SAFE public projects git trees. - safe/jmp/linux-2.6/blob - arch/x86/mm/init_32.c

   1 /*
   2  *
   3  *  Copyright (C) 1995  Linus Torvalds
   4  *
   5  *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/signal.h>
  10 #include <linux/sched.h>
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/string.h>
  14 #include <linux/types.h>
  15 #include <linux/ptrace.h>
  16 #include <linux/mman.h>
  17 #include <linux/mm.h>
  18 #include <linux/hugetlb.h>
  19 #include <linux/swap.h>
  20 #include <linux/smp.h>
  21 #include <linux/init.h>
  22 #include <linux/highmem.h>
  23 #include <linux/pagemap.h>
  24 #include <linux/pci.h>
  25 #include <linux/pfn.h>
  26 #include <linux/poison.h>
  27 #include <linux/bootmem.h>
  28 #include <linux/slab.h>
  29 #include <linux/proc_fs.h>
  30 #include <linux/memory_hotplug.h>
  31 #include <linux/initrd.h>
  32 #include <linux/cpumask.h>
  33
  34 #include <asm/asm.h>
  35 #include <asm/bios_ebda.h>
  36 #include <asm/processor.h>
  37 #include <asm/system.h>
  38 #include <asm/uaccess.h>
  39 #include <asm/pgtable.h>
  40 #include <asm/dma.h>
  41 #include <asm/fixmap.h>
  42 #include <asm/e820.h>
  43 #include <asm/apic.h>
  44 #include <asm/bugs.h>
  45 #include <asm/tlb.h>
  46 #include <asm/tlbflush.h>
  47 #include <asm/pgalloc.h>
  48 #include <asm/sections.h>
  49 #include <asm/paravirt.h>
  50 #include <asm/setup.h>
  51 #include <asm/cacheflush.h>
  52 #include <asm/smp.h>
  53
  54 unsigned int __VMALLOC_RESERVE = 128 << 20;
  55
  56 unsigned long max_low_pfn_mapped;
  57 unsigned long max_pfn_mapped;
  58
  59 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  60 unsigned long highstart_pfn, highend_pfn;
  61
  62 static noinline int do_test_wp_bit(void);
  63
  64
  65 static unsigned long __initdata table_start;
  66 static unsigned long __meminitdata table_end;
  67 static unsigned long __meminitdata table_top;
  68
  69 static int __initdata after_init_bootmem;
  70
  71 static __init void *alloc_low_page(void)
  72 {
  73         unsigned long pfn = table_end++;
  74         void *adr;
  75
  76         if (pfn >= table_top)
  77                 panic("alloc_low_page: ran out of memory");
  78
  79         adr = __va(pfn * PAGE_SIZE);
  80         memset(adr, 0, PAGE_SIZE);
  81         return adr;
  82 }
  83
  84 /*
  85  * Creates a middle page table and puts a pointer to it in the
  86  * given global directory entry. This only returns the gd entry
  87  * in non-PAE compilation mode, since the middle layer is folded.
  88  */
  89 static pmd_t * __init one_md_table_init(pgd_t *pgd)
  90 {
  91         pud_t *pud;
  92         pmd_t *pmd_table;
  93
  94 #ifdef CONFIG_X86_PAE
  95         if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
  96                 if (after_init_bootmem)
  97                         pmd_table = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
  98                 else
  99                         pmd_table = (pmd_t *)alloc_low_page();
 100                 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
 101                 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
 102                 pud = pud_offset(pgd, 0);
 103                 BUG_ON(pmd_table != pmd_offset(pud, 0));
 104
 105                 return pmd_table;
 106         }
 107 #endif
 108         pud = pud_offset(pgd, 0);
 109         pmd_table = pmd_offset(pud, 0);
 110
 111         return pmd_table;
 112 }
 113
 114 /*
 115  * Create a page table and place a pointer to it in a middle page
 116  * directory entry:
 117  */
 118 static pte_t * __init one_page_table_init(pmd_t *pmd)
 119 {
 120         if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
 121                 pte_t *page_table = NULL;
 122
 123                 if (after_init_bootmem) {
 124 #ifdef CONFIG_DEBUG_PAGEALLOC
 125                         page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
 126 #endif
 127                         if (!page_table)
 128                                 page_table =
 129                                 (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
 130                 } else
 131                         page_table = (pte_t *)alloc_low_page();
 132
 133                 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
 134                 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
 135                 BUG_ON(page_table != pte_offset_kernel(pmd, 0));
 136         }
 137
 138         return pte_offset_kernel(pmd, 0);
 139 }
 140
 141 static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
 142                                            unsigned long vaddr, pte_t *lastpte)
 143 {
 144 #ifdef CONFIG_HIGHMEM
 145         /*
 146          * Something (early fixmap) may already have put a pte
 147          * page here, which causes the page table allocation
 148          * to become nonlinear. Attempt to fix it, and if it
 149          * is still nonlinear then we have to bug.
 150          */
 151         int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
 152         int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
 153
 154         if (pmd_idx_kmap_begin != pmd_idx_kmap_end
 155             && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin
 156             && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end
 157             && ((__pa(pte) >> PAGE_SHIFT) < table_start
 158                 || (__pa(pte) >> PAGE_SHIFT) >= table_end)) {
 159                 pte_t *newpte;
 160                 int i;
 161
 162                 BUG_ON(after_init_bootmem);
 163                 newpte = alloc_low_page();
 164                 for (i = 0; i < PTRS_PER_PTE; i++)
 165                         set_pte(newpte + i, pte[i]);
 166
 167                 paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT);
 168                 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
 169                 BUG_ON(newpte != pte_offset_kernel(pmd, 0));
 170                 __flush_tlb_all();
 171
 172                 paravirt_release_pte(__pa(pte) >> PAGE_SHIFT);
 173                 pte = newpte;
 174         }
 175         BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1)
 176                && vaddr > fix_to_virt(FIX_KMAP_END)
 177                && lastpte && lastpte + PTRS_PER_PTE != pte);
 178 #endif
 179         return pte;
 180 }
 181
 182 /*
 183  * This function initializes a certain range of kernel virtual memory
 184  * with new bootmem page tables, everywhere page tables are missing in
 185  * the given range.
 186  *
 187  * NOTE: The pagetables are allocated contiguous on the physical space
 188  * so we can cache the place of the first one and move around without
 189  * checking the pgd every time.
 190  */
 191 static void __init
 192 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
 193 {
 194         int pgd_idx, pmd_idx;
 195         unsigned long vaddr;
 196         pgd_t *pgd;
 197         pmd_t *pmd;
 198         pte_t *pte = NULL;
 199
 200         vaddr = start;
 201         pgd_idx = pgd_index(vaddr);
 202         pmd_idx = pmd_index(vaddr);
 203         pgd = pgd_base + pgd_idx;
 204
 205         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
 206                 pmd = one_md_table_init(pgd);
 207                 pmd = pmd + pmd_index(vaddr);
 208                 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
 209                                                         pmd++, pmd_idx++) {
 210                         pte = page_table_kmap_check(one_page_table_init(pmd),
 211                                                     pmd, vaddr, pte);
 212
 213                         vaddr += PMD_SIZE;
 214                 }
 215                 pmd_idx = 0;
 216         }
 217 }
 218
 219 static inline int is_kernel_text(unsigned long addr)
 220 {
 221         if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end)
 222                 return 1;
 223         return 0;
 224 }
 225
 226 /*
 227  * This maps the physical memory to kernel virtual address space, a total
 228  * of max_low_pfn pages, by creating page tables starting from address
 229  * PAGE_OFFSET:
 230  */
 231 static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
 232                                                 unsigned long start_pfn,
 233                                                 unsigned long end_pfn,
 234                                                 int use_pse)
 235 {
 236         int pgd_idx, pmd_idx, pte_ofs;
 237         unsigned long pfn;
 238         pgd_t *pgd;
 239         pmd_t *pmd;
 240         pte_t *pte;
 241         unsigned pages_2m, pages_4k;
 242         int mapping_iter;
 243
 244         /*
 245          * First iteration will setup identity mapping using large/small pages
 246          * based on use_pse, with other attributes same as set by
 247          * the early code in head_32.S
 248          *
 249          * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
 250          * as desired for the kernel identity mapping.
 251          *
 252          * This two pass mechanism conforms to the TLB app note which says:
 253          *
 254          *     "Software should not write to a paging-structure entry in a way
 255          *      that would change, for any linear address, both the page size
 256          *      and either the page frame or attributes."
 257          */
 258         mapping_iter = 1;
 259
 260         if (!cpu_has_pse)
 261                 use_pse = 0;
 262
 263 repeat:
 264         pages_2m = pages_4k = 0;
 265         pfn = start_pfn;
 266         pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
 267         pgd = pgd_base + pgd_idx;
 268         for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
 269                 pmd = one_md_table_init(pgd);
 270
 271                 if (pfn >= end_pfn)
 272                         continue;
 273 #ifdef CONFIG_X86_PAE
 274                 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
 275                 pmd += pmd_idx;
 276 #else
 277                 pmd_idx = 0;
 278 #endif
 279                 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
 280                      pmd++, pmd_idx++) {
 281                         unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
 282
 283                         /*
 284                          * Map with big pages if possible, otherwise
 285                          * create normal page tables:
 286                          */
 287                         if (use_pse) {
 288                                 unsigned int addr2;
 289                                 pgprot_t prot = PAGE_KERNEL_LARGE;
 290                                 /*
 291                                  * first pass will use the same initial
 292                                  * identity mapping attribute + _PAGE_PSE.
 293                                  */
 294                                 pgprot_t init_prot =
 295                                         __pgprot(PTE_IDENT_ATTR |
 296                                                  _PAGE_PSE);
 297
 298                                 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
 299                                         PAGE_OFFSET + PAGE_SIZE-1;
 300
 301                                 if (is_kernel_text(addr) ||
 302                                     is_kernel_text(addr2))
 303                                         prot = PAGE_KERNEL_LARGE_EXEC;
 304
 305                                 pages_2m++;
 306                                 if (mapping_iter == 1)
 307                                         set_pmd(pmd, pfn_pmd(pfn, init_prot));
 308                                 else
 309                                         set_pmd(pmd, pfn_pmd(pfn, prot));
 310
 311                                 pfn += PTRS_PER_PTE;
 312                                 continue;
 313                         }
 314                         pte = one_page_table_init(pmd);
 315
 316                         pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
 317                         pte += pte_ofs;
 318                         for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
 319                              pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
 320                                 pgprot_t prot = PAGE_KERNEL;
 321                                 /*
 322                                  * first pass will use the same initial
 323                                  * identity mapping attribute.
 324                                  */
 325                                 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
 326
 327                                 if (is_kernel_text(addr))
 328                                         prot = PAGE_KERNEL_EXEC;
 329
 330                                 pages_4k++;
 331                                 if (mapping_iter == 1)
 332                                         set_pte(pte, pfn_pte(pfn, init_prot));
 333                                 else
 334                                         set_pte(pte, pfn_pte(pfn, prot));
 335                         }
 336                 }
 337         }
 338         if (mapping_iter == 1) {
 339                 /*
 340                  * update direct mapping page count only in the first
 341                  * iteration.
 342                  */
 343                 update_page_count(PG_LEVEL_2M, pages_2m);
 344                 update_page_count(PG_LEVEL_4K, pages_4k);
 345
 346                 /*
 347                  * local global flush tlb, which will flush the previous
 348                  * mappings present in both small and large page TLB's.
 349                  */
 350                 __flush_tlb_all();
 351
 352                 /*
 353                  * Second iteration will set the actual desired PTE attributes.
 354                  */
 355                 mapping_iter = 2;
 356                 goto repeat;
 357         }
 358 }
 359
 360 /*
 361  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
 362  * is valid. The argument is a physical page number.
 363  *
 364  *
 365  * On x86, access has to be given to the first megabyte of ram because that area
 366  * contains bios code and data regions used by X and dosemu and similar apps.
 367  * Access has to be given to non-kernel-ram areas as well, these contain the PCI
 368  * mmio resources as well as potential bios/acpi data regions.
 369  */
 370 int devmem_is_allowed(unsigned long pagenr)
 371 {
 372         if (pagenr <= 256)
 373                 return 1;
 374         if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
 375                 return 0;
 376         if (!page_is_ram(pagenr))
 377                 return 1;
 378         return 0;
 379 }
 380
 381 pte_t *kmap_pte;
 382 pgprot_t kmap_prot;
 383
 384 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
 385 {
 386         return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
 387                         vaddr), vaddr), vaddr);
 388 }
 389
 390 static void __init kmap_init(void)
 391 {
 392         unsigned long kmap_vstart;
 393
 394         /*
 395          * Cache the first kmap pte:
 396          */
 397         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
 398         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
 399
 400         kmap_prot = PAGE_KERNEL;
 401 }
 402
 403 #ifdef CONFIG_HIGHMEM
 404 static void __init permanent_kmaps_init(pgd_t *pgd_base)
 405 {
 406         unsigned long vaddr;
 407         pgd_t *pgd;
 408         pud_t *pud;
 409         pmd_t *pmd;
 410         pte_t *pte;
 411
 412         vaddr = PKMAP_BASE;
 413         page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
 414
 415         pgd = swapper_pg_dir + pgd_index(vaddr);
 416         pud = pud_offset(pgd, vaddr);
 417         pmd = pmd_offset(pud, vaddr);
 418         pte = pte_offset_kernel(pmd, vaddr);
 419         pkmap_page_table = pte;
 420 }
 421
 422 static void __init add_one_highpage_init(struct page *page, int pfn)
 423 {
 424         ClearPageReserved(page);
 425         init_page_count(page);
 426         __free_page(page);
 427         totalhigh_pages++;
 428 }
 429
 430 struct add_highpages_data {
 431         unsigned long start_pfn;
 432         unsigned long end_pfn;
 433 };
 434
 435 static int __init add_highpages_work_fn(unsigned long start_pfn,
 436                                          unsigned long end_pfn, void *datax)
 437 {
 438         int node_pfn;
 439         struct page *page;
 440         unsigned long final_start_pfn, final_end_pfn;
 441         struct add_highpages_data *data;
 442
 443         data = (struct add_highpages_data *)datax;
 444
 445         final_start_pfn = max(start_pfn, data->start_pfn);
 446         final_end_pfn = min(end_pfn, data->end_pfn);
 447         if (final_start_pfn >= final_end_pfn)
 448                 return 0;
 449
 450         for (node_pfn = final_start_pfn; node_pfn < final_end_pfn;
 451              node_pfn++) {
 452                 if (!pfn_valid(node_pfn))
 453                         continue;
 454                 page = pfn_to_page(node_pfn);
 455                 add_one_highpage_init(page, node_pfn);
 456         }
 457
 458         return 0;
 459
 460 }
 461
 462 void __init add_highpages_with_active_regions(int nid, unsigned long start_pfn,
 463                                               unsigned long end_pfn)
 464 {
 465         struct add_highpages_data data;
 466
 467         data.start_pfn = start_pfn;
 468         data.end_pfn = end_pfn;
 469
 470         work_with_active_regions(nid, add_highpages_work_fn, &data);
 471 }
 472
 473 #ifndef CONFIG_NUMA
 474 static void __init set_highmem_pages_init(void)
 475 {
 476         add_highpages_with_active_regions(0, highstart_pfn, highend_pfn);
 477
 478         totalram_pages += totalhigh_pages;
 479 }
 480 #endif /* !CONFIG_NUMA */
 481
 482 #else
 483 static inline void permanent_kmaps_init(pgd_t *pgd_base)
 484 {
 485 }
 486 static inline void set_highmem_pages_init(void)
 487 {
 488 }
 489 #endif /* CONFIG_HIGHMEM */
 490
 491 void __init native_pagetable_setup_start(pgd_t *base)
 492 {
 493         unsigned long pfn, va;
 494         pgd_t *pgd;
 495         pud_t *pud;
 496         pmd_t *pmd;
 497         pte_t *pte;
 498
 499         /*
 500          * Remove any mappings which extend past the end of physical
 501          * memory from the boot time page table:
 502          */
 503         for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
 504                 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
 505                 pgd = base + pgd_index(va);
 506                 if (!pgd_present(*pgd))
 507                         break;
 508
 509                 pud = pud_offset(pgd, va);
 510                 pmd = pmd_offset(pud, va);
 511                 if (!pmd_present(*pmd))
 512                         break;
 513
 514                 pte = pte_offset_kernel(pmd, va);
 515                 if (!pte_present(*pte))
 516                         break;
 517
 518                 pte_clear(NULL, va, pte);
 519         }
 520         paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
 521 }
 522
 523 void __init native_pagetable_setup_done(pgd_t *base)
 524 {
 525 }
 526
 527 /*
 528  * Build a proper pagetable for the kernel mappings.  Up until this
 529  * point, we've been running on some set of pagetables constructed by
 530  * the boot process.
 531  *
 532  * If we're booting on native hardware, this will be a pagetable
 533  * constructed in arch/x86/kernel/head_32.S.  The root of the
 534  * pagetable will be swapper_pg_dir.
 535  *
 536  * If we're booting paravirtualized under a hypervisor, then there are
 537  * more options: we may already be running PAE, and the pagetable may
 538  * or may not be based in swapper_pg_dir.  In any case,
 539  * paravirt_pagetable_setup_start() will set up swapper_pg_dir
 540  * appropriately for the rest of the initialization to work.
 541  *
 542  * In general, pagetable_init() assumes that the pagetable may already
 543  * be partially populated, and so it avoids stomping on any existing
 544  * mappings.
 545  */
 546 static void __init early_ioremap_page_table_range_init(pgd_t *pgd_base)
 547 {
 548         unsigned long vaddr, end;
 549
 550         /*
 551          * Fixed mappings, only the page table structure has to be
 552          * created - mappings will be set by set_fixmap():
 553          */
 554         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 555         end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
 556         page_table_range_init(vaddr, end, pgd_base);
 557         early_ioremap_reset();
 558 }
 559
 560 static void __init pagetable_init(void)
 561 {
 562         pgd_t *pgd_base = swapper_pg_dir;
 563
 564         permanent_kmaps_init(pgd_base);
 565 }
 566
 567 #ifdef CONFIG_ACPI_SLEEP
 568 /*
 569  * ACPI suspend needs this for resume, because things like the intel-agp
 570  * driver might have split up a kernel 4MB mapping.
 571  */
 572 char swsusp_pg_dir[PAGE_SIZE]
 573         __attribute__ ((aligned(PAGE_SIZE)));
 574
 575 static inline void save_pg_dir(void)
 576 {
 577         memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE);
 578 }
 579 #else /* !CONFIG_ACPI_SLEEP */
 580 static inline void save_pg_dir(void)
 581 {
 582 }
 583 #endif /* !CONFIG_ACPI_SLEEP */
 584
 585 void zap_low_mappings(void)
 586 {
 587         int i;
 588
 589         /*
 590          * Zap initial low-memory mappings.
 591          *
 592          * Note that "pgd_clear()" doesn't do it for
 593          * us, because pgd_clear() is a no-op on i386.
 594          */
 595         for (i = 0; i < KERNEL_PGD_BOUNDARY; i++) {
 596 #ifdef CONFIG_X86_PAE
 597                 set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page)));
 598 #else
 599                 set_pgd(swapper_pg_dir+i, __pgd(0));
 600 #endif
 601         }
 602         flush_tlb_all();
 603 }
 604
 605 int nx_enabled;
 606
 607 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP);
 608 EXPORT_SYMBOL_GPL(__supported_pte_mask);
 609
 610 #ifdef CONFIG_X86_PAE
 611
 612 static int disable_nx __initdata;
 613
 614 /*
 615  * noexec = on|off
 616  *
 617  * Control non executable mappings.
 618  *
 619  * on      Enable
 620  * off     Disable
 621  */
 622 static int __init noexec_setup(char *str)
 623 {
 624         if (!str || !strcmp(str, "on")) {
 625                 if (cpu_has_nx) {
 626                         __supported_pte_mask |= _PAGE_NX;
 627                         disable_nx = 0;
 628                 }
 629         } else {
 630                 if (!strcmp(str, "off")) {
 631                         disable_nx = 1;
 632                         __supported_pte_mask &= ~_PAGE_NX;
 633                 } else {
 634                         return -EINVAL;
 635                 }
 636         }
 637
 638         return 0;
 639 }
 640 early_param("noexec", noexec_setup);
 641
 642 static void __init set_nx(void)
 643 {
 644         unsigned int v[4], l, h;
 645
 646         if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) {
 647                 cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]);
 648
 649                 if ((v[3] & (1 << 20)) && !disable_nx) {
 650                         rdmsr(MSR_EFER, l, h);
 651                         l |= EFER_NX;
 652                         wrmsr(MSR_EFER, l, h);
 653                         nx_enabled = 1;
 654                         __supported_pte_mask |= _PAGE_NX;
 655                 }
 656         }
 657 }
 658 #endif
 659
 660 /* user-defined highmem size */
 661 static unsigned int highmem_pages = -1;
 662
 663 /*
 664  * highmem=size forces highmem to be exactly 'size' bytes.
 665  * This works even on boxes that have no highmem otherwise.
 666  * This also works to reduce highmem size on bigger boxes.
 667  */
 668 static int __init parse_highmem(char *arg)
 669 {
 670         if (!arg)
 671                 return -EINVAL;
 672
 673         highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
 674         return 0;
 675 }
 676 early_param("highmem", parse_highmem);
 677
 678 #define MSG_HIGHMEM_TOO_BIG \
 679         "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
 680
 681 #define MSG_LOWMEM_TOO_SMALL \
 682         "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
 683 /*
 684  * All of RAM fits into lowmem - but if user wants highmem
 685  * artificially via the highmem=x boot parameter then create
 686  * it:
 687  */
 688 void __init lowmem_pfn_init(void)
 689 {
 690         if (highmem_pages == -1)
 691                 highmem_pages = 0;
 692 #ifdef CONFIG_HIGHMEM
 693         if (highmem_pages >= max_pfn) {
 694                 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG,
 695                         pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
 696                 highmem_pages = 0;
 697         }
 698         if (highmem_pages) {
 699                 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) {
 700                         printk(KERN_ERR MSG_LOWMEM_TOO_SMALL,
 701                                 pages_to_mb(highmem_pages));
 702                         highmem_pages = 0;
 703                 }
 704                 max_low_pfn -= highmem_pages;
 705         }
 706 #else
 707         if (highmem_pages)
 708                 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
 709 #endif
 710 }
 711
 712 #define MSG_HIGHMEM_TOO_SMALL \
 713         "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
 714
 715 #define MSG_HIGHMEM_TRIMMED \
 716         "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
 717 /*
 718  * We have more RAM than fits into lowmem - we try to put it into
 719  * highmem, also taking the highmem=x boot parameter into account:
 720  */
 721 void __init highmem_pfn_init(void)
 722 {
 723         if (highmem_pages == -1)
 724                 highmem_pages = max_pfn - MAXMEM_PFN;
 725
 726         if (highmem_pages + MAXMEM_PFN < max_pfn)
 727                 max_pfn = MAXMEM_PFN + highmem_pages;
 728
 729         if (highmem_pages + MAXMEM_PFN > max_pfn) {
 730                 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL,
 731                         pages_to_mb(max_pfn - MAXMEM_PFN),
 732                         pages_to_mb(highmem_pages));
 733                 highmem_pages = 0;
 734         }
 735         max_low_pfn = MAXMEM_PFN;
 736 #ifndef CONFIG_HIGHMEM
 737         /* Maximum memory usable is what is directly addressable */
 738         printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20);
 739         if (max_pfn > MAX_NONPAE_PFN)
 740                 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
 741         else
 742                 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
 743         max_pfn = MAXMEM_PFN;
 744 #else /* !CONFIG_HIGHMEM */
 745 #ifndef CONFIG_HIGHMEM64G
 746         if (max_pfn > MAX_NONPAE_PFN) {
 747                 max_pfn = MAX_NONPAE_PFN;
 748                 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED);
 749         }
 750 #endif /* !CONFIG_HIGHMEM64G */
 751 #endif /* !CONFIG_HIGHMEM */
 752 }
 753
 754 /*
 755  * Determine low and high memory ranges:
 756  */
 757 void __init find_low_pfn_range(void)
 758 {
 759         /* it could update max_pfn */
 760
 761         /* max_low_pfn is 0, we already have early_res support */
 762         max_low_pfn = max_pfn;
 763
 764         if (max_low_pfn > MAXMEM_PFN)
 765                 highmem_pfn_init();
 766         else
 767                 lowmem_pfn_init();
 768 }
 769
 770 #ifndef CONFIG_NEED_MULTIPLE_NODES
 771 void __init initmem_init(unsigned long start_pfn,
 772                                   unsigned long end_pfn)
 773 {
 774 #ifdef CONFIG_HIGHMEM
 775         highstart_pfn = highend_pfn = max_pfn;
 776         if (max_pfn > max_low_pfn)
 777                 highstart_pfn = max_low_pfn;
 778         memory_present(0, 0, highend_pfn);
 779         e820_register_active_regions(0, 0, highend_pfn);
 780         printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
 781                 pages_to_mb(highend_pfn - highstart_pfn));
 782         num_physpages = highend_pfn;
 783         high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
 784 #else
 785         memory_present(0, 0, max_low_pfn);
 786         e820_register_active_regions(0, 0, max_low_pfn);
 787         num_physpages = max_low_pfn;
 788         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
 789 #endif
 790 #ifdef CONFIG_FLATMEM
 791         max_mapnr = num_physpages;
 792 #endif
 793         printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
 794                         pages_to_mb(max_low_pfn));
 795
 796         setup_bootmem_allocator();
 797 }
 798 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 799
 800 static void __init zone_sizes_init(void)
 801 {
 802         unsigned long max_zone_pfns[MAX_NR_ZONES];
 803         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 804         max_zone_pfns[ZONE_DMA] =
 805                 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
 806         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 807 #ifdef CONFIG_HIGHMEM
 808         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 809 #endif
 810
 811         free_area_init_nodes(max_zone_pfns);
 812 }
 813
 814 void __init setup_bootmem_allocator(void)
 815 {
 816         int i;
 817         unsigned long bootmap_size, bootmap;
 818         /*
 819          * Initialize the boot-time allocator (with low memory only):
 820          */
 821         bootmap_size = bootmem_bootmap_pages(max_low_pfn)<<PAGE_SHIFT;
 822         bootmap = find_e820_area(min_low_pfn<<PAGE_SHIFT,
 823                                  max_pfn_mapped<<PAGE_SHIFT, bootmap_size,
 824                                  PAGE_SIZE);
 825         if (bootmap == -1L)
 826                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
 827         reserve_early(bootmap, bootmap + bootmap_size, "BOOTMAP");
 828
 829         /* don't touch min_low_pfn */
 830         bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
 831                                          min_low_pfn, max_low_pfn);
 832         printk(KERN_INFO "  mapped low ram: 0 - %08lx\n",
 833                  max_pfn_mapped<<PAGE_SHIFT);
 834         printk(KERN_INFO "  low ram: %08lx - %08lx\n",
 835                  min_low_pfn<<PAGE_SHIFT, max_low_pfn<<PAGE_SHIFT);
 836         printk(KERN_INFO "  bootmap %08lx - %08lx\n",
 837                  bootmap, bootmap + bootmap_size);
 838         for_each_online_node(i)
 839                 free_bootmem_with_active_regions(i, max_low_pfn);
 840         early_res_to_bootmem(0, max_low_pfn<<PAGE_SHIFT);
 841
 842         after_init_bootmem = 1;
 843 }
 844
 845 static void __init find_early_table_space(unsigned long end, int use_pse)
 846 {
 847         unsigned long puds, pmds, ptes, tables, start;
 848
 849         puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
 850         tables = PAGE_ALIGN(puds * sizeof(pud_t));
 851
 852         pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
 853         tables += PAGE_ALIGN(pmds * sizeof(pmd_t));
 854
 855         if (use_pse) {
 856                 unsigned long extra;
 857
 858                 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
 859                 extra += PMD_SIZE;
 860                 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
 861         } else
 862                 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
 863
 864         tables += PAGE_ALIGN(ptes * sizeof(pte_t));
 865
 866         /* for fixmap */
 867         tables += PAGE_ALIGN(__end_of_fixed_addresses * sizeof(pte_t));
 868
 869         /*
 870          * RED-PEN putting page tables only on node 0 could
 871          * cause a hotspot and fill up ZONE_DMA. The page tables
 872          * need roughly 0.5KB per GB.
 873          */
 874         start = 0x7000;
 875         table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT,
 876                                         tables, PAGE_SIZE);
 877         if (table_start == -1UL)
 878                 panic("Cannot find space for the kernel page tables");
 879
 880         table_start >>= PAGE_SHIFT;
 881         table_end = table_start;
 882         table_top = table_start + (tables>>PAGE_SHIFT);
 883
 884         printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
 885                 end, table_start << PAGE_SHIFT,
 886                 (table_start << PAGE_SHIFT) + tables);
 887 }
 888
 889 unsigned long __init_refok init_memory_mapping(unsigned long start,
 890                                                 unsigned long end)
 891 {
 892         pgd_t *pgd_base = swapper_pg_dir;
 893         unsigned long start_pfn, end_pfn;
 894         unsigned long big_page_start;
 895 #ifdef CONFIG_DEBUG_PAGEALLOC
 896         /*
 897          * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
 898          * This will simplify cpa(), which otherwise needs to support splitting
 899          * large pages into small in interrupt context, etc.
 900          */
 901         int use_pse = 0;
 902 #else
 903         int use_pse = cpu_has_pse;
 904 #endif
 905
 906         /*
 907          * Find space for the kernel direct mapping tables.
 908          */
 909         if (!after_init_bootmem)
 910                 find_early_table_space(end, use_pse);
 911
 912 #ifdef CONFIG_X86_PAE
 913         set_nx();
 914         if (nx_enabled)
 915                 printk(KERN_INFO "NX (Execute Disable) protection: active\n");
 916 #endif
 917
 918         /* Enable PSE if available */
 919         if (cpu_has_pse)
 920                 set_in_cr4(X86_CR4_PSE);
 921
 922         /* Enable PGE if available */
 923         if (cpu_has_pge) {
 924                 set_in_cr4(X86_CR4_PGE);
 925                 __supported_pte_mask |= _PAGE_GLOBAL;
 926         }
 927
 928         /*
 929          * Don't use a large page for the first 2/4MB of memory
 930          * because there are often fixed size MTRRs in there
 931          * and overlapping MTRRs into large pages can cause
 932          * slowdowns.
 933          */
 934         big_page_start = PMD_SIZE;
 935
 936         if (start < big_page_start) {
 937                 start_pfn = start >> PAGE_SHIFT;
 938                 end_pfn = min(big_page_start>>PAGE_SHIFT, end>>PAGE_SHIFT);
 939         } else {
 940                 /* head is not big page alignment ? */
 941                 start_pfn = start >> PAGE_SHIFT;
 942                 end_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
 943                                  << (PMD_SHIFT - PAGE_SHIFT);
 944         }
 945         if (start_pfn < end_pfn)
 946                 kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn, 0);
 947
 948         /* big page range */
 949         start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
 950                          << (PMD_SHIFT - PAGE_SHIFT);
 951         if (start_pfn < (big_page_start >> PAGE_SHIFT))
 952                 start_pfn =  big_page_start >> PAGE_SHIFT;
 953         end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
 954         if (start_pfn < end_pfn)
 955                 kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn,
 956                                              use_pse);
 957
 958         /* tail is not big page alignment ? */
 959         start_pfn = end_pfn;
 960         if (start_pfn > (big_page_start>>PAGE_SHIFT)) {
 961                 end_pfn = end >> PAGE_SHIFT;
 962                 if (start_pfn < end_pfn)
 963                         kernel_physical_mapping_init(pgd_base, start_pfn,
 964                                                          end_pfn, 0);
 965         }
 966
 967         early_ioremap_page_table_range_init(pgd_base);
 968
 969         load_cr3(swapper_pg_dir);
 970
 971         __flush_tlb_all();
 972
 973         if (!after_init_bootmem)
 974                 reserve_early(table_start << PAGE_SHIFT,
 975                                  table_end << PAGE_SHIFT, "PGTABLE");
 976
 977         if (!after_init_bootmem)
 978                 early_memtest(start, end);
 979
 980         return end >> PAGE_SHIFT;
 981 }
 982
 983
 984 /*
 985  * paging_init() sets up the page tables - note that the first 8MB are
 986  * already mapped by head.S.
 987  *
 988  * This routines also unmaps the page at virtual kernel address 0, so
 989  * that we can trap those pesky NULL-reference errors in the kernel.
 990  */
 991 void __init paging_init(void)
 992 {
 993         pagetable_init();
 994
 995         __flush_tlb_all();
 996
 997         kmap_init();
 998
 999         /*
1000          * NOTE: at this point the bootmem allocator is fully available.
1001          */
1002         sparse_init();
1003         zone_sizes_init();
1004 }
1005
1006 /*
1007  * Test if the WP bit works in supervisor mode. It isn't supported on 386's
1008  * and also on some strange 486's. All 586+'s are OK. This used to involve
1009  * black magic jumps to work around some nasty CPU bugs, but fortunately the
1010  * switch to using exceptions got rid of all that.
1011  */
1012 static void __init test_wp_bit(void)
1013 {
1014         printk(KERN_INFO
1015   "Checking if this processor honours the WP bit even in supervisor mode...");
1016
1017         /* Any page-aligned address will do, the test is non-destructive */
1018         __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY);
1019         boot_cpu_data.wp_works_ok = do_test_wp_bit();
1020         clear_fixmap(FIX_WP_TEST);
1021
1022         if (!boot_cpu_data.wp_works_ok) {
1023                 printk(KERN_CONT "No.\n");
1024 #ifdef CONFIG_X86_WP_WORKS_OK
1025                 panic(
1026   "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
1027 #endif
1028         } else {
1029                 printk(KERN_CONT "Ok.\n");
1030         }
1031 }
1032
1033 static struct kcore_list kcore_mem, kcore_vmalloc;
1034
1035 void __init mem_init(void)
1036 {
1037         int codesize, reservedpages, datasize, initsize;
1038         int tmp;
1039
1040         pci_iommu_alloc();
1041
1042 #ifdef CONFIG_FLATMEM
1043         BUG_ON(!mem_map);
1044 #endif
1045         /* this will put all low memory onto the freelists */
1046         totalram_pages += free_all_bootmem();
1047
1048         reservedpages = 0;
1049         for (tmp = 0; tmp < max_low_pfn; tmp++)
1050                 /*
1051                  * Only count reserved RAM pages:
1052                  */
1053                 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp)))
1054                         reservedpages++;
1055
1056         set_highmem_pages_init();
1057
1058         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
1059         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
1060         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
1061
1062         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
1063         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
1064                    VMALLOC_END-VMALLOC_START);
1065
1066         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
1067                         "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
1068                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
1069                 num_physpages << (PAGE_SHIFT-10),
1070                 codesize >> 10,
1071                 reservedpages << (PAGE_SHIFT-10),
1072                 datasize >> 10,
1073                 initsize >> 10,
1074                 (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10))
1075                );
1076
1077         printk(KERN_INFO "virtual kernel memory layout:\n"
1078                 "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
1079 #ifdef CONFIG_HIGHMEM
1080                 "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
1081 #endif
1082                 "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
1083                 "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
1084                 "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
1085                 "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
1086                 "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
1087                 FIXADDR_START, FIXADDR_TOP,
1088                 (FIXADDR_TOP - FIXADDR_START) >> 10,
1089
1090 #ifdef CONFIG_HIGHMEM
1091                 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
1092                 (LAST_PKMAP*PAGE_SIZE) >> 10,
1093 #endif
1094
1095                 VMALLOC_START, VMALLOC_END,
1096                 (VMALLOC_END - VMALLOC_START) >> 20,
1097
1098                 (unsigned long)__va(0), (unsigned long)high_memory,
1099                 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
1100
1101                 (unsigned long)&__init_begin, (unsigned long)&__init_end,
1102                 ((unsigned long)&__init_end -
1103                  (unsigned long)&__init_begin) >> 10,
1104
1105                 (unsigned long)&_etext, (unsigned long)&_edata,
1106                 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
1107
1108                 (unsigned long)&_text, (unsigned long)&_etext,
1109                 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
1110
1111         /*
1112          * Check boundaries twice: Some fundamental inconsistencies can
1113          * be detected at build time already.
1114          */
1115 #define __FIXADDR_TOP (-PAGE_SIZE)
1116 #ifdef CONFIG_HIGHMEM
1117         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE  > FIXADDR_START);
1118         BUILD_BUG_ON(VMALLOC_END                        > PKMAP_BASE);
1119 #endif
1120 #define high_memory (-128UL << 20)
1121         BUILD_BUG_ON(VMALLOC_START                      >= VMALLOC_END);
1122 #undef high_memory
1123 #undef __FIXADDR_TOP
1124
1125 #ifdef CONFIG_HIGHMEM
1126         BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE        > FIXADDR_START);
1127         BUG_ON(VMALLOC_END                              > PKMAP_BASE);
1128 #endif
1129         BUG_ON(VMALLOC_START                            >= VMALLOC_END);
1130         BUG_ON((unsigned long)high_memory               > VMALLOC_START);
1131
1132         if (boot_cpu_data.wp_works_ok < 0)
1133                 test_wp_bit();
1134
1135         save_pg_dir();
1136         zap_low_mappings();
1137 }
1138
1139 #ifdef CONFIG_MEMORY_HOTPLUG
1140 int arch_add_memory(int nid, u64 start, u64 size)
1141 {
1142         struct pglist_data *pgdata = NODE_DATA(nid);
1143         struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM;
1144         unsigned long start_pfn = start >> PAGE_SHIFT;
1145         unsigned long nr_pages = size >> PAGE_SHIFT;
1146
1147         return __add_pages(nid, zone, start_pfn, nr_pages);
1148 }
1149 #endif
1150
1151 /*
1152  * This function cannot be __init, since exceptions don't work in that
1153  * section.  Put this after the callers, so that it cannot be inlined.
1154  */
1155 static noinline int do_test_wp_bit(void)
1156 {
1157         char tmp_reg;
1158         int flag;
1159
1160         __asm__ __volatile__(
1161                 "       movb %0, %1     \n"
1162                 "1:     movb %1, %0     \n"
1163                 "       xorl %2, %2     \n"
1164                 "2:                     \n"
1165                 _ASM_EXTABLE(1b,2b)
1166                 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
1167                  "=q" (tmp_reg),
1168                  "=r" (flag)
1169                 :"2" (1)
1170                 :"memory");
1171
1172         return flag;
1173 }
1174
1175 #ifdef CONFIG_DEBUG_RODATA
1176 const int rodata_test_data = 0xC3;
1177 EXPORT_SYMBOL_GPL(rodata_test_data);
1178
1179 void mark_rodata_ro(void)
1180 {
1181         unsigned long start = PFN_ALIGN(_text);
1182         unsigned long size = PFN_ALIGN(_etext) - start;
1183
1184 #ifndef CONFIG_DYNAMIC_FTRACE
1185         /* Dynamic tracing modifies the kernel text section */
1186         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1187         printk(KERN_INFO "Write protecting the kernel text: %luk\n",
1188                 size >> 10);
1189
1190 #ifdef CONFIG_CPA_DEBUG
1191         printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
1192                 start, start+size);
1193         set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
1194
1195         printk(KERN_INFO "Testing CPA: write protecting again\n");
1196         set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
1197 #endif
1198 #endif /* CONFIG_DYNAMIC_FTRACE */
1199
1200         start += size;
1201         size = (unsigned long)__end_rodata - start;
1202         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1203         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1204                 size >> 10);
1205         rodata_test();
1206
1207 #ifdef CONFIG_CPA_DEBUG
1208         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
1209         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
1210
1211         printk(KERN_INFO "Testing CPA: write protecting again\n");
1212         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1213 #endif
1214 }
1215 #endif
1216
1217 void free_init_pages(char *what, unsigned long begin, unsigned long end)
1218 {
1219 #ifdef CONFIG_DEBUG_PAGEALLOC
1220         /*
1221          * If debugging page accesses then do not free this memory but
1222          * mark them not present - any buggy init-section access will
1223          * create a kernel page fault:
1224          */
1225         printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
1226                 begin, PAGE_ALIGN(end));
1227         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
1228 #else
1229         unsigned long addr;
1230
1231         /*
1232          * We just marked the kernel text read only above, now that
1233          * we are going to free part of that, we need to make that
1234          * writeable first.
1235          */
1236         set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
1237
1238         for (addr = begin; addr < end; addr += PAGE_SIZE) {
1239                 ClearPageReserved(virt_to_page(addr));
1240                 init_page_count(virt_to_page(addr));
1241                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
1242                 free_page(addr);
1243                 totalram_pages++;
1244         }
1245         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
1246 #endif
1247 }
1248
1249 void free_initmem(void)
1250 {
1251         free_init_pages("unused kernel memory",
1252                         (unsigned long)(&__init_begin),
1253                         (unsigned long)(&__init_end));
1254 }
1255
1256 #ifdef CONFIG_BLK_DEV_INITRD
1257 void free_initrd_mem(unsigned long start, unsigned long end)
1258 {
1259         free_init_pages("initrd memory", start, end);
1260 }
1261 #endif
1262
1263 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
1264                                    int flags)
1265 {
1266         return reserve_bootmem(phys, len, flags);
1267 }