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/export.h>
  33 #include <linux/bootmem.h>
  34 #include <linux/memblock.h>
  35 #include <linux/spinlock.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/time.h>
  38 #include <linux/io.h>
  39 #include <linux/reboot.h>
  40 #include <linux/bcd.h>
  41
  42 #include <asm/setup.h>
  43 #include <asm/efi.h>
  44 #include <asm/time.h>
  45 #include <asm/cacheflush.h>
  46 #include <asm/tlbflush.h>
  47 #include <asm/x86_init.h>
  48
  49 #define EFI_DEBUG       1
  50 #define PFX             "EFI: "
  51
  52 int efi_enabled;
  53 EXPORT_SYMBOL(efi_enabled);
  54
  55 struct efi __read_mostly efi = {
  56         .mps        = EFI_INVALID_TABLE_ADDR,
  57         .acpi       = EFI_INVALID_TABLE_ADDR,
  58         .acpi20     = EFI_INVALID_TABLE_ADDR,
  59         .smbios     = EFI_INVALID_TABLE_ADDR,
  60         .sal_systab = EFI_INVALID_TABLE_ADDR,
  61         .boot_info  = EFI_INVALID_TABLE_ADDR,
  62         .hcdp       = EFI_INVALID_TABLE_ADDR,
  63         .uga        = EFI_INVALID_TABLE_ADDR,
  64         .uv_systab  = EFI_INVALID_TABLE_ADDR,
  65 };
  66 EXPORT_SYMBOL(efi);
  67
  68 struct efi_memory_map memmap;
  69
  70 static struct efi efi_phys __initdata;
  71 static efi_system_table_t efi_systab __initdata;
  72
  73 static int __init setup_noefi(char *arg)
  74 {
  75         efi_enabled = 0;
  76         return 0;
  77 }
  78 early_param("noefi", setup_noefi);
  79
  80 int add_efi_memmap;
  81 EXPORT_SYMBOL(add_efi_memmap);
  82
  83 static int __init setup_add_efi_memmap(char *arg)
  84 {
  85         add_efi_memmap = 1;
  86         return 0;
  87 }
  88 early_param("add_efi_memmap", setup_add_efi_memmap);
  89
  90
  91 static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
  92 {
  93         unsigned long flags;
  94         efi_status_t status;
  95
  96         spin_lock_irqsave(&rtc_lock, flags);
  97         status = efi_call_virt2(get_time, tm, tc);
  98         spin_unlock_irqrestore(&rtc_lock, flags);
  99         return status;
 100 }
 101
 102 static efi_status_t virt_efi_set_time(efi_time_t *tm)
 103 {
 104         unsigned long flags;
 105         efi_status_t status;
 106
 107         spin_lock_irqsave(&rtc_lock, flags);
 108         status = efi_call_virt1(set_time, tm);
 109         spin_unlock_irqrestore(&rtc_lock, flags);
 110         return status;
 111 }
 112
 113 static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
 114                                              efi_bool_t *pending,
 115                                              efi_time_t *tm)
 116 {
 117         unsigned long flags;
 118         efi_status_t status;
 119
 120         spin_lock_irqsave(&rtc_lock, flags);
 121         status = efi_call_virt3(get_wakeup_time,
 122                                 enabled, pending, tm);
 123         spin_unlock_irqrestore(&rtc_lock, flags);
 124         return status;
 125 }
 126
 127 static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 128 {
 129         unsigned long flags;
 130         efi_status_t status;
 131
 132         spin_lock_irqsave(&rtc_lock, flags);
 133         status = efi_call_virt2(set_wakeup_time,
 134                                 enabled, tm);
 135         spin_unlock_irqrestore(&rtc_lock, flags);
 136         return status;
 137 }
 138
 139 static efi_status_t virt_efi_get_variable(efi_char16_t *name,
 140                                           efi_guid_t *vendor,
 141                                           u32 *attr,
 142                                           unsigned long *data_size,
 143                                           void *data)
 144 {
 145         return efi_call_virt5(get_variable,
 146                               name, vendor, attr,
 147                               data_size, data);
 148 }
 149
 150 static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
 151                                                efi_char16_t *name,
 152                                                efi_guid_t *vendor)
 153 {
 154         return efi_call_virt3(get_next_variable,
 155                               name_size, name, vendor);
 156 }
 157
 158 static efi_status_t virt_efi_set_variable(efi_char16_t *name,
 159                                           efi_guid_t *vendor,
 160                                           u32 attr,
 161                                           unsigned long data_size,
 162                                           void *data)
 163 {
 164         return efi_call_virt5(set_variable,
 165                               name, vendor, attr,
 166                               data_size, data);
 167 }
 168
 169 static efi_status_t virt_efi_query_variable_info(u32 attr,
 170                                                  u64 *storage_space,
 171                                                  u64 *remaining_space,
 172                                                  u64 *max_variable_size)
 173 {
 174         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 175                 return EFI_UNSUPPORTED;
 176
 177         return efi_call_virt4(query_variable_info, attr, storage_space,
 178                               remaining_space, max_variable_size);
 179 }
 180
 181 static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
 182 {
 183         return efi_call_virt1(get_next_high_mono_count, count);
 184 }
 185
 186 static void virt_efi_reset_system(int reset_type,
 187                                   efi_status_t status,
 188                                   unsigned long data_size,
 189                                   efi_char16_t *data)
 190 {
 191         efi_call_virt4(reset_system, reset_type, status,
 192                        data_size, data);
 193 }
 194
 195 static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
 196                                             unsigned long count,
 197                                             unsigned long sg_list)
 198 {
 199         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 200                 return EFI_UNSUPPORTED;
 201
 202         return efi_call_virt3(update_capsule, capsules, count, sg_list);
 203 }
 204
 205 static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
 206                                                 unsigned long count,
 207                                                 u64 *max_size,
 208                                                 int *reset_type)
 209 {
 210         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 211                 return EFI_UNSUPPORTED;
 212
 213         return efi_call_virt4(query_capsule_caps, capsules, count, max_size,
 214                               reset_type);
 215 }
 216
 217 static efi_status_t __init phys_efi_set_virtual_address_map(
 218         unsigned long memory_map_size,
 219         unsigned long descriptor_size,
 220         u32 descriptor_version,
 221         efi_memory_desc_t *virtual_map)
 222 {
 223         efi_status_t status;
 224
 225         efi_call_phys_prelog();
 226         status = efi_call_phys4(efi_phys.set_virtual_address_map,
 227                                 memory_map_size, descriptor_size,
 228                                 descriptor_version, virtual_map);
 229         efi_call_phys_epilog();
 230         return status;
 231 }
 232
 233 static efi_status_t __init phys_efi_get_time(efi_time_t *tm,
 234                                              efi_time_cap_t *tc)
 235 {
 236         unsigned long flags;
 237         efi_status_t status;
 238
 239         spin_lock_irqsave(&rtc_lock, flags);
 240         efi_call_phys_prelog();
 241         status = efi_call_phys2(efi_phys.get_time, tm, tc);
 242         efi_call_phys_epilog();
 243         spin_unlock_irqrestore(&rtc_lock, flags);
 244         return status;
 245 }
 246
 247 int efi_set_rtc_mmss(unsigned long nowtime)
 248 {
 249         int real_seconds, real_minutes;
 250         efi_status_t    status;
 251         efi_time_t      eft;
 252         efi_time_cap_t  cap;
 253
 254         status = efi.get_time(&eft, &cap);
 255         if (status != EFI_SUCCESS) {
 256                 printk(KERN_ERR "Oops: efitime: can't read time!\n");
 257                 return -1;
 258         }
 259
 260         real_seconds = nowtime % 60;
 261         real_minutes = nowtime / 60;
 262         if (((abs(real_minutes - eft.minute) + 15)/30) & 1)
 263                 real_minutes += 30;
 264         real_minutes %= 60;
 265         eft.minute = real_minutes;
 266         eft.second = real_seconds;
 267
 268         status = efi.set_time(&eft);
 269         if (status != EFI_SUCCESS) {
 270                 printk(KERN_ERR "Oops: efitime: can't write time!\n");
 271                 return -1;
 272         }
 273         return 0;
 274 }
 275
 276 unsigned long efi_get_time(void)
 277 {
 278         efi_status_t status;
 279         efi_time_t eft;
 280         efi_time_cap_t cap;
 281
 282         status = efi.get_time(&eft, &cap);
 283         if (status != EFI_SUCCESS)
 284                 printk(KERN_ERR "Oops: efitime: can't read time!\n");
 285
 286         return mktime(eft.year, eft.month, eft.day, eft.hour,
 287                       eft.minute, eft.second);
 288 }
 289
 290 /*
 291  * Tell the kernel about the EFI memory map.  This might include
 292  * more than the max 128 entries that can fit in the e820 legacy
 293  * (zeropage) memory map.
 294  */
 295
 296 static void __init do_add_efi_memmap(void)
 297 {
 298         void *p;
 299
 300         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 301                 efi_memory_desc_t *md = p;
 302                 unsigned long long start = md->phys_addr;
 303                 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
 304                 int e820_type;
 305
 306                 switch (md->type) {
 307                 case EFI_LOADER_CODE:
 308                 case EFI_LOADER_DATA:
 309                 case EFI_BOOT_SERVICES_CODE:
 310                 case EFI_BOOT_SERVICES_DATA:
 311                 case EFI_CONVENTIONAL_MEMORY:
 312                         if (md->attribute & EFI_MEMORY_WB)
 313                                 e820_type = E820_RAM;
 314                         else
 315                                 e820_type = E820_RESERVED;
 316                         break;
 317                 case EFI_ACPI_RECLAIM_MEMORY:
 318                         e820_type = E820_ACPI;
 319                         break;
 320                 case EFI_ACPI_MEMORY_NVS:
 321                         e820_type = E820_NVS;
 322                         break;
 323                 case EFI_UNUSABLE_MEMORY:
 324                         e820_type = E820_UNUSABLE;
 325                         break;
 326                 default:
 327                         /*
 328                          * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
 329                          * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
 330                          * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
 331                          */
 332                         e820_type = E820_RESERVED;
 333                         break;
 334                 }
 335                 e820_add_region(start, size, e820_type);
 336         }
 337         sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 338 }
 339
 340 void __init efi_memblock_x86_reserve_range(void)
 341 {
 342         unsigned long pmap;
 343
 344 #ifdef CONFIG_X86_32
 345         pmap = boot_params.efi_info.efi_memmap;
 346 #else
 347         pmap = (boot_params.efi_info.efi_memmap |
 348                 ((__u64)boot_params.efi_info.efi_memmap_hi<<32));
 349 #endif
 350         memmap.phys_map = (void *)pmap;
 351         memmap.nr_map = boot_params.efi_info.efi_memmap_size /
 352                 boot_params.efi_info.efi_memdesc_size;
 353         memmap.desc_version = boot_params.efi_info.efi_memdesc_version;
 354         memmap.desc_size = boot_params.efi_info.efi_memdesc_size;
 355         memblock_reserve(pmap, memmap.nr_map * memmap.desc_size);
 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_is_region_reserved(start, size)) {
 400                         /* Could not reserve, skip it */
 401                         md->num_pages = 0;
 402                         memblock_dbg(PFX "Could not reserve boot range "
 403                                         "[0x%010llx-0x%010llx]\n",
 404                                                 start, start+size-1);
 405                 } else
 406                         memblock_reserve(start, size);
 407         }
 408 }
 409
 410 static void __init efi_free_boot_services(void)
 411 {
 412         void *p;
 413
 414         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 415                 efi_memory_desc_t *md = p;
 416                 unsigned long long start = md->phys_addr;
 417                 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
 418
 419                 if (md->type != EFI_BOOT_SERVICES_CODE &&
 420                     md->type != EFI_BOOT_SERVICES_DATA)
 421                         continue;
 422
 423                 /* Could not reserve boot area */
 424                 if (!size)
 425                         continue;
 426
 427                 free_bootmem_late(start, size);
 428         }
 429 }
 430
 431 void __init efi_init(void)
 432 {
 433         efi_config_table_t *config_tables;
 434         efi_runtime_services_t *runtime;
 435         efi_char16_t *c16;
 436         char vendor[100] = "unknown";
 437         int i = 0;
 438         void *tmp;
 439
 440 #ifdef CONFIG_X86_32
 441         efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
 442 #else
 443         efi_phys.systab = (efi_system_table_t *)
 444                 (boot_params.efi_info.efi_systab |
 445                  ((__u64)boot_params.efi_info.efi_systab_hi<<32));
 446 #endif
 447
 448         efi.systab = early_ioremap((unsigned long)efi_phys.systab,
 449                                    sizeof(efi_system_table_t));
 450         if (efi.systab == NULL)
 451                 printk(KERN_ERR "Couldn't map the EFI system table!\n");
 452         memcpy(&efi_systab, efi.systab, sizeof(efi_system_table_t));
 453         early_iounmap(efi.systab, sizeof(efi_system_table_t));
 454         efi.systab = &efi_systab;
 455
 456         /*
 457          * Verify the EFI Table
 458          */
 459         if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 460                 printk(KERN_ERR "EFI system table signature incorrect!\n");
 461         if ((efi.systab->hdr.revision >> 16) == 0)
 462                 printk(KERN_ERR "Warning: EFI system table version "
 463                        "%d.%02d, expected 1.00 or greater!\n",
 464                        efi.systab->hdr.revision >> 16,
 465                        efi.systab->hdr.revision & 0xffff);
 466
 467         /*
 468          * Show what we know for posterity
 469          */
 470         c16 = tmp = early_ioremap(efi.systab->fw_vendor, 2);
 471         if (c16) {
 472                 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
 473                         vendor[i] = *c16++;
 474                 vendor[i] = '\0';
 475         } else
 476                 printk(KERN_ERR PFX "Could not map the firmware vendor!\n");
 477         early_iounmap(tmp, 2);
 478
 479         printk(KERN_INFO "EFI v%u.%.02u by %s\n",
 480                efi.systab->hdr.revision >> 16,
 481                efi.systab->hdr.revision & 0xffff, vendor);
 482
 483         /*
 484          * Let's see what config tables the firmware passed to us.
 485          */
 486         config_tables = early_ioremap(
 487                 efi.systab->tables,
 488                 efi.systab->nr_tables * sizeof(efi_config_table_t));
 489         if (config_tables == NULL)
 490                 printk(KERN_ERR "Could not map EFI Configuration Table!\n");
 491
 492         printk(KERN_INFO);
 493         for (i = 0; i < efi.systab->nr_tables; i++) {
 494                 if (!efi_guidcmp(config_tables[i].guid, MPS_TABLE_GUID)) {
 495                         efi.mps = config_tables[i].table;
 496                         printk(" MPS=0x%lx ", config_tables[i].table);
 497                 } else if (!efi_guidcmp(config_tables[i].guid,
 498                                         ACPI_20_TABLE_GUID)) {
 499                         efi.acpi20 = config_tables[i].table;
 500                         printk(" ACPI 2.0=0x%lx ", config_tables[i].table);
 501                 } else if (!efi_guidcmp(config_tables[i].guid,
 502                                         ACPI_TABLE_GUID)) {
 503                         efi.acpi = config_tables[i].table;
 504                         printk(" ACPI=0x%lx ", config_tables[i].table);
 505                 } else if (!efi_guidcmp(config_tables[i].guid,
 506                                         SMBIOS_TABLE_GUID)) {
 507                         efi.smbios = config_tables[i].table;
 508                         printk(" SMBIOS=0x%lx ", config_tables[i].table);
 509 #ifdef CONFIG_X86_UV
 510                 } else if (!efi_guidcmp(config_tables[i].guid,
 511                                         UV_SYSTEM_TABLE_GUID)) {
 512                         efi.uv_systab = config_tables[i].table;
 513                         printk(" UVsystab=0x%lx ", config_tables[i].table);
 514 #endif
 515                 } else if (!efi_guidcmp(config_tables[i].guid,
 516                                         HCDP_TABLE_GUID)) {
 517                         efi.hcdp = config_tables[i].table;
 518                         printk(" HCDP=0x%lx ", config_tables[i].table);
 519                 } else if (!efi_guidcmp(config_tables[i].guid,
 520                                         UGA_IO_PROTOCOL_GUID)) {
 521                         efi.uga = config_tables[i].table;
 522                         printk(" UGA=0x%lx ", config_tables[i].table);
 523                 }
 524         }
 525         printk("\n");
 526         early_iounmap(config_tables,
 527                           efi.systab->nr_tables * sizeof(efi_config_table_t));
 528
 529         /*
 530          * Check out the runtime services table. We need to map
 531          * the runtime services table so that we can grab the physical
 532          * address of several of the EFI runtime functions, needed to
 533          * set the firmware into virtual mode.
 534          */
 535         runtime = early_ioremap((unsigned long)efi.systab->runtime,
 536                                 sizeof(efi_runtime_services_t));
 537         if (runtime != NULL) {
 538                 /*
 539                  * We will only need *early* access to the following
 540                  * two EFI runtime services before set_virtual_address_map
 541                  * is invoked.
 542                  */
 543                 efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
 544                 efi_phys.set_virtual_address_map =
 545                         (efi_set_virtual_address_map_t *)
 546                         runtime->set_virtual_address_map;
 547                 /*
 548                  * Make efi_get_time can be called before entering
 549                  * virtual mode.
 550                  */
 551                 efi.get_time = phys_efi_get_time;
 552         } else
 553                 printk(KERN_ERR "Could not map the EFI runtime service "
 554                        "table!\n");
 555         early_iounmap(runtime, sizeof(efi_runtime_services_t));
 556
 557         /* Map the EFI memory map */
 558         memmap.map = early_ioremap((unsigned long)memmap.phys_map,
 559                                    memmap.nr_map * memmap.desc_size);
 560         if (memmap.map == NULL)
 561                 printk(KERN_ERR "Could not map the EFI memory map!\n");
 562         memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
 563
 564         if (memmap.desc_size != sizeof(efi_memory_desc_t))
 565                 printk(KERN_WARNING
 566                   "Kernel-defined memdesc doesn't match the one from EFI!\n");
 567
 568         if (add_efi_memmap)
 569                 do_add_efi_memmap();
 570
 571 #ifdef CONFIG_X86_32
 572         x86_platform.get_wallclock = efi_get_time;
 573         x86_platform.set_wallclock = efi_set_rtc_mmss;
 574 #endif
 575
 576 #if EFI_DEBUG
 577         print_efi_memmap();
 578 #endif
 579 }
 580
 581 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
 582 {
 583         u64 addr, npages;
 584
 585         addr = md->virt_addr;
 586         npages = md->num_pages;
 587
 588         memrange_efi_to_native(&addr, &npages);
 589
 590         if (executable)
 591                 set_memory_x(addr, npages);
 592         else
 593                 set_memory_nx(addr, npages);
 594 }
 595
 596 static void __init runtime_code_page_mkexec(void)
 597 {
 598         efi_memory_desc_t *md;
 599         void *p;
 600
 601         /* Make EFI runtime service code area executable */
 602         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 603                 md = p;
 604
 605                 if (md->type != EFI_RUNTIME_SERVICES_CODE)
 606                         continue;
 607
 608                 efi_set_executable(md, true);
 609         }
 610 }
 611
 612 /*
 613  * This function will switch the EFI runtime services to virtual mode.
 614  * Essentially, look through the EFI memmap and map every region that
 615  * has the runtime attribute bit set in its memory descriptor and update
 616  * that memory descriptor with the virtual address obtained from ioremap().
 617  * This enables the runtime services to be called without having to
 618  * thunk back into physical mode for every invocation.
 619  */
 620 void __init efi_enter_virtual_mode(void)
 621 {
 622         efi_memory_desc_t *md, *prev_md = NULL;
 623         efi_status_t status;
 624         unsigned long size;
 625         u64 end, systab, addr, npages, end_pfn;
 626         void *p, *va, *new_memmap = NULL;
 627         int count = 0;
 628
 629         efi.systab = NULL;
 630
 631         /* Merge contiguous regions of the same type and attribute */
 632         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 633                 u64 prev_size;
 634                 md = p;
 635
 636                 if (!prev_md) {
 637                         prev_md = md;
 638                         continue;
 639                 }
 640
 641                 if (prev_md->type != md->type ||
 642                     prev_md->attribute != md->attribute) {
 643                         prev_md = md;
 644                         continue;
 645                 }
 646
 647                 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
 648
 649                 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
 650                         prev_md->num_pages += md->num_pages;
 651                         md->type = EFI_RESERVED_TYPE;
 652                         md->attribute = 0;
 653                         continue;
 654                 }
 655                 prev_md = md;
 656         }
 657
 658         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 659                 md = p;
 660                 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
 661                     md->type != EFI_BOOT_SERVICES_CODE &&
 662                     md->type != EFI_BOOT_SERVICES_DATA)
 663                         continue;
 664
 665                 size = md->num_pages << EFI_PAGE_SHIFT;
 666                 end = md->phys_addr + size;
 667
 668                 end_pfn = PFN_UP(end);
 669                 if (end_pfn <= max_low_pfn_mapped
 670                     || (end_pfn > (1UL << (32 - PAGE_SHIFT))
 671                         && end_pfn <= max_pfn_mapped))
 672                         va = __va(md->phys_addr);
 673                 else
 674                         va = efi_ioremap(md->phys_addr, size, md->type);
 675
 676                 md->virt_addr = (u64) (unsigned long) va;
 677
 678                 if (!va) {
 679                         printk(KERN_ERR PFX "ioremap of 0x%llX failed!\n",
 680                                (unsigned long long)md->phys_addr);
 681                         continue;
 682                 }
 683
 684                 if (!(md->attribute & EFI_MEMORY_WB)) {
 685                         addr = md->virt_addr;
 686                         npages = md->num_pages;
 687                         memrange_efi_to_native(&addr, &npages);
 688                         set_memory_uc(addr, npages);
 689                 }
 690
 691                 systab = (u64) (unsigned long) efi_phys.systab;
 692                 if (md->phys_addr <= systab && systab < end) {
 693                         systab += md->virt_addr - md->phys_addr;
 694                         efi.systab = (efi_system_table_t *) (unsigned long) systab;
 695                 }
 696                 new_memmap = krealloc(new_memmap,
 697                                       (count + 1) * memmap.desc_size,
 698                                       GFP_KERNEL);
 699                 memcpy(new_memmap + (count * memmap.desc_size), md,
 700                        memmap.desc_size);
 701                 count++;
 702         }
 703
 704         BUG_ON(!efi.systab);
 705
 706         status = phys_efi_set_virtual_address_map(
 707                 memmap.desc_size * count,
 708                 memmap.desc_size,
 709                 memmap.desc_version,
 710                 (efi_memory_desc_t *)__pa(new_memmap));
 711
 712         if (status != EFI_SUCCESS) {
 713                 printk(KERN_ALERT "Unable to switch EFI into virtual mode "
 714                        "(status=%lx)!\n", status);
 715                 panic("EFI call to SetVirtualAddressMap() failed!");
 716         }
 717
 718         /*
 719          * Thankfully, it does seem that no runtime services other than
 720          * SetVirtualAddressMap() will touch boot services code, so we can
 721          * get rid of it all at this point
 722          */
 723         efi_free_boot_services();
 724
 725         /*
 726          * Now that EFI is in virtual mode, update the function
 727          * pointers in the runtime service table to the new virtual addresses.
 728          *
 729          * Call EFI services through wrapper functions.
 730          */
 731         efi.get_time = virt_efi_get_time;
 732         efi.set_time = virt_efi_set_time;
 733         efi.get_wakeup_time = virt_efi_get_wakeup_time;
 734         efi.set_wakeup_time = virt_efi_set_wakeup_time;
 735         efi.get_variable = virt_efi_get_variable;
 736         efi.get_next_variable = virt_efi_get_next_variable;
 737         efi.set_variable = virt_efi_set_variable;
 738         efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
 739         efi.reset_system = virt_efi_reset_system;
 740         efi.set_virtual_address_map = NULL;
 741         efi.query_variable_info = virt_efi_query_variable_info;
 742         efi.update_capsule = virt_efi_update_capsule;
 743         efi.query_capsule_caps = virt_efi_query_capsule_caps;
 744         if (__supported_pte_mask & _PAGE_NX)
 745                 runtime_code_page_mkexec();
 746         early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size);
 747         memmap.map = NULL;
 748         kfree(new_memmap);
 749 }
 750
 751 /*
 752  * Convenience functions to obtain memory types and attributes
 753  */
 754 u32 efi_mem_type(unsigned long phys_addr)
 755 {
 756         efi_memory_desc_t *md;
 757         void *p;
 758
 759         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 760                 md = p;
 761                 if ((md->phys_addr <= phys_addr) &&
 762                     (phys_addr < (md->phys_addr +
 763                                   (md->num_pages << EFI_PAGE_SHIFT))))
 764                         return md->type;
 765         }
 766         return 0;
 767 }
 768
 769 u64 efi_mem_attributes(unsigned long phys_addr)
 770 {
 771         efi_memory_desc_t *md;
 772         void *p;
 773
 774         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 775                 md = p;
 776                 if ((md->phys_addr <= phys_addr) &&
 777                     (phys_addr < (md->phys_addr +
 778                                   (md->num_pages << EFI_PAGE_SHIFT))))
 779                         return md->attribute;
 780         }
 781         return 0;
 782 }