arch/x86/mm/pageattr.c

   1 /*
   2  * Copyright 2002 Andi Kleen, SuSE Labs.
   3  * Thanks to Ben LaHaise for precious feedback.
   4  */
   5 #include <linux/highmem.h>
   6 #include <linux/bootmem.h>
   7 #include <linux/module.h>
   8 #include <linux/sched.h>
   9 #include <linux/slab.h>
  10 #include <linux/mm.h>
  11
  12 #include <asm/e820.h>
  13 #include <asm/processor.h>
  14 #include <asm/tlbflush.h>
  15 #include <asm/sections.h>
  16 #include <asm/uaccess.h>
  17 #include <asm/pgalloc.h>
  18
  19 struct cpa_data {
  20         unsigned long   vaddr;
  21         pgprot_t        mask_set;
  22         pgprot_t        mask_clr;
  23         int             numpages;
  24         int             flushtlb;
  25 };
  26
  27 enum {
  28         CPA_NO_SPLIT = 0,
  29         CPA_SPLIT,
  30 };
  31
  32 static inline int
  33 within(unsigned long addr, unsigned long start, unsigned long end)
  34 {
  35         return addr >= start && addr < end;
  36 }
  37
  38 /*
  39  * Flushing functions
  40  */
  41
  42 /**
  43  * clflush_cache_range - flush a cache range with clflush
  44  * @addr:       virtual start address
  45  * @size:       number of bytes to flush
  46  *
  47  * clflush is an unordered instruction which needs fencing with mfence
  48  * to avoid ordering issues.
  49  */
  50 void clflush_cache_range(void *vaddr, unsigned int size)
  51 {
  52         void *vend = vaddr + size - 1;
  53
  54         mb();
  55
  56         for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size)
  57                 clflush(vaddr);
  58         /*
  59          * Flush any possible final partial cacheline:
  60          */
  61         clflush(vend);
  62
  63         mb();
  64 }
  65
  66 static void __cpa_flush_all(void *arg)
  67 {
  68         unsigned long cache = (unsigned long)arg;
  69
  70         /*
  71          * Flush all to work around Errata in early athlons regarding
  72          * large page flushing.
  73          */
  74         __flush_tlb_all();
  75
  76         if (cache && boot_cpu_data.x86_model >= 4)
  77                 wbinvd();
  78 }
  79
  80 static void cpa_flush_all(unsigned long cache)
  81 {
  82         BUG_ON(irqs_disabled());
  83
  84         on_each_cpu(__cpa_flush_all, (void *) cache, 1, 1);
  85 }
  86
  87 static void __cpa_flush_range(void *arg)
  88 {
  89         /*
  90          * We could optimize that further and do individual per page
  91          * tlb invalidates for a low number of pages. Caveat: we must
  92          * flush the high aliases on 64bit as well.
  93          */
  94         __flush_tlb_all();
  95 }
  96
  97 static void cpa_flush_range(unsigned long start, int numpages, int cache)
  98 {
  99         unsigned int i, level;
 100         unsigned long addr;
 101
 102         BUG_ON(irqs_disabled());
 103         WARN_ON(PAGE_ALIGN(start) != start);
 104
 105         on_each_cpu(__cpa_flush_range, NULL, 1, 1);
 106
 107         if (!cache)
 108                 return;
 109
 110         /*
 111          * We only need to flush on one CPU,
 112          * clflush is a MESI-coherent instruction that
 113          * will cause all other CPUs to flush the same
 114          * cachelines:
 115          */
 116         for (i = 0, addr = start; i < numpages; i++, addr += PAGE_SIZE) {
 117                 pte_t *pte = lookup_address(addr, &level);
 118
 119                 /*
 120                  * Only flush present addresses:
 121                  */
 122                 if (pte && pte_present(*pte))
 123                         clflush_cache_range((void *) addr, PAGE_SIZE);
 124         }
 125 }
 126
 127 #define HIGH_MAP_START  __START_KERNEL_map
 128 #define HIGH_MAP_END    (__START_KERNEL_map + KERNEL_TEXT_SIZE)
 129
 130
 131 /*
 132  * Converts a virtual address to a X86-64 highmap address
 133  */
 134 static unsigned long virt_to_highmap(void *address)
 135 {
 136 #ifdef CONFIG_X86_64
 137         return __pa((unsigned long)address) + HIGH_MAP_START - phys_base;
 138 #else
 139         return (unsigned long)address;
 140 #endif
 141 }
 142
 143 /*
 144  * Certain areas of memory on x86 require very specific protection flags,
 145  * for example the BIOS area or kernel text. Callers don't always get this
 146  * right (again, ioremap() on BIOS memory is not uncommon) so this function
 147  * checks and fixes these known static required protection bits.
 148  */
 149 static inline pgprot_t static_protections(pgprot_t prot, unsigned long address)
 150 {
 151         pgprot_t forbidden = __pgprot(0);
 152
 153         /*
 154          * The BIOS area between 640k and 1Mb needs to be executable for
 155          * PCI BIOS based config access (CONFIG_PCI_GOBIOS) support.
 156          */
 157         if (within(__pa(address), BIOS_BEGIN, BIOS_END))
 158                 pgprot_val(forbidden) |= _PAGE_NX;
 159
 160         /*
 161          * The kernel text needs to be executable for obvious reasons
 162          * Does not cover __inittext since that is gone later on
 163          */
 164         if (within(address, (unsigned long)_text, (unsigned long)_etext))
 165                 pgprot_val(forbidden) |= _PAGE_NX;
 166         /*
 167          * Do the same for the x86-64 high kernel mapping
 168          */
 169         if (within(address, virt_to_highmap(_text), virt_to_highmap(_etext)))
 170                 pgprot_val(forbidden) |= _PAGE_NX;
 171
 172
 173 #ifdef CONFIG_DEBUG_RODATA
 174         /* The .rodata section needs to be read-only */
 175         if (within(address, (unsigned long)__start_rodata,
 176                                 (unsigned long)__end_rodata))
 177                 pgprot_val(forbidden) |= _PAGE_RW;
 178         /*
 179          * Do the same for the x86-64 high kernel mapping
 180          */
 181         if (within(address, virt_to_highmap(__start_rodata),
 182                                 virt_to_highmap(__end_rodata)))
 183                 pgprot_val(forbidden) |= _PAGE_RW;
 184 #endif
 185
 186         prot = __pgprot(pgprot_val(prot) & ~pgprot_val(forbidden));
 187
 188         return prot;
 189 }
 190
 191 pte_t *lookup_address(unsigned long address, int *level)
 192 {
 193         pgd_t *pgd = pgd_offset_k(address);
 194         pud_t *pud;
 195         pmd_t *pmd;
 196
 197         *level = PG_LEVEL_NONE;
 198
 199         if (pgd_none(*pgd))
 200                 return NULL;
 201         pud = pud_offset(pgd, address);
 202         if (pud_none(*pud))
 203                 return NULL;
 204         pmd = pmd_offset(pud, address);
 205         if (pmd_none(*pmd))
 206                 return NULL;
 207
 208         *level = PG_LEVEL_2M;
 209         if (pmd_large(*pmd))
 210                 return (pte_t *)pmd;
 211
 212         *level = PG_LEVEL_4K;
 213         return pte_offset_kernel(pmd, address);
 214 }
 215
 216 static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
 217 {
 218         /* change init_mm */
 219         set_pte_atomic(kpte, pte);
 220 #ifdef CONFIG_X86_32
 221         if (!SHARED_KERNEL_PMD) {
 222                 struct page *page;
 223
 224                 list_for_each_entry(page, &pgd_list, lru) {
 225                         pgd_t *pgd;
 226                         pud_t *pud;
 227                         pmd_t *pmd;
 228
 229                         pgd = (pgd_t *)page_address(page) + pgd_index(address);
 230                         pud = pud_offset(pgd, address);
 231                         pmd = pmd_offset(pud, address);
 232                         set_pte_atomic((pte_t *)pmd, pte);
 233                 }
 234         }
 235 #endif
 236 }
 237
 238 static int try_preserve_large_page(pte_t *kpte, unsigned long address,
 239                                    struct cpa_data *cpa)
 240 {
 241         unsigned long nextpage_addr, numpages, pmask, psize, flags;
 242         pte_t new_pte, old_pte, *tmp;
 243         pgprot_t old_prot, new_prot;
 244         int level, res = CPA_SPLIT;
 245
 246         spin_lock_irqsave(&pgd_lock, flags);
 247         /*
 248          * Check for races, another CPU might have split this page
 249          * up already:
 250          */
 251         tmp = lookup_address(address, &level);
 252         if (tmp != kpte)
 253                 goto out_unlock;
 254
 255         switch (level) {
 256         case PG_LEVEL_2M:
 257                 psize = LARGE_PAGE_SIZE;
 258                 pmask = LARGE_PAGE_MASK;
 259                 break;
 260         case PG_LEVEL_1G:
 261         default:
 262                 res = -EINVAL;
 263                 goto out_unlock;
 264         }
 265
 266         /*
 267          * Calculate the number of pages, which fit into this large
 268          * page starting at address:
 269          */
 270         nextpage_addr = (address + psize) & pmask;
 271         numpages = (nextpage_addr - address) >> PAGE_SHIFT;
 272         if (numpages < cpa->numpages)
 273                 cpa->numpages = numpages;
 274
 275         /*
 276          * We are safe now. Check whether the new pgprot is the same:
 277          */
 278         old_pte = *kpte;
 279         old_prot = new_prot = pte_pgprot(old_pte);
 280
 281         pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr);
 282         pgprot_val(new_prot) |= pgprot_val(cpa->mask_set);
 283         new_prot = static_protections(new_prot, address);
 284
 285         /*
 286          * If there are no changes, return. maxpages has been updated
 287          * above:
 288          */
 289         if (pgprot_val(new_prot) == pgprot_val(old_prot)) {
 290                 res = CPA_NO_SPLIT;
 291                 goto out_unlock;
 292         }
 293
 294         /*
 295          * We need to change the attributes. Check, whether we can
 296          * change the large page in one go. We request a split, when
 297          * the address is not aligned and the number of pages is
 298          * smaller than the number of pages in the large page. Note
 299          * that we limited the number of possible pages already to
 300          * the number of pages in the large page.
 301          */
 302         if (address == (nextpage_addr - psize) && cpa->numpages == numpages) {
 303                 /*
 304                  * The address is aligned and the number of pages
 305                  * covers the full page.
 306                  */
 307                 new_pte = pfn_pte(pte_pfn(old_pte), canon_pgprot(new_prot));
 308                 __set_pmd_pte(kpte, address, new_pte);
 309                 cpa->flushtlb = 1;
 310                 res = CPA_NO_SPLIT;
 311         }
 312
 313 out_unlock:
 314         spin_unlock_irqrestore(&pgd_lock, flags);
 315         return res;
 316 }
 317
 318 static int split_large_page(pte_t *kpte, unsigned long address)
 319 {
 320         pgprot_t ref_prot = pte_pgprot(pte_clrhuge(*kpte));
 321         gfp_t gfp_flags = GFP_KERNEL;
 322         unsigned long flags, addr, pfn;
 323         pte_t *pbase, *tmp;
 324         struct page *base;
 325         unsigned int i, level;
 326
 327 #ifdef CONFIG_DEBUG_PAGEALLOC
 328         gfp_flags = __GFP_HIGH | __GFP_NOFAIL | __GFP_NOWARN;
 329         gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
 330 #endif
 331         base = alloc_pages(gfp_flags, 0);
 332         if (!base)
 333                 return -ENOMEM;
 334
 335         spin_lock_irqsave(&pgd_lock, flags);
 336         /*
 337          * Check for races, another CPU might have split this page
 338          * up for us already:
 339          */
 340         tmp = lookup_address(address, &level);
 341         if (tmp != kpte) {
 342                 WARN_ON_ONCE(1);
 343                 goto out_unlock;
 344         }
 345
 346         address = __pa(address);
 347         addr = address & LARGE_PAGE_MASK;
 348         pbase = (pte_t *)page_address(base);
 349 #ifdef CONFIG_X86_32
 350         paravirt_alloc_pt(&init_mm, page_to_pfn(base));
 351 #endif
 352
 353         /*
 354          * Get the target pfn from the original entry:
 355          */
 356         pfn = pte_pfn(*kpte);
 357         for (i = 0; i < PTRS_PER_PTE; i++, pfn++)
 358                 set_pte(&pbase[i], pfn_pte(pfn, ref_prot));
 359
 360         /*
 361          * Install the new, split up pagetable. Important detail here:
 362          *
 363          * On Intel the NX bit of all levels must be cleared to make a
 364          * page executable. See section 4.13.2 of Intel 64 and IA-32
 365          * Architectures Software Developer's Manual).
 366          */
 367         ref_prot = pte_pgprot(pte_mkexec(pte_clrhuge(*kpte)));
 368         __set_pmd_pte(kpte, address, mk_pte(base, ref_prot));
 369         base = NULL;
 370
 371 out_unlock:
 372         spin_unlock_irqrestore(&pgd_lock, flags);
 373
 374         if (base)
 375                 __free_pages(base, 0);
 376
 377         return 0;
 378 }
 379
 380 static int __change_page_attr(unsigned long address, struct cpa_data *cpa)
 381 {
 382         struct page *kpte_page;
 383         int level, res;
 384         pte_t *kpte;
 385
 386 repeat:
 387         kpte = lookup_address(address, &level);
 388         if (!kpte)
 389                 return -EINVAL;
 390
 391         kpte_page = virt_to_page(kpte);
 392         BUG_ON(PageLRU(kpte_page));
 393         BUG_ON(PageCompound(kpte_page));
 394
 395         if (level == PG_LEVEL_4K) {
 396                 pte_t new_pte, old_pte = *kpte;
 397                 pgprot_t new_prot = pte_pgprot(old_pte);
 398
 399                 if(!pte_val(old_pte)) {
 400                         printk(KERN_WARNING "CPA: called for zero pte. "
 401                                "vaddr = %lx cpa->vaddr = %lx\n", address,
 402                                 cpa->vaddr);
 403                         WARN_ON(1);
 404                         return -EINVAL;
 405                 }
 406
 407                 pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr);
 408                 pgprot_val(new_prot) |= pgprot_val(cpa->mask_set);
 409
 410                 new_prot = static_protections(new_prot, address);
 411
 412                 /*
 413                  * We need to keep the pfn from the existing PTE,
 414                  * after all we're only going to change it's attributes
 415                  * not the memory it points to
 416                  */
 417                 new_pte = pfn_pte(pte_pfn(old_pte), canon_pgprot(new_prot));
 418
 419                 /*
 420                  * Do we really change anything ?
 421                  */
 422                 if (pte_val(old_pte) != pte_val(new_pte)) {
 423                         set_pte_atomic(kpte, new_pte);
 424                         cpa->flushtlb = 1;
 425                 }
 426                 cpa->numpages = 1;
 427                 return 0;
 428         }
 429
 430         /*
 431          * Check, whether we can keep the large page intact
 432          * and just change the pte:
 433          */
 434         res = try_preserve_large_page(kpte, address, cpa);
 435         if (res < 0)
 436                 return res;
 437
 438         /*
 439          * When the range fits into the existing large page,
 440          * return. cp->numpages and cpa->tlbflush have been updated in
 441          * try_large_page:
 442          */
 443         if (res == CPA_NO_SPLIT)
 444                 return 0;
 445
 446         /*
 447          * We have to split the large page:
 448          */
 449         res = split_large_page(kpte, address);
 450         if (res)
 451                 return res;
 452         cpa->flushtlb = 1;
 453         goto repeat;
 454 }
 455
 456 /**
 457  * change_page_attr_addr - Change page table attributes in linear mapping
 458  * @address: Virtual address in linear mapping.
 459  * @prot:    New page table attribute (PAGE_*)
 460  *
 461  * Change page attributes of a page in the direct mapping. This is a variant
 462  * of change_page_attr() that also works on memory holes that do not have
 463  * mem_map entry (pfn_valid() is false).
 464  *
 465  * See change_page_attr() documentation for more details.
 466  *
 467  * Modules and drivers should use the set_memory_* APIs instead.
 468  */
 469
 470 static int change_page_attr_addr(struct cpa_data *cpa)
 471 {
 472         int err;
 473         unsigned long address = cpa->vaddr;
 474
 475 #ifdef CONFIG_X86_64
 476         unsigned long phys_addr = __pa(address);
 477
 478         /*
 479          * If we are inside the high mapped kernel range, then we
 480          * fixup the low mapping first. __va() returns the virtual
 481          * address in the linear mapping:
 482          */
 483         if (within(address, HIGH_MAP_START, HIGH_MAP_END))
 484                 address = (unsigned long) __va(phys_addr);
 485 #endif
 486
 487         err = __change_page_attr(address, cpa);
 488         if (err)
 489                 return err;
 490
 491 #ifdef CONFIG_X86_64
 492         /*
 493          * If the physical address is inside the kernel map, we need
 494          * to touch the high mapped kernel as well:
 495          */
 496         if (within(phys_addr, 0, KERNEL_TEXT_SIZE)) {
 497                 /*
 498                  * Calc the high mapping address. See __phys_addr()
 499                  * for the non obvious details.
 500                  *
 501                  * Note that NX and other required permissions are
 502                  * checked in static_protections().
 503                  */
 504                 address = phys_addr + HIGH_MAP_START - phys_base;
 505
 506                 /*
 507                  * Our high aliases are imprecise, because we check
 508                  * everything between 0 and KERNEL_TEXT_SIZE, so do
 509                  * not propagate lookup failures back to users:
 510                  */
 511                 __change_page_attr(address, cpa);
 512         }
 513 #endif
 514         return err;
 515 }
 516
 517 static int __change_page_attr_set_clr(struct cpa_data *cpa)
 518 {
 519         int ret, numpages = cpa->numpages;
 520
 521         while (numpages) {
 522                 /*
 523                  * Store the remaining nr of pages for the large page
 524                  * preservation check.
 525                  */
 526                 cpa->numpages = numpages;
 527                 ret = change_page_attr_addr(cpa);
 528                 if (ret)
 529                         return ret;
 530
 531                 /*
 532                  * Adjust the number of pages with the result of the
 533                  * CPA operation. Either a large page has been
 534                  * preserved or a single page update happened.
 535                  */
 536                 BUG_ON(cpa->numpages > numpages);
 537                 numpages -= cpa->numpages;
 538                 cpa->vaddr += cpa->numpages * PAGE_SIZE;
 539         }
 540         return 0;
 541 }
 542
 543 static inline int cache_attr(pgprot_t attr)
 544 {
 545         return pgprot_val(attr) &
 546                 (_PAGE_PAT | _PAGE_PAT_LARGE | _PAGE_PWT | _PAGE_PCD);
 547 }
 548
 549 static int change_page_attr_set_clr(unsigned long addr, int numpages,
 550                                     pgprot_t mask_set, pgprot_t mask_clr)
 551 {
 552         struct cpa_data cpa;
 553         int ret, cache;
 554
 555         /*
 556          * Check, if we are requested to change a not supported
 557          * feature:
 558          */
 559         mask_set = canon_pgprot(mask_set);
 560         mask_clr = canon_pgprot(mask_clr);
 561         if (!pgprot_val(mask_set) && !pgprot_val(mask_clr))
 562                 return 0;
 563
 564         cpa.vaddr = addr;
 565         cpa.numpages = numpages;
 566         cpa.mask_set = mask_set;
 567         cpa.mask_clr = mask_clr;
 568         cpa.flushtlb = 0;
 569
 570         ret = __change_page_attr_set_clr(&cpa);
 571
 572         /*
 573          * Check whether we really changed something:
 574          */
 575         if (!cpa.flushtlb)
 576                 return ret;
 577
 578         /*
 579          * No need to flush, when we did not set any of the caching
 580          * attributes:
 581          */
 582         cache = cache_attr(mask_set);
 583
 584         /*
 585          * On success we use clflush, when the CPU supports it to
 586          * avoid the wbindv. If the CPU does not support it and in the
 587          * error case we fall back to cpa_flush_all (which uses
 588          * wbindv):
 589          */
 590         if (!ret && cpu_has_clflush)
 591                 cpa_flush_range(addr, numpages, cache);
 592         else
 593                 cpa_flush_all(cache);
 594
 595         return ret;
 596 }
 597
 598 static inline int change_page_attr_set(unsigned long addr, int numpages,
 599                                        pgprot_t mask)
 600 {
 601         return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0));
 602 }
 603
 604 static inline int change_page_attr_clear(unsigned long addr, int numpages,
 605                                          pgprot_t mask)
 606 {
 607         return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask);
 608 }
 609
 610 int set_memory_uc(unsigned long addr, int numpages)
 611 {
 612         return change_page_attr_set(addr, numpages,
 613                                     __pgprot(_PAGE_PCD | _PAGE_PWT));
 614 }
 615 EXPORT_SYMBOL(set_memory_uc);
 616
 617 int set_memory_wb(unsigned long addr, int numpages)
 618 {
 619         return change_page_attr_clear(addr, numpages,
 620                                       __pgprot(_PAGE_PCD | _PAGE_PWT));
 621 }
 622 EXPORT_SYMBOL(set_memory_wb);
 623
 624 int set_memory_x(unsigned long addr, int numpages)
 625 {
 626         return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_NX));
 627 }
 628 EXPORT_SYMBOL(set_memory_x);
 629
 630 int set_memory_nx(unsigned long addr, int numpages)
 631 {
 632         return change_page_attr_set(addr, numpages, __pgprot(_PAGE_NX));
 633 }
 634 EXPORT_SYMBOL(set_memory_nx);
 635
 636 int set_memory_ro(unsigned long addr, int numpages)
 637 {
 638         return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_RW));
 639 }
 640
 641 int set_memory_rw(unsigned long addr, int numpages)
 642 {
 643         return change_page_attr_set(addr, numpages, __pgprot(_PAGE_RW));
 644 }
 645
 646 int set_memory_np(unsigned long addr, int numpages)
 647 {
 648         return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_PRESENT));
 649 }
 650
 651 int set_pages_uc(struct page *page, int numpages)
 652 {
 653         unsigned long addr = (unsigned long)page_address(page);
 654
 655         return set_memory_uc(addr, numpages);
 656 }
 657 EXPORT_SYMBOL(set_pages_uc);
 658
 659 int set_pages_wb(struct page *page, int numpages)
 660 {
 661         unsigned long addr = (unsigned long)page_address(page);
 662
 663         return set_memory_wb(addr, numpages);
 664 }
 665 EXPORT_SYMBOL(set_pages_wb);
 666
 667 int set_pages_x(struct page *page, int numpages)
 668 {
 669         unsigned long addr = (unsigned long)page_address(page);
 670
 671         return set_memory_x(addr, numpages);
 672 }
 673 EXPORT_SYMBOL(set_pages_x);
 674
 675 int set_pages_nx(struct page *page, int numpages)
 676 {
 677         unsigned long addr = (unsigned long)page_address(page);
 678
 679         return set_memory_nx(addr, numpages);
 680 }
 681 EXPORT_SYMBOL(set_pages_nx);
 682
 683 int set_pages_ro(struct page *page, int numpages)
 684 {
 685         unsigned long addr = (unsigned long)page_address(page);
 686
 687         return set_memory_ro(addr, numpages);
 688 }
 689
 690 int set_pages_rw(struct page *page, int numpages)
 691 {
 692         unsigned long addr = (unsigned long)page_address(page);
 693
 694         return set_memory_rw(addr, numpages);
 695 }
 696
 697 #ifdef CONFIG_DEBUG_PAGEALLOC
 698
 699 static int __set_pages_p(struct page *page, int numpages)
 700 {
 701         struct cpa_data cpa = { .vaddr = (unsigned long) page_address(page),
 702                                 .numpages = numpages,
 703                                 .mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW),
 704                                 .mask_clr = __pgprot(0)};
 705
 706         return __change_page_attr_set_clr(&cpa);
 707 }
 708
 709 static int __set_pages_np(struct page *page, int numpages)
 710 {
 711         struct cpa_data cpa = { .vaddr = (unsigned long) page_address(page),
 712                                 .numpages = numpages,
 713                                 .mask_set = __pgprot(0),
 714                                 .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW)};
 715
 716         return __change_page_attr_set_clr(&cpa);
 717 }
 718
 719 void kernel_map_pages(struct page *page, int numpages, int enable)
 720 {
 721         if (PageHighMem(page))
 722                 return;
 723         if (!enable) {
 724                 debug_check_no_locks_freed(page_address(page),
 725                                            numpages * PAGE_SIZE);
 726         }
 727
 728         /*
 729          * If page allocator is not up yet then do not call c_p_a():
 730          */
 731         if (!debug_pagealloc_enabled)
 732                 return;
 733
 734         /*
 735          * The return value is ignored - the calls cannot fail,
 736          * large pages are disabled at boot time:
 737          */
 738         if (enable)
 739                 __set_pages_p(page, numpages);
 740         else
 741                 __set_pages_np(page, numpages);
 742
 743         /*
 744          * We should perform an IPI and flush all tlbs,
 745          * but that can deadlock->flush only current cpu:
 746          */
 747         __flush_tlb_all();
 748 }
 749 #endif
 750
 751 /*
 752  * The testcases use internal knowledge of the implementation that shouldn't
 753  * be exposed to the rest of the kernel. Include these directly here.
 754  */
 755 #ifdef CONFIG_CPA_DEBUG
 756 #include "pageattr-test.c"
 757 #endif