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  *
  16  * Copied from efi_32.c to eliminate the duplicated code between EFI
  17  * 32/64 support code. --ying 2007-10-26
  18  *
  19  * All EFI Runtime Services are not implemented yet as EFI only
  20  * supports physical mode addressing on SoftSDV. This is to be fixed
  21  * in a future version.  --drummond 1999-07-20
  22  *
  23  * Implemented EFI runtime services and virtual mode calls.  --davidm
  24  *
  25  * Goutham Rao: <goutham.rao@intel.com>
  26  *      Skip non-WB memory and ignore empty memory ranges.
  27  */
  28
  29 #include <linux/kernel.h>
  30 #include <linux/init.h>
  31 #include <linux/efi.h>
  32 #include <linux/bootmem.h>
  33 #include <linux/memblock.h>
  34 #include <linux/spinlock.h>
  35 #include <linux/uaccess.h>
  36 #include <linux/time.h>
  37 #include <linux/io.h>
  38 #include <linux/reboot.h>
  39 #include <linux/bcd.h>
  40
  41 #include <asm/setup.h>
  42 #include <asm/efi.h>
  43 #include <asm/time.h>
  44 #include <asm/cacheflush.h>
  45 #include <asm/tlbflush.h>
  46 #include <asm/x86_init.h>
  47
  48 #define EFI_DEBUG       1
  49 #define PFX             "EFI: "
  50
  51 int efi_enabled;
  52 EXPORT_SYMBOL(efi_enabled);
  53
  54 struct efi __read_mostly efi = {
  55         .mps        = EFI_INVALID_TABLE_ADDR,
  56         .acpi       = EFI_INVALID_TABLE_ADDR,
  57         .acpi20     = EFI_INVALID_TABLE_ADDR,
  58         .smbios     = EFI_INVALID_TABLE_ADDR,
  59         .sal_systab = EFI_INVALID_TABLE_ADDR,
  60         .boot_info  = EFI_INVALID_TABLE_ADDR,
  61         .hcdp       = EFI_INVALID_TABLE_ADDR,
  62         .uga        = EFI_INVALID_TABLE_ADDR,
  63         .uv_systab  = EFI_INVALID_TABLE_ADDR,
  64 };
  65 EXPORT_SYMBOL(efi);
  66
  67 struct efi_memory_map memmap;
  68
  69 static struct efi efi_phys __initdata;
  70 static efi_system_table_t efi_systab __initdata;
  71
  72 static int __init setup_noefi(char *arg)
  73 {
  74         efi_enabled = 0;
  75         return 0;
  76 }
  77 early_param("noefi", setup_noefi);
  78
  79 int add_efi_memmap;
  80 EXPORT_SYMBOL(add_efi_memmap);
  81
  82 static int __init setup_add_efi_memmap(char *arg)
  83 {
  84         add_efi_memmap = 1;
  85         return 0;
  86 }
  87 early_param("add_efi_memmap", setup_add_efi_memmap);
  88
  89
  90 static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
  91 {
  92         unsigned long flags;
  93         efi_status_t status;
  94
  95         spin_lock_irqsave(&rtc_lock, flags);
  96         status = efi_call_virt2(get_time, tm, tc);
  97         spin_unlock_irqrestore(&rtc_lock, flags);
  98         return status;
  99 }
 100
 101 static efi_status_t virt_efi_set_time(efi_time_t *tm)
 102 {
 103         unsigned long flags;
 104         efi_status_t status;
 105
 106         spin_lock_irqsave(&rtc_lock, flags);
 107         status = efi_call_virt1(set_time, tm);
 108         spin_unlock_irqrestore(&rtc_lock, flags);
 109         return status;
 110 }
 111
 112 static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
 113                                              efi_bool_t *pending,
 114                                              efi_time_t *tm)
 115 {
 116         unsigned long flags;
 117         efi_status_t status;
 118
 119         spin_lock_irqsave(&rtc_lock, flags);
 120         status = efi_call_virt3(get_wakeup_time,
 121                                 enabled, pending, tm);
 122         spin_unlock_irqrestore(&rtc_lock, flags);
 123         return status;
 124 }
 125
 126 static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 127 {
 128         unsigned long flags;
 129         efi_status_t status;
 130
 131         spin_lock_irqsave(&rtc_lock, flags);
 132         status = efi_call_virt2(set_wakeup_time,
 133                                 enabled, tm);
 134         spin_unlock_irqrestore(&rtc_lock, flags);
 135         return status;
 136 }
 137
 138 static efi_status_t virt_efi_get_variable(efi_char16_t *name,
 139                                           efi_guid_t *vendor,
 140                                           u32 *attr,
 141                                           unsigned long *data_size,
 142                                           void *data)
 143 {
 144         return efi_call_virt5(get_variable,
 145                               name, vendor, attr,
 146                               data_size, data);
 147 }
 148
 149 static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
 150                                                efi_char16_t *name,
 151                                                efi_guid_t *vendor)
 152 {
 153         return efi_call_virt3(get_next_variable,
 154                               name_size, name, vendor);
 155 }
 156
 157 static efi_status_t virt_efi_set_variable(efi_char16_t *name,
 158                                           efi_guid_t *vendor,
 159                                           u32 attr,
 160                                           unsigned long data_size,
 161                                           void *data)
 162 {
 163         return efi_call_virt5(set_variable,
 164                               name, vendor, attr,
 165                               data_size, data);
 166 }
 167
 168 static efi_status_t virt_efi_query_variable_info(u32 attr,
 169                                                  u64 *storage_space,
 170                                                  u64 *remaining_space,
 171                                                  u64 *max_variable_size)
 172 {
 173         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 174                 return EFI_UNSUPPORTED;
 175
 176         return efi_call_virt4(query_variable_info, attr, storage_space,
 177                               remaining_space, max_variable_size);
 178 }
 179
 180 static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
 181 {
 182         return efi_call_virt1(get_next_high_mono_count, count);
 183 }
 184
 185 static void virt_efi_reset_system(int reset_type,
 186                                   efi_status_t status,
 187                                   unsigned long data_size,
 188                                   efi_char16_t *data)
 189 {
 190         efi_call_virt4(reset_system, reset_type, status,
 191                        data_size, data);
 192 }
 193
 194 static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
 195                                             unsigned long count,
 196                                             unsigned long sg_list)
 197 {
 198         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 199                 return EFI_UNSUPPORTED;
 200
 201         return efi_call_virt3(update_capsule, capsules, count, sg_list);
 202 }
 203
 204 static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
 205                                                 unsigned long count,
 206                                                 u64 *max_size,
 207                                                 int *reset_type)
 208 {
 209         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 210                 return EFI_UNSUPPORTED;
 211
 212         return efi_call_virt4(query_capsule_caps, capsules, count, max_size,
 213                               reset_type);
 214 }
 215
 216 static efi_status_t __init phys_efi_set_virtual_address_map(
 217         unsigned long memory_map_size,
 218         unsigned long descriptor_size,
 219         u32 descriptor_version,
 220         efi_memory_desc_t *virtual_map)
 221 {
 222         efi_status_t status;
 223
 224         efi_call_phys_prelog();
 225         status = efi_call_phys4(efi_phys.set_virtual_address_map,
 226                                 memory_map_size, descriptor_size,
 227                                 descriptor_version, virtual_map);
 228         efi_call_phys_epilog();
 229         return status;
 230 }
 231
 232 static efi_status_t __init phys_efi_get_time(efi_time_t *tm,
 233                                              efi_time_cap_t *tc)
 234 {
 235         unsigned long flags;
 236         efi_status_t status;
 237
 238         spin_lock_irqsave(&rtc_lock, flags);
 239         efi_call_phys_prelog();
 240         status = efi_call_phys2(efi_phys.get_time, tm, tc);
 241         efi_call_phys_epilog();
 242         spin_unlock_irqrestore(&rtc_lock, flags);
 243         return status;
 244 }
 245
 246 int efi_set_rtc_mmss(unsigned long nowtime)
 247 {
 248         int real_seconds, real_minutes;
 249         efi_status_t    status;
 250         efi_time_t      eft;
 251         efi_time_cap_t  cap;
 252
 253         status = efi.get_time(&eft, &cap);
 254         if (status != EFI_SUCCESS) {
 255                 printk(KERN_ERR "Oops: efitime: can't read time!\n");
 256                 return -1;
 257         }
 258
 259         real_seconds = nowtime % 60;
 260         real_minutes = nowtime / 60;
 261         if (((abs(real_minutes - eft.minute) + 15)/30) & 1)
 262                 real_minutes += 30;
 263         real_minutes %= 60;
 264         eft.minute = real_minutes;
 265         eft.second = real_seconds;
 266
 267         status = efi.set_time(&eft);
 268         if (status != EFI_SUCCESS) {
 269                 printk(KERN_ERR "Oops: efitime: can't write time!\n");
 270                 return -1;
 271         }
 272         return 0;
 273 }
 274
 275 unsigned long efi_get_time(void)
 276 {
 277         efi_status_t status;
 278         efi_time_t eft;
 279         efi_time_cap_t cap;
 280
 281         status = efi.get_time(&eft, &cap);
 282         if (status != EFI_SUCCESS)
 283                 printk(KERN_ERR "Oops: efitime: can't read time!\n");
 284
 285         return mktime(eft.year, eft.month, eft.day, eft.hour,
 286                       eft.minute, eft.second);
 287 }
 288
 289 /*
 290  * Tell the kernel about the EFI memory map.  This might include
 291  * more than the max 128 entries that can fit in the e820 legacy
 292  * (zeropage) memory map.
 293  */
 294
 295 static void __init do_add_efi_memmap(void)
 296 {
 297         void *p;
 298
 299         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 300                 efi_memory_desc_t *md = p;
 301                 unsigned long long start = md->phys_addr;
 302                 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
 303                 int e820_type;
 304
 305                 switch (md->type) {
 306                 case EFI_LOADER_CODE:
 307                 case EFI_LOADER_DATA:
 308                 case EFI_BOOT_SERVICES_CODE:
 309                 case EFI_BOOT_SERVICES_DATA:
 310                 case EFI_CONVENTIONAL_MEMORY:
 311                         if (md->attribute & EFI_MEMORY_WB)
 312                                 e820_type = E820_RAM;
 313                         else
 314                                 e820_type = E820_RESERVED;
 315                         break;
 316                 case EFI_ACPI_RECLAIM_MEMORY:
 317                         e820_type = E820_ACPI;
 318                         break;
 319                 case EFI_ACPI_MEMORY_NVS:
 320                         e820_type = E820_NVS;
 321                         break;
 322                 case EFI_UNUSABLE_MEMORY:
 323                         e820_type = E820_UNUSABLE;
 324                         break;
 325                 default:
 326                         /*
 327                          * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
 328                          * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
 329                          * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
 330                          */
 331                         e820_type = E820_RESERVED;
 332                         break;
 333                 }
 334                 e820_add_region(start, size, e820_type);
 335         }
 336         sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 337 }
 338
 339 void __init efi_memblock_x86_reserve_range(void)
 340 {
 341         unsigned long pmap;
 342
 343 #ifdef CONFIG_X86_32
 344         pmap = boot_params.efi_info.efi_memmap;
 345 #else
 346         pmap = (boot_params.efi_info.efi_memmap |
 347                 ((__u64)boot_params.efi_info.efi_memmap_hi<<32));
 348 #endif
 349         memmap.phys_map = (void *)pmap;
 350         memmap.nr_map = boot_params.efi_info.efi_memmap_size /
 351                 boot_params.efi_info.efi_memdesc_size;
 352         memmap.desc_version = boot_params.efi_info.efi_memdesc_version;
 353         memmap.desc_size = boot_params.efi_info.efi_memdesc_size;
 354         memblock_x86_reserve_range(pmap, pmap + memmap.nr_map * memmap.desc_size,
 355                       "EFI memmap");
 356 }
 357
 358 #if EFI_DEBUG
 359 static void __init print_efi_memmap(void)
 360 {
 361         efi_memory_desc_t *md;
 362         void *p;
 363         int i;
 364
 365         for (p = memmap.map, i = 0;
 366              p < memmap.map_end;
 367              p += memmap.desc_size, i++) {
 368                 md = p;
 369                 printk(KERN_INFO PFX "mem%02u: type=%u, attr=0x%llx, "
 370                         "range=[0x%016llx-0x%016llx) (%lluMB)\n",
 371                         i, md->type, md->attribute, md->phys_addr,
 372                         md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
 373                         (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
 374         }
 375 }
 376 #endif  /*  EFI_DEBUG  */
 377
 378 void __init efi_reserve_boot_services(void)
 379 {
 380         void *p;
 381
 382         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 383                 efi_memory_desc_t *md = p;
 384                 u64 start = md->phys_addr;
 385                 u64 size = md->num_pages << EFI_PAGE_SHIFT;
 386
 387                 if (md->type != EFI_BOOT_SERVICES_CODE &&
 388                     md->type != EFI_BOOT_SERVICES_DATA)
 389                         continue;
 390                 /* Only reserve where possible:
 391                  * - Not within any already allocated areas
 392                  * - Not over any memory area (really needed, if above?)
 393                  * - Not within any part of the kernel
 394                  * - Not the bios reserved area
 395                 */
 396                 if ((start+size >= virt_to_phys(_text)
 397                                 && start <= virt_to_phys(_end)) ||
 398                         !e820_all_mapped(start, start+size, E820_RAM) ||
 399                         memblock_x86_check_reserved_size(&start, &size,
 400                                                         1<<EFI_PAGE_SHIFT)) {
 401                         /* Could not reserve, skip it */
 402                         md->num_pages = 0;
 403                         memblock_dbg(PFX "Could not reserve boot range "
 404                                         "[0x%010llx-0x%010llx]\n",
 405                                                 start, start+size-1);
 406                 } else
 407                         memblock_x86_reserve_range(start, start+size,
 408                                                         "EFI Boot");
 409         }
 410 }
 411
 412 static void __init efi_free_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                 unsigned long long start = md->phys_addr;
 419                 unsigned long long 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
 425                 /* Could not reserve boot area */
 426                 if (!size)
 427                         continue;
 428
 429                 free_bootmem_late(start, size);
 430         }
 431 }
 432
 433 void __init efi_init(void)
 434 {
 435         efi_config_table_t *config_tables;
 436         efi_runtime_services_t *runtime;
 437         efi_char16_t *c16;
 438         char vendor[100] = "unknown";
 439         int i = 0;
 440         void *tmp;
 441
 442 #ifdef CONFIG_X86_32
 443         efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
 444 #else
 445         efi_phys.systab = (efi_system_table_t *)
 446                 (boot_params.efi_info.efi_systab |
 447                  ((__u64)boot_params.efi_info.efi_systab_hi<<32));
 448 #endif
 449
 450         efi.systab = early_ioremap((unsigned long)efi_phys.systab,
 451                                    sizeof(efi_system_table_t));
 452         if (efi.systab == NULL)
 453                 printk(KERN_ERR "Couldn't map the EFI system table!\n");
 454         memcpy(&efi_systab, efi.systab, sizeof(efi_system_table_t));
 455         early_iounmap(efi.systab, sizeof(efi_system_table_t));
 456         efi.systab = &efi_systab;
 457
 458         /*
 459          * Verify the EFI Table
 460          */
 461         if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 462                 printk(KERN_ERR "EFI system table signature incorrect!\n");
 463         if ((efi.systab->hdr.revision >> 16) == 0)
 464                 printk(KERN_ERR "Warning: EFI system table version "
 465                        "%d.%02d, expected 1.00 or greater!\n",
 466                        efi.systab->hdr.revision >> 16,
 467                        efi.systab->hdr.revision & 0xffff);
 468
 469         /*
 470          * Show what we know for posterity
 471          */
 472         c16 = tmp = early_ioremap(efi.systab->fw_vendor, 2);
 473         if (c16) {
 474                 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
 475                         vendor[i] = *c16++;
 476                 vendor[i] = '\0';
 477         } else
 478                 printk(KERN_ERR PFX "Could not map the firmware vendor!\n");
 479         early_iounmap(tmp, 2);
 480
 481         printk(KERN_INFO "EFI v%u.%.02u by %s\n",
 482                efi.systab->hdr.revision >> 16,
 483                efi.systab->hdr.revision & 0xffff, vendor);
 484
 485         /*
 486          * Let's see what config tables the firmware passed to us.
 487          */
 488         config_tables = early_ioremap(
 489                 efi.systab->tables,
 490                 efi.systab->nr_tables * sizeof(efi_config_table_t));
 491         if (config_tables == NULL)
 492                 printk(KERN_ERR "Could not map EFI Configuration Table!\n");
 493
 494         printk(KERN_INFO);
 495         for (i = 0; i < efi.systab->nr_tables; i++) {
 496                 if (!efi_guidcmp(config_tables[i].guid, MPS_TABLE_GUID)) {
 497                         efi.mps = config_tables[i].table;
 498                         printk(" MPS=0x%lx ", config_tables[i].table);
 499                 } else if (!efi_guidcmp(config_tables[i].guid,
 500                                         ACPI_20_TABLE_GUID)) {
 501                         efi.acpi20 = config_tables[i].table;
 502                         printk(" ACPI 2.0=0x%lx ", config_tables[i].table);
 503                 } else if (!efi_guidcmp(config_tables[i].guid,
 504                                         ACPI_TABLE_GUID)) {
 505                         efi.acpi = config_tables[i].table;
 506                         printk(" ACPI=0x%lx ", config_tables[i].table);
 507                 } else if (!efi_guidcmp(config_tables[i].guid,
 508                                         SMBIOS_TABLE_GUID)) {
 509                         efi.smbios = config_tables[i].table;
 510                         printk(" SMBIOS=0x%lx ", config_tables[i].table);
 511 #ifdef CONFIG_X86_UV
 512                 } else if (!efi_guidcmp(config_tables[i].guid,
 513                                         UV_SYSTEM_TABLE_GUID)) {
 514                         efi.uv_systab = config_tables[i].table;
 515                         printk(" UVsystab=0x%lx ", config_tables[i].table);
 516 #endif
 517                 } else if (!efi_guidcmp(config_tables[i].guid,
 518                                         HCDP_TABLE_GUID)) {
 519                         efi.hcdp = config_tables[i].table;
 520                         printk(" HCDP=0x%lx ", config_tables[i].table);
 521                 } else if (!efi_guidcmp(config_tables[i].guid,
 522                                         UGA_IO_PROTOCOL_GUID)) {
 523                         efi.uga = config_tables[i].table;
 524                         printk(" UGA=0x%lx ", config_tables[i].table);
 525                 }
 526         }
 527         printk("\n");
 528         early_iounmap(config_tables,
 529                           efi.systab->nr_tables * sizeof(efi_config_table_t));
 530
 531         /*
 532          * Check out the runtime services table. We need to map
 533          * the runtime services table so that we can grab the physical
 534          * address of several of the EFI runtime functions, needed to
 535          * set the firmware into virtual mode.
 536          */
 537         runtime = early_ioremap((unsigned long)efi.systab->runtime,
 538                                 sizeof(efi_runtime_services_t));
 539         if (runtime != NULL) {
 540                 /*
 541                  * We will only need *early* access to the following
 542                  * two EFI runtime services before set_virtual_address_map
 543                  * is invoked.
 544                  */
 545                 efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
 546                 efi_phys.set_virtual_address_map =
 547                         (efi_set_virtual_address_map_t *)
 548                         runtime->set_virtual_address_map;
 549                 /*
 550                  * Make efi_get_time can be called before entering
 551                  * virtual mode.
 552                  */
 553                 efi.get_time = phys_efi_get_time;
 554         } else
 555                 printk(KERN_ERR "Could not map the EFI runtime service "
 556                        "table!\n");
 557         early_iounmap(runtime, sizeof(efi_runtime_services_t));
 558
 559         /* Map the EFI memory map */
 560         memmap.map = early_ioremap((unsigned long)memmap.phys_map,
 561                                    memmap.nr_map * memmap.desc_size);
 562         if (memmap.map == NULL)
 563                 printk(KERN_ERR "Could not map the EFI memory map!\n");
 564         memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
 565
 566         if (memmap.desc_size != sizeof(efi_memory_desc_t))
 567                 printk(KERN_WARNING
 568                   "Kernel-defined memdesc doesn't match the one from EFI!\n");
 569
 570         if (add_efi_memmap)
 571                 do_add_efi_memmap();
 572
 573 #ifdef CONFIG_X86_32
 574         x86_platform.get_wallclock = efi_get_time;
 575         x86_platform.set_wallclock = efi_set_rtc_mmss;
 576 #endif
 577
 578 #if EFI_DEBUG
 579         print_efi_memmap();
 580 #endif
 581 }
 582
 583 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
 584 {
 585         u64 addr, npages;
 586
 587         addr = md->virt_addr;
 588         npages = md->num_pages;
 589
 590         memrange_efi_to_native(&addr, &npages);
 591
 592         if (executable)
 593                 set_memory_x(addr, npages);
 594         else
 595                 set_memory_nx(addr, npages);
 596 }
 597
 598 static void __init runtime_code_page_mkexec(void)
 599 {
 600         efi_memory_desc_t *md;
 601         void *p;
 602
 603         /* Make EFI runtime service code area executable */
 604         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 605                 md = p;
 606
 607                 if (md->type != EFI_RUNTIME_SERVICES_CODE)
 608                         continue;
 609
 610                 efi_set_executable(md, true);
 611         }
 612 }
 613
 614 /*
 615  * This function will switch the EFI runtime services to virtual mode.
 616  * Essentially, look through the EFI memmap and map every region that
 617  * has the runtime attribute bit set in its memory descriptor and update
 618  * that memory descriptor with the virtual address obtained from ioremap().
 619  * This enables the runtime services to be called without having to
 620  * thunk back into physical mode for every invocation.
 621  */
 622 void __init efi_enter_virtual_mode(void)
 623 {
 624         efi_memory_desc_t *md, *prev_md = NULL;
 625         efi_status_t status;
 626         unsigned long size;
 627         u64 end, systab, addr, npages, end_pfn;
 628         void *p, *va, *new_memmap = NULL;
 629         int count = 0;
 630
 631         efi.systab = NULL;
 632
 633         /* Merge contiguous regions of the same type and attribute */
 634         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 635                 u64 prev_size;
 636                 md = p;
 637
 638                 if (!prev_md) {
 639                         prev_md = md;
 640                         continue;
 641                 }
 642
 643                 if (prev_md->type != md->type ||
 644                     prev_md->attribute != md->attribute) {
 645                         prev_md = md;
 646                         continue;
 647                 }
 648
 649                 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
 650
 651                 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
 652                         prev_md->num_pages += md->num_pages;
 653                         md->type = EFI_RESERVED_TYPE;
 654                         md->attribute = 0;
 655                         continue;
 656                 }
 657                 prev_md = md;
 658         }
 659
 660         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 661                 md = p;
 662                 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
 663                     md->type != EFI_BOOT_SERVICES_CODE &&
 664                     md->type != EFI_BOOT_SERVICES_DATA)
 665                         continue;
 666
 667                 size = md->num_pages << EFI_PAGE_SHIFT;
 668                 end = md->phys_addr + size;
 669
 670                 end_pfn = PFN_UP(end);
 671                 if (end_pfn <= max_low_pfn_mapped
 672                     || (end_pfn > (1UL << (32 - PAGE_SHIFT))
 673                         && end_pfn <= max_pfn_mapped))
 674                         va = __va(md->phys_addr);
 675                 else
 676                         va = efi_ioremap(md->phys_addr, size, md->type);
 677
 678                 md->virt_addr = (u64) (unsigned long) va;
 679
 680                 if (!va) {
 681                         printk(KERN_ERR PFX "ioremap of 0x%llX failed!\n",
 682                                (unsigned long long)md->phys_addr);
 683                         continue;
 684                 }
 685
 686                 if (!(md->attribute & EFI_MEMORY_WB)) {
 687                         addr = md->virt_addr;
 688                         npages = md->num_pages;
 689                         memrange_efi_to_native(&addr, &npages);
 690                         set_memory_uc(addr, npages);
 691                 }
 692
 693                 systab = (u64) (unsigned long) efi_phys.systab;
 694                 if (md->phys_addr <= systab && systab < end) {
 695                         systab += md->virt_addr - md->phys_addr;
 696                         efi.systab = (efi_system_table_t *) (unsigned long) systab;
 697                 }
 698                 new_memmap = krealloc(new_memmap,
 699                                       (count + 1) * memmap.desc_size,
 700                                       GFP_KERNEL);
 701                 memcpy(new_memmap + (count * memmap.desc_size), md,
 702                        memmap.desc_size);
 703                 count++;
 704         }
 705
 706         BUG_ON(!efi.systab);
 707
 708         status = phys_efi_set_virtual_address_map(
 709                 memmap.desc_size * count,
 710                 memmap.desc_size,
 711                 memmap.desc_version,
 712                 (efi_memory_desc_t *)__pa(new_memmap));
 713
 714         if (status != EFI_SUCCESS) {
 715                 printk(KERN_ALERT "Unable to switch EFI into virtual mode "
 716                        "(status=%lx)!\n", status);
 717                 panic("EFI call to SetVirtualAddressMap() failed!");
 718         }
 719
 720         /*
 721          * Thankfully, it does seem that no runtime services other than
 722          * SetVirtualAddressMap() will touch boot services code, so we can
 723          * get rid of it all at this point
 724          */
 725         efi_free_boot_services();
 726
 727         /*
 728          * Now that EFI is in virtual mode, update the function
 729          * pointers in the runtime service table to the new virtual addresses.
 730          *
 731          * Call EFI services through wrapper functions.
 732          */
 733         efi.get_time = virt_efi_get_time;
 734         efi.set_time = virt_efi_set_time;
 735         efi.get_wakeup_time = virt_efi_get_wakeup_time;
 736         efi.set_wakeup_time = virt_efi_set_wakeup_time;
 737         efi.get_variable = virt_efi_get_variable;
 738         efi.get_next_variable = virt_efi_get_next_variable;
 739         efi.set_variable = virt_efi_set_variable;
 740         efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
 741         efi.reset_system = virt_efi_reset_system;
 742         efi.set_virtual_address_map = NULL;
 743         efi.query_variable_info = virt_efi_query_variable_info;
 744         efi.update_capsule = virt_efi_update_capsule;
 745         efi.query_capsule_caps = virt_efi_query_capsule_caps;
 746         if (__supported_pte_mask & _PAGE_NX)
 747                 runtime_code_page_mkexec();
 748         early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size);
 749         memmap.map = NULL;
 750         kfree(new_memmap);
 751 }
 752
 753 /*
 754  * Convenience functions to obtain memory types and attributes
 755  */
 756 u32 efi_mem_type(unsigned long phys_addr)
 757 {
 758         efi_memory_desc_t *md;
 759         void *p;
 760
 761         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 762                 md = p;
 763                 if ((md->phys_addr <= phys_addr) &&
 764                     (phys_addr < (md->phys_addr +
 765                                   (md->num_pages << EFI_PAGE_SHIFT))))
 766                         return md->type;
 767         }
 768         return 0;
 769 }
 770
 771 u64 efi_mem_attributes(unsigned long phys_addr)
 772 {
 773         efi_memory_desc_t *md;
 774         void *p;
 775
 776         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 777                 md = p;
 778                 if ((md->phys_addr <= phys_addr) &&
 779                     (phys_addr < (md->phys_addr +
 780                                   (md->num_pages << EFI_PAGE_SHIFT))))
 781                         return md->attribute;
 782         }
 783         return 0;
 784 }