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/mm.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/seq_file.h>
  12 #include <linux/debugfs.h>
  13 #include <linux/pfn.h>
  14 #include <linux/percpu.h>
  15 #include <linux/gfp.h>
  16 #include <linux/pci.h>
  17
  18 #include <asm/e820.h>
  19 #include <asm/processor.h>
  20 #include <asm/tlbflush.h>
  21 #include <asm/sections.h>
  22 #include <asm/setup.h>
  23 #include <asm/uaccess.h>
  24 #include <asm/pgalloc.h>
  25 #include <asm/proto.h>
  26 #include <asm/pat.h>
  27
  28 /*
  29  * The current flushing context - we pass it instead of 5 arguments:
  30  */
  31 struct cpa_data {
  32         unsigned long   *vaddr;
  33         pgd_t           *pgd;
  34         pgprot_t        mask_set;
  35         pgprot_t        mask_clr;
  36         int             numpages;
  37         int             flags;
  38         unsigned long   pfn;
  39         unsigned        force_split : 1;
  40         int             curpage;
  41         struct page     **pages;
  42 };
  43
  44 /*
  45  * Serialize cpa() (for !DEBUG_PAGEALLOC which uses large identity mappings)
  46  * using cpa_lock. So that we don't allow any other cpu, with stale large tlb
  47  * entries change the page attribute in parallel to some other cpu
  48  * splitting a large page entry along with changing the attribute.
  49  */
  50 static DEFINE_SPINLOCK(cpa_lock);
  51
  52 #define CPA_FLUSHTLB 1
  53 #define CPA_ARRAY 2
  54 #define CPA_PAGES_ARRAY 4
  55
  56 #ifdef CONFIG_PROC_FS
  57 static unsigned long direct_pages_count[PG_LEVEL_NUM];
  58
  59 void update_page_count(int level, unsigned long pages)
  60 {
  61         /* Protect against CPA */
  62         spin_lock(&pgd_lock);
  63         direct_pages_count[level] += pages;
  64         spin_unlock(&pgd_lock);
  65 }
  66
  67 static void split_page_count(int level)
  68 {
  69         direct_pages_count[level]--;
  70         direct_pages_count[level - 1] += PTRS_PER_PTE;
  71 }
  72
  73 void arch_report_meminfo(struct seq_file *m)
  74 {
  75         seq_printf(m, "DirectMap4k:    %8lu kB\n",
  76                         direct_pages_count[PG_LEVEL_4K] << 2);
  77 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
  78         seq_printf(m, "DirectMap2M:    %8lu kB\n",
  79                         direct_pages_count[PG_LEVEL_2M] << 11);
  80 #else
  81         seq_printf(m, "DirectMap4M:    %8lu kB\n",
  82                         direct_pages_count[PG_LEVEL_2M] << 12);
  83 #endif
  84 #ifdef CONFIG_X86_64
  85         if (direct_gbpages)
  86                 seq_printf(m, "DirectMap1G:    %8lu kB\n",
  87                         direct_pages_count[PG_LEVEL_1G] << 20);
  88 #endif
  89 }
  90 #else
  91 static inline void split_page_count(int level) { }
  92 #endif
  93
  94 #ifdef CONFIG_X86_64
  95
  96 static inline unsigned long highmap_start_pfn(void)
  97 {
  98         return __pa_symbol(_text) >> PAGE_SHIFT;
  99 }
 100
 101 static inline unsigned long highmap_end_pfn(void)
 102 {
 103         return __pa_symbol(roundup(_brk_end, PMD_SIZE)) >> PAGE_SHIFT;
 104 }
 105
 106 #endif
 107
 108 #ifdef CONFIG_DEBUG_PAGEALLOC
 109 # define debug_pagealloc 1
 110 #else
 111 # define debug_pagealloc 0
 112 #endif
 113
 114 static inline int
 115 within(unsigned long addr, unsigned long start, unsigned long end)
 116 {
 117         return addr >= start && addr < end;
 118 }
 119
 120 /*
 121  * Flushing functions
 122  */
 123
 124 /**
 125  * clflush_cache_range - flush a cache range with clflush
 126  * @vaddr:      virtual start address
 127  * @size:       number of bytes to flush
 128  *
 129  * clflush is an unordered instruction which needs fencing with mfence
 130  * to avoid ordering issues.
 131  */
 132 void clflush_cache_range(void *vaddr, unsigned int size)
 133 {
 134         void *vend = vaddr + size - 1;
 135
 136         mb();
 137
 138         for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size)
 139                 clflush(vaddr);
 140         /*
 141          * Flush any possible final partial cacheline:
 142          */
 143         clflush(vend);
 144
 145         mb();
 146 }
 147 EXPORT_SYMBOL_GPL(clflush_cache_range);
 148
 149 static void __cpa_flush_all(void *arg)
 150 {
 151         unsigned long cache = (unsigned long)arg;
 152
 153         /*
 154          * Flush all to work around Errata in early athlons regarding
 155          * large page flushing.
 156          */
 157         __flush_tlb_all();
 158
 159         if (cache && boot_cpu_data.x86 >= 4)
 160                 wbinvd();
 161 }
 162
 163 static void cpa_flush_all(unsigned long cache)
 164 {
 165         BUG_ON(irqs_disabled());
 166
 167         on_each_cpu(__cpa_flush_all, (void *) cache, 1);
 168 }
 169
 170 static void __cpa_flush_range(void *arg)
 171 {
 172         /*
 173          * We could optimize that further and do individual per page
 174          * tlb invalidates for a low number of pages. Caveat: we must
 175          * flush the high aliases on 64bit as well.
 176          */
 177         __flush_tlb_all();
 178 }
 179
 180 static void cpa_flush_range(unsigned long start, int numpages, int cache)
 181 {
 182         unsigned int i, level;
 183         unsigned long addr;
 184
 185         BUG_ON(irqs_disabled());
 186         WARN_ON(PAGE_ALIGN(start) != start);
 187
 188         on_each_cpu(__cpa_flush_range, NULL, 1);
 189
 190         if (!cache)
 191                 return;
 192
 193         /*
 194          * We only need to flush on one CPU,
 195          * clflush is a MESI-coherent instruction that
 196          * will cause all other CPUs to flush the same
 197          * cachelines:
 198          */
 199         for (i = 0, addr = start; i < numpages; i++, addr += PAGE_SIZE) {
 200                 pte_t *pte = lookup_address(addr, &level);
 201
 202                 /*
 203                  * Only flush present addresses:
 204                  */
 205                 if (pte && (pte_val(*pte) & _PAGE_PRESENT))
 206                         clflush_cache_range((void *) addr, PAGE_SIZE);
 207         }
 208 }
 209
 210 static void cpa_flush_array(unsigned long *start, int numpages, int cache,
 211                             int in_flags, struct page **pages)
 212 {
 213         unsigned int i, level;
 214         unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */
 215
 216         BUG_ON(irqs_disabled());
 217
 218         on_each_cpu(__cpa_flush_all, (void *) do_wbinvd, 1);
 219
 220         if (!cache || do_wbinvd)
 221                 return;
 222
 223         /*
 224          * We only need to flush on one CPU,
 225          * clflush is a MESI-coherent instruction that
 226          * will cause all other CPUs to flush the same
 227          * cachelines:
 228          */
 229         for (i = 0; i < numpages; i++) {
 230                 unsigned long addr;
 231                 pte_t *pte;
 232
 233                 if (in_flags & CPA_PAGES_ARRAY)
 234                         addr = (unsigned long)page_address(pages[i]);
 235                 else
 236                         addr = start[i];
 237
 238                 pte = lookup_address(addr, &level);
 239
 240                 /*
 241                  * Only flush present addresses:
 242                  */
 243                 if (pte && (pte_val(*pte) & _PAGE_PRESENT))
 244                         clflush_cache_range((void *)addr, PAGE_SIZE);
 245         }
 246 }
 247
 248 /*
 249  * Certain areas of memory on x86 require very specific protection flags,
 250  * for example the BIOS area or kernel text. Callers don't always get this
 251  * right (again, ioremap() on BIOS memory is not uncommon) so this function
 252  * checks and fixes these known static required protection bits.
 253  */
 254 static inline pgprot_t static_protections(pgprot_t prot, unsigned long address,
 255                                    unsigned long pfn)
 256 {
 257         pgprot_t forbidden = __pgprot(0);
 258
 259         /*
 260          * The BIOS area between 640k and 1Mb needs to be executable for
 261          * PCI BIOS based config access (CONFIG_PCI_GOBIOS) support.
 262          */
 263 #ifdef CONFIG_PCI_BIOS
 264         if (pcibios_enabled && within(pfn, BIOS_BEGIN >> PAGE_SHIFT, BIOS_END >> PAGE_SHIFT))
 265                 pgprot_val(forbidden) |= _PAGE_NX;
 266 #endif
 267
 268         /*
 269          * The kernel text needs to be executable for obvious reasons
 270          * Does not cover __inittext since that is gone later on. On
 271          * 64bit we do not enforce !NX on the low mapping
 272          */
 273         if (within(address, (unsigned long)_text, (unsigned long)_etext))
 274                 pgprot_val(forbidden) |= _PAGE_NX;
 275
 276         /*
 277          * The .rodata section needs to be read-only. Using the pfn
 278          * catches all aliases.
 279          */
 280         if (within(pfn, __pa_symbol(__start_rodata) >> PAGE_SHIFT,
 281                    __pa_symbol(__end_rodata) >> PAGE_SHIFT))
 282                 pgprot_val(forbidden) |= _PAGE_RW;
 283
 284 #if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA)
 285         /*
 286          * Once the kernel maps the text as RO (kernel_set_to_readonly is set),
 287          * kernel text mappings for the large page aligned text, rodata sections
 288          * will be always read-only. For the kernel identity mappings covering
 289          * the holes caused by this alignment can be anything that user asks.
 290          *
 291          * This will preserve the large page mappings for kernel text/data
 292          * at no extra cost.
 293          */
 294         if (kernel_set_to_readonly &&
 295             within(address, (unsigned long)_text,
 296                    (unsigned long)__end_rodata_hpage_align)) {
 297                 unsigned int level;
 298
 299                 /*
 300                  * Don't enforce the !RW mapping for the kernel text mapping,
 301                  * if the current mapping is already using small page mapping.
 302                  * No need to work hard to preserve large page mappings in this
 303                  * case.
 304                  *
 305                  * This also fixes the Linux Xen paravirt guest boot failure
 306                  * (because of unexpected read-only mappings for kernel identity
 307                  * mappings). In this paravirt guest case, the kernel text
 308                  * mapping and the kernel identity mapping share the same
 309                  * page-table pages. Thus we can't really use different
 310                  * protections for the kernel text and identity mappings. Also,
 311                  * these shared mappings are made of small page mappings.
 312                  * Thus this don't enforce !RW mapping for small page kernel
 313                  * text mapping logic will help Linux Xen parvirt guest boot
 314                  * as well.
 315                  */
 316                 if (lookup_address(address, &level) && (level != PG_LEVEL_4K))
 317                         pgprot_val(forbidden) |= _PAGE_RW;
 318         }
 319 #endif
 320
 321         prot = __pgprot(pgprot_val(prot) & ~pgprot_val(forbidden));
 322
 323         return prot;
 324 }
 325
 326 static pte_t *__lookup_address_in_pgd(pgd_t *pgd, unsigned long address,
 327                                       unsigned int *level)
 328 {
 329         pud_t *pud;
 330         pmd_t *pmd;
 331
 332         *level = PG_LEVEL_NONE;
 333
 334         if (pgd_none(*pgd))
 335                 return NULL;
 336
 337         pud = pud_offset(pgd, address);
 338         if (pud_none(*pud))
 339                 return NULL;
 340
 341         *level = PG_LEVEL_1G;
 342         if (pud_large(*pud) || !pud_present(*pud))
 343                 return (pte_t *)pud;
 344
 345         pmd = pmd_offset(pud, address);
 346         if (pmd_none(*pmd))
 347                 return NULL;
 348
 349         *level = PG_LEVEL_2M;
 350         if (pmd_large(*pmd) || !pmd_present(*pmd))
 351                 return (pte_t *)pmd;
 352
 353         *level = PG_LEVEL_4K;
 354
 355         return pte_offset_kernel(pmd, address);
 356 }
 357
 358 /*
 359  * Lookup the page table entry for a virtual address. Return a pointer
 360  * to the entry and the level of the mapping.
 361  *
 362  * Note: We return pud and pmd either when the entry is marked large
 363  * or when the present bit is not set. Otherwise we would return a
 364  * pointer to a nonexisting mapping.
 365  */
 366 pte_t *lookup_address(unsigned long address, unsigned int *level)
 367 {
 368         return __lookup_address_in_pgd(pgd_offset_k(address), address, level);
 369 }
 370 EXPORT_SYMBOL_GPL(lookup_address);
 371
 372 static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address,
 373                                   unsigned int *level)
 374 {
 375         if (cpa->pgd)
 376                 return __lookup_address_in_pgd(cpa->pgd + pgd_index(address),
 377                                                address, level);
 378
 379         return lookup_address(address, level);
 380 }
 381
 382 /*
 383  * This is necessary because __pa() does not work on some
 384  * kinds of memory, like vmalloc() or the alloc_remap()
 385  * areas on 32-bit NUMA systems.  The percpu areas can
 386  * end up in this kind of memory, for instance.
 387  *
 388  * This could be optimized, but it is only intended to be
 389  * used at inititalization time, and keeping it
 390  * unoptimized should increase the testing coverage for
 391  * the more obscure platforms.
 392  */
 393 phys_addr_t slow_virt_to_phys(void *__virt_addr)
 394 {
 395         unsigned long virt_addr = (unsigned long)__virt_addr;
 396         phys_addr_t phys_addr;
 397         unsigned long offset;
 398         enum pg_level level;
 399         unsigned long psize;
 400         unsigned long pmask;
 401         pte_t *pte;
 402
 403         pte = lookup_address(virt_addr, &level);
 404         BUG_ON(!pte);
 405         psize = page_level_size(level);
 406         pmask = page_level_mask(level);
 407         offset = virt_addr & ~pmask;
 408         phys_addr = pte_pfn(*pte) << PAGE_SHIFT;
 409         return (phys_addr | offset);
 410 }
 411 EXPORT_SYMBOL_GPL(slow_virt_to_phys);
 412
 413 /*
 414  * Set the new pmd in all the pgds we know about:
 415  */
 416 static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
 417 {
 418         /* change init_mm */
 419         set_pte_atomic(kpte, pte);
 420 #ifdef CONFIG_X86_32
 421         if (!SHARED_KERNEL_PMD) {
 422                 struct page *page;
 423
 424                 list_for_each_entry(page, &pgd_list, lru) {
 425                         pgd_t *pgd;
 426                         pud_t *pud;
 427                         pmd_t *pmd;
 428
 429                         pgd = (pgd_t *)page_address(page) + pgd_index(address);
 430                         pud = pud_offset(pgd, address);
 431                         pmd = pmd_offset(pud, address);
 432                         set_pte_atomic((pte_t *)pmd, pte);
 433                 }
 434         }
 435 #endif
 436 }
 437
 438 static int
 439 try_preserve_large_page(pte_t *kpte, unsigned long address,
 440                         struct cpa_data *cpa)
 441 {
 442         unsigned long nextpage_addr, numpages, pmask, psize, addr, pfn;
 443         pte_t new_pte, old_pte, *tmp;
 444         pgprot_t old_prot, new_prot, req_prot;
 445         int i, do_split = 1;
 446         enum pg_level level;
 447
 448         if (cpa->force_split)
 449                 return 1;
 450
 451         spin_lock(&pgd_lock);
 452         /*
 453          * Check for races, another CPU might have split this page
 454          * up already:
 455          */
 456         tmp = lookup_address(address, &level);
 457         if (tmp != kpte)
 458                 goto out_unlock;
 459
 460         switch (level) {
 461         case PG_LEVEL_2M:
 462 #ifdef CONFIG_X86_64
 463         case PG_LEVEL_1G:
 464 #endif
 465                 psize = page_level_size(level);
 466                 pmask = page_level_mask(level);
 467                 break;
 468         default:
 469                 do_split = -EINVAL;
 470                 goto out_unlock;
 471         }
 472
 473         /*
 474          * Calculate the number of pages, which fit into this large
 475          * page starting at address:
 476          */
 477         nextpage_addr = (address + psize) & pmask;
 478         numpages = (nextpage_addr - address) >> PAGE_SHIFT;
 479         if (numpages < cpa->numpages)
 480                 cpa->numpages = numpages;
 481
 482         /*
 483          * We are safe now. Check whether the new pgprot is the same:
 484          */
 485         old_pte = *kpte;
 486         old_prot = req_prot = pte_pgprot(old_pte);
 487
 488         pgprot_val(req_prot) &= ~pgprot_val(cpa->mask_clr);
 489         pgprot_val(req_prot) |= pgprot_val(cpa->mask_set);
 490
 491         /*
 492          * Set the PSE and GLOBAL flags only if the PRESENT flag is
 493          * set otherwise pmd_present/pmd_huge will return true even on
 494          * a non present pmd. The canon_pgprot will clear _PAGE_GLOBAL
 495          * for the ancient hardware that doesn't support it.
 496          */
 497         if (pgprot_val(req_prot) & _PAGE_PRESENT)
 498                 pgprot_val(req_prot) |= _PAGE_PSE | _PAGE_GLOBAL;
 499         else
 500                 pgprot_val(req_prot) &= ~(_PAGE_PSE | _PAGE_GLOBAL);
 501
 502         req_prot = canon_pgprot(req_prot);
 503
 504         /*
 505          * old_pte points to the large page base address. So we need
 506          * to add the offset of the virtual address:
 507          */
 508         pfn = pte_pfn(old_pte) + ((address & (psize - 1)) >> PAGE_SHIFT);
 509         cpa->pfn = pfn;
 510
 511         new_prot = static_protections(req_prot, address, pfn);
 512
 513         /*
 514          * We need to check the full range, whether
 515          * static_protection() requires a different pgprot for one of
 516          * the pages in the range we try to preserve:
 517          */
 518         addr = address & pmask;
 519         pfn = pte_pfn(old_pte);
 520         for (i = 0; i < (psize >> PAGE_SHIFT); i++, addr += PAGE_SIZE, pfn++) {
 521                 pgprot_t chk_prot = static_protections(req_prot, addr, pfn);
 522
 523                 if (pgprot_val(chk_prot) != pgprot_val(new_prot))
 524                         goto out_unlock;
 525         }
 526
 527         /*
 528          * If there are no changes, return. maxpages has been updated
 529          * above:
 530          */
 531         if (pgprot_val(new_prot) == pgprot_val(old_prot)) {
 532                 do_split = 0;
 533                 goto out_unlock;
 534         }
 535
 536         /*
 537          * We need to change the attributes. Check, whether we can
 538          * change the large page in one go. We request a split, when
 539          * the address is not aligned and the number of pages is
 540          * smaller than the number of pages in the large page. Note
 541          * that we limited the number of possible pages already to
 542          * the number of pages in the large page.
 543          */
 544         if (address == (address & pmask) && cpa->numpages == (psize >> PAGE_SHIFT)) {
 545                 /*
 546                  * The address is aligned and the number of pages
 547                  * covers the full page.
 548                  */
 549                 new_pte = pfn_pte(pte_pfn(old_pte), new_prot);
 550                 __set_pmd_pte(kpte, address, new_pte);
 551                 cpa->flags |= CPA_FLUSHTLB;
 552                 do_split = 0;
 553         }
 554
 555 out_unlock:
 556         spin_unlock(&pgd_lock);
 557
 558         return do_split;
 559 }
 560
 561 static int
 562 __split_large_page(pte_t *kpte, unsigned long address, struct page *base)
 563 {
 564         pte_t *pbase = (pte_t *)page_address(base);
 565         unsigned long pfn, pfninc = 1;
 566         unsigned int i, level;
 567         pte_t *tmp;
 568         pgprot_t ref_prot;
 569
 570         spin_lock(&pgd_lock);
 571         /*
 572          * Check for races, another CPU might have split this page
 573          * up for us already:
 574          */
 575         tmp = lookup_address(address, &level);
 576         if (tmp != kpte) {
 577                 spin_unlock(&pgd_lock);
 578                 return 1;
 579         }
 580
 581         paravirt_alloc_pte(&init_mm, page_to_pfn(base));
 582         ref_prot = pte_pgprot(pte_clrhuge(*kpte));
 583         /*
 584          * If we ever want to utilize the PAT bit, we need to
 585          * update this function to make sure it's converted from
 586          * bit 12 to bit 7 when we cross from the 2MB level to
 587          * the 4K level:
 588          */
 589         WARN_ON_ONCE(pgprot_val(ref_prot) & _PAGE_PAT_LARGE);
 590
 591 #ifdef CONFIG_X86_64
 592         if (level == PG_LEVEL_1G) {
 593                 pfninc = PMD_PAGE_SIZE >> PAGE_SHIFT;
 594                 /*
 595                  * Set the PSE flags only if the PRESENT flag is set
 596                  * otherwise pmd_present/pmd_huge will return true
 597                  * even on a non present pmd.
 598                  */
 599                 if (pgprot_val(ref_prot) & _PAGE_PRESENT)
 600                         pgprot_val(ref_prot) |= _PAGE_PSE;
 601                 else
 602                         pgprot_val(ref_prot) &= ~_PAGE_PSE;
 603         }
 604 #endif
 605
 606         /*
 607          * Set the GLOBAL flags only if the PRESENT flag is set
 608          * otherwise pmd/pte_present will return true even on a non
 609          * present pmd/pte. The canon_pgprot will clear _PAGE_GLOBAL
 610          * for the ancient hardware that doesn't support it.
 611          */
 612         if (pgprot_val(ref_prot) & _PAGE_PRESENT)
 613                 pgprot_val(ref_prot) |= _PAGE_GLOBAL;
 614         else
 615                 pgprot_val(ref_prot) &= ~_PAGE_GLOBAL;
 616
 617         /*
 618          * Get the target pfn from the original entry:
 619          */
 620         pfn = pte_pfn(*kpte);
 621         for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc)
 622                 set_pte(&pbase[i], pfn_pte(pfn, canon_pgprot(ref_prot)));
 623
 624         if (pfn_range_is_mapped(PFN_DOWN(__pa(address)),
 625                                 PFN_DOWN(__pa(address)) + 1))
 626                 split_page_count(level);
 627
 628         /*
 629          * Install the new, split up pagetable.
 630          *
 631          * We use the standard kernel pagetable protections for the new
 632          * pagetable protections, the actual ptes set above control the
 633          * primary protection behavior:
 634          */
 635         __set_pmd_pte(kpte, address, mk_pte(base, __pgprot(_KERNPG_TABLE)));
 636
 637         /*
 638          * Intel Atom errata AAH41 workaround.
 639          *
 640          * The real fix should be in hw or in a microcode update, but
 641          * we also probabilistically try to reduce the window of having
 642          * a large TLB mixed with 4K TLBs while instruction fetches are
 643          * going on.
 644          */
 645         __flush_tlb_all();
 646         spin_unlock(&pgd_lock);
 647
 648         return 0;
 649 }
 650
 651 static int split_large_page(pte_t *kpte, unsigned long address)
 652 {
 653         struct page *base;
 654
 655         if (!debug_pagealloc)
 656                 spin_unlock(&cpa_lock);
 657         base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
 658         if (!debug_pagealloc)
 659                 spin_lock(&cpa_lock);
 660         if (!base)
 661                 return -ENOMEM;
 662
 663         if (__split_large_page(kpte, address, base))
 664                 __free_page(base);
 665
 666         return 0;
 667 }
 668
 669 static bool try_to_free_pte_page(pte_t *pte)
 670 {
 671         int i;
 672
 673         for (i = 0; i < PTRS_PER_PTE; i++)
 674                 if (!pte_none(pte[i]))
 675                         return false;
 676
 677         free_page((unsigned long)pte);
 678         return true;
 679 }
 680
 681 static bool try_to_free_pmd_page(pmd_t *pmd)
 682 {
 683         int i;
 684
 685         for (i = 0; i < PTRS_PER_PMD; i++)
 686                 if (!pmd_none(pmd[i]))
 687                         return false;
 688
 689         free_page((unsigned long)pmd);
 690         return true;
 691 }
 692
 693 static bool unmap_pte_range(pmd_t *pmd, unsigned long start, unsigned long end)
 694 {
 695         pte_t *pte = pte_offset_kernel(pmd, start);
 696
 697         while (start < end) {
 698                 set_pte(pte, __pte(0));
 699
 700                 start += PAGE_SIZE;
 701                 pte++;
 702         }
 703
 704         if (try_to_free_pte_page((pte_t *)pmd_page_vaddr(*pmd))) {
 705                 pmd_clear(pmd);
 706                 return true;
 707         }
 708         return false;
 709 }
 710
 711 static void __unmap_pmd_range(pud_t *pud, pmd_t *pmd,
 712                               unsigned long start, unsigned long end)
 713 {
 714         if (unmap_pte_range(pmd, start, end))
 715                 if (try_to_free_pmd_page((pmd_t *)pud_page_vaddr(*pud)))
 716                         pud_clear(pud);
 717 }
 718
 719 static void unmap_pmd_range(pud_t *pud, unsigned long start, unsigned long end)
 720 {
 721         pmd_t *pmd = pmd_offset(pud, start);
 722
 723         /*
 724          * Not on a 2MB page boundary?
 725          */
 726         if (start & (PMD_SIZE - 1)) {
 727                 unsigned long next_page = (start + PMD_SIZE) & PMD_MASK;
 728                 unsigned long pre_end = min_t(unsigned long, end, next_page);
 729
 730                 __unmap_pmd_range(pud, pmd, start, pre_end);
 731
 732                 start = pre_end;
 733                 pmd++;
 734         }
 735
 736         /*
 737          * Try to unmap in 2M chunks.
 738          */
 739         while (end - start >= PMD_SIZE) {
 740                 if (pmd_large(*pmd))
 741                         pmd_clear(pmd);
 742                 else
 743                         __unmap_pmd_range(pud, pmd, start, start + PMD_SIZE);
 744
 745                 start += PMD_SIZE;
 746                 pmd++;
 747         }
 748
 749         /*
 750          * 4K leftovers?
 751          */
 752         if (start < end)
 753                 return __unmap_pmd_range(pud, pmd, start, end);
 754
 755         /*
 756          * Try again to free the PMD page if haven't succeeded above.
 757          */
 758         if (!pud_none(*pud))
 759                 if (try_to_free_pmd_page((pmd_t *)pud_page_vaddr(*pud)))
 760                         pud_clear(pud);
 761 }
 762
 763 static void unmap_pud_range(pgd_t *pgd, unsigned long start, unsigned long end)
 764 {
 765         pud_t *pud = pud_offset(pgd, start);
 766
 767         /*
 768          * Not on a GB page boundary?
 769          */
 770         if (start & (PUD_SIZE - 1)) {
 771                 unsigned long next_page = (start + PUD_SIZE) & PUD_MASK;
 772                 unsigned long pre_end   = min_t(unsigned long, end, next_page);
 773
 774                 unmap_pmd_range(pud, start, pre_end);
 775
 776                 start = pre_end;
 777                 pud++;
 778         }
 779
 780         /*
 781          * Try to unmap in 1G chunks?
 782          */
 783         while (end - start >= PUD_SIZE) {
 784
 785                 if (pud_large(*pud))
 786                         pud_clear(pud);
 787                 else
 788                         unmap_pmd_range(pud, start, start + PUD_SIZE);
 789
 790                 start += PUD_SIZE;
 791                 pud++;
 792         }
 793
 794         /*
 795          * 2M leftovers?
 796          */
 797         if (start < end)
 798                 unmap_pmd_range(pud, start, end);
 799
 800         /*
 801          * No need to try to free the PUD page because we'll free it in
 802          * populate_pgd's error path
 803          */
 804 }
 805
 806 static int alloc_pte_page(pmd_t *pmd)
 807 {
 808         pte_t *pte = (pte_t *)get_zeroed_page(GFP_KERNEL | __GFP_NOTRACK);
 809         if (!pte)
 810                 return -1;
 811
 812         set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE));
 813         return 0;
 814 }
 815
 816 static int alloc_pmd_page(pud_t *pud)
 817 {
 818         pmd_t *pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL | __GFP_NOTRACK);
 819         if (!pmd)
 820                 return -1;
 821
 822         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
 823         return 0;
 824 }
 825
 826 static void populate_pte(struct cpa_data *cpa,
 827                          unsigned long start, unsigned long end,
 828                          unsigned num_pages, pmd_t *pmd, pgprot_t pgprot)
 829 {
 830         pte_t *pte;
 831
 832         pte = pte_offset_kernel(pmd, start);
 833
 834         while (num_pages-- && start < end) {
 835
 836                 /* deal with the NX bit */
 837                 if (!(pgprot_val(pgprot) & _PAGE_NX))
 838                         cpa->pfn &= ~_PAGE_NX;
 839
 840                 set_pte(pte, pfn_pte(cpa->pfn >> PAGE_SHIFT, pgprot));
 841
 842                 start    += PAGE_SIZE;
 843                 cpa->pfn += PAGE_SIZE;
 844                 pte++;
 845         }
 846 }
 847
 848 static int populate_pmd(struct cpa_data *cpa,
 849                         unsigned long start, unsigned long end,
 850                         unsigned num_pages, pud_t *pud, pgprot_t pgprot)
 851 {
 852         unsigned int cur_pages = 0;
 853         pmd_t *pmd;
 854
 855         /*
 856          * Not on a 2M boundary?
 857          */
 858         if (start & (PMD_SIZE - 1)) {
 859                 unsigned long pre_end = start + (num_pages << PAGE_SHIFT);
 860                 unsigned long next_page = (start + PMD_SIZE) & PMD_MASK;
 861
 862                 pre_end   = min_t(unsigned long, pre_end, next_page);
 863                 cur_pages = (pre_end - start) >> PAGE_SHIFT;
 864                 cur_pages = min_t(unsigned int, num_pages, cur_pages);
 865
 866                 /*
 867                  * Need a PTE page?
 868                  */
 869                 pmd = pmd_offset(pud, start);
 870                 if (pmd_none(*pmd))
 871                         if (alloc_pte_page(pmd))
 872                                 return -1;
 873
 874                 populate_pte(cpa, start, pre_end, cur_pages, pmd, pgprot);
 875
 876                 start = pre_end;
 877         }
 878
 879         /*
 880          * We mapped them all?
 881          */
 882         if (num_pages == cur_pages)
 883                 return cur_pages;
 884
 885         while (end - start >= PMD_SIZE) {
 886
 887                 /*
 888                  * We cannot use a 1G page so allocate a PMD page if needed.
 889                  */
 890                 if (pud_none(*pud))
 891                         if (alloc_pmd_page(pud))
 892                                 return -1;
 893
 894                 pmd = pmd_offset(pud, start);
 895
 896                 set_pmd(pmd, __pmd(cpa->pfn | _PAGE_PSE | massage_pgprot(pgprot)));
 897
 898                 start     += PMD_SIZE;
 899                 cpa->pfn  += PMD_SIZE;
 900                 cur_pages += PMD_SIZE >> PAGE_SHIFT;
 901         }
 902
 903         /*
 904          * Map trailing 4K pages.
 905          */
 906         if (start < end) {
 907                 pmd = pmd_offset(pud, start);
 908                 if (pmd_none(*pmd))
 909                         if (alloc_pte_page(pmd))
 910                                 return -1;
 911
 912                 populate_pte(cpa, start, end, num_pages - cur_pages,
 913                              pmd, pgprot);
 914         }
 915         return num_pages;
 916 }
 917
 918 static int populate_pud(struct cpa_data *cpa, unsigned long start, pgd_t *pgd,
 919                         pgprot_t pgprot)
 920 {
 921         pud_t *pud;
 922         unsigned long end;
 923         int cur_pages = 0;
 924
 925         end = start + (cpa->numpages << PAGE_SHIFT);
 926
 927         /*
 928          * Not on a Gb page boundary? => map everything up to it with
 929          * smaller pages.
 930          */
 931         if (start & (PUD_SIZE - 1)) {
 932                 unsigned long pre_end;
 933                 unsigned long next_page = (start + PUD_SIZE) & PUD_MASK;
 934
 935                 pre_end   = min_t(unsigned long, end, next_page);
 936                 cur_pages = (pre_end - start) >> PAGE_SHIFT;
 937                 cur_pages = min_t(int, (int)cpa->numpages, cur_pages);
 938
 939                 pud = pud_offset(pgd, start);
 940
 941                 /*
 942                  * Need a PMD page?
 943                  */
 944                 if (pud_none(*pud))
 945                         if (alloc_pmd_page(pud))
 946                                 return -1;
 947
 948                 cur_pages = populate_pmd(cpa, start, pre_end, cur_pages,
 949                                          pud, pgprot);
 950                 if (cur_pages < 0)
 951                         return cur_pages;
 952
 953                 start = pre_end;
 954         }
 955
 956         /* We mapped them all? */
 957         if (cpa->numpages == cur_pages)
 958                 return cur_pages;
 959
 960         pud = pud_offset(pgd, start);
 961
 962         /*
 963          * Map everything starting from the Gb boundary, possibly with 1G pages
 964          */
 965         while (end - start >= PUD_SIZE) {
 966                 set_pud(pud, __pud(cpa->pfn | _PAGE_PSE | massage_pgprot(pgprot)));
 967
 968                 start     += PUD_SIZE;
 969                 cpa->pfn  += PUD_SIZE;
 970                 cur_pages += PUD_SIZE >> PAGE_SHIFT;
 971                 pud++;
 972         }
 973
 974         /* Map trailing leftover */
 975         if (start < end) {
 976                 int tmp;
 977
 978                 pud = pud_offset(pgd, start);
 979                 if (pud_none(*pud))
 980                         if (alloc_pmd_page(pud))
 981                                 return -1;
 982
 983                 tmp = populate_pmd(cpa, start, end, cpa->numpages - cur_pages,
 984                                    pud, pgprot);
 985                 if (tmp < 0)
 986                         return cur_pages;
 987
 988                 cur_pages += tmp;
 989         }
 990         return cur_pages;
 991 }
 992
 993 /*
 994  * Restrictions for kernel page table do not necessarily apply when mapping in
 995  * an alternate PGD.
 996  */
 997 static int populate_pgd(struct cpa_data *cpa, unsigned long addr)
 998 {
 999         pgprot_t pgprot = __pgprot(_KERNPG_TABLE);
1000         bool allocd_pgd = false;
1001         pgd_t *pgd_entry;
1002         pud_t *pud = NULL;      /* shut up gcc */
1003         int ret;
1004
1005         pgd_entry = cpa->pgd + pgd_index(addr);
1006
1007         /*
1008          * Allocate a PUD page and hand it down for mapping.
1009          */
1010         if (pgd_none(*pgd_entry)) {
1011                 pud = (pud_t *)get_zeroed_page(GFP_KERNEL | __GFP_NOTRACK);
1012                 if (!pud)
1013                         return -1;
1014
1015                 set_pgd(pgd_entry, __pgd(__pa(pud) | _KERNPG_TABLE));
1016                 allocd_pgd = true;
1017         }
1018
1019         pgprot_val(pgprot) &= ~pgprot_val(cpa->mask_clr);
1020         pgprot_val(pgprot) |=  pgprot_val(cpa->mask_set);
1021
1022         ret = populate_pud(cpa, addr, pgd_entry, pgprot);
1023         if (ret < 0) {
1024                 unmap_pud_range(pgd_entry, addr,
1025                                 addr + (cpa->numpages << PAGE_SHIFT));
1026
1027                 if (allocd_pgd) {
1028                         /*
1029                          * If I allocated this PUD page, I can just as well
1030                          * free it in this error path.
1031                          */
1032                         pgd_clear(pgd_entry);
1033                         free_page((unsigned long)pud);
1034                 }
1035                 return ret;
1036         }
1037         cpa->numpages = ret;
1038         return 0;
1039 }
1040
1041 static int __cpa_process_fault(struct cpa_data *cpa, unsigned long vaddr,
1042                                int primary)
1043 {
1044         /*
1045          * Ignore all non primary paths.
1046          */
1047         if (!primary)
1048                 return 0;
1049
1050         /*
1051          * Ignore the NULL PTE for kernel identity mapping, as it is expected
1052          * to have holes.
1053          * Also set numpages to '1' indicating that we processed cpa req for
1054          * one virtual address page and its pfn. TBD: numpages can be set based
1055          * on the initial value and the level returned by lookup_address().
1056          */
1057         if (within(vaddr, PAGE_OFFSET,
1058                    PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))) {
1059                 cpa->numpages = 1;
1060                 cpa->pfn = __pa(vaddr) >> PAGE_SHIFT;
1061                 return 0;
1062         } else {
1063                 WARN(1, KERN_WARNING "CPA: called for zero pte. "
1064                         "vaddr = %lx cpa->vaddr = %lx\n", vaddr,
1065                         *cpa->vaddr);
1066
1067                 return -EFAULT;
1068         }
1069 }
1070
1071 static int __change_page_attr(struct cpa_data *cpa, int primary)
1072 {
1073         unsigned long address;
1074         int do_split, err;
1075         unsigned int level;
1076         pte_t *kpte, old_pte;
1077
1078         if (cpa->flags & CPA_PAGES_ARRAY) {
1079                 struct page *page = cpa->pages[cpa->curpage];
1080                 if (unlikely(PageHighMem(page)))
1081                         return 0;
1082                 address = (unsigned long)page_address(page);
1083         } else if (cpa->flags & CPA_ARRAY)
1084                 address = cpa->vaddr[cpa->curpage];
1085         else
1086                 address = *cpa->vaddr;
1087 repeat:
1088         kpte = lookup_address(address, &level);
1089         if (!kpte)
1090                 return __cpa_process_fault(cpa, address, primary);
1091
1092         old_pte = *kpte;
1093         if (!pte_val(old_pte))
1094                 return __cpa_process_fault(cpa, address, primary);
1095
1096         if (level == PG_LEVEL_4K) {
1097                 pte_t new_pte;
1098                 pgprot_t new_prot = pte_pgprot(old_pte);
1099                 unsigned long pfn = pte_pfn(old_pte);
1100
1101                 pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr);
1102                 pgprot_val(new_prot) |= pgprot_val(cpa->mask_set);
1103
1104                 new_prot = static_protections(new_prot, address, pfn);
1105
1106                 /*
1107                  * Set the GLOBAL flags only if the PRESENT flag is
1108                  * set otherwise pte_present will return true even on
1109                  * a non present pte. The canon_pgprot will clear
1110                  * _PAGE_GLOBAL for the ancient hardware that doesn't
1111                  * support it.
1112                  */
1113                 if (pgprot_val(new_prot) & _PAGE_PRESENT)
1114                         pgprot_val(new_prot) |= _PAGE_GLOBAL;
1115                 else
1116                         pgprot_val(new_prot) &= ~_PAGE_GLOBAL;
1117
1118                 /*
1119                  * We need to keep the pfn from the existing PTE,
1120                  * after all we're only going to change it's attributes
1121                  * not the memory it points to
1122                  */
1123                 new_pte = pfn_pte(pfn, canon_pgprot(new_prot));
1124                 cpa->pfn = pfn;
1125                 /*
1126                  * Do we really change anything ?
1127                  */
1128                 if (pte_val(old_pte) != pte_val(new_pte)) {
1129                         set_pte_atomic(kpte, new_pte);
1130                         cpa->flags |= CPA_FLUSHTLB;
1131                 }
1132                 cpa->numpages = 1;
1133                 return 0;
1134         }
1135
1136         /*
1137          * Check, whether we can keep the large page intact
1138          * and just change the pte:
1139          */
1140         do_split = try_preserve_large_page(kpte, address, cpa);
1141         /*
1142          * When the range fits into the existing large page,
1143          * return. cp->numpages and cpa->tlbflush have been updated in
1144          * try_large_page:
1145          */
1146         if (do_split <= 0)
1147                 return do_split;
1148
1149         /*
1150          * We have to split the large page:
1151          */
1152         err = split_large_page(kpte, address);
1153         if (!err) {
1154                 /*
1155                  * Do a global flush tlb after splitting the large page
1156                  * and before we do the actual change page attribute in the PTE.
1157                  *
1158                  * With out this, we violate the TLB application note, that says
1159                  * "The TLBs may contain both ordinary and large-page
1160                  *  translations for a 4-KByte range of linear addresses. This
1161                  *  may occur if software modifies the paging structures so that
1162                  *  the page size used for the address range changes. If the two
1163                  *  translations differ with respect to page frame or attributes
1164                  *  (e.g., permissions), processor behavior is undefined and may
1165                  *  be implementation-specific."
1166                  *
1167                  * We do this global tlb flush inside the cpa_lock, so that we
1168                  * don't allow any other cpu, with stale tlb entries change the
1169                  * page attribute in parallel, that also falls into the
1170                  * just split large page entry.
1171                  */
1172                 flush_tlb_all();
1173                 goto repeat;
1174         }
1175
1176         return err;
1177 }
1178
1179 static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias);
1180
1181 static int cpa_process_alias(struct cpa_data *cpa)
1182 {
1183         struct cpa_data alias_cpa;
1184         unsigned long laddr = (unsigned long)__va(cpa->pfn << PAGE_SHIFT);
1185         unsigned long vaddr;
1186         int ret;
1187
1188         if (!pfn_range_is_mapped(cpa->pfn, cpa->pfn + 1))
1189                 return 0;
1190
1191         /*
1192          * No need to redo, when the primary call touched the direct
1193          * mapping already:
1194          */
1195         if (cpa->flags & CPA_PAGES_ARRAY) {
1196                 struct page *page = cpa->pages[cpa->curpage];
1197                 if (unlikely(PageHighMem(page)))
1198                         return 0;
1199                 vaddr = (unsigned long)page_address(page);
1200         } else if (cpa->flags & CPA_ARRAY)
1201                 vaddr = cpa->vaddr[cpa->curpage];
1202         else
1203                 vaddr = *cpa->vaddr;
1204
1205         if (!(within(vaddr, PAGE_OFFSET,
1206                     PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT)))) {
1207
1208                 alias_cpa = *cpa;
1209                 alias_cpa.vaddr = &laddr;
1210                 alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY);
1211
1212                 ret = __change_page_attr_set_clr(&alias_cpa, 0);
1213                 if (ret)
1214                         return ret;
1215         }
1216
1217 #ifdef CONFIG_X86_64
1218         /*
1219          * If the primary call didn't touch the high mapping already
1220          * and the physical address is inside the kernel map, we need
1221          * to touch the high mapped kernel as well:
1222          */
1223         if (!within(vaddr, (unsigned long)_text, _brk_end) &&
1224             within(cpa->pfn, highmap_start_pfn(), highmap_end_pfn())) {
1225                 unsigned long temp_cpa_vaddr = (cpa->pfn << PAGE_SHIFT) +
1226                                                __START_KERNEL_map - phys_base;
1227                 alias_cpa = *cpa;
1228                 alias_cpa.vaddr = &temp_cpa_vaddr;
1229                 alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY);
1230
1231                 /*
1232                  * The high mapping range is imprecise, so ignore the
1233                  * return value.
1234                  */
1235                 __change_page_attr_set_clr(&alias_cpa, 0);
1236         }
1237 #endif
1238
1239         return 0;
1240 }
1241
1242 static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
1243 {
1244         int ret, numpages = cpa->numpages;
1245
1246         while (numpages) {
1247                 /*
1248                  * Store the remaining nr of pages for the large page
1249                  * preservation check.
1250                  */
1251                 cpa->numpages = numpages;
1252                 /* for array changes, we can't use large page */
1253                 if (cpa->flags & (CPA_ARRAY | CPA_PAGES_ARRAY))
1254                         cpa->numpages = 1;
1255
1256                 if (!debug_pagealloc)
1257                         spin_lock(&cpa_lock);
1258                 ret = __change_page_attr(cpa, checkalias);
1259                 if (!debug_pagealloc)
1260                         spin_unlock(&cpa_lock);
1261                 if (ret)
1262                         return ret;
1263
1264                 if (checkalias) {
1265                         ret = cpa_process_alias(cpa);
1266                         if (ret)
1267                                 return ret;
1268                 }
1269
1270                 /*
1271                  * Adjust the number of pages with the result of the
1272                  * CPA operation. Either a large page has been
1273                  * preserved or a single page update happened.
1274                  */
1275                 BUG_ON(cpa->numpages > numpages);
1276                 numpages -= cpa->numpages;
1277                 if (cpa->flags & (CPA_PAGES_ARRAY | CPA_ARRAY))
1278                         cpa->curpage++;
1279                 else
1280                         *cpa->vaddr += cpa->numpages * PAGE_SIZE;
1281
1282         }
1283         return 0;
1284 }
1285
1286 static inline int cache_attr(pgprot_t attr)
1287 {
1288         return pgprot_val(attr) &
1289                 (_PAGE_PAT | _PAGE_PAT_LARGE | _PAGE_PWT | _PAGE_PCD);
1290 }
1291
1292 static int change_page_attr_set_clr(unsigned long *addr, int numpages,
1293                                     pgprot_t mask_set, pgprot_t mask_clr,
1294                                     int force_split, int in_flag,
1295                                     struct page **pages)
1296 {
1297         struct cpa_data cpa;
1298         int ret, cache, checkalias;
1299         unsigned long baddr = 0;
1300
1301         /*
1302          * Check, if we are requested to change a not supported
1303          * feature:
1304          */
1305         mask_set = canon_pgprot(mask_set);
1306         mask_clr = canon_pgprot(mask_clr);
1307         if (!pgprot_val(mask_set) && !pgprot_val(mask_clr) && !force_split)
1308                 return 0;
1309
1310         /* Ensure we are PAGE_SIZE aligned */
1311         if (in_flag & CPA_ARRAY) {
1312                 int i;
1313                 for (i = 0; i < numpages; i++) {
1314                         if (addr[i] & ~PAGE_MASK) {
1315                                 addr[i] &= PAGE_MASK;
1316                                 WARN_ON_ONCE(1);
1317                         }
1318                 }
1319         } else if (!(in_flag & CPA_PAGES_ARRAY)) {
1320                 /*
1321                  * in_flag of CPA_PAGES_ARRAY implies it is aligned.
1322                  * No need to cehck in that case
1323                  */
1324                 if (*addr & ~PAGE_MASK) {
1325                         *addr &= PAGE_MASK;
1326                         /*
1327                          * People should not be passing in unaligned addresses:
1328                          */
1329                         WARN_ON_ONCE(1);
1330                 }
1331                 /*
1332                  * Save address for cache flush. *addr is modified in the call
1333                  * to __change_page_attr_set_clr() below.
1334                  */
1335                 baddr = *addr;
1336         }
1337
1338         /* Must avoid aliasing mappings in the highmem code */
1339         kmap_flush_unused();
1340
1341         vm_unmap_aliases();
1342
1343         cpa.vaddr = addr;
1344         cpa.pages = pages;
1345         cpa.numpages = numpages;
1346         cpa.mask_set = mask_set;
1347         cpa.mask_clr = mask_clr;
1348         cpa.flags = 0;
1349         cpa.curpage = 0;
1350         cpa.force_split = force_split;
1351
1352         if (in_flag & (CPA_ARRAY | CPA_PAGES_ARRAY))
1353                 cpa.flags |= in_flag;
1354
1355         /* No alias checking for _NX bit modifications */
1356         checkalias = (pgprot_val(mask_set) | pgprot_val(mask_clr)) != _PAGE_NX;
1357
1358         ret = __change_page_attr_set_clr(&cpa, checkalias);
1359
1360         /*
1361          * Check whether we really changed something:
1362          */
1363         if (!(cpa.flags & CPA_FLUSHTLB))
1364                 goto out;
1365
1366         /*
1367          * No need to flush, when we did not set any of the caching
1368          * attributes:
1369          */
1370         cache = cache_attr(mask_set);
1371
1372         /*
1373          * On success we use clflush, when the CPU supports it to
1374          * avoid the wbindv. If the CPU does not support it and in the
1375          * error case we fall back to cpa_flush_all (which uses
1376          * wbindv):
1377          */
1378         if (!ret && cpu_has_clflush) {
1379                 if (cpa.flags & (CPA_PAGES_ARRAY | CPA_ARRAY)) {
1380                         cpa_flush_array(addr, numpages, cache,
1381                                         cpa.flags, pages);
1382                 } else
1383                         cpa_flush_range(baddr, numpages, cache);
1384         } else
1385                 cpa_flush_all(cache);
1386
1387 out:
1388         return ret;
1389 }
1390
1391 static inline int change_page_attr_set(unsigned long *addr, int numpages,
1392                                        pgprot_t mask, int array)
1393 {
1394         return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0), 0,
1395                 (array ? CPA_ARRAY : 0), NULL);
1396 }
1397
1398 static inline int change_page_attr_clear(unsigned long *addr, int numpages,
1399                                          pgprot_t mask, int array)
1400 {
1401         return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask, 0,
1402                 (array ? CPA_ARRAY : 0), NULL);
1403 }
1404
1405 static inline int cpa_set_pages_array(struct page **pages, int numpages,
1406                                        pgprot_t mask)
1407 {
1408         return change_page_attr_set_clr(NULL, numpages, mask, __pgprot(0), 0,
1409                 CPA_PAGES_ARRAY, pages);
1410 }
1411
1412 static inline int cpa_clear_pages_array(struct page **pages, int numpages,
1413                                          pgprot_t mask)
1414 {
1415         return change_page_attr_set_clr(NULL, numpages, __pgprot(0), mask, 0,
1416                 CPA_PAGES_ARRAY, pages);
1417 }
1418
1419 int _set_memory_uc(unsigned long addr, int numpages)
1420 {
1421         /*
1422          * for now UC MINUS. see comments in ioremap_nocache()
1423          */
1424         return change_page_attr_set(&addr, numpages,
1425                                     __pgprot(_PAGE_CACHE_UC_MINUS), 0);
1426 }
1427
1428 int set_memory_uc(unsigned long addr, int numpages)
1429 {
1430         int ret;
1431
1432         /*
1433          * for now UC MINUS. see comments in ioremap_nocache()
1434          */
1435         ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,
1436                             _PAGE_CACHE_UC_MINUS, NULL);
1437         if (ret)
1438                 goto out_err;
1439
1440         ret = _set_memory_uc(addr, numpages);
1441         if (ret)
1442                 goto out_free;
1443
1444         return 0;
1445
1446 out_free:
1447         free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
1448 out_err:
1449         return ret;
1450 }
1451 EXPORT_SYMBOL(set_memory_uc);
1452
1453 static int _set_memory_array(unsigned long *addr, int addrinarray,
1454                 unsigned long new_type)
1455 {
1456         int i, j;
1457         int ret;
1458
1459         /*
1460          * for now UC MINUS. see comments in ioremap_nocache()
1461          */
1462         for (i = 0; i < addrinarray; i++) {
1463                 ret = reserve_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE,
1464                                         new_type, NULL);
1465                 if (ret)
1466                         goto out_free;
1467         }
1468
1469         ret = change_page_attr_set(addr, addrinarray,
1470                                     __pgprot(_PAGE_CACHE_UC_MINUS), 1);
1471
1472         if (!ret && new_type == _PAGE_CACHE_WC)
1473                 ret = change_page_attr_set_clr(addr, addrinarray,
1474                                                __pgprot(_PAGE_CACHE_WC),
1475                                                __pgprot(_PAGE_CACHE_MASK),
1476                                                0, CPA_ARRAY, NULL);
1477         if (ret)
1478                 goto out_free;
1479
1480         return 0;
1481
1482 out_free:
1483         for (j = 0; j < i; j++)
1484                 free_memtype(__pa(addr[j]), __pa(addr[j]) + PAGE_SIZE);
1485
1486         return ret;
1487 }
1488
1489 int set_memory_array_uc(unsigned long *addr, int addrinarray)
1490 {
1491         return _set_memory_array(addr, addrinarray, _PAGE_CACHE_UC_MINUS);
1492 }
1493 EXPORT_SYMBOL(set_memory_array_uc);
1494
1495 int set_memory_array_wc(unsigned long *addr, int addrinarray)
1496 {
1497         return _set_memory_array(addr, addrinarray, _PAGE_CACHE_WC);
1498 }
1499 EXPORT_SYMBOL(set_memory_array_wc);
1500
1501 int _set_memory_wc(unsigned long addr, int numpages)
1502 {
1503         int ret;
1504         unsigned long addr_copy = addr;
1505
1506         ret = change_page_attr_set(&addr, numpages,
1507                                     __pgprot(_PAGE_CACHE_UC_MINUS), 0);
1508         if (!ret) {
1509                 ret = change_page_attr_set_clr(&addr_copy, numpages,
1510                                                __pgprot(_PAGE_CACHE_WC),
1511                                                __pgprot(_PAGE_CACHE_MASK),
1512                                                0, 0, NULL);
1513         }
1514         return ret;
1515 }
1516
1517 int set_memory_wc(unsigned long addr, int numpages)
1518 {
1519         int ret;
1520
1521         if (!pat_enabled)
1522                 return set_memory_uc(addr, numpages);
1523
1524         ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,
1525                 _PAGE_CACHE_WC, NULL);
1526         if (ret)
1527                 goto out_err;
1528
1529         ret = _set_memory_wc(addr, numpages);
1530         if (ret)
1531                 goto out_free;
1532
1533         return 0;
1534
1535 out_free:
1536         free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
1537 out_err:
1538         return ret;
1539 }
1540 EXPORT_SYMBOL(set_memory_wc);
1541
1542 int _set_memory_wb(unsigned long addr, int numpages)
1543 {
1544         return change_page_attr_clear(&addr, numpages,
1545                                       __pgprot(_PAGE_CACHE_MASK), 0);
1546 }
1547
1548 int set_memory_wb(unsigned long addr, int numpages)
1549 {
1550         int ret;
1551
1552         ret = _set_memory_wb(addr, numpages);
1553         if (ret)
1554                 return ret;
1555
1556         free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
1557         return 0;
1558 }
1559 EXPORT_SYMBOL(set_memory_wb);
1560
1561 int set_memory_array_wb(unsigned long *addr, int addrinarray)
1562 {
1563         int i;
1564         int ret;
1565
1566         ret = change_page_attr_clear(addr, addrinarray,
1567                                       __pgprot(_PAGE_CACHE_MASK), 1);
1568         if (ret)
1569                 return ret;
1570
1571         for (i = 0; i < addrinarray; i++)
1572                 free_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE);
1573
1574         return 0;
1575 }
1576 EXPORT_SYMBOL(set_memory_array_wb);
1577
1578 int set_memory_x(unsigned long addr, int numpages)
1579 {
1580         if (!(__supported_pte_mask & _PAGE_NX))
1581                 return 0;
1582
1583         return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_NX), 0);
1584 }
1585 EXPORT_SYMBOL(set_memory_x);
1586
1587 int set_memory_nx(unsigned long addr, int numpages)
1588 {
1589         if (!(__supported_pte_mask & _PAGE_NX))
1590                 return 0;
1591
1592         return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_NX), 0);
1593 }
1594 EXPORT_SYMBOL(set_memory_nx);
1595
1596 int set_memory_ro(unsigned long addr, int numpages)
1597 {
1598         return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_RW), 0);
1599 }
1600 EXPORT_SYMBOL_GPL(set_memory_ro);
1601
1602 int set_memory_rw(unsigned long addr, int numpages)
1603 {
1604         return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_RW), 0);
1605 }
1606 EXPORT_SYMBOL_GPL(set_memory_rw);
1607
1608 int set_memory_np(unsigned long addr, int numpages)
1609 {
1610         return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_PRESENT), 0);
1611 }
1612
1613 int set_memory_4k(unsigned long addr, int numpages)
1614 {
1615         return change_page_attr_set_clr(&addr, numpages, __pgprot(0),
1616                                         __pgprot(0), 1, 0, NULL);
1617 }
1618
1619 int set_pages_uc(struct page *page, int numpages)
1620 {
1621         unsigned long addr = (unsigned long)page_address(page);
1622
1623         return set_memory_uc(addr, numpages);
1624 }
1625 EXPORT_SYMBOL(set_pages_uc);
1626
1627 static int _set_pages_array(struct page **pages, int addrinarray,
1628                 unsigned long new_type)
1629 {
1630         unsigned long start;
1631         unsigned long end;
1632         int i;
1633         int free_idx;
1634         int ret;
1635
1636         for (i = 0; i < addrinarray; i++) {
1637                 if (PageHighMem(pages[i]))
1638                         continue;
1639                 start = page_to_pfn(pages[i]) << PAGE_SHIFT;
1640                 end = start + PAGE_SIZE;
1641                 if (reserve_memtype(start, end, new_type, NULL))
1642                         goto err_out;
1643         }
1644
1645         ret = cpa_set_pages_array(pages, addrinarray,
1646                         __pgprot(_PAGE_CACHE_UC_MINUS));
1647         if (!ret && new_type == _PAGE_CACHE_WC)
1648                 ret = change_page_attr_set_clr(NULL, addrinarray,
1649                                                __pgprot(_PAGE_CACHE_WC),
1650                                                __pgprot(_PAGE_CACHE_MASK),
1651                                                0, CPA_PAGES_ARRAY, pages);
1652         if (ret)
1653                 goto err_out;
1654         return 0; /* Success */
1655 err_out:
1656         free_idx = i;
1657         for (i = 0; i < free_idx; i++) {
1658                 if (PageHighMem(pages[i]))
1659                         continue;
1660                 start = page_to_pfn(pages[i]) << PAGE_SHIFT;
1661                 end = start + PAGE_SIZE;
1662                 free_memtype(start, end);
1663         }
1664         return -EINVAL;
1665 }
1666
1667 int set_pages_array_uc(struct page **pages, int addrinarray)
1668 {
1669         return _set_pages_array(pages, addrinarray, _PAGE_CACHE_UC_MINUS);
1670 }
1671 EXPORT_SYMBOL(set_pages_array_uc);
1672
1673 int set_pages_array_wc(struct page **pages, int addrinarray)
1674 {
1675         return _set_pages_array(pages, addrinarray, _PAGE_CACHE_WC);
1676 }
1677 EXPORT_SYMBOL(set_pages_array_wc);
1678
1679 int set_pages_wb(struct page *page, int numpages)
1680 {
1681         unsigned long addr = (unsigned long)page_address(page);
1682
1683         return set_memory_wb(addr, numpages);
1684 }
1685 EXPORT_SYMBOL(set_pages_wb);
1686
1687 int set_pages_array_wb(struct page **pages, int addrinarray)
1688 {
1689         int retval;
1690         unsigned long start;
1691         unsigned long end;
1692         int i;
1693
1694         retval = cpa_clear_pages_array(pages, addrinarray,
1695                         __pgprot(_PAGE_CACHE_MASK));
1696         if (retval)
1697                 return retval;
1698
1699         for (i = 0; i < addrinarray; i++) {
1700                 if (PageHighMem(pages[i]))
1701                         continue;
1702                 start = page_to_pfn(pages[i]) << PAGE_SHIFT;
1703                 end = start + PAGE_SIZE;
1704                 free_memtype(start, end);
1705         }
1706
1707         return 0;
1708 }
1709 EXPORT_SYMBOL(set_pages_array_wb);
1710
1711 int set_pages_x(struct page *page, int numpages)
1712 {
1713         unsigned long addr = (unsigned long)page_address(page);
1714
1715         return set_memory_x(addr, numpages);
1716 }
1717 EXPORT_SYMBOL(set_pages_x);
1718
1719 int set_pages_nx(struct page *page, int numpages)
1720 {
1721         unsigned long addr = (unsigned long)page_address(page);
1722
1723         return set_memory_nx(addr, numpages);
1724 }
1725 EXPORT_SYMBOL(set_pages_nx);
1726
1727 int set_pages_ro(struct page *page, int numpages)
1728 {
1729         unsigned long addr = (unsigned long)page_address(page);
1730
1731         return set_memory_ro(addr, numpages);
1732 }
1733
1734 int set_pages_rw(struct page *page, int numpages)
1735 {
1736         unsigned long addr = (unsigned long)page_address(page);
1737
1738         return set_memory_rw(addr, numpages);
1739 }
1740
1741 #ifdef CONFIG_DEBUG_PAGEALLOC
1742
1743 static int __set_pages_p(struct page *page, int numpages)
1744 {
1745         unsigned long tempaddr = (unsigned long) page_address(page);
1746         struct cpa_data cpa = { .vaddr = &tempaddr,
1747                                 .numpages = numpages,
1748                                 .mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW),
1749                                 .mask_clr = __pgprot(0),
1750                                 .flags = 0};
1751
1752         /*
1753          * No alias checking needed for setting present flag. otherwise,
1754          * we may need to break large pages for 64-bit kernel text
1755          * mappings (this adds to complexity if we want to do this from
1756          * atomic context especially). Let's keep it simple!
1757          */
1758         return __change_page_attr_set_clr(&cpa, 0);
1759 }
1760
1761 static int __set_pages_np(struct page *page, int numpages)
1762 {
1763         unsigned long tempaddr = (unsigned long) page_address(page);
1764         struct cpa_data cpa = { .vaddr = &tempaddr,
1765                                 .numpages = numpages,
1766                                 .mask_set = __pgprot(0),
1767                                 .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW),
1768                                 .flags = 0};
1769
1770         /*
1771          * No alias checking needed for setting not present flag. otherwise,
1772          * we may need to break large pages for 64-bit kernel text
1773          * mappings (this adds to complexity if we want to do this from
1774          * atomic context especially). Let's keep it simple!
1775          */
1776         return __change_page_attr_set_clr(&cpa, 0);
1777 }
1778
1779 void kernel_map_pages(struct page *page, int numpages, int enable)
1780 {
1781         if (PageHighMem(page))
1782                 return;
1783         if (!enable) {
1784                 debug_check_no_locks_freed(page_address(page),
1785                                            numpages * PAGE_SIZE);
1786         }
1787
1788         /*
1789          * The return value is ignored as the calls cannot fail.
1790          * Large pages for identity mappings are not used at boot time
1791          * and hence no memory allocations during large page split.
1792          */
1793         if (enable)
1794                 __set_pages_p(page, numpages);
1795         else
1796                 __set_pages_np(page, numpages);
1797
1798         /*
1799          * We should perform an IPI and flush all tlbs,
1800          * but that can deadlock->flush only current cpu:
1801          */
1802         __flush_tlb_all();
1803
1804         arch_flush_lazy_mmu_mode();
1805 }
1806
1807 #ifdef CONFIG_HIBERNATION
1808
1809 bool kernel_page_present(struct page *page)
1810 {
1811         unsigned int level;
1812         pte_t *pte;
1813
1814         if (PageHighMem(page))
1815                 return false;
1816
1817         pte = lookup_address((unsigned long)page_address(page), &level);
1818         return (pte_val(*pte) & _PAGE_PRESENT);
1819 }
1820
1821 #endif /* CONFIG_HIBERNATION */
1822
1823 #endif /* CONFIG_DEBUG_PAGEALLOC */
1824
1825 /*
1826  * The testcases use internal knowledge of the implementation that shouldn't
1827  * be exposed to the rest of the kernel. Include these directly here.
1828  */
1829 #ifdef CONFIG_CPA_DEBUG
1830 #include "pageattr-test.c"
1831 #endif