linux/arch/x86/kernel/e820.c
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   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/crash_dump.h>
  15#include <linux/export.h>
  16#include <linux/bootmem.h>
  17#include <linux/pfn.h>
  18#include <linux/suspend.h>
  19#include <linux/acpi.h>
  20#include <linux/firmware-map.h>
  21#include <linux/memblock.h>
  22#include <linux/sort.h>
  23
  24#include <asm/e820.h>
  25#include <asm/proto.h>
  26#include <asm/setup.h>
  27
  28/*
  29 * The e820 map is the map that gets modified e.g. with command line parameters
  30 * and that is also registered with modifications in the kernel resource tree
  31 * with the iomem_resource as parent.
  32 *
  33 * The e820_saved is directly saved after the BIOS-provided memory map is
  34 * copied. It doesn't get modified afterwards. It's registered for the
  35 * /sys/firmware/memmap interface.
  36 *
  37 * That memory map is not modified and is used as base for kexec. The kexec'd
  38 * kernel should get the same memory map as the firmware provides. Then the
  39 * user can e.g. boot the original kernel with mem=1G while still booting the
  40 * next kernel with full memory.
  41 */
  42struct e820map e820;
  43struct e820map e820_saved;
  44
  45/* For PCI or other memory-mapped resources */
  46unsigned long pci_mem_start = 0xaeedbabe;
  47#ifdef CONFIG_PCI
  48EXPORT_SYMBOL(pci_mem_start);
  49#endif
  50
  51/*
  52 * This function checks if any part of the range <start,end> is mapped
  53 * with type.
  54 */
  55int
  56e820_any_mapped(u64 start, u64 end, unsigned type)
  57{
  58        int i;
  59
  60        for (i = 0; i < e820.nr_map; i++) {
  61                struct e820entry *ei = &e820.map[i];
  62
  63                if (type && ei->type != type)
  64                        continue;
  65                if (ei->addr >= end || ei->addr + ei->size <= start)
  66                        continue;
  67                return 1;
  68        }
  69        return 0;
  70}
  71EXPORT_SYMBOL_GPL(e820_any_mapped);
  72
  73/*
  74 * This function checks if the entire range <start,end> is mapped with type.
  75 *
  76 * Note: this function only works correct if the e820 table is sorted and
  77 * not-overlapping, which is the case
  78 */
  79int __init e820_all_mapped(u64 start, u64 end, unsigned type)
  80{
  81        int i;
  82
  83        for (i = 0; i < e820.nr_map; i++) {
  84                struct e820entry *ei = &e820.map[i];
  85
  86                if (type && ei->type != type)
  87                        continue;
  88                /* is the region (part) in overlap with the current region ?*/
  89                if (ei->addr >= end || ei->addr + ei->size <= start)
  90                        continue;
  91
  92                /* if the region is at the beginning of <start,end> we move
  93                 * start to the end of the region since it's ok until there
  94                 */
  95                if (ei->addr <= start)
  96                        start = ei->addr + ei->size;
  97                /*
  98                 * if start is now at or beyond end, we're done, full
  99                 * coverage
 100                 */
 101                if (start >= end)
 102                        return 1;
 103        }
 104        return 0;
 105}
 106
 107/*
 108 * Add a memory region to the kernel e820 map.
 109 */
 110static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size,
 111                                         int type)
 112{
 113        int x = e820x->nr_map;
 114
 115        if (x >= ARRAY_SIZE(e820x->map)) {
 116                printk(KERN_ERR "e820: too many entries; ignoring [mem %#010llx-%#010llx]\n",
 117                       (unsigned long long) start,
 118                       (unsigned long long) (start + size - 1));
 119                return;
 120        }
 121
 122        e820x->map[x].addr = start;
 123        e820x->map[x].size = size;
 124        e820x->map[x].type = type;
 125        e820x->nr_map++;
 126}
 127
 128void __init e820_add_region(u64 start, u64 size, int type)
 129{
 130        __e820_add_region(&e820, start, size, type);
 131}
 132
 133static void __init e820_print_type(u32 type)
 134{
 135        switch (type) {
 136        case E820_RAM:
 137        case E820_RESERVED_KERN:
 138                printk(KERN_CONT "usable");
 139                break;
 140        case E820_RESERVED:
 141                printk(KERN_CONT "reserved");
 142                break;
 143        case E820_ACPI:
 144                printk(KERN_CONT "ACPI data");
 145                break;
 146        case E820_NVS:
 147                printk(KERN_CONT "ACPI NVS");
 148                break;
 149        case E820_UNUSABLE:
 150                printk(KERN_CONT "unusable");
 151                break;
 152        default:
 153                printk(KERN_CONT "type %u", type);
 154                break;
 155        }
 156}
 157
 158void __init e820_print_map(char *who)
 159{
 160        int i;
 161
 162        for (i = 0; i < e820.nr_map; i++) {
 163                printk(KERN_INFO "%s: [mem %#018Lx-%#018Lx] ", who,
 164                       (unsigned long long) e820.map[i].addr,
 165                       (unsigned long long)
 166                       (e820.map[i].addr + e820.map[i].size - 1));
 167                e820_print_type(e820.map[i].type);
 168                printk(KERN_CONT "\n");
 169        }
 170}
 171
 172/*
 173 * Sanitize the BIOS e820 map.
 174 *
 175 * Some e820 responses include overlapping entries. The following
 176 * replaces the original e820 map with a new one, removing overlaps,
 177 * and resolving conflicting memory types in favor of highest
 178 * numbered type.
 179 *
 180 * The input parameter biosmap points to an array of 'struct
 181 * e820entry' which on entry has elements in the range [0, *pnr_map)
 182 * valid, and which has space for up to max_nr_map entries.
 183 * On return, the resulting sanitized e820 map entries will be in
 184 * overwritten in the same location, starting at biosmap.
 185 *
 186 * The integer pointed to by pnr_map must be valid on entry (the
 187 * current number of valid entries located at biosmap) and will
 188 * be updated on return, with the new number of valid entries
 189 * (something no more than max_nr_map.)
 190 *
 191 * The return value from sanitize_e820_map() is zero if it
 192 * successfully 'sanitized' the map entries passed in, and is -1
 193 * if it did nothing, which can happen if either of (1) it was
 194 * only passed one map entry, or (2) any of the input map entries
 195 * were invalid (start + size < start, meaning that the size was
 196 * so big the described memory range wrapped around through zero.)
 197 *
 198 *      Visually we're performing the following
 199 *      (1,2,3,4 = memory types)...
 200 *
 201 *      Sample memory map (w/overlaps):
 202 *         ____22__________________
 203 *         ______________________4_
 204 *         ____1111________________
 205 *         _44_____________________
 206 *         11111111________________
 207 *         ____________________33__
 208 *         ___________44___________
 209 *         __________33333_________
 210 *         ______________22________
 211 *         ___________________2222_
 212 *         _________111111111______
 213 *         _____________________11_
 214 *         _________________4______
 215 *
 216 *      Sanitized equivalent (no overlap):
 217 *         1_______________________
 218 *         _44_____________________
 219 *         ___1____________________
 220 *         ____22__________________
 221 *         ______11________________
 222 *         _________1______________
 223 *         __________3_____________
 224 *         ___________44___________
 225 *         _____________33_________
 226 *         _______________2________
 227 *         ________________1_______
 228 *         _________________4______
 229 *         ___________________2____
 230 *         ____________________33__
 231 *         ______________________4_
 232 */
 233struct change_member {
 234        struct e820entry *pbios; /* pointer to original bios entry */
 235        unsigned long long addr; /* address for this change point */
 236};
 237
 238static int __init cpcompare(const void *a, const void *b)
 239{
 240        struct change_member * const *app = a, * const *bpp = b;
 241        const struct change_member *ap = *app, *bp = *bpp;
 242
 243        /*
 244         * Inputs are pointers to two elements of change_point[].  If their
 245         * addresses are unequal, their difference dominates.  If the addresses
 246         * are equal, then consider one that represents the end of its region
 247         * to be greater than one that does not.
 248         */
 249        if (ap->addr != bp->addr)
 250                return ap->addr > bp->addr ? 1 : -1;
 251
 252        return (ap->addr != ap->pbios->addr) - (bp->addr != bp->pbios->addr);
 253}
 254
 255int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
 256                             u32 *pnr_map)
 257{
 258        static struct change_member change_point_list[2*E820_X_MAX] __initdata;
 259        static struct change_member *change_point[2*E820_X_MAX] __initdata;
 260        static struct e820entry *overlap_list[E820_X_MAX] __initdata;
 261        static struct e820entry new_bios[E820_X_MAX] __initdata;
 262        unsigned long current_type, last_type;
 263        unsigned long long last_addr;
 264        int chgidx;
 265        int overlap_entries;
 266        int new_bios_entry;
 267        int old_nr, new_nr, chg_nr;
 268        int i;
 269
 270        /* if there's only one memory region, don't bother */
 271        if (*pnr_map < 2)
 272                return -1;
 273
 274        old_nr = *pnr_map;
 275        BUG_ON(old_nr > max_nr_map);
 276
 277        /* bail out if we find any unreasonable addresses in bios map */
 278        for (i = 0; i < old_nr; i++)
 279                if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
 280                        return -1;
 281
 282        /* create pointers for initial change-point information (for sorting) */
 283        for (i = 0; i < 2 * old_nr; i++)
 284                change_point[i] = &change_point_list[i];
 285
 286        /* record all known change-points (starting and ending addresses),
 287           omitting those that are for empty memory regions */
 288        chgidx = 0;
 289        for (i = 0; i < old_nr; i++)    {
 290                if (biosmap[i].size != 0) {
 291                        change_point[chgidx]->addr = biosmap[i].addr;
 292                        change_point[chgidx++]->pbios = &biosmap[i];
 293                        change_point[chgidx]->addr = biosmap[i].addr +
 294                                biosmap[i].size;
 295                        change_point[chgidx++]->pbios = &biosmap[i];
 296                }
 297        }
 298        chg_nr = chgidx;
 299
 300        /* sort change-point list by memory addresses (low -> high) */
 301        sort(change_point, chg_nr, sizeof *change_point, cpcompare, NULL);
 302
 303        /* create a new bios memory map, removing overlaps */
 304        overlap_entries = 0;     /* number of entries in the overlap table */
 305        new_bios_entry = 0;      /* index for creating new bios map entries */
 306        last_type = 0;           /* start with undefined memory type */
 307        last_addr = 0;           /* start with 0 as last starting address */
 308
 309        /* loop through change-points, determining affect on the new bios map */
 310        for (chgidx = 0; chgidx < chg_nr; chgidx++) {
 311                /* keep track of all overlapping bios entries */
 312                if (change_point[chgidx]->addr ==
 313                    change_point[chgidx]->pbios->addr) {
 314                        /*
 315                         * add map entry to overlap list (> 1 entry
 316                         * implies an overlap)
 317                         */
 318                        overlap_list[overlap_entries++] =
 319                                change_point[chgidx]->pbios;
 320                } else {
 321                        /*
 322                         * remove entry from list (order independent,
 323                         * so swap with last)
 324                         */
 325                        for (i = 0; i < overlap_entries; i++) {
 326                                if (overlap_list[i] ==
 327                                    change_point[chgidx]->pbios)
 328                                        overlap_list[i] =
 329                                                overlap_list[overlap_entries-1];
 330                        }
 331                        overlap_entries--;
 332                }
 333                /*
 334                 * if there are overlapping entries, decide which
 335                 * "type" to use (larger value takes precedence --
 336                 * 1=usable, 2,3,4,4+=unusable)
 337                 */
 338                current_type = 0;
 339                for (i = 0; i < overlap_entries; i++)
 340                        if (overlap_list[i]->type > current_type)
 341                                current_type = overlap_list[i]->type;
 342                /*
 343                 * continue building up new bios map based on this
 344                 * information
 345                 */
 346                if (current_type != last_type)  {
 347                        if (last_type != 0)      {
 348                                new_bios[new_bios_entry].size =
 349                                        change_point[chgidx]->addr - last_addr;
 350                                /*
 351                                 * move forward only if the new size
 352                                 * was non-zero
 353                                 */
 354                                if (new_bios[new_bios_entry].size != 0)
 355                                        /*
 356                                         * no more space left for new
 357                                         * bios entries ?
 358                                         */
 359                                        if (++new_bios_entry >= max_nr_map)
 360                                                break;
 361                        }
 362                        if (current_type != 0)  {
 363                                new_bios[new_bios_entry].addr =
 364                                        change_point[chgidx]->addr;
 365                                new_bios[new_bios_entry].type = current_type;
 366                                last_addr = change_point[chgidx]->addr;
 367                        }
 368                        last_type = current_type;
 369                }
 370        }
 371        /* retain count for new bios entries */
 372        new_nr = new_bios_entry;
 373
 374        /* copy new bios mapping into original location */
 375        memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
 376        *pnr_map = new_nr;
 377
 378        return 0;
 379}
 380
 381static int __init __append_e820_map(struct e820entry *biosmap, int nr_map)
 382{
 383        while (nr_map) {
 384                u64 start = biosmap->addr;
 385                u64 size = biosmap->size;
 386                u64 end = start + size;
 387                u32 type = biosmap->type;
 388
 389                /* Overflow in 64 bits? Ignore the memory map. */
 390                if (start > end)
 391                        return -1;
 392
 393                e820_add_region(start, size, type);
 394
 395                biosmap++;
 396                nr_map--;
 397        }
 398        return 0;
 399}
 400
 401/*
 402 * Copy the BIOS e820 map into a safe place.
 403 *
 404 * Sanity-check it while we're at it..
 405 *
 406 * If we're lucky and live on a modern system, the setup code
 407 * will have given us a memory map that we can use to properly
 408 * set up memory.  If we aren't, we'll fake a memory map.
 409 */
 410static int __init append_e820_map(struct e820entry *biosmap, int nr_map)
 411{
 412        /* Only one memory region (or negative)? Ignore it */
 413        if (nr_map < 2)
 414                return -1;
 415
 416        return __append_e820_map(biosmap, nr_map);
 417}
 418
 419static u64 __init __e820_update_range(struct e820map *e820x, u64 start,
 420                                        u64 size, unsigned old_type,
 421                                        unsigned new_type)
 422{
 423        u64 end;
 424        unsigned int i;
 425        u64 real_updated_size = 0;
 426
 427        BUG_ON(old_type == new_type);
 428
 429        if (size > (ULLONG_MAX - start))
 430                size = ULLONG_MAX - start;
 431
 432        end = start + size;
 433        printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ",
 434               (unsigned long long) start, (unsigned long long) (end - 1));
 435        e820_print_type(old_type);
 436        printk(KERN_CONT " ==> ");
 437        e820_print_type(new_type);
 438        printk(KERN_CONT "\n");
 439
 440        for (i = 0; i < e820x->nr_map; i++) {
 441                struct e820entry *ei = &e820x->map[i];
 442                u64 final_start, final_end;
 443                u64 ei_end;
 444
 445                if (ei->type != old_type)
 446                        continue;
 447
 448                ei_end = ei->addr + ei->size;
 449                /* totally covered by new range? */
 450                if (ei->addr >= start && ei_end <= end) {
 451                        ei->type = new_type;
 452                        real_updated_size += ei->size;
 453                        continue;
 454                }
 455
 456                /* new range is totally covered? */
 457                if (ei->addr < start && ei_end > end) {
 458                        __e820_add_region(e820x, start, size, new_type);
 459                        __e820_add_region(e820x, end, ei_end - end, ei->type);
 460                        ei->size = start - ei->addr;
 461                        real_updated_size += size;
 462                        continue;
 463                }
 464
 465                /* partially covered */
 466                final_start = max(start, ei->addr);
 467                final_end = min(end, ei_end);
 468                if (final_start >= final_end)
 469                        continue;
 470
 471                __e820_add_region(e820x, final_start, final_end - final_start,
 472                                  new_type);
 473
 474                real_updated_size += final_end - final_start;
 475
 476                /*
 477                 * left range could be head or tail, so need to update
 478                 * size at first.
 479                 */
 480                ei->size -= final_end - final_start;
 481                if (ei->addr < final_start)
 482                        continue;
 483                ei->addr = final_end;
 484        }
 485        return real_updated_size;
 486}
 487
 488u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
 489                             unsigned new_type)
 490{
 491        return __e820_update_range(&e820, start, size, old_type, new_type);
 492}
 493
 494static u64 __init e820_update_range_saved(u64 start, u64 size,
 495                                          unsigned old_type, unsigned new_type)
 496{
 497        return __e820_update_range(&e820_saved, start, size, old_type,
 498                                     new_type);
 499}
 500
 501/* make e820 not cover the range */
 502u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
 503                             int checktype)
 504{
 505        int i;
 506        u64 end;
 507        u64 real_removed_size = 0;
 508
 509        if (size > (ULLONG_MAX - start))
 510                size = ULLONG_MAX - start;
 511
 512        end = start + size;
 513        printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ",
 514               (unsigned long long) start, (unsigned long long) (end - 1));
 515        if (checktype)
 516                e820_print_type(old_type);
 517        printk(KERN_CONT "\n");
 518
 519        for (i = 0; i < e820.nr_map; i++) {
 520                struct e820entry *ei = &e820.map[i];
 521                u64 final_start, final_end;
 522                u64 ei_end;
 523
 524                if (checktype && ei->type != old_type)
 525                        continue;
 526
 527                ei_end = ei->addr + ei->size;
 528                /* totally covered? */
 529                if (ei->addr >= start && ei_end <= end) {
 530                        real_removed_size += ei->size;
 531                        memset(ei, 0, sizeof(struct e820entry));
 532                        continue;
 533                }
 534
 535                /* new range is totally covered? */
 536                if (ei->addr < start && ei_end > end) {
 537                        e820_add_region(end, ei_end - end, ei->type);
 538                        ei->size = start - ei->addr;
 539                        real_removed_size += size;
 540                        continue;
 541                }
 542
 543                /* partially covered */
 544                final_start = max(start, ei->addr);
 545                final_end = min(end, ei_end);
 546                if (final_start >= final_end)
 547                        continue;
 548                real_removed_size += final_end - final_start;
 549
 550                /*
 551                 * left range could be head or tail, so need to update
 552                 * size at first.
 553                 */
 554                ei->size -= final_end - final_start;
 555                if (ei->addr < final_start)
 556                        continue;
 557                ei->addr = final_end;
 558        }
 559        return real_removed_size;
 560}
 561
 562void __init update_e820(void)
 563{
 564        u32 nr_map;
 565
 566        nr_map = e820.nr_map;
 567        if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))
 568                return;
 569        e820.nr_map = nr_map;
 570        printk(KERN_INFO "e820: modified physical RAM map:\n");
 571        e820_print_map("modified");
 572}
 573static void __init update_e820_saved(void)
 574{
 575        u32 nr_map;
 576
 577        nr_map = e820_saved.nr_map;
 578        if (sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map), &nr_map))
 579                return;
 580        e820_saved.nr_map = nr_map;
 581}
 582#define MAX_GAP_END 0x100000000ull
 583/*
 584 * Search for a gap in the e820 memory space from start_addr to end_addr.
 585 */
 586__init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,
 587                unsigned long start_addr, unsigned long long end_addr)
 588{
 589        unsigned long long last;
 590        int i = e820.nr_map;
 591        int found = 0;
 592
 593        last = (end_addr && end_addr < MAX_GAP_END) ? end_addr : MAX_GAP_END;
 594
 595        while (--i >= 0) {
 596                unsigned long long start = e820.map[i].addr;
 597                unsigned long long end = start + e820.map[i].size;
 598
 599                if (end < start_addr)
 600                        continue;
 601
 602                /*
 603                 * Since "last" is at most 4GB, we know we'll
 604                 * fit in 32 bits if this condition is true
 605                 */
 606                if (last > end) {
 607                        unsigned long gap = last - end;
 608
 609                        if (gap >= *gapsize) {
 610                                *gapsize = gap;
 611                                *gapstart = end;
 612                                found = 1;
 613                        }
 614                }
 615                if (start < last)
 616                        last = start;
 617        }
 618        return found;
 619}
 620
 621/*
 622 * Search for the biggest gap in the low 32 bits of the e820
 623 * memory space.  We pass this space to PCI to assign MMIO resources
 624 * for hotplug or unconfigured devices in.
 625 * Hopefully the BIOS let enough space left.
 626 */
 627__init void e820_setup_gap(void)
 628{
 629        unsigned long gapstart, gapsize;
 630        int found;
 631
 632        gapstart = 0x10000000;
 633        gapsize = 0x400000;
 634        found  = e820_search_gap(&gapstart, &gapsize, 0, MAX_GAP_END);
 635
 636#ifdef CONFIG_X86_64
 637        if (!found) {
 638                gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
 639                printk(KERN_ERR
 640        "e820: cannot find a gap in the 32bit address range\n"
 641        "e820: PCI devices with unassigned 32bit BARs may break!\n");
 642        }
 643#endif
 644
 645        /*
 646         * e820_reserve_resources_late protect stolen RAM already
 647         */
 648        pci_mem_start = gapstart;
 649
 650        printk(KERN_INFO
 651               "e820: [mem %#010lx-%#010lx] available for PCI devices\n",
 652               gapstart, gapstart + gapsize - 1);
 653}
 654
 655/**
 656 * Because of the size limitation of struct boot_params, only first
 657 * 128 E820 memory entries are passed to kernel via
 658 * boot_params.e820_map, others are passed via SETUP_E820_EXT node of
 659 * linked list of struct setup_data, which is parsed here.
 660 */
 661void __init parse_e820_ext(struct setup_data *sdata)
 662{
 663        int entries;
 664        struct e820entry *extmap;
 665
 666        entries = sdata->len / sizeof(struct e820entry);
 667        extmap = (struct e820entry *)(sdata->data);
 668        __append_e820_map(extmap, entries);
 669        sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 670        printk(KERN_INFO "e820: extended physical RAM map:\n");
 671        e820_print_map("extended");
 672}
 673
 674#if defined(CONFIG_X86_64) || \
 675        (defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
 676/**
 677 * Find the ranges of physical addresses that do not correspond to
 678 * e820 RAM areas and mark the corresponding pages as nosave for
 679 * hibernation (32 bit) or software suspend and suspend to RAM (64 bit).
 680 *
 681 * This function requires the e820 map to be sorted and without any
 682 * overlapping entries and assumes the first e820 area to be RAM.
 683 */
 684void __init e820_mark_nosave_regions(unsigned long limit_pfn)
 685{
 686        int i;
 687        unsigned long pfn;
 688
 689        pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size);
 690        for (i = 1; i < e820.nr_map; i++) {
 691                struct e820entry *ei = &e820.map[i];
 692
 693                if (pfn < PFN_UP(ei->addr))
 694                        register_nosave_region(pfn, PFN_UP(ei->addr));
 695
 696                pfn = PFN_DOWN(ei->addr + ei->size);
 697                if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
 698                        register_nosave_region(PFN_UP(ei->addr), pfn);
 699
 700                if (pfn >= limit_pfn)
 701                        break;
 702        }
 703}
 704#endif
 705
 706#ifdef CONFIG_ACPI
 707/**
 708 * Mark ACPI NVS memory region, so that we can save/restore it during
 709 * hibernation and the subsequent resume.
 710 */
 711static int __init e820_mark_nvs_memory(void)
 712{
 713        int i;
 714
 715        for (i = 0; i < e820.nr_map; i++) {
 716                struct e820entry *ei = &e820.map[i];
 717
 718                if (ei->type == E820_NVS)
 719                        acpi_nvs_register(ei->addr, ei->size);
 720        }
 721
 722        return 0;
 723}
 724core_initcall(e820_mark_nvs_memory);
 725#endif
 726
 727/*
 728 * pre allocated 4k and reserved it in memblock and e820_saved
 729 */
 730u64 __init early_reserve_e820(u64 size, u64 align)
 731{
 732        u64 addr;
 733
 734        addr = __memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
 735        if (addr) {
 736                e820_update_range_saved(addr, size, E820_RAM, E820_RESERVED);
 737                printk(KERN_INFO "e820: update e820_saved for early_reserve_e820\n");
 738                update_e820_saved();
 739        }
 740
 741        return addr;
 742}
 743
 744#ifdef CONFIG_X86_32
 745# ifdef CONFIG_X86_PAE
 746#  define MAX_ARCH_PFN          (1ULL<<(36-PAGE_SHIFT))
 747# else
 748#  define MAX_ARCH_PFN          (1ULL<<(32-PAGE_SHIFT))
 749# endif
 750#else /* CONFIG_X86_32 */
 751# define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
 752#endif
 753
 754/*
 755 * Find the highest page frame number we have available
 756 */
 757static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
 758{
 759        int i;
 760        unsigned long last_pfn = 0;
 761        unsigned long max_arch_pfn = MAX_ARCH_PFN;
 762
 763        for (i = 0; i < e820.nr_map; i++) {
 764                struct e820entry *ei = &e820.map[i];
 765                unsigned long start_pfn;
 766                unsigned long end_pfn;
 767
 768                if (ei->type != type)
 769                        continue;
 770
 771                start_pfn = ei->addr >> PAGE_SHIFT;
 772                end_pfn = (ei->addr + ei->size) >> PAGE_SHIFT;
 773
 774                if (start_pfn >= limit_pfn)
 775                        continue;
 776                if (end_pfn > limit_pfn) {
 777                        last_pfn = limit_pfn;
 778                        break;
 779                }
 780                if (end_pfn > last_pfn)
 781                        last_pfn = end_pfn;
 782        }
 783
 784        if (last_pfn > max_arch_pfn)
 785                last_pfn = max_arch_pfn;
 786
 787        printk(KERN_INFO "e820: last_pfn = %#lx max_arch_pfn = %#lx\n",
 788                         last_pfn, max_arch_pfn);
 789        return last_pfn;
 790}
 791unsigned long __init e820_end_of_ram_pfn(void)
 792{
 793        return e820_end_pfn(MAX_ARCH_PFN, E820_RAM);
 794}
 795
 796unsigned long __init e820_end_of_low_ram_pfn(void)
 797{
 798        return e820_end_pfn(1UL<<(32 - PAGE_SHIFT), E820_RAM);
 799}
 800
 801static void early_panic(char *msg)
 802{
 803        early_printk(msg);
 804        panic(msg);
 805}
 806
 807static int userdef __initdata;
 808
 809/* "mem=nopentium" disables the 4MB page tables. */
 810static int __init parse_memopt(char *p)
 811{
 812        u64 mem_size;
 813
 814        if (!p)
 815                return -EINVAL;
 816
 817        if (!strcmp(p, "nopentium")) {
 818#ifdef CONFIG_X86_32
 819                setup_clear_cpu_cap(X86_FEATURE_PSE);
 820                return 0;
 821#else
 822                printk(KERN_WARNING "mem=nopentium ignored! (only supported on x86_32)\n");
 823                return -EINVAL;
 824#endif
 825        }
 826
 827        userdef = 1;
 828        mem_size = memparse(p, &p);
 829        /* don't remove all of memory when handling "mem={invalid}" param */
 830        if (mem_size == 0)
 831                return -EINVAL;
 832        e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
 833
 834        return 0;
 835}
 836early_param("mem", parse_memopt);
 837
 838static int __init parse_memmap_opt(char *p)
 839{
 840        char *oldp;
 841        u64 start_at, mem_size;
 842
 843        if (!p)
 844                return -EINVAL;
 845
 846        if (!strncmp(p, "exactmap", 8)) {
 847#ifdef CONFIG_CRASH_DUMP
 848                /*
 849                 * If we are doing a crash dump, we still need to know
 850                 * the real mem size before original memory map is
 851                 * reset.
 852                 */
 853                saved_max_pfn = e820_end_of_ram_pfn();
 854#endif
 855                e820.nr_map = 0;
 856                userdef = 1;
 857                return 0;
 858        }
 859
 860        oldp = p;
 861        mem_size = memparse(p, &p);
 862        if (p == oldp)
 863                return -EINVAL;
 864
 865        userdef = 1;
 866        if (*p == '@') {
 867                start_at = memparse(p+1, &p);
 868                e820_add_region(start_at, mem_size, E820_RAM);
 869        } else if (*p == '#') {
 870                start_at = memparse(p+1, &p);
 871                e820_add_region(start_at, mem_size, E820_ACPI);
 872        } else if (*p == '$') {
 873                start_at = memparse(p+1, &p);
 874                e820_add_region(start_at, mem_size, E820_RESERVED);
 875        } else
 876                e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
 877
 878        return *p == '\0' ? 0 : -EINVAL;
 879}
 880early_param("memmap", parse_memmap_opt);
 881
 882void __init finish_e820_parsing(void)
 883{
 884        if (userdef) {
 885                u32 nr = e820.nr_map;
 886
 887                if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0)
 888                        early_panic("Invalid user supplied memory map");
 889                e820.nr_map = nr;
 890
 891                printk(KERN_INFO "e820: user-defined physical RAM map:\n");
 892                e820_print_map("user");
 893        }
 894}
 895
 896static inline const char *e820_type_to_string(int e820_type)
 897{
 898        switch (e820_type) {
 899        case E820_RESERVED_KERN:
 900        case E820_RAM:  return "System RAM";
 901        case E820_ACPI: return "ACPI Tables";
 902        case E820_NVS:  return "ACPI Non-volatile Storage";
 903        case E820_UNUSABLE:     return "Unusable memory";
 904        default:        return "reserved";
 905        }
 906}
 907
 908/*
 909 * Mark e820 reserved areas as busy for the resource manager.
 910 */
 911static struct resource __initdata *e820_res;
 912void __init e820_reserve_resources(void)
 913{
 914        int i;
 915        struct resource *res;
 916        u64 end;
 917
 918        res = alloc_bootmem(sizeof(struct resource) * e820.nr_map);
 919        e820_res = res;
 920        for (i = 0; i < e820.nr_map; i++) {
 921                end = e820.map[i].addr + e820.map[i].size - 1;
 922                if (end != (resource_size_t)end) {
 923                        res++;
 924                        continue;
 925                }
 926                res->name = e820_type_to_string(e820.map[i].type);
 927                res->start = e820.map[i].addr;
 928                res->end = end;
 929
 930                res->flags = IORESOURCE_MEM;
 931
 932                /*
 933                 * don't register the region that could be conflicted with
 934                 * pci device BAR resource and insert them later in
 935                 * pcibios_resource_survey()
 936                 */
 937                if (e820.map[i].type != E820_RESERVED || res->start < (1ULL<<20)) {
 938                        res->flags |= IORESOURCE_BUSY;
 939                        insert_resource(&iomem_resource, res);
 940                }
 941                res++;
 942        }
 943
 944        for (i = 0; i < e820_saved.nr_map; i++) {
 945                struct e820entry *entry = &e820_saved.map[i];
 946                firmware_map_add_early(entry->addr,
 947                        entry->addr + entry->size,
 948                        e820_type_to_string(entry->type));
 949        }
 950}
 951
 952/* How much should we pad RAM ending depending on where it is? */
 953static unsigned long ram_alignment(resource_size_t pos)
 954{
 955        unsigned long mb = pos >> 20;
 956
 957        /* To 64kB in the first megabyte */
 958        if (!mb)
 959                return 64*1024;
 960
 961        /* To 1MB in the first 16MB */
 962        if (mb < 16)
 963                return 1024*1024;
 964
 965        /* To 64MB for anything above that */
 966        return 64*1024*1024;
 967}
 968
 969#define MAX_RESOURCE_SIZE ((resource_size_t)-1)
 970
 971void __init e820_reserve_resources_late(void)
 972{
 973        int i;
 974        struct resource *res;
 975
 976        res = e820_res;
 977        for (i = 0; i < e820.nr_map; i++) {
 978                if (!res->parent && res->end)
 979                        insert_resource_expand_to_fit(&iomem_resource, res);
 980                res++;
 981        }
 982
 983        /*
 984         * Try to bump up RAM regions to reasonable boundaries to
 985         * avoid stolen RAM:
 986         */
 987        for (i = 0; i < e820.nr_map; i++) {
 988                struct e820entry *entry = &e820.map[i];
 989                u64 start, end;
 990
 991                if (entry->type != E820_RAM)
 992                        continue;
 993                start = entry->addr + entry->size;
 994                end = round_up(start, ram_alignment(start)) - 1;
 995                if (end > MAX_RESOURCE_SIZE)
 996                        end = MAX_RESOURCE_SIZE;
 997                if (start >= end)
 998                        continue;
 999                printk(KERN_DEBUG
1000                       "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n",
1001                       start, end);
1002                reserve_region_with_split(&iomem_resource, start, end,
1003                                          "RAM buffer");
1004        }
1005}
1006
1007char *__init default_machine_specific_memory_setup(void)
1008{
1009        char *who = "BIOS-e820";
1010        u32 new_nr;
1011        /*
1012         * Try to copy the BIOS-supplied E820-map.
1013         *
1014         * Otherwise fake a memory map; one section from 0k->640k,
1015         * the next section from 1mb->appropriate_mem_k
1016         */
1017        new_nr = boot_params.e820_entries;
1018        sanitize_e820_map(boot_params.e820_map,
1019                        ARRAY_SIZE(boot_params.e820_map),
1020                        &new_nr);
1021        boot_params.e820_entries = new_nr;
1022        if (append_e820_map(boot_params.e820_map, boot_params.e820_entries)
1023          < 0) {
1024                u64 mem_size;
1025
1026                /* compare results from other methods and take the greater */
1027                if (boot_params.alt_mem_k
1028                    < boot_params.screen_info.ext_mem_k) {
1029                        mem_size = boot_params.screen_info.ext_mem_k;
1030                        who = "BIOS-88";
1031                } else {
1032                        mem_size = boot_params.alt_mem_k;
1033                        who = "BIOS-e801";
1034                }
1035
1036                e820.nr_map = 0;
1037                e820_add_region(0, LOWMEMSIZE(), E820_RAM);
1038                e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
1039        }
1040
1041        /* In case someone cares... */
1042        return who;
1043}
1044
1045void __init setup_memory_map(void)
1046{
1047        char *who;
1048
1049        who = x86_init.resources.memory_setup();
1050        memcpy(&e820_saved, &e820, sizeof(struct e820map));
1051        printk(KERN_INFO "e820: BIOS-provided physical RAM map:\n");
1052        e820_print_map(who);
1053}
1054
1055void __init memblock_x86_fill(void)
1056{
1057        int i;
1058        u64 end;
1059
1060        /*
1061         * EFI may have more than 128 entries
1062         * We are safe to enable resizing, beause memblock_x86_fill()
1063         * is rather later for x86
1064         */
1065        memblock_allow_resize();
1066
1067        for (i = 0; i < e820.nr_map; i++) {
1068                struct e820entry *ei = &e820.map[i];
1069
1070                end = ei->addr + ei->size;
1071                if (end != (resource_size_t)end)
1072                        continue;
1073
1074                if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
1075                        continue;
1076
1077                memblock_add(ei->addr, ei->size);
1078        }
1079
1080        memblock_dump_all();
1081}
1082
1083void __init memblock_find_dma_reserve(void)
1084{
1085#ifdef CONFIG_X86_64
1086        u64 nr_pages = 0, nr_free_pages = 0;
1087        unsigned long start_pfn, end_pfn;
1088        phys_addr_t start, end;
1089        int i;
1090        u64 u;
1091
1092        /*
1093         * need to find out used area below MAX_DMA_PFN
1094         * need to use memblock to get free size in [0, MAX_DMA_PFN]
1095         * at first, and assume boot_mem will not take below MAX_DMA_PFN
1096         */
1097        for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
1098                start_pfn = min_t(unsigned long, start_pfn, MAX_DMA_PFN);
1099                end_pfn = min_t(unsigned long, end_pfn, MAX_DMA_PFN);
1100                nr_pages += end_pfn - start_pfn;
1101        }
1102
1103        for_each_free_mem_range(u, MAX_NUMNODES, &start, &end, NULL) {
1104                start_pfn = min_t(unsigned long, PFN_UP(start), MAX_DMA_PFN);
1105                end_pfn = min_t(unsigned long, PFN_DOWN(end), MAX_DMA_PFN);
1106                if (start_pfn < end_pfn)
1107                        nr_free_pages += end_pfn - start_pfn;
1108        }
1109
1110        set_dma_reserve(nr_pages - nr_free_pages);
1111#endif
1112}
1113
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