err.no Git - linux-2.6/blob - 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 struct e820map e820;
  21 struct change_member {
  22         struct e820entry *pbios; /* pointer to original bios entry */
  23         unsigned long long addr; /* address for this change point */
  24 };
  25 static struct change_member change_point_list[2*E820MAX] __initdata;
  26 static struct change_member *change_point[2*E820MAX] __initdata;
  27 static struct e820entry *overlap_list[E820MAX] __initdata;
  28 static struct e820entry new_bios[E820MAX] __initdata;
  29 /* For PCI or other memory-mapped resources */
  30 unsigned long pci_mem_start = 0x10000000;
  31 #ifdef CONFIG_PCI
  32 EXPORT_SYMBOL(pci_mem_start);
  33 #endif
  34 extern int user_defined_memmap;
  35
  36 static struct resource system_rom_resource = {
  37         .name   = "System ROM",
  38         .start  = 0xf0000,
  39         .end    = 0xfffff,
  40         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  41 };
  42
  43 static struct resource extension_rom_resource = {
  44         .name   = "Extension ROM",
  45         .start  = 0xe0000,
  46         .end    = 0xeffff,
  47         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  48 };
  49
  50 static struct resource adapter_rom_resources[] = { {
  51         .name   = "Adapter ROM",
  52         .start  = 0xc8000,
  53         .end    = 0,
  54         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  55 }, {
  56         .name   = "Adapter ROM",
  57         .start  = 0,
  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
  82 static struct resource video_rom_resource = {
  83         .name   = "Video ROM",
  84         .start  = 0xc0000,
  85         .end    = 0xc7fff,
  86         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  87 };
  88
  89 #define ROMSIGNATURE 0xaa55
  90
  91 static int __init romsignature(const unsigned char *rom)
  92 {
  93         const unsigned short * const ptr = (const unsigned short *)rom;
  94         unsigned short sig;
  95
  96         return probe_kernel_address(ptr, sig) == 0 && sig == ROMSIGNATURE;
  97 }
  98
  99 static int __init romchecksum(const unsigned char *rom, unsigned long length)
 100 {
 101         unsigned char sum, c;
 102
 103         for (sum = 0; length && probe_kernel_address(rom++, c) == 0; length--)
 104                 sum += c;
 105         return !length && !sum;
 106 }
 107
 108 static void __init probe_roms(void)
 109 {
 110         const unsigned char *rom;
 111         unsigned long start, length, upper;
 112         unsigned char c;
 113         int i;
 114
 115         /* video rom */
 116         upper = adapter_rom_resources[0].start;
 117         for (start = video_rom_resource.start; start < upper; start += 2048) {
 118                 rom = isa_bus_to_virt(start);
 119                 if (!romsignature(rom))
 120                         continue;
 121
 122                 video_rom_resource.start = start;
 123
 124                 if (probe_kernel_address(rom + 2, c) != 0)
 125                         continue;
 126
 127                 /* 0 < length <= 0x7f * 512, historically */
 128                 length = c * 512;
 129
 130                 /* if checksum okay, trust length byte */
 131                 if (length && romchecksum(rom, length))
 132                         video_rom_resource.end = start + length - 1;
 133
 134                 request_resource(&iomem_resource, &video_rom_resource);
 135                 break;
 136         }
 137
 138         start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
 139         if (start < upper)
 140                 start = upper;
 141
 142         /* system rom */
 143         request_resource(&iomem_resource, &system_rom_resource);
 144         upper = system_rom_resource.start;
 145
 146         /* check for extension rom (ignore length byte!) */
 147         rom = isa_bus_to_virt(extension_rom_resource.start);
 148         if (romsignature(rom)) {
 149                 length = extension_rom_resource.end - extension_rom_resource.start + 1;
 150                 if (romchecksum(rom, length)) {
 151                         request_resource(&iomem_resource, &extension_rom_resource);
 152                         upper = extension_rom_resource.start;
 153                 }
 154         }
 155
 156         /* check for adapter roms on 2k boundaries */
 157         for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) {
 158                 rom = isa_bus_to_virt(start);
 159                 if (!romsignature(rom))
 160                         continue;
 161
 162                 if (probe_kernel_address(rom + 2, c) != 0)
 163                         continue;
 164
 165                 /* 0 < length <= 0x7f * 512, historically */
 166                 length = c * 512;
 167
 168                 /* but accept any length that fits if checksum okay */
 169                 if (!length || start + length > upper || !romchecksum(rom, length))
 170                         continue;
 171
 172                 adapter_rom_resources[i].start = start;
 173                 adapter_rom_resources[i].end = start + length - 1;
 174                 request_resource(&iomem_resource, &adapter_rom_resources[i]);
 175
 176                 start = adapter_rom_resources[i++].end & ~2047UL;
 177         }
 178 }
 179
 180 /*
 181  * Request address space for all standard RAM and ROM resources
 182  * and also for regions reported as reserved by the e820.
 183  */
 184 void __init legacy_init_iomem_resources(struct resource *code_resource,
 185                 struct resource *data_resource,
 186                 struct resource *bss_resource)
 187 {
 188         int i;
 189
 190         probe_roms();
 191         for (i = 0; i < e820.nr_map; i++) {
 192                 struct resource *res;
 193 #ifndef CONFIG_RESOURCES_64BIT
 194                 if (e820.map[i].addr + e820.map[i].size > 0x100000000ULL)
 195                         continue;
 196 #endif
 197                 res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
 198                 switch (e820.map[i].type) {
 199                 case E820_RAM:  res->name = "System RAM"; break;
 200                 case E820_ACPI: res->name = "ACPI Tables"; break;
 201                 case E820_NVS:  res->name = "ACPI Non-volatile Storage"; break;
 202                 default:        res->name = "reserved";
 203                 }
 204                 res->start = e820.map[i].addr;
 205                 res->end = res->start + e820.map[i].size - 1;
 206                 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 207                 if (request_resource(&iomem_resource, res)) {
 208                         kfree(res);
 209                         continue;
 210                 }
 211                 if (e820.map[i].type == E820_RAM) {
 212                         /*
 213                          *  We don't know which RAM region contains kernel data,
 214                          *  so we try it repeatedly and let the resource manager
 215                          *  test it.
 216                          */
 217                         request_resource(res, code_resource);
 218                         request_resource(res, data_resource);
 219                         request_resource(res, bss_resource);
 220 #ifdef CONFIG_KEXEC
 221                         if (crashk_res.start != crashk_res.end)
 222                                 request_resource(res, &crashk_res);
 223 #endif
 224                 }
 225         }
 226 }
 227
 228 #if defined(CONFIG_PM) && defined(CONFIG_HIBERNATION)
 229 /**
 230  * e820_mark_nosave_regions - Find the ranges of physical addresses that do not
 231  * correspond to e820 RAM areas and mark the corresponding pages as nosave for
 232  * hibernation.
 233  *
 234  * This function requires the e820 map to be sorted and without any
 235  * overlapping entries and assumes the first e820 area to be RAM.
 236  */
 237 void __init e820_mark_nosave_regions(void)
 238 {
 239         int i;
 240         unsigned long pfn;
 241
 242         pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size);
 243         for (i = 1; i < e820.nr_map; i++) {
 244                 struct e820entry *ei = &e820.map[i];
 245
 246                 if (pfn < PFN_UP(ei->addr))
 247                         register_nosave_region(pfn, PFN_UP(ei->addr));
 248
 249                 pfn = PFN_DOWN(ei->addr + ei->size);
 250                 if (ei->type != E820_RAM)
 251                         register_nosave_region(PFN_UP(ei->addr), pfn);
 252
 253                 if (pfn >= max_low_pfn)
 254                         break;
 255         }
 256 }
 257 #endif
 258
 259 void __init add_memory_region(unsigned long long start,
 260                               unsigned long long size, int type)
 261 {
 262         int x;
 263
 264         if (!efi_enabled) {
 265                 x = e820.nr_map;
 266
 267                 if (x == E820MAX) {
 268                     printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
 269                     return;
 270                 }
 271
 272                 e820.map[x].addr = start;
 273                 e820.map[x].size = size;
 274                 e820.map[x].type = type;
 275                 e820.nr_map++;
 276         }
 277 } /* add_memory_region */
 278
 279 /*
 280  * Sanitize the BIOS e820 map.
 281  *
 282  * Some e820 responses include overlapping entries.  The following
 283  * replaces the original e820 map with a new one, removing overlaps.
 284  *
 285  */
 286 int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
 287 {
 288         struct change_member *change_tmp;
 289         unsigned long current_type, last_type;
 290         unsigned long long last_addr;
 291         int chgidx, still_changing;
 292         int overlap_entries;
 293         int new_bios_entry;
 294         int old_nr, new_nr, chg_nr;
 295         int i;
 296
 297         /*
 298                 Visually we're performing the following (1,2,3,4 = memory types)...
 299
 300                 Sample memory map (w/overlaps):
 301                    ____22__________________
 302                    ______________________4_
 303                    ____1111________________
 304                    _44_____________________
 305                    11111111________________
 306                    ____________________33__
 307                    ___________44___________
 308                    __________33333_________
 309                    ______________22________
 310                    ___________________2222_
 311                    _________111111111______
 312                    _____________________11_
 313                    _________________4______
 314
 315                 Sanitized equivalent (no overlap):
 316                    1_______________________
 317                    _44_____________________
 318                    ___1____________________
 319                    ____22__________________
 320                    ______11________________
 321                    _________1______________
 322                    __________3_____________
 323                    ___________44___________
 324                    _____________33_________
 325                    _______________2________
 326                    ________________1_______
 327                    _________________4______
 328                    ___________________2____
 329                    ____________________33__
 330                    ______________________4_
 331         */
 332         /* if there's only one memory region, don't bother */
 333         if (*pnr_map < 2) {
 334                 return -1;
 335         }
 336
 337         old_nr = *pnr_map;
 338
 339         /* bail out if we find any unreasonable addresses in bios map */
 340         for (i=0; i<old_nr; i++)
 341                 if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr) {
 342                         return -1;
 343                 }
 344
 345         /* create pointers for initial change-point information (for sorting) */
 346         for (i=0; i < 2*old_nr; i++)
 347                 change_point[i] = &change_point_list[i];
 348
 349         /* record all known change-points (starting and ending addresses),
 350            omitting those that are for empty memory regions */
 351         chgidx = 0;
 352         for (i=0; i < old_nr; i++)      {
 353                 if (biosmap[i].size != 0) {
 354                         change_point[chgidx]->addr = biosmap[i].addr;
 355                         change_point[chgidx++]->pbios = &biosmap[i];
 356                         change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
 357                         change_point[chgidx++]->pbios = &biosmap[i];
 358                 }
 359         }
 360         chg_nr = chgidx;        /* true number of change-points */
 361
 362         /* sort change-point list by memory addresses (low -> high) */
 363         still_changing = 1;
 364         while (still_changing)  {
 365                 still_changing = 0;
 366                 for (i=1; i < chg_nr; i++)  {
 367                         /* if <current_addr> > <last_addr>, swap */
 368                         /* or, if current=<start_addr> & last=<end_addr>, swap */
 369                         if ((change_point[i]->addr < change_point[i-1]->addr) ||
 370                                 ((change_point[i]->addr == change_point[i-1]->addr) &&
 371                                  (change_point[i]->addr == change_point[i]->pbios->addr) &&
 372                                  (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
 373                            )
 374                         {
 375                                 change_tmp = change_point[i];
 376                                 change_point[i] = change_point[i-1];
 377                                 change_point[i-1] = change_tmp;
 378                                 still_changing=1;
 379                         }
 380                 }
 381         }
 382
 383         /* create a new bios memory map, removing overlaps */
 384         overlap_entries=0;       /* number of entries in the overlap table */
 385         new_bios_entry=0;        /* index for creating new bios map entries */
 386         last_type = 0;           /* start with undefined memory type */
 387         last_addr = 0;           /* start with 0 as last starting address */
 388         /* loop through change-points, determining affect on the new bios map */
 389         for (chgidx=0; chgidx < chg_nr; chgidx++)
 390         {
 391                 /* keep track of all overlapping bios entries */
 392                 if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
 393                 {
 394                         /* add map entry to overlap list (> 1 entry implies an overlap) */
 395                         overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
 396                 }
 397                 else
 398                 {
 399                         /* remove entry from list (order independent, so swap with last) */
 400                         for (i=0; i<overlap_entries; i++)
 401                         {
 402                                 if (overlap_list[i] == change_point[chgidx]->pbios)
 403                                         overlap_list[i] = overlap_list[overlap_entries-1];
 404                         }
 405                         overlap_entries--;
 406                 }
 407                 /* if there are overlapping entries, decide which "type" to use */
 408                 /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
 409                 current_type = 0;
 410                 for (i=0; i<overlap_entries; i++)
 411                         if (overlap_list[i]->type > current_type)
 412                                 current_type = overlap_list[i]->type;
 413                 /* continue building up new bios map based on this information */
 414                 if (current_type != last_type)  {
 415                         if (last_type != 0)      {
 416                                 new_bios[new_bios_entry].size =
 417                                         change_point[chgidx]->addr - last_addr;
 418                                 /* move forward only if the new size was non-zero */
 419                                 if (new_bios[new_bios_entry].size != 0)
 420                                         if (++new_bios_entry >= E820MAX)
 421                                                 break;  /* no more space left for new bios entries */
 422                         }
 423                         if (current_type != 0)  {
 424                                 new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
 425                                 new_bios[new_bios_entry].type = current_type;
 426                                 last_addr=change_point[chgidx]->addr;
 427                         }
 428                         last_type = current_type;
 429                 }
 430         }
 431         new_nr = new_bios_entry;   /* retain count for new bios entries */
 432
 433         /* copy new bios mapping into original location */
 434         memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
 435         *pnr_map = new_nr;
 436
 437         return 0;
 438 }
 439
 440 /*
 441  * Copy the BIOS e820 map into a safe place.
 442  *
 443  * Sanity-check it while we're at it..
 444  *
 445  * If we're lucky and live on a modern system, the setup code
 446  * will have given us a memory map that we can use to properly
 447  * set up memory.  If we aren't, we'll fake a memory map.
 448  *
 449  * We check to see that the memory map contains at least 2 elements
 450  * before we'll use it, because the detection code in setup.S may
 451  * not be perfect and most every PC known to man has two memory
 452  * regions: one from 0 to 640k, and one from 1mb up.  (The IBM
 453  * thinkpad 560x, for example, does not cooperate with the memory
 454  * detection code.)
 455  */
 456 int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
 457 {
 458         /* Only one memory region (or negative)? Ignore it */
 459         if (nr_map < 2)
 460                 return -1;
 461
 462         do {
 463                 unsigned long long start = biosmap->addr;
 464                 unsigned long long size = biosmap->size;
 465                 unsigned long long end = start + size;
 466                 unsigned long type = biosmap->type;
 467
 468                 /* Overflow in 64 bits? Ignore the memory map. */
 469                 if (start > end)
 470                         return -1;
 471
 472                 /*
 473                  * Some BIOSes claim RAM in the 640k - 1M region.
 474                  * Not right. Fix it up.
 475                  */
 476                 if (type == E820_RAM) {
 477                         if (start < 0x100000ULL && end > 0xA0000ULL) {
 478                                 if (start < 0xA0000ULL)
 479                                         add_memory_region(start, 0xA0000ULL-start, type);
 480                                 if (end <= 0x100000ULL)
 481                                         continue;
 482                                 start = 0x100000ULL;
 483                                 size = end - start;
 484                         }
 485                 }
 486                 add_memory_region(start, size, type);
 487         } while (biosmap++,--nr_map);
 488         return 0;
 489 }
 490
 491 /*
 492  * Callback for efi_memory_walk.
 493  */
 494 static int __init
 495 efi_find_max_pfn(unsigned long start, unsigned long end, void *arg)
 496 {
 497         unsigned long *max_pfn = arg, pfn;
 498
 499         if (start < end) {
 500                 pfn = PFN_UP(end -1);
 501                 if (pfn > *max_pfn)
 502                         *max_pfn = pfn;
 503         }
 504         return 0;
 505 }
 506
 507 static int __init
 508 efi_memory_present_wrapper(unsigned long start, unsigned long end, void *arg)
 509 {
 510         memory_present(0, PFN_UP(start), PFN_DOWN(end));
 511         return 0;
 512 }
 513
 514 /*
 515  * Find the highest page frame number we have available
 516  */
 517 void __init find_max_pfn(void)
 518 {
 519         int i;
 520
 521         max_pfn = 0;
 522         if (efi_enabled) {
 523                 efi_memmap_walk(efi_find_max_pfn, &max_pfn);
 524                 efi_memmap_walk(efi_memory_present_wrapper, NULL);
 525                 return;
 526         }
 527
 528         for (i = 0; i < e820.nr_map; i++) {
 529                 unsigned long start, end;
 530                 /* RAM? */
 531                 if (e820.map[i].type != E820_RAM)
 532                         continue;
 533                 start = PFN_UP(e820.map[i].addr);
 534                 end = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
 535                 if (start >= end)
 536                         continue;
 537                 if (end > max_pfn)
 538                         max_pfn = end;
 539                 memory_present(0, start, end);
 540         }
 541 }
 542
 543 /*
 544  * Free all available memory for boot time allocation.  Used
 545  * as a callback function by efi_memory_walk()
 546  */
 547
 548 static int __init
 549 free_available_memory(unsigned long start, unsigned long end, void *arg)
 550 {
 551         /* check max_low_pfn */
 552         if (start >= (max_low_pfn << PAGE_SHIFT))
 553                 return 0;
 554         if (end >= (max_low_pfn << PAGE_SHIFT))
 555                 end = max_low_pfn << PAGE_SHIFT;
 556         if (start < end)
 557                 free_bootmem(start, end - start);
 558
 559         return 0;
 560 }
 561 /*
 562  * Register fully available low RAM pages with the bootmem allocator.
 563  */
 564 void __init register_bootmem_low_pages(unsigned long max_low_pfn)
 565 {
 566         int i;
 567
 568         if (efi_enabled) {
 569                 efi_memmap_walk(free_available_memory, NULL);
 570                 return;
 571         }
 572         for (i = 0; i < e820.nr_map; i++) {
 573                 unsigned long curr_pfn, last_pfn, size;
 574                 /*
 575                  * Reserve usable low memory
 576                  */
 577                 if (e820.map[i].type != E820_RAM)
 578                         continue;
 579                 /*
 580                  * We are rounding up the start address of usable memory:
 581                  */
 582                 curr_pfn = PFN_UP(e820.map[i].addr);
 583                 if (curr_pfn >= max_low_pfn)
 584                         continue;
 585                 /*
 586                  * ... and at the end of the usable range downwards:
 587                  */
 588                 last_pfn = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
 589
 590                 if (last_pfn > max_low_pfn)
 591                         last_pfn = max_low_pfn;
 592
 593                 /*
 594                  * .. finally, did all the rounding and playing
 595                  * around just make the area go away?
 596                  */
 597                 if (last_pfn <= curr_pfn)
 598                         continue;
 599
 600                 size = last_pfn - curr_pfn;
 601                 free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
 602         }
 603 }
 604
 605 void __init e820_register_memory(void)
 606 {
 607         unsigned long gapstart, gapsize, round;
 608         unsigned long long last;
 609         int i;
 610
 611         /*
 612          * Search for the biggest gap in the low 32 bits of the e820
 613          * memory space.
 614          */
 615         last = 0x100000000ull;
 616         gapstart = 0x10000000;
 617         gapsize = 0x400000;
 618         i = e820.nr_map;
 619         while (--i >= 0) {
 620                 unsigned long long start = e820.map[i].addr;
 621                 unsigned long long end = start + e820.map[i].size;
 622
 623                 /*
 624                  * Since "last" is at most 4GB, we know we'll
 625                  * fit in 32 bits if this condition is true
 626                  */
 627                 if (last > end) {
 628                         unsigned long gap = last - end;
 629
 630                         if (gap > gapsize) {
 631                                 gapsize = gap;
 632                                 gapstart = end;
 633                         }
 634                 }
 635                 if (start < last)
 636                         last = start;
 637         }
 638
 639         /*
 640          * See how much we want to round up: start off with
 641          * rounding to the next 1MB area.
 642          */
 643         round = 0x100000;
 644         while ((gapsize >> 4) > round)
 645                 round += round;
 646         /* Fun with two's complement */
 647         pci_mem_start = (gapstart + round) & -round;
 648
 649         printk("Allocating PCI resources starting at %08lx (gap: %08lx:%08lx)\n",
 650                 pci_mem_start, gapstart, gapsize);
 651 }
 652
 653 void __init print_memory_map(char *who)
 654 {
 655         int i;
 656
 657         for (i = 0; i < e820.nr_map; i++) {
 658                 printk(" %s: %016Lx - %016Lx ", who,
 659                         e820.map[i].addr,
 660                         e820.map[i].addr + e820.map[i].size);
 661                 switch (e820.map[i].type) {
 662                 case E820_RAM:  printk("(usable)\n");
 663                                 break;
 664                 case E820_RESERVED:
 665                                 printk("(reserved)\n");
 666                                 break;
 667                 case E820_ACPI:
 668                                 printk("(ACPI data)\n");
 669                                 break;
 670                 case E820_NVS:
 671                                 printk("(ACPI NVS)\n");
 672                                 break;
 673                 default:        printk("type %u\n", e820.map[i].type);
 674                                 break;
 675                 }
 676         }
 677 }
 678
 679 static __init __always_inline void efi_limit_regions(unsigned long long size)
 680 {
 681         unsigned long long current_addr = 0;
 682         efi_memory_desc_t *md, *next_md;
 683         void *p, *p1;
 684         int i, j;
 685
 686         j = 0;
 687         p1 = memmap.map;
 688         for (p = p1, i = 0; p < memmap.map_end; p += memmap.desc_size, i++) {
 689                 md = p;
 690                 next_md = p1;
 691                 current_addr = md->phys_addr +
 692                         PFN_PHYS(md->num_pages);
 693                 if (is_available_memory(md)) {
 694                         if (md->phys_addr >= size) continue;
 695                         memcpy(next_md, md, memmap.desc_size);
 696                         if (current_addr >= size) {
 697                                 next_md->num_pages -=
 698                                         PFN_UP(current_addr-size);
 699                         }
 700                         p1 += memmap.desc_size;
 701                         next_md = p1;
 702                         j++;
 703                 } else if ((md->attribute & EFI_MEMORY_RUNTIME) ==
 704                            EFI_MEMORY_RUNTIME) {
 705                         /* In order to make runtime services
 706                          * available we have to include runtime
 707                          * memory regions in memory map */
 708                         memcpy(next_md, md, memmap.desc_size);
 709                         p1 += memmap.desc_size;
 710                         next_md = p1;
 711                         j++;
 712                 }
 713         }
 714         memmap.nr_map = j;
 715         memmap.map_end = memmap.map +
 716                 (memmap.nr_map * memmap.desc_size);
 717 }
 718
 719 void __init limit_regions(unsigned long long size)
 720 {
 721         unsigned long long current_addr;
 722         int i;
 723
 724         print_memory_map("limit_regions start");
 725         if (efi_enabled) {
 726                 efi_limit_regions(size);
 727                 return;
 728         }
 729         for (i = 0; i < e820.nr_map; i++) {
 730                 current_addr = e820.map[i].addr + e820.map[i].size;
 731                 if (current_addr < size)
 732                         continue;
 733
 734                 if (e820.map[i].type != E820_RAM)
 735                         continue;
 736
 737                 if (e820.map[i].addr >= size) {
 738                         /*
 739                          * This region starts past the end of the
 740                          * requested size, skip it completely.
 741                          */
 742                         e820.nr_map = i;
 743                 } else {
 744                         e820.nr_map = i + 1;
 745                         e820.map[i].size -= current_addr - size;
 746                 }
 747                 print_memory_map("limit_regions endfor");
 748                 return;
 749         }
 750         print_memory_map("limit_regions endfunc");
 751 }
 752
 753 /*
 754  * This function checks if any part of the range <start,end> is mapped
 755  * with type.
 756  */
 757 int
 758 e820_any_mapped(u64 start, u64 end, unsigned type)
 759 {
 760         int i;
 761         for (i = 0; i < e820.nr_map; i++) {
 762                 const struct e820entry *ei = &e820.map[i];
 763                 if (type && ei->type != type)
 764                         continue;
 765                 if (ei->addr >= end || ei->addr + ei->size <= start)
 766                         continue;
 767                 return 1;
 768         }
 769         return 0;
 770 }
 771 EXPORT_SYMBOL_GPL(e820_any_mapped);
 772
 773  /*
 774   * This function checks if the entire range <start,end> is mapped with type.
 775   *
 776   * Note: this function only works correct if the e820 table is sorted and
 777   * not-overlapping, which is the case
 778   */
 779 int __init
 780 e820_all_mapped(unsigned long s, unsigned long e, unsigned type)
 781 {
 782         u64 start = s;
 783         u64 end = e;
 784         int i;
 785         for (i = 0; i < e820.nr_map; i++) {
 786                 struct e820entry *ei = &e820.map[i];
 787                 if (type && ei->type != type)
 788                         continue;
 789                 /* is the region (part) in overlap with the current region ?*/
 790                 if (ei->addr >= end || ei->addr + ei->size <= start)
 791                         continue;
 792                 /* if the region is at the beginning of <start,end> we move
 793                  * start to the end of the region since it's ok until there
 794                  */
 795                 if (ei->addr <= start)
 796                         start = ei->addr + ei->size;
 797                 /* if start is now at or beyond end, we're done, full
 798                  * coverage */
 799                 if (start >= end)
 800                         return 1; /* we're done */
 801         }
 802         return 0;
 803 }
 804
 805 static int __init parse_memmap(char *arg)
 806 {
 807         if (!arg)
 808                 return -EINVAL;
 809
 810         if (strcmp(arg, "exactmap") == 0) {
 811 #ifdef CONFIG_CRASH_DUMP
 812                 /* If we are doing a crash dump, we
 813                  * still need to know the real mem
 814                  * size before original memory map is
 815                  * reset.
 816                  */
 817                 find_max_pfn();
 818                 saved_max_pfn = max_pfn;
 819 #endif
 820                 e820.nr_map = 0;
 821                 user_defined_memmap = 1;
 822         } else {
 823                 /* If the user specifies memory size, we
 824                  * limit the BIOS-provided memory map to
 825                  * that size. exactmap can be used to specify
 826                  * the exact map. mem=number can be used to
 827                  * trim the existing memory map.
 828                  */
 829                 unsigned long long start_at, mem_size;
 830
 831                 mem_size = memparse(arg, &arg);
 832                 if (*arg == '@') {
 833                         start_at = memparse(arg+1, &arg);
 834                         add_memory_region(start_at, mem_size, E820_RAM);
 835                 } else if (*arg == '#') {
 836                         start_at = memparse(arg+1, &arg);
 837                         add_memory_region(start_at, mem_size, E820_ACPI);
 838                 } else if (*arg == '$') {
 839                         start_at = memparse(arg+1, &arg);
 840                         add_memory_region(start_at, mem_size, E820_RESERVED);
 841                 } else {
 842                         limit_regions(mem_size);
 843                         user_defined_memmap = 1;
 844                 }
 845         }
 846         return 0;
 847 }
 848 early_param("memmap", parse_memmap);