arch/x86/kernel/e820_64.c

   1 /*
   2  * Handle the memory map.
   3  * The functions here do the job until bootmem takes over.
   4  *
   5  *  Getting sanitize_e820_map() in sync with i386 version by applying change:
   6  *  -  Provisions for empty E820 memory regions (reported by certain BIOSes).
   7  *     Alex Achenbach <xela@slit.de>, December 2002.
   8  *  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
   9  *
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/types.h>
  13 #include <linux/init.h>
  14 #include <linux/bootmem.h>
  15 #include <linux/ioport.h>
  16 #include <linux/string.h>
  17 #include <linux/kexec.h>
  18 #include <linux/module.h>
  19 #include <linux/mm.h>
  20 #include <linux/suspend.h>
  21 #include <linux/pfn.h>
  22
  23 #include <asm/pgtable.h>
  24 #include <asm/page.h>
  25 #include <asm/e820.h>
  26 #include <asm/proto.h>
  27 #include <asm/setup.h>
  28 #include <asm/sections.h>
  29 #include <asm/kdebug.h>
  30
  31 struct e820map e820;
  32
  33 /*
  34  * PFN of last memory page.
  35  */
  36 unsigned long end_pfn;
  37
  38 /*
  39  * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
  40  * The direct mapping extends to max_pfn_mapped, so that we can directly access
  41  * apertures, ACPI and other tables without having to play with fixmaps.
  42  */
  43 unsigned long max_pfn_mapped;
  44
  45 /*
  46  * Last pfn which the user wants to use.
  47  */
  48 static unsigned long __initdata end_user_pfn = MAXMEM>>PAGE_SHIFT;
  49
  50 /*
  51  * Early reserved memory areas.
  52  */
  53 #define MAX_EARLY_RES 20
  54
  55 struct early_res {
  56         unsigned long start, end;
  57         char name[16];
  58 };
  59 static struct early_res early_res[MAX_EARLY_RES] __initdata = {
  60         { 0, PAGE_SIZE, "BIOS data page" },                     /* BIOS data page */
  61 #ifdef CONFIG_SMP
  62         { SMP_TRAMPOLINE_BASE, SMP_TRAMPOLINE_BASE + 2*PAGE_SIZE, "SMP_TRAMPOLINE" },
  63 #endif
  64         {}
  65 };
  66
  67 void __init reserve_early(unsigned long start, unsigned long end, char *name)
  68 {
  69         int i;
  70         struct early_res *r;
  71         for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
  72                 r = &early_res[i];
  73                 if (end > r->start && start < r->end)
  74                         panic("Overlapping early reservations %lx-%lx %s to %lx-%lx %s\n",
  75                               start, end - 1, name?name:"", r->start, r->end - 1, r->name);
  76         }
  77         if (i >= MAX_EARLY_RES)
  78                 panic("Too many early reservations");
  79         r = &early_res[i];
  80         r->start = start;
  81         r->end = end;
  82         if (name)
  83                 strncpy(r->name, name, sizeof(r->name) - 1);
  84 }
  85
  86 void __init early_res_to_bootmem(void)
  87 {
  88         int i;
  89         for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
  90                 struct early_res *r = &early_res[i];
  91                 printk(KERN_INFO "early res: %d [%lx-%lx] %s\n", i,
  92                         r->start, r->end - 1, r->name);
  93                 reserve_bootmem_generic(r->start, r->end - r->start);
  94         }
  95 }
  96
  97 /* Check for already reserved areas */
  98 static inline int
  99 bad_addr(unsigned long *addrp, unsigned long size, unsigned long align)
 100 {
 101         int i;
 102         unsigned long addr = *addrp, last;
 103         int changed = 0;
 104 again:
 105         last = addr + size;
 106         for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
 107                 struct early_res *r = &early_res[i];
 108                 if (last >= r->start && addr < r->end) {
 109                         *addrp = addr = round_up(r->end, align);
 110                         changed = 1;
 111                         goto again;
 112                 }
 113         }
 114         return changed;
 115 }
 116
 117 /* Check for already reserved areas */
 118 static inline int
 119 bad_addr_size(unsigned long *addrp, unsigned long *sizep, unsigned long align)
 120 {
 121         int i;
 122         unsigned long addr = *addrp, last;
 123         unsigned long size = *sizep;
 124         int changed = 0;
 125 again:
 126         last = addr + size;
 127         for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
 128                 struct early_res *r = &early_res[i];
 129                 if (last > r->start && addr < r->start) {
 130                         size = r->start - addr;
 131                         changed = 1;
 132                         goto again;
 133                 }
 134                 if (last > r->end && addr < r->end) {
 135                         addr = round_up(r->end, align);
 136                         size = last - addr;
 137                         changed = 1;
 138                         goto again;
 139                 }
 140                 if (last <= r->end && addr >= r->start) {
 141                         (*sizep)++;
 142                         return 0;
 143                 }
 144         }
 145         if (changed) {
 146                 *addrp = addr;
 147                 *sizep = size;
 148         }
 149         return changed;
 150 }
 151 /*
 152  * This function checks if any part of the range <start,end> is mapped
 153  * with type.
 154  */
 155 int
 156 e820_any_mapped(unsigned long start, unsigned long end, unsigned type)
 157 {
 158         int i;
 159
 160         for (i = 0; i < e820.nr_map; i++) {
 161                 struct e820entry *ei = &e820.map[i];
 162
 163                 if (type && ei->type != type)
 164                         continue;
 165                 if (ei->addr >= end || ei->addr + ei->size <= start)
 166                         continue;
 167                 return 1;
 168         }
 169         return 0;
 170 }
 171 EXPORT_SYMBOL_GPL(e820_any_mapped);
 172
 173 /*
 174  * This function checks if the entire range <start,end> is mapped with type.
 175  *
 176  * Note: this function only works correct if the e820 table is sorted and
 177  * not-overlapping, which is the case
 178  */
 179 int __init e820_all_mapped(unsigned long start, unsigned long end,
 180                            unsigned type)
 181 {
 182         int i;
 183
 184         for (i = 0; i < e820.nr_map; i++) {
 185                 struct e820entry *ei = &e820.map[i];
 186
 187                 if (type && ei->type != type)
 188                         continue;
 189                 /* is the region (part) in overlap with the current region ?*/
 190                 if (ei->addr >= end || ei->addr + ei->size <= start)
 191                         continue;
 192
 193                 /* if the region is at the beginning of <start,end> we move
 194                  * start to the end of the region since it's ok until there
 195                  */
 196                 if (ei->addr <= start)
 197                         start = ei->addr + ei->size;
 198                 /*
 199                  * if start is now at or beyond end, we're done, full
 200                  * coverage
 201                  */
 202                 if (start >= end)
 203                         return 1;
 204         }
 205         return 0;
 206 }
 207
 208 /*
 209  * Find a free area with specified alignment in a specific range.
 210  */
 211 unsigned long __init find_e820_area(unsigned long start, unsigned long end,
 212                                     unsigned long size, unsigned long align)
 213 {
 214         int i;
 215
 216         for (i = 0; i < e820.nr_map; i++) {
 217                 struct e820entry *ei = &e820.map[i];
 218                 unsigned long addr, last;
 219                 unsigned long ei_last;
 220
 221                 if (ei->type != E820_RAM)
 222                         continue;
 223                 addr = round_up(ei->addr, align);
 224                 ei_last = ei->addr + ei->size;
 225                 if (addr < start)
 226                         addr = round_up(start, align);
 227                 if (addr >= ei_last)
 228                         continue;
 229                 while (bad_addr(&addr, size, align) && addr+size <= ei_last)
 230                         ;
 231                 last = addr + size;
 232                 if (last > ei_last)
 233                         continue;
 234                 if (last > end)
 235                         continue;
 236                 return addr;
 237         }
 238         return -1UL;
 239 }
 240
 241 /*
 242  * Find next free range after *start
 243  */
 244 unsigned long __init find_e820_area_size(unsigned long start,
 245                                          unsigned long *sizep,
 246                                          unsigned long align)
 247 {
 248         int i;
 249
 250         for (i = 0; i < e820.nr_map; i++) {
 251                 struct e820entry *ei = &e820.map[i];
 252                 unsigned long addr, last;
 253                 unsigned long ei_last;
 254
 255                 if (ei->type != E820_RAM)
 256                         continue;
 257                 addr = round_up(ei->addr, align);
 258                 ei_last = ei->addr + ei->size;
 259                 if (addr < start)
 260                         addr = round_up(start, align);
 261                 if (addr >= ei_last)
 262                         continue;
 263                 *sizep = ei_last - addr;
 264                 while (bad_addr_size(&addr, sizep, align) &&
 265                         addr + *sizep <= ei_last)
 266                         ;
 267                 last = addr + *sizep;
 268                 if (last > ei_last)
 269                         continue;
 270                 return addr;
 271         }
 272         return -1UL;
 273
 274 }
 275 /*
 276  * Find the highest page frame number we have available
 277  */
 278 unsigned long __init e820_end_of_ram(void)
 279 {
 280         unsigned long end_pfn;
 281
 282         end_pfn = find_max_pfn_with_active_regions();
 283
 284         if (end_pfn > max_pfn_mapped)
 285                 max_pfn_mapped = end_pfn;
 286         if (max_pfn_mapped > MAXMEM>>PAGE_SHIFT)
 287                 max_pfn_mapped = MAXMEM>>PAGE_SHIFT;
 288         if (end_pfn > end_user_pfn)
 289                 end_pfn = end_user_pfn;
 290         if (end_pfn > max_pfn_mapped)
 291                 end_pfn = max_pfn_mapped;
 292
 293         printk(KERN_INFO "max_pfn_mapped = %lu\n", max_pfn_mapped);
 294         return end_pfn;
 295 }
 296
 297 /*
 298  * Mark e820 reserved areas as busy for the resource manager.
 299  */
 300 void __init e820_reserve_resources(void)
 301 {
 302         int i;
 303         struct resource *res;
 304
 305         res = alloc_bootmem_low(sizeof(struct resource) * e820.nr_map);
 306         for (i = 0; i < e820.nr_map; i++) {
 307                 switch (e820.map[i].type) {
 308                 case E820_RAM:  res->name = "System RAM"; break;
 309                 case E820_ACPI: res->name = "ACPI Tables"; break;
 310                 case E820_NVS:  res->name = "ACPI Non-volatile Storage"; break;
 311                 default:        res->name = "reserved";
 312                 }
 313                 res->start = e820.map[i].addr;
 314                 res->end = res->start + e820.map[i].size - 1;
 315                 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 316                 insert_resource(&iomem_resource, res);
 317                 res++;
 318         }
 319 }
 320
 321 /*
 322  * Find the ranges of physical addresses that do not correspond to
 323  * e820 RAM areas and mark the corresponding pages as nosave for software
 324  * suspend and suspend to RAM.
 325  *
 326  * This function requires the e820 map to be sorted and without any
 327  * overlapping entries and assumes the first e820 area to be RAM.
 328  */
 329 void __init e820_mark_nosave_regions(void)
 330 {
 331         int i;
 332         unsigned long paddr;
 333
 334         paddr = round_down(e820.map[0].addr + e820.map[0].size, PAGE_SIZE);
 335         for (i = 1; i < e820.nr_map; i++) {
 336                 struct e820entry *ei = &e820.map[i];
 337
 338                 if (paddr < ei->addr)
 339                         register_nosave_region(PFN_DOWN(paddr),
 340                                                 PFN_UP(ei->addr));
 341
 342                 paddr = round_down(ei->addr + ei->size, PAGE_SIZE);
 343                 if (ei->type != E820_RAM)
 344                         register_nosave_region(PFN_UP(ei->addr),
 345                                                 PFN_DOWN(paddr));
 346
 347                 if (paddr >= (end_pfn << PAGE_SHIFT))
 348                         break;
 349         }
 350 }
 351
 352 /*
 353  * Finds an active region in the address range from start_pfn to end_pfn and
 354  * returns its range in ei_startpfn and ei_endpfn for the e820 entry.
 355  */
 356 static int __init e820_find_active_region(const struct e820entry *ei,
 357                                           unsigned long start_pfn,
 358                                           unsigned long end_pfn,
 359                                           unsigned long *ei_startpfn,
 360                                           unsigned long *ei_endpfn)
 361 {
 362         *ei_startpfn = round_up(ei->addr, PAGE_SIZE) >> PAGE_SHIFT;
 363         *ei_endpfn = round_down(ei->addr + ei->size, PAGE_SIZE) >> PAGE_SHIFT;
 364
 365         /* Skip map entries smaller than a page */
 366         if (*ei_startpfn >= *ei_endpfn)
 367                 return 0;
 368
 369         /* Check if max_pfn_mapped should be updated */
 370         if (ei->type != E820_RAM && *ei_endpfn > max_pfn_mapped)
 371                 max_pfn_mapped = *ei_endpfn;
 372
 373         /* Skip if map is outside the node */
 374         if (ei->type != E820_RAM || *ei_endpfn <= start_pfn ||
 375                                     *ei_startpfn >= end_pfn)
 376                 return 0;
 377
 378         /* Check for overlaps */
 379         if (*ei_startpfn < start_pfn)
 380                 *ei_startpfn = start_pfn;
 381         if (*ei_endpfn > end_pfn)
 382                 *ei_endpfn = end_pfn;
 383
 384         /* Obey end_user_pfn to save on memmap */
 385         if (*ei_startpfn >= end_user_pfn)
 386                 return 0;
 387         if (*ei_endpfn > end_user_pfn)
 388                 *ei_endpfn = end_user_pfn;
 389
 390         return 1;
 391 }
 392
 393 /* Walk the e820 map and register active regions within a node */
 394 void __init
 395 e820_register_active_regions(int nid, unsigned long start_pfn,
 396                                                         unsigned long end_pfn)
 397 {
 398         unsigned long ei_startpfn;
 399         unsigned long ei_endpfn;
 400         int i;
 401
 402         for (i = 0; i < e820.nr_map; i++)
 403                 if (e820_find_active_region(&e820.map[i],
 404                                             start_pfn, end_pfn,
 405                                             &ei_startpfn, &ei_endpfn))
 406                         add_active_range(nid, ei_startpfn, ei_endpfn);
 407 }
 408
 409 /*
 410  * Add a memory region to the kernel e820 map.
 411  */
 412 void __init add_memory_region(unsigned long start, unsigned long size, int type)
 413 {
 414         int x = e820.nr_map;
 415
 416         if (x == E820MAX) {
 417                 printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
 418                 return;
 419         }
 420
 421         e820.map[x].addr = start;
 422         e820.map[x].size = size;
 423         e820.map[x].type = type;
 424         e820.nr_map++;
 425 }
 426
 427 /*
 428  * Find the hole size (in bytes) in the memory range.
 429  * @start: starting address of the memory range to scan
 430  * @end: ending address of the memory range to scan
 431  */
 432 unsigned long __init e820_hole_size(unsigned long start, unsigned long end)
 433 {
 434         unsigned long start_pfn = start >> PAGE_SHIFT;
 435         unsigned long end_pfn = end >> PAGE_SHIFT;
 436         unsigned long ei_startpfn, ei_endpfn, ram = 0;
 437         int i;
 438
 439         for (i = 0; i < e820.nr_map; i++) {
 440                 if (e820_find_active_region(&e820.map[i],
 441                                             start_pfn, end_pfn,
 442                                             &ei_startpfn, &ei_endpfn))
 443                         ram += ei_endpfn - ei_startpfn;
 444         }
 445         return end - start - (ram << PAGE_SHIFT);
 446 }
 447
 448 static void __init e820_print_map(char *who)
 449 {
 450         int i;
 451
 452         for (i = 0; i < e820.nr_map; i++) {
 453                 printk(KERN_INFO " %s: %016Lx - %016Lx ", who,
 454                        (unsigned long long) e820.map[i].addr,
 455                        (unsigned long long)
 456                        (e820.map[i].addr + e820.map[i].size));
 457                 switch (e820.map[i].type) {
 458                 case E820_RAM:
 459                         printk(KERN_CONT "(usable)\n");
 460                         break;
 461                 case E820_RESERVED:
 462                         printk(KERN_CONT "(reserved)\n");
 463                         break;
 464                 case E820_ACPI:
 465                         printk(KERN_CONT "(ACPI data)\n");
 466                         break;
 467                 case E820_NVS:
 468                         printk(KERN_CONT "(ACPI NVS)\n");
 469                         break;
 470                 default:
 471                         printk(KERN_CONT "type %u\n", e820.map[i].type);
 472                         break;
 473                 }
 474         }
 475 }
 476
 477 /*
 478  * Sanitize the BIOS e820 map.
 479  *
 480  * Some e820 responses include overlapping entries. The following
 481  * replaces the original e820 map with a new one, removing overlaps.
 482  *
 483  */
 484 static int __init sanitize_e820_map(struct e820entry *biosmap, char *pnr_map)
 485 {
 486         struct change_member {
 487                 struct e820entry *pbios; /* pointer to original bios entry */
 488                 unsigned long long addr; /* address for this change point */
 489         };
 490         static struct change_member change_point_list[2*E820MAX] __initdata;
 491         static struct change_member *change_point[2*E820MAX] __initdata;
 492         static struct e820entry *overlap_list[E820MAX] __initdata;
 493         static struct e820entry new_bios[E820MAX] __initdata;
 494         struct change_member *change_tmp;
 495         unsigned long current_type, last_type;
 496         unsigned long long last_addr;
 497         int chgidx, still_changing;
 498         int overlap_entries;
 499         int new_bios_entry;
 500         int old_nr, new_nr, chg_nr;
 501         int i;
 502
 503         /*
 504                 Visually we're performing the following
 505                 (1,2,3,4 = memory types)...
 506
 507                 Sample memory map (w/overlaps):
 508                    ____22__________________
 509                    ______________________4_
 510                    ____1111________________
 511                    _44_____________________
 512                    11111111________________
 513                    ____________________33__
 514                    ___________44___________
 515                    __________33333_________
 516                    ______________22________
 517                    ___________________2222_
 518                    _________111111111______
 519                    _____________________11_
 520                    _________________4______
 521
 522                 Sanitized equivalent (no overlap):
 523                    1_______________________
 524                    _44_____________________
 525                    ___1____________________
 526                    ____22__________________
 527                    ______11________________
 528                    _________1______________
 529                    __________3_____________
 530                    ___________44___________
 531                    _____________33_________
 532                    _______________2________
 533                    ________________1_______
 534                    _________________4______
 535                    ___________________2____
 536                    ____________________33__
 537                    ______________________4_
 538         */
 539
 540         /* if there's only one memory region, don't bother */
 541         if (*pnr_map < 2)
 542                 return -1;
 543
 544         old_nr = *pnr_map;
 545
 546         /* bail out if we find any unreasonable addresses in bios map */
 547         for (i = 0; i < old_nr; i++)
 548                 if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
 549                         return -1;
 550
 551         /* create pointers for initial change-point information (for sorting) */
 552         for (i = 0; i < 2 * old_nr; i++)
 553                 change_point[i] = &change_point_list[i];
 554
 555         /* record all known change-points (starting and ending addresses),
 556            omitting those that are for empty memory regions */
 557         chgidx = 0;
 558         for (i = 0; i < old_nr; i++)    {
 559                 if (biosmap[i].size != 0) {
 560                         change_point[chgidx]->addr = biosmap[i].addr;
 561                         change_point[chgidx++]->pbios = &biosmap[i];
 562                         change_point[chgidx]->addr = biosmap[i].addr +
 563                                 biosmap[i].size;
 564                         change_point[chgidx++]->pbios = &biosmap[i];
 565                 }
 566         }
 567         chg_nr = chgidx;
 568
 569         /* sort change-point list by memory addresses (low -> high) */
 570         still_changing = 1;
 571         while (still_changing)  {
 572                 still_changing = 0;
 573                 for (i = 1; i < chg_nr; i++)  {
 574                         unsigned long long curaddr, lastaddr;
 575                         unsigned long long curpbaddr, lastpbaddr;
 576
 577                         curaddr = change_point[i]->addr;
 578                         lastaddr = change_point[i - 1]->addr;
 579                         curpbaddr = change_point[i]->pbios->addr;
 580                         lastpbaddr = change_point[i - 1]->pbios->addr;
 581
 582                         /*
 583                          * swap entries, when:
 584                          *
 585                          * curaddr > lastaddr or
 586                          * curaddr == lastaddr and curaddr == curpbaddr and
 587                          * lastaddr != lastpbaddr
 588                          */
 589                         if (curaddr < lastaddr ||
 590                             (curaddr == lastaddr && curaddr == curpbaddr &&
 591                              lastaddr != lastpbaddr)) {
 592                                 change_tmp = change_point[i];
 593                                 change_point[i] = change_point[i-1];
 594                                 change_point[i-1] = change_tmp;
 595                                 still_changing = 1;
 596                         }
 597                 }
 598         }
 599
 600         /* create a new bios memory map, removing overlaps */
 601         overlap_entries = 0;     /* number of entries in the overlap table */
 602         new_bios_entry = 0;      /* index for creating new bios map entries */
 603         last_type = 0;           /* start with undefined memory type */
 604         last_addr = 0;           /* start with 0 as last starting address */
 605
 606         /* loop through change-points, determining affect on the new bios map */
 607         for (chgidx = 0; chgidx < chg_nr; chgidx++) {
 608                 /* keep track of all overlapping bios entries */
 609                 if (change_point[chgidx]->addr ==
 610                     change_point[chgidx]->pbios->addr) {
 611                         /*
 612                          * add map entry to overlap list (> 1 entry
 613                          * implies an overlap)
 614                          */
 615                         overlap_list[overlap_entries++] =
 616                                 change_point[chgidx]->pbios;
 617                 } else {
 618                         /*
 619                          * remove entry from list (order independent,
 620                          * so swap with last)
 621                          */
 622                         for (i = 0; i < overlap_entries; i++) {
 623                                 if (overlap_list[i] ==
 624                                     change_point[chgidx]->pbios)
 625                                         overlap_list[i] =
 626                                                 overlap_list[overlap_entries-1];
 627                         }
 628                         overlap_entries--;
 629                 }
 630                 /*
 631                  * if there are overlapping entries, decide which
 632                  * "type" to use (larger value takes precedence --
 633                  * 1=usable, 2,3,4,4+=unusable)
 634                  */
 635                 current_type = 0;
 636                 for (i = 0; i < overlap_entries; i++)
 637                         if (overlap_list[i]->type > current_type)
 638                                 current_type = overlap_list[i]->type;
 639                 /*
 640                  * continue building up new bios map based on this
 641                  * information
 642                  */
 643                 if (current_type != last_type)  {
 644                         if (last_type != 0)      {
 645                                 new_bios[new_bios_entry].size =
 646                                         change_point[chgidx]->addr - last_addr;
 647                                 /*
 648                                  * move forward only if the new size
 649                                  * was non-zero
 650                                  */
 651                                 if (new_bios[new_bios_entry].size != 0)
 652                                         /*
 653                                          * no more space left for new
 654                                          * bios entries ?
 655                                          */
 656                                         if (++new_bios_entry >= E820MAX)
 657                                                 break;
 658                         }
 659                         if (current_type != 0)  {
 660                                 new_bios[new_bios_entry].addr =
 661                                         change_point[chgidx]->addr;
 662                                 new_bios[new_bios_entry].type = current_type;
 663                                 last_addr = change_point[chgidx]->addr;
 664                         }
 665                         last_type = current_type;
 666                 }
 667         }
 668         /* retain count for new bios entries */
 669         new_nr = new_bios_entry;
 670
 671         /* copy new bios mapping into original location */
 672         memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
 673         *pnr_map = new_nr;
 674
 675         return 0;
 676 }
 677
 678 /*
 679  * Copy the BIOS e820 map into a safe place.
 680  *
 681  * Sanity-check it while we're at it..
 682  *
 683  * If we're lucky and live on a modern system, the setup code
 684  * will have given us a memory map that we can use to properly
 685  * set up memory.  If we aren't, we'll fake a memory map.
 686  */
 687 static int __init copy_e820_map(struct e820entry *biosmap, int nr_map)
 688 {
 689         /* Only one memory region (or negative)? Ignore it */
 690         if (nr_map < 2)
 691                 return -1;
 692
 693         do {
 694                 u64 start = biosmap->addr;
 695                 u64 size = biosmap->size;
 696                 u64 end = start + size;
 697                 u32 type = biosmap->type;
 698
 699                 /* Overflow in 64 bits? Ignore the memory map. */
 700                 if (start > end)
 701                         return -1;
 702
 703                 add_memory_region(start, size, type);
 704         } while (biosmap++, --nr_map);
 705         return 0;
 706 }
 707
 708 static void early_panic(char *msg)
 709 {
 710         early_printk(msg);
 711         panic(msg);
 712 }
 713
 714 /* We're not void only for x86 32-bit compat */
 715 char * __init machine_specific_memory_setup(void)
 716 {
 717         char *who = "BIOS-e820";
 718         /*
 719          * Try to copy the BIOS-supplied E820-map.
 720          *
 721          * Otherwise fake a memory map; one section from 0k->640k,
 722          * the next section from 1mb->appropriate_mem_k
 723          */
 724         sanitize_e820_map(boot_params.e820_map, &boot_params.e820_entries);
 725         if (copy_e820_map(boot_params.e820_map, boot_params.e820_entries) < 0)
 726                 early_panic("Cannot find a valid memory map");
 727         printk(KERN_INFO "BIOS-provided physical RAM map:\n");
 728         e820_print_map(who);
 729
 730         /* In case someone cares... */
 731         return who;
 732 }
 733
 734 static int __init parse_memopt(char *p)
 735 {
 736         if (!p)
 737                 return -EINVAL;
 738         end_user_pfn = memparse(p, &p);
 739         end_user_pfn >>= PAGE_SHIFT;
 740         return 0;
 741 }
 742 early_param("mem", parse_memopt);
 743
 744 static int userdef __initdata;
 745
 746 static int __init parse_memmap_opt(char *p)
 747 {
 748         char *oldp;
 749         unsigned long long start_at, mem_size;
 750
 751         if (!strcmp(p, "exactmap")) {
 752 #ifdef CONFIG_CRASH_DUMP
 753                 /*
 754                  * If we are doing a crash dump, we still need to know
 755                  * the real mem size before original memory map is
 756                  * reset.
 757                  */
 758                 e820_register_active_regions(0, 0, -1UL);
 759                 saved_max_pfn = e820_end_of_ram();
 760                 remove_all_active_ranges();
 761 #endif
 762                 max_pfn_mapped = 0;
 763                 e820.nr_map = 0;
 764                 userdef = 1;
 765                 return 0;
 766         }
 767
 768         oldp = p;
 769         mem_size = memparse(p, &p);
 770         if (p == oldp)
 771                 return -EINVAL;
 772
 773         userdef = 1;
 774         if (*p == '@') {
 775                 start_at = memparse(p+1, &p);
 776                 add_memory_region(start_at, mem_size, E820_RAM);
 777         } else if (*p == '#') {
 778                 start_at = memparse(p+1, &p);
 779                 add_memory_region(start_at, mem_size, E820_ACPI);
 780         } else if (*p == '$') {
 781                 start_at = memparse(p+1, &p);
 782                 add_memory_region(start_at, mem_size, E820_RESERVED);
 783         } else {
 784                 end_user_pfn = (mem_size >> PAGE_SHIFT);
 785         }
 786         return *p == '\0' ? 0 : -EINVAL;
 787 }
 788 early_param("memmap", parse_memmap_opt);
 789
 790 void __init finish_e820_parsing(void)
 791 {
 792         if (userdef) {
 793                 char nr = e820.nr_map;
 794
 795                 if (sanitize_e820_map(e820.map, &nr) < 0)
 796                         early_panic("Invalid user supplied memory map");
 797                 e820.nr_map = nr;
 798
 799                 printk(KERN_INFO "user-defined physical RAM map:\n");
 800                 e820_print_map("user");
 801         }
 802 }
 803
 804 void __init update_memory_range(u64 start, u64 size, unsigned old_type,
 805                                 unsigned new_type)
 806 {
 807         int i;
 808
 809         BUG_ON(old_type == new_type);
 810
 811         for (i = 0; i < e820.nr_map; i++) {
 812                 struct e820entry *ei = &e820.map[i];
 813                 u64 final_start, final_end;
 814                 if (ei->type != old_type)
 815                         continue;
 816                 /* totally covered? */
 817                 if (ei->addr >= start && ei->size <= size) {
 818                         ei->type = new_type;
 819                         continue;
 820                 }
 821                 /* partially covered */
 822                 final_start = max(start, ei->addr);
 823                 final_end = min(start + size, ei->addr + ei->size);
 824                 if (final_start >= final_end)
 825                         continue;
 826                 add_memory_region(final_start, final_end - final_start,
 827                                          new_type);
 828         }
 829 }
 830
 831 void __init update_e820(void)
 832 {
 833         u8 nr_map;
 834
 835         nr_map = e820.nr_map;
 836         if (sanitize_e820_map(e820.map, &nr_map))
 837                 return;
 838         e820.nr_map = nr_map;
 839         printk(KERN_INFO "modified physical RAM map:\n");
 840         e820_print_map("modified");
 841 }
 842
 843 unsigned long pci_mem_start = 0xaeedbabe;
 844 EXPORT_SYMBOL(pci_mem_start);
 845
 846 /*
 847  * Search for the biggest gap in the low 32 bits of the e820
 848  * memory space.  We pass this space to PCI to assign MMIO resources
 849  * for hotplug or unconfigured devices in.
 850  * Hopefully the BIOS let enough space left.
 851  */
 852 __init void e820_setup_gap(void)
 853 {
 854         unsigned long gapstart, gapsize, round;
 855         unsigned long last;
 856         int i;
 857         int found = 0;
 858
 859         last = 0x100000000ull;
 860         gapstart = 0x10000000;
 861         gapsize = 0x400000;
 862         i = e820.nr_map;
 863         while (--i >= 0) {
 864                 unsigned long long start = e820.map[i].addr;
 865                 unsigned long long end = start + e820.map[i].size;
 866
 867                 /*
 868                  * Since "last" is at most 4GB, we know we'll
 869                  * fit in 32 bits if this condition is true
 870                  */
 871                 if (last > end) {
 872                         unsigned long gap = last - end;
 873
 874                         if (gap > gapsize) {
 875                                 gapsize = gap;
 876                                 gapstart = end;
 877                                 found = 1;
 878                         }
 879                 }
 880                 if (start < last)
 881                         last = start;
 882         }
 883
 884         if (!found) {
 885                 gapstart = (end_pfn << PAGE_SHIFT) + 1024*1024;
 886                 printk(KERN_ERR "PCI: Warning: Cannot find a gap in the 32bit "
 887                        "address range\n"
 888                        KERN_ERR "PCI: Unassigned devices with 32bit resource "
 889                        "registers may break!\n");
 890         }
 891
 892         /*
 893          * See how much we want to round up: start off with
 894          * rounding to the next 1MB area.
 895          */
 896         round = 0x100000;
 897         while ((gapsize >> 4) > round)
 898                 round += round;
 899         /* Fun with two's complement */
 900         pci_mem_start = (gapstart + round) & -round;
 901
 902         printk(KERN_INFO
 903                "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
 904                pci_mem_start, gapstart, gapsize);
 905 }
 906
 907 int __init arch_get_ram_range(int slot, u64 *addr, u64 *size)
 908 {
 909         int i;
 910
 911         if (slot < 0 || slot >= e820.nr_map)
 912                 return -1;
 913         for (i = slot; i < e820.nr_map; i++) {
 914                 if (e820.map[i].type != E820_RAM)
 915                         continue;
 916                 break;
 917         }
 918         if (i == e820.nr_map || e820.map[i].addr > (max_pfn << PAGE_SHIFT))
 919                 return -1;
 920         *addr = e820.map[i].addr;
 921         *size = min_t(u64, e820.map[i].size + e820.map[i].addr,
 922                 max_pfn << PAGE_SHIFT) - *addr;
 923         return i + 1;
 924 }