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