOTIFY_DONE;
1012 }
1013
1014 static struct notifier_block efi_random_seed_nb = {
1015         .notifier_call = update_efi_random_seed,
1016 };
1017
1018 static int __init register_update_efi_random_seed(void)
1019 {
1020         if (efi_rng_seed == EFI_INVALID_TABLE_ADDR)
1021                 return 0;
1022         return register_reboot_notifier(&efi_random_seed_nb);
1023 }
1024 late_initcall(register_update_efi_random_seed);
1025 #endif