LXR linux/arch/mn10300/include/asm/pgtable.h

   1/* MN10300 Page table manipulators and constants
   2 *
   3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public Licence
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the Licence, or (at your option) any later version.
  10 *
  11 *
  12 * The Linux memory management assumes a three-level page table setup. On
  13 * the i386, we use that, but "fold" the mid level into the top-level page
  14 * table, so that we physically have the same two-level page table as the
  15 * i386 mmu expects.
  16 *
  17 * This file contains the functions and defines necessary to modify and use
  18 * the i386 page table tree for the purposes of the MN10300 TLB handler
  19 * functions.
  20 */
  21#ifndef _ASM_PGTABLE_H
  22#define _ASM_PGTABLE_H
  23
  24#include <asm/cpu-regs.h>
  25
  26#ifndef __ASSEMBLY__
  27#include <asm/processor.h>
  28#include <asm/cache.h>
  29#include <linux/threads.h>
  30
  31#include <asm/bitops.h>
  32
  33#include <linux/slab.h>
  34#include <linux/list.h>
  35#include <linux/spinlock.h>
  36
  37/*
  38 * ZERO_PAGE is a global shared page that is always zero: used
  39 * for zero-mapped memory areas etc..
  40 */
  41#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
  42extern unsigned long empty_zero_page[1024];
  43extern spinlock_t pgd_lock;
  44extern struct page *pgd_list;
  45
  46extern void pmd_ctor(void *, struct kmem_cache *, unsigned long);
  47extern void pgtable_cache_init(void);
  48extern void paging_init(void);
  49
  50#endif /* !__ASSEMBLY__ */
  51
  52/*
  53 * The Linux mn10300 paging architecture only implements both the traditional
  54 * 2-level page tables
  55 */
  56#define PGDIR_SHIFT     22
  57#define PTRS_PER_PGD    1024
  58#define PTRS_PER_PUD    1       /* we don't really have any PUD physically */
  59#define __PAGETABLE_PUD_FOLDED
  60#define PTRS_PER_PMD    1       /* we don't really have any PMD physically */
  61#define __PAGETABLE_PMD_FOLDED
  62#define PTRS_PER_PTE    1024
  63
  64#define PGD_SIZE        PAGE_SIZE
  65#define PMD_SIZE        (1UL << PMD_SHIFT)
  66#define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  67#define PGDIR_MASK      (~(PGDIR_SIZE - 1))
  68
  69#define USER_PTRS_PER_PGD       (TASK_SIZE / PGDIR_SIZE)
  70#define FIRST_USER_ADDRESS      0UL
  71
  72#define USER_PGD_PTRS           (PAGE_OFFSET >> PGDIR_SHIFT)
  73#define KERNEL_PGD_PTRS         (PTRS_PER_PGD - USER_PGD_PTRS)
  74
  75#define TWOLEVEL_PGDIR_SHIFT    22
  76#define BOOT_USER_PGD_PTRS      (__PAGE_OFFSET >> TWOLEVEL_PGDIR_SHIFT)
  77#define BOOT_KERNEL_PGD_PTRS    (1024 - BOOT_USER_PGD_PTRS)
  78
  79#ifndef __ASSEMBLY__
  80extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  81#endif
  82
  83/*
  84 * Unfortunately, due to the way the MMU works on the MN10300, the vmalloc VM
  85 * area has to be in the lower half of the virtual address range (the upper
  86 * half is not translated through the TLB).
  87 *
  88 * So in this case, the vmalloc area goes at the bottom of the address map
  89 * (leaving a hole at the very bottom to catch addressing errors), and
  90 * userspace starts immediately above.
  91 *
  92 * The vmalloc() routines also leaves a hole of 4kB between each vmalloced
  93 * area to catch addressing errors.
  94 */
  95#ifndef __ASSEMBLY__
  96#define VMALLOC_OFFSET  (8UL * 1024 * 1024)
  97#define VMALLOC_START   (0x70000000UL)
  98#define VMALLOC_END     (0x7C000000UL)
  99#else
 100#define VMALLOC_OFFSET  (8 * 1024 * 1024)
 101#define VMALLOC_START   (0x70000000)
 102#define VMALLOC_END     (0x7C000000)
 103#endif
 104
 105#ifndef __ASSEMBLY__
 106extern pte_t kernel_vmalloc_ptes[(VMALLOC_END - VMALLOC_START) / PAGE_SIZE];
 107#endif
 108
 109/* IPTEL2/DPTEL2 bit assignments */
 110#define _PAGE_BIT_VALID         xPTEL2_V_BIT
 111#define _PAGE_BIT_CACHE         xPTEL2_C_BIT
 112#define _PAGE_BIT_PRESENT       xPTEL2_PV_BIT
 113#define _PAGE_BIT_DIRTY         xPTEL2_D_BIT
 114#define _PAGE_BIT_GLOBAL        xPTEL2_G_BIT
 115#define _PAGE_BIT_ACCESSED      xPTEL2_UNUSED1_BIT      /* mustn't be loaded into IPTEL2/DPTEL2 */
 116
 117#define _PAGE_VALID             xPTEL2_V
 118#define _PAGE_CACHE             xPTEL2_C
 119#define _PAGE_PRESENT           xPTEL2_PV
 120#define _PAGE_DIRTY             xPTEL2_D
 121#define _PAGE_PROT              xPTEL2_PR
 122#define _PAGE_PROT_RKNU         xPTEL2_PR_ROK
 123#define _PAGE_PROT_WKNU         xPTEL2_PR_RWK
 124#define _PAGE_PROT_RKRU         xPTEL2_PR_ROK_ROU
 125#define _PAGE_PROT_WKRU         xPTEL2_PR_RWK_ROU
 126#define _PAGE_PROT_WKWU         xPTEL2_PR_RWK_RWU
 127#define _PAGE_GLOBAL            xPTEL2_G
 128#define _PAGE_PS_MASK           xPTEL2_PS
 129#define _PAGE_PS_4Kb            xPTEL2_PS_4Kb
 130#define _PAGE_PS_128Kb          xPTEL2_PS_128Kb
 131#define _PAGE_PS_1Kb            xPTEL2_PS_1Kb
 132#define _PAGE_PS_4Mb            xPTEL2_PS_4Mb
 133#define _PAGE_PSE               xPTEL2_PS_4Mb           /* 4MB page */
 134#define _PAGE_CACHE_WT          xPTEL2_CWT
 135#define _PAGE_ACCESSED          xPTEL2_UNUSED1
 136#define _PAGE_NX                0                       /* no-execute bit */
 137
 138/* If _PAGE_VALID is clear, we use these: */
 139#define _PAGE_PROTNONE          0x000           /* If not present */
 140
 141#define __PAGE_PROT_UWAUX       0x010
 142#define __PAGE_PROT_USER        0x020
 143#define __PAGE_PROT_WRITE       0x040
 144
 145#define _PAGE_PRESENTV          (_PAGE_PRESENT|_PAGE_VALID)
 146
 147#ifndef __ASSEMBLY__
 148
 149#define VMALLOC_VMADDR(x) ((unsigned long)(x))
 150
 151#define _PAGE_TABLE     (_PAGE_PRESENTV | _PAGE_PROT_WKNU | _PAGE_ACCESSED | _PAGE_DIRTY)
 152#define _PAGE_CHG_MASK  (PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
 153
 154#define __PAGE_NONE     (_PAGE_PRESENTV | _PAGE_PROT_RKNU | _PAGE_ACCESSED | _PAGE_CACHE)
 155#define __PAGE_SHARED   (_PAGE_PRESENTV | _PAGE_PROT_WKWU | _PAGE_ACCESSED | _PAGE_CACHE)
 156#define __PAGE_COPY     (_PAGE_PRESENTV | _PAGE_PROT_RKRU | _PAGE_ACCESSED | _PAGE_CACHE)
 157#define __PAGE_READONLY (_PAGE_PRESENTV | _PAGE_PROT_RKRU | _PAGE_ACCESSED | _PAGE_CACHE)
 158
 159#define PAGE_NONE               __pgprot(__PAGE_NONE     | _PAGE_NX)
 160#define PAGE_SHARED_NOEXEC      __pgprot(__PAGE_SHARED   | _PAGE_NX)
 161#define PAGE_COPY_NOEXEC        __pgprot(__PAGE_COPY     | _PAGE_NX)
 162#define PAGE_READONLY_NOEXEC    __pgprot(__PAGE_READONLY | _PAGE_NX)
 163#define PAGE_SHARED_EXEC        __pgprot(__PAGE_SHARED)
 164#define PAGE_COPY_EXEC          __pgprot(__PAGE_COPY)
 165#define PAGE_READONLY_EXEC      __pgprot(__PAGE_READONLY)
 166#define PAGE_COPY               PAGE_COPY_NOEXEC
 167#define PAGE_READONLY           PAGE_READONLY_NOEXEC
 168#define PAGE_SHARED             PAGE_SHARED_EXEC
 169
 170#define __PAGE_KERNEL_BASE (_PAGE_PRESENTV | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_GLOBAL)
 171
 172#define __PAGE_KERNEL           (__PAGE_KERNEL_BASE | _PAGE_PROT_WKNU | _PAGE_CACHE | _PAGE_NX)
 173#define __PAGE_KERNEL_NOCACHE   (__PAGE_KERNEL_BASE | _PAGE_PROT_WKNU | _PAGE_NX)
 174#define __PAGE_KERNEL_EXEC      (__PAGE_KERNEL & ~_PAGE_NX)
 175#define __PAGE_KERNEL_RO        (__PAGE_KERNEL_BASE | _PAGE_PROT_RKNU | _PAGE_CACHE | _PAGE_NX)
 176#define __PAGE_KERNEL_LARGE     (__PAGE_KERNEL | _PAGE_PSE)
 177#define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE)
 178
 179#define PAGE_KERNEL             __pgprot(__PAGE_KERNEL)
 180#define PAGE_KERNEL_RO          __pgprot(__PAGE_KERNEL_RO)
 181#define PAGE_KERNEL_EXEC        __pgprot(__PAGE_KERNEL_EXEC)
 182#define PAGE_KERNEL_NOCACHE     __pgprot(__PAGE_KERNEL_NOCACHE)
 183#define PAGE_KERNEL_LARGE       __pgprot(__PAGE_KERNEL_LARGE)
 184#define PAGE_KERNEL_LARGE_EXEC  __pgprot(__PAGE_KERNEL_LARGE_EXEC)
 185
 186#define __PAGE_USERIO           (__PAGE_KERNEL_BASE | _PAGE_PROT_WKWU | _PAGE_NX)
 187#define PAGE_USERIO             __pgprot(__PAGE_USERIO)
 188
 189/*
 190 * Whilst the MN10300 can do page protection for execute (given separate data
 191 * and insn TLBs), we are not supporting it at the moment. Write permission,
 192 * however, always implies read permission (but not execute permission).
 193 */
 194#define __P000  PAGE_NONE
 195#define __P001  PAGE_READONLY_NOEXEC
 196#define __P010  PAGE_COPY_NOEXEC
 197#define __P011  PAGE_COPY_NOEXEC
 198#define __P100  PAGE_READONLY_EXEC
 199#define __P101  PAGE_READONLY_EXEC
 200#define __P110  PAGE_COPY_EXEC
 201#define __P111  PAGE_COPY_EXEC
 202
 203#define __S000  PAGE_NONE
 204#define __S001  PAGE_READONLY_NOEXEC
 205#define __S010  PAGE_SHARED_NOEXEC
 206#define __S011  PAGE_SHARED_NOEXEC
 207#define __S100  PAGE_READONLY_EXEC
 208#define __S101  PAGE_READONLY_EXEC
 209#define __S110  PAGE_SHARED_EXEC
 210#define __S111  PAGE_SHARED_EXEC
 211
 212/*
 213 * Define this to warn about kernel memory accesses that are
 214 * done without a 'verify_area(VERIFY_WRITE,..)'
 215 */
 216#undef TEST_VERIFY_AREA
 217
 218#define pte_present(x)  (pte_val(x) & _PAGE_VALID)
 219#define pte_clear(mm, addr, xp)                         \
 220do {                                                    \
 221        set_pte_at((mm), (addr), (xp), __pte(0));       \
 222} while (0)
 223
 224#define pmd_none(x)     (!pmd_val(x))
 225#define pmd_present(x)  (!pmd_none(x))
 226#define pmd_clear(xp)   do { set_pmd(xp, __pmd(0)); } while (0)
 227#define pmd_bad(x)      0
 228
 229
 230#define pages_to_mb(x) ((x) >> (20 - PAGE_SHIFT))
 231
 232#ifndef __ASSEMBLY__
 233
 234/*
 235 * The following only work if pte_present() is true.
 236 * Undefined behaviour if not..
 237 */
 238static inline int pte_user(pte_t pte)   { return pte_val(pte) & __PAGE_PROT_USER; }
 239static inline int pte_read(pte_t pte)   { return pte_val(pte) & __PAGE_PROT_USER; }
 240static inline int pte_dirty(pte_t pte)  { return pte_val(pte) & _PAGE_DIRTY; }
 241static inline int pte_young(pte_t pte)  { return pte_val(pte) & _PAGE_ACCESSED; }
 242static inline int pte_write(pte_t pte)  { return pte_val(pte) & __PAGE_PROT_WRITE; }
 243static inline int pte_special(pte_t pte){ return 0; }
 244
 245static inline pte_t pte_rdprotect(pte_t pte)
 246{
 247        pte_val(pte) &= ~(__PAGE_PROT_USER|__PAGE_PROT_UWAUX); return pte;
 248}
 249static inline pte_t pte_exprotect(pte_t pte)
 250{
 251        pte_val(pte) |= _PAGE_NX; return pte;
 252}
 253
 254static inline pte_t pte_wrprotect(pte_t pte)
 255{
 256        pte_val(pte) &= ~(__PAGE_PROT_WRITE|__PAGE_PROT_UWAUX); return pte;
 257}
 258
 259static inline pte_t pte_mkclean(pte_t pte)      { pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
 260static inline pte_t pte_mkold(pte_t pte)        { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
 261static inline pte_t pte_mkdirty(pte_t pte)      { pte_val(pte) |= _PAGE_DIRTY; return pte; }
 262static inline pte_t pte_mkyoung(pte_t pte)      { pte_val(pte) |= _PAGE_ACCESSED; return pte; }
 263static inline pte_t pte_mkexec(pte_t pte)       { pte_val(pte) &= ~_PAGE_NX; return pte; }
 264
 265static inline pte_t pte_mkread(pte_t pte)
 266{
 267        pte_val(pte) |= __PAGE_PROT_USER;
 268        if (pte_write(pte))
 269                pte_val(pte) |= __PAGE_PROT_UWAUX;
 270        return pte;
 271}
 272static inline pte_t pte_mkwrite(pte_t pte)
 273{
 274        pte_val(pte) |= __PAGE_PROT_WRITE;
 275        if (pte_val(pte) & __PAGE_PROT_USER)
 276                pte_val(pte) |= __PAGE_PROT_UWAUX;
 277        return pte;
 278}
 279
 280static inline pte_t pte_mkspecial(pte_t pte)    { return pte; }
 281
 282#define pte_ERROR(e) \
 283        printk(KERN_ERR "%s:%d: bad pte %08lx.\n", \
 284               __FILE__, __LINE__, pte_val(e))
 285#define pgd_ERROR(e) \
 286        printk(KERN_ERR "%s:%d: bad pgd %08lx.\n", \
 287               __FILE__, __LINE__, pgd_val(e))
 288
 289/*
 290 * The "pgd_xxx()" functions here are trivial for a folded two-level
 291 * setup: the pgd is never bad, and a pmd always exists (as it's folded
 292 * into the pgd entry)
 293 */
 294#define pgd_clear(xp)                           do { } while (0)
 295
 296/*
 297 * Certain architectures need to do special things when PTEs
 298 * within a page table are directly modified.  Thus, the following
 299 * hook is made available.
 300 */
 301#define set_pte(pteptr, pteval)                 (*(pteptr) = pteval)
 302#define set_pte_at(mm, addr, ptep, pteval)      set_pte((ptep), (pteval))
 303#define set_pte_atomic(pteptr, pteval)          set_pte((pteptr), (pteval))
 304
 305/*
 306 * (pmds are folded into pgds so this doesn't get actually called,
 307 * but the define is needed for a generic inline function.)
 308 */
 309#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)
 310
 311#define ptep_get_and_clear(mm, addr, ptep) \
 312        __pte(xchg(&(ptep)->pte, 0))
 313#define pte_same(a, b)          (pte_val(a) == pte_val(b))
 314#define pte_page(x)             pfn_to_page(pte_pfn(x))
 315#define pte_none(x)             (!pte_val(x))
 316#define pte_pfn(x)              ((unsigned long) (pte_val(x) >> PAGE_SHIFT))
 317#define __pfn_addr(pfn)         ((pfn) << PAGE_SHIFT)
 318#define pfn_pte(pfn, prot)      __pte(__pfn_addr(pfn) | pgprot_val(prot))
 319#define pfn_pmd(pfn, prot)      __pmd(__pfn_addr(pfn) | pgprot_val(prot))
 320
 321/*
 322 * All present user pages are user-executable:
 323 */
 324static inline int pte_exec(pte_t pte)
 325{
 326        return pte_user(pte);
 327}
 328
 329/*
 330 * All present pages are kernel-executable:
 331 */
 332static inline int pte_exec_kernel(pte_t pte)
 333{
 334        return 1;
 335}
 336
 337/* Encode and de-code a swap entry */
 338#define __swp_type(x)                   (((x).val >> 1) & 0x3f)
 339#define __swp_offset(x)                 ((x).val >> 7)
 340#define __swp_entry(type, offset) \
 341        ((swp_entry_t) { ((type) << 1) | ((offset) << 7) })
 342#define __pte_to_swp_entry(pte)         ((swp_entry_t) { pte_val(pte) })
 343#define __swp_entry_to_pte(x)           __pte((x).val)
 344
 345static inline
 346int ptep_test_and_clear_dirty(struct vm_area_struct *vma, unsigned long addr,
 347                              pte_t *ptep)
 348{
 349        if (!pte_dirty(*ptep))
 350                return 0;
 351        return test_and_clear_bit(_PAGE_BIT_DIRTY, &ptep->pte);
 352}
 353
 354static inline
 355int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr,
 356                              pte_t *ptep)
 357{
 358        if (!pte_young(*ptep))
 359                return 0;
 360        return test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte);
 361}
 362
 363static inline
 364void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 365{
 366        pte_val(*ptep) &= ~(__PAGE_PROT_WRITE|__PAGE_PROT_UWAUX);
 367}
 368
 369static inline void ptep_mkdirty(pte_t *ptep)
 370{
 371        set_bit(_PAGE_BIT_DIRTY, &ptep->pte);
 372}
 373
 374/*
 375 * Macro to mark a page protection value as "uncacheable".  On processors which
 376 * do not support it, this is a no-op.
 377 */
 378#define pgprot_noncached(prot)  __pgprot(pgprot_val(prot) & ~_PAGE_CACHE)
 379
 380/*
 381 * Macro to mark a page protection value as "Write-Through".
 382 * On processors which do not support it, this is a no-op.
 383 */
 384#define pgprot_through(prot)    __pgprot(pgprot_val(prot) | _PAGE_CACHE_WT)
 385
 386/*
 387 * Conversion functions: convert a page and protection to a page entry,
 388 * and a page entry and page directory to the page they refer to.
 389 */
 390
 391#define mk_pte(page, pgprot)    pfn_pte(page_to_pfn(page), (pgprot))
 392#define mk_pte_huge(entry) \
 393        ((entry).pte |= _PAGE_PRESENT | _PAGE_PSE | _PAGE_VALID)
 394
 395static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 396{
 397        pte_val(pte) &= _PAGE_CHG_MASK;
 398        pte_val(pte) |= pgprot_val(newprot);
 399        return pte;
 400}
 401
 402#define page_pte(page)  page_pte_prot((page), __pgprot(0))
 403
 404#define pmd_page_kernel(pmd) \
 405        ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 406
 407#define pmd_page(pmd)   pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
 408
 409#define pmd_large(pmd) \
 410        ((pmd_val(pmd) & (_PAGE_PSE | _PAGE_PRESENT)) == \
 411         (_PAGE_PSE | _PAGE_PRESENT))
 412
 413/*
 414 * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
 415 *
 416 * this macro returns the index of the entry in the pgd page which would
 417 * control the given virtual address
 418 */
 419#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 420
 421/*
 422 * pgd_offset() returns a (pgd_t *)
 423 * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
 424 */
 425#define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
 426
 427/*
 428 * a shortcut which implies the use of the kernel's pgd, instead
 429 * of a process's
 430 */
 431#define pgd_offset_k(address)   pgd_offset(&init_mm, address)
 432
 433/*
 434 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
 435 *
 436 * this macro returns the index of the entry in the pmd page which would
 437 * control the given virtual address
 438 */
 439#define pmd_index(address) \
 440        (((address) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
 441
 442/*
 443 * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
 444 *
 445 * this macro returns the index of the entry in the pte page which would
 446 * control the given virtual address
 447 */
 448#define pte_index(address) \
 449        (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 450
 451#define pte_offset_kernel(dir, address) \
 452        ((pte_t *) pmd_page_kernel(*(dir)) +  pte_index(address))
 453
 454/*
 455 * Make a given kernel text page executable/non-executable.
 456 * Returns the previous executability setting of that page (which
 457 * is used to restore the previous state). Used by the SMP bootup code.
 458 * NOTE: this is an __init function for security reasons.
 459 */
 460static inline int set_kernel_exec(unsigned long vaddr, int enable)
 461{
 462        return 0;
 463}
 464
 465#define pte_offset_map(dir, address) \
 466        ((pte_t *) page_address(pmd_page(*(dir))) + pte_index(address))
 467#define pte_unmap(pte)          do {} while (0)
 468
 469/*
 470 * The MN10300 has external MMU info in the form of a TLB: this is adapted from
 471 * the kernel page tables containing the necessary information by tlb-mn10300.S
 472 */
 473extern void update_mmu_cache(struct vm_area_struct *vma,
 474                             unsigned long address, pte_t *ptep);
 475
 476#endif /* !__ASSEMBLY__ */
 477
 478#define kern_addr_valid(addr)   (1)
 479
 480#define MK_IOSPACE_PFN(space, pfn)      (pfn)
 481#define GET_IOSPACE(pfn)                0
 482#define GET_PFN(pfn)                    (pfn)
 483
 484#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 485#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
 486#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 487#define __HAVE_ARCH_PTEP_SET_WRPROTECT
 488#define __HAVE_ARCH_PTEP_MKDIRTY
 489#define __HAVE_ARCH_PTE_SAME
 490#include <asm-generic/pgtable.h>
 491
 492#endif /* !__ASSEMBLY__ */
 493
 494#endif /* _ASM_PGTABLE_H */
 495