arch/arm/mm/init.c

   1 /*
   2  *  linux/arch/arm/mm/init.c
   3  *
   4  *  Copyright (C) 1995-2005 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/kernel.h>
  11 #include <linux/errno.h>
  12 #include <linux/swap.h>
  13 #include <linux/init.h>
  14 #include <linux/bootmem.h>
  15 #include <linux/mman.h>
  16 #include <linux/nodemask.h>
  17 #include <linux/initrd.h>
  18 #include <linux/highmem.h>
  19 #include <linux/gfp.h>
  20 #include <linux/memblock.h>
  21 #include <linux/sort.h>
  22
  23 #include <asm/mach-types.h>
  24 #include <asm/sections.h>
  25 #include <asm/setup.h>
  26 #include <asm/sizes.h>
  27 #include <asm/tlb.h>
  28 #include <asm/fixmap.h>
  29
  30 #include <asm/mach/arch.h>
  31 #include <asm/mach/map.h>
  32
  33 #include "mm.h"
  34
  35 static unsigned long phys_initrd_start __initdata = 0;
  36 static unsigned long phys_initrd_size __initdata = 0;
  37
  38 static int __init early_initrd(char *p)
  39 {
  40         unsigned long start, size;
  41         char *endp;
  42
  43         start = memparse(p, &endp);
  44         if (*endp == ',') {
  45                 size = memparse(endp + 1, NULL);
  46
  47                 phys_initrd_start = start;
  48                 phys_initrd_size = size;
  49         }
  50         return 0;
  51 }
  52 early_param("initrd", early_initrd);
  53
  54 static int __init parse_tag_initrd(const struct tag *tag)
  55 {
  56         printk(KERN_WARNING "ATAG_INITRD is deprecated; "
  57                 "please update your bootloader.\n");
  58         phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
  59         phys_initrd_size = tag->u.initrd.size;
  60         return 0;
  61 }
  62
  63 __tagtable(ATAG_INITRD, parse_tag_initrd);
  64
  65 static int __init parse_tag_initrd2(const struct tag *tag)
  66 {
  67         phys_initrd_start = tag->u.initrd.start;
  68         phys_initrd_size = tag->u.initrd.size;
  69         return 0;
  70 }
  71
  72 __tagtable(ATAG_INITRD2, parse_tag_initrd2);
  73
  74 /*
  75  * This keeps memory configuration data used by a couple memory
  76  * initialization functions, as well as show_mem() for the skipping
  77  * of holes in the memory map.  It is populated by arm_add_memory().
  78  */
  79 struct meminfo meminfo;
  80
  81 void show_mem(unsigned int filter)
  82 {
  83         int free = 0, total = 0, reserved = 0;
  84         int shared = 0, cached = 0, slab = 0, i;
  85         struct meminfo * mi = &meminfo;
  86
  87         printk("Mem-info:\n");
  88         show_free_areas();
  89
  90         for_each_bank (i, mi) {
  91                 struct membank *bank = &mi->bank[i];
  92                 unsigned int pfn1, pfn2;
  93                 struct page *page, *end;
  94
  95                 pfn1 = bank_pfn_start(bank);
  96                 pfn2 = bank_pfn_end(bank);
  97
  98                 page = pfn_to_page(pfn1);
  99                 end  = pfn_to_page(pfn2 - 1) + 1;
 100
 101                 do {
 102                         total++;
 103                         if (PageReserved(page))
 104                                 reserved++;
 105                         else if (PageSwapCache(page))
 106                                 cached++;
 107                         else if (PageSlab(page))
 108                                 slab++;
 109                         else if (!page_count(page))
 110                                 free++;
 111                         else
 112                                 shared += page_count(page) - 1;
 113                         page++;
 114                 } while (page < end);
 115         }
 116
 117         printk("%d pages of RAM\n", total);
 118         printk("%d free pages\n", free);
 119         printk("%d reserved pages\n", reserved);
 120         printk("%d slab pages\n", slab);
 121         printk("%d pages shared\n", shared);
 122         printk("%d pages swap cached\n", cached);
 123 }
 124
 125 static void __init find_limits(unsigned long *min, unsigned long *max_low,
 126         unsigned long *max_high)
 127 {
 128         struct meminfo *mi = &meminfo;
 129         int i;
 130
 131         *min = -1UL;
 132         *max_low = *max_high = 0;
 133
 134         for_each_bank (i, mi) {
 135                 struct membank *bank = &mi->bank[i];
 136                 unsigned long start, end;
 137
 138                 start = bank_pfn_start(bank);
 139                 end = bank_pfn_end(bank);
 140
 141                 if (*min > start)
 142                         *min = start;
 143                 if (*max_high < end)
 144                         *max_high = end;
 145                 if (bank->highmem)
 146                         continue;
 147                 if (*max_low < end)
 148                         *max_low = end;
 149         }
 150 }
 151
 152 static void __init arm_bootmem_init(unsigned long start_pfn,
 153         unsigned long end_pfn)
 154 {
 155         struct memblock_region *reg;
 156         unsigned int boot_pages;
 157         phys_addr_t bitmap;
 158         pg_data_t *pgdat;
 159
 160         /*
 161          * Allocate the bootmem bitmap page.  This must be in a region
 162          * of memory which has already been mapped.
 163          */
 164         boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
 165         bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
 166                                 __pfn_to_phys(end_pfn));
 167
 168         /*
 169          * Initialise the bootmem allocator, handing the
 170          * memory banks over to bootmem.
 171          */
 172         node_set_online(0);
 173         pgdat = NODE_DATA(0);
 174         init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);
 175
 176         /* Free the lowmem regions from memblock into bootmem. */
 177         for_each_memblock(memory, reg) {
 178                 unsigned long start = memblock_region_memory_base_pfn(reg);
 179                 unsigned long end = memblock_region_memory_end_pfn(reg);
 180
 181                 if (end >= end_pfn)
 182                         end = end_pfn;
 183                 if (start >= end)
 184                         break;
 185
 186                 free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT);
 187         }
 188
 189         /* Reserve the lowmem memblock reserved regions in bootmem. */
 190         for_each_memblock(reserved, reg) {
 191                 unsigned long start = memblock_region_reserved_base_pfn(reg);
 192                 unsigned long end = memblock_region_reserved_end_pfn(reg);
 193
 194                 if (end >= end_pfn)
 195                         end = end_pfn;
 196                 if (start >= end)
 197                         break;
 198
 199                 reserve_bootmem(__pfn_to_phys(start),
 200                                 (end - start) << PAGE_SHIFT, BOOTMEM_DEFAULT);
 201         }
 202 }
 203
 204 #ifdef CONFIG_ZONE_DMA
 205 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
 206         unsigned long dma_size)
 207 {
 208         if (size[0] <= dma_size)
 209                 return;
 210
 211         size[ZONE_NORMAL] = size[0] - dma_size;
 212         size[ZONE_DMA] = dma_size;
 213         hole[ZONE_NORMAL] = hole[0];
 214         hole[ZONE_DMA] = 0;
 215 }
 216 #endif
 217
 218 static void __init arm_bootmem_free(unsigned long min, unsigned long max_low,
 219         unsigned long max_high)
 220 {
 221         unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
 222         struct memblock_region *reg;
 223
 224         /*
 225          * initialise the zones.
 226          */
 227         memset(zone_size, 0, sizeof(zone_size));
 228
 229         /*
 230          * The memory size has already been determined.  If we need
 231          * to do anything fancy with the allocation of this memory
 232          * to the zones, now is the time to do it.
 233          */
 234         zone_size[0] = max_low - min;
 235 #ifdef CONFIG_HIGHMEM
 236         zone_size[ZONE_HIGHMEM] = max_high - max_low;
 237 #endif
 238
 239         /*
 240          * Calculate the size of the holes.
 241          *  holes = node_size - sum(bank_sizes)
 242          */
 243         memcpy(zhole_size, zone_size, sizeof(zhole_size));
 244         for_each_memblock(memory, reg) {
 245                 unsigned long start = memblock_region_memory_base_pfn(reg);
 246                 unsigned long end = memblock_region_memory_end_pfn(reg);
 247
 248                 if (start < max_low) {
 249                         unsigned long low_end = min(end, max_low);
 250                         zhole_size[0] -= low_end - start;
 251                 }
 252 #ifdef CONFIG_HIGHMEM
 253                 if (end > max_low) {
 254                         unsigned long high_start = max(start, max_low);
 255                         zhole_size[ZONE_HIGHMEM] -= end - high_start;
 256                 }
 257 #endif
 258         }
 259
 260 #ifdef ARM_DMA_ZONE_SIZE
 261 #ifndef CONFIG_ZONE_DMA
 262 #error ARM_DMA_ZONE_SIZE set but no DMA zone to limit allocations
 263 #endif
 264
 265         /*
 266          * Adjust the sizes according to any special requirements for
 267          * this machine type.
 268          */
 269         arm_adjust_dma_zone(zone_size, zhole_size,
 270                 ARM_DMA_ZONE_SIZE >> PAGE_SHIFT);
 271 #endif
 272
 273         free_area_init_node(0, zone_size, min, zhole_size);
 274 }
 275
 276 #ifndef CONFIG_SPARSEMEM
 277 int pfn_valid(unsigned long pfn)
 278 {
 279         return memblock_is_memory(pfn << PAGE_SHIFT);
 280 }
 281 EXPORT_SYMBOL(pfn_valid);
 282
 283 static void arm_memory_present(void)
 284 {
 285 }
 286 #else
 287 static void arm_memory_present(void)
 288 {
 289         struct memblock_region *reg;
 290
 291         for_each_memblock(memory, reg)
 292                 memory_present(0, memblock_region_memory_base_pfn(reg),
 293                                memblock_region_memory_end_pfn(reg));
 294 }
 295 #endif
 296
 297 static int __init meminfo_cmp(const void *_a, const void *_b)
 298 {
 299         const struct membank *a = _a, *b = _b;
 300         long cmp = bank_pfn_start(a) - bank_pfn_start(b);
 301         return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
 302 }
 303
 304 void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
 305 {
 306         int i;
 307
 308         sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL);
 309
 310         memblock_init();
 311         for (i = 0; i < mi->nr_banks; i++)
 312                 memblock_add(mi->bank[i].start, mi->bank[i].size);
 313
 314         /* Register the kernel text, kernel data and initrd with memblock. */
 315 #ifdef CONFIG_XIP_KERNEL
 316         memblock_reserve(__pa(_sdata), _end - _sdata);
 317 #else
 318         memblock_reserve(__pa(_stext), _end - _stext);
 319 #endif
 320 #ifdef CONFIG_BLK_DEV_INITRD
 321         if (phys_initrd_size &&
 322             memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) {
 323                 pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region - disabling initrd\n",
 324                        phys_initrd_start, phys_initrd_size);
 325                 phys_initrd_start = phys_initrd_size = 0;
 326         }
 327         if (phys_initrd_size) {
 328                 memblock_reserve(phys_initrd_start, phys_initrd_size);
 329
 330                 /* Now convert initrd to virtual addresses */
 331                 initrd_start = __phys_to_virt(phys_initrd_start);
 332                 initrd_end = initrd_start + phys_initrd_size;
 333         }
 334 #endif
 335
 336         arm_mm_memblock_reserve();
 337
 338         /* reserve any platform specific memblock areas */
 339         if (mdesc->reserve)
 340                 mdesc->reserve();
 341
 342         memblock_analyze();
 343         memblock_dump_all();
 344 }
 345
 346 void __init bootmem_init(void)
 347 {
 348         unsigned long min, max_low, max_high;
 349
 350         max_low = max_high = 0;
 351
 352         find_limits(&min, &max_low, &max_high);
 353
 354         arm_bootmem_init(min, max_low);
 355
 356         /*
 357          * Sparsemem tries to allocate bootmem in memory_present(),
 358          * so must be done after the fixed reservations
 359          */
 360         arm_memory_present();
 361
 362         /*
 363          * sparse_init() needs the bootmem allocator up and running.
 364          */
 365         sparse_init();
 366
 367         /*
 368          * Now free the memory - free_area_init_node needs
 369          * the sparse mem_map arrays initialized by sparse_init()
 370          * for memmap_init_zone(), otherwise all PFNs are invalid.
 371          */
 372         arm_bootmem_free(min, max_low, max_high);
 373
 374         high_memory = __va(((phys_addr_t)max_low << PAGE_SHIFT) - 1) + 1;
 375
 376         /*
 377          * This doesn't seem to be used by the Linux memory manager any
 378          * more, but is used by ll_rw_block.  If we can get rid of it, we
 379          * also get rid of some of the stuff above as well.
 380          *
 381          * Note: max_low_pfn and max_pfn reflect the number of _pages_ in
 382          * the system, not the maximum PFN.
 383          */
 384         max_low_pfn = max_low - PHYS_PFN_OFFSET;
 385         max_pfn = max_high - PHYS_PFN_OFFSET;
 386 }
 387
 388 static inline int free_area(unsigned long pfn, unsigned long end, char *s)
 389 {
 390         unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);
 391
 392         for (; pfn < end; pfn++) {
 393                 struct page *page = pfn_to_page(pfn);
 394                 ClearPageReserved(page);
 395                 init_page_count(page);
 396                 __free_page(page);
 397                 pages++;
 398         }
 399
 400         if (size && s)
 401                 printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
 402
 403         return pages;
 404 }
 405
 406 static inline void
 407 free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 408 {
 409         struct page *start_pg, *end_pg;
 410         unsigned long pg, pgend;
 411
 412         /*
 413          * Convert start_pfn/end_pfn to a struct page pointer.
 414          */
 415         start_pg = pfn_to_page(start_pfn - 1) + 1;
 416         end_pg = pfn_to_page(end_pfn);
 417
 418         /*
 419          * Convert to physical addresses, and
 420          * round start upwards and end downwards.
 421          */
 422         pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
 423         pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
 424
 425         /*
 426          * If there are free pages between these,
 427          * free the section of the memmap array.
 428          */
 429         if (pg < pgend)
 430                 free_bootmem(pg, pgend - pg);
 431 }
 432
 433 /*
 434  * The mem_map array can get very big.  Free the unused area of the memory map.
 435  */
 436 static void __init free_unused_memmap(struct meminfo *mi)
 437 {
 438         unsigned long bank_start, prev_bank_end = 0;
 439         unsigned int i;
 440
 441         /*
 442          * This relies on each bank being in address order.
 443          * The banks are sorted previously in bootmem_init().
 444          */
 445         for_each_bank(i, mi) {
 446                 struct membank *bank = &mi->bank[i];
 447
 448                 bank_start = bank_pfn_start(bank);
 449
 450                 /*
 451                  * If we had a previous bank, and there is a space
 452                  * between the current bank and the previous, free it.
 453                  */
 454                 if (prev_bank_end && prev_bank_end < bank_start)
 455                         free_memmap(prev_bank_end, bank_start);
 456
 457                 /*
 458                  * Align up here since the VM subsystem insists that the
 459                  * memmap entries are valid from the bank end aligned to
 460                  * MAX_ORDER_NR_PAGES.
 461                  */
 462                 prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES);
 463         }
 464 }
 465
 466 static void __init free_highpages(void)
 467 {
 468 #ifdef CONFIG_HIGHMEM
 469         unsigned long max_low = max_low_pfn + PHYS_PFN_OFFSET;
 470         struct memblock_region *mem, *res;
 471
 472         /* set highmem page free */
 473         for_each_memblock(memory, mem) {
 474                 unsigned long start = memblock_region_memory_base_pfn(mem);
 475                 unsigned long end = memblock_region_memory_end_pfn(mem);
 476
 477                 /* Ignore complete lowmem entries */
 478                 if (end <= max_low)
 479                         continue;
 480
 481                 /* Truncate partial highmem entries */
 482                 if (start < max_low)
 483                         start = max_low;
 484
 485                 /* Find and exclude any reserved regions */
 486                 for_each_memblock(reserved, res) {
 487                         unsigned long res_start, res_end;
 488
 489                         res_start = memblock_region_reserved_base_pfn(res);
 490                         res_end = memblock_region_reserved_end_pfn(res);
 491
 492                         if (res_end < start)
 493                                 continue;
 494                         if (res_start < start)
 495                                 res_start = start;
 496                         if (res_start > end)
 497                                 res_start = end;
 498                         if (res_end > end)
 499                                 res_end = end;
 500                         if (res_start != start)
 501                                 totalhigh_pages += free_area(start, res_start,
 502                                                              NULL);
 503                         start = res_end;
 504                         if (start == end)
 505                                 break;
 506                 }
 507
 508                 /* And now free anything which remains */
 509                 if (start < end)
 510                         totalhigh_pages += free_area(start, end, NULL);
 511         }
 512         totalram_pages += totalhigh_pages;
 513 #endif
 514 }
 515
 516 /*
 517  * mem_init() marks the free areas in the mem_map and tells us how much
 518  * memory is free.  This is done after various parts of the system have
 519  * claimed their memory after the kernel image.
 520  */
 521 void __init mem_init(void)
 522 {
 523         unsigned long reserved_pages, free_pages;
 524         struct memblock_region *reg;
 525         int i;
 526 #ifdef CONFIG_HAVE_TCM
 527         /* These pointers are filled in on TCM detection */
 528         extern u32 dtcm_end;
 529         extern u32 itcm_end;
 530 #endif
 531
 532         max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
 533
 534         /* this will put all unused low memory onto the freelists */
 535         free_unused_memmap(&meminfo);
 536
 537         totalram_pages += free_all_bootmem();
 538
 539 #ifdef CONFIG_SA1111
 540         /* now that our DMA memory is actually so designated, we can free it */
 541         totalram_pages += free_area(PHYS_PFN_OFFSET,
 542                                     __phys_to_pfn(__pa(swapper_pg_dir)), NULL);
 543 #endif
 544
 545         free_highpages();
 546
 547         reserved_pages = free_pages = 0;
 548
 549         for_each_bank(i, &meminfo) {
 550                 struct membank *bank = &meminfo.bank[i];
 551                 unsigned int pfn1, pfn2;
 552                 struct page *page, *end;
 553
 554                 pfn1 = bank_pfn_start(bank);
 555                 pfn2 = bank_pfn_end(bank);
 556
 557                 page = pfn_to_page(pfn1);
 558                 end  = pfn_to_page(pfn2 - 1) + 1;
 559
 560                 do {
 561                         if (PageReserved(page))
 562                                 reserved_pages++;
 563                         else if (!page_count(page))
 564                                 free_pages++;
 565                         page++;
 566                 } while (page < end);
 567         }
 568
 569         /*
 570          * Since our memory may not be contiguous, calculate the
 571          * real number of pages we have in this system
 572          */
 573         printk(KERN_INFO "Memory:");
 574         num_physpages = 0;
 575         for_each_memblock(memory, reg) {
 576                 unsigned long pages = memblock_region_memory_end_pfn(reg) -
 577                         memblock_region_memory_base_pfn(reg);
 578                 num_physpages += pages;
 579                 printk(" %ldMB", pages >> (20 - PAGE_SHIFT));
 580         }
 581         printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
 582
 583         printk(KERN_NOTICE "Memory: %luk/%luk available, %luk reserved, %luK highmem\n",
 584                 nr_free_pages() << (PAGE_SHIFT-10),
 585                 free_pages << (PAGE_SHIFT-10),
 586                 reserved_pages << (PAGE_SHIFT-10),
 587                 totalhigh_pages << (PAGE_SHIFT-10));
 588
 589 #define MLK(b, t) b, t, ((t) - (b)) >> 10
 590 #define MLM(b, t) b, t, ((t) - (b)) >> 20
 591 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
 592
 593         printk(KERN_NOTICE "Virtual kernel memory layout:\n"
 594                         "    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 595 #ifdef CONFIG_HAVE_TCM
 596                         "    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 597                         "    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 598 #endif
 599                         "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 600 #ifdef CONFIG_MMU
 601                         "    DMA     : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 602 #endif
 603                         "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 604                         "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 605 #ifdef CONFIG_HIGHMEM
 606                         "    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 607 #endif
 608                         "    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 609                         "      .init : 0x%p" " - 0x%p" "   (%4d kB)\n"
 610                         "      .text : 0x%p" " - 0x%p" "   (%4d kB)\n"
 611                         "      .data : 0x%p" " - 0x%p" "   (%4d kB)\n",
 612
 613                         MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
 614                                 (PAGE_SIZE)),
 615 #ifdef CONFIG_HAVE_TCM
 616                         MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
 617                         MLK(ITCM_OFFSET, (unsigned long) itcm_end),
 618 #endif
 619                         MLK(FIXADDR_START, FIXADDR_TOP),
 620 #ifdef CONFIG_MMU
 621                         MLM(CONSISTENT_BASE, CONSISTENT_END),
 622 #endif
 623                         MLM(VMALLOC_START, VMALLOC_END),
 624                         MLM(PAGE_OFFSET, (unsigned long)high_memory),
 625 #ifdef CONFIG_HIGHMEM
 626                         MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
 627                                 (PAGE_SIZE)),
 628 #endif
 629                         MLM(MODULES_VADDR, MODULES_END),
 630
 631                         MLK_ROUNDUP(__init_begin, __init_end),
 632                         MLK_ROUNDUP(_text, _etext),
 633                         MLK_ROUNDUP(_sdata, _edata));
 634
 635 #undef MLK
 636 #undef MLM
 637 #undef MLK_ROUNDUP
 638
 639         /*
 640          * Check boundaries twice: Some fundamental inconsistencies can
 641          * be detected at build time already.
 642          */
 643 #ifdef CONFIG_MMU
 644         BUILD_BUG_ON(VMALLOC_END                        > CONSISTENT_BASE);
 645         BUG_ON(VMALLOC_END                              > CONSISTENT_BASE);
 646
 647         BUILD_BUG_ON(TASK_SIZE                          > MODULES_VADDR);
 648         BUG_ON(TASK_SIZE                                > MODULES_VADDR);
 649 #endif
 650
 651 #ifdef CONFIG_HIGHMEM
 652         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
 653         BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE      > PAGE_OFFSET);
 654 #endif
 655
 656         if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
 657                 extern int sysctl_overcommit_memory;
 658                 /*
 659                  * On a machine this small we won't get
 660                  * anywhere without overcommit, so turn
 661                  * it on by default.
 662                  */
 663                 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 664         }
 665 }
 666
 667 void free_initmem(void)
 668 {
 669 #ifdef CONFIG_HAVE_TCM
 670         extern char __tcm_start, __tcm_end;
 671
 672         totalram_pages += free_area(__phys_to_pfn(__pa(&__tcm_start)),
 673                                     __phys_to_pfn(__pa(&__tcm_end)),
 674                                     "TCM link");
 675 #endif
 676
 677         if (!machine_is_integrator() && !machine_is_cintegrator())
 678                 totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
 679                                             __phys_to_pfn(__pa(__init_end)),
 680                                             "init");
 681 }
 682
 683 #ifdef CONFIG_BLK_DEV_INITRD
 684
 685 static int keep_initrd;
 686
 687 void free_initrd_mem(unsigned long start, unsigned long end)
 688 {
 689         if (!keep_initrd)
 690                 totalram_pages += free_area(__phys_to_pfn(__pa(start)),
 691                                             __phys_to_pfn(__pa(end)),
 692                                             "initrd");
 693 }
 694
 695 static int __init keepinitrd_setup(char *__unused)
 696 {
 697         keep_initrd = 1;
 698         return 1;
 699 }
 700
 701 __setup("keepinitrd", keepinitrd_setup);
 702 #endif