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