arch/x86/kernel/e820.c

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This source file includes following definitions.
_e820__mapped_any
e820__mapped_raw_any
e820__mapped_any
__e820__mapped_all
e820__mapped_all
e820__get_entry_type
__e820__range_add
e820__range_add
e820_print_type
e820__print_table
cpcompare
e820__update_table
__append_e820_table
append_e820_table
__e820__range_update
e820__range_update
e820__range_update_kexec
e820__range_remove
e820__update_table_print
e820__update_table_kexec
e820_search_gap
e820__setup_pci_gap
e820__reallocate_tables
e820__memory_setup_extended
e820__register_nosave_regions
e820__register_nvs_regions
e820__memblock_alloc_reserved
e820_end_pfn
e820__end_of_ram_pfn
e820__end_of_low_ram_pfn
early_panic
parse_memopt
parse_memmap_one
parse_memmap_opt
e820__reserve_setup_data
e820__finish_early_params
e820_type_to_string
e820_type_to_iomem_type
e820_type_to_iores_desc
do_mark_busy
e820__reserve_resources
ram_alignment
e820__reserve_resources_late
e820__memory_setup_default
e820__memory_setup
e820__memblock_setup
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Low level x86 E820 memory map handling functions.
   4  *
   5  * The firmware and bootloader passes us the "E820 table", which is the primary
   6  * physical memory layout description available about x86 systems.
   7  *
   8  * The kernel takes the E820 memory layout and optionally modifies it with
   9  * quirks and other tweaks, and feeds that into the generic Linux memory
  10  * allocation code routines via a platform independent interface (memblock, etc.).
  11  */
  12 #include <linux/crash_dump.h>
  13 #include <linux/memblock.h>
  14 #include <linux/suspend.h>
  15 #include <linux/acpi.h>
  16 #include <linux/firmware-map.h>
  17 #include <linux/sort.h>
  18 #include <linux/memory_hotplug.h>
  19 
  20 #include <asm/e820/api.h>
  21 #include <asm/setup.h>
  22 
  23 /*
  24  * We organize the E820 table into three main data structures:
  25  *
  26  * - 'e820_table_firmware': the original firmware version passed to us by the
  27  *   bootloader - not modified by the kernel. It is composed of two parts:
  28  *   the first 128 E820 memory entries in boot_params.e820_table and the remaining
  29  *   (if any) entries of the SETUP_E820_EXT nodes. We use this to:
  30  *
  31  *       - inform the user about the firmware's notion of memory layout
  32  *         via /sys/firmware/memmap
  33  *
  34  *       - the hibernation code uses it to generate a kernel-independent MD5
  35  *         fingerprint of the physical memory layout of a system.
  36  *
  37  * - 'e820_table_kexec': a slightly modified (by the kernel) firmware version
  38  *   passed to us by the bootloader - the major difference between
  39  *   e820_table_firmware[] and this one is that, the latter marks the setup_data
  40  *   list created by the EFI boot stub as reserved, so that kexec can reuse the
  41  *   setup_data information in the second kernel. Besides, e820_table_kexec[]
  42  *   might also be modified by the kexec itself to fake a mptable.
  43  *   We use this to:
  44  *
  45  *       - kexec, which is a bootloader in disguise, uses the original E820
  46  *         layout to pass to the kexec-ed kernel. This way the original kernel
  47  *         can have a restricted E820 map while the kexec()-ed kexec-kernel
  48  *         can have access to full memory - etc.
  49  *
  50  * - 'e820_table': this is the main E820 table that is massaged by the
  51  *   low level x86 platform code, or modified by boot parameters, before
  52  *   passed on to higher level MM layers.
  53  *
  54  * Once the E820 map has been converted to the standard Linux memory layout
  55  * information its role stops - modifying it has no effect and does not get
  56  * re-propagated. So itsmain role is a temporary bootstrap storage of firmware
  57  * specific memory layout data during early bootup.
  58  */
  59 static struct e820_table e820_table_init                __initdata;
  60 static struct e820_table e820_table_kexec_init          __initdata;
  61 static struct e820_table e820_table_firmware_init       __initdata;
  62 
  63 struct e820_table *e820_table __refdata                 = &e820_table_init;
  64 struct e820_table *e820_table_kexec __refdata           = &e820_table_kexec_init;
  65 struct e820_table *e820_table_firmware __refdata        = &e820_table_firmware_init;
  66 
  67 /* For PCI or other memory-mapped resources */
  68 unsigned long pci_mem_start = 0xaeedbabe;
  69 #ifdef CONFIG_PCI
  70 EXPORT_SYMBOL(pci_mem_start);
  71 #endif
  72 
  73 /*
  74  * This function checks if any part of the range <start,end> is mapped
  75  * with type.
  76  */
  77 static bool _e820__mapped_any(struct e820_table *table,
  78                               u64 start, u64 end, enum e820_type type)
  79 {
  80         int i;
  81 
  82         for (i = 0; i < table->nr_entries; i++) {
  83                 struct e820_entry *entry = &table->entries[i];
  84 
  85                 if (type && entry->type != type)
  86                         continue;
  87                 if (entry->addr >= end || entry->addr + entry->size <= start)
  88                         continue;
  89                 return true;
  90         }
  91         return false;
  92 }
  93 
  94 bool e820__mapped_raw_any(u64 start, u64 end, enum e820_type type)
  95 {
  96         return _e820__mapped_any(e820_table_firmware, start, end, type);
  97 }
  98 EXPORT_SYMBOL_GPL(e820__mapped_raw_any);
  99 
 100 bool e820__mapped_any(u64 start, u64 end, enum e820_type type)
 101 {
 102         return _e820__mapped_any(e820_table, start, end, type);
 103 }
 104 EXPORT_SYMBOL_GPL(e820__mapped_any);
 105 
 106 /*
 107  * This function checks if the entire <start,end> range is mapped with 'type'.
 108  *
 109  * Note: this function only works correctly once the E820 table is sorted and
 110  * not-overlapping (at least for the range specified), which is the case normally.
 111  */
 112 static struct e820_entry *__e820__mapped_all(u64 start, u64 end,
 113                                              enum e820_type type)
 114 {
 115         int i;
 116 
 117         for (i = 0; i < e820_table->nr_entries; i++) {
 118                 struct e820_entry *entry = &e820_table->entries[i];
 119 
 120                 if (type && entry->type != type)
 121                         continue;
 122 
 123                 /* Is the region (part) in overlap with the current region? */
 124                 if (entry->addr >= end || entry->addr + entry->size <= start)
 125                         continue;
 126 
 127                 /*
 128                  * If the region is at the beginning of <start,end> we move
 129                  * 'start' to the end of the region since it's ok until there
 130                  */
 131                 if (entry->addr <= start)
 132                         start = entry->addr + entry->size;
 133 
 134                 /*
 135                  * If 'start' is now at or beyond 'end', we're done, full
 136                  * coverage of the desired range exists:
 137                  */
 138                 if (start >= end)
 139                         return entry;
 140         }
 141 
 142         return NULL;
 143 }
 144 
 145 /*
 146  * This function checks if the entire range <start,end> is mapped with type.
 147  */
 148 bool __init e820__mapped_all(u64 start, u64 end, enum e820_type type)
 149 {
 150         return __e820__mapped_all(start, end, type);
 151 }
 152 
 153 /*
 154  * This function returns the type associated with the range <start,end>.
 155  */
 156 int e820__get_entry_type(u64 start, u64 end)
 157 {
 158         struct e820_entry *entry = __e820__mapped_all(start, end, 0);
 159 
 160         return entry ? entry->type : -EINVAL;
 161 }
 162 
 163 /*
 164  * Add a memory region to the kernel E820 map.
 165  */
 166 static void __init __e820__range_add(struct e820_table *table, u64 start, u64 size, enum e820_type type)
 167 {
 168         int x = table->nr_entries;
 169 
 170         if (x >= ARRAY_SIZE(table->entries)) {
 171                 pr_err("too many entries; ignoring [mem %#010llx-%#010llx]\n",
 172                        start, start + size - 1);
 173                 return;
 174         }
 175 
 176         table->entries[x].addr = start;
 177         table->entries[x].size = size;
 178         table->entries[x].type = type;
 179         table->nr_entries++;
 180 }
 181 
 182 void __init e820__range_add(u64 start, u64 size, enum e820_type type)
 183 {
 184         __e820__range_add(e820_table, start, size, type);
 185 }
 186 
 187 static void __init e820_print_type(enum e820_type type)
 188 {
 189         switch (type) {
 190         case E820_TYPE_RAM:             /* Fall through: */
 191         case E820_TYPE_RESERVED_KERN:   pr_cont("usable");                      break;
 192         case E820_TYPE_RESERVED:        pr_cont("reserved");                    break;
 193         case E820_TYPE_ACPI:            pr_cont("ACPI data");                   break;
 194         case E820_TYPE_NVS:             pr_cont("ACPI NVS");                    break;
 195         case E820_TYPE_UNUSABLE:        pr_cont("unusable");                    break;
 196         case E820_TYPE_PMEM:            /* Fall through: */
 197         case E820_TYPE_PRAM:            pr_cont("persistent (type %u)", type);  break;
 198         default:                        pr_cont("type %u", type);               break;
 199         }
 200 }
 201 
 202 void __init e820__print_table(char *who)
 203 {
 204         int i;
 205 
 206         for (i = 0; i < e820_table->nr_entries; i++) {
 207                 pr_info("%s: [mem %#018Lx-%#018Lx] ",
 208                         who,
 209                         e820_table->entries[i].addr,
 210                         e820_table->entries[i].addr + e820_table->entries[i].size - 1);
 211 
 212                 e820_print_type(e820_table->entries[i].type);
 213                 pr_cont("\n");
 214         }
 215 }
 216 
 217 /*
 218  * Sanitize an E820 map.
 219  *
 220  * Some E820 layouts include overlapping entries. The following
 221  * replaces the original E820 map with a new one, removing overlaps,
 222  * and resolving conflicting memory types in favor of highest
 223  * numbered type.
 224  *
 225  * The input parameter 'entries' points to an array of 'struct
 226  * e820_entry' which on entry has elements in the range [0, *nr_entries)
 227  * valid, and which has space for up to max_nr_entries entries.
 228  * On return, the resulting sanitized E820 map entries will be in
 229  * overwritten in the same location, starting at 'entries'.
 230  *
 231  * The integer pointed to by nr_entries must be valid on entry (the
 232  * current number of valid entries located at 'entries'). If the
 233  * sanitizing succeeds the *nr_entries will be updated with the new
 234  * number of valid entries (something no more than max_nr_entries).
 235  *
 236  * The return value from e820__update_table() is zero if it
 237  * successfully 'sanitized' the map entries passed in, and is -1
 238  * if it did nothing, which can happen if either of (1) it was
 239  * only passed one map entry, or (2) any of the input map entries
 240  * were invalid (start + size < start, meaning that the size was
 241  * so big the described memory range wrapped around through zero.)
 242  *
 243  *      Visually we're performing the following
 244  *      (1,2,3,4 = memory types)...
 245  *
 246  *      Sample memory map (w/overlaps):
 247  *         ____22__________________
 248  *         ______________________4_
 249  *         ____1111________________
 250  *         _44_____________________
 251  *         11111111________________
 252  *         ____________________33__
 253  *         ___________44___________
 254  *         __________33333_________
 255  *         ______________22________
 256  *         ___________________2222_
 257  *         _________111111111______
 258  *         _____________________11_
 259  *         _________________4______
 260  *
 261  *      Sanitized equivalent (no overlap):
 262  *         1_______________________
 263  *         _44_____________________
 264  *         ___1____________________
 265  *         ____22__________________
 266  *         ______11________________
 267  *         _________1______________
 268  *         __________3_____________
 269  *         ___________44___________
 270  *         _____________33_________
 271  *         _______________2________
 272  *         ________________1_______
 273  *         _________________4______
 274  *         ___________________2____
 275  *         ____________________33__
 276  *         ______________________4_
 277  */
 278 struct change_member {
 279         /* Pointer to the original entry: */
 280         struct e820_entry       *entry;
 281         /* Address for this change point: */
 282         unsigned long long      addr;
 283 };
 284 
 285 static struct change_member     change_point_list[2*E820_MAX_ENTRIES]   __initdata;
 286 static struct change_member     *change_point[2*E820_MAX_ENTRIES]       __initdata;
 287 static struct e820_entry        *overlap_list[E820_MAX_ENTRIES]         __initdata;
 288 static struct e820_entry        new_entries[E820_MAX_ENTRIES]           __initdata;
 289 
 290 static int __init cpcompare(const void *a, const void *b)
 291 {
 292         struct change_member * const *app = a, * const *bpp = b;
 293         const struct change_member *ap = *app, *bp = *bpp;
 294 
 295         /*
 296          * Inputs are pointers to two elements of change_point[].  If their
 297          * addresses are not equal, their difference dominates.  If the addresses
 298          * are equal, then consider one that represents the end of its region
 299          * to be greater than one that does not.
 300          */
 301         if (ap->addr != bp->addr)
 302                 return ap->addr > bp->addr ? 1 : -1;
 303 
 304         return (ap->addr != ap->entry->addr) - (bp->addr != bp->entry->addr);
 305 }
 306 
 307 int __init e820__update_table(struct e820_table *table)
 308 {
 309         struct e820_entry *entries = table->entries;
 310         u32 max_nr_entries = ARRAY_SIZE(table->entries);
 311         enum e820_type current_type, last_type;
 312         unsigned long long last_addr;
 313         u32 new_nr_entries, overlap_entries;
 314         u32 i, chg_idx, chg_nr;
 315 
 316         /* If there's only one memory region, don't bother: */
 317         if (table->nr_entries < 2)
 318                 return -1;
 319 
 320         BUG_ON(table->nr_entries > max_nr_entries);
 321 
 322         /* Bail out if we find any unreasonable addresses in the map: */
 323         for (i = 0; i < table->nr_entries; i++) {
 324                 if (entries[i].addr + entries[i].size < entries[i].addr)
 325                         return -1;
 326         }
 327 
 328         /* Create pointers for initial change-point information (for sorting): */
 329         for (i = 0; i < 2 * table->nr_entries; i++)
 330                 change_point[i] = &change_point_list[i];
 331 
 332         /*
 333          * Record all known change-points (starting and ending addresses),
 334          * omitting empty memory regions:
 335          */
 336         chg_idx = 0;
 337         for (i = 0; i < table->nr_entries; i++) {
 338                 if (entries[i].size != 0) {
 339                         change_point[chg_idx]->addr     = entries[i].addr;
 340                         change_point[chg_idx++]->entry  = &entries[i];
 341                         change_point[chg_idx]->addr     = entries[i].addr + entries[i].size;
 342                         change_point[chg_idx++]->entry  = &entries[i];
 343                 }
 344         }
 345         chg_nr = chg_idx;
 346 
 347         /* Sort change-point list by memory addresses (low -> high): */
 348         sort(change_point, chg_nr, sizeof(*change_point), cpcompare, NULL);
 349 
 350         /* Create a new memory map, removing overlaps: */
 351         overlap_entries = 0;     /* Number of entries in the overlap table */
 352         new_nr_entries = 0;      /* Index for creating new map entries */
 353         last_type = 0;           /* Start with undefined memory type */
 354         last_addr = 0;           /* Start with 0 as last starting address */
 355 
 356         /* Loop through change-points, determining effect on the new map: */
 357         for (chg_idx = 0; chg_idx < chg_nr; chg_idx++) {
 358                 /* Keep track of all overlapping entries */
 359                 if (change_point[chg_idx]->addr == change_point[chg_idx]->entry->addr) {
 360                         /* Add map entry to overlap list (> 1 entry implies an overlap) */
 361                         overlap_list[overlap_entries++] = change_point[chg_idx]->entry;
 362                 } else {
 363                         /* Remove entry from list (order independent, so swap with last): */
 364                         for (i = 0; i < overlap_entries; i++) {
 365                                 if (overlap_list[i] == change_point[chg_idx]->entry)
 366                                         overlap_list[i] = overlap_list[overlap_entries-1];
 367                         }
 368                         overlap_entries--;
 369                 }
 370                 /*
 371                  * If there are overlapping entries, decide which
 372                  * "type" to use (larger value takes precedence --
 373                  * 1=usable, 2,3,4,4+=unusable)
 374                  */
 375                 current_type = 0;
 376                 for (i = 0; i < overlap_entries; i++) {
 377                         if (overlap_list[i]->type > current_type)
 378                                 current_type = overlap_list[i]->type;
 379                 }
 380 
 381                 /* Continue building up new map based on this information: */
 382                 if (current_type != last_type || current_type == E820_TYPE_PRAM) {
 383                         if (last_type != 0)      {
 384                                 new_entries[new_nr_entries].size = change_point[chg_idx]->addr - last_addr;
 385                                 /* Move forward only if the new size was non-zero: */
 386                                 if (new_entries[new_nr_entries].size != 0)
 387                                         /* No more space left for new entries? */
 388                                         if (++new_nr_entries >= max_nr_entries)
 389                                                 break;
 390                         }
 391                         if (current_type != 0)  {
 392                                 new_entries[new_nr_entries].addr = change_point[chg_idx]->addr;
 393                                 new_entries[new_nr_entries].type = current_type;
 394                                 last_addr = change_point[chg_idx]->addr;
 395                         }
 396                         last_type = current_type;
 397                 }
 398         }
 399 
 400         /* Copy the new entries into the original location: */
 401         memcpy(entries, new_entries, new_nr_entries*sizeof(*entries));
 402         table->nr_entries = new_nr_entries;
 403 
 404         return 0;
 405 }
 406 
 407 static int __init __append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
 408 {
 409         struct boot_e820_entry *entry = entries;
 410 
 411         while (nr_entries) {
 412                 u64 start = entry->addr;
 413                 u64 size = entry->size;
 414                 u64 end = start + size - 1;
 415                 u32 type = entry->type;
 416 
 417                 /* Ignore the entry on 64-bit overflow: */
 418                 if (start > end && likely(size))
 419                         return -1;
 420 
 421                 e820__range_add(start, size, type);
 422 
 423                 entry++;
 424                 nr_entries--;
 425         }
 426         return 0;
 427 }
 428 
 429 /*
 430  * Copy the BIOS E820 map into a safe place.
 431  *
 432  * Sanity-check it while we're at it..
 433  *
 434  * If we're lucky and live on a modern system, the setup code
 435  * will have given us a memory map that we can use to properly
 436  * set up memory.  If we aren't, we'll fake a memory map.
 437  */
 438 static int __init append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
 439 {
 440         /* Only one memory region (or negative)? Ignore it */
 441         if (nr_entries < 2)
 442                 return -1;
 443 
 444         return __append_e820_table(entries, nr_entries);
 445 }
 446 
 447 static u64 __init
 448 __e820__range_update(struct e820_table *table, u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
 449 {
 450         u64 end;
 451         unsigned int i;
 452         u64 real_updated_size = 0;
 453 
 454         BUG_ON(old_type == new_type);
 455 
 456         if (size > (ULLONG_MAX - start))
 457                 size = ULLONG_MAX - start;
 458 
 459         end = start + size;
 460         printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ", start, end - 1);
 461         e820_print_type(old_type);
 462         pr_cont(" ==> ");
 463         e820_print_type(new_type);
 464         pr_cont("\n");
 465 
 466         for (i = 0; i < table->nr_entries; i++) {
 467                 struct e820_entry *entry = &table->entries[i];
 468                 u64 final_start, final_end;
 469                 u64 entry_end;
 470 
 471                 if (entry->type != old_type)
 472                         continue;
 473 
 474                 entry_end = entry->addr + entry->size;
 475 
 476                 /* Completely covered by new range? */
 477                 if (entry->addr >= start && entry_end <= end) {
 478                         entry->type = new_type;
 479                         real_updated_size += entry->size;
 480                         continue;
 481                 }
 482 
 483                 /* New range is completely covered? */
 484                 if (entry->addr < start && entry_end > end) {
 485                         __e820__range_add(table, start, size, new_type);
 486                         __e820__range_add(table, end, entry_end - end, entry->type);
 487                         entry->size = start - entry->addr;
 488                         real_updated_size += size;
 489                         continue;
 490                 }
 491 
 492                 /* Partially covered: */
 493                 final_start = max(start, entry->addr);
 494                 final_end = min(end, entry_end);
 495                 if (final_start >= final_end)
 496                         continue;
 497 
 498                 __e820__range_add(table, final_start, final_end - final_start, new_type);
 499 
 500                 real_updated_size += final_end - final_start;
 501 
 502                 /*
 503                  * Left range could be head or tail, so need to update
 504                  * its size first:
 505                  */
 506                 entry->size -= final_end - final_start;
 507                 if (entry->addr < final_start)
 508                         continue;
 509 
 510                 entry->addr = final_end;
 511         }
 512         return real_updated_size;
 513 }
 514 
 515 u64 __init e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
 516 {
 517         return __e820__range_update(e820_table, start, size, old_type, new_type);
 518 }
 519 
 520 static u64 __init e820__range_update_kexec(u64 start, u64 size, enum e820_type old_type, enum e820_type  new_type)
 521 {
 522         return __e820__range_update(e820_table_kexec, start, size, old_type, new_type);
 523 }
 524 
 525 /* Remove a range of memory from the E820 table: */
 526 u64 __init e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type)
 527 {
 528         int i;
 529         u64 end;
 530         u64 real_removed_size = 0;
 531 
 532         if (size > (ULLONG_MAX - start))
 533                 size = ULLONG_MAX - start;
 534 
 535         end = start + size;
 536         printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1);
 537         if (check_type)
 538                 e820_print_type(old_type);
 539         pr_cont("\n");
 540 
 541         for (i = 0; i < e820_table->nr_entries; i++) {
 542                 struct e820_entry *entry = &e820_table->entries[i];
 543                 u64 final_start, final_end;
 544                 u64 entry_end;
 545 
 546                 if (check_type && entry->type != old_type)
 547                         continue;
 548 
 549                 entry_end = entry->addr + entry->size;
 550 
 551                 /* Completely covered? */
 552                 if (entry->addr >= start && entry_end <= end) {
 553                         real_removed_size += entry->size;
 554                         memset(entry, 0, sizeof(*entry));
 555                         continue;
 556                 }
 557 
 558                 /* Is the new range completely covered? */
 559                 if (entry->addr < start && entry_end > end) {
 560                         e820__range_add(end, entry_end - end, entry->type);
 561                         entry->size = start - entry->addr;
 562                         real_removed_size += size;
 563                         continue;
 564                 }
 565 
 566                 /* Partially covered: */
 567                 final_start = max(start, entry->addr);
 568                 final_end = min(end, entry_end);
 569                 if (final_start >= final_end)
 570                         continue;
 571 
 572                 real_removed_size += final_end - final_start;
 573 
 574                 /*
 575                  * Left range could be head or tail, so need to update
 576                  * the size first:
 577                  */
 578                 entry->size -= final_end - final_start;
 579                 if (entry->addr < final_start)
 580                         continue;
 581 
 582                 entry->addr = final_end;
 583         }
 584         return real_removed_size;
 585 }
 586 
 587 void __init e820__update_table_print(void)
 588 {
 589         if (e820__update_table(e820_table))
 590                 return;
 591 
 592         pr_info("modified physical RAM map:\n");
 593         e820__print_table("modified");
 594 }
 595 
 596 static void __init e820__update_table_kexec(void)
 597 {
 598         e820__update_table(e820_table_kexec);
 599 }
 600 
 601 #define MAX_GAP_END 0x100000000ull
 602 
 603 /*
 604  * Search for a gap in the E820 memory space from 0 to MAX_GAP_END (4GB).
 605  */
 606 static int __init e820_search_gap(unsigned long *gapstart, unsigned long *gapsize)
 607 {
 608         unsigned long long last = MAX_GAP_END;
 609         int i = e820_table->nr_entries;
 610         int found = 0;
 611 
 612         while (--i >= 0) {
 613                 unsigned long long start = e820_table->entries[i].addr;
 614                 unsigned long long end = start + e820_table->entries[i].size;
 615 
 616                 /*
 617                  * Since "last" is at most 4GB, we know we'll
 618                  * fit in 32 bits if this condition is true:
 619                  */
 620                 if (last > end) {
 621                         unsigned long gap = last - end;
 622 
 623                         if (gap >= *gapsize) {
 624                                 *gapsize = gap;
 625                                 *gapstart = end;
 626                                 found = 1;
 627                         }
 628                 }
 629                 if (start < last)
 630                         last = start;
 631         }
 632         return found;
 633 }
 634 
 635 /*
 636  * Search for the biggest gap in the low 32 bits of the E820
 637  * memory space. We pass this space to the PCI subsystem, so
 638  * that it can assign MMIO resources for hotplug or
 639  * unconfigured devices in.
 640  *
 641  * Hopefully the BIOS let enough space left.
 642  */
 643 __init void e820__setup_pci_gap(void)
 644 {
 645         unsigned long gapstart, gapsize;
 646         int found;
 647 
 648         gapsize = 0x400000;
 649         found  = e820_search_gap(&gapstart, &gapsize);
 650 
 651         if (!found) {
 652 #ifdef CONFIG_X86_64
 653                 gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
 654                 pr_err("Cannot find an available gap in the 32-bit address range\n");
 655                 pr_err("PCI devices with unassigned 32-bit BARs may not work!\n");
 656 #else
 657                 gapstart = 0x10000000;
 658 #endif
 659         }
 660 
 661         /*
 662          * e820__reserve_resources_late() protects stolen RAM already:
 663          */
 664         pci_mem_start = gapstart;
 665 
 666         pr_info("[mem %#010lx-%#010lx] available for PCI devices\n",
 667                 gapstart, gapstart + gapsize - 1);
 668 }
 669 
 670 /*
 671  * Called late during init, in free_initmem().
 672  *
 673  * Initial e820_table and e820_table_kexec are largish __initdata arrays.
 674  *
 675  * Copy them to a (usually much smaller) dynamically allocated area that is
 676  * sized precisely after the number of e820 entries.
 677  *
 678  * This is done after we've performed all the fixes and tweaks to the tables.
 679  * All functions which modify them are __init functions, which won't exist
 680  * after free_initmem().
 681  */
 682 __init void e820__reallocate_tables(void)
 683 {
 684         struct e820_table *n;
 685         int size;
 686 
 687         size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table->nr_entries;
 688         n = kmemdup(e820_table, size, GFP_KERNEL);
 689         BUG_ON(!n);
 690         e820_table = n;
 691 
 692         size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_kexec->nr_entries;
 693         n = kmemdup(e820_table_kexec, size, GFP_KERNEL);
 694         BUG_ON(!n);
 695         e820_table_kexec = n;
 696 
 697         size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries;
 698         n = kmemdup(e820_table_firmware, size, GFP_KERNEL);
 699         BUG_ON(!n);
 700         e820_table_firmware = n;
 701 }
 702 
 703 /*
 704  * Because of the small fixed size of struct boot_params, only the first
 705  * 128 E820 memory entries are passed to the kernel via boot_params.e820_table,
 706  * the remaining (if any) entries are passed via the SETUP_E820_EXT node of
 707  * struct setup_data, which is parsed here.
 708  */
 709 void __init e820__memory_setup_extended(u64 phys_addr, u32 data_len)
 710 {
 711         int entries;
 712         struct boot_e820_entry *extmap;
 713         struct setup_data *sdata;
 714 
 715         sdata = early_memremap(phys_addr, data_len);
 716         entries = sdata->len / sizeof(*extmap);
 717         extmap = (struct boot_e820_entry *)(sdata->data);
 718 
 719         __append_e820_table(extmap, entries);
 720         e820__update_table(e820_table);
 721 
 722         memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec));
 723         memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
 724 
 725         early_memunmap(sdata, data_len);
 726         pr_info("extended physical RAM map:\n");
 727         e820__print_table("extended");
 728 }
 729 
 730 /*
 731  * Find the ranges of physical addresses that do not correspond to
 732  * E820 RAM areas and register the corresponding pages as 'nosave' for
 733  * hibernation (32-bit) or software suspend and suspend to RAM (64-bit).
 734  *
 735  * This function requires the E820 map to be sorted and without any
 736  * overlapping entries.
 737  */
 738 void __init e820__register_nosave_regions(unsigned long limit_pfn)
 739 {
 740         int i;
 741         unsigned long pfn = 0;
 742 
 743         for (i = 0; i < e820_table->nr_entries; i++) {
 744                 struct e820_entry *entry = &e820_table->entries[i];
 745 
 746                 if (pfn < PFN_UP(entry->addr))
 747                         register_nosave_region(pfn, PFN_UP(entry->addr));
 748 
 749                 pfn = PFN_DOWN(entry->addr + entry->size);
 750 
 751                 if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
 752                         register_nosave_region(PFN_UP(entry->addr), pfn);
 753 
 754                 if (pfn >= limit_pfn)
 755                         break;
 756         }
 757 }
 758 
 759 #ifdef CONFIG_ACPI
 760 /*
 761  * Register ACPI NVS memory regions, so that we can save/restore them during
 762  * hibernation and the subsequent resume:
 763  */
 764 static int __init e820__register_nvs_regions(void)
 765 {
 766         int i;
 767 
 768         for (i = 0; i < e820_table->nr_entries; i++) {
 769                 struct e820_entry *entry = &e820_table->entries[i];
 770 
 771                 if (entry->type == E820_TYPE_NVS)
 772                         acpi_nvs_register(entry->addr, entry->size);
 773         }
 774 
 775         return 0;
 776 }
 777 core_initcall(e820__register_nvs_regions);
 778 #endif
 779 
 780 /*
 781  * Allocate the requested number of bytes with the requsted alignment
 782  * and return (the physical address) to the caller. Also register this
 783  * range in the 'kexec' E820 table as a reserved range.
 784  *
 785  * This allows kexec to fake a new mptable, as if it came from the real
 786  * system.
 787  */
 788 u64 __init e820__memblock_alloc_reserved(u64 size, u64 align)
 789 {
 790         u64 addr;
 791 
 792         addr = memblock_phys_alloc(size, align);
 793         if (addr) {
 794                 e820__range_update_kexec(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
 795                 pr_info("update e820_table_kexec for e820__memblock_alloc_reserved()\n");
 796                 e820__update_table_kexec();
 797         }
 798 
 799         return addr;
 800 }
 801 
 802 #ifdef CONFIG_X86_32
 803 # ifdef CONFIG_X86_PAE
 804 #  define MAX_ARCH_PFN          (1ULL<<(36-PAGE_SHIFT))
 805 # else
 806 #  define MAX_ARCH_PFN          (1ULL<<(32-PAGE_SHIFT))
 807 # endif
 808 #else /* CONFIG_X86_32 */
 809 # define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
 810 #endif
 811 
 812 /*
 813  * Find the highest page frame number we have available
 814  */
 815 static unsigned long __init e820_end_pfn(unsigned long limit_pfn, enum e820_type type)
 816 {
 817         int i;
 818         unsigned long last_pfn = 0;
 819         unsigned long max_arch_pfn = MAX_ARCH_PFN;
 820 
 821         for (i = 0; i < e820_table->nr_entries; i++) {
 822                 struct e820_entry *entry = &e820_table->entries[i];
 823                 unsigned long start_pfn;
 824                 unsigned long end_pfn;
 825 
 826                 if (entry->type != type)
 827                         continue;
 828 
 829                 start_pfn = entry->addr >> PAGE_SHIFT;
 830                 end_pfn = (entry->addr + entry->size) >> PAGE_SHIFT;
 831 
 832                 if (start_pfn >= limit_pfn)
 833                         continue;
 834                 if (end_pfn > limit_pfn) {
 835                         last_pfn = limit_pfn;
 836                         break;
 837                 }
 838                 if (end_pfn > last_pfn)
 839                         last_pfn = end_pfn;
 840         }
 841 
 842         if (last_pfn > max_arch_pfn)
 843                 last_pfn = max_arch_pfn;
 844 
 845         pr_info("last_pfn = %#lx max_arch_pfn = %#lx\n",
 846                 last_pfn, max_arch_pfn);
 847         return last_pfn;
 848 }
 849 
 850 unsigned long __init e820__end_of_ram_pfn(void)
 851 {
 852         return e820_end_pfn(MAX_ARCH_PFN, E820_TYPE_RAM);
 853 }
 854 
 855 unsigned long __init e820__end_of_low_ram_pfn(void)
 856 {
 857         return e820_end_pfn(1UL << (32 - PAGE_SHIFT), E820_TYPE_RAM);
 858 }
 859 
 860 static void __init early_panic(char *msg)
 861 {
 862         early_printk(msg);
 863         panic(msg);
 864 }
 865 
 866 static int userdef __initdata;
 867 
 868 /* The "mem=nopentium" boot option disables 4MB page tables on 32-bit kernels: */
 869 static int __init parse_memopt(char *p)
 870 {
 871         u64 mem_size;
 872 
 873         if (!p)
 874                 return -EINVAL;
 875 
 876         if (!strcmp(p, "nopentium")) {
 877 #ifdef CONFIG_X86_32
 878                 setup_clear_cpu_cap(X86_FEATURE_PSE);
 879                 return 0;
 880 #else
 881                 pr_warn("mem=nopentium ignored! (only supported on x86_32)\n");
 882                 return -EINVAL;
 883 #endif
 884         }
 885 
 886         userdef = 1;
 887         mem_size = memparse(p, &p);
 888 
 889         /* Don't remove all memory when getting "mem={invalid}" parameter: */
 890         if (mem_size == 0)
 891                 return -EINVAL;
 892 
 893         e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
 894 
 895 #ifdef CONFIG_MEMORY_HOTPLUG
 896         max_mem_size = mem_size;
 897 #endif
 898 
 899         return 0;
 900 }
 901 early_param("mem", parse_memopt);
 902 
 903 static int __init parse_memmap_one(char *p)
 904 {
 905         char *oldp;
 906         u64 start_at, mem_size;
 907 
 908         if (!p)
 909                 return -EINVAL;
 910 
 911         if (!strncmp(p, "exactmap", 8)) {
 912 #ifdef CONFIG_CRASH_DUMP
 913                 /*
 914                  * If we are doing a crash dump, we still need to know
 915                  * the real memory size before the original memory map is
 916                  * reset.
 917                  */
 918                 saved_max_pfn = e820__end_of_ram_pfn();
 919 #endif
 920                 e820_table->nr_entries = 0;
 921                 userdef = 1;
 922                 return 0;
 923         }
 924 
 925         oldp = p;
 926         mem_size = memparse(p, &p);
 927         if (p == oldp)
 928                 return -EINVAL;
 929 
 930         userdef = 1;
 931         if (*p == '@') {
 932                 start_at = memparse(p+1, &p);
 933                 e820__range_add(start_at, mem_size, E820_TYPE_RAM);
 934         } else if (*p == '#') {
 935                 start_at = memparse(p+1, &p);
 936                 e820__range_add(start_at, mem_size, E820_TYPE_ACPI);
 937         } else if (*p == '$') {
 938                 start_at = memparse(p+1, &p);
 939                 e820__range_add(start_at, mem_size, E820_TYPE_RESERVED);
 940         } else if (*p == '!') {
 941                 start_at = memparse(p+1, &p);
 942                 e820__range_add(start_at, mem_size, E820_TYPE_PRAM);
 943         } else if (*p == '%') {
 944                 enum e820_type from = 0, to = 0;
 945 
 946                 start_at = memparse(p + 1, &p);
 947                 if (*p == '-')
 948                         from = simple_strtoull(p + 1, &p, 0);
 949                 if (*p == '+')
 950                         to = simple_strtoull(p + 1, &p, 0);
 951                 if (*p != '\0')
 952                         return -EINVAL;
 953                 if (from && to)
 954                         e820__range_update(start_at, mem_size, from, to);
 955                 else if (to)
 956                         e820__range_add(start_at, mem_size, to);
 957                 else if (from)
 958                         e820__range_remove(start_at, mem_size, from, 1);
 959                 else
 960                         e820__range_remove(start_at, mem_size, 0, 0);
 961         } else {
 962                 e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
 963         }
 964 
 965         return *p == '\0' ? 0 : -EINVAL;
 966 }
 967 
 968 static int __init parse_memmap_opt(char *str)
 969 {
 970         while (str) {
 971                 char *k = strchr(str, ',');
 972 
 973                 if (k)
 974                         *k++ = 0;
 975 
 976                 parse_memmap_one(str);
 977                 str = k;
 978         }
 979 
 980         return 0;
 981 }
 982 early_param("memmap", parse_memmap_opt);
 983 
 984 /*
 985  * Reserve all entries from the bootloader's extensible data nodes list,
 986  * because if present we are going to use it later on to fetch e820
 987  * entries from it:
 988  */
 989 void __init e820__reserve_setup_data(void)
 990 {
 991         struct setup_data *data;
 992         u64 pa_data;
 993 
 994         pa_data = boot_params.hdr.setup_data;
 995         if (!pa_data)
 996                 return;
 997 
 998         while (pa_data) {
 999                 data = early_memremap(pa_data, sizeof(*data));
1000                 e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
1001                 e820__range_update_kexec(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
1002                 pa_data = data->next;
1003                 early_memunmap(data, sizeof(*data));
1004         }
1005 
1006         e820__update_table(e820_table);
1007         e820__update_table(e820_table_kexec);
1008 
1009         pr_info("extended physical RAM map:\n");
1010         e820__print_table("reserve setup_data");
1011 }
1012 
1013 /*
1014  * Called after parse_early_param(), after early parameters (such as mem=)
1015  * have been processed, in which case we already have an E820 table filled in
1016  * via the parameter callback function(s), but it's not sorted and printed yet:
1017  */
1018 void __init e820__finish_early_params(void)
1019 {
1020         if (userdef) {
1021                 if (e820__update_table(e820_table) < 0)
1022                         early_panic("Invalid user supplied memory map");
1023 
1024                 pr_info("user-defined physical RAM map:\n");
1025                 e820__print_table("user");
1026         }
1027 }
1028 
1029 static const char *__init e820_type_to_string(struct e820_entry *entry)
1030 {
1031         switch (entry->type) {
1032         case E820_TYPE_RESERVED_KERN:   /* Fall-through: */
1033         case E820_TYPE_RAM:             return "System RAM";
1034         case E820_TYPE_ACPI:            return "ACPI Tables";
1035         case E820_TYPE_NVS:             return "ACPI Non-volatile Storage";
1036         case E820_TYPE_UNUSABLE:        return "Unusable memory";
1037         case E820_TYPE_PRAM:            return "Persistent Memory (legacy)";
1038         case E820_TYPE_PMEM:            return "Persistent Memory";
1039         case E820_TYPE_RESERVED:        return "Reserved";
1040         default:                        return "Unknown E820 type";
1041         }
1042 }
1043 
1044 static unsigned long __init e820_type_to_iomem_type(struct e820_entry *entry)
1045 {
1046         switch (entry->type) {
1047         case E820_TYPE_RESERVED_KERN:   /* Fall-through: */
1048         case E820_TYPE_RAM:             return IORESOURCE_SYSTEM_RAM;
1049         case E820_TYPE_ACPI:            /* Fall-through: */
1050         case E820_TYPE_NVS:             /* Fall-through: */
1051         case E820_TYPE_UNUSABLE:        /* Fall-through: */
1052         case E820_TYPE_PRAM:            /* Fall-through: */
1053         case E820_TYPE_PMEM:            /* Fall-through: */
1054         case E820_TYPE_RESERVED:        /* Fall-through: */
1055         default:                        return IORESOURCE_MEM;
1056         }
1057 }
1058 
1059 static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry)
1060 {
1061         switch (entry->type) {
1062         case E820_TYPE_ACPI:            return IORES_DESC_ACPI_TABLES;
1063         case E820_TYPE_NVS:             return IORES_DESC_ACPI_NV_STORAGE;
1064         case E820_TYPE_PMEM:            return IORES_DESC_PERSISTENT_MEMORY;
1065         case E820_TYPE_PRAM:            return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
1066         case E820_TYPE_RESERVED:        return IORES_DESC_RESERVED;
1067         case E820_TYPE_RESERVED_KERN:   /* Fall-through: */
1068         case E820_TYPE_RAM:             /* Fall-through: */
1069         case E820_TYPE_UNUSABLE:        /* Fall-through: */
1070         default:                        return IORES_DESC_NONE;
1071         }
1072 }
1073 
1074 static bool __init do_mark_busy(enum e820_type type, struct resource *res)
1075 {
1076         /* this is the legacy bios/dos rom-shadow + mmio region */
1077         if (res->start < (1ULL<<20))
1078                 return true;
1079 
1080         /*
1081          * Treat persistent memory like device memory, i.e. reserve it
1082          * for exclusive use of a driver
1083          */
1084         switch (type) {
1085         case E820_TYPE_RESERVED:
1086         case E820_TYPE_PRAM:
1087         case E820_TYPE_PMEM:
1088                 return false;
1089         case E820_TYPE_RESERVED_KERN:
1090         case E820_TYPE_RAM:
1091         case E820_TYPE_ACPI:
1092         case E820_TYPE_NVS:
1093         case E820_TYPE_UNUSABLE:
1094         default:
1095                 return true;
1096         }
1097 }
1098 
1099 /*
1100  * Mark E820 reserved areas as busy for the resource manager:
1101  */
1102 
1103 static struct resource __initdata *e820_res;
1104 
1105 void __init e820__reserve_resources(void)
1106 {
1107         int i;
1108         struct resource *res;
1109         u64 end;
1110 
1111         res = memblock_alloc(sizeof(*res) * e820_table->nr_entries,
1112                              SMP_CACHE_BYTES);
1113         if (!res)
1114                 panic("%s: Failed to allocate %zu bytes\n", __func__,
1115                       sizeof(*res) * e820_table->nr_entries);
1116         e820_res = res;
1117 
1118         for (i = 0; i < e820_table->nr_entries; i++) {
1119                 struct e820_entry *entry = e820_table->entries + i;
1120 
1121                 end = entry->addr + entry->size - 1;
1122                 if (end != (resource_size_t)end) {
1123                         res++;
1124                         continue;
1125                 }
1126                 res->start = entry->addr;
1127                 res->end   = end;
1128                 res->name  = e820_type_to_string(entry);
1129                 res->flags = e820_type_to_iomem_type(entry);
1130                 res->desc  = e820_type_to_iores_desc(entry);
1131 
1132                 /*
1133                  * Don't register the region that could be conflicted with
1134                  * PCI device BAR resources and insert them later in
1135                  * pcibios_resource_survey():
1136                  */
1137                 if (do_mark_busy(entry->type, res)) {
1138                         res->flags |= IORESOURCE_BUSY;
1139                         insert_resource(&iomem_resource, res);
1140                 }
1141                 res++;
1142         }
1143 
1144         /* Expose the bootloader-provided memory layout to the sysfs. */
1145         for (i = 0; i < e820_table_firmware->nr_entries; i++) {
1146                 struct e820_entry *entry = e820_table_firmware->entries + i;
1147 
1148                 firmware_map_add_early(entry->addr, entry->addr + entry->size, e820_type_to_string(entry));
1149         }
1150 }
1151 
1152 /*
1153  * How much should we pad the end of RAM, depending on where it is?
1154  */
1155 static unsigned long __init ram_alignment(resource_size_t pos)
1156 {
1157         unsigned long mb = pos >> 20;
1158 
1159         /* To 64kB in the first megabyte */
1160         if (!mb)
1161                 return 64*1024;
1162 
1163         /* To 1MB in the first 16MB */
1164         if (mb < 16)
1165                 return 1024*1024;
1166 
1167         /* To 64MB for anything above that */
1168         return 64*1024*1024;
1169 }
1170 
1171 #define MAX_RESOURCE_SIZE ((resource_size_t)-1)
1172 
1173 void __init e820__reserve_resources_late(void)
1174 {
1175         int i;
1176         struct resource *res;
1177 
1178         res = e820_res;
1179         for (i = 0; i < e820_table->nr_entries; i++) {
1180                 if (!res->parent && res->end)
1181                         insert_resource_expand_to_fit(&iomem_resource, res);
1182                 res++;
1183         }
1184 
1185         /*
1186          * Try to bump up RAM regions to reasonable boundaries, to
1187          * avoid stolen RAM:
1188          */
1189         for (i = 0; i < e820_table->nr_entries; i++) {
1190                 struct e820_entry *entry = &e820_table->entries[i];
1191                 u64 start, end;
1192 
1193                 if (entry->type != E820_TYPE_RAM)
1194                         continue;
1195 
1196                 start = entry->addr + entry->size;
1197                 end = round_up(start, ram_alignment(start)) - 1;
1198                 if (end > MAX_RESOURCE_SIZE)
1199                         end = MAX_RESOURCE_SIZE;
1200                 if (start >= end)
1201                         continue;
1202 
1203                 printk(KERN_DEBUG "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n", start, end);
1204                 reserve_region_with_split(&iomem_resource, start, end, "RAM buffer");
1205         }
1206 }
1207 
1208 /*
1209  * Pass the firmware (bootloader) E820 map to the kernel and process it:
1210  */
1211 char *__init e820__memory_setup_default(void)
1212 {
1213         char *who = "BIOS-e820";
1214 
1215         /*
1216          * Try to copy the BIOS-supplied E820-map.
1217          *
1218          * Otherwise fake a memory map; one section from 0k->640k,
1219          * the next section from 1mb->appropriate_mem_k
1220          */
1221         if (append_e820_table(boot_params.e820_table, boot_params.e820_entries) < 0) {
1222                 u64 mem_size;
1223 
1224                 /* Compare results from other methods and take the one that gives more RAM: */
1225                 if (boot_params.alt_mem_k < boot_params.screen_info.ext_mem_k) {
1226                         mem_size = boot_params.screen_info.ext_mem_k;
1227                         who = "BIOS-88";
1228                 } else {
1229                         mem_size = boot_params.alt_mem_k;
1230                         who = "BIOS-e801";
1231                 }
1232 
1233                 e820_table->nr_entries = 0;
1234                 e820__range_add(0, LOWMEMSIZE(), E820_TYPE_RAM);
1235                 e820__range_add(HIGH_MEMORY, mem_size << 10, E820_TYPE_RAM);
1236         }
1237 
1238         /* We just appended a lot of ranges, sanitize the table: */
1239         e820__update_table(e820_table);
1240 
1241         return who;
1242 }
1243 
1244 /*
1245  * Calls e820__memory_setup_default() in essence to pick up the firmware/bootloader
1246  * E820 map - with an optional platform quirk available for virtual platforms
1247  * to override this method of boot environment processing:
1248  */
1249 void __init e820__memory_setup(void)
1250 {
1251         char *who;
1252 
1253         /* This is a firmware interface ABI - make sure we don't break it: */
1254         BUILD_BUG_ON(sizeof(struct boot_e820_entry) != 20);
1255 
1256         who = x86_init.resources.memory_setup();
1257 
1258         memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec));
1259         memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
1260 
1261         pr_info("BIOS-provided physical RAM map:\n");
1262         e820__print_table(who);
1263 }
1264 
1265 void __init e820__memblock_setup(void)
1266 {
1267         int i;
1268         u64 end;
1269 
1270         /*
1271          * The bootstrap memblock region count maximum is 128 entries
1272          * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries
1273          * than that - so allow memblock resizing.
1274          *
1275          * This is safe, because this call happens pretty late during x86 setup,
1276          * so we know about reserved memory regions already. (This is important
1277          * so that memblock resizing does no stomp over reserved areas.)
1278          */
1279         memblock_allow_resize();
1280 
1281         for (i = 0; i < e820_table->nr_entries; i++) {
1282                 struct e820_entry *entry = &e820_table->entries[i];
1283 
1284                 end = entry->addr + entry->size;
1285                 if (end != (resource_size_t)end)
1286                         continue;
1287 
1288                 if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
1289                         continue;
1290 
1291                 memblock_add(entry->addr, entry->size);
1292         }
1293 
1294         /* Throw away partial pages: */
1295         memblock_trim_memory(PAGE_SIZE);
1296 
1297         memblock_dump_all();
1298 }
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root/arch/x86/kernel/e820.c

DEFINITIONS
