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/pfn.h>
  25 #include <linux/poison.h>
  26 #include <linux/bootmem.h>
  27 #include <linux/slab.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/memory_hotplug.h>
  30 #include <linux/initrd.h>
  31 #include <linux/cpumask.h>
  32
  33 #include <asm/asm.h>
  34 #include <asm/processor.h>
  35 #include <asm/system.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/pgtable.h>
  38 #include <asm/dma.h>
  39 #include <asm/fixmap.h>
  40 #include <asm/e820.h>
  41 #include <asm/apic.h>
  42 #include <asm/bugs.h>
  43 #include <asm/tlb.h>
  44 #include <asm/tlbflush.h>
  45 #include <asm/pgalloc.h>
  46 #include <asm/sections.h>
  47 #include <asm/paravirt.h>
  48 #include <asm/setup.h>
  49 #include <asm/cacheflush.h>
  50
  51 unsigned int __VMALLOC_RESERVE = 128 << 20;
  52
  53 unsigned long max_pfn_mapped;
  54
  55 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  56 unsigned long highstart_pfn, highend_pfn;
  57
  58 static noinline int do_test_wp_bit(void);
  59
  60 /*
  61  * Creates a middle page table and puts a pointer to it in the
  62  * given global directory entry. This only returns the gd entry
  63  * in non-PAE compilation mode, since the middle layer is folded.
  64  */
  65 static pmd_t * __init one_md_table_init(pgd_t *pgd)
  66 {
  67         pud_t *pud;
  68         pmd_t *pmd_table;
  69
  70 #ifdef CONFIG_X86_PAE
  71         if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
  72                 pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
  73
  74                 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
  75                 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
  76                 pud = pud_offset(pgd, 0);
  77                 BUG_ON(pmd_table != pmd_offset(pud, 0));
  78         }
  79 #endif
  80         pud = pud_offset(pgd, 0);
  81         pmd_table = pmd_offset(pud, 0);
  82
  83         return pmd_table;
  84 }
  85
  86 /*
  87  * Create a page table and place a pointer to it in a middle page
  88  * directory entry:
  89  */
  90 static pte_t * __init one_page_table_init(pmd_t *pmd)
  91 {
  92         if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
  93                 pte_t *page_table = NULL;
  94
  95 #ifdef CONFIG_DEBUG_PAGEALLOC
  96                 page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
  97 #endif
  98                 if (!page_table) {
  99                         page_table =
 100                                 (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
 101                 }
 102
 103                 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
 104                 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
 105                 BUG_ON(page_table != pte_offset_kernel(pmd, 0));
 106         }
 107
 108         return pte_offset_kernel(pmd, 0);
 109 }
 110
 111 /*
 112  * This function initializes a certain range of kernel virtual memory
 113  * with new bootmem page tables, everywhere page tables are missing in
 114  * the given range.
 115  *
 116  * NOTE: The pagetables are allocated contiguous on the physical space
 117  * so we can cache the place of the first one and move around without
 118  * checking the pgd every time.
 119  */
 120 static void __init
 121 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
 122 {
 123         int pgd_idx, pmd_idx;
 124         unsigned long vaddr;
 125         pgd_t *pgd;
 126         pmd_t *pmd;
 127
 128         vaddr = start;
 129         pgd_idx = pgd_index(vaddr);
 130         pmd_idx = pmd_index(vaddr);
 131         pgd = pgd_base + pgd_idx;
 132
 133         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
 134                 pmd = one_md_table_init(pgd);
 135                 pmd = pmd + pmd_index(vaddr);
 136                 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
 137                                                         pmd++, pmd_idx++) {
 138                         one_page_table_init(pmd);
 139
 140                         vaddr += PMD_SIZE;
 141                 }
 142                 pmd_idx = 0;
 143         }
 144 }
 145
 146 static inline int is_kernel_text(unsigned long addr)
 147 {
 148         if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end)
 149                 return 1;
 150         return 0;
 151 }
 152
 153 /*
 154  * This maps the physical memory to kernel virtual address space, a total
 155  * of max_low_pfn pages, by creating page tables starting from address
 156  * PAGE_OFFSET:
 157  */
 158 static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
 159 {
 160         int pgd_idx, pmd_idx, pte_ofs;
 161         unsigned long pfn;
 162         pgd_t *pgd;
 163         pmd_t *pmd;
 164         pte_t *pte;
 165
 166         pgd_idx = pgd_index(PAGE_OFFSET);
 167         pgd = pgd_base + pgd_idx;
 168         pfn = 0;
 169
 170         for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
 171                 pmd = one_md_table_init(pgd);
 172                 if (pfn >= max_low_pfn)
 173                         continue;
 174
 175                 for (pmd_idx = 0;
 176                      pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn;
 177                      pmd++, pmd_idx++) {
 178                         unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
 179
 180                         /*
 181                          * Map with big pages if possible, otherwise
 182                          * create normal page tables:
 183                          *
 184                          * Don't use a large page for the first 2/4MB of memory
 185                          * because there are often fixed size MTRRs in there
 186                          * and overlapping MTRRs into large pages can cause
 187                          * slowdowns.
 188                          */
 189                         if (cpu_has_pse && !(pgd_idx == 0 && pmd_idx == 0)) {
 190                                 unsigned int addr2;
 191                                 pgprot_t prot = PAGE_KERNEL_LARGE;
 192
 193                                 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
 194                                         PAGE_OFFSET + PAGE_SIZE-1;
 195
 196                                 if (is_kernel_text(addr) ||
 197                                     is_kernel_text(addr2))
 198                                         prot = PAGE_KERNEL_LARGE_EXEC;
 199
 200                                 set_pmd(pmd, pfn_pmd(pfn, prot));
 201
 202                                 pfn += PTRS_PER_PTE;
 203                                 max_pfn_mapped = pfn;
 204                                 continue;
 205                         }
 206                         pte = one_page_table_init(pmd);
 207
 208                         for (pte_ofs = 0;
 209                              pte_ofs < PTRS_PER_PTE && pfn < max_low_pfn;
 210                              pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
 211                                 pgprot_t prot = PAGE_KERNEL;
 212
 213                                 if (is_kernel_text(addr))
 214                                         prot = PAGE_KERNEL_EXEC;
 215
 216                                 set_pte(pte, pfn_pte(pfn, prot));
 217                         }
 218                         max_pfn_mapped = pfn;
 219                 }
 220         }
 221 }
 222
 223 static inline int page_kills_ppro(unsigned long pagenr)
 224 {
 225         if (pagenr >= 0x70000 && pagenr <= 0x7003F)
 226                 return 1;
 227         return 0;
 228 }
 229
 230 /*
 231  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
 232  * is valid. The argument is a physical page number.
 233  *
 234  *
 235  * On x86, access has to be given to the first megabyte of ram because that area
 236  * contains bios code and data regions used by X and dosemu and similar apps.
 237  * Access has to be given to non-kernel-ram areas as well, these contain the PCI
 238  * mmio resources as well as potential bios/acpi data regions.
 239  */
 240 int devmem_is_allowed(unsigned long pagenr)
 241 {
 242         if (pagenr <= 256)
 243                 return 1;
 244         if (!page_is_ram(pagenr))
 245                 return 1;
 246         return 0;
 247 }
 248
 249 #ifdef CONFIG_HIGHMEM
 250 pte_t *kmap_pte;
 251 pgprot_t kmap_prot;
 252
 253 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
 254 {
 255         return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
 256                         vaddr), vaddr), vaddr);
 257 }
 258
 259 static void __init kmap_init(void)
 260 {
 261         unsigned long kmap_vstart;
 262
 263         /*
 264          * Cache the first kmap pte:
 265          */
 266         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
 267         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
 268
 269         kmap_prot = PAGE_KERNEL;
 270 }
 271
 272 static void __init permanent_kmaps_init(pgd_t *pgd_base)
 273 {
 274         unsigned long vaddr;
 275         pgd_t *pgd;
 276         pud_t *pud;
 277         pmd_t *pmd;
 278         pte_t *pte;
 279
 280         vaddr = PKMAP_BASE;
 281         page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
 282
 283         pgd = swapper_pg_dir + pgd_index(vaddr);
 284         pud = pud_offset(pgd, vaddr);
 285         pmd = pmd_offset(pud, vaddr);
 286         pte = pte_offset_kernel(pmd, vaddr);
 287         pkmap_page_table = pte;
 288 }
 289
 290 void __init add_one_highpage_init(struct page *page, int pfn, int bad_ppro)
 291 {
 292         if (page_is_ram(pfn) && !(bad_ppro && page_kills_ppro(pfn))) {
 293                 ClearPageReserved(page);
 294                 init_page_count(page);
 295                 __free_page(page);
 296                 totalhigh_pages++;
 297         } else
 298                 SetPageReserved(page);
 299 }
 300
 301 #ifndef CONFIG_NUMA
 302 static void __init set_highmem_pages_init(int bad_ppro)
 303 {
 304         int pfn;
 305
 306         for (pfn = highstart_pfn; pfn < highend_pfn; pfn++) {
 307                 /*
 308                  * Holes under sparsemem might not have no mem_map[]:
 309                  */
 310                 if (pfn_valid(pfn))
 311                         add_one_highpage_init(pfn_to_page(pfn), pfn, bad_ppro);
 312         }
 313         totalram_pages += totalhigh_pages;
 314 }
 315 #endif /* !CONFIG_NUMA */
 316
 317 #else
 318 # define kmap_init()                            do { } while (0)
 319 # define permanent_kmaps_init(pgd_base)         do { } while (0)
 320 # define set_highmem_pages_init(bad_ppro)       do { } while (0)
 321 #endif /* CONFIG_HIGHMEM */
 322
 323 pteval_t __PAGE_KERNEL = _PAGE_KERNEL;
 324 EXPORT_SYMBOL(__PAGE_KERNEL);
 325
 326 pteval_t __PAGE_KERNEL_EXEC = _PAGE_KERNEL_EXEC;
 327
 328 void __init native_pagetable_setup_start(pgd_t *base)
 329 {
 330         unsigned long pfn, va;
 331         pgd_t *pgd;
 332         pud_t *pud;
 333         pmd_t *pmd;
 334         pte_t *pte;
 335
 336         /*
 337          * Remove any mappings which extend past the end of physical
 338          * memory from the boot time page table:
 339          */
 340         for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
 341                 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
 342                 pgd = base + pgd_index(va);
 343                 if (!pgd_present(*pgd))
 344                         break;
 345
 346                 pud = pud_offset(pgd, va);
 347                 pmd = pmd_offset(pud, va);
 348                 if (!pmd_present(*pmd))
 349                         break;
 350
 351                 pte = pte_offset_kernel(pmd, va);
 352                 if (!pte_present(*pte))
 353                         break;
 354
 355                 pte_clear(NULL, va, pte);
 356         }
 357         paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
 358 }
 359
 360 void __init native_pagetable_setup_done(pgd_t *base)
 361 {
 362 }
 363
 364 /*
 365  * Build a proper pagetable for the kernel mappings.  Up until this
 366  * point, we've been running on some set of pagetables constructed by
 367  * the boot process.
 368  *
 369  * If we're booting on native hardware, this will be a pagetable
 370  * constructed in arch/x86/kernel/head_32.S.  The root of the
 371  * pagetable will be swapper_pg_dir.
 372  *
 373  * If we're booting paravirtualized under a hypervisor, then there are
 374  * more options: we may already be running PAE, and the pagetable may
 375  * or may not be based in swapper_pg_dir.  In any case,
 376  * paravirt_pagetable_setup_start() will set up swapper_pg_dir
 377  * appropriately for the rest of the initialization to work.
 378  *
 379  * In general, pagetable_init() assumes that the pagetable may already
 380  * be partially populated, and so it avoids stomping on any existing
 381  * mappings.
 382  */
 383 static void __init pagetable_init(void)
 384 {
 385         pgd_t *pgd_base = swapper_pg_dir;
 386         unsigned long vaddr, end;
 387
 388         paravirt_pagetable_setup_start(pgd_base);
 389
 390         /* Enable PSE if available */
 391         if (cpu_has_pse)
 392                 set_in_cr4(X86_CR4_PSE);
 393
 394         /* Enable PGE if available */
 395         if (cpu_has_pge) {
 396                 set_in_cr4(X86_CR4_PGE);
 397                 __PAGE_KERNEL |= _PAGE_GLOBAL;
 398                 __PAGE_KERNEL_EXEC |= _PAGE_GLOBAL;
 399         }
 400
 401         kernel_physical_mapping_init(pgd_base);
 402         remap_numa_kva();
 403
 404         /*
 405          * Fixed mappings, only the page table structure has to be
 406          * created - mappings will be set by set_fixmap():
 407          */
 408         early_ioremap_clear();
 409         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 410         end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
 411         page_table_range_init(vaddr, end, pgd_base);
 412         early_ioremap_reset();
 413
 414         permanent_kmaps_init(pgd_base);
 415
 416         paravirt_pagetable_setup_done(pgd_base);
 417 }
 418
 419 #ifdef CONFIG_ACPI_SLEEP
 420 /*
 421  * ACPI suspend needs this for resume, because things like the intel-agp
 422  * driver might have split up a kernel 4MB mapping.
 423  */
 424 char swsusp_pg_dir[PAGE_SIZE]
 425         __attribute__ ((aligned(PAGE_SIZE)));
 426
 427 static inline void save_pg_dir(void)
 428 {
 429         memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE);
 430 }
 431 #else /* !CONFIG_ACPI_SLEEP */
 432 static inline void save_pg_dir(void)
 433 {
 434 }
 435 #endif /* !CONFIG_ACPI_SLEEP */
 436
 437 void zap_low_mappings(void)
 438 {
 439         int i;
 440
 441         /*
 442          * Zap initial low-memory mappings.
 443          *
 444          * Note that "pgd_clear()" doesn't do it for
 445          * us, because pgd_clear() is a no-op on i386.
 446          */
 447         for (i = 0; i < KERNEL_PGD_BOUNDARY; i++) {
 448 #ifdef CONFIG_X86_PAE
 449                 set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page)));
 450 #else
 451                 set_pgd(swapper_pg_dir+i, __pgd(0));
 452 #endif
 453         }
 454         flush_tlb_all();
 455 }
 456
 457 int nx_enabled;
 458
 459 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_NX;
 460 EXPORT_SYMBOL_GPL(__supported_pte_mask);
 461
 462 #ifdef CONFIG_X86_PAE
 463
 464 static int disable_nx __initdata;
 465
 466 /*
 467  * noexec = on|off
 468  *
 469  * Control non executable mappings.
 470  *
 471  * on      Enable
 472  * off     Disable
 473  */
 474 static int __init noexec_setup(char *str)
 475 {
 476         if (!str || !strcmp(str, "on")) {
 477                 if (cpu_has_nx) {
 478                         __supported_pte_mask |= _PAGE_NX;
 479                         disable_nx = 0;
 480                 }
 481         } else {
 482                 if (!strcmp(str, "off")) {
 483                         disable_nx = 1;
 484                         __supported_pte_mask &= ~_PAGE_NX;
 485                 } else {
 486                         return -EINVAL;
 487                 }
 488         }
 489
 490         return 0;
 491 }
 492 early_param("noexec", noexec_setup);
 493
 494 static void __init set_nx(void)
 495 {
 496         unsigned int v[4], l, h;
 497
 498         if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) {
 499                 cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]);
 500
 501                 if ((v[3] & (1 << 20)) && !disable_nx) {
 502                         rdmsr(MSR_EFER, l, h);
 503                         l |= EFER_NX;
 504                         wrmsr(MSR_EFER, l, h);
 505                         nx_enabled = 1;
 506                         __supported_pte_mask |= _PAGE_NX;
 507                 }
 508         }
 509 }
 510 #endif
 511
 512 /*
 513  * paging_init() sets up the page tables - note that the first 8MB are
 514  * already mapped by head.S.
 515  *
 516  * This routines also unmaps the page at virtual kernel address 0, so
 517  * that we can trap those pesky NULL-reference errors in the kernel.
 518  */
 519 void __init paging_init(void)
 520 {
 521 #ifdef CONFIG_X86_PAE
 522         set_nx();
 523         if (nx_enabled)
 524                 printk(KERN_INFO "NX (Execute Disable) protection: active\n");
 525 #endif
 526         pagetable_init();
 527
 528         load_cr3(swapper_pg_dir);
 529
 530         __flush_tlb_all();
 531
 532         kmap_init();
 533 }
 534
 535 /*
 536  * Test if the WP bit works in supervisor mode. It isn't supported on 386's
 537  * and also on some strange 486's. All 586+'s are OK. This used to involve
 538  * black magic jumps to work around some nasty CPU bugs, but fortunately the
 539  * switch to using exceptions got rid of all that.
 540  */
 541 static void __init test_wp_bit(void)
 542 {
 543         printk(KERN_INFO
 544   "Checking if this processor honours the WP bit even in supervisor mode...");
 545
 546         /* Any page-aligned address will do, the test is non-destructive */
 547         __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY);
 548         boot_cpu_data.wp_works_ok = do_test_wp_bit();
 549         clear_fixmap(FIX_WP_TEST);
 550
 551         if (!boot_cpu_data.wp_works_ok) {
 552                 printk(KERN_CONT "No.\n");
 553 #ifdef CONFIG_X86_WP_WORKS_OK
 554                 panic(
 555   "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
 556 #endif
 557         } else {
 558                 printk(KERN_CONT "Ok.\n");
 559         }
 560 }
 561
 562 static struct kcore_list kcore_mem, kcore_vmalloc;
 563
 564 void __init mem_init(void)
 565 {
 566         int codesize, reservedpages, datasize, initsize;
 567         int tmp, bad_ppro;
 568
 569 #ifdef CONFIG_FLATMEM
 570         BUG_ON(!mem_map);
 571 #endif
 572         bad_ppro = ppro_with_ram_bug();
 573
 574 #ifdef CONFIG_HIGHMEM
 575         /* check that fixmap and pkmap do not overlap */
 576         if (PKMAP_BASE + LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
 577                 printk(KERN_ERR
 578                         "fixmap and kmap areas overlap - this will crash\n");
 579                 printk(KERN_ERR "pkstart: %lxh pkend: %lxh fixstart %lxh\n",
 580                                 PKMAP_BASE, PKMAP_BASE + LAST_PKMAP*PAGE_SIZE,
 581                                 FIXADDR_START);
 582                 BUG();
 583         }
 584 #endif
 585         /* this will put all low memory onto the freelists */
 586         totalram_pages += free_all_bootmem();
 587
 588         reservedpages = 0;
 589         for (tmp = 0; tmp < max_low_pfn; tmp++)
 590                 /*
 591                  * Only count reserved RAM pages:
 592                  */
 593                 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp)))
 594                         reservedpages++;
 595
 596         set_highmem_pages_init(bad_ppro);
 597
 598         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 599         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 600         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 601
 602         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 603         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 604                    VMALLOC_END-VMALLOC_START);
 605
 606         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
 607                         "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
 608                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 609                 num_physpages << (PAGE_SHIFT-10),
 610                 codesize >> 10,
 611                 reservedpages << (PAGE_SHIFT-10),
 612                 datasize >> 10,
 613                 initsize >> 10,
 614                 (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10))
 615                );
 616
 617 #if 1 /* double-sanity-check paranoia */
 618         printk(KERN_INFO "virtual kernel memory layout:\n"
 619                 "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 620 #ifdef CONFIG_HIGHMEM
 621                 "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 622 #endif
 623                 "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 624                 "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 625                 "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 626                 "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 627                 "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
 628                 FIXADDR_START, FIXADDR_TOP,
 629                 (FIXADDR_TOP - FIXADDR_START) >> 10,
 630
 631 #ifdef CONFIG_HIGHMEM
 632                 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
 633                 (LAST_PKMAP*PAGE_SIZE) >> 10,
 634 #endif
 635
 636                 VMALLOC_START, VMALLOC_END,
 637                 (VMALLOC_END - VMALLOC_START) >> 20,
 638
 639                 (unsigned long)__va(0), (unsigned long)high_memory,
 640                 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
 641
 642                 (unsigned long)&__init_begin, (unsigned long)&__init_end,
 643                 ((unsigned long)&__init_end -
 644                  (unsigned long)&__init_begin) >> 10,
 645
 646                 (unsigned long)&_etext, (unsigned long)&_edata,
 647                 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
 648
 649                 (unsigned long)&_text, (unsigned long)&_etext,
 650                 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
 651
 652 #ifdef CONFIG_HIGHMEM
 653         BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE        > FIXADDR_START);
 654         BUG_ON(VMALLOC_END                              > PKMAP_BASE);
 655 #endif
 656         BUG_ON(VMALLOC_START                            > VMALLOC_END);
 657         BUG_ON((unsigned long)high_memory               > VMALLOC_START);
 658 #endif /* double-sanity-check paranoia */
 659
 660         if (boot_cpu_data.wp_works_ok < 0)
 661                 test_wp_bit();
 662
 663         cpa_init();
 664         save_pg_dir();
 665         zap_low_mappings();
 666 }
 667
 668 #ifdef CONFIG_MEMORY_HOTPLUG
 669 int arch_add_memory(int nid, u64 start, u64 size)
 670 {
 671         struct pglist_data *pgdata = NODE_DATA(nid);
 672         struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM;
 673         unsigned long start_pfn = start >> PAGE_SHIFT;
 674         unsigned long nr_pages = size >> PAGE_SHIFT;
 675
 676         return __add_pages(zone, start_pfn, nr_pages);
 677 }
 678 #endif
 679
 680 /*
 681  * This function cannot be __init, since exceptions don't work in that
 682  * section.  Put this after the callers, so that it cannot be inlined.
 683  */
 684 static noinline int do_test_wp_bit(void)
 685 {
 686         char tmp_reg;
 687         int flag;
 688
 689         __asm__ __volatile__(
 690                 "       movb %0, %1     \n"
 691                 "1:     movb %1, %0     \n"
 692                 "       xorl %2, %2     \n"
 693                 "2:                     \n"
 694                 _ASM_EXTABLE(1b,2b)
 695                 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
 696                  "=q" (tmp_reg),
 697                  "=r" (flag)
 698                 :"2" (1)
 699                 :"memory");
 700
 701         return flag;
 702 }
 703
 704 #ifdef CONFIG_DEBUG_RODATA
 705 const int rodata_test_data = 0xC3;
 706 EXPORT_SYMBOL_GPL(rodata_test_data);
 707
 708 void mark_rodata_ro(void)
 709 {
 710         unsigned long start = PFN_ALIGN(_text);
 711         unsigned long size = PFN_ALIGN(_etext) - start;
 712
 713         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
 714         printk(KERN_INFO "Write protecting the kernel text: %luk\n",
 715                 size >> 10);
 716
 717 #ifdef CONFIG_CPA_DEBUG
 718         printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
 719                 start, start+size);
 720         set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
 721
 722         printk(KERN_INFO "Testing CPA: write protecting again\n");
 723         set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
 724 #endif
 725         start += size;
 726         size = (unsigned long)__end_rodata - start;
 727         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
 728         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
 729                 size >> 10);
 730         rodata_test();
 731
 732 #ifdef CONFIG_CPA_DEBUG
 733         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
 734         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
 735
 736         printk(KERN_INFO "Testing CPA: write protecting again\n");
 737         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
 738 #endif
 739 }
 740 #endif
 741
 742 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 743 {
 744 #ifdef CONFIG_DEBUG_PAGEALLOC
 745         /*
 746          * If debugging page accesses then do not free this memory but
 747          * mark them not present - any buggy init-section access will
 748          * create a kernel page fault:
 749          */
 750         printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
 751                 begin, PAGE_ALIGN(end));
 752         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
 753 #else
 754         unsigned long addr;
 755
 756         /*
 757          * We just marked the kernel text read only above, now that
 758          * we are going to free part of that, we need to make that
 759          * writeable first.
 760          */
 761         set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
 762
 763         for (addr = begin; addr < end; addr += PAGE_SIZE) {
 764                 ClearPageReserved(virt_to_page(addr));
 765                 init_page_count(virt_to_page(addr));
 766                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
 767                 free_page(addr);
 768                 totalram_pages++;
 769         }
 770         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
 771 #endif
 772 }
 773
 774 void free_initmem(void)
 775 {
 776         free_init_pages("unused kernel memory",
 777                         (unsigned long)(&__init_begin),
 778                         (unsigned long)(&__init_end));
 779 }
 780
 781 #ifdef CONFIG_BLK_DEV_INITRD
 782 void free_initrd_mem(unsigned long start, unsigned long end)
 783 {
 784         free_init_pages("initrd memory", start, end);
 785 }
 786 #endif