arch/i386/kernel/e820.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
  14 #include <asm/pgtable.h>
  15 #include <asm/page.h>
  16 #include <asm/e820.h>
  17 #include <asm/setup.h>
  18
  19 #ifdef CONFIG_EFI
  20 int efi_enabled = 0;
  21 EXPORT_SYMBOL(efi_enabled);
  22 #endif
  23
  24 struct e820map e820;
  25 struct change_member {
  26         struct e820entry *pbios; /* pointer to original bios entry */
  27         unsigned long long addr; /* address for this change point */
  28 };
  29 static struct change_member change_point_list[2*E820MAX] __initdata;
  30 static struct change_member *change_point[2*E820MAX] __initdata;
  31 static struct e820entry *overlap_list[E820MAX] __initdata;
  32 static struct e820entry new_bios[E820MAX] __initdata;
  33 /* For PCI or other memory-mapped resources */
  34 unsigned long pci_mem_start = 0x10000000;
  35 #ifdef CONFIG_PCI
  36 EXPORT_SYMBOL(pci_mem_start);
  37 #endif
  38 extern int user_defined_memmap;
  39 struct resource data_resource = {
  40         .name   = "Kernel data",
  41         .start  = 0,
  42         .end    = 0,
  43         .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
  44 };
  45
  46 struct resource code_resource = {
  47         .name   = "Kernel code",
  48         .start  = 0,
  49         .end    = 0,
  50         .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
  51 };
  52
  53 static struct resource system_rom_resource = {
  54         .name   = "System ROM",
  55         .start  = 0xf0000,
  56         .end    = 0xfffff,
  57         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  58 };
  59
  60 static struct resource extension_rom_resource = {
  61         .name   = "Extension ROM",
  62         .start  = 0xe0000,
  63         .end    = 0xeffff,
  64         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  65 };
  66
  67 static struct resource adapter_rom_resources[] = { {
  68         .name   = "Adapter ROM",
  69         .start  = 0xc8000,
  70         .end    = 0,
  71         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  72 }, {
  73         .name   = "Adapter ROM",
  74         .start  = 0,
  75         .end    = 0,
  76         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  77 }, {
  78         .name   = "Adapter ROM",
  79         .start  = 0,
  80         .end    = 0,
  81         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  82 }, {
  83         .name   = "Adapter ROM",
  84         .start  = 0,
  85         .end    = 0,
  86         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  87 }, {
  88         .name   = "Adapter ROM",
  89         .start  = 0,
  90         .end    = 0,
  91         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  92 }, {
  93         .name   = "Adapter ROM",
  94         .start  = 0,
  95         .end    = 0,
  96         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
  97 } };
  98
  99 static struct resource video_rom_resource = {
 100         .name   = "Video ROM",
 101         .start  = 0xc0000,
 102         .end    = 0xc7fff,
 103         .flags  = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
 104 };
 105
 106 static struct resource video_ram_resource = {
 107         .name   = "Video RAM area",
 108         .start  = 0xa0000,
 109         .end    = 0xbffff,
 110         .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
 111 };
 112
 113 static struct resource standard_io_resources[] = { {
 114         .name   = "dma1",
 115         .start  = 0x0000,
 116         .end    = 0x001f,
 117         .flags  = IORESOURCE_BUSY | IORESOURCE_IO
 118 }, {
 119         .name   = "pic1",
 120         .start  = 0x0020,
 121         .end    = 0x0021,
 122         .flags  = IORESOURCE_BUSY | IORESOURCE_IO
 123 }, {
 124         .name   = "timer0",
 125         .start  = 0x0040,
 126         .end    = 0x0043,
 127         .flags  = IORESOURCE_BUSY | IORESOURCE_IO
 128 }, {
 129         .name   = "timer1",
 130         .start  = 0x0050,
 131         .end    = 0x0053,
 132         .flags  = IORESOURCE_BUSY | IORESOURCE_IO
 133 }, {
 134         .name   = "keyboard",
 135         .start  = 0x0060,
 136         .end    = 0x006f,
 137         .flags  = IORESOURCE_BUSY | IORESOURCE_IO
 138 }, {
 139         .name   = "dma page reg",
 140         .start  = 0x0080,
 141         .end    = 0x008f,
 142         .flags  = IORESOURCE_BUSY | IORESOURCE_IO
 143 }, {
 144         .name   = "pic2",
 145         .start  = 0x00a0,
 146         .end    = 0x00a1,
 147         .flags  = IORESOURCE_BUSY | IORESOURCE_IO
 148 }, {
 149         .name   = "dma2",
 150         .start  = 0x00c0,
 151         .end    = 0x00df,
 152         .flags  = IORESOURCE_BUSY | IORESOURCE_IO
 153 }, {
 154         .name   = "fpu",
 155         .start  = 0x00f0,
 156         .end    = 0x00ff,
 157         .flags  = IORESOURCE_BUSY | IORESOURCE_IO
 158 } };
 159
 160 #define ROMSIGNATURE 0xaa55
 161
 162 static int __init romsignature(const unsigned char *rom)
 163 {
 164         const unsigned short * const ptr = (const unsigned short *)rom;
 165         unsigned short sig;
 166
 167         return probe_kernel_address(ptr, sig) == 0 && sig == ROMSIGNATURE;
 168 }
 169
 170 static int __init romchecksum(const unsigned char *rom, unsigned long length)
 171 {
 172         unsigned char sum, c;
 173
 174         for (sum = 0; length && probe_kernel_address(rom++, c) == 0; length--)
 175                 sum += c;
 176         return !length && !sum;
 177 }
 178
 179 static void __init probe_roms(void)
 180 {
 181         const unsigned char *rom;
 182         unsigned long start, length, upper;
 183         unsigned char c;
 184         int i;
 185
 186         /* video rom */
 187         upper = adapter_rom_resources[0].start;
 188         for (start = video_rom_resource.start; start < upper; start += 2048) {
 189                 rom = isa_bus_to_virt(start);
 190                 if (!romsignature(rom))
 191                         continue;
 192
 193                 video_rom_resource.start = start;
 194
 195                 if (probe_kernel_address(rom + 2, c) != 0)
 196                         continue;
 197
 198                 /* 0 < length <= 0x7f * 512, historically */
 199                 length = c * 512;
 200
 201                 /* if checksum okay, trust length byte */
 202                 if (length && romchecksum(rom, length))
 203                         video_rom_resource.end = start + length - 1;
 204
 205                 request_resource(&iomem_resource, &video_rom_resource);
 206                 break;
 207         }
 208
 209         start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
 210         if (start < upper)
 211                 start = upper;
 212
 213         /* system rom */
 214         request_resource(&iomem_resource, &system_rom_resource);
 215         upper = system_rom_resource.start;
 216
 217         /* check for extension rom (ignore length byte!) */
 218         rom = isa_bus_to_virt(extension_rom_resource.start);
 219         if (romsignature(rom)) {
 220                 length = extension_rom_resource.end - extension_rom_resource.start + 1;
 221                 if (romchecksum(rom, length)) {
 222                         request_resource(&iomem_resource, &extension_rom_resource);
 223                         upper = extension_rom_resource.start;
 224                 }
 225         }
 226
 227         /* check for adapter roms on 2k boundaries */
 228         for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) {
 229                 rom = isa_bus_to_virt(start);
 230                 if (!romsignature(rom))
 231                         continue;
 232
 233                 if (probe_kernel_address(rom + 2, c) != 0)
 234                         continue;
 235
 236                 /* 0 < length <= 0x7f * 512, historically */
 237                 length = c * 512;
 238
 239                 /* but accept any length that fits if checksum okay */
 240                 if (!length || start + length > upper || !romchecksum(rom, length))
 241                         continue;
 242
 243                 adapter_rom_resources[i].start = start;
 244                 adapter_rom_resources[i].end = start + length - 1;
 245                 request_resource(&iomem_resource, &adapter_rom_resources[i]);
 246
 247                 start = adapter_rom_resources[i++].end & ~2047UL;
 248         }
 249 }
 250
 251 /*
 252  * Request address space for all standard RAM and ROM resources
 253  * and also for regions reported as reserved by the e820.
 254  */
 255 static void __init
 256 legacy_init_iomem_resources(struct resource *code_resource, struct resource *data_resource)
 257 {
 258         int i;
 259
 260         probe_roms();
 261         for (i = 0; i < e820.nr_map; i++) {
 262                 struct resource *res;
 263 #ifndef CONFIG_RESOURCES_64BIT
 264                 if (e820.map[i].addr + e820.map[i].size > 0x100000000ULL)
 265                         continue;
 266 #endif
 267                 res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
 268                 switch (e820.map[i].type) {
 269                 case E820_RAM:  res->name = "System RAM"; break;
 270                 case E820_ACPI: res->name = "ACPI Tables"; break;
 271                 case E820_NVS:  res->name = "ACPI Non-volatile Storage"; break;
 272                 default:        res->name = "reserved";
 273                 }
 274                 res->start = e820.map[i].addr;
 275                 res->end = res->start + e820.map[i].size - 1;
 276                 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 277                 if (request_resource(&iomem_resource, res)) {
 278                         kfree(res);
 279                         continue;
 280                 }
 281                 if (e820.map[i].type == E820_RAM) {
 282                         /*
 283                          *  We don't know which RAM region contains kernel data,
 284                          *  so we try it repeatedly and let the resource manager
 285                          *  test it.
 286                          */
 287                         request_resource(res, code_resource);
 288                         request_resource(res, data_resource);
 289 #ifdef CONFIG_KEXEC
 290                         request_resource(res, &crashk_res);
 291 #endif
 292                 }
 293         }
 294 }
 295
 296 /*
 297  * Request address space for all standard resources
 298  *
 299  * This is called just before pcibios_init(), which is also a
 300  * subsys_initcall, but is linked in later (in arch/i386/pci/common.c).
 301  */
 302 static int __init request_standard_resources(void)
 303 {
 304         int i;
 305
 306         printk("Setting up standard PCI resources\n");
 307         if (efi_enabled)
 308                 efi_initialize_iomem_resources(&code_resource, &data_resource);
 309         else
 310                 legacy_init_iomem_resources(&code_resource, &data_resource);
 311
 312         /* EFI systems may still have VGA */
 313         request_resource(&iomem_resource, &video_ram_resource);
 314
 315         /* request I/O space for devices used on all i[345]86 PCs */
 316         for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
 317                 request_resource(&ioport_resource, &standard_io_resources[i]);
 318         return 0;
 319 }
 320
 321 subsys_initcall(request_standard_resources);
 322
 323 void __init add_memory_region(unsigned long long start,
 324                               unsigned long long size, int type)
 325 {
 326         int x;
 327
 328         if (!efi_enabled) {
 329                 x = e820.nr_map;
 330
 331                 if (x == E820MAX) {
 332                     printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
 333                     return;
 334                 }
 335
 336                 e820.map[x].addr = start;
 337                 e820.map[x].size = size;
 338                 e820.map[x].type = type;
 339                 e820.nr_map++;
 340         }
 341 } /* add_memory_region */
 342
 343 /*
 344  * Sanitize the BIOS e820 map.
 345  *
 346  * Some e820 responses include overlapping entries.  The following
 347  * replaces the original e820 map with a new one, removing overlaps.
 348  *
 349  */
 350 int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
 351 {
 352         struct change_member *change_tmp;
 353         unsigned long current_type, last_type;
 354         unsigned long long last_addr;
 355         int chgidx, still_changing;
 356         int overlap_entries;
 357         int new_bios_entry;
 358         int old_nr, new_nr, chg_nr;
 359         int i;
 360
 361         /*
 362                 Visually we're performing the following (1,2,3,4 = memory types)...
 363
 364                 Sample memory map (w/overlaps):
 365                    ____22__________________
 366                    ______________________4_
 367                    ____1111________________
 368                    _44_____________________
 369                    11111111________________
 370                    ____________________33__
 371                    ___________44___________
 372                    __________33333_________
 373                    ______________22________
 374                    ___________________2222_
 375                    _________111111111______
 376                    _____________________11_
 377                    _________________4______
 378
 379                 Sanitized equivalent (no overlap):
 380                    1_______________________
 381                    _44_____________________
 382                    ___1____________________
 383                    ____22__________________
 384                    ______11________________
 385                    _________1______________
 386                    __________3_____________
 387                    ___________44___________
 388                    _____________33_________
 389                    _______________2________
 390                    ________________1_______
 391                    _________________4______
 392                    ___________________2____
 393                    ____________________33__
 394                    ______________________4_
 395         */
 396         printk("sanitize start\n");
 397         /* if there's only one memory region, don't bother */
 398         if (*pnr_map < 2) {
 399                 printk("sanitize bail 0\n");
 400                 return -1;
 401         }
 402
 403         old_nr = *pnr_map;
 404
 405         /* bail out if we find any unreasonable addresses in bios map */
 406         for (i=0; i<old_nr; i++)
 407                 if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr) {
 408                         printk("sanitize bail 1\n");
 409                         return -1;
 410                 }
 411
 412         /* create pointers for initial change-point information (for sorting) */
 413         for (i=0; i < 2*old_nr; i++)
 414                 change_point[i] = &change_point_list[i];
 415
 416         /* record all known change-points (starting and ending addresses),
 417            omitting those that are for empty memory regions */
 418         chgidx = 0;
 419         for (i=0; i < old_nr; i++)      {
 420                 if (biosmap[i].size != 0) {
 421                         change_point[chgidx]->addr = biosmap[i].addr;
 422                         change_point[chgidx++]->pbios = &biosmap[i];
 423                         change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
 424                         change_point[chgidx++]->pbios = &biosmap[i];
 425                 }
 426         }
 427         chg_nr = chgidx;        /* true number of change-points */
 428
 429         /* sort change-point list by memory addresses (low -> high) */
 430         still_changing = 1;
 431         while (still_changing)  {
 432                 still_changing = 0;
 433                 for (i=1; i < chg_nr; i++)  {
 434                         /* if <current_addr> > <last_addr>, swap */
 435                         /* or, if current=<start_addr> & last=<end_addr>, swap */
 436                         if ((change_point[i]->addr < change_point[i-1]->addr) ||
 437                                 ((change_point[i]->addr == change_point[i-1]->addr) &&
 438                                  (change_point[i]->addr == change_point[i]->pbios->addr) &&
 439                                  (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
 440                            )
 441                         {
 442                                 change_tmp = change_point[i];
 443                                 change_point[i] = change_point[i-1];
 444                                 change_point[i-1] = change_tmp;
 445                                 still_changing=1;
 446                         }
 447                 }
 448         }
 449
 450         /* create a new bios memory map, removing overlaps */
 451         overlap_entries=0;       /* number of entries in the overlap table */
 452         new_bios_entry=0;        /* index for creating new bios map entries */
 453         last_type = 0;           /* start with undefined memory type */
 454         last_addr = 0;           /* start with 0 as last starting address */
 455         /* loop through change-points, determining affect on the new bios map */
 456         for (chgidx=0; chgidx < chg_nr; chgidx++)
 457         {
 458                 /* keep track of all overlapping bios entries */
 459                 if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
 460                 {
 461                         /* add map entry to overlap list (> 1 entry implies an overlap) */
 462                         overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
 463                 }
 464                 else
 465                 {
 466                         /* remove entry from list (order independent, so swap with last) */
 467                         for (i=0; i<overlap_entries; i++)
 468                         {
 469                                 if (overlap_list[i] == change_point[chgidx]->pbios)
 470                                         overlap_list[i] = overlap_list[overlap_entries-1];
 471                         }
 472                         overlap_entries--;
 473                 }
 474                 /* if there are overlapping entries, decide which "type" to use */
 475                 /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
 476                 current_type = 0;
 477                 for (i=0; i<overlap_entries; i++)
 478                         if (overlap_list[i]->type > current_type)
 479                                 current_type = overlap_list[i]->type;
 480                 /* continue building up new bios map based on this information */
 481                 if (current_type != last_type)  {
 482                         if (last_type != 0)      {
 483                                 new_bios[new_bios_entry].size =
 484                                         change_point[chgidx]->addr - last_addr;
 485                                 /* move forward only if the new size was non-zero */
 486                                 if (new_bios[new_bios_entry].size != 0)
 487                                         if (++new_bios_entry >= E820MAX)
 488                                                 break;  /* no more space left for new bios entries */
 489                         }
 490                         if (current_type != 0)  {
 491                                 new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
 492                                 new_bios[new_bios_entry].type = current_type;
 493                                 last_addr=change_point[chgidx]->addr;
 494                         }
 495                         last_type = current_type;
 496                 }
 497         }
 498         new_nr = new_bios_entry;   /* retain count for new bios entries */
 499
 500         /* copy new bios mapping into original location */
 501         memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
 502         *pnr_map = new_nr;
 503
 504         printk("sanitize end\n");
 505         return 0;
 506 }
 507
 508 /*
 509  * Copy the BIOS e820 map into a safe place.
 510  *
 511  * Sanity-check it while we're at it..
 512  *
 513  * If we're lucky and live on a modern system, the setup code
 514  * will have given us a memory map that we can use to properly
 515  * set up memory.  If we aren't, we'll fake a memory map.
 516  *
 517  * We check to see that the memory map contains at least 2 elements
 518  * before we'll use it, because the detection code in setup.S may
 519  * not be perfect and most every PC known to man has two memory
 520  * regions: one from 0 to 640k, and one from 1mb up.  (The IBM
 521  * thinkpad 560x, for example, does not cooperate with the memory
 522  * detection code.)
 523  */
 524 int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
 525 {
 526         /* Only one memory region (or negative)? Ignore it */
 527         if (nr_map < 2)
 528                 return -1;
 529
 530         do {
 531                 unsigned long long start = biosmap->addr;
 532                 unsigned long long size = biosmap->size;
 533                 unsigned long long end = start + size;
 534                 unsigned long type = biosmap->type;
 535                 printk("copy_e820_map() start: %016Lx size: %016Lx end: %016Lx type: %ld\n", start, size, end, type);
 536
 537                 /* Overflow in 64 bits? Ignore the memory map. */
 538                 if (start > end)
 539                         return -1;
 540
 541                 /*
 542                  * Some BIOSes claim RAM in the 640k - 1M region.
 543                  * Not right. Fix it up.
 544                  */
 545                 if (type == E820_RAM) {
 546                         printk("copy_e820_map() type is E820_RAM\n");
 547                         if (start < 0x100000ULL && end > 0xA0000ULL) {
 548                                 printk("copy_e820_map() lies in range...\n");
 549                                 if (start < 0xA0000ULL) {
 550                                         printk("copy_e820_map() start < 0xA0000ULL\n");
 551                                         add_memory_region(start, 0xA0000ULL-start, type);
 552                                 }
 553                                 if (end <= 0x100000ULL) {
 554                                         printk("copy_e820_map() end <= 0x100000ULL\n");
 555                                         continue;
 556                                 }
 557                                 start = 0x100000ULL;
 558                                 size = end - start;
 559                         }
 560                 }
 561                 add_memory_region(start, size, type);
 562         } while (biosmap++,--nr_map);
 563         return 0;
 564 }
 565
 566 /*
 567  * Callback for efi_memory_walk.
 568  */
 569 static int __init
 570 efi_find_max_pfn(unsigned long start, unsigned long end, void *arg)
 571 {
 572         unsigned long *max_pfn = arg, pfn;
 573
 574         if (start < end) {
 575                 pfn = PFN_UP(end -1);
 576                 if (pfn > *max_pfn)
 577                         *max_pfn = pfn;
 578         }
 579         return 0;
 580 }
 581
 582 static int __init
 583 efi_memory_present_wrapper(unsigned long start, unsigned long end, void *arg)
 584 {
 585         memory_present(0, PFN_UP(start), PFN_DOWN(end));
 586         return 0;
 587 }
 588
 589 /*
 590  * Find the highest page frame number we have available
 591  */
 592 void __init find_max_pfn(void)
 593 {
 594         int i;
 595
 596         max_pfn = 0;
 597         if (efi_enabled) {
 598                 efi_memmap_walk(efi_find_max_pfn, &max_pfn);
 599                 efi_memmap_walk(efi_memory_present_wrapper, NULL);
 600                 return;
 601         }
 602
 603         for (i = 0; i < e820.nr_map; i++) {
 604                 unsigned long start, end;
 605                 /* RAM? */
 606                 if (e820.map[i].type != E820_RAM)
 607                         continue;
 608                 start = PFN_UP(e820.map[i].addr);
 609                 end = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
 610                 if (start >= end)
 611                         continue;
 612                 if (end > max_pfn)
 613                         max_pfn = end;
 614                 memory_present(0, start, end);
 615         }
 616 }
 617
 618 /*
 619  * Free all available memory for boot time allocation.  Used
 620  * as a callback function by efi_memory_walk()
 621  */
 622
 623 static int __init
 624 free_available_memory(unsigned long start, unsigned long end, void *arg)
 625 {
 626         /* check max_low_pfn */
 627         if (start >= (max_low_pfn << PAGE_SHIFT))
 628                 return 0;
 629         if (end >= (max_low_pfn << PAGE_SHIFT))
 630                 end = max_low_pfn << PAGE_SHIFT;
 631         if (start < end)
 632                 free_bootmem(start, end - start);
 633
 634         return 0;
 635 }
 636 /*
 637  * Register fully available low RAM pages with the bootmem allocator.
 638  */
 639 void __init register_bootmem_low_pages(unsigned long max_low_pfn)
 640 {
 641         int i;
 642
 643         if (efi_enabled) {
 644                 efi_memmap_walk(free_available_memory, NULL);
 645                 return;
 646         }
 647         for (i = 0; i < e820.nr_map; i++) {
 648                 unsigned long curr_pfn, last_pfn, size;
 649                 /*
 650                  * Reserve usable low memory
 651                  */
 652                 if (e820.map[i].type != E820_RAM)
 653                         continue;
 654                 /*
 655                  * We are rounding up the start address of usable memory:
 656                  */
 657                 curr_pfn = PFN_UP(e820.map[i].addr);
 658                 if (curr_pfn >= max_low_pfn)
 659                         continue;
 660                 /*
 661                  * ... and at the end of the usable range downwards:
 662                  */
 663                 last_pfn = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
 664
 665                 if (last_pfn > max_low_pfn)
 666                         last_pfn = max_low_pfn;
 667
 668                 /*
 669                  * .. finally, did all the rounding and playing
 670                  * around just make the area go away?
 671                  */
 672                 if (last_pfn <= curr_pfn)
 673                         continue;
 674
 675                 size = last_pfn - curr_pfn;
 676                 free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
 677         }
 678 }
 679
 680 void __init e820_register_memory(void)
 681 {
 682         unsigned long gapstart, gapsize, round;
 683         unsigned long long last;
 684         int i;
 685
 686         /*
 687          * Search for the bigest gap in the low 32 bits of the e820
 688          * memory space.
 689          */
 690         last = 0x100000000ull;
 691         gapstart = 0x10000000;
 692         gapsize = 0x400000;
 693         i = e820.nr_map;
 694         while (--i >= 0) {
 695                 unsigned long long start = e820.map[i].addr;
 696                 unsigned long long end = start + e820.map[i].size;
 697
 698                 /*
 699                  * Since "last" is at most 4GB, we know we'll
 700                  * fit in 32 bits if this condition is true
 701                  */
 702                 if (last > end) {
 703                         unsigned long gap = last - end;
 704
 705                         if (gap > gapsize) {
 706                                 gapsize = gap;
 707                                 gapstart = end;
 708                         }
 709                 }
 710                 if (start < last)
 711                         last = start;
 712         }
 713
 714         /*
 715          * See how much we want to round up: start off with
 716          * rounding to the next 1MB area.
 717          */
 718         round = 0x100000;
 719         while ((gapsize >> 4) > round)
 720                 round += round;
 721         /* Fun with two's complement */
 722         pci_mem_start = (gapstart + round) & -round;
 723
 724         printk("Allocating PCI resources starting at %08lx (gap: %08lx:%08lx)\n",
 725                 pci_mem_start, gapstart, gapsize);
 726 }
 727
 728 void __init print_memory_map(char *who)
 729 {
 730         int i;
 731
 732         for (i = 0; i < e820.nr_map; i++) {
 733                 printk(" %s: %016Lx - %016Lx ", who,
 734                         e820.map[i].addr,
 735                         e820.map[i].addr + e820.map[i].size);
 736                 switch (e820.map[i].type) {
 737                 case E820_RAM:  printk("(usable)\n");
 738                                 break;
 739                 case E820_RESERVED:
 740                                 printk("(reserved)\n");
 741                                 break;
 742                 case E820_ACPI:
 743                                 printk("(ACPI data)\n");
 744                                 break;
 745                 case E820_NVS:
 746                                 printk("(ACPI NVS)\n");
 747                                 break;
 748                 default:        printk("type %lu\n", e820.map[i].type);
 749                                 break;
 750                 }
 751         }
 752 }
 753
 754 static __init __always_inline void efi_limit_regions(unsigned long long size)
 755 {
 756         unsigned long long current_addr = 0;
 757         efi_memory_desc_t *md, *next_md;
 758         void *p, *p1;
 759         int i, j;
 760
 761         j = 0;
 762         p1 = memmap.map;
 763         for (p = p1, i = 0; p < memmap.map_end; p += memmap.desc_size, i++) {
 764                 md = p;
 765                 next_md = p1;
 766                 current_addr = md->phys_addr +
 767                         PFN_PHYS(md->num_pages);
 768                 if (is_available_memory(md)) {
 769                         if (md->phys_addr >= size) continue;
 770                         memcpy(next_md, md, memmap.desc_size);
 771                         if (current_addr >= size) {
 772                                 next_md->num_pages -=
 773                                         PFN_UP(current_addr-size);
 774                         }
 775                         p1 += memmap.desc_size;
 776                         next_md = p1;
 777                         j++;
 778                 } else if ((md->attribute & EFI_MEMORY_RUNTIME) ==
 779                            EFI_MEMORY_RUNTIME) {
 780                         /* In order to make runtime services
 781                          * available we have to include runtime
 782                          * memory regions in memory map */
 783                         memcpy(next_md, md, memmap.desc_size);
 784                         p1 += memmap.desc_size;
 785                         next_md = p1;
 786                         j++;
 787                 }
 788         }
 789         memmap.nr_map = j;
 790         memmap.map_end = memmap.map +
 791                 (memmap.nr_map * memmap.desc_size);
 792 }
 793
 794 void __init limit_regions(unsigned long long size)
 795 {
 796         unsigned long long current_addr;
 797         int i;
 798
 799         print_memory_map("limit_regions start");
 800         if (efi_enabled) {
 801                 efi_limit_regions(size);
 802                 return;
 803         }
 804         for (i = 0; i < e820.nr_map; i++) {
 805                 current_addr = e820.map[i].addr + e820.map[i].size;
 806                 if (current_addr < size)
 807                         continue;
 808
 809                 if (e820.map[i].type != E820_RAM)
 810                         continue;
 811
 812                 if (e820.map[i].addr >= size) {
 813                         /*
 814                          * This region starts past the end of the
 815                          * requested size, skip it completely.
 816                          */
 817                         e820.nr_map = i;
 818                 } else {
 819                         e820.nr_map = i + 1;
 820                         e820.map[i].size -= current_addr - size;
 821                 }
 822                 print_memory_map("limit_regions endfor");
 823                 return;
 824         }
 825         print_memory_map("limit_regions endfunc");
 826 }
 827
 828 /*
 829  * This function checks if any part of the range <start,end> is mapped
 830  * with type.
 831  */
 832 int
 833 e820_any_mapped(u64 start, u64 end, unsigned type)
 834 {
 835         int i;
 836         for (i = 0; i < e820.nr_map; i++) {
 837                 const struct e820entry *ei = &e820.map[i];
 838                 if (type && ei->type != type)
 839                         continue;
 840                 if (ei->addr >= end || ei->addr + ei->size <= start)
 841                         continue;
 842                 return 1;
 843         }
 844         return 0;
 845 }
 846 EXPORT_SYMBOL_GPL(e820_any_mapped);
 847
 848  /*
 849   * This function checks if the entire range <start,end> is mapped with type.
 850   *
 851   * Note: this function only works correct if the e820 table is sorted and
 852   * not-overlapping, which is the case
 853   */
 854 int __init
 855 e820_all_mapped(unsigned long s, unsigned long e, unsigned type)
 856 {
 857         u64 start = s;
 858         u64 end = e;
 859         int i;
 860         for (i = 0; i < e820.nr_map; i++) {
 861                 struct e820entry *ei = &e820.map[i];
 862                 if (type && ei->type != type)
 863                         continue;
 864                 /* is the region (part) in overlap with the current region ?*/
 865                 if (ei->addr >= end || ei->addr + ei->size <= start)
 866                         continue;
 867                 /* if the region is at the beginning of <start,end> we move
 868                  * start to the end of the region since it's ok until there
 869                  */
 870                 if (ei->addr <= start)
 871                         start = ei->addr + ei->size;
 872                 /* if start is now at or beyond end, we're done, full
 873                  * coverage */
 874                 if (start >= end)
 875                         return 1; /* we're done */
 876         }
 877         return 0;
 878 }
 879
 880 static int __init parse_memmap(char *arg)
 881 {
 882         if (!arg)
 883                 return -EINVAL;
 884
 885         if (strcmp(arg, "exactmap") == 0) {
 886 #ifdef CONFIG_CRASH_DUMP
 887                 /* If we are doing a crash dump, we
 888                  * still need to know the real mem
 889                  * size before original memory map is
 890                  * reset.
 891                  */
 892                 find_max_pfn();
 893                 saved_max_pfn = max_pfn;
 894 #endif
 895                 e820.nr_map = 0;
 896                 user_defined_memmap = 1;
 897         } else {
 898                 /* If the user specifies memory size, we
 899                  * limit the BIOS-provided memory map to
 900                  * that size. exactmap can be used to specify
 901                  * the exact map. mem=number can be used to
 902                  * trim the existing memory map.
 903                  */
 904                 unsigned long long start_at, mem_size;
 905
 906                 mem_size = memparse(arg, &arg);
 907                 if (*arg == '@') {
 908                         start_at = memparse(arg+1, &arg);
 909                         add_memory_region(start_at, mem_size, E820_RAM);
 910                 } else if (*arg == '#') {
 911                         start_at = memparse(arg+1, &arg);
 912                         add_memory_region(start_at, mem_size, E820_ACPI);
 913                 } else if (*arg == '$') {
 914                         start_at = memparse(arg+1, &arg);
 915                         add_memory_region(start_at, mem_size, E820_RESERVED);
 916                 } else {
 917                         limit_regions(mem_size);
 918                         user_defined_memmap = 1;
 919                 }
 920         }
 921         return 0;
 922 }
 923 early_param("memmap", parse_memmap);