arch/i386/mm/init-xen.c

   1 /*
   2  *  linux/arch/i386/mm/init.c
   3  *
   4  *  Copyright (C) 1995  Linus Torvalds
   5  *
   6  *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
   7  */
   8
   9 #include <linux/config.h>
  10 #include <linux/module.h>
  11 #include <linux/signal.h>
  12 #include <linux/sched.h>
  13 #include <linux/kernel.h>
  14 #include <linux/errno.h>
  15 #include <linux/string.h>
  16 #include <linux/types.h>
  17 #include <linux/ptrace.h>
  18 #include <linux/mman.h>
  19 #include <linux/mm.h>
  20 #include <linux/hugetlb.h>
  21 #include <linux/swap.h>
  22 #include <linux/smp.h>
  23 #include <linux/init.h>
  24 #include <linux/highmem.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/bootmem.h>
  27 #include <linux/slab.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/efi.h>
  30 #include <linux/memory_hotplug.h>
  31 #include <linux/initrd.h>
  32 #include <linux/dma-mapping.h>
  33 #include <linux/scatterlist.h>
  34
  35 #include <asm/processor.h>
  36 #include <asm/system.h>
  37 #include <asm/uaccess.h>
  38 #include <asm/pgtable.h>
  39 #include <asm/dma.h>
  40 #include <asm/fixmap.h>
  41 #include <asm/e820.h>
  42 #include <asm/apic.h>
  43 #include <asm/tlb.h>
  44 #include <asm/tlbflush.h>
  45 #include <asm/sections.h>
  46 #include <asm/hypervisor.h>
  47 #include <asm/swiotlb.h>
  48
  49 extern unsigned long *contiguous_bitmap;
  50
  51 unsigned int __VMALLOC_RESERVE = 128 << 20;
  52
  53 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  54 unsigned long highstart_pfn, highend_pfn;
  55
  56 static int noinline do_test_wp_bit(void);
  57
  58 /*
  59  * Creates a middle page table and puts a pointer to it in the
  60  * given global directory entry. This only returns the gd entry
  61  * in non-PAE compilation mode, since the middle layer is folded.
  62  */
  63 static pmd_t * __init one_md_table_init(pgd_t *pgd)
  64 {
  65         pud_t *pud;
  66         pmd_t *pmd_table;
  67
  68 #ifdef CONFIG_X86_PAE
  69         pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
  70         make_lowmem_page_readonly(pmd_table, XENFEAT_writable_page_tables);
  71         set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
  72         pud = pud_offset(pgd, 0);
  73         if (pmd_table != pmd_offset(pud, 0))
  74                 BUG();
  75 #else
  76         pud = pud_offset(pgd, 0);
  77         pmd_table = pmd_offset(pud, 0);
  78 #endif
  79
  80         return pmd_table;
  81 }
  82
  83 /*
  84  * Create a page table and place a pointer to it in a middle page
  85  * directory entry.
  86  */
  87 static pte_t * __init one_page_table_init(pmd_t *pmd)
  88 {
  89         if (pmd_none(*pmd)) {
  90                 pte_t *page_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
  91                 make_lowmem_page_readonly(page_table,
  92                                           XENFEAT_writable_page_tables);
  93                 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
  94                 if (page_table != pte_offset_kernel(pmd, 0))
  95                         BUG();
  96
  97                 return page_table;
  98         }
  99
 100         return pte_offset_kernel(pmd, 0);
 101 }
 102
 103 /*
 104  * This function initializes a certain range of kernel virtual memory
 105  * with new bootmem page tables, everywhere page tables are missing in
 106  * the given range.
 107  */
 108
 109 /*
 110  * NOTE: The pagetables are allocated contiguous on the physical space
 111  * so we can cache the place of the first one and move around without
 112  * checking the pgd every time.
 113  */
 114 static void __init page_table_range_init (unsigned long start, unsigned long end, pgd_t *pgd_base)
 115 {
 116         pgd_t *pgd;
 117         pud_t *pud;
 118         pmd_t *pmd;
 119         int pgd_idx, pmd_idx;
 120         unsigned long vaddr;
 121
 122         vaddr = start;
 123         pgd_idx = pgd_index(vaddr);
 124         pmd_idx = pmd_index(vaddr);
 125         pgd = pgd_base + pgd_idx;
 126
 127         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
 128                 if (pgd_none(*pgd))
 129                         one_md_table_init(pgd);
 130                 pud = pud_offset(pgd, vaddr);
 131                 pmd = pmd_offset(pud, vaddr);
 132                 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); pmd++, pmd_idx++) {
 133                         if (vaddr < HYPERVISOR_VIRT_START && pmd_none(*pmd))
 134                                 one_page_table_init(pmd);
 135
 136                         vaddr += PMD_SIZE;
 137                 }
 138                 pmd_idx = 0;
 139         }
 140 }
 141
 142 static inline int is_kernel_text(unsigned long addr)
 143 {
 144         if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end)
 145                 return 1;
 146         return 0;
 147 }
 148
 149 /*
 150  * This maps the physical memory to kernel virtual address space, a total
 151  * of max_low_pfn pages, by creating page tables starting from address
 152  * PAGE_OFFSET.
 153  */
 154 static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
 155 {
 156         unsigned long pfn;
 157         pgd_t *pgd;
 158         pmd_t *pmd;
 159         pte_t *pte;
 160         int pgd_idx, pmd_idx, pte_ofs;
 161
 162         unsigned long max_ram_pfn = xen_start_info->nr_pages;
 163         if (max_ram_pfn > max_low_pfn)
 164                 max_ram_pfn = max_low_pfn;
 165
 166         pgd_idx = pgd_index(PAGE_OFFSET);
 167         pgd = pgd_base + pgd_idx;
 168         pfn = 0;
 169         pmd_idx = pmd_index(PAGE_OFFSET);
 170         pte_ofs = pte_index(PAGE_OFFSET);
 171
 172         for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
 173 #ifdef CONFIG_XEN
 174                 /*
 175                  * Native linux hasn't PAE-paging enabled yet at this
 176                  * point.  When running as xen domain we are in PAE
 177                  * mode already, thus we can't simply hook a empty
 178                  * pmd.  That would kill the mappings we are currently
 179                  * using ...
 180                  */
 181                 pmd = pmd_offset(pud_offset(pgd, PAGE_OFFSET), PAGE_OFFSET);
 182 #else
 183                 pmd = one_md_table_init(pgd);
 184 #endif
 185                 if (pfn >= max_low_pfn)
 186                         continue;
 187                 pmd += pmd_idx;
 188                 for (; pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn; pmd++, pmd_idx++) {
 189                         unsigned int address = pfn * PAGE_SIZE + PAGE_OFFSET;
 190                         if (address >= HYPERVISOR_VIRT_START)
 191                                 continue;
 192
 193                         /* Map with big pages if possible, otherwise create normal page tables. */
 194                         if (cpu_has_pse) {
 195                                 unsigned int address2 = (pfn + PTRS_PER_PTE - 1) * PAGE_SIZE + PAGE_OFFSET + PAGE_SIZE-1;
 196
 197                                 if (is_kernel_text(address) || is_kernel_text(address2))
 198                                         set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC));
 199                                 else
 200                                         set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE));
 201                                 pfn += PTRS_PER_PTE;
 202                         } else {
 203                                 pte = one_page_table_init(pmd);
 204
 205                                 pte += pte_ofs;
 206                                 for (; pte_ofs < PTRS_PER_PTE && pfn < max_low_pfn; pte++, pfn++, pte_ofs++) {
 207                                                 /* XEN: Only map initial RAM allocation. */
 208                                                 if ((pfn >= max_ram_pfn) || pte_present(*pte))
 209                                                         continue;
 210                                                 if (is_kernel_text(address))
 211                                                         set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC));
 212                                                 else
 213                                                         set_pte(pte, pfn_pte(pfn, PAGE_KERNEL));
 214                                 }
 215                                 pte_ofs = 0;
 216                         }
 217                 }
 218                 pmd_idx = 0;
 219         }
 220 }
 221
 222 #ifndef CONFIG_XEN
 223
 224 static inline int page_kills_ppro(unsigned long pagenr)
 225 {
 226         if (pagenr >= 0x70000 && pagenr <= 0x7003F)
 227                 return 1;
 228         return 0;
 229 }
 230
 231 #else
 232
 233 #define page_kills_ppro(p)      0
 234
 235 #endif
 236
 237 extern int is_available_memory(efi_memory_desc_t *);
 238
 239 int page_is_ram(unsigned long pagenr)
 240 {
 241         int i;
 242         unsigned long addr, end;
 243
 244         if (efi_enabled) {
 245                 efi_memory_desc_t *md;
 246                 void *p;
 247
 248                 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 249                         md = p;
 250                         if (!is_available_memory(md))
 251                                 continue;
 252                         addr = (md->phys_addr+PAGE_SIZE-1) >> PAGE_SHIFT;
 253                         end = (md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT)) >> PAGE_SHIFT;
 254
 255                         if ((pagenr >= addr) && (pagenr < end))
 256                                 return 1;
 257                 }
 258                 return 0;
 259         }
 260
 261         for (i = 0; i < e820.nr_map; i++) {
 262
 263                 if (e820.map[i].type != E820_RAM)       /* not usable memory */
 264                         continue;
 265                 /*
 266                  *      !!!FIXME!!! Some BIOSen report areas as RAM that
 267                  *      are not. Notably the 640->1Mb area. We need a sanity
 268                  *      check here.
 269                  */
 270                 addr = (e820.map[i].addr+PAGE_SIZE-1) >> PAGE_SHIFT;
 271                 end = (e820.map[i].addr+e820.map[i].size) >> PAGE_SHIFT;
 272                 if  ((pagenr >= addr) && (pagenr < end))
 273                         return 1;
 274         }
 275         return 0;
 276 }
 277
 278 int devmem_is_allowed(unsigned long pagenr)
 279 {
 280    if (pagenr <= 256)
 281        return 1;
 282    if (!page_is_ram(pagenr))
 283        return 1;
 284    return 0;
 285 }
 286
 287 EXPORT_SYMBOL_GPL(page_is_ram);
 288
 289 #ifdef CONFIG_HIGHMEM
 290 pte_t *kmap_pte;
 291 pgprot_t kmap_prot;
 292
 293 #define kmap_get_fixmap_pte(vaddr)                                      \
 294         pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), vaddr), (vaddr)), (vaddr))
 295
 296 static void __init kmap_init(void)
 297 {
 298         unsigned long kmap_vstart;
 299
 300         /* cache the first kmap pte */
 301         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
 302         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
 303
 304         kmap_prot = PAGE_KERNEL;
 305 }
 306
 307 static void __init permanent_kmaps_init(pgd_t *pgd_base)
 308 {
 309         pgd_t *pgd;
 310         pud_t *pud;
 311         pmd_t *pmd;
 312         pte_t *pte;
 313         unsigned long vaddr;
 314
 315         vaddr = PKMAP_BASE;
 316         page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
 317
 318         pgd = swapper_pg_dir + pgd_index(vaddr);
 319         pud = pud_offset(pgd, vaddr);
 320         pmd = pmd_offset(pud, vaddr);
 321         pte = pte_offset_kernel(pmd, vaddr);
 322         pkmap_page_table = pte;
 323 }
 324
 325 static void __meminit free_new_highpage(struct page *page, int pfn)
 326 {
 327         init_page_count(page);
 328         if (pfn < xen_start_info->nr_pages)
 329                 __free_page(page);
 330         totalhigh_pages++;
 331 }
 332
 333 void __init add_one_highpage_init(struct page *page, int pfn, int bad_ppro)
 334 {
 335         if (page_is_ram(pfn) && !(bad_ppro && page_kills_ppro(pfn))) {
 336                 ClearPageReserved(page);
 337                 free_new_highpage(page, pfn);
 338         } else
 339                 SetPageReserved(page);
 340 }
 341
 342 static int add_one_highpage_hotplug(struct page *page, unsigned long pfn)
 343 {
 344         free_new_highpage(page, pfn);
 345         totalram_pages++;
 346 #ifdef CONFIG_FLATMEM
 347         max_mapnr = max(pfn, max_mapnr);
 348 #endif
 349         num_physpages++;
 350         return 0;
 351 }
 352
 353 /*
 354  * Not currently handling the NUMA case.
 355  * Assuming single node and all memory that
 356  * has been added dynamically that would be
 357  * onlined here is in HIGHMEM
 358  */
 359 void online_page(struct page *page)
 360 {
 361         ClearPageReserved(page);
 362         add_one_highpage_hotplug(page, page_to_pfn(page));
 363 }
 364
 365
 366 #ifdef CONFIG_NUMA
 367 extern void set_highmem_pages_init(int);
 368 #else
 369 static void __init set_highmem_pages_init(int bad_ppro)
 370 {
 371         int pfn;
 372         for (pfn = highstart_pfn; pfn < highend_pfn; pfn++)
 373                 add_one_highpage_init(pfn_to_page(pfn), pfn, bad_ppro);
 374         totalram_pages += totalhigh_pages;
 375 }
 376 #endif /* CONFIG_FLATMEM */
 377
 378 #else
 379 #define kmap_init() do { } while (0)
 380 #define permanent_kmaps_init(pgd_base) do { } while (0)
 381 #define set_highmem_pages_init(bad_ppro) do { } while (0)
 382 #endif /* CONFIG_HIGHMEM */
 383
 384 unsigned long long __PAGE_KERNEL = _PAGE_KERNEL;
 385 EXPORT_SYMBOL(__PAGE_KERNEL);
 386 unsigned long long __PAGE_KERNEL_EXEC = _PAGE_KERNEL_EXEC;
 387
 388 #ifdef CONFIG_NUMA
 389 extern void __init remap_numa_kva(void);
 390 #else
 391 #define remap_numa_kva() do {} while (0)
 392 #endif
 393
 394 pgd_t *swapper_pg_dir;
 395
 396 static void __init pagetable_init (void)
 397 {
 398         unsigned long vaddr;
 399         pgd_t *pgd_base = (pgd_t *)xen_start_info->pt_base;
 400
 401         swapper_pg_dir = pgd_base;
 402         init_mm.pgd    = pgd_base;
 403
 404         /* Enable PSE if available */
 405         if (cpu_has_pse) {
 406                 set_in_cr4(X86_CR4_PSE);
 407         }
 408
 409         /* Enable PGE if available */
 410         if (cpu_has_pge) {
 411                 set_in_cr4(X86_CR4_PGE);
 412                 __PAGE_KERNEL |= _PAGE_GLOBAL;
 413                 __PAGE_KERNEL_EXEC |= _PAGE_GLOBAL;
 414         }
 415
 416         kernel_physical_mapping_init(pgd_base);
 417         remap_numa_kva();
 418
 419         /*
 420          * Fixed mappings, only the page table structure has to be
 421          * created - mappings will be set by set_fixmap():
 422          */
 423         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 424         page_table_range_init(vaddr, 0, pgd_base);
 425
 426         permanent_kmaps_init(pgd_base);
 427 }
 428
 429 #ifdef CONFIG_SOFTWARE_SUSPEND
 430 /*
 431  * Swap suspend & friends need this for resume because things like the intel-agp
 432  * driver might have split up a kernel 4MB mapping.
 433  */
 434 char __nosavedata swsusp_pg_dir[PAGE_SIZE]
 435         __attribute__ ((aligned (PAGE_SIZE)));
 436
 437 static inline void save_pg_dir(void)
 438 {
 439         memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE);
 440 }
 441 #else
 442 static inline void save_pg_dir(void)
 443 {
 444 }
 445 #endif
 446
 447 void zap_low_mappings (void)
 448 {
 449         int i;
 450
 451         save_pg_dir();
 452
 453         /*
 454          * Zap initial low-memory mappings.
 455          *
 456          * Note that "pgd_clear()" doesn't do it for
 457          * us, because pgd_clear() is a no-op on i386.
 458          */
 459         for (i = 0; i < USER_PTRS_PER_PGD; i++)
 460 #if defined(CONFIG_X86_PAE) && !defined(CONFIG_XEN)
 461                 set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page)));
 462 #else
 463                 set_pgd(swapper_pg_dir+i, __pgd(0));
 464 #endif
 465         flush_tlb_all();
 466 }
 467
 468 static int disable_nx __initdata = 0;
 469 u64 __supported_pte_mask __read_mostly = ~_PAGE_NX;
 470 EXPORT_SYMBOL(__supported_pte_mask);
 471
 472 /*
 473  * noexec = on|off
 474  *
 475  * Control non executable mappings.
 476  *
 477  * on      Enable
 478  * off     Disable (disables exec-shield too)
 479  */
 480 void __init noexec_setup(const char *str)
 481 {
 482         if (!strncmp(str, "on",2) && cpu_has_nx) {
 483                 __supported_pte_mask |= _PAGE_NX;
 484                 disable_nx = 0;
 485         } else if (!strncmp(str,"off",3)) {
 486                 disable_nx = 1;
 487                 __supported_pte_mask &= ~_PAGE_NX;
 488                 exec_shield = 0;
 489         }
 490 }
 491
 492 int nx_enabled = 0;
 493 #ifdef CONFIG_X86_PAE
 494
 495 static void __init set_nx(void)
 496 {
 497         unsigned int v[4], l, h;
 498
 499         if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) {
 500                 cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]);
 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
 511 /*
 512  * Enables/disables executability of a given kernel page and
 513  * returns the previous setting.
 514  */
 515 int __init set_kernel_exec(unsigned long vaddr, int enable)
 516 {
 517         pte_t *pte;
 518         int ret = 1;
 519
 520         if (!nx_enabled)
 521                 goto out;
 522
 523         pte = lookup_address(vaddr);
 524         BUG_ON(!pte);
 525
 526         if (!pte_exec_kernel(*pte))
 527                 ret = 0;
 528
 529         if (enable)
 530                 pte->pte_high &= ~(1 << (_PAGE_BIT_NX - 32));
 531         else
 532                 pte->pte_high |= 1 << (_PAGE_BIT_NX - 32);
 533         __flush_tlb_all();
 534 out:
 535         return ret;
 536 }
 537
 538 #endif
 539
 540 /*
 541  * paging_init() sets up the page tables - note that the first 8MB are
 542  * already mapped by head.S.
 543  *
 544  * This routines also unmaps the page at virtual kernel address 0, so
 545  * that we can trap those pesky NULL-reference errors in the kernel.
 546  */
 547 void __init paging_init(void)
 548 {
 549         int i;
 550
 551 #ifdef CONFIG_X86_PAE
 552         set_nx();
 553         if (nx_enabled)
 554                 printk("NX (Execute Disable) protection: active\n");
 555         else
 556 #endif
 557         if (exec_shield)
 558                 printk("Using x86 segment limits to approximate NX protection\n");
 559
 560         pagetable_init();
 561
 562 #if defined(CONFIG_X86_PAE) && !defined(CONFIG_XEN)
 563         /*
 564          * We will bail out later - printk doesn't work right now so
 565          * the user would just see a hanging kernel.
 566          * when running as xen domain we are already in PAE mode at
 567          * this point.
 568          */
 569         if (cpu_has_pae)
 570                 set_in_cr4(X86_CR4_PAE);
 571 #endif
 572         __flush_tlb_all();
 573
 574         kmap_init();
 575
 576         /* Switch to the real shared_info page, and clear the
 577          * dummy page. */
 578         set_fixmap(FIX_SHARED_INFO, xen_start_info->shared_info);
 579         HYPERVISOR_shared_info = (shared_info_t *)fix_to_virt(FIX_SHARED_INFO);
 580         memset(empty_zero_page, 0, sizeof(empty_zero_page));
 581
 582         /* Setup mapping of lower 1st MB */
 583         for (i = 0; i < NR_FIX_ISAMAPS; i++)
 584                 if (xen_start_info->flags & SIF_PRIVILEGED)
 585                         set_fixmap(FIX_ISAMAP_BEGIN - i, i * PAGE_SIZE);
 586                 else
 587                         __set_fixmap(FIX_ISAMAP_BEGIN - i,
 588                                      virt_to_machine(empty_zero_page),
 589                                      PAGE_KERNEL_RO);
 590 }
 591
 592 /*
 593  * Test if the WP bit works in supervisor mode. It isn't supported on 386's
 594  * and also on some strange 486's (NexGen etc.). All 586+'s are OK. This
 595  * used to involve black magic jumps to work around some nasty CPU bugs,
 596  * but fortunately the switch to using exceptions got rid of all that.
 597  */
 598
 599 static void __init test_wp_bit(void)
 600 {
 601         printk("Checking if this processor honours the WP bit even in supervisor mode... ");
 602
 603         /* Any page-aligned address will do, the test is non-destructive */
 604         __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY);
 605         boot_cpu_data.wp_works_ok = do_test_wp_bit();
 606         clear_fixmap(FIX_WP_TEST);
 607
 608         if (!boot_cpu_data.wp_works_ok) {
 609                 printk("No.\n");
 610 #ifdef CONFIG_X86_WP_WORKS_OK
 611                 panic("This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
 612 #endif
 613         } else {
 614                 printk("Ok.\n");
 615         }
 616 }
 617
 618 static void __init set_max_mapnr_init(void)
 619 {
 620 #ifdef CONFIG_HIGHMEM
 621         num_physpages = highend_pfn;
 622 #else
 623         num_physpages = max_low_pfn;
 624 #endif
 625 #ifdef CONFIG_FLATMEM
 626         max_mapnr = num_physpages;
 627 #endif
 628 }
 629
 630 static struct kcore_list kcore_mem, kcore_vmalloc;
 631
 632 void __init mem_init(void)
 633 {
 634         extern int ppro_with_ram_bug(void);
 635         int codesize, reservedpages, datasize, initsize;
 636         int tmp;
 637         int bad_ppro;
 638         unsigned long pfn;
 639
 640         contiguous_bitmap = alloc_bootmem_low_pages(
 641                 (max_low_pfn + 2*BITS_PER_LONG) >> 3);
 642         BUG_ON(!contiguous_bitmap);
 643         memset(contiguous_bitmap, 0, (max_low_pfn + 2*BITS_PER_LONG) >> 3);
 644
 645 #if defined(CONFIG_SWIOTLB)
 646         swiotlb_init();
 647 #endif
 648
 649 #ifdef CONFIG_FLATMEM
 650         if (!mem_map)
 651                 BUG();
 652 #endif
 653
 654         bad_ppro = ppro_with_ram_bug();
 655
 656 #ifdef CONFIG_HIGHMEM
 657         /* check that fixmap and pkmap do not overlap */
 658         if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
 659                 printk(KERN_ERR "fixmap and kmap areas overlap - this will crash\n");
 660                 printk(KERN_ERR "pkstart: %lxh pkend: %lxh fixstart %lxh\n",
 661                                 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, FIXADDR_START);
 662                 BUG();
 663         }
 664 #endif
 665
 666         set_max_mapnr_init();
 667
 668 #ifdef CONFIG_HIGHMEM
 669         high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
 670 #else
 671         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
 672 #endif
 673         printk("vmalloc area: %lx-%lx, maxmem %lx\n",
 674                VMALLOC_START,VMALLOC_END,MAXMEM);
 675         BUG_ON(VMALLOC_START > VMALLOC_END);
 676
 677         /* this will put all low memory onto the freelists */
 678         totalram_pages += free_all_bootmem();
 679         /* XEN: init and count low-mem pages outside initial allocation. */
 680         for (pfn = xen_start_info->nr_pages; pfn < max_low_pfn; pfn++) {
 681                 ClearPageReserved(&mem_map[pfn]);
 682                 init_page_count(&mem_map[pfn]);
 683                 totalram_pages++;
 684         }
 685
 686         reservedpages = 0;
 687         for (tmp = 0; tmp < max_low_pfn; tmp++)
 688                 /*
 689                  * Only count reserved RAM pages
 690                  */
 691                 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp)))
 692                         reservedpages++;
 693
 694         set_highmem_pages_init(bad_ppro);
 695
 696         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 697         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 698         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 699
 700         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 701         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 702                    VMALLOC_END-VMALLOC_START);
 703
 704         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n",
 705                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 706                 num_physpages << (PAGE_SHIFT-10),
 707                 codesize >> 10,
 708                 reservedpages << (PAGE_SHIFT-10),
 709                 datasize >> 10,
 710                 initsize >> 10,
 711                 (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10))
 712                );
 713
 714 #ifdef CONFIG_X86_PAE
 715         if (!cpu_has_pae)
 716                 panic("cannot execute a PAE-enabled kernel on a PAE-less CPU!");
 717 #endif
 718         if (boot_cpu_data.wp_works_ok < 0)
 719                 test_wp_bit();
 720
 721         /*
 722          * Subtle. SMP is doing it's boot stuff late (because it has to
 723          * fork idle threads) - but it also needs low mappings for the
 724          * protected-mode entry to work. We zap these entries only after
 725          * the WP-bit has been tested.
 726          */
 727 #ifndef CONFIG_SMP
 728         zap_low_mappings();
 729 #endif
 730
 731         set_bit(PG_pinned, &virt_to_page(init_mm.pgd)->flags);
 732 }
 733
 734 /*
 735  * this is for the non-NUMA, single node SMP system case.
 736  * Specifically, in the case of x86, we will always add
 737  * memory to the highmem for now.
 738  */
 739 #ifdef CONFIG_MEMORY_HOTPLUG
 740 #ifndef CONFIG_NEED_MULTIPLE_NODES
 741 int add_memory(u64 start, u64 size)
 742 {
 743         struct pglist_data *pgdata = &contig_page_data;
 744         struct zone *zone = pgdata->node_zones + MAX_NR_ZONES-1;
 745         unsigned long start_pfn = start >> PAGE_SHIFT;
 746         unsigned long nr_pages = size >> PAGE_SHIFT;
 747
 748         return __add_pages(zone, start_pfn, nr_pages);
 749 }
 750
 751 int remove_memory(u64 start, u64 size)
 752 {
 753         return -EINVAL;
 754 }
 755 #endif
 756 #endif
 757
 758 kmem_cache_t *pgd_cache;
 759 kmem_cache_t *pmd_cache;
 760
 761 void __init pgtable_cache_init(void)
 762 {
 763         if (PTRS_PER_PMD > 1) {
 764                 pmd_cache = kmem_cache_create("pmd",
 765                                         PTRS_PER_PMD*sizeof(pmd_t),
 766                                         PTRS_PER_PMD*sizeof(pmd_t),
 767                                         0,
 768                                         pmd_ctor,
 769                                         NULL);
 770                 if (!pmd_cache)
 771                         panic("pgtable_cache_init(): cannot create pmd cache");
 772         }
 773         pgd_cache = kmem_cache_create("pgd",
 774 #ifndef CONFIG_XEN
 775                                 PTRS_PER_PGD*sizeof(pgd_t),
 776                                 PTRS_PER_PGD*sizeof(pgd_t),
 777 #else
 778                                 PAGE_SIZE,
 779                                 PAGE_SIZE,
 780 #endif
 781                                 0,
 782                                 pgd_ctor,
 783                                 PTRS_PER_PMD == 1 ? pgd_dtor : NULL);
 784         if (!pgd_cache)
 785                 panic("pgtable_cache_init(): Cannot create pgd cache");
 786 }
 787
 788 /*
 789  * This function cannot be __init, since exceptions don't work in that
 790  * section.  Put this after the callers, so that it cannot be inlined.
 791  */
 792 static int noinline do_test_wp_bit(void)
 793 {
 794         char tmp_reg;
 795         int flag;
 796
 797         __asm__ __volatile__(
 798                 "       movb %0,%1      \n"
 799                 "1:     movb %1,%0      \n"
 800                 "       xorl %2,%2      \n"
 801                 "2:                     \n"
 802                 ".section __ex_table,\"a\"\n"
 803                 "       .align 4        \n"
 804                 "       .long 1b,2b     \n"
 805                 ".previous              \n"
 806                 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
 807                  "=q" (tmp_reg),
 808                  "=r" (flag)
 809                 :"2" (1)
 810                 :"memory");
 811
 812         return flag;
 813 }
 814
 815 #ifdef CONFIG_DEBUG_RODATA
 816
 817 extern char __start_rodata, __end_rodata;
 818 void mark_rodata_ro(void)
 819 {
 820         unsigned long addr = (unsigned long)&__start_rodata;
 821
 822         for (; addr < (unsigned long)&__end_rodata; addr += PAGE_SIZE)
 823                 change_page_attr(virt_to_page(addr), 1, PAGE_KERNEL_RO);
 824
 825         printk ("Write protecting the kernel read-only data: %luk\n",
 826                         (unsigned long)(&__end_rodata - &__start_rodata) >> 10);
 827
 828         /*
 829          * change_page_attr() requires a global_flush_tlb() call after it.
 830          * We do this after the printk so that if something went wrong in the
 831          * change, the printk gets out at least to give a better debug hint
 832          * of who is the culprit.
 833          */
 834         global_flush_tlb();
 835 }
 836 #endif
 837
 838 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 839 {
 840         unsigned long addr;
 841
 842         for (addr = begin; addr < end; addr += PAGE_SIZE) {
 843                 ClearPageReserved(virt_to_page(addr));
 844                 init_page_count(virt_to_page(addr));
 845                 memset((void *)addr, 0xcc, PAGE_SIZE);
 846                 free_page(addr);
 847                 totalram_pages++;
 848         }
 849         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 850 }
 851
 852 void free_initmem(void)
 853 {
 854         free_init_pages("unused kernel memory",
 855                         (unsigned long)(&__init_begin),
 856                         (unsigned long)(&__init_end));
 857 }
 858
 859 #ifdef CONFIG_BLK_DEV_INITRD
 860 void free_initrd_mem(unsigned long start, unsigned long end)
 861 {
 862         free_init_pages("initrd memory", start, end);
 863 }
 864 #endif
 865