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                 return -ENOMEM;
 385         }
 386
 387         if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
 388                                       EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) {
 389                 efivar_ssdt_load();
 390                 error = generic_ops_register();
 391                 if (error)
 392                         goto err_put;
 393                 platform_device_register_simple("efivars", 0, NULL, 0);
 394         }
 395
 396         error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
 397         if (error) {
 398                 pr_err("efi: Sysfs attribute export failed with error %d.\n",
 399                        error);
 400                 goto err_unregister;
 401         }
 402
 403         error = efi_runtime_map_init(efi_kobj);
 404         if (error)
 405                 goto err_remove_group;
 406
 407         /* and the standard mountpoint for efivarfs */
 408         error = sysfs_create_mount_point(efi_kobj, "efivars");
 409         if (error) {
 410                 pr_err("efivars: Subsystem registration failed.\n");
 411                 goto err_remove_group;
 412         }
 413
 414         if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
 415                 efi_debugfs_init();
 416
 417         return 0;
 418
 419 err_remove_group:
 420         sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
 421 err_unregister:
 422         if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
 423                                       EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME))
 424                 generic_ops_unregister();
 425 err_put:
 426         kobject_put(efi_kobj);
 427         return error;
 428 }
 429
 430 subsys_initcall(efisubsys_init);
 431
 432 /*
 433  * Find the efi memory descriptor for a given physical address.  Given a
 434  * physical address, determine if it exists within an EFI Memory Map entry,
 435  * and if so, populate the supplied memory descriptor with the appropriate
 436  * data.
 437  */
 438 int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
 439 {
 440         efi_memory_desc_t *md;
 441
 442         if (!efi_enabled(EFI_MEMMAP)) {
 443                 pr_err_once("EFI_MEMMAP is not enabled.\n");
 444                 return -EINVAL;
 445         }
 446
 447         if (!out_md) {
 448                 pr_err_once("out_md is null.\n");
 449                 return -EINVAL;
 450         }
 451
 452         for_each_efi_memory_desc(md) {
 453                 u64 size;
 454                 u64 end;
 455
 456                 size = md->num_pages << EFI_PAGE_SHIFT;
 457                 end = md->phys_addr + size;
 458                 if (phys_addr >= md->phys_addr && phys_addr < end) {
 459                         memcpy(out_md, md, sizeof(*out_md));
 460                         return 0;
 461                 }
 462         }
 463         return -ENOENT;
 464 }
 465
 466 /*
 467  * Calculate the highest address of an efi memory descriptor.
 468  */
 469 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
 470 {
 471         u64 size = md->num_pages << EFI_PAGE_SHIFT;
 472         u64 end = md->phys_addr + size;
 473         return end;
 474 }
 475
 476 void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
 477
 478 /**
 479  * efi_mem_reserve - Reserve an EFI memory region
 480  * @addr: Physical address to reserve
 481  * @size: Size of reservation
 482  *
 483  * Mark a region as reserved from general kernel allocation and
 484  * prevent it being released by efi_free_boot_services().
 485  *
 486  * This function should be called drivers once they've parsed EFI
 487  * configuration tables to figure out where their data lives, e.g.
 488  * efi_esrt_init().
 489  */
 490 void __init efi_mem_reserve(phys_addr_t addr, u64 size)
 491 {
 492         if (!memblock_is_region_reserved(addr, size))
 493                 memblock_reserve(addr, size);
 494
 495         /*
 496          * Some architectures (x86) reserve all boot services ranges
 497          * until efi_free_boot_services() because of buggy firmware
 498          * implementations. This means the above memblock_reserve() is
 499          * superfluous on x86 and instead what it needs to do is
 500          * ensure the @start, @size is not freed.
 501          */
 502         efi_arch_mem_reserve(addr, size);
 503 }
 504
 505 static const efi_config_table_type_t common_tables[] __initconst = {
 506         {ACPI_20_TABLE_GUID,                    &efi.acpi20,            "ACPI 2.0"      },
 507         {ACPI_TABLE_GUID,                       &efi.acpi,              "ACPI"          },
 508         {SMBIOS_TABLE_GUID,                     &efi.smbios,            "SMBIOS"        },
 509         {SMBIOS3_TABLE_GUID,                    &efi.smbios3,           "SMBIOS 3.0"    },
 510         {EFI_SYSTEM_RESOURCE_TABLE_GUID,        &efi.esrt,              "ESRT"          },
 511         {EFI_MEMORY_ATTRIBUTES_TABLE_GUID,      &efi_mem_attr_table,    "MEMATTR"       },
 512         {LINUX_EFI_RANDOM_SEED_TABLE_GUID,      &efi_rng_seed,          "RNG"           },
 513         {LINUX_EFI_TPM_EVENT_LOG_GUID,          &efi.tpm_log,           "TPMEventLog"   },
 514         {LINUX_EFI_TPM_FINAL_LOG_GUID,          &efi.tpm_final_log,     "TPMFinalLog"   },
 515         {LINUX_EFI_MEMRESERVE_TABLE_GUID,       &mem_reserve,           "MEMRESERVE"    },
 516         {EFI_RT_PROPERTIES_TABLE_GUID,          &rt_prop,               "RTPROP"        },
 517 #ifdef CONFIG_EFI_RCI2_TABLE
 518         {DELLEMC_EFI_RCI2_TABLE_GUID,           &rci2_table_phys                        },
 519 #endif
 520         {},
 521 };
 522
 523 static __init int match_config_table(const efi_guid_t *guid,
 524                                      unsigned long table,
 525                                      const efi_config_table_type_t *table_types)
 526 {
 527         int i;
 528
 529         for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
 530                 if (!efi_guidcmp(*guid, table_types[i].guid)) {
 531                         *(table_types[i].ptr) = table;
 532                         if (table_types[i].name[0])
 533                                 pr_cont("%s=0x%lx ",
 534                                         table_types[i].name, table);
 535                         return 1;
 536                 }
 537         }
 538
 539         return 0;
 540 }
 541
 542 int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
 543                                    int count,
 544                                    const efi_config_table_type_t *arch_tables)
 545 {
 546         const efi_config_table_64_t *tbl64 = (void *)config_tables;
 547         const efi_config_table_32_t *tbl32 = (void *)config_tables;
 548         const efi_guid_t *guid;
 549         unsigned long table;
 550         int i;
 551
 552         pr_info("");
 553         for (i = 0; i < count; i++) {
 554                 if (!IS_ENABLED(CONFIG_X86)) {
 555                         guid = &config_tables[i].guid;
 556                         table = (unsigned long)config_tables[i].table;
 557                 } else if (efi_enabled(EFI_64BIT)) {
 558                         guid = &tbl64[i].guid;
 559                         table = tbl64[i].table;
 560
 561                         if (IS_ENABLED(CONFIG_X86_32) &&
 562                             tbl64[i].table > U32_MAX) {
 563                                 pr_cont("\n");
 564                                 pr_err("Table located above 4GB, disabling EFI.\n");
 565                                 return -EINVAL;
 566                         }
 567                 } else {
 568                         guid = &tbl32[i].guid;
 569                         table = tbl32[i].table;
 570                 }
 571
 572                 if (!match_config_table(guid, table, common_tables) && arch_tables)
 573                         match_config_table(guid, table, arch_tables);
 574         }
 575         pr_cont("\n");
 576         set_bit(EFI_CONFIG_TABLES, &efi.flags);
 577
 578         if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) {
 579                 struct linux_efi_random_seed *seed;
 580                 u32 size = 0;
 581
 582                 seed = early_memremap(efi_rng_seed, sizeof(*seed));
 583                 if (seed != NULL) {
 584                         size = READ_ONCE(seed->size);
 585                         early_memunmap(seed, sizeof(*seed));
 586                 } else {
 587                         pr_err("Could not map UEFI random seed!\n");
 588                 }
 589                 if (size > 0) {
 590                         seed = early_memremap(efi_rng_seed,
 591                                               sizeof(*seed) + size);
 592                         if (seed != NULL) {
 593                                 pr_notice("seeding entropy pool\n");
 594                                 add_bootloader_randomness(seed->bits, size);
 595                                 early_memunmap(seed, sizeof(*seed) + size);
 596                         } else {
 597                                 pr_err("Could not map UEFI random seed!\n");
 598                         }
 599                 }
 600         }
 601
 602         if (!IS_ENABLED(CONFIG_X86_32) && efi_enabled(EFI_MEMMAP))
 603                 efi_memattr_init();
 604
 605         efi_tpm_eventlog_init();
 606
 607         if (mem_reserve != EFI_INVALID_TABLE_ADDR) {
 608                 unsigned long prsv = mem_reserve;
 609
 610                 while (prsv) {
 611                         struct linux_efi_memreserve *rsv;
 612                         u8 *p;
 613
 614                         /*
 615                          * Just map a full page: that is what we will get
 616                          * anyway, and it permits us to map the entire entry
 617                          * before knowing its size.
 618                          */
 619                         p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
 620                                            PAGE_SIZE);
 621                         if (p == NULL) {
 622                                 pr_err("Could not map UEFI memreserve entry!\n");
 623                                 return -ENOMEM;
 624                         }
 625
 626                         rsv = (void *)(p + prsv % PAGE_SIZE);
 627
 628                         /* reserve the entry itself */
 629                         memblock_reserve(prsv,
 630                                          struct_size(rsv, entry, rsv->size));
 631
 632                         for (i = 0; i < atomic_read(&rsv->count); i++) {
 633                                 memblock_reserve(rsv->entry[i].base,
 634                                                  rsv->entry[i].size);
 635                         }
 636
 637                         prsv = rsv->next;
 638                         early_memunmap(p, PAGE_SIZE);
 639                 }
 640         }
 641
 642         if (rt_prop != EFI_INVALID_TABLE_ADDR) {
 643                 efi_rt_properties_table_t *tbl;
 644
 645                 tbl = early_memremap(rt_prop, sizeof(*tbl));
 646                 if (tbl) {
 647                         efi.runtime_supported_mask &= tbl->runtime_services_supported;
 648                         early_memunmap(tbl, sizeof(*tbl));
 649                 }
 650         }
 651
 652         return 0;
 653 }
 654
 655 int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr,
 656                                    int min_major_version)
 657 {
 658         if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) {
 659                 pr_err("System table signature incorrect!\n");
 660                 return -EINVAL;
 661         }
 662
 663         if ((systab_hdr->revision >> 16) < min_major_version)
 664                 pr_err("Warning: System table version %d.%02d, expected %d.00 or greater!\n",
 665                        systab_hdr->revision >> 16,
 666                        systab_hdr->revision & 0xffff,
 667                        min_major_version);
 668
 669         return 0;
 670 }
 671
 672 #ifndef CONFIG_IA64
 673 static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor,
 674                                                 size_t size)
 675 {
 676         const efi_char16_t *ret;
 677
 678         ret = early_memremap_ro(fw_vendor, size);
 679         if (!ret)
 680                 pr_err("Could not map the firmware vendor!\n");
 681         return ret;
 682 }
 683
 684 static void __init unmap_fw_vendor(const void *fw_vendor, size_t size)
 685 {
 686         early_memunmap((void *)fw_vendor, size);
 687 }
 688 #else
 689 #define map_fw_vendor(p, s)     __va(p)
 690 #define unmap_fw_vendor(v, s)
 691 #endif
 692
 693 void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
 694                                      unsigned long fw_vendor)
 695 {
 696         char vendor[100] = "unknown";
 697         const efi_char16_t *c16;
 698         size_t i;
 699
 700         c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t));
 701         if (c16) {
 702                 for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
 703                         vendor[i] = c16[i];
 704                 vendor[i] = '\0';
 705
 706                 unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t));
 707         }
 708
 709         pr_info("EFI v%u.%.02u by %s\n",
 710                 systab_hdr->revision >> 16,
 711                 systab_hdr->revision & 0xffff,
 712                 vendor);
 713 }
 714
 715 static __initdata char memory_type_name[][20] = {
 716         "Reserved",
 717         "Loader Code",
 718         "Loader Data",
 719         "Boot Code",
 720         "Boot Data",
 721         "Runtime Code",
 722         "Runtime Data",
 723         "Conventional Memory",
 724         "Unusable Memory",
 725         "ACPI Reclaim Memory",
 726         "ACPI Memory NVS",
 727         "Memory Mapped I/O",
 728         "MMIO Port Space",
 729         "PAL Code",
 730         "Persistent Memory",
 731 };
 732
 733 char * __init efi_md_typeattr_format(char *buf, size_t size,
 734                                      const efi_memory_desc_t *md)
 735 {
 736         char *pos;
 737         int type_len;
 738         u64 attr;
 739
 740         pos = buf;
 741         if (md->type >= ARRAY_SIZE(memory_type_name))
 742                 type_len = snprintf(pos, size, "[type=%u", md->type);
 743         else
 744                 type_len = snprintf(pos, size, "[%-*s",
 745                                     (int)(sizeof(memory_type_name[0]) - 1),
 746                                     memory_type_name[md->type]);
 747         if (type_len >= size)
 748                 return buf;
 749
 750         pos += type_len;
 751         size -= type_len;
 752
 753         attr = md->attribute;
 754         if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
 755                      EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
 756                      EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
 757                      EFI_MEMORY_NV | EFI_MEMORY_SP |
 758                      EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
 759                 snprintf(pos, size, "|attr=0x%016llx]",
 760                          (unsigned long long)attr);
 761         else
 762                 snprintf(pos, size,
 763                          "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
 764                          attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
 765                          attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
 766                          attr & EFI_MEMORY_SP      ? "SP"  : "",
 767                          attr & EFI_MEMORY_NV      ? "NV"  : "",
 768                          attr & EFI_MEMORY_XP      ? "XP"  : "",
 769                          attr & EFI_MEMORY_RP      ? "RP"  : "",
 770                          attr & EFI_MEMORY_WP      ? "WP"  : "",
 771                          attr & EFI_MEMORY_RO      ? "RO"  : "",
 772                          attr & EFI_MEMORY_UCE     ? "UCE" : "",
 773                          attr & EFI_MEMORY_WB      ? "WB"  : "",
 774                          attr & EFI_MEMORY_WT      ? "WT"  : "",
 775                          attr & EFI_MEMORY_WC      ? "WC"  : "",
 776                          attr & EFI_MEMORY_UC      ? "UC"  : "");
 777         return buf;
 778 }
 779
 780 /*
 781  * IA64 has a funky EFI memory map that doesn't work the same way as
 782  * other architectures.
 783  */
 784 #ifndef CONFIG_IA64
 785 /*
 786  * efi_mem_attributes - lookup memmap attributes for physical address
 787  * @phys_addr: the physical address to lookup
 788  *
 789  * Search in the EFI memory map for the region covering
 790  * @phys_addr. Returns the EFI memory attributes if the region
 791  * was found in the memory map, 0 otherwise.
 792  */
 793 u64 efi_mem_attributes(unsigned long phys_addr)
 794 {
 795         efi_memory_desc_t *md;
 796
 797         if (!efi_enabled(EFI_MEMMAP))
 798                 return 0;
 799
 800         for_each_efi_memory_desc(md) {
 801                 if ((md->phys_addr <= phys_addr) &&
 802                     (phys_addr < (md->phys_addr +
 803                     (md->num_pages << EFI_PAGE_SHIFT))))
 804                         return md->attribute;
 805         }
 806         return 0;
 807 }
 808
 809 /*
 810  * efi_mem_type - lookup memmap type for physical address
 811  * @phys_addr: the physical address to lookup
 812  *
 813  * Search in the EFI memory map for the region covering @phys_addr.
 814  * Returns the EFI memory type if the region was found in the memory
 815  * map, -EINVAL otherwise.
 816  */
 817 int efi_mem_type(unsigned long phys_addr)
 818 {
 819         const efi_memory_desc_t *md;
 820
 821         if (!efi_enabled(EFI_MEMMAP))
 822                 return -ENOTSUPP;
 823
 824         for_each_efi_memory_desc(md) {
 825                 if ((md->phys_addr <= phys_addr) &&
 826                     (phys_addr < (md->phys_addr +
 827                                   (md->num_pages << EFI_PAGE_SHIFT))))
 828                         return md->type;
 829         }
 830         return -EINVAL;
 831 }
 832 #endif
 833
 834 int efi_status_to_err(efi_status_t status)
 835 {
 836         int err;
 837
 838         switch (status) {
 839         case EFI_SUCCESS:
 840                 err = 0;
 841                 break;
 842         case EFI_INVALID_PARAMETER:
 843                 err = -EINVAL;
 844                 break;
 845         case EFI_OUT_OF_RESOURCES:
 846                 err = -ENOSPC;
 847                 break;
 848         case EFI_DEVICE_ERROR:
 849                 err = -EIO;
 850                 break;
 851         case EFI_WRITE_PROTECTED:
 852                 err = -EROFS;
 853                 break;
 854         case EFI_SECURITY_VIOLATION:
 855                 err = -EACCES;
 856                 break;
 857         case EFI_NOT_FOUND:
 858                 err = -ENOENT;
 859                 break;
 860         case EFI_ABORTED:
 861                 err = -EINTR;
 862                 break;
 863         default:
 864                 err = -EINVAL;
 865         }
 866
 867         return err;
 868 }
 869
 870 static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
 871 static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
 872
 873 static int __init efi_memreserve_map_root(void)
 874 {
 875         if (mem_reserve == EFI_INVALID_TABLE_ADDR)
 876                 return -ENODEV;
 877
 878         efi_memreserve_root = memremap(mem_reserve,
 879                                        sizeof(*efi_memreserve_root),
 880                                        MEMREMAP_WB);
 881         if (WARN_ON_ONCE(!efi_memreserve_root))
 882                 return -ENOMEM;
 883         return 0;
 884 }
 885
 886 static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size)
 887 {
 888         struct resource *res, *parent;
 889
 890         res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
 891         if (!res)
 892                 return -ENOMEM;
 893
 894         res->name       = "reserved";
 895         res->flags      = IORESOURCE_MEM;
 896         res->start      = addr;
 897         res->end        = addr + size - 1;
 898
 899         /* we expect a conflict with a 'System RAM' region */
 900         parent = request_resource_conflict(&iomem_resource, res);
 901         return parent ? request_resource(parent, res) : 0;
 902 }
 903
 904 int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
 905 {
 906         struct linux_efi_memreserve *rsv;
 907         unsigned long prsv;
 908         int rc, index;
 909
 910         if (efi_memreserve_root == (void *)ULONG_MAX)
 911                 return -ENODEV;
 912
 913         if (!efi_memreserve_root) {
 914                 rc = efi_memreserve_map_root();
 915                 if (rc)
 916                         return rc;
 917         }
 918
 919         /* first try to find a slot in an existing linked list entry */
 920         for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
 921                 rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
 922                 index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
 923                 if (index < rsv->size) {
 924                         rsv->entry[index].base = addr;
 925                         rsv->entry[index].size = size;
 926
 927                         memunmap(rsv);
 928                         return efi_mem_reserve_iomem(addr, size);
 929                 }
 930                 memunmap(rsv);
 931         }
 932
 933         /* no slot found - allocate a new linked list entry */
 934         rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
 935         if (!rsv)
 936                 return -ENOMEM;
 937
 938         rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K);
 939         if (rc) {
 940                 free_page((unsigned long)rsv);
 941                 return rc;
 942         }
 943
 944         /*
 945          * The memremap() call above assumes that a linux_efi_memreserve entry
 946          * never crosses a page boundary, so let's ensure that this remains true
 947          * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
 948          * using SZ_4K explicitly in the size calculation below.
 949          */
 950         rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
 951         atomic_set(&rsv->count, 1);
 952         rsv->entry[0].base = addr;
 953         rsv->entry[0].size = size;
 954
 955         spin_lock(&efi_mem_reserve_persistent_lock);
 956         rsv->next = efi_memreserve_root->next;
 957         efi_memreserve_root->next = __pa(rsv);
 958         spin_unlock(&efi_mem_reserve_persistent_lock);
 959
 960         return efi_mem_reserve_iomem(addr, size);
 961 }
 962
 963 static int __init efi_memreserve_root_init(void)
 964 {
 965         if (efi_memreserve_root)
 966                 return 0;
 967         if (efi_memreserve_map_root())
 968                 efi_memreserve_root = (void *)ULONG_MAX;
 969         return 0;
 970 }
 971 early_initcall(efi_memreserve_root_init);
 972
 973 #ifdef CONFIG_KEXEC
 974 static int update_efi_random_seed(struct notifier_block *nb,
 975                                   unsigned long code, void *unused)
 976 {
 977         struct linux_efi_random_seed *seed;
 978         u32 size = 0;
 979
 980         if (!kexec_in_progress)
 981                 return NOTIFY_DONE;
 982
 983         seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB);
 984         if (seed != NULL) {
 985                 size = min(seed->size, EFI_RANDOM_SEED_SIZE);
 986                 memunmap(seed);
 987         } else {
 988                 pr_err("Could not map UEFI random seed!\n");
 989         }
 990         if (size > 0) {
 991                 seed = memremap(efi_rng_seed, sizeof(*seed) + size,
 992                                 MEMREMAP_WB);
 993                 if (seed != NULL) {
 994                         seed->size = size;
 995                         get_random_bytes(seed->bits, seed->size);
 996                         memunmap(seed);
 997                 } else {
 998                         pr_err("Could not map UEFI random seed!\n");
 999                 }
1000         }
1001         return NOTIFY_DONE;
1002 }
1003
1004 static struct notifier_block efi_random_seed_nb = {
1005         .notifier_call = update_efi_random_seed,
1006 };
1007
1008 static int __init register_update_efi_random_seed(void)
1009 {
1010         if (efi_rng_seed == EFI_INVALID_TABLE_ADDR)
1011                 return 0;
1012         return register_reboot_notifier(&efi_random_seed_nb);
1013 }
1014 late_initcall(register_update_efi_random_seed);
1015 #endif