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