arch/x86/platform/efi/efi.c

   1 /*
   2  * Common EFI (Extensible Firmware Interface) support functions
   3  * Based on Extensible Firmware Interface Specification version 1.0
   4  *
   5  * Copyright (C) 1999 VA Linux Systems
   6  * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
   7  * Copyright (C) 1999-2002 Hewlett-Packard Co.
   8  *      David Mosberger-Tang <davidm@hpl.hp.com>
   9  *      Stephane Eranian <eranian@hpl.hp.com>
  10  * Copyright (C) 2005-2008 Intel Co.
  11  *      Fenghua Yu <fenghua.yu@intel.com>
  12  *      Bibo Mao <bibo.mao@intel.com>
  13  *      Chandramouli Narayanan <mouli@linux.intel.com>
  14  *      Huang Ying <ying.huang@intel.com>
  15  * Copyright (C) 2013 SuSE Labs
  16  *      Borislav Petkov <bp@suse.de> - runtime services VA mapping
  17  *
  18  * Copied from efi_32.c to eliminate the duplicated code between EFI
  19  * 32/64 support code. --ying 2007-10-26
  20  *
  21  * All EFI Runtime Services are not implemented yet as EFI only
  22  * supports physical mode addressing on SoftSDV. This is to be fixed
  23  * in a future version.  --drummond 1999-07-20
  24  *
  25  * Implemented EFI runtime services and virtual mode calls.  --davidm
  26  *
  27  * Goutham Rao: <goutham.rao@intel.com>
  28  *      Skip non-WB memory and ignore empty memory ranges.
  29  */
  30
  31 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  32
  33 #include <linux/kernel.h>
  34 #include <linux/init.h>
  35 #include <linux/efi.h>
  36 #include <linux/efi-bgrt.h>
  37 #include <linux/export.h>
  38 #include <linux/bootmem.h>
  39 #include <linux/slab.h>
  40 #include <linux/memblock.h>
  41 #include <linux/spinlock.h>
  42 #include <linux/uaccess.h>
  43 #include <linux/time.h>
  44 #include <linux/io.h>
  45 #include <linux/reboot.h>
  46 #include <linux/bcd.h>
  47
  48 #include <asm/setup.h>
  49 #include <asm/efi.h>
  50 #include <asm/time.h>
  51 #include <asm/cacheflush.h>
  52 #include <asm/tlbflush.h>
  53 #include <asm/x86_init.h>
  54 #include <asm/rtc.h>
  55 #include <asm/uv/uv.h>
  56
  57 #define EFI_DEBUG
  58
  59 #define EFI_MIN_RESERVE 5120
  60
  61 #define EFI_DUMMY_GUID \
  62         EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9)
  63
  64 static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
  65
  66 struct efi_memory_map memmap;
  67
  68 static struct efi efi_phys __initdata;
  69 static efi_system_table_t efi_systab __initdata;
  70
  71 static efi_config_table_type_t arch_tables[] __initdata = {
  72 #ifdef CONFIG_X86_UV
  73         {UV_SYSTEM_TABLE_GUID, "UVsystab", &efi.uv_systab},
  74 #endif
  75         {NULL_GUID, NULL, NULL},
  76 };
  77
  78 u64 efi_setup;          /* efi setup_data physical address */
  79
  80 static bool disable_runtime __initdata = false;
  81 static int __init setup_noefi(char *arg)
  82 {
  83         disable_runtime = true;
  84         return 0;
  85 }
  86 early_param("noefi", setup_noefi);
  87
  88 int add_efi_memmap;
  89 EXPORT_SYMBOL(add_efi_memmap);
  90
  91 static int __init setup_add_efi_memmap(char *arg)
  92 {
  93         add_efi_memmap = 1;
  94         return 0;
  95 }
  96 early_param("add_efi_memmap", setup_add_efi_memmap);
  97
  98 static bool efi_no_storage_paranoia;
  99
 100 static int __init setup_storage_paranoia(char *arg)
 101 {
 102         efi_no_storage_paranoia = true;
 103         return 0;
 104 }
 105 early_param("efi_no_storage_paranoia", setup_storage_paranoia);
 106
 107 static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 108 {
 109         unsigned long flags;
 110         efi_status_t status;
 111
 112         spin_lock_irqsave(&rtc_lock, flags);
 113         status = efi_call_virt2(get_time, tm, tc);
 114         spin_unlock_irqrestore(&rtc_lock, flags);
 115         return status;
 116 }
 117
 118 static efi_status_t virt_efi_set_time(efi_time_t *tm)
 119 {
 120         unsigned long flags;
 121         efi_status_t status;
 122
 123         spin_lock_irqsave(&rtc_lock, flags);
 124         status = efi_call_virt1(set_time, tm);
 125         spin_unlock_irqrestore(&rtc_lock, flags);
 126         return status;
 127 }
 128
 129 static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
 130                                              efi_bool_t *pending,
 131                                              efi_time_t *tm)
 132 {
 133         unsigned long flags;
 134         efi_status_t status;
 135
 136         spin_lock_irqsave(&rtc_lock, flags);
 137         status = efi_call_virt3(get_wakeup_time,
 138                                 enabled, pending, tm);
 139         spin_unlock_irqrestore(&rtc_lock, flags);
 140         return status;
 141 }
 142
 143 static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 144 {
 145         unsigned long flags;
 146         efi_status_t status;
 147
 148         spin_lock_irqsave(&rtc_lock, flags);
 149         status = efi_call_virt2(set_wakeup_time,
 150                                 enabled, tm);
 151         spin_unlock_irqrestore(&rtc_lock, flags);
 152         return status;
 153 }
 154
 155 static efi_status_t virt_efi_get_variable(efi_char16_t *name,
 156                                           efi_guid_t *vendor,
 157                                           u32 *attr,
 158                                           unsigned long *data_size,
 159                                           void *data)
 160 {
 161         return efi_call_virt5(get_variable,
 162                               name, vendor, attr,
 163                               data_size, data);
 164 }
 165
 166 static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
 167                                                efi_char16_t *name,
 168                                                efi_guid_t *vendor)
 169 {
 170         return efi_call_virt3(get_next_variable,
 171                               name_size, name, vendor);
 172 }
 173
 174 static efi_status_t virt_efi_set_variable(efi_char16_t *name,
 175                                           efi_guid_t *vendor,
 176                                           u32 attr,
 177                                           unsigned long data_size,
 178                                           void *data)
 179 {
 180         return efi_call_virt5(set_variable,
 181                               name, vendor, attr,
 182                               data_size, data);
 183 }
 184
 185 static efi_status_t virt_efi_query_variable_info(u32 attr,
 186                                                  u64 *storage_space,
 187                                                  u64 *remaining_space,
 188                                                  u64 *max_variable_size)
 189 {
 190         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 191                 return EFI_UNSUPPORTED;
 192
 193         return efi_call_virt4(query_variable_info, attr, storage_space,
 194                               remaining_space, max_variable_size);
 195 }
 196
 197 static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
 198 {
 199         return efi_call_virt1(get_next_high_mono_count, count);
 200 }
 201
 202 static void virt_efi_reset_system(int reset_type,
 203                                   efi_status_t status,
 204                                   unsigned long data_size,
 205                                   efi_char16_t *data)
 206 {
 207         efi_call_virt4(reset_system, reset_type, status,
 208                        data_size, data);
 209 }
 210
 211 static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
 212                                             unsigned long count,
 213                                             unsigned long sg_list)
 214 {
 215         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 216                 return EFI_UNSUPPORTED;
 217
 218         return efi_call_virt3(update_capsule, capsules, count, sg_list);
 219 }
 220
 221 static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
 222                                                 unsigned long count,
 223                                                 u64 *max_size,
 224                                                 int *reset_type)
 225 {
 226         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 227                 return EFI_UNSUPPORTED;
 228
 229         return efi_call_virt4(query_capsule_caps, capsules, count, max_size,
 230                               reset_type);
 231 }
 232
 233 static efi_status_t __init phys_efi_set_virtual_address_map(
 234         unsigned long memory_map_size,
 235         unsigned long descriptor_size,
 236         u32 descriptor_version,
 237         efi_memory_desc_t *virtual_map)
 238 {
 239         efi_status_t status;
 240
 241         efi_call_phys_prelog();
 242         status = efi_call_phys4(efi_phys.set_virtual_address_map,
 243                                 memory_map_size, descriptor_size,
 244                                 descriptor_version, virtual_map);
 245         efi_call_phys_epilog();
 246         return status;
 247 }
 248
 249 static efi_status_t __init phys_efi_get_time(efi_time_t *tm,
 250                                              efi_time_cap_t *tc)
 251 {
 252         unsigned long flags;
 253         efi_status_t status;
 254
 255         spin_lock_irqsave(&rtc_lock, flags);
 256         efi_call_phys_prelog();
 257         status = efi_call_phys2(efi_phys.get_time, virt_to_phys(tm),
 258                                 virt_to_phys(tc));
 259         efi_call_phys_epilog();
 260         spin_unlock_irqrestore(&rtc_lock, flags);
 261         return status;
 262 }
 263
 264 int efi_set_rtc_mmss(const struct timespec *now)
 265 {
 266         unsigned long nowtime = now->tv_sec;
 267         efi_status_t    status;
 268         efi_time_t      eft;
 269         efi_time_cap_t  cap;
 270         struct rtc_time tm;
 271
 272         status = efi.get_time(&eft, &cap);
 273         if (status != EFI_SUCCESS) {
 274                 pr_err("Oops: efitime: can't read time!\n");
 275                 return -1;
 276         }
 277
 278         rtc_time_to_tm(nowtime, &tm);
 279         if (!rtc_valid_tm(&tm)) {
 280                 eft.year = tm.tm_year + 1900;
 281                 eft.month = tm.tm_mon + 1;
 282                 eft.day = tm.tm_mday;
 283                 eft.minute = tm.tm_min;
 284                 eft.second = tm.tm_sec;
 285                 eft.nanosecond = 0;
 286         } else {
 287                 pr_err("%s: Invalid EFI RTC value: write of %lx to EFI RTC failed\n",
 288                        __func__, nowtime);
 289                 return -1;
 290         }
 291
 292         status = efi.set_time(&eft);
 293         if (status != EFI_SUCCESS) {
 294                 pr_err("Oops: efitime: can't write time!\n");
 295                 return -1;
 296         }
 297         return 0;
 298 }
 299
 300 void efi_get_time(struct timespec *now)
 301 {
 302         efi_status_t status;
 303         efi_time_t eft;
 304         efi_time_cap_t cap;
 305
 306         status = efi.get_time(&eft, &cap);
 307         if (status != EFI_SUCCESS)
 308                 pr_err("Oops: efitime: can't read time!\n");
 309
 310         now->tv_sec = mktime(eft.year, eft.month, eft.day, eft.hour,
 311                              eft.minute, eft.second);
 312         now->tv_nsec = 0;
 313 }
 314
 315 /*
 316  * Tell the kernel about the EFI memory map.  This might include
 317  * more than the max 128 entries that can fit in the e820 legacy
 318  * (zeropage) memory map.
 319  */
 320
 321 static void __init do_add_efi_memmap(void)
 322 {
 323         void *p;
 324
 325         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 326                 efi_memory_desc_t *md = p;
 327                 unsigned long long start = md->phys_addr;
 328                 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
 329                 int e820_type;
 330
 331                 switch (md->type) {
 332                 case EFI_LOADER_CODE:
 333                 case EFI_LOADER_DATA:
 334                 case EFI_BOOT_SERVICES_CODE:
 335                 case EFI_BOOT_SERVICES_DATA:
 336                 case EFI_CONVENTIONAL_MEMORY:
 337                         if (md->attribute & EFI_MEMORY_WB)
 338                                 e820_type = E820_RAM;
 339                         else
 340                                 e820_type = E820_RESERVED;
 341                         break;
 342                 case EFI_ACPI_RECLAIM_MEMORY:
 343                         e820_type = E820_ACPI;
 344                         break;
 345                 case EFI_ACPI_MEMORY_NVS:
 346                         e820_type = E820_NVS;
 347                         break;
 348                 case EFI_UNUSABLE_MEMORY:
 349                         e820_type = E820_UNUSABLE;
 350                         break;
 351                 default:
 352                         /*
 353                          * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
 354                          * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
 355                          * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
 356                          */
 357                         e820_type = E820_RESERVED;
 358                         break;
 359                 }
 360                 e820_add_region(start, size, e820_type);
 361         }
 362         sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 363 }
 364
 365 int __init efi_memblock_x86_reserve_range(void)
 366 {
 367         struct efi_info *e = &boot_params.efi_info;
 368         unsigned long pmap;
 369
 370 #ifdef CONFIG_X86_32
 371         /* Can't handle data above 4GB at this time */
 372         if (e->efi_memmap_hi) {
 373                 pr_err("Memory map is above 4GB, disabling EFI.\n");
 374                 return -EINVAL;
 375         }
 376         pmap =  e->efi_memmap;
 377 #else
 378         pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));
 379 #endif
 380         memmap.phys_map         = (void *)pmap;
 381         memmap.nr_map           = e->efi_memmap_size /
 382                                   e->efi_memdesc_size;
 383         memmap.desc_size        = e->efi_memdesc_size;
 384         memmap.desc_version     = e->efi_memdesc_version;
 385
 386         memblock_reserve(pmap, memmap.nr_map * memmap.desc_size);
 387
 388         efi.memmap = &memmap;
 389
 390         return 0;
 391 }
 392
 393 static void __init print_efi_memmap(void)
 394 {
 395 #ifdef EFI_DEBUG
 396         efi_memory_desc_t *md;
 397         void *p;
 398         int i;
 399
 400         for (p = memmap.map, i = 0;
 401              p < memmap.map_end;
 402              p += memmap.desc_size, i++) {
 403                 md = p;
 404                 pr_info("mem%02u: type=%u, attr=0x%llx, range=[0x%016llx-0x%016llx) (%lluMB)\n",
 405                         i, md->type, md->attribute, md->phys_addr,
 406                         md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
 407                         (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
 408         }
 409 #endif  /*  EFI_DEBUG  */
 410 }
 411
 412 void __init efi_reserve_boot_services(void)
 413 {
 414         void *p;
 415
 416         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 417                 efi_memory_desc_t *md = p;
 418                 u64 start = md->phys_addr;
 419                 u64 size = md->num_pages << EFI_PAGE_SHIFT;
 420
 421                 if (md->type != EFI_BOOT_SERVICES_CODE &&
 422                     md->type != EFI_BOOT_SERVICES_DATA)
 423                         continue;
 424                 /* Only reserve where possible:
 425                  * - Not within any already allocated areas
 426                  * - Not over any memory area (really needed, if above?)
 427                  * - Not within any part of the kernel
 428                  * - Not the bios reserved area
 429                 */
 430                 if ((start + size > __pa_symbol(_text)
 431                                 && start <= __pa_symbol(_end)) ||
 432                         !e820_all_mapped(start, start+size, E820_RAM) ||
 433                         memblock_is_region_reserved(start, size)) {
 434                         /* Could not reserve, skip it */
 435                         md->num_pages = 0;
 436                         memblock_dbg("Could not reserve boot range [0x%010llx-0x%010llx]\n",
 437                                      start, start+size-1);
 438                 } else
 439                         memblock_reserve(start, size);
 440         }
 441 }
 442
 443 void __init efi_unmap_memmap(void)
 444 {
 445         clear_bit(EFI_MEMMAP, &efi.flags);
 446         if (memmap.map) {
 447                 early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size);
 448                 memmap.map = NULL;
 449         }
 450 }
 451
 452 void __init efi_free_boot_services(void)
 453 {
 454         void *p;
 455
 456         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 457                 efi_memory_desc_t *md = p;
 458                 unsigned long long start = md->phys_addr;
 459                 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
 460
 461                 if (md->type != EFI_BOOT_SERVICES_CODE &&
 462                     md->type != EFI_BOOT_SERVICES_DATA)
 463                         continue;
 464
 465                 /* Could not reserve boot area */
 466                 if (!size)
 467                         continue;
 468
 469                 free_bootmem_late(start, size);
 470         }
 471
 472         efi_unmap_memmap();
 473 }
 474
 475 static int __init efi_systab_init(void *phys)
 476 {
 477         if (efi_enabled(EFI_64BIT)) {
 478                 efi_system_table_64_t *systab64;
 479                 struct efi_setup_data *data = NULL;
 480                 u64 tmp = 0;
 481
 482                 if (efi_setup) {
 483                         data = early_memremap(efi_setup, sizeof(*data));
 484                         if (!data)
 485                                 return -ENOMEM;
 486                 }
 487                 systab64 = early_ioremap((unsigned long)phys,
 488                                          sizeof(*systab64));
 489                 if (systab64 == NULL) {
 490                         pr_err("Couldn't map the system table!\n");
 491                         if (data)
 492                                 early_iounmap(data, sizeof(*data));
 493                         return -ENOMEM;
 494                 }
 495
 496                 efi_systab.hdr = systab64->hdr;
 497                 efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor :
 498                                               systab64->fw_vendor;
 499                 tmp |= data ? data->fw_vendor : systab64->fw_vendor;
 500                 efi_systab.fw_revision = systab64->fw_revision;
 501                 efi_systab.con_in_handle = systab64->con_in_handle;
 502                 tmp |= systab64->con_in_handle;
 503                 efi_systab.con_in = systab64->con_in;
 504                 tmp |= systab64->con_in;
 505                 efi_systab.con_out_handle = systab64->con_out_handle;
 506                 tmp |= systab64->con_out_handle;
 507                 efi_systab.con_out = systab64->con_out;
 508                 tmp |= systab64->con_out;
 509                 efi_systab.stderr_handle = systab64->stderr_handle;
 510                 tmp |= systab64->stderr_handle;
 511                 efi_systab.stderr = systab64->stderr;
 512                 tmp |= systab64->stderr;
 513                 efi_systab.runtime = data ?
 514                                      (void *)(unsigned long)data->runtime :
 515                                      (void *)(unsigned long)systab64->runtime;
 516                 tmp |= data ? data->runtime : systab64->runtime;
 517                 efi_systab.boottime = (void *)(unsigned long)systab64->boottime;
 518                 tmp |= systab64->boottime;
 519                 efi_systab.nr_tables = systab64->nr_tables;
 520                 efi_systab.tables = data ? (unsigned long)data->tables :
 521                                            systab64->tables;
 522                 tmp |= data ? data->tables : systab64->tables;
 523
 524                 early_iounmap(systab64, sizeof(*systab64));
 525                 if (data)
 526                         early_iounmap(data, sizeof(*data));
 527 #ifdef CONFIG_X86_32
 528                 if (tmp >> 32) {
 529                         pr_err("EFI data located above 4GB, disabling EFI.\n");
 530                         return -EINVAL;
 531                 }
 532 #endif
 533         } else {
 534                 efi_system_table_32_t *systab32;
 535
 536                 systab32 = early_ioremap((unsigned long)phys,
 537                                          sizeof(*systab32));
 538                 if (systab32 == NULL) {
 539                         pr_err("Couldn't map the system table!\n");
 540                         return -ENOMEM;
 541                 }
 542
 543                 efi_systab.hdr = systab32->hdr;
 544                 efi_systab.fw_vendor = systab32->fw_vendor;
 545                 efi_systab.fw_revision = systab32->fw_revision;
 546                 efi_systab.con_in_handle = systab32->con_in_handle;
 547                 efi_systab.con_in = systab32->con_in;
 548                 efi_systab.con_out_handle = systab32->con_out_handle;
 549                 efi_systab.con_out = systab32->con_out;
 550                 efi_systab.stderr_handle = systab32->stderr_handle;
 551                 efi_systab.stderr = systab32->stderr;
 552                 efi_systab.runtime = (void *)(unsigned long)systab32->runtime;
 553                 efi_systab.boottime = (void *)(unsigned long)systab32->boottime;
 554                 efi_systab.nr_tables = systab32->nr_tables;
 555                 efi_systab.tables = systab32->tables;
 556
 557                 early_iounmap(systab32, sizeof(*systab32));
 558         }
 559
 560         efi.systab = &efi_systab;
 561
 562         /*
 563          * Verify the EFI Table
 564          */
 565         if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
 566                 pr_err("System table signature incorrect!\n");
 567                 return -EINVAL;
 568         }
 569         if ((efi.systab->hdr.revision >> 16) == 0)
 570                 pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n",
 571                        efi.systab->hdr.revision >> 16,
 572                        efi.systab->hdr.revision & 0xffff);
 573
 574         set_bit(EFI_SYSTEM_TABLES, &efi.flags);
 575
 576         return 0;
 577 }
 578
 579 static int __init efi_runtime_init32(void)
 580 {
 581         efi_runtime_services_32_t *runtime;
 582
 583         runtime = early_ioremap((unsigned long)efi.systab->runtime,
 584                         sizeof(efi_runtime_services_32_t));
 585         if (!runtime) {
 586                 pr_err("Could not map the runtime service table!\n");
 587                 return -ENOMEM;
 588         }
 589
 590         /*
 591          * We will only need *early* access to the following two
 592          * EFI runtime services before set_virtual_address_map
 593          * is invoked.
 594          */
 595         efi_phys.get_time = (efi_get_time_t *)
 596                         (unsigned long)runtime->get_time;
 597         efi_phys.set_virtual_address_map =
 598                         (efi_set_virtual_address_map_t *)
 599                         (unsigned long)runtime->set_virtual_address_map;
 600         /*
 601          * Make efi_get_time can be called before entering
 602          * virtual mode.
 603          */
 604         efi.get_time = phys_efi_get_time;
 605         early_iounmap(runtime, sizeof(efi_runtime_services_32_t));
 606
 607         return 0;
 608 }
 609
 610 static int __init efi_runtime_init64(void)
 611 {
 612         efi_runtime_services_64_t *runtime;
 613
 614         runtime = early_ioremap((unsigned long)efi.systab->runtime,
 615                         sizeof(efi_runtime_services_64_t));
 616         if (!runtime) {
 617                 pr_err("Could not map the runtime service table!\n");
 618                 return -ENOMEM;
 619         }
 620
 621         /*
 622          * We will only need *early* access to the following two
 623          * EFI runtime services before set_virtual_address_map
 624          * is invoked.
 625          */
 626         efi_phys.get_time = (efi_get_time_t *)
 627                         (unsigned long)runtime->get_time;
 628         efi_phys.set_virtual_address_map =
 629                         (efi_set_virtual_address_map_t *)
 630                         (unsigned long)runtime->set_virtual_address_map;
 631         /*
 632          * Make efi_get_time can be called before entering
 633          * virtual mode.
 634          */
 635         efi.get_time = phys_efi_get_time;
 636         early_iounmap(runtime, sizeof(efi_runtime_services_64_t));
 637
 638         return 0;
 639 }
 640
 641 static int __init efi_runtime_init(void)
 642 {
 643         int rv;
 644
 645         /*
 646          * Check out the runtime services table. We need to map
 647          * the runtime services table so that we can grab the physical
 648          * address of several of the EFI runtime functions, needed to
 649          * set the firmware into virtual mode.
 650          */
 651         if (efi_enabled(EFI_64BIT))
 652                 rv = efi_runtime_init64();
 653         else
 654                 rv = efi_runtime_init32();
 655
 656         if (rv)
 657                 return rv;
 658
 659         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 660
 661         return 0;
 662 }
 663
 664 static int __init efi_memmap_init(void)
 665 {
 666         /* Map the EFI memory map */
 667         memmap.map = early_ioremap((unsigned long)memmap.phys_map,
 668                                    memmap.nr_map * memmap.desc_size);
 669         if (memmap.map == NULL) {
 670                 pr_err("Could not map the memory map!\n");
 671                 return -ENOMEM;
 672         }
 673         memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
 674
 675         if (add_efi_memmap)
 676                 do_add_efi_memmap();
 677
 678         set_bit(EFI_MEMMAP, &efi.flags);
 679
 680         return 0;
 681 }
 682
 683 /*
 684  * A number of config table entries get remapped to virtual addresses
 685  * after entering EFI virtual mode. However, the kexec kernel requires
 686  * their physical addresses therefore we pass them via setup_data and
 687  * correct those entries to their respective physical addresses here.
 688  *
 689  * Currently only handles smbios which is necessary for some firmware
 690  * implementation.
 691  */
 692 static int __init efi_reuse_config(u64 tables, int nr_tables)
 693 {
 694         int i, sz, ret = 0;
 695         void *p, *tablep;
 696         struct efi_setup_data *data;
 697
 698         if (!efi_setup)
 699                 return 0;
 700
 701         if (!efi_enabled(EFI_64BIT))
 702                 return 0;
 703
 704         data = early_memremap(efi_setup, sizeof(*data));
 705         if (!data) {
 706                 ret = -ENOMEM;
 707                 goto out;
 708         }
 709
 710         if (!data->smbios)
 711                 goto out_memremap;
 712
 713         sz = sizeof(efi_config_table_64_t);
 714
 715         p = tablep = early_memremap(tables, nr_tables * sz);
 716         if (!p) {
 717                 pr_err("Could not map Configuration table!\n");
 718                 ret = -ENOMEM;
 719                 goto out_memremap;
 720         }
 721
 722         for (i = 0; i < efi.systab->nr_tables; i++) {
 723                 efi_guid_t guid;
 724
 725                 guid = ((efi_config_table_64_t *)p)->guid;
 726
 727                 if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID))
 728                         ((efi_config_table_64_t *)p)->table = data->smbios;
 729                 p += sz;
 730         }
 731         early_iounmap(tablep, nr_tables * sz);
 732
 733 out_memremap:
 734         early_iounmap(data, sizeof(*data));
 735 out:
 736         return ret;
 737 }
 738
 739 void __init efi_init(void)
 740 {
 741         efi_char16_t *c16;
 742         char vendor[100] = "unknown";
 743         int i = 0;
 744         void *tmp;
 745
 746 #ifdef CONFIG_X86_32
 747         if (boot_params.efi_info.efi_systab_hi ||
 748             boot_params.efi_info.efi_memmap_hi) {
 749                 pr_info("Table located above 4GB, disabling EFI.\n");
 750                 return;
 751         }
 752         efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
 753 #else
 754         efi_phys.systab = (efi_system_table_t *)
 755                           (boot_params.efi_info.efi_systab |
 756                           ((__u64)boot_params.efi_info.efi_systab_hi<<32));
 757 #endif
 758
 759         if (efi_systab_init(efi_phys.systab))
 760                 return;
 761
 762         set_bit(EFI_SYSTEM_TABLES, &efi.flags);
 763
 764         efi.config_table = (unsigned long)efi.systab->tables;
 765         efi.fw_vendor    = (unsigned long)efi.systab->fw_vendor;
 766         efi.runtime      = (unsigned long)efi.systab->runtime;
 767
 768         /*
 769          * Show what we know for posterity
 770          */
 771         c16 = tmp = early_ioremap(efi.systab->fw_vendor, 2);
 772         if (c16) {
 773                 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
 774                         vendor[i] = *c16++;
 775                 vendor[i] = '\0';
 776         } else
 777                 pr_err("Could not map the firmware vendor!\n");
 778         early_iounmap(tmp, 2);
 779
 780         pr_info("EFI v%u.%.02u by %s\n",
 781                 efi.systab->hdr.revision >> 16,
 782                 efi.systab->hdr.revision & 0xffff, vendor);
 783
 784         if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables))
 785                 return;
 786
 787         if (efi_config_init(arch_tables))
 788                 return;
 789
 790         /*
 791          * Note: We currently don't support runtime services on an EFI
 792          * that doesn't match the kernel 32/64-bit mode.
 793          */
 794
 795         if (!efi_runtime_supported())
 796                 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
 797         else {
 798                 if (disable_runtime || efi_runtime_init())
 799                         return;
 800         }
 801         if (efi_memmap_init())
 802                 return;
 803
 804         set_bit(EFI_MEMMAP, &efi.flags);
 805
 806         print_efi_memmap();
 807 }
 808
 809 void __init efi_late_init(void)
 810 {
 811         efi_bgrt_init();
 812 }
 813
 814 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
 815 {
 816         u64 addr, npages;
 817
 818         addr = md->virt_addr;
 819         npages = md->num_pages;
 820
 821         memrange_efi_to_native(&addr, &npages);
 822
 823         if (executable)
 824                 set_memory_x(addr, npages);
 825         else
 826                 set_memory_nx(addr, npages);
 827 }
 828
 829 void __init runtime_code_page_mkexec(void)
 830 {
 831         efi_memory_desc_t *md;
 832         void *p;
 833
 834         /* Make EFI runtime service code area executable */
 835         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 836                 md = p;
 837
 838                 if (md->type != EFI_RUNTIME_SERVICES_CODE)
 839                         continue;
 840
 841                 efi_set_executable(md, true);
 842         }
 843 }
 844
 845 void efi_memory_uc(u64 addr, unsigned long size)
 846 {
 847         unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
 848         u64 npages;
 849
 850         npages = round_up(size, page_shift) / page_shift;
 851         memrange_efi_to_native(&addr, &npages);
 852         set_memory_uc(addr, npages);
 853 }
 854
 855 void __init old_map_region(efi_memory_desc_t *md)
 856 {
 857         u64 start_pfn, end_pfn, end;
 858         unsigned long size;
 859         void *va;
 860
 861         start_pfn = PFN_DOWN(md->phys_addr);
 862         size      = md->num_pages << PAGE_SHIFT;
 863         end       = md->phys_addr + size;
 864         end_pfn   = PFN_UP(end);
 865
 866         if (pfn_range_is_mapped(start_pfn, end_pfn)) {
 867                 va = __va(md->phys_addr);
 868
 869                 if (!(md->attribute & EFI_MEMORY_WB))
 870                         efi_memory_uc((u64)(unsigned long)va, size);
 871         } else
 872                 va = efi_ioremap(md->phys_addr, size,
 873                                  md->type, md->attribute);
 874
 875         md->virt_addr = (u64) (unsigned long) va;
 876         if (!va)
 877                 pr_err("ioremap of 0x%llX failed!\n",
 878                        (unsigned long long)md->phys_addr);
 879 }
 880
 881 static void native_runtime_setup(void)
 882 {
 883         efi.get_time = virt_efi_get_time;
 884         efi.set_time = virt_efi_set_time;
 885         efi.get_wakeup_time = virt_efi_get_wakeup_time;
 886         efi.set_wakeup_time = virt_efi_set_wakeup_time;
 887         efi.get_variable = virt_efi_get_variable;
 888         efi.get_next_variable = virt_efi_get_next_variable;
 889         efi.set_variable = virt_efi_set_variable;
 890         efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
 891         efi.reset_system = virt_efi_reset_system;
 892         efi.query_variable_info = virt_efi_query_variable_info;
 893         efi.update_capsule = virt_efi_update_capsule;
 894         efi.query_capsule_caps = virt_efi_query_capsule_caps;
 895 }
 896
 897 /* Merge contiguous regions of the same type and attribute */
 898 static void __init efi_merge_regions(void)
 899 {
 900         void *p;
 901         efi_memory_desc_t *md, *prev_md = NULL;
 902
 903         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 904                 u64 prev_size;
 905                 md = p;
 906
 907                 if (!prev_md) {
 908                         prev_md = md;
 909                         continue;
 910                 }
 911
 912                 if (prev_md->type != md->type ||
 913                     prev_md->attribute != md->attribute) {
 914                         prev_md = md;
 915                         continue;
 916                 }
 917
 918                 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
 919
 920                 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
 921                         prev_md->num_pages += md->num_pages;
 922                         md->type = EFI_RESERVED_TYPE;
 923                         md->attribute = 0;
 924                         continue;
 925                 }
 926                 prev_md = md;
 927         }
 928 }
 929
 930 static void __init get_systab_virt_addr(efi_memory_desc_t *md)
 931 {
 932         unsigned long size;
 933         u64 end, systab;
 934
 935         size = md->num_pages << EFI_PAGE_SHIFT;
 936         end = md->phys_addr + size;
 937         systab = (u64)(unsigned long)efi_phys.systab;
 938         if (md->phys_addr <= systab && systab < end) {
 939                 systab += md->virt_addr - md->phys_addr;
 940                 efi.systab = (efi_system_table_t *)(unsigned long)systab;
 941         }
 942 }
 943
 944 static void __init save_runtime_map(void)
 945 {
 946 #ifdef CONFIG_KEXEC
 947         efi_memory_desc_t *md;
 948         void *tmp, *p, *q = NULL;
 949         int count = 0;
 950
 951         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 952                 md = p;
 953
 954                 if (!(md->attribute & EFI_MEMORY_RUNTIME) ||
 955                     (md->type == EFI_BOOT_SERVICES_CODE) ||
 956                     (md->type == EFI_BOOT_SERVICES_DATA))
 957                         continue;
 958                 tmp = krealloc(q, (count + 1) * memmap.desc_size, GFP_KERNEL);
 959                 if (!tmp)
 960                         goto out;
 961                 q = tmp;
 962
 963                 memcpy(q + count * memmap.desc_size, md, memmap.desc_size);
 964                 count++;
 965         }
 966
 967         efi_runtime_map_setup(q, count, memmap.desc_size);
 968         return;
 969
 970 out:
 971         kfree(q);
 972         pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
 973 #endif
 974 }
 975
 976 static void *realloc_pages(void *old_memmap, int old_shift)
 977 {
 978         void *ret;
 979
 980         ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
 981         if (!ret)
 982                 goto out;
 983
 984         /*
 985          * A first-time allocation doesn't have anything to copy.
 986          */
 987         if (!old_memmap)
 988                 return ret;
 989
 990         memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
 991
 992 out:
 993         free_pages((unsigned long)old_memmap, old_shift);
 994         return ret;
 995 }
 996
 997 /*
 998  * Map the efi memory ranges of the runtime services and update new_mmap with
 999  * virtual addresses.
1000  */
1001 static void * __init efi_map_regions(int *count, int *pg_shift)
1002 {
1003         void *p, *new_memmap = NULL;
1004         unsigned long left = 0;
1005         efi_memory_desc_t *md;
1006
1007         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1008                 md = p;
1009                 if (!(md->attribute & EFI_MEMORY_RUNTIME)) {
1010 #ifdef CONFIG_X86_64
1011                         if (md->type != EFI_BOOT_SERVICES_CODE &&
1012                             md->type != EFI_BOOT_SERVICES_DATA)
1013 #endif
1014                                 continue;
1015                 }
1016
1017                 efi_map_region(md);
1018                 get_systab_virt_addr(md);
1019
1020                 if (left < memmap.desc_size) {
1021                         new_memmap = realloc_pages(new_memmap, *pg_shift);
1022                         if (!new_memmap)
1023                                 return NULL;
1024
1025                         left += PAGE_SIZE << *pg_shift;
1026                         (*pg_shift)++;
1027                 }
1028
1029                 memcpy(new_memmap + (*count * memmap.desc_size), md,
1030                        memmap.desc_size);
1031
1032                 left -= memmap.desc_size;
1033                 (*count)++;
1034         }
1035
1036         return new_memmap;
1037 }
1038
1039 static void __init kexec_enter_virtual_mode(void)
1040 {
1041 #ifdef CONFIG_KEXEC
1042         efi_memory_desc_t *md;
1043         void *p;
1044
1045         efi.systab = NULL;
1046
1047         /*
1048          * We don't do virtual mode, since we don't do runtime services, on
1049          * non-native EFI
1050          */
1051         if (!efi_is_native()) {
1052                 efi_unmap_memmap();
1053                 return;
1054         }
1055
1056         /*
1057         * Map efi regions which were passed via setup_data. The virt_addr is a
1058         * fixed addr which was used in first kernel of a kexec boot.
1059         */
1060         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1061                 md = p;
1062                 efi_map_region_fixed(md); /* FIXME: add error handling */
1063                 get_systab_virt_addr(md);
1064         }
1065
1066         save_runtime_map();
1067
1068         BUG_ON(!efi.systab);
1069
1070         efi_sync_low_kernel_mappings();
1071
1072         /*
1073          * Now that EFI is in virtual mode, update the function
1074          * pointers in the runtime service table to the new virtual addresses.
1075          *
1076          * Call EFI services through wrapper functions.
1077          */
1078         efi.runtime_version = efi_systab.hdr.revision;
1079
1080         native_runtime_setup();
1081
1082         efi.set_virtual_address_map = NULL;
1083
1084         if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
1085                 runtime_code_page_mkexec();
1086
1087         /* clean DUMMY object */
1088         efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
1089                          EFI_VARIABLE_NON_VOLATILE |
1090                          EFI_VARIABLE_BOOTSERVICE_ACCESS |
1091                          EFI_VARIABLE_RUNTIME_ACCESS,
1092                          0, NULL);
1093 #endif
1094 }
1095
1096 /*
1097  * This function will switch the EFI runtime services to virtual mode.
1098  * Essentially, we look through the EFI memmap and map every region that
1099  * has the runtime attribute bit set in its memory descriptor into the
1100  * ->trampoline_pgd page table using a top-down VA allocation scheme.
1101  *
1102  * The old method which used to update that memory descriptor with the
1103  * virtual address obtained from ioremap() is still supported when the
1104  * kernel is booted with efi=old_map on its command line. Same old
1105  * method enabled the runtime services to be called without having to
1106  * thunk back into physical mode for every invocation.
1107  *
1108  * The new method does a pagetable switch in a preemption-safe manner
1109  * so that we're in a different address space when calling a runtime
1110  * function. For function arguments passing we do copy the PGDs of the
1111  * kernel page table into ->trampoline_pgd prior to each call.
1112  *
1113  * Specially for kexec boot, efi runtime maps in previous kernel should
1114  * be passed in via setup_data. In that case runtime ranges will be mapped
1115  * to the same virtual addresses as the first kernel, see
1116  * kexec_enter_virtual_mode().
1117  */
1118 static void __init __efi_enter_virtual_mode(void)
1119 {
1120         int count = 0, pg_shift = 0;
1121         void *new_memmap = NULL;
1122         efi_status_t status;
1123
1124         efi.systab = NULL;
1125
1126         efi_merge_regions();
1127         new_memmap = efi_map_regions(&count, &pg_shift);
1128         if (!new_memmap) {
1129                 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
1130                 return;
1131         }
1132
1133         save_runtime_map();
1134
1135         BUG_ON(!efi.systab);
1136
1137         if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift))
1138                 return;
1139
1140         efi_sync_low_kernel_mappings();
1141         efi_dump_pagetable();
1142
1143         if (efi_is_native()) {
1144                 status = phys_efi_set_virtual_address_map(
1145                                 memmap.desc_size * count,
1146                                 memmap.desc_size,
1147                                 memmap.desc_version,
1148                                 (efi_memory_desc_t *)__pa(new_memmap));
1149         } else {
1150                 status = efi_thunk_set_virtual_address_map(
1151                                 efi_phys.set_virtual_address_map,
1152                                 memmap.desc_size * count,
1153                                 memmap.desc_size,
1154                                 memmap.desc_version,
1155                                 (efi_memory_desc_t *)__pa(new_memmap));
1156         }
1157
1158         if (status != EFI_SUCCESS) {
1159                 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
1160                          status);
1161                 panic("EFI call to SetVirtualAddressMap() failed!");
1162         }
1163
1164         /*
1165          * Now that EFI is in virtual mode, update the function
1166          * pointers in the runtime service table to the new virtual addresses.
1167          *
1168          * Call EFI services through wrapper functions.
1169          */
1170         efi.runtime_version = efi_systab.hdr.revision;
1171
1172         if (efi_is_native())
1173                 native_runtime_setup();
1174         else
1175                 efi_thunk_runtime_setup();
1176
1177         efi.set_virtual_address_map = NULL;
1178
1179         efi_runtime_mkexec();
1180
1181         /*
1182          * We mapped the descriptor array into the EFI pagetable above but we're
1183          * not unmapping it here. Here's why:
1184          *
1185          * We're copying select PGDs from the kernel page table to the EFI page
1186          * table and when we do so and make changes to those PGDs like unmapping
1187          * stuff from them, those changes appear in the kernel page table and we
1188          * go boom.
1189          *
1190          * From setup_real_mode():
1191          *
1192          * ...
1193          * trampoline_pgd[0] = init_level4_pgt[pgd_index(__PAGE_OFFSET)].pgd;
1194          *
1195          * In this particular case, our allocation is in PGD 0 of the EFI page
1196          * table but we've copied that PGD from PGD[272] of the EFI page table:
1197          *
1198          *      pgd_index(__PAGE_OFFSET = 0xffff880000000000) = 272
1199          *
1200          * where the direct memory mapping in kernel space is.
1201          *
1202          * new_memmap's VA comes from that direct mapping and thus clearing it,
1203          * it would get cleared in the kernel page table too.
1204          *
1205          * efi_cleanup_page_tables(__pa(new_memmap), 1 << pg_shift);
1206          */
1207         free_pages((unsigned long)new_memmap, pg_shift);
1208
1209         /* clean DUMMY object */
1210         efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
1211                          EFI_VARIABLE_NON_VOLATILE |
1212                          EFI_VARIABLE_BOOTSERVICE_ACCESS |
1213                          EFI_VARIABLE_RUNTIME_ACCESS,
1214                          0, NULL);
1215 }
1216
1217 void __init efi_enter_virtual_mode(void)
1218 {
1219         if (efi_setup)
1220                 kexec_enter_virtual_mode();
1221         else
1222                 __efi_enter_virtual_mode();
1223 }
1224
1225 /*
1226  * Convenience functions to obtain memory types and attributes
1227  */
1228 u32 efi_mem_type(unsigned long phys_addr)
1229 {
1230         efi_memory_desc_t *md;
1231         void *p;
1232
1233         if (!efi_enabled(EFI_MEMMAP))
1234                 return 0;
1235
1236         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1237                 md = p;
1238                 if ((md->phys_addr <= phys_addr) &&
1239                     (phys_addr < (md->phys_addr +
1240                                   (md->num_pages << EFI_PAGE_SHIFT))))
1241                         return md->type;
1242         }
1243         return 0;
1244 }
1245
1246 u64 efi_mem_attributes(unsigned long phys_addr)
1247 {
1248         efi_memory_desc_t *md;
1249         void *p;
1250
1251         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1252                 md = p;
1253                 if ((md->phys_addr <= phys_addr) &&
1254                     (phys_addr < (md->phys_addr +
1255                                   (md->num_pages << EFI_PAGE_SHIFT))))
1256                         return md->attribute;
1257         }
1258         return 0;
1259 }
1260
1261 /*
1262  * Some firmware implementations refuse to boot if there's insufficient space
1263  * in the variable store. Ensure that we never use more than a safe limit.
1264  *
1265  * Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable
1266  * store.
1267  */
1268 efi_status_t efi_query_variable_store(u32 attributes, unsigned long size)
1269 {
1270         efi_status_t status;
1271         u64 storage_size, remaining_size, max_size;
1272
1273         if (!(attributes & EFI_VARIABLE_NON_VOLATILE))
1274                 return 0;
1275
1276         status = efi.query_variable_info(attributes, &storage_size,
1277                                          &remaining_size, &max_size);
1278         if (status != EFI_SUCCESS)
1279                 return status;
1280
1281         /*
1282          * We account for that by refusing the write if permitting it would
1283          * reduce the available space to under 5KB. This figure was provided by
1284          * Samsung, so should be safe.
1285          */
1286         if ((remaining_size - size < EFI_MIN_RESERVE) &&
1287                 !efi_no_storage_paranoia) {
1288
1289                 /*
1290                  * Triggering garbage collection may require that the firmware
1291                  * generate a real EFI_OUT_OF_RESOURCES error. We can force
1292                  * that by attempting to use more space than is available.
1293                  */
1294                 unsigned long dummy_size = remaining_size + 1024;
1295                 void *dummy = kzalloc(dummy_size, GFP_ATOMIC);
1296
1297                 if (!dummy)
1298                         return EFI_OUT_OF_RESOURCES;
1299
1300                 status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
1301                                           EFI_VARIABLE_NON_VOLATILE |
1302                                           EFI_VARIABLE_BOOTSERVICE_ACCESS |
1303                                           EFI_VARIABLE_RUNTIME_ACCESS,
1304                                           dummy_size, dummy);
1305
1306                 if (status == EFI_SUCCESS) {
1307                         /*
1308                          * This should have failed, so if it didn't make sure
1309                          * that we delete it...
1310                          */
1311                         efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
1312                                          EFI_VARIABLE_NON_VOLATILE |
1313                                          EFI_VARIABLE_BOOTSERVICE_ACCESS |
1314                                          EFI_VARIABLE_RUNTIME_ACCESS,
1315                                          0, dummy);
1316                 }
1317
1318                 kfree(dummy);
1319
1320                 /*
1321                  * The runtime code may now have triggered a garbage collection
1322                  * run, so check the variable info again
1323                  */
1324                 status = efi.query_variable_info(attributes, &storage_size,
1325                                                  &remaining_size, &max_size);
1326
1327                 if (status != EFI_SUCCESS)
1328                         return status;
1329
1330                 /*
1331                  * There still isn't enough room, so return an error
1332                  */
1333                 if (remaining_size - size < EFI_MIN_RESERVE)
1334                         return EFI_OUT_OF_RESOURCES;
1335         }
1336
1337         return EFI_SUCCESS;
1338 }
1339 EXPORT_SYMBOL_GPL(efi_query_variable_store);
1340
1341 static int __init parse_efi_cmdline(char *str)
1342 {
1343         if (*str == '=')
1344                 str++;
1345
1346         if (!strncmp(str, "old_map", 7))
1347                 set_bit(EFI_OLD_MEMMAP, &efi.flags);
1348
1349         return 0;
1350 }
1351 early_param("efi", parse_efi_cmdline);
1352
1353 void __init efi_apply_memmap_quirks(void)
1354 {
1355         /*
1356          * Once setup is done earlier, unmap the EFI memory map on mismatched
1357          * firmware/kernel architectures since there is no support for runtime
1358          * services.
1359          */
1360         if (!efi_runtime_supported()) {
1361                 pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n");
1362                 efi_unmap_memmap();
1363         }
1364
1365         /*
1366          * UV doesn't support the new EFI pagetable mapping yet.
1367          */
1368         if (is_uv_system())
1369                 set_bit(EFI_OLD_MEMMAP, &efi.flags);
1370 }