arch/x86/kernel/e820_32.c

   1 #include <linux/kernel.h>
   2 #include <linux/types.h>
   3 #include <linux/init.h>
   4 #include <linux/bootmem.h>
   5 #include <linux/ioport.h>
   6 #include <linux/string.h>
   7 #include <linux/kexec.h>
   8 #include <linux/module.h>
   9 #include <linux/mm.h>
  10 #include <linux/efi.h>
  11 #include <linux/pfn.h>
  12 #include <linux/uaccess.h>
  13 #include <linux/suspend.h>
  14
  15 #include <asm/pgtable.h>
  16 #include <asm/page.h>
  17 #include <asm/e820.h>
  18 #include <asm/setup.h>
  19
  20 #ifdef CONFIG_EFI
  21 int efi_enabled = 0;
  22 EXPORT_SYMBOL(efi_enabled);
  23 #endif
  24
  25 struct e820map e820;
  26 struct change_member {
  27         struct e820entry *pbios; /* pointer to original bios entry */
  28         unsigned long long addr; /* address for this change point */
  29 };
  30 static struct change_member change_point_list[2*E820MAX] __initdata;
  31 static struct change_member *change_point[2*E820MAX] __initdata;
  32 static struct e820entry *overlap_list[E820MAX] __initdata;
  33 static struct e820entry new_bios[E820MAX] __initdata;
  34 /* For PCI or other memory-mapped resources */
  35 unsigned long pci_mem_start = 0x10000000;
  36 #ifdef CONFIG_PCI
  37 EXPORT_SYMBOL(pci_mem_start);
  38 #endif
  39 extern int user_defined_memmap;
  40
  41 static struct resource system_rom_resource = {
  42         .name   = "System ROM",
  43         .start  = 0xf0000,
  44         .end    = 0xfffff,
  45         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  46 };
  47
  48 static struct resource extension_rom_resource = {
  49         .name   = "Extension ROM",
  50         .start  = 0xe0000,
  51         .end    = 0xeffff,
  52         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  53 };
  54
  55 static struct resource adapter_rom_resources[] = { {
  56         .name   = "Adapter ROM",
  57         .start  = 0xc8000,
  58         .end    = 0,
  59         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  60 }, {
  61         .name   = "Adapter ROM",
  62         .start  = 0,
  63         .end    = 0,
  64         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  65 }, {
  66         .name   = "Adapter ROM",
  67         .start  = 0,
  68         .end    = 0,
  69         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  70 }, {
  71         .name   = "Adapter ROM",
  72         .start  = 0,
  73         .end    = 0,
  74         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  75 }, {
  76         .name   = "Adapter ROM",
  77         .start  = 0,
  78         .end    = 0,
  79         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  80 }, {
  81         .name   = "Adapter ROM",
  82         .start  = 0,
  83         .end    = 0,
  84         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  85 } };
  86
  87 static struct resource video_rom_resource = {
  88         .name   = "Video ROM",
  89         .start  = 0xc0000,
  90         .end    = 0xc7fff,
  91         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  92 };
  93
  94 #define ROMSIGNATURE 0xaa55
  95
  96 static int __init romsignature(const unsigned char *rom)
  97 {
  98         const unsigned short * const ptr = (const unsigned short *)rom;
  99         unsigned short sig;
 100
 101         return probe_kernel_address(ptr, sig) == 0 && sig == ROMSIGNATURE;
 102 }
 103
 104 static int __init romchecksum(const unsigned char *rom, unsigned long length)
 105 {
 106         unsigned char sum, c;
 107
 108         for (sum = 0; length && probe_kernel_address(rom++, c) == 0; length--)
 109                 sum += c;
 110         return !length && !sum;
 111 }
 112
 113 static void __init probe_roms(void)
 114 {
 115         const unsigned char *rom;
 116         unsigned long start, length, upper;
 117         unsigned char c;
 118         int i;
 119
 120         /* video rom */
 121         upper = adapter_rom_resources[0].start;
 122         for (start = video_rom_resource.start; start < upper; start += 2048) {
 123                 rom = isa_bus_to_virt(start);
 124                 if (!romsignature(rom))
 125                         continue;
 126
 127                 video_rom_resource.start = start;
 128
 129                 if (probe_kernel_address(rom + 2, c) != 0)
 130                         continue;
 131
 132                 /* 0 < length <= 0x7f * 512, historically */
 133                 length = c * 512;
 134
 135                 /* if checksum okay, trust length byte */
 136                 if (length && romchecksum(rom, length))
 137                         video_rom_resource.end = start + length - 1;
 138
 139                 request_resource(&iomem_resource, &video_rom_resource);
 140                 break;
 141         }
 142
 143         start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
 144         if (start < upper)
 145                 start = upper;
 146
 147         /* system rom */
 148         request_resource(&iomem_resource, &system_rom_resource);
 149         upper = system_rom_resource.start;
 150
 151         /* check for extension rom (ignore length byte!) */
 152         rom = isa_bus_to_virt(extension_rom_resource.start);
 153         if (romsignature(rom)) {
 154                 length = extension_rom_resource.end - extension_rom_resource.start + 1;
 155                 if (romchecksum(rom, length)) {
 156                         request_resource(&iomem_resource, &extension_rom_resource);
 157                         upper = extension_rom_resource.start;
 158                 }
 159         }
 160
 161         /* check for adapter roms on 2k boundaries */
 162         for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) {
 163                 rom = isa_bus_to_virt(start);
 164                 if (!romsignature(rom))
 165                         continue;
 166
 167                 if (probe_kernel_address(rom + 2, c) != 0)
 168                         continue;
 169
 170                 /* 0 < length <= 0x7f * 512, historically */
 171                 length = c * 512;
 172
 173                 /* but accept any length that fits if checksum okay */
 174                 if (!length || start + length > upper || !romchecksum(rom, length))
 175                         continue;
 176
 177                 adapter_rom_resources[i].start = start;
 178                 adapter_rom_resources[i].end = start + length - 1;
 179                 request_resource(&iomem_resource, &adapter_rom_resources[i]);
 180
 181                 start = adapter_rom_resources[i++].end & ~2047UL;
 182         }
 183 }
 184
 185 /*
 186  * Request address space for all standard RAM and ROM resources
 187  * and also for regions reported as reserved by the e820.
 188  */
 189 void __init legacy_init_iomem_resources(struct resource *code_resource,
 190                 struct resource *data_resource,
 191                 struct resource *bss_resource)
 192 {
 193         int i;
 194
 195         probe_roms();
 196         for (i = 0; i < e820.nr_map; i++) {
 197                 struct resource *res;
 198 #ifndef CONFIG_RESOURCES_64BIT
 199                 if (e820.map[i].addr + e820.map[i].size > 0x100000000ULL)
 200                         continue;
 201 #endif
 202                 res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
 203                 switch (e820.map[i].type) {
 204                 case E820_RAM:  res->name = "System RAM"; break;
 205                 case E820_ACPI: res->name = "ACPI Tables"; break;
 206                 case E820_NVS:  res->name = "ACPI Non-volatile Storage"; break;
 207                 default:        res->name = "reserved";
 208                 }
 209                 res->start = e820.map[i].addr;
 210                 res->end = res->start + e820.map[i].size - 1;
 211                 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 212                 if (request_resource(&iomem_resource, res)) {
 213                         kfree(res);
 214                         continue;
 215                 }
 216                 if (e820.map[i].type == E820_RAM) {
 217                         /*
 218                          *  We don't know which RAM region contains kernel data,
 219                          *  so we try it repeatedly and let the resource manager
 220                          *  test it.
 221                          */
 222                         request_resource(res, code_resource);
 223                         request_resource(res, data_resource);
 224                         request_resource(res, bss_resource);
 225 #ifdef CONFIG_KEXEC
 226                         if (crashk_res.start != crashk_res.end)
 227                                 request_resource(res, &crashk_res);
 228 #endif
 229                 }
 230         }
 231 }
 232
 233 #if defined(CONFIG_PM) && defined(CONFIG_HIBERNATION)
 234 /**
 235  * e820_mark_nosave_regions - Find the ranges of physical addresses that do not
 236  * correspond to e820 RAM areas and mark the corresponding pages as nosave for
 237  * hibernation.
 238  *
 239  * This function requires the e820 map to be sorted and without any
 240  * overlapping entries and assumes the first e820 area to be RAM.
 241  */
 242 void __init e820_mark_nosave_regions(void)
 243 {
 244         int i;
 245         unsigned long pfn;
 246
 247         pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size);
 248         for (i = 1; i < e820.nr_map; i++) {
 249                 struct e820entry *ei = &e820.map[i];
 250
 251                 if (pfn < PFN_UP(ei->addr))
 252                         register_nosave_region(pfn, PFN_UP(ei->addr));
 253
 254                 pfn = PFN_DOWN(ei->addr + ei->size);
 255                 if (ei->type != E820_RAM)
 256                         register_nosave_region(PFN_UP(ei->addr), pfn);
 257
 258                 if (pfn >= max_low_pfn)
 259                         break;
 260         }
 261 }
 262 #endif
 263
 264 void __init add_memory_region(unsigned long long start,
 265                               unsigned long long size, int type)
 266 {
 267         int x;
 268
 269         if (!efi_enabled) {
 270                 x = e820.nr_map;
 271
 272                 if (x == E820MAX) {
 273                     printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
 274                     return;
 275                 }
 276
 277                 e820.map[x].addr = start;
 278                 e820.map[x].size = size;
 279                 e820.map[x].type = type;
 280                 e820.nr_map++;
 281         }
 282 } /* add_memory_region */
 283
 284 /*
 285  * Sanitize the BIOS e820 map.
 286  *
 287  * Some e820 responses include overlapping entries.  The following
 288  * replaces the original e820 map with a new one, removing overlaps.
 289  *
 290  */
 291 int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
 292 {
 293         struct change_member *change_tmp;
 294         unsigned long current_type, last_type;
 295         unsigned long long last_addr;
 296         int chgidx, still_changing;
 297         int overlap_entries;
 298         int new_bios_entry;
 299         int old_nr, new_nr, chg_nr;
 300         int i;
 301
 302         /*
 303                 Visually we're performing the following (1,2,3,4 = memory types)...
 304
 305                 Sample memory map (w/overlaps):
 306                    ____22__________________
 307                    ______________________4_
 308                    ____1111________________
 309                    _44_____________________
 310                    11111111________________
 311                    ____________________33__
 312                    ___________44___________
 313                    __________33333_________
 314                    ______________22________
 315                    ___________________2222_
 316                    _________111111111______
 317                    _____________________11_
 318                    _________________4______
 319
 320                 Sanitized equivalent (no overlap):
 321                    1_______________________
 322                    _44_____________________
 323                    ___1____________________
 324                    ____22__________________
 325                    ______11________________
 326                    _________1______________
 327                    __________3_____________
 328                    ___________44___________
 329                    _____________33_________
 330                    _______________2________
 331                    ________________1_______
 332                    _________________4______
 333                    ___________________2____
 334                    ____________________33__
 335                    ______________________4_
 336         */
 337         /* if there's only one memory region, don't bother */
 338         if (*pnr_map < 2) {
 339                 return -1;
 340         }
 341
 342         old_nr = *pnr_map;
 343
 344         /* bail out if we find any unreasonable addresses in bios map */
 345         for (i=0; i<old_nr; i++)
 346                 if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr) {
 347                         return -1;
 348                 }
 349
 350         /* create pointers for initial change-point information (for sorting) */
 351         for (i=0; i < 2*old_nr; i++)
 352                 change_point[i] = &change_point_list[i];
 353
 354         /* record all known change-points (starting and ending addresses),
 355            omitting those that are for empty memory regions */
 356         chgidx = 0;
 357         for (i=0; i < old_nr; i++)      {
 358                 if (biosmap[i].size != 0) {
 359                         change_point[chgidx]->addr = biosmap[i].addr;
 360                         change_point[chgidx++]->pbios = &biosmap[i];
 361                         change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
 362                         change_point[chgidx++]->pbios = &biosmap[i];
 363                 }
 364         }
 365         chg_nr = chgidx;        /* true number of change-points */
 366
 367         /* sort change-point list by memory addresses (low -> high) */
 368         still_changing = 1;
 369         while (still_changing)  {
 370                 still_changing = 0;
 371                 for (i=1; i < chg_nr; i++)  {
 372                         /* if <current_addr> > <last_addr>, swap */
 373                         /* or, if current=<start_addr> & last=<end_addr>, swap */
 374                         if ((change_point[i]->addr < change_point[i-1]->addr) ||
 375                                 ((change_point[i]->addr == change_point[i-1]->addr) &&
 376                                  (change_point[i]->addr == change_point[i]->pbios->addr) &&
 377                                  (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
 378                            )
 379                         {
 380                                 change_tmp = change_point[i];
 381                                 change_point[i] = change_point[i-1];
 382                                 change_point[i-1] = change_tmp;
 383                                 still_changing=1;
 384                         }
 385                 }
 386         }
 387
 388         /* create a new bios memory map, removing overlaps */
 389         overlap_entries=0;       /* number of entries in the overlap table */
 390         new_bios_entry=0;        /* index for creating new bios map entries */
 391         last_type = 0;           /* start with undefined memory type */
 392         last_addr = 0;           /* start with 0 as last starting address */
 393         /* loop through change-points, determining affect on the new bios map */
 394         for (chgidx=0; chgidx < chg_nr; chgidx++)
 395         {
 396                 /* keep track of all overlapping bios entries */
 397                 if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
 398                 {
 399                         /* add map entry to overlap list (> 1 entry implies an overlap) */
 400                         overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
 401                 }
 402                 else
 403                 {
 404                         /* remove entry from list (order independent, so swap with last) */
 405                         for (i=0; i<overlap_entries; i++)
 406                         {
 407                                 if (overlap_list[i] == change_point[chgidx]->pbios)
 408                                         overlap_list[i] = overlap_list[overlap_entries-1];
 409                         }
 410                         overlap_entries--;
 411                 }
 412                 /* if there are overlapping entries, decide which "type" to use */
 413                 /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
 414                 current_type = 0;
 415                 for (i=0; i<overlap_entries; i++)
 416                         if (overlap_list[i]->type > current_type)
 417                                 current_type = overlap_list[i]->type;
 418                 /* continue building up new bios map based on this information */
 419                 if (current_type != last_type)  {
 420                         if (last_type != 0)      {
 421                                 new_bios[new_bios_entry].size =
 422                                         change_point[chgidx]->addr - last_addr;
 423                                 /* move forward only if the new size was non-zero */
 424                                 if (new_bios[new_bios_entry].size != 0)
 425                                         if (++new_bios_entry >= E820MAX)
 426                                                 break;  /* no more space left for new bios entries */
 427                         }
 428                         if (current_type != 0)  {
 429                                 new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
 430                                 new_bios[new_bios_entry].type = current_type;
 431                                 last_addr=change_point[chgidx]->addr;
 432                         }
 433                         last_type = current_type;
 434                 }
 435         }
 436         new_nr = new_bios_entry;   /* retain count for new bios entries */
 437
 438         /* copy new bios mapping into original location */
 439         memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
 440         *pnr_map = new_nr;
 441
 442         return 0;
 443 }
 444
 445 /*
 446  * Copy the BIOS e820 map into a safe place.
 447  *
 448  * Sanity-check it while we're at it..
 449  *
 450  * If we're lucky and live on a modern system, the setup code
 451  * will have given us a memory map that we can use to properly
 452  * set up memory.  If we aren't, we'll fake a memory map.
 453  *
 454  * We check to see that the memory map contains at least 2 elements
 455  * before we'll use it, because the detection code in setup.S may
 456  * not be perfect and most every PC known to man has two memory
 457  * regions: one from 0 to 640k, and one from 1mb up.  (The IBM
 458  * thinkpad 560x, for example, does not cooperate with the memory
 459  * detection code.)
 460  */
 461 int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
 462 {
 463         /* Only one memory region (or negative)? Ignore it */
 464         if (nr_map < 2)
 465                 return -1;
 466
 467         do {
 468                 unsigned long long start = biosmap->addr;
 469                 unsigned long long size = biosmap->size;
 470                 unsigned long long end = start + size;
 471                 unsigned long type = biosmap->type;
 472
 473                 /* Overflow in 64 bits? Ignore the memory map. */
 474                 if (start > end)
 475                         return -1;
 476
 477                 /*
 478                  * Some BIOSes claim RAM in the 640k - 1M region.
 479                  * Not right. Fix it up.
 480                  */
 481                 if (type == E820_RAM) {
 482                         if (start < 0x100000ULL && end > 0xA0000ULL) {
 483                                 if (start < 0xA0000ULL)
 484                                         add_memory_region(start, 0xA0000ULL-start, type);
 485                                 if (end <= 0x100000ULL)
 486                                         continue;
 487                                 start = 0x100000ULL;
 488                                 size = end - start;
 489                         }
 490                 }
 491                 add_memory_region(start, size, type);
 492         } while (biosmap++,--nr_map);
 493         return 0;
 494 }
 495
 496 /*
 497  * Callback for efi_memory_walk.
 498  */
 499 static int __init
 500 efi_find_max_pfn(unsigned long start, unsigned long end, void *arg)
 501 {
 502         unsigned long *max_pfn = arg, pfn;
 503
 504         if (start < end) {
 505                 pfn = PFN_UP(end -1);
 506                 if (pfn > *max_pfn)
 507                         *max_pfn = pfn;
 508         }
 509         return 0;
 510 }
 511
 512 static int __init
 513 efi_memory_present_wrapper(unsigned long start, unsigned long end, void *arg)
 514 {
 515         memory_present(0, PFN_UP(start), PFN_DOWN(end));
 516         return 0;
 517 }
 518
 519 /*
 520  * Find the highest page frame number we have available
 521  */
 522 void __init find_max_pfn(void)
 523 {
 524         int i;
 525
 526         max_pfn = 0;
 527         if (efi_enabled) {
 528                 efi_memmap_walk(efi_find_max_pfn, &max_pfn);
 529                 efi_memmap_walk(efi_memory_present_wrapper, NULL);
 530                 return;
 531         }
 532
 533         for (i = 0; i < e820.nr_map; i++) {
 534                 unsigned long start, end;
 535                 /* RAM? */
 536                 if (e820.map[i].type != E820_RAM)
 537                         continue;
 538                 start = PFN_UP(e820.map[i].addr);
 539                 end = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
 540                 if (start >= end)
 541                         continue;
 542                 if (end > max_pfn)
 543                         max_pfn = end;
 544                 memory_present(0, start, end);
 545         }
 546 }
 547
 548 /*
 549  * Free all available memory for boot time allocation.  Used
 550  * as a callback function by efi_memory_walk()
 551  */
 552
 553 static int __init
 554 free_available_memory(unsigned long start, unsigned long end, void *arg)
 555 {
 556         /* check max_low_pfn */
 557         if (start >= (max_low_pfn << PAGE_SHIFT))
 558                 return 0;
 559         if (end >= (max_low_pfn << PAGE_SHIFT))
 560                 end = max_low_pfn << PAGE_SHIFT;
 561         if (start < end)
 562                 free_bootmem(start, end - start);
 563
 564         return 0;
 565 }
 566 /*
 567  * Register fully available low RAM pages with the bootmem allocator.
 568  */
 569 void __init register_bootmem_low_pages(unsigned long max_low_pfn)
 570 {
 571         int i;
 572
 573         if (efi_enabled) {
 574                 efi_memmap_walk(free_available_memory, NULL);
 575                 return;
 576         }
 577         for (i = 0; i < e820.nr_map; i++) {
 578                 unsigned long curr_pfn, last_pfn, size;
 579                 /*
 580                  * Reserve usable low memory
 581                  */
 582                 if (e820.map[i].type != E820_RAM)
 583                         continue;
 584                 /*
 585                  * We are rounding up the start address of usable memory:
 586                  */
 587                 curr_pfn = PFN_UP(e820.map[i].addr);
 588                 if (curr_pfn >= max_low_pfn)
 589                         continue;
 590                 /*
 591                  * ... and at the end of the usable range downwards:
 592                  */
 593                 last_pfn = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
 594
 595                 if (last_pfn > max_low_pfn)
 596                         last_pfn = max_low_pfn;
 597
 598                 /*
 599                  * .. finally, did all the rounding and playing
 600                  * around just make the area go away?
 601                  */
 602                 if (last_pfn <= curr_pfn)
 603                         continue;
 604
 605                 size = last_pfn - curr_pfn;
 606                 free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
 607         }
 608 }
 609
 610 void __init e820_register_memory(void)
 611 {
 612         unsigned long gapstart, gapsize, round;
 613         unsigned long long last;
 614         int i;
 615
 616         /*
 617          * Search for the biggest gap in the low 32 bits of the e820
 618          * memory space.
 619          */
 620         last = 0x100000000ull;
 621         gapstart = 0x10000000;
 622         gapsize = 0x400000;
 623         i = e820.nr_map;
 624         while (--i >= 0) {
 625                 unsigned long long start = e820.map[i].addr;
 626                 unsigned long long end = start + e820.map[i].size;
 627
 628                 /*
 629                  * Since "last" is at most 4GB, we know we'll
 630                  * fit in 32 bits if this condition is true
 631                  */
 632                 if (last > end) {
 633                         unsigned long gap = last - end;
 634
 635                         if (gap > gapsize) {
 636                                 gapsize = gap;
 637                                 gapstart = end;
 638                         }
 639                 }
 640                 if (start < last)
 641                         last = start;
 642         }
 643
 644         /*
 645          * See how much we want to round up: start off with
 646          * rounding to the next 1MB area.
 647          */
 648         round = 0x100000;
 649         while ((gapsize >> 4) > round)
 650                 round += round;
 651         /* Fun with two's complement */
 652         pci_mem_start = (gapstart + round) & -round;
 653
 654         printk("Allocating PCI resources starting at %08lx (gap: %08lx:%08lx)\n",
 655                 pci_mem_start, gapstart, gapsize);
 656 }
 657
 658 void __init print_memory_map(char *who)
 659 {
 660         int i;
 661
 662         for (i = 0; i < e820.nr_map; i++) {
 663                 printk(" %s: %016Lx - %016Lx ", who,
 664                         e820.map[i].addr,
 665                         e820.map[i].addr + e820.map[i].size);
 666                 switch (e820.map[i].type) {
 667                 case E820_RAM:  printk("(usable)\n");
 668                                 break;
 669                 case E820_RESERVED:
 670                                 printk("(reserved)\n");
 671                                 break;
 672                 case E820_ACPI:
 673                                 printk("(ACPI data)\n");
 674                                 break;
 675                 case E820_NVS:
 676                                 printk("(ACPI NVS)\n");
 677                                 break;
 678                 default:        printk("type %u\n", e820.map[i].type);
 679                                 break;
 680                 }
 681         }
 682 }
 683
 684 static __init __always_inline void efi_limit_regions(unsigned long long size)
 685 {
 686         unsigned long long current_addr = 0;
 687         efi_memory_desc_t *md, *next_md;
 688         void *p, *p1;
 689         int i, j;
 690
 691         j = 0;
 692         p1 = memmap.map;
 693         for (p = p1, i = 0; p < memmap.map_end; p += memmap.desc_size, i++) {
 694                 md = p;
 695                 next_md = p1;
 696                 current_addr = md->phys_addr +
 697                         PFN_PHYS(md->num_pages);
 698                 if (is_available_memory(md)) {
 699                         if (md->phys_addr >= size) continue;
 700                         memcpy(next_md, md, memmap.desc_size);
 701                         if (current_addr >= size) {
 702                                 next_md->num_pages -=
 703                                         PFN_UP(current_addr-size);
 704                         }
 705                         p1 += memmap.desc_size;
 706                         next_md = p1;
 707                         j++;
 708                 } else if ((md->attribute & EFI_MEMORY_RUNTIME) ==
 709                            EFI_MEMORY_RUNTIME) {
 710                         /* In order to make runtime services
 711                          * available we have to include runtime
 712                          * memory regions in memory map */
 713                         memcpy(next_md, md, memmap.desc_size);
 714                         p1 += memmap.desc_size;
 715                         next_md = p1;
 716                         j++;
 717                 }
 718         }
 719         memmap.nr_map = j;
 720         memmap.map_end = memmap.map +
 721                 (memmap.nr_map * memmap.desc_size);
 722 }
 723
 724 void __init limit_regions(unsigned long long size)
 725 {
 726         unsigned long long current_addr;
 727         int i;
 728
 729         print_memory_map("limit_regions start");
 730         if (efi_enabled) {
 731                 efi_limit_regions(size);
 732                 return;
 733         }
 734         for (i = 0; i < e820.nr_map; i++) {
 735                 current_addr = e820.map[i].addr + e820.map[i].size;
 736                 if (current_addr < size)
 737                         continue;
 738
 739                 if (e820.map[i].type != E820_RAM)
 740                         continue;
 741
 742                 if (e820.map[i].addr >= size) {
 743                         /*
 744                          * This region starts past the end of the
 745                          * requested size, skip it completely.
 746                          */
 747                         e820.nr_map = i;
 748                 } else {
 749                         e820.nr_map = i + 1;
 750                         e820.map[i].size -= current_addr - size;
 751                 }
 752                 print_memory_map("limit_regions endfor");
 753                 return;
 754         }
 755         print_memory_map("limit_regions endfunc");
 756 }
 757
 758 /*
 759  * This function checks if any part of the range <start,end> is mapped
 760  * with type.
 761  */
 762 int
 763 e820_any_mapped(u64 start, u64 end, unsigned type)
 764 {
 765         int i;
 766         for (i = 0; i < e820.nr_map; i++) {
 767                 const struct e820entry *ei = &e820.map[i];
 768                 if (type && ei->type != type)
 769                         continue;
 770                 if (ei->addr >= end || ei->addr + ei->size <= start)
 771                         continue;
 772                 return 1;
 773         }
 774         return 0;
 775 }
 776 EXPORT_SYMBOL_GPL(e820_any_mapped);
 777
 778  /*
 779   * This function checks if the entire range <start,end> is mapped with type.
 780   *
 781   * Note: this function only works correct if the e820 table is sorted and
 782   * not-overlapping, which is the case
 783   */
 784 int __init
 785 e820_all_mapped(unsigned long s, unsigned long e, unsigned type)
 786 {
 787         u64 start = s;
 788         u64 end = e;
 789         int i;
 790         for (i = 0; i < e820.nr_map; i++) {
 791                 struct e820entry *ei = &e820.map[i];
 792                 if (type && ei->type != type)
 793                         continue;
 794                 /* is the region (part) in overlap with the current region ?*/
 795                 if (ei->addr >= end || ei->addr + ei->size <= start)
 796                         continue;
 797                 /* if the region is at the beginning of <start,end> we move
 798                  * start to the end of the region since it's ok until there
 799                  */
 800                 if (ei->addr <= start)
 801                         start = ei->addr + ei->size;
 802                 /* if start is now at or beyond end, we're done, full
 803                  * coverage */
 804                 if (start >= end)
 805                         return 1; /* we're done */
 806         }
 807         return 0;
 808 }
 809
 810 static int __init parse_memmap(char *arg)
 811 {
 812         if (!arg)
 813                 return -EINVAL;
 814
 815         if (strcmp(arg, "exactmap") == 0) {
 816 #ifdef CONFIG_CRASH_DUMP
 817                 /* If we are doing a crash dump, we
 818                  * still need to know the real mem
 819                  * size before original memory map is
 820                  * reset.
 821                  */
 822                 find_max_pfn();
 823                 saved_max_pfn = max_pfn;
 824 #endif
 825                 e820.nr_map = 0;
 826                 user_defined_memmap = 1;
 827         } else {
 828                 /* If the user specifies memory size, we
 829                  * limit the BIOS-provided memory map to
 830                  * that size. exactmap can be used to specify
 831                  * the exact map. mem=number can be used to
 832                  * trim the existing memory map.
 833                  */
 834                 unsigned long long start_at, mem_size;
 835
 836                 mem_size = memparse(arg, &arg);
 837                 if (*arg == '@') {
 838                         start_at = memparse(arg+1, &arg);
 839                         add_memory_region(start_at, mem_size, E820_RAM);
 840                 } else if (*arg == '#') {
 841                         start_at = memparse(arg+1, &arg);
 842                         add_memory_region(start_at, mem_size, E820_ACPI);
 843                 } else if (*arg == '$') {
 844                         start_at = memparse(arg+1, &arg);
 845                         add_memory_region(start_at, mem_size, E820_RESERVED);
 846                 } else {
 847                         limit_regions(mem_size);
 848                         user_defined_memmap = 1;
 849                 }
 850         }
 851         return 0;
 852 }
 853 early_param("memmap", parse_memmap);