linux/arch/x86/mm/init_64.c
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   1/*
   2 *  linux/arch/x86_64/mm/init.c
   3 *
   4 *  Copyright (C) 1995  Linus Torvalds
   5 *  Copyright (C) 2000  Pavel Machek <pavel@suse.cz>
   6 *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
   7 */
   8
   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/swap.h>
  19#include <linux/smp.h>
  20#include <linux/init.h>
  21#include <linux/initrd.h>
  22#include <linux/pagemap.h>
  23#include <linux/bootmem.h>
  24#include <linux/proc_fs.h>
  25#include <linux/pci.h>
  26#include <linux/pfn.h>
  27#include <linux/poison.h>
  28#include <linux/dma-mapping.h>
  29#include <linux/module.h>
  30#include <linux/memory_hotplug.h>
  31#include <linux/nmi.h>
  32
  33#include <asm/processor.h>
  34#include <asm/bios_ebda.h>
  35#include <asm/system.h>
  36#include <asm/uaccess.h>
  37#include <asm/pgtable.h>
  38#include <asm/pgalloc.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/mmu_context.h>
  45#include <asm/proto.h>
  46#include <asm/smp.h>
  47#include <asm/sections.h>
  48#include <asm/kdebug.h>
  49#include <asm/numa.h>
  50#include <asm/cacheflush.h>
  51
  52/*
  53 * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
  54 * The direct mapping extends to max_pfn_mapped, so that we can directly access
  55 * apertures, ACPI and other tables without having to play with fixmaps.
  56 */
  57unsigned long max_low_pfn_mapped;
  58unsigned long max_pfn_mapped;
  59
  60static unsigned long dma_reserve __initdata;
  61
  62DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  63
  64int direct_gbpages
  65#ifdef CONFIG_DIRECT_GBPAGES
  66                                = 1
  67#endif
  68;
  69
  70static int __init parse_direct_gbpages_off(char *arg)
  71{
  72        direct_gbpages = 0;
  73        return 0;
  74}
  75early_param("nogbpages", parse_direct_gbpages_off);
  76
  77static int __init parse_direct_gbpages_on(char *arg)
  78{
  79        direct_gbpages = 1;
  80        return 0;
  81}
  82early_param("gbpages", parse_direct_gbpages_on);
  83
  84/*
  85 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  86 * physical space so we can cache the place of the first one and move
  87 * around without checking the pgd every time.
  88 */
  89
  90int after_bootmem;
  91
  92pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
  93EXPORT_SYMBOL_GPL(__supported_pte_mask);
  94
  95static int do_not_nx __cpuinitdata;
  96
  97/*
  98 * noexec=on|off
  99 * Control non-executable mappings for 64-bit processes.
 100 *
 101 * on   Enable (default)
 102 * off  Disable
 103 */
 104static int __init nonx_setup(char *str)
 105{
 106        if (!str)
 107                return -EINVAL;
 108        if (!strncmp(str, "on", 2)) {
 109                __supported_pte_mask |= _PAGE_NX;
 110                do_not_nx = 0;
 111        } else if (!strncmp(str, "off", 3)) {
 112                do_not_nx = 1;
 113                __supported_pte_mask &= ~_PAGE_NX;
 114        }
 115        return 0;
 116}
 117early_param("noexec", nonx_setup);
 118
 119void __cpuinit check_efer(void)
 120{
 121        unsigned long efer;
 122
 123        rdmsrl(MSR_EFER, efer);
 124        if (!(efer & EFER_NX) || do_not_nx)
 125                __supported_pte_mask &= ~_PAGE_NX;
 126}
 127
 128int force_personality32;
 129
 130/*
 131 * noexec32=on|off
 132 * Control non executable heap for 32bit processes.
 133 * To control the stack too use noexec=off
 134 *
 135 * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
 136 * off  PROT_READ implies PROT_EXEC
 137 */
 138static int __init nonx32_setup(char *str)
 139{
 140        if (!strcmp(str, "on"))
 141                force_personality32 &= ~READ_IMPLIES_EXEC;
 142        else if (!strcmp(str, "off"))
 143                force_personality32 |= READ_IMPLIES_EXEC;
 144        return 1;
 145}
 146__setup("noexec32=", nonx32_setup);
 147
 148/*
 149 * NOTE: This function is marked __ref because it calls __init function
 150 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 151 */
 152static __ref void *spp_getpage(void)
 153{
 154        void *ptr;
 155
 156        if (after_bootmem)
 157                ptr = (void *) get_zeroed_page(GFP_ATOMIC);
 158        else
 159                ptr = alloc_bootmem_pages(PAGE_SIZE);
 160
 161        if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 162                panic("set_pte_phys: cannot allocate page data %s\n",
 163                        after_bootmem ? "after bootmem" : "");
 164        }
 165
 166        pr_debug("spp_getpage %p\n", ptr);
 167
 168        return ptr;
 169}
 170
 171void
 172set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 173{
 174        pud_t *pud;
 175        pmd_t *pmd;
 176        pte_t *pte;
 177
 178        pud = pud_page + pud_index(vaddr);
 179        if (pud_none(*pud)) {
 180                pmd = (pmd_t *) spp_getpage();
 181                pud_populate(&init_mm, pud, pmd);
 182                if (pmd != pmd_offset(pud, 0)) {
 183                        printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 184                                pmd, pmd_offset(pud, 0));
 185                        return;
 186                }
 187        }
 188        pmd = pmd_offset(pud, vaddr);
 189        if (pmd_none(*pmd)) {
 190                pte = (pte_t *) spp_getpage();
 191                pmd_populate_kernel(&init_mm, pmd, pte);
 192                if (pte != pte_offset_kernel(pmd, 0)) {
 193                        printk(KERN_ERR "PAGETABLE BUG #02!\n");
 194                        return;
 195                }
 196        }
 197
 198        pte = pte_offset_kernel(pmd, vaddr);
 199        set_pte(pte, new_pte);
 200
 201        /*
 202         * It's enough to flush this one mapping.
 203         * (PGE mappings get flushed as well)
 204         */
 205        __flush_tlb_one(vaddr);
 206}
 207
 208void
 209set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 210{
 211        pgd_t *pgd;
 212        pud_t *pud_page;
 213
 214        pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 215
 216        pgd = pgd_offset_k(vaddr);
 217        if (pgd_none(*pgd)) {
 218                printk(KERN_ERR
 219                        "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 220                return;
 221        }
 222        pud_page = (pud_t*)pgd_page_vaddr(*pgd);
 223        set_pte_vaddr_pud(pud_page, vaddr, pteval);
 224}
 225
 226/*
 227 * Create large page table mappings for a range of physical addresses.
 228 */
 229static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 230                                                pgprot_t prot)
 231{
 232        pgd_t *pgd;
 233        pud_t *pud;
 234        pmd_t *pmd;
 235
 236        BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 237        for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 238                pgd = pgd_offset_k((unsigned long)__va(phys));
 239                if (pgd_none(*pgd)) {
 240                        pud = (pud_t *) spp_getpage();
 241                        set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
 242                                                _PAGE_USER));
 243                }
 244                pud = pud_offset(pgd, (unsigned long)__va(phys));
 245                if (pud_none(*pud)) {
 246                        pmd = (pmd_t *) spp_getpage();
 247                        set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 248                                                _PAGE_USER));
 249                }
 250                pmd = pmd_offset(pud, phys);
 251                BUG_ON(!pmd_none(*pmd));
 252                set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 253        }
 254}
 255
 256void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 257{
 258        __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
 259}
 260
 261void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 262{
 263        __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
 264}
 265
 266/*
 267 * The head.S code sets up the kernel high mapping:
 268 *
 269 *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 270 *
 271 * phys_addr holds the negative offset to the kernel, which is added
 272 * to the compile time generated pmds. This results in invalid pmds up
 273 * to the point where we hit the physaddr 0 mapping.
 274 *
 275 * We limit the mappings to the region from _text to _end.  _end is
 276 * rounded up to the 2MB boundary. This catches the invalid pmds as
 277 * well, as they are located before _text:
 278 */
 279void __init cleanup_highmap(void)
 280{
 281        unsigned long vaddr = __START_KERNEL_map;
 282        unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1;
 283        pmd_t *pmd = level2_kernel_pgt;
 284        pmd_t *last_pmd = pmd + PTRS_PER_PMD;
 285
 286        for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
 287                if (pmd_none(*pmd))
 288                        continue;
 289                if (vaddr < (unsigned long) _text || vaddr > end)
 290                        set_pmd(pmd, __pmd(0));
 291        }
 292}
 293
 294static unsigned long __initdata table_start;
 295static unsigned long __meminitdata table_end;
 296static unsigned long __meminitdata table_top;
 297
 298static __ref void *alloc_low_page(unsigned long *phys)
 299{
 300        unsigned long pfn = table_end++;
 301        void *adr;
 302
 303        if (after_bootmem) {
 304                adr = (void *)get_zeroed_page(GFP_ATOMIC);
 305                *phys = __pa(adr);
 306
 307                return adr;
 308        }
 309
 310        if (pfn >= table_top)
 311                panic("alloc_low_page: ran out of memory");
 312
 313        adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
 314        memset(adr, 0, PAGE_SIZE);
 315        *phys  = pfn * PAGE_SIZE;
 316        return adr;
 317}
 318
 319static __ref void unmap_low_page(void *adr)
 320{
 321        if (after_bootmem)
 322                return;
 323
 324        early_iounmap(adr, PAGE_SIZE);
 325}
 326
 327static unsigned long __meminit
 328phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
 329              pgprot_t prot)
 330{
 331        unsigned pages = 0;
 332        unsigned long last_map_addr = end;
 333        int i;
 334
 335        pte_t *pte = pte_page + pte_index(addr);
 336
 337        for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
 338
 339                if (addr >= end) {
 340                        if (!after_bootmem) {
 341                                for(; i < PTRS_PER_PTE; i++, pte++)
 342                                        set_pte(pte, __pte(0));
 343                        }
 344                        break;
 345                }
 346
 347                /*
 348                 * We will re-use the existing mapping.
 349                 * Xen for example has some special requirements, like mapping
 350                 * pagetable pages as RO. So assume someone who pre-setup
 351                 * these mappings are more intelligent.
 352                 */
 353                if (pte_val(*pte)) {
 354                        pages++;
 355                        continue;
 356                }
 357
 358                if (0)
 359                        printk("   pte=%p addr=%lx pte=%016lx\n",
 360                               pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 361                pages++;
 362                set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
 363                last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
 364        }
 365
 366        update_page_count(PG_LEVEL_4K, pages);
 367
 368        return last_map_addr;
 369}
 370
 371static unsigned long __meminit
 372phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end,
 373                pgprot_t prot)
 374{
 375        pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
 376
 377        return phys_pte_init(pte, address, end, prot);
 378}
 379
 380static unsigned long __meminit
 381phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 382              unsigned long page_size_mask, pgprot_t prot)
 383{
 384        unsigned long pages = 0;
 385        unsigned long last_map_addr = end;
 386
 387        int i = pmd_index(address);
 388
 389        for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
 390                unsigned long pte_phys;
 391                pmd_t *pmd = pmd_page + pmd_index(address);
 392                pte_t *pte;
 393                pgprot_t new_prot = prot;
 394
 395                if (address >= end) {
 396                        if (!after_bootmem) {
 397                                for (; i < PTRS_PER_PMD; i++, pmd++)
 398                                        set_pmd(pmd, __pmd(0));
 399                        }
 400                        break;
 401                }
 402
 403                if (pmd_val(*pmd)) {
 404                        if (!pmd_large(*pmd)) {
 405                                spin_lock(&init_mm.page_table_lock);
 406                                last_map_addr = phys_pte_update(pmd, address,
 407                                                                end, prot);
 408                                spin_unlock(&init_mm.page_table_lock);
 409                                continue;
 410                        }
 411                        /*
 412                         * If we are ok with PG_LEVEL_2M mapping, then we will
 413                         * use the existing mapping,
 414                         *
 415                         * Otherwise, we will split the large page mapping but
 416                         * use the same existing protection bits except for
 417                         * large page, so that we don't violate Intel's TLB
 418                         * Application note (317080) which says, while changing
 419                         * the page sizes, new and old translations should
 420                         * not differ with respect to page frame and
 421                         * attributes.
 422                         */
 423                        if (page_size_mask & (1 << PG_LEVEL_2M)) {
 424                                pages++;
 425                                continue;
 426                        }
 427                        new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 428                }
 429
 430                if (page_size_mask & (1<<PG_LEVEL_2M)) {
 431                        pages++;
 432                        spin_lock(&init_mm.page_table_lock);
 433                        set_pte((pte_t *)pmd,
 434                                pfn_pte(address >> PAGE_SHIFT,
 435                                        __pgprot(pgprot_val(prot) | _PAGE_PSE)));
 436                        spin_unlock(&init_mm.page_table_lock);
 437                        last_map_addr = (address & PMD_MASK) + PMD_SIZE;
 438                        continue;
 439                }
 440
 441                pte = alloc_low_page(&pte_phys);
 442                last_map_addr = phys_pte_init(pte, address, end, new_prot);
 443                unmap_low_page(pte);
 444
 445                spin_lock(&init_mm.page_table_lock);
 446                pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
 447                spin_unlock(&init_mm.page_table_lock);
 448        }
 449        update_page_count(PG_LEVEL_2M, pages);
 450        return last_map_addr;
 451}
 452
 453static unsigned long __meminit
 454phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
 455                unsigned long page_size_mask, pgprot_t prot)
 456{
 457        pmd_t *pmd = pmd_offset(pud, 0);
 458        unsigned long last_map_addr;
 459
 460        last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot);
 461        __flush_tlb_all();
 462        return last_map_addr;
 463}
 464
 465static unsigned long __meminit
 466phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 467                         unsigned long page_size_mask)
 468{
 469        unsigned long pages = 0;
 470        unsigned long last_map_addr = end;
 471        int i = pud_index(addr);
 472
 473        for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
 474                unsigned long pmd_phys;
 475                pud_t *pud = pud_page + pud_index(addr);
 476                pmd_t *pmd;
 477                pgprot_t prot = PAGE_KERNEL;
 478
 479                if (addr >= end)
 480                        break;
 481
 482                if (!after_bootmem &&
 483                                !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
 484                        set_pud(pud, __pud(0));
 485                        continue;
 486                }
 487
 488                if (pud_val(*pud)) {
 489                        if (!pud_large(*pud)) {
 490                                last_map_addr = phys_pmd_update(pud, addr, end,
 491                                                         page_size_mask, prot);
 492                                continue;
 493                        }
 494                        /*
 495                         * If we are ok with PG_LEVEL_1G mapping, then we will
 496                         * use the existing mapping.
 497                         *
 498                         * Otherwise, we will split the gbpage mapping but use
 499                         * the same existing protection  bits except for large
 500                         * page, so that we don't violate Intel's TLB
 501                         * Application note (317080) which says, while changing
 502                         * the page sizes, new and old translations should
 503                         * not differ with respect to page frame and
 504                         * attributes.
 505                         */
 506                        if (page_size_mask & (1 << PG_LEVEL_1G)) {
 507                                pages++;
 508                                continue;
 509                        }
 510                        prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 511                }
 512
 513                if (page_size_mask & (1<<PG_LEVEL_1G)) {
 514                        pages++;
 515                        spin_lock(&init_mm.page_table_lock);
 516                        set_pte((pte_t *)pud,
 517                                pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
 518                        spin_unlock(&init_mm.page_table_lock);
 519                        last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
 520                        continue;
 521                }
 522
 523                pmd = alloc_low_page(&pmd_phys);
 524                last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
 525                                              prot);
 526                unmap_low_page(pmd);
 527
 528                spin_lock(&init_mm.page_table_lock);
 529                pud_populate(&init_mm, pud, __va(pmd_phys));
 530                spin_unlock(&init_mm.page_table_lock);
 531        }
 532        __flush_tlb_all();
 533
 534        update_page_count(PG_LEVEL_1G, pages);
 535
 536        return last_map_addr;
 537}
 538
 539static unsigned long __meminit
 540phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
 541                 unsigned long page_size_mask)
 542{
 543        pud_t *pud;
 544
 545        pud = (pud_t *)pgd_page_vaddr(*pgd);
 546
 547        return phys_pud_init(pud, addr, end, page_size_mask);
 548}
 549
 550static void __init find_early_table_space(unsigned long end, int use_pse,
 551                                          int use_gbpages)
 552{
 553        unsigned long puds, pmds, ptes, tables, start;
 554
 555        puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
 556        tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
 557        if (use_gbpages) {
 558                unsigned long extra;
 559                extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
 560                pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
 561        } else
 562                pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
 563        tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
 564
 565        if (use_pse) {
 566                unsigned long extra;
 567                extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
 568                ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
 569        } else
 570                ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
 571        tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE);
 572
 573        /*
 574         * RED-PEN putting page tables only on node 0 could
 575         * cause a hotspot and fill up ZONE_DMA. The page tables
 576         * need roughly 0.5KB per GB.
 577         */
 578        start = 0x8000;
 579        table_start = find_e820_area(start, end, tables, PAGE_SIZE);
 580        if (table_start == -1UL)
 581                panic("Cannot find space for the kernel page tables");
 582
 583        table_start >>= PAGE_SHIFT;
 584        table_end = table_start;
 585        table_top = table_start + (tables >> PAGE_SHIFT);
 586
 587        printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
 588                end, table_start << PAGE_SHIFT, table_top << PAGE_SHIFT);
 589}
 590
 591static void __init init_gbpages(void)
 592{
 593        if (direct_gbpages && cpu_has_gbpages)
 594                printk(KERN_INFO "Using GB pages for direct mapping\n");
 595        else
 596                direct_gbpages = 0;
 597}
 598
 599static unsigned long __init kernel_physical_mapping_init(unsigned long start,
 600                                                unsigned long end,
 601                                                unsigned long page_size_mask)
 602{
 603
 604        unsigned long next, last_map_addr = end;
 605
 606        start = (unsigned long)__va(start);
 607        end = (unsigned long)__va(end);
 608
 609        for (; start < end; start = next) {
 610                pgd_t *pgd = pgd_offset_k(start);
 611                unsigned long pud_phys;
 612                pud_t *pud;
 613
 614                next = (start + PGDIR_SIZE) & PGDIR_MASK;
 615                if (next > end)
 616                        next = end;
 617
 618                if (pgd_val(*pgd)) {
 619                        last_map_addr = phys_pud_update(pgd, __pa(start),
 620                                                 __pa(end), page_size_mask);
 621                        continue;
 622                }
 623
 624                pud = alloc_low_page(&pud_phys);
 625                last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
 626                                                 page_size_mask);
 627                unmap_low_page(pud);
 628
 629                spin_lock(&init_mm.page_table_lock);
 630                pgd_populate(&init_mm, pgd, __va(pud_phys));
 631                spin_unlock(&init_mm.page_table_lock);
 632        }
 633        __flush_tlb_all();
 634
 635        return last_map_addr;
 636}
 637
 638struct map_range {
 639        unsigned long start;
 640        unsigned long end;
 641        unsigned page_size_mask;
 642};
 643
 644#define NR_RANGE_MR 5
 645
 646static int save_mr(struct map_range *mr, int nr_range,
 647                   unsigned long start_pfn, unsigned long end_pfn,
 648                   unsigned long page_size_mask)
 649{
 650
 651        if (start_pfn < end_pfn) {
 652                if (nr_range >= NR_RANGE_MR)
 653                        panic("run out of range for init_memory_mapping\n");
 654                mr[nr_range].start = start_pfn<<PAGE_SHIFT;
 655                mr[nr_range].end   = end_pfn<<PAGE_SHIFT;
 656                mr[nr_range].page_size_mask = page_size_mask;
 657                nr_range++;
 658        }
 659
 660        return nr_range;
 661}
 662
 663/*
 664 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
 665 * This runs before bootmem is initialized and gets pages directly from
 666 * the physical memory. To access them they are temporarily mapped.
 667 */
 668unsigned long __init_refok init_memory_mapping(unsigned long start,
 669                                               unsigned long end)
 670{
 671        unsigned long last_map_addr = 0;
 672        unsigned long page_size_mask = 0;
 673        unsigned long start_pfn, end_pfn;
 674        unsigned long pos;
 675
 676        struct map_range mr[NR_RANGE_MR];
 677        int nr_range, i;
 678        int use_pse, use_gbpages;
 679
 680        printk(KERN_INFO "init_memory_mapping: %016lx-%016lx\n", start, end);
 681
 682        /*
 683         * Find space for the kernel direct mapping tables.
 684         *
 685         * Later we should allocate these tables in the local node of the
 686         * memory mapped. Unfortunately this is done currently before the
 687         * nodes are discovered.
 688         */
 689        if (!after_bootmem)
 690                init_gbpages();
 691
 692#ifdef CONFIG_DEBUG_PAGEALLOC
 693        /*
 694         * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
 695         * This will simplify cpa(), which otherwise needs to support splitting
 696         * large pages into small in interrupt context, etc.
 697         */
 698        use_pse = use_gbpages = 0;
 699#else
 700        use_pse = cpu_has_pse;
 701        use_gbpages = direct_gbpages;
 702#endif
 703
 704        if (use_gbpages)
 705                page_size_mask |= 1 << PG_LEVEL_1G;
 706        if (use_pse)
 707                page_size_mask |= 1 << PG_LEVEL_2M;
 708
 709        memset(mr, 0, sizeof(mr));
 710        nr_range = 0;
 711
 712        /* head if not big page alignment ?*/
 713        start_pfn = start >> PAGE_SHIFT;
 714        pos = start_pfn << PAGE_SHIFT;
 715        end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT)
 716                        << (PMD_SHIFT - PAGE_SHIFT);
 717        if (start_pfn < end_pfn) {
 718                nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
 719                pos = end_pfn << PAGE_SHIFT;
 720        }
 721
 722        /* big page (2M) range*/
 723        start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
 724                         << (PMD_SHIFT - PAGE_SHIFT);
 725        end_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
 726                         << (PUD_SHIFT - PAGE_SHIFT);
 727        if (end_pfn > ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT)))
 728                end_pfn = ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT));
 729        if (start_pfn < end_pfn) {
 730                nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
 731                                page_size_mask & (1<<PG_LEVEL_2M));
 732                pos = end_pfn << PAGE_SHIFT;
 733        }
 734
 735        /* big page (1G) range */
 736        start_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
 737                         << (PUD_SHIFT - PAGE_SHIFT);
 738        end_pfn = (end >> PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
 739        if (start_pfn < end_pfn) {
 740                nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
 741                                page_size_mask &
 742                                 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
 743                pos = end_pfn << PAGE_SHIFT;
 744        }
 745
 746        /* tail is not big page (1G) alignment */
 747        start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
 748                         << (PMD_SHIFT - PAGE_SHIFT);
 749        end_pfn = (end >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
 750        if (start_pfn < end_pfn) {
 751                nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
 752                                page_size_mask & (1<<PG_LEVEL_2M));
 753                pos = end_pfn << PAGE_SHIFT;
 754        }
 755
 756        /* tail is not big page (2M) alignment */
 757        start_pfn = pos>>PAGE_SHIFT;
 758        end_pfn = end>>PAGE_SHIFT;
 759        nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
 760
 761        /* try to merge same page size and continuous */
 762        for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
 763                unsigned long old_start;
 764                if (mr[i].end != mr[i+1].start ||
 765                    mr[i].page_size_mask != mr[i+1].page_size_mask)
 766                        continue;
 767                /* move it */
 768                old_start = mr[i].start;
 769                memmove(&mr[i], &mr[i+1],
 770                         (nr_range - 1 - i) * sizeof (struct map_range));
 771                mr[i--].start = old_start;
 772                nr_range--;
 773        }
 774
 775        for (i = 0; i < nr_range; i++)
 776                printk(KERN_DEBUG " %010lx - %010lx page %s\n",
 777                                mr[i].start, mr[i].end,
 778                        (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
 779                         (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
 780
 781        if (!after_bootmem)
 782                find_early_table_space(end, use_pse, use_gbpages);
 783
 784        for (i = 0; i < nr_range; i++)
 785                last_map_addr = kernel_physical_mapping_init(
 786                                        mr[i].start, mr[i].end,
 787                                        mr[i].page_size_mask);
 788
 789        if (!after_bootmem)
 790                mmu_cr4_features = read_cr4();
 791        __flush_tlb_all();
 792
 793        if (!after_bootmem && table_end > table_start)
 794                reserve_early(table_start << PAGE_SHIFT,
 795                                 table_end << PAGE_SHIFT, "PGTABLE");
 796
 797        printk(KERN_INFO "last_map_addr: %lx end: %lx\n",
 798                         last_map_addr, end);
 799
 800        if (!after_bootmem)
 801                early_memtest(start, end);
 802
 803        return last_map_addr >> PAGE_SHIFT;
 804}
 805
 806#ifndef CONFIG_NUMA
 807void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn)
 808{
 809        unsigned long bootmap_size, bootmap;
 810
 811        bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
 812        bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size,
 813                                 PAGE_SIZE);
 814        if (bootmap == -1L)
 815                panic("Cannot find bootmem map of size %ld\n", bootmap_size);
 816        /* don't touch min_low_pfn */
 817        bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
 818                                         0, end_pfn);
 819        e820_register_active_regions(0, start_pfn, end_pfn);
 820        free_bootmem_with_active_regions(0, end_pfn);
 821        early_res_to_bootmem(0, end_pfn<<PAGE_SHIFT);
 822        reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);
 823}
 824
 825void __init paging_init(void)
 826{
 827        unsigned long max_zone_pfns[MAX_NR_ZONES];
 828
 829        memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 830        max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 831        max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 832        max_zone_pfns[ZONE_NORMAL] = max_pfn;
 833
 834        memory_present(0, 0, max_pfn);
 835        sparse_init();
 836        free_area_init_nodes(max_zone_pfns);
 837}
 838#endif
 839
 840/*
 841 * Memory hotplug specific functions
 842 */
 843#ifdef CONFIG_MEMORY_HOTPLUG
 844/*
 845 * Memory is added always to NORMAL zone. This means you will never get
 846 * additional DMA/DMA32 memory.
 847 */
 848int arch_add_memory(int nid, u64 start, u64 size)
 849{
 850        struct pglist_data *pgdat = NODE_DATA(nid);
 851        struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
 852        unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
 853        unsigned long nr_pages = size >> PAGE_SHIFT;
 854        int ret;
 855
 856        last_mapped_pfn = init_memory_mapping(start, start + size);
 857        if (last_mapped_pfn > max_pfn_mapped)
 858                max_pfn_mapped = last_mapped_pfn;
 859
 860        ret = __add_pages(zone, start_pfn, nr_pages);
 861        WARN_ON_ONCE(ret);
 862
 863        return ret;
 864}
 865EXPORT_SYMBOL_GPL(arch_add_memory);
 866
 867#if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
 868int memory_add_physaddr_to_nid(u64 start)
 869{
 870        return 0;
 871}
 872EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 873#endif
 874
 875#endif /* CONFIG_MEMORY_HOTPLUG */
 876
 877/*
 878 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
 879 * is valid. The argument is a physical page number.
 880 *
 881 *
 882 * On x86, access has to be given to the first megabyte of ram because that area
 883 * contains bios code and data regions used by X and dosemu and similar apps.
 884 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
 885 * mmio resources as well as potential bios/acpi data regions.
 886 */
 887int devmem_is_allowed(unsigned long pagenr)
 888{
 889        if (pagenr <= 256)
 890                return 1;
 891        if (!page_is_ram(pagenr))
 892                return 1;
 893        return 0;
 894}
 895
 896
 897static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
 898                         kcore_modules, kcore_vsyscall;
 899
 900void __init mem_init(void)
 901{
 902        long codesize, reservedpages, datasize, initsize;
 903        unsigned long absent_pages;
 904
 905        start_periodic_check_for_corruption();
 906
 907        pci_iommu_alloc();
 908
 909        /* clear_bss() already clear the empty_zero_page */
 910
 911        reservedpages = 0;
 912
 913        /* this will put all low memory onto the freelists */
 914#ifdef CONFIG_NUMA
 915        totalram_pages = numa_free_all_bootmem();
 916#else
 917        totalram_pages = free_all_bootmem();
 918#endif
 919
 920        absent_pages = absent_pages_in_range(0, max_pfn);
 921        reservedpages = max_pfn - totalram_pages - absent_pages;
 922        after_bootmem = 1;
 923
 924        codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 925        datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 926        initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 927
 928        /* Register memory areas for /proc/kcore */
 929        kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 930        kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 931                   VMALLOC_END-VMALLOC_START);
 932        kclist_add(&kcore_kernel, &_stext, _end - _stext);
 933        kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
 934        kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
 935                                 VSYSCALL_END - VSYSCALL_START);
 936
 937        printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 938                         "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n",
 939                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 940                max_pfn << (PAGE_SHIFT-10),
 941                codesize >> 10,
 942                absent_pages << (PAGE_SHIFT-10),
 943                reservedpages << (PAGE_SHIFT-10),
 944                datasize >> 10,
 945                initsize >> 10);
 946}
 947
 948void free_init_pages(char *what, unsigned long begin, unsigned long end)
 949{
 950        unsigned long addr = begin;
 951
 952        if (addr >= end)
 953                return;
 954
 955        /*
 956         * If debugging page accesses then do not free this memory but
 957         * mark them not present - any buggy init-section access will
 958         * create a kernel page fault:
 959         */
 960#ifdef CONFIG_DEBUG_PAGEALLOC
 961        printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
 962                begin, PAGE_ALIGN(end));
 963        set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
 964#else
 965        printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
 966
 967        for (; addr < end; addr += PAGE_SIZE) {
 968                ClearPageReserved(virt_to_page(addr));
 969                init_page_count(virt_to_page(addr));
 970                memset((void *)(addr & ~(PAGE_SIZE-1)),
 971                        POISON_FREE_INITMEM, PAGE_SIZE);
 972                free_page(addr);
 973                totalram_pages++;
 974        }
 975#endif
 976}
 977
 978void free_initmem(void)
 979{
 980        free_init_pages("unused kernel memory",
 981                        (unsigned long)(&__init_begin),
 982                        (unsigned long)(&__init_end));
 983}
 984
 985#ifdef CONFIG_DEBUG_RODATA
 986const int rodata_test_data = 0xC3;
 987EXPORT_SYMBOL_GPL(rodata_test_data);
 988
 989void mark_rodata_ro(void)
 990{
 991        unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
 992        unsigned long rodata_start =
 993                ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
 994
 995#ifdef CONFIG_DYNAMIC_FTRACE
 996        /* Dynamic tracing modifies the kernel text section */
 997        start = rodata_start;
 998#endif
 999
1000        printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1001               (end - start) >> 10);
1002        set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1003
1004        /*
1005         * The rodata section (but not the kernel text!) should also be
1006         * not-executable.
1007         */
1008        set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
1009
1010        rodata_test();
1011
1012#ifdef CONFIG_CPA_DEBUG
1013        printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1014        set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1015
1016        printk(KERN_INFO "Testing CPA: again\n");
1017        set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1018#endif
1019}
1020
1021#endif
1022
1023#ifdef CONFIG_BLK_DEV_INITRD
1024void free_initrd_mem(unsigned long start, unsigned long end)
1025{
1026        free_init_pages("initrd memory", start, end);
1027}
1028#endif
1029
1030int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
1031                                   int flags)
1032{
1033#ifdef CONFIG_NUMA
1034        int nid, next_nid;
1035        int ret;
1036#endif
1037        unsigned long pfn = phys >> PAGE_SHIFT;
1038
1039        if (pfn >= max_pfn) {
1040                /*
1041                 * This can happen with kdump kernels when accessing
1042                 * firmware tables:
1043                 */
1044                if (pfn < max_pfn_mapped)
1045                        return -EFAULT;
1046
1047                printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n",
1048                                phys, len);
1049                return -EFAULT;
1050        }
1051
1052        /* Should check here against the e820 map to avoid double free */
1053#ifdef CONFIG_NUMA
1054        nid = phys_to_nid(phys);
1055        next_nid = phys_to_nid(phys + len - 1);
1056        if (nid == next_nid)
1057                ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags);
1058        else
1059                ret = reserve_bootmem(phys, len, flags);
1060
1061        if (ret != 0)
1062                return ret;
1063
1064#else
1065        reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
1066#endif
1067
1068        if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
1069                dma_reserve += len / PAGE_SIZE;
1070                set_dma_reserve(dma_reserve);
1071        }
1072
1073        return 0;
1074}
1075
1076int kern_addr_valid(unsigned long addr)
1077{
1078        unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1079        pgd_t *pgd;
1080        pud_t *pud;
1081        pmd_t *pmd;
1082        pte_t *pte;
1083
1084        if (above != 0 && above != -1UL)
1085                return 0;
1086
1087        pgd = pgd_offset_k(addr);
1088        if (pgd_none(*pgd))
1089                return 0;
1090
1091        pud = pud_offset(pgd, addr);
1092        if (pud_none(*pud))
1093                return 0;
1094
1095        pmd = pmd_offset(pud, addr);
1096        if (pmd_none(*pmd))
1097                return 0;
1098
1099        if (pmd_large(*pmd))
1100                return pfn_valid(pmd_pfn(*pmd));
1101
1102        pte = pte_offset_kernel(pmd, addr);
1103        if (pte_none(*pte))
1104                return 0;
1105
1106        return pfn_valid(pte_pfn(*pte));
1107}
1108
1109/*
1110 * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
1111 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
1112 * not need special handling anymore:
1113 */
1114static struct vm_area_struct gate_vma = {
1115        .vm_start       = VSYSCALL_START,
1116        .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
1117        .vm_page_prot   = PAGE_READONLY_EXEC,
1118        .vm_flags       = VM_READ | VM_EXEC
1119};
1120
1121struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
1122{
1123#ifdef CONFIG_IA32_EMULATION
1124        if (test_tsk_thread_flag(tsk, TIF_IA32))
1125                return NULL;
1126#endif
1127        return &gate_vma;
1128}
1129
1130int in_gate_area(struct task_struct *task, unsigned long addr)
1131{
1132        struct vm_area_struct *vma = get_gate_vma(task);
1133
1134        if (!vma)
1135                return 0;
1136
1137        return (addr >= vma->vm_start) && (addr < vma->vm_end);
1138}
1139
1140/*
1141 * Use this when you have no reliable task/vma, typically from interrupt
1142 * context. It is less reliable than using the task's vma and may give
1143 * false positives:
1144 */
1145int in_gate_area_no_task(unsigned long addr)
1146{
1147        return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
1148}
1149
1150const char *arch_vma_name(struct vm_area_struct *vma)
1151{
1152        if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
1153                return "[vdso]";
1154        if (vma == &gate_vma)
1155                return "[vsyscall]";
1156        return NULL;
1157}
1158
1159#ifdef CONFIG_SPARSEMEM_VMEMMAP
1160/*
1161 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1162 */
1163static long __meminitdata addr_start, addr_end;
1164static void __meminitdata *p_start, *p_end;
1165static int __meminitdata node_start;
1166
1167int __meminit
1168vmemmap_populate(struct page *start_page, unsigned long size, int node)
1169{
1170        unsigned long addr = (unsigned long)start_page;
1171        unsigned long end = (unsigned long)(start_page + size);
1172        unsigned long next;
1173        pgd_t *pgd;
1174        pud_t *pud;
1175        pmd_t *pmd;
1176
1177        for (; addr < end; addr = next) {
1178                void *p = NULL;
1179
1180                pgd = vmemmap_pgd_populate(addr, node);
1181                if (!pgd)
1182                        return -ENOMEM;
1183
1184                pud = vmemmap_pud_populate(pgd, addr, node);
1185                if (!pud)
1186                        return -ENOMEM;
1187
1188                if (!cpu_has_pse) {
1189                        next = (addr + PAGE_SIZE) & PAGE_MASK;
1190                        pmd = vmemmap_pmd_populate(pud, addr, node);
1191
1192                        if (!pmd)
1193                                return -ENOMEM;
1194
1195                        p = vmemmap_pte_populate(pmd, addr, node);
1196
1197                        if (!p)
1198                                return -ENOMEM;
1199
1200                        addr_end = addr + PAGE_SIZE;
1201                        p_end = p + PAGE_SIZE;
1202                } else {
1203                        next = pmd_addr_end(addr, end);
1204
1205                        pmd = pmd_offset(pud, addr);
1206                        if (pmd_none(*pmd)) {
1207                                pte_t entry;
1208
1209                                p = vmemmap_alloc_block(PMD_SIZE, node);
1210                                if (!p)
1211                                        return -ENOMEM;
1212
1213                                entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1214                                                PAGE_KERNEL_LARGE);
1215                                set_pmd(pmd, __pmd(pte_val(entry)));
1216
1217                                /* check to see if we have contiguous blocks */
1218                                if (p_end != p || node_start != node) {
1219                                        if (p_start)
1220                                                printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1221                                                       addr_start, addr_end-1, p_start, p_end-1, node_start);
1222                                        addr_start = addr;
1223                                        node_start = node;
1224                                        p_start = p;
1225                                }
1226
1227                                addr_end = addr + PMD_SIZE;
1228                                p_end = p + PMD_SIZE;
1229                        } else
1230                                vmemmap_verify((pte_t *)pmd, node, addr, next);
1231                }
1232
1233        }
1234        return 0;
1235}
1236
1237void __meminit vmemmap_populate_print_last(void)
1238{
1239        if (p_start) {
1240                printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1241                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1242                p_start = NULL;
1243                p_end = NULL;
1244                node_start = 0;
1245        }
1246}
1247#endif
1248