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 struct efi_memory_map memmap;
  60
  61 static struct efi efi_phys __initdata;
  62 static efi_system_table_t efi_systab __initdata;
  63
  64 static efi_config_table_type_t arch_tables[] __initdata = {
  65 #ifdef CONFIG_X86_UV
  66         {UV_SYSTEM_TABLE_GUID, "UVsystab", &efi.uv_systab},
  67 #endif
  68         {NULL_GUID, NULL, NULL},
  69 };
  70
  71 u64 efi_setup;          /* efi setup_data physical address */
  72
  73 static int add_efi_memmap __initdata;
  74 static int __init setup_add_efi_memmap(char *arg)
  75 {
  76         add_efi_memmap = 1;
  77         return 0;
  78 }
  79 early_param("add_efi_memmap", setup_add_efi_memmap);
  80
  81 static efi_status_t __init phys_efi_set_virtual_address_map(
  82         unsigned long memory_map_size,
  83         unsigned long descriptor_size,
  84         u32 descriptor_version,
  85         efi_memory_desc_t *virtual_map)
  86 {
  87         efi_status_t status;
  88         unsigned long flags;
  89         pgd_t *save_pgd;
  90
  91         save_pgd = efi_call_phys_prolog();
  92
  93         /* Disable interrupts around EFI calls: */
  94         local_irq_save(flags);
  95         status = efi_call_phys(efi_phys.set_virtual_address_map,
  96                                memory_map_size, descriptor_size,
  97                                descriptor_version, virtual_map);
  98         local_irq_restore(flags);
  99
 100         efi_call_phys_epilog(save_pgd);
 101
 102         return status;
 103 }
 104
 105 void efi_get_time(struct timespec *now)
 106 {
 107         efi_status_t status;
 108         efi_time_t eft;
 109         efi_time_cap_t cap;
 110
 111         status = efi.get_time(&eft, &cap);
 112         if (status != EFI_SUCCESS)
 113                 pr_err("Oops: efitime: can't read time!\n");
 114
 115         now->tv_sec = mktime(eft.year, eft.month, eft.day, eft.hour,
 116                              eft.minute, eft.second);
 117         now->tv_nsec = 0;
 118 }
 119
 120 void __init efi_find_mirror(void)
 121 {
 122         void *p;
 123         u64 mirror_size = 0, total_size = 0;
 124
 125         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 126                 efi_memory_desc_t *md = p;
 127                 unsigned long long start = md->phys_addr;
 128                 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
 129
 130                 total_size += size;
 131                 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
 132                         memblock_mark_mirror(start, size);
 133                         mirror_size += size;
 134                 }
 135         }
 136         if (mirror_size)
 137                 pr_info("Memory: %lldM/%lldM mirrored memory\n",
 138                         mirror_size>>20, total_size>>20);
 139 }
 140
 141 /*
 142  * Tell the kernel about the EFI memory map.  This might include
 143  * more than the max 128 entries that can fit in the e820 legacy
 144  * (zeropage) memory map.
 145  */
 146
 147 static void __init do_add_efi_memmap(void)
 148 {
 149         void *p;
 150
 151         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 152                 efi_memory_desc_t *md = p;
 153                 unsigned long long start = md->phys_addr;
 154                 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
 155                 int e820_type;
 156
 157                 switch (md->type) {
 158                 case EFI_LOADER_CODE:
 159                 case EFI_LOADER_DATA:
 160                 case EFI_BOOT_SERVICES_CODE:
 161                 case EFI_BOOT_SERVICES_DATA:
 162                 case EFI_CONVENTIONAL_MEMORY:
 163                         if (md->attribute & EFI_MEMORY_WB)
 164                                 e820_type = E820_RAM;
 165                         else
 166                                 e820_type = E820_RESERVED;
 167                         break;
 168                 case EFI_ACPI_RECLAIM_MEMORY:
 169                         e820_type = E820_ACPI;
 170                         break;
 171                 case EFI_ACPI_MEMORY_NVS:
 172                         e820_type = E820_NVS;
 173                         break;
 174                 case EFI_UNUSABLE_MEMORY:
 175                         e820_type = E820_UNUSABLE;
 176                         break;
 177                 case EFI_PERSISTENT_MEMORY:
 178                         e820_type = E820_PMEM;
 179                         break;
 180                 default:
 181                         /*
 182                          * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
 183                          * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
 184                          * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
 185                          */
 186                         e820_type = E820_RESERVED;
 187                         break;
 188                 }
 189                 e820_add_region(start, size, e820_type);
 190         }
 191         sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 192 }
 193
 194 int __init efi_memblock_x86_reserve_range(void)
 195 {
 196         struct efi_info *e = &boot_params.efi_info;
 197         unsigned long pmap;
 198
 199         if (efi_enabled(EFI_PARAVIRT))
 200                 return 0;
 201
 202 #ifdef CONFIG_X86_32
 203         /* Can't handle data above 4GB at this time */
 204         if (e->efi_memmap_hi) {
 205                 pr_err("Memory map is above 4GB, disabling EFI.\n");
 206                 return -EINVAL;
 207         }
 208         pmap =  e->efi_memmap;
 209 #else
 210         pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));
 211 #endif
 212         memmap.phys_map         = (void *)pmap;
 213         memmap.nr_map           = e->efi_memmap_size /
 214                                   e->efi_memdesc_size;
 215         memmap.desc_size        = e->efi_memdesc_size;
 216         memmap.desc_version     = e->efi_memdesc_version;
 217
 218         memblock_reserve(pmap, memmap.nr_map * memmap.desc_size);
 219
 220         efi.memmap = &memmap;
 221
 222         return 0;
 223 }
 224
 225 static void __init print_efi_memmap(void)
 226 {
 227 #ifdef EFI_DEBUG
 228         efi_memory_desc_t *md;
 229         void *p;
 230         int i;
 231
 232         for (p = memmap.map, i = 0;
 233              p < memmap.map_end;
 234              p += memmap.desc_size, i++) {
 235                 char buf[64];
 236
 237                 md = p;
 238                 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx) (%lluMB)\n",
 239                         i, efi_md_typeattr_format(buf, sizeof(buf), md),
 240                         md->phys_addr,
 241                         md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
 242                         (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
 243         }
 244 #endif  /*  EFI_DEBUG  */
 245 }
 246
 247 void __init efi_unmap_memmap(void)
 248 {
 249         clear_bit(EFI_MEMMAP, &efi.flags);
 250         if (memmap.map) {
 251                 early_memunmap(memmap.map, memmap.nr_map * memmap.desc_size);
 252                 memmap.map = NULL;
 253         }
 254 }
 255
 256 static int __init efi_systab_init(void *phys)
 257 {
 258         if (efi_enabled(EFI_64BIT)) {
 259                 efi_system_table_64_t *systab64;
 260                 struct efi_setup_data *data = NULL;
 261                 u64 tmp = 0;
 262
 263                 if (efi_setup) {
 264                         data = early_memremap(efi_setup, sizeof(*data));
 265                         if (!data)
 266                                 return -ENOMEM;
 267                 }
 268                 systab64 = early_memremap((unsigned long)phys,
 269                                          sizeof(*systab64));
 270                 if (systab64 == NULL) {
 271                         pr_err("Couldn't map the system table!\n");
 272                         if (data)
 273                                 early_memunmap(data, sizeof(*data));
 274                         return -ENOMEM;
 275                 }
 276
 277                 efi_systab.hdr = systab64->hdr;
 278                 efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor :
 279                                               systab64->fw_vendor;
 280                 tmp |= data ? data->fw_vendor : systab64->fw_vendor;
 281                 efi_systab.fw_revision = systab64->fw_revision;
 282                 efi_systab.con_in_handle = systab64->con_in_handle;
 283                 tmp |= systab64->con_in_handle;
 284                 efi_systab.con_in = systab64->con_in;
 285                 tmp |= systab64->con_in;
 286                 efi_systab.con_out_handle = systab64->con_out_handle;
 287                 tmp |= systab64->con_out_handle;
 288                 efi_systab.con_out = systab64->con_out;
 289                 tmp |= systab64->con_out;
 290                 efi_systab.stderr_handle = systab64->stderr_handle;
 291                 tmp |= systab64->stderr_handle;
 292                 efi_systab.stderr = systab64->stderr;
 293                 tmp |= systab64->stderr;
 294                 efi_systab.runtime = data ?
 295                                      (void *)(unsigned long)data->runtime :
 296                                      (void *)(unsigned long)systab64->runtime;
 297                 tmp |= data ? data->runtime : systab64->runtime;
 298                 efi_systab.boottime = (void *)(unsigned long)systab64->boottime;
 299                 tmp |= systab64->boottime;
 300                 efi_systab.nr_tables = systab64->nr_tables;
 301                 efi_systab.tables = data ? (unsigned long)data->tables :
 302                                            systab64->tables;
 303                 tmp |= data ? data->tables : systab64->tables;
 304
 305                 early_memunmap(systab64, sizeof(*systab64));
 306                 if (data)
 307                         early_memunmap(data, sizeof(*data));
 308 #ifdef CONFIG_X86_32
 309                 if (tmp >> 32) {
 310                         pr_err("EFI data located above 4GB, disabling EFI.\n");
 311                         return -EINVAL;
 312                 }
 313 #endif
 314         } else {
 315                 efi_system_table_32_t *systab32;
 316
 317                 systab32 = early_memremap((unsigned long)phys,
 318                                          sizeof(*systab32));
 319                 if (systab32 == NULL) {
 320                         pr_err("Couldn't map the system table!\n");
 321                         return -ENOMEM;
 322                 }
 323
 324                 efi_systab.hdr = systab32->hdr;
 325                 efi_systab.fw_vendor = systab32->fw_vendor;
 326                 efi_systab.fw_revision = systab32->fw_revision;
 327                 efi_systab.con_in_handle = systab32->con_in_handle;
 328                 efi_systab.con_in = systab32->con_in;
 329                 efi_systab.con_out_handle = systab32->con_out_handle;
 330                 efi_systab.con_out = systab32->con_out;
 331                 efi_systab.stderr_handle = systab32->stderr_handle;
 332                 efi_systab.stderr = systab32->stderr;
 333                 efi_systab.runtime = (void *)(unsigned long)systab32->runtime;
 334                 efi_systab.boottime = (void *)(unsigned long)systab32->boottime;
 335                 efi_systab.nr_tables = systab32->nr_tables;
 336                 efi_systab.tables = systab32->tables;
 337
 338                 early_memunmap(systab32, sizeof(*systab32));
 339         }
 340
 341         efi.systab = &efi_systab;
 342
 343         /*
 344          * Verify the EFI Table
 345          */
 346         if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
 347                 pr_err("System table signature incorrect!\n");
 348                 return -EINVAL;
 349         }
 350         if ((efi.systab->hdr.revision >> 16) == 0)
 351                 pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n",
 352                        efi.systab->hdr.revision >> 16,
 353                        efi.systab->hdr.revision & 0xffff);
 354
 355         set_bit(EFI_SYSTEM_TABLES, &efi.flags);
 356
 357         return 0;
 358 }
 359
 360 static int __init efi_runtime_init32(void)
 361 {
 362         efi_runtime_services_32_t *runtime;
 363
 364         runtime = early_memremap((unsigned long)efi.systab->runtime,
 365                         sizeof(efi_runtime_services_32_t));
 366         if (!runtime) {
 367                 pr_err("Could not map the runtime service table!\n");
 368                 return -ENOMEM;
 369         }
 370
 371         /*
 372          * We will only need *early* access to the SetVirtualAddressMap
 373          * EFI runtime service. All other runtime services will be called
 374          * via the virtual mapping.
 375          */
 376         efi_phys.set_virtual_address_map =
 377                         (efi_set_virtual_address_map_t *)
 378                         (unsigned long)runtime->set_virtual_address_map;
 379         early_memunmap(runtime, sizeof(efi_runtime_services_32_t));
 380
 381         return 0;
 382 }
 383
 384 static int __init efi_runtime_init64(void)
 385 {
 386         efi_runtime_services_64_t *runtime;
 387
 388         runtime = early_memremap((unsigned long)efi.systab->runtime,
 389                         sizeof(efi_runtime_services_64_t));
 390         if (!runtime) {
 391                 pr_err("Could not map the runtime service table!\n");
 392                 return -ENOMEM;
 393         }
 394
 395         /*
 396          * We will only need *early* access to the SetVirtualAddressMap
 397          * EFI runtime service. All other runtime services will be called
 398          * via the virtual mapping.
 399          */
 400         efi_phys.set_virtual_address_map =
 401                         (efi_set_virtual_address_map_t *)
 402                         (unsigned long)runtime->set_virtual_address_map;
 403         early_memunmap(runtime, sizeof(efi_runtime_services_64_t));
 404
 405         return 0;
 406 }
 407
 408 static int __init efi_runtime_init(void)
 409 {
 410         int rv;
 411
 412         /*
 413          * Check out the runtime services table. We need to map
 414          * the runtime services table so that we can grab the physical
 415          * address of several of the EFI runtime functions, needed to
 416          * set the firmware into virtual mode.
 417          *
 418          * When EFI_PARAVIRT is in force then we could not map runtime
 419          * service memory region because we do not have direct access to it.
 420          * However, runtime services are available through proxy functions
 421          * (e.g. in case of Xen dom0 EFI implementation they call special
 422          * hypercall which executes relevant EFI functions) and that is why
 423          * they are always enabled.
 424          */
 425
 426         if (!efi_enabled(EFI_PARAVIRT)) {
 427                 if (efi_enabled(EFI_64BIT))
 428                         rv = efi_runtime_init64();
 429                 else
 430                         rv = efi_runtime_init32();
 431
 432                 if (rv)
 433                         return rv;
 434         }
 435
 436         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 437
 438         return 0;
 439 }
 440
 441 static int __init efi_memmap_init(void)
 442 {
 443         if (efi_enabled(EFI_PARAVIRT))
 444                 return 0;
 445
 446         /* Map the EFI memory map */
 447         memmap.map = early_memremap((unsigned long)memmap.phys_map,
 448                                    memmap.nr_map * memmap.desc_size);
 449         if (memmap.map == NULL) {
 450                 pr_err("Could not map the memory map!\n");
 451                 return -ENOMEM;
 452         }
 453         memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
 454
 455         if (add_efi_memmap)
 456                 do_add_efi_memmap();
 457
 458         set_bit(EFI_MEMMAP, &efi.flags);
 459
 460         return 0;
 461 }
 462
 463 void __init efi_init(void)
 464 {
 465         efi_char16_t *c16;
 466         char vendor[100] = "unknown";
 467         int i = 0;
 468         void *tmp;
 469
 470 #ifdef CONFIG_X86_32
 471         if (boot_params.efi_info.efi_systab_hi ||
 472             boot_params.efi_info.efi_memmap_hi) {
 473                 pr_info("Table located above 4GB, disabling EFI.\n");
 474                 return;
 475         }
 476         efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
 477 #else
 478         efi_phys.systab = (efi_system_table_t *)
 479                           (boot_params.efi_info.efi_systab |
 480                           ((__u64)boot_params.efi_info.efi_systab_hi<<32));
 481 #endif
 482
 483         if (efi_systab_init(efi_phys.systab))
 484                 return;
 485
 486         efi.config_table = (unsigned long)efi.systab->tables;
 487         efi.fw_vendor    = (unsigned long)efi.systab->fw_vendor;
 488         efi.runtime      = (unsigned long)efi.systab->runtime;
 489
 490         /*
 491          * Show what we know for posterity
 492          */
 493         c16 = tmp = early_memremap(efi.systab->fw_vendor, 2);
 494         if (c16) {
 495                 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
 496                         vendor[i] = *c16++;
 497                 vendor[i] = '\0';
 498         } else
 499                 pr_err("Could not map the firmware vendor!\n");
 500         early_memunmap(tmp, 2);
 501
 502         pr_info("EFI v%u.%.02u by %s\n",
 503                 efi.systab->hdr.revision >> 16,
 504                 efi.systab->hdr.revision & 0xffff, vendor);
 505
 506         if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables))
 507                 return;
 508
 509         if (efi_config_init(arch_tables))
 510                 return;
 511
 512         /*
 513          * Note: We currently don't support runtime services on an EFI
 514          * that doesn't match the kernel 32/64-bit mode.
 515          */
 516
 517         if (!efi_runtime_supported())
 518                 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
 519         else {
 520                 if (efi_runtime_disabled() || efi_runtime_init())
 521                         return;
 522         }
 523         if (efi_memmap_init())
 524                 return;
 525
 526         if (efi_enabled(EFI_DBG))
 527                 print_efi_memmap();
 528
 529         efi_esrt_init();
 530 }
 531
 532 void __init efi_late_init(void)
 533 {
 534         efi_bgrt_init();
 535 }
 536
 537 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
 538 {
 539         u64 addr, npages;
 540
 541         addr = md->virt_addr;
 542         npages = md->num_pages;
 543
 544         memrange_efi_to_native(&addr, &npages);
 545
 546         if (executable)
 547                 set_memory_x(addr, npages);
 548         else
 549                 set_memory_nx(addr, npages);
 550 }
 551
 552 void __init runtime_code_page_mkexec(void)
 553 {
 554         efi_memory_desc_t *md;
 555         void *p;
 556
 557         /* Make EFI runtime service code area executable */
 558         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 559                 md = p;
 560
 561                 if (md->type != EFI_RUNTIME_SERVICES_CODE)
 562                         continue;
 563
 564                 efi_set_executable(md, true);
 565         }
 566 }
 567
 568 void __init efi_memory_uc(u64 addr, unsigned long size)
 569 {
 570         unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
 571         u64 npages;
 572
 573         npages = round_up(size, page_shift) / page_shift;
 574         memrange_efi_to_native(&addr, &npages);
 575         set_memory_uc(addr, npages);
 576 }
 577
 578 void __init old_map_region(efi_memory_desc_t *md)
 579 {
 580         u64 start_pfn, end_pfn, end;
 581         unsigned long size;
 582         void *va;
 583
 584         start_pfn = PFN_DOWN(md->phys_addr);
 585         size      = md->num_pages << PAGE_SHIFT;
 586         end       = md->phys_addr + size;
 587         end_pfn   = PFN_UP(end);
 588
 589         if (pfn_range_is_mapped(start_pfn, end_pfn)) {
 590                 va = __va(md->phys_addr);
 591
 592                 if (!(md->attribute & EFI_MEMORY_WB))
 593                         efi_memory_uc((u64)(unsigned long)va, size);
 594         } else
 595                 va = efi_ioremap(md->phys_addr, size,
 596                                  md->type, md->attribute);
 597
 598         md->virt_addr = (u64) (unsigned long) va;
 599         if (!va)
 600                 pr_err("ioremap of 0x%llX failed!\n",
 601                        (unsigned long long)md->phys_addr);
 602 }
 603
 604 /* Merge contiguous regions of the same type and attribute */
 605 static void __init efi_merge_regions(void)
 606 {
 607         void *p;
 608         efi_memory_desc_t *md, *prev_md = NULL;
 609
 610         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 611                 u64 prev_size;
 612                 md = p;
 613
 614                 if (!prev_md) {
 615                         prev_md = md;
 616                         continue;
 617                 }
 618
 619                 if (prev_md->type != md->type ||
 620                     prev_md->attribute != md->attribute) {
 621                         prev_md = md;
 622                         continue;
 623                 }
 624
 625                 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
 626
 627                 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
 628                         prev_md->num_pages += md->num_pages;
 629                         md->type = EFI_RESERVED_TYPE;
 630                         md->attribute = 0;
 631                         continue;
 632                 }
 633                 prev_md = md;
 634         }
 635 }
 636
 637 static void __init get_systab_virt_addr(efi_memory_desc_t *md)
 638 {
 639         unsigned long size;
 640         u64 end, systab;
 641
 642         size = md->num_pages << EFI_PAGE_SHIFT;
 643         end = md->phys_addr + size;
 644         systab = (u64)(unsigned long)efi_phys.systab;
 645         if (md->phys_addr <= systab && systab < end) {
 646                 systab += md->virt_addr - md->phys_addr;
 647                 efi.systab = (efi_system_table_t *)(unsigned long)systab;
 648         }
 649 }
 650
 651 static void __init save_runtime_map(void)
 652 {
 653 #ifdef CONFIG_KEXEC_CORE
 654         efi_memory_desc_t *md;
 655         void *tmp, *p, *q = NULL;
 656         int count = 0;
 657
 658         if (efi_enabled(EFI_OLD_MEMMAP))
 659                 return;
 660
 661         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 662                 md = p;
 663
 664                 if (!(md->attribute & EFI_MEMORY_RUNTIME) ||
 665                     (md->type == EFI_BOOT_SERVICES_CODE) ||
 666                     (md->type == EFI_BOOT_SERVICES_DATA))
 667                         continue;
 668                 tmp = krealloc(q, (count + 1) * memmap.desc_size, GFP_KERNEL);
 669                 if (!tmp)
 670                         goto out;
 671                 q = tmp;
 672
 673                 memcpy(q + count * memmap.desc_size, md, memmap.desc_size);
 674                 count++;
 675         }
 676
 677         efi_runtime_map_setup(q, count, memmap.desc_size);
 678         return;
 679
 680 out:
 681         kfree(q);
 682         pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
 683 #endif
 684 }
 685
 686 static void *realloc_pages(void *old_memmap, int old_shift)
 687 {
 688         void *ret;
 689
 690         ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
 691         if (!ret)
 692                 goto out;
 693
 694         /*
 695          * A first-time allocation doesn't have anything to copy.
 696          */
 697         if (!old_memmap)
 698                 return ret;
 699
 700         memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
 701
 702 out:
 703         free_pages((unsigned long)old_memmap, old_shift);
 704         return ret;
 705 }
 706
 707 /*
 708  * Iterate the EFI memory map in reverse order because the regions
 709  * will be mapped top-down. The end result is the same as if we had
 710  * mapped things forward, but doesn't require us to change the
 711  * existing implementation of efi_map_region().
 712  */
 713 static inline void *efi_map_next_entry_reverse(void *entry)
 714 {
 715         /* Initial call */
 716         if (!entry)
 717                 return memmap.map_end - memmap.desc_size;
 718
 719         entry -= memmap.desc_size;
 720         if (entry < memmap.map)
 721                 return NULL;
 722
 723         return entry;
 724 }
 725
 726 /*
 727  * efi_map_next_entry - Return the next EFI memory map descriptor
 728  * @entry: Previous EFI memory map descriptor
 729  *
 730  * This is a helper function to iterate over the EFI memory map, which
 731  * we do in different orders depending on the current configuration.
 732  *
 733  * To begin traversing the memory map @entry must be %NULL.
 734  *
 735  * Returns %NULL when we reach the end of the memory map.
 736  */
 737 static void *efi_map_next_entry(void *entry)
 738 {
 739         if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) {
 740                 /*
 741                  * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
 742                  * config table feature requires us to map all entries
 743                  * in the same order as they appear in the EFI memory
 744                  * map. That is to say, entry N must have a lower
 745                  * virtual address than entry N+1. This is because the
 746                  * firmware toolchain leaves relative references in
 747                  * the code/data sections, which are split and become
 748                  * separate EFI memory regions. Mapping things
 749                  * out-of-order leads to the firmware accessing
 750                  * unmapped addresses.
 751                  *
 752                  * Since we need to map things this way whether or not
 753                  * the kernel actually makes use of
 754                  * EFI_PROPERTIES_TABLE, let's just switch to this
 755                  * scheme by default for 64-bit.
 756                  */
 757                 return efi_map_next_entry_reverse(entry);
 758         }
 759
 760         /* Initial call */
 761         if (!entry)
 762                 return memmap.map;
 763
 764         entry += memmap.desc_size;
 765         if (entry >= memmap.map_end)
 766                 return NULL;
 767
 768         return entry;
 769 }
 770
 771 /*
 772  * Map the efi memory ranges of the runtime services and update new_mmap with
 773  * virtual addresses.
 774  */
 775 static void * __init efi_map_regions(int *count, int *pg_shift)
 776 {
 777         void *p, *new_memmap = NULL;
 778         unsigned long left = 0;
 779         efi_memory_desc_t *md;
 780
 781         p = NULL;
 782         while ((p = efi_map_next_entry(p))) {
 783                 md = p;
 784                 if (!(md->attribute & EFI_MEMORY_RUNTIME)) {
 785 #ifdef CONFIG_X86_64
 786                         if (md->type != EFI_BOOT_SERVICES_CODE &&
 787                             md->type != EFI_BOOT_SERVICES_DATA)
 788 #endif
 789                                 continue;
 790                 }
 791
 792                 efi_map_region(md);
 793                 get_systab_virt_addr(md);
 794
 795                 if (left < memmap.desc_size) {
 796                         new_memmap = realloc_pages(new_memmap, *pg_shift);
 797                         if (!new_memmap)
 798                                 return NULL;
 799
 800                         left += PAGE_SIZE << *pg_shift;
 801                         (*pg_shift)++;
 802                 }
 803
 804                 memcpy(new_memmap + (*count * memmap.desc_size), md,
 805                        memmap.desc_size);
 806
 807                 left -= memmap.desc_size;
 808                 (*count)++;
 809         }
 810
 811         return new_memmap;
 812 }
 813
 814 static void __init kexec_enter_virtual_mode(void)
 815 {
 816 #ifdef CONFIG_KEXEC_CORE
 817         efi_memory_desc_t *md;
 818         void *p;
 819
 820         efi.systab = NULL;
 821
 822         /*
 823          * We don't do virtual mode, since we don't do runtime services, on
 824          * non-native EFI
 825          */
 826         if (!efi_is_native()) {
 827                 efi_unmap_memmap();
 828                 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 829                 return;
 830         }
 831
 832         /*
 833         * Map efi regions which were passed via setup_data. The virt_addr is a
 834         * fixed addr which was used in first kernel of a kexec boot.
 835         */
 836         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 837                 md = p;
 838                 efi_map_region_fixed(md); /* FIXME: add error handling */
 839                 get_systab_virt_addr(md);
 840         }
 841
 842         save_runtime_map();
 843
 844         BUG_ON(!efi.systab);
 845
 846         efi_sync_low_kernel_mappings();
 847
 848         /*
 849          * Now that EFI is in virtual mode, update the function
 850          * pointers in the runtime service table to the new virtual addresses.
 851          *
 852          * Call EFI services through wrapper functions.
 853          */
 854         efi.runtime_version = efi_systab.hdr.revision;
 855
 856         efi_native_runtime_setup();
 857
 858         efi.set_virtual_address_map = NULL;
 859
 860         if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
 861                 runtime_code_page_mkexec();
 862
 863         /* clean DUMMY object */
 864         efi_delete_dummy_variable();
 865 #endif
 866 }
 867
 868 /*
 869  * This function will switch the EFI runtime services to virtual mode.
 870  * Essentially, we look through the EFI memmap and map every region that
 871  * has the runtime attribute bit set in its memory descriptor into the
 872  * ->trampoline_pgd page table using a top-down VA allocation scheme.
 873  *
 874  * The old method which used to update that memory descriptor with the
 875  * virtual address obtained from ioremap() is still supported when the
 876  * kernel is booted with efi=old_map on its command line. Same old
 877  * method enabled the runtime services to be called without having to
 878  * thunk back into physical mode for every invocation.
 879  *
 880  * The new method does a pagetable switch in a preemption-safe manner
 881  * so that we're in a different address space when calling a runtime
 882  * function. For function arguments passing we do copy the PGDs of the
 883  * kernel page table into ->trampoline_pgd prior to each call.
 884  *
 885  * Specially for kexec boot, efi runtime maps in previous kernel should
 886  * be passed in via setup_data. In that case runtime ranges will be mapped
 887  * to the same virtual addresses as the first kernel, see
 888  * kexec_enter_virtual_mode().
 889  */
 890 static void __init __efi_enter_virtual_mode(void)
 891 {
 892         int count = 0, pg_shift = 0;
 893         void *new_memmap = NULL;
 894         efi_status_t status;
 895
 896         efi.systab = NULL;
 897
 898         efi_merge_regions();
 899         new_memmap = efi_map_regions(&count, &pg_shift);
 900         if (!new_memmap) {
 901                 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
 902                 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 903                 return;
 904         }
 905
 906         save_runtime_map();
 907
 908         BUG_ON(!efi.systab);
 909
 910         if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift)) {
 911                 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 912                 return;
 913         }
 914
 915         efi_sync_low_kernel_mappings();
 916         efi_dump_pagetable();
 917
 918         if (efi_is_native()) {
 919                 status = phys_efi_set_virtual_address_map(
 920                                 memmap.desc_size * count,
 921                                 memmap.desc_size,
 922                                 memmap.desc_version,
 923                                 (efi_memory_desc_t *)__pa(new_memmap));
 924         } else {
 925                 status = efi_thunk_set_virtual_address_map(
 926                                 efi_phys.set_virtual_address_map,
 927                                 memmap.desc_size * count,
 928                                 memmap.desc_size,
 929                                 memmap.desc_version,
 930                                 (efi_memory_desc_t *)__pa(new_memmap));
 931         }
 932
 933         if (status != EFI_SUCCESS) {
 934                 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
 935                          status);
 936                 panic("EFI call to SetVirtualAddressMap() failed!");
 937         }
 938
 939         /*
 940          * Now that EFI is in virtual mode, update the function
 941          * pointers in the runtime service table to the new virtual addresses.
 942          *
 943          * Call EFI services through wrapper functions.
 944          */
 945         efi.runtime_version = efi_systab.hdr.revision;
 946
 947         if (efi_is_native())
 948                 efi_native_runtime_setup();
 949         else
 950                 efi_thunk_runtime_setup();
 951
 952         efi.set_virtual_address_map = NULL;
 953
 954         efi_runtime_mkexec();
 955
 956         /*
 957          * We mapped the descriptor array into the EFI pagetable above but we're
 958          * not unmapping it here. Here's why:
 959          *
 960          * We're copying select PGDs from the kernel page table to the EFI page
 961          * table and when we do so and make changes to those PGDs like unmapping
 962          * stuff from them, those changes appear in the kernel page table and we
 963          * go boom.
 964          *
 965          * From setup_real_mode():
 966          *
 967          * ...
 968          * trampoline_pgd[0] = init_level4_pgt[pgd_index(__PAGE_OFFSET)].pgd;
 969          *
 970          * In this particular case, our allocation is in PGD 0 of the EFI page
 971          * table but we've copied that PGD from PGD[272] of the EFI page table:
 972          *
 973          *      pgd_index(__PAGE_OFFSET = 0xffff880000000000) = 272
 974          *
 975          * where the direct memory mapping in kernel space is.
 976          *
 977          * new_memmap's VA comes from that direct mapping and thus clearing it,
 978          * it would get cleared in the kernel page table too.
 979          *
 980          * efi_cleanup_page_tables(__pa(new_memmap), 1 << pg_shift);
 981          */
 982         free_pages((unsigned long)new_memmap, pg_shift);
 983
 984         /* clean DUMMY object */
 985         efi_delete_dummy_variable();
 986 }
 987
 988 void __init efi_enter_virtual_mode(void)
 989 {
 990         if (efi_enabled(EFI_PARAVIRT))
 991                 return;
 992
 993         if (efi_setup)
 994                 kexec_enter_virtual_mode();
 995         else
 996                 __efi_enter_virtual_mode();
 997 }
 998
 999 /*
1000  * Convenience functions to obtain memory types and attributes
1001  */
1002 u32 efi_mem_type(unsigned long phys_addr)
1003 {
1004         efi_memory_desc_t *md;
1005         void *p;
1006
1007         if (!efi_enabled(EFI_MEMMAP))
1008                 return 0;
1009
1010         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1011                 md = p;
1012                 if ((md->phys_addr <= phys_addr) &&
1013                     (phys_addr < (md->phys_addr +
1014                                   (md->num_pages << EFI_PAGE_SHIFT))))
1015                         return md->type;
1016         }
1017         return 0;
1018 }
1019
1020 u64 efi_mem_attributes(unsigned long phys_addr)
1021 {
1022         efi_memory_desc_t *md;
1023         void *p;
1024
1025         if (!efi_enabled(EFI_MEMMAP))
1026                 return 0;
1027
1028         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1029                 md = p;
1030                 if ((md->phys_addr <= phys_addr) &&
1031                     (phys_addr < (md->phys_addr +
1032                                   (md->num_pages << EFI_PAGE_SHIFT))))
1033                         return md->attribute;
1034         }
1035         return 0;
1036 }
1037
1038 static int __init arch_parse_efi_cmdline(char *str)
1039 {
1040         if (!str) {
1041                 pr_warn("need at least one option\n");
1042                 return -EINVAL;
1043         }
1044
1045         if (parse_option_str(str, "old_map"))
1046                 set_bit(EFI_OLD_MEMMAP, &efi.flags);
1047         if (parse_option_str(str, "debug"))
1048                 set_bit(EFI_DBG, &efi.flags);
1049
1050         return 0;
1051 }
1052 early_param("efi", arch_parse_efi_cmdline);