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

   1/* pgtable.h: FR-V page table mangling
   2 *
   3 * Copyright (C) 2004 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 License
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the License, or (at your option) any later version.
  10 *
  11 * Derived from:
  12 *      include/asm-m68knommu/pgtable.h
  13 *      include/asm-i386/pgtable.h
  14 */
  15
  16#ifndef _ASM_PGTABLE_H
  17#define _ASM_PGTABLE_H
  18
  19#include <asm/mem-layout.h>
  20#include <asm/setup.h>
  21#include <asm/processor.h>
  22
  23#ifndef __ASSEMBLY__
  24#include <linux/threads.h>
  25#include <linux/slab.h>
  26#include <linux/list.h>
  27#include <linux/spinlock.h>
  28#include <linux/sched.h>
  29struct vm_area_struct;
  30#endif
  31
  32#ifndef __ASSEMBLY__
  33#if defined(CONFIG_HIGHPTE)
  34typedef unsigned long pte_addr_t;
  35#else
  36typedef pte_t *pte_addr_t;
  37#endif
  38#endif
  39
  40/*****************************************************************************/
  41/*
  42 * MMU-less operation case first
  43 */
  44#ifndef CONFIG_MMU
  45
  46#define pgd_present(pgd)        (1)             /* pages are always present on NO_MM */
  47#define pgd_none(pgd)           (0)
  48#define pgd_bad(pgd)            (0)
  49#define pgd_clear(pgdp)
  50#define kern_addr_valid(addr)   (1)
  51#define pmd_offset(a, b)        ((void *) 0)
  52
  53#define PAGE_NONE               __pgprot(0)     /* these mean nothing to NO_MM */
  54#define PAGE_SHARED             __pgprot(0)     /* these mean nothing to NO_MM */
  55#define PAGE_COPY               __pgprot(0)     /* these mean nothing to NO_MM */
  56#define PAGE_READONLY           __pgprot(0)     /* these mean nothing to NO_MM */
  57#define PAGE_KERNEL             __pgprot(0)     /* these mean nothing to NO_MM */
  58
  59#define __swp_type(x)           (0)
  60#define __swp_offset(x)         (0)
  61#define __swp_entry(typ,off)    ((swp_entry_t) { ((typ) | ((off) << 7)) })
  62#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
  63#define __swp_entry_to_pte(x)   ((pte_t) { (x).val })
  64
  65#define ZERO_PAGE(vaddr)        ({ BUG(); NULL; })
  66
  67#define swapper_pg_dir          ((pgd_t *) NULL)
  68
  69#define pgtable_cache_init()            do {} while (0)
  70
  71#include <asm-generic/pgtable.h>
  72
  73#else /* !CONFIG_MMU */
  74/*****************************************************************************/
  75/*
  76 * then MMU operation
  77 */
  78
  79/*
  80 * ZERO_PAGE is a global shared page that is always zero: used
  81 * for zero-mapped memory areas etc..
  82 */
  83#ifndef __ASSEMBLY__
  84extern unsigned long empty_zero_page;
  85#define ZERO_PAGE(vaddr)        virt_to_page(empty_zero_page)
  86#endif
  87
  88/*
  89 * we use 2-level page tables, folding the PMD (mid-level table) into the PGE (top-level entry)
  90 * [see Documentation/frv/mmu-layout.txt]
  91 *
  92 * Page Directory:
  93 *  - Size: 16KB
  94 *  - 64 PGEs per PGD
  95 *  - Each PGE holds 1 PUD and covers 64MB
  96 *
  97 * Page Upper Directory:
  98 *  - Size: 256B
  99 *  - 1 PUE per PUD
 100 *  - Each PUE holds 1 PMD and covers 64MB
 101 *
 102 * Page Mid-Level Directory
 103 *  - Size: 256B
 104 *  - 1 PME per PMD
 105 *  - Each PME holds 64 STEs, all of which point to separate chunks of the same Page Table
 106 *  - All STEs are instantiated at the same time
 107 *
 108 * Page Table
 109 *  - Size: 16KB
 110 *  - 4096 PTEs per PT
 111 *  - Each Linux PT is subdivided into 64 FR451 PT's, each of which holds 64 entries
 112 *
 113 * Pages
 114 *  - Size: 4KB
 115 *
 116 * total PTEs
 117 *      = 1 PML4E * 64 PGEs * 1 PUEs * 1 PMEs * 4096 PTEs
 118 *      = 1 PML4E * 64 PGEs * 64 STEs * 64 PTEs/FR451-PT
 119 *      = 262144 (or 256 * 1024)
 120 */
 121#define PGDIR_SHIFT             26
 122#define PGDIR_SIZE              (1UL << PGDIR_SHIFT)
 123#define PGDIR_MASK              (~(PGDIR_SIZE - 1))
 124#define PTRS_PER_PGD            64
 125
 126#define __PAGETABLE_PUD_FOLDED
 127#define PUD_SHIFT               26
 128#define PTRS_PER_PUD            1
 129#define PUD_SIZE                (1UL << PUD_SHIFT)
 130#define PUD_MASK                (~(PUD_SIZE - 1))
 131#define PUE_SIZE                256
 132
 133#define __PAGETABLE_PMD_FOLDED
 134#define PMD_SHIFT               26
 135#define PMD_SIZE                (1UL << PMD_SHIFT)
 136#define PMD_MASK                (~(PMD_SIZE - 1))
 137#define PTRS_PER_PMD            1
 138#define PME_SIZE                256
 139
 140#define __frv_PT_SIZE           256
 141
 142#define PTRS_PER_PTE            4096
 143
 144#define USER_PGDS_IN_LAST_PML4  (TASK_SIZE / PGDIR_SIZE)
 145#define FIRST_USER_ADDRESS      0UL
 146
 147#define USER_PGD_PTRS           (PAGE_OFFSET >> PGDIR_SHIFT)
 148#define KERNEL_PGD_PTRS         (PTRS_PER_PGD - USER_PGD_PTRS)
 149
 150#define TWOLEVEL_PGDIR_SHIFT    26
 151#define BOOT_USER_PGD_PTRS      (__PAGE_OFFSET >> TWOLEVEL_PGDIR_SHIFT)
 152#define BOOT_KERNEL_PGD_PTRS    (PTRS_PER_PGD - BOOT_USER_PGD_PTRS)
 153
 154#ifndef __ASSEMBLY__
 155
 156extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 157
 158#define pte_ERROR(e) \
 159        printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, (e).pte)
 160#define pmd_ERROR(e) \
 161        printk("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, pmd_val(e))
 162#define pud_ERROR(e) \
 163        printk("%s:%d: bad pud %08lx.\n", __FILE__, __LINE__, pmd_val(pud_val(e)))
 164#define pgd_ERROR(e) \
 165        printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pmd_val(pud_val(pgd_val(e))))
 166
 167/*
 168 * Certain architectures need to do special things when PTEs
 169 * within a page table are directly modified.  Thus, the following
 170 * hook is made available.
 171 */
 172#define set_pte(pteptr, pteval)                         \
 173do {                                                    \
 174        *(pteptr) = (pteval);                           \
 175        asm volatile("dcf %M0" :: "U"(*pteptr));        \
 176} while(0)
 177#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
 178
 179/*
 180 * pgd_offset() returns a (pgd_t *)
 181 * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
 182 */
 183#define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
 184
 185/*
 186 * a shortcut which implies the use of the kernel's pgd, instead
 187 * of a process's
 188 */
 189#define pgd_offset_k(address) pgd_offset(&init_mm, address)
 190
 191/*
 192 * The "pgd_xxx()" functions here are trivial for a folded two-level
 193 * setup: the pud is never bad, and a pud always exists (as it's folded
 194 * into the pgd entry)
 195 */
 196static inline int pgd_none(pgd_t pgd)           { return 0; }
 197static inline int pgd_bad(pgd_t pgd)            { return 0; }
 198static inline int pgd_present(pgd_t pgd)        { return 1; }
 199static inline void pgd_clear(pgd_t *pgd)        { }
 200
 201#define pgd_populate(mm, pgd, pud)              do { } while (0)
 202/*
 203 * (puds are folded into pgds so this doesn't get actually called,
 204 * but the define is needed for a generic inline function.)
 205 */
 206#define set_pgd(pgdptr, pgdval)                         \
 207do {                                                    \
 208        memcpy((pgdptr), &(pgdval), sizeof(pgd_t));     \
 209        asm volatile("dcf %M0" :: "U"(*(pgdptr)));      \
 210} while(0)
 211
 212static inline pud_t *pud_offset(pgd_t *pgd, unsigned long address)
 213{
 214        return (pud_t *) pgd;
 215}
 216
 217#define pgd_page(pgd)                           (pud_page((pud_t){ pgd }))
 218#define pgd_page_vaddr(pgd)                     (pud_page_vaddr((pud_t){ pgd }))
 219
 220/*
 221 * allocating and freeing a pud is trivial: the 1-entry pud is
 222 * inside the pgd, so has no extra memory associated with it.
 223 */
 224#define pud_alloc_one(mm, address)              NULL
 225#define pud_free(mm, x)                         do { } while (0)
 226#define __pud_free_tlb(tlb, x, address)         do { } while (0)
 227
 228/*
 229 * The "pud_xxx()" functions here are trivial for a folded two-level
 230 * setup: the pmd is never bad, and a pmd always exists (as it's folded
 231 * into the pud entry)
 232 */
 233static inline int pud_none(pud_t pud)           { return 0; }
 234static inline int pud_bad(pud_t pud)            { return 0; }
 235static inline int pud_present(pud_t pud)        { return 1; }
 236static inline void pud_clear(pud_t *pud)        { }
 237
 238#define pud_populate(mm, pmd, pte)              do { } while (0)
 239
 240/*
 241 * (pmds are folded into puds so this doesn't get actually called,
 242 * but the define is needed for a generic inline function.)
 243 */
 244#define set_pud(pudptr, pudval)                 set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
 245
 246#define pud_page(pud)                           (pmd_page((pmd_t){ pud }))
 247#define pud_page_vaddr(pud)                     (pmd_page_vaddr((pmd_t){ pud }))
 248
 249/*
 250 * (pmds are folded into pgds so this doesn't get actually called,
 251 * but the define is needed for a generic inline function.)
 252 */
 253extern void __set_pmd(pmd_t *pmdptr, unsigned long __pmd);
 254
 255#define set_pmd(pmdptr, pmdval)                 \
 256do {                                            \
 257        __set_pmd((pmdptr), (pmdval).ste[0]);   \
 258} while(0)
 259
 260#define __pmd_index(address)                    0
 261
 262static inline pmd_t *pmd_offset(pud_t *dir, unsigned long address)
 263{
 264        return (pmd_t *) dir + __pmd_index(address);
 265}
 266
 267#define pte_same(a, b)          ((a).pte == (b).pte)
 268#define pte_page(x)             (mem_map + ((unsigned long)(((x).pte >> PAGE_SHIFT))))
 269#define pte_none(x)             (!(x).pte)
 270#define pte_pfn(x)              ((unsigned long)(((x).pte >> PAGE_SHIFT)))
 271#define pfn_pte(pfn, prot)      __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
 272#define pfn_pmd(pfn, prot)      __pmd(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
 273
 274#define VMALLOC_VMADDR(x)       ((unsigned long) (x))
 275
 276#endif /* !__ASSEMBLY__ */
 277
 278/*
 279 * control flags in AMPR registers and TLB entries
 280 */
 281#define _PAGE_BIT_PRESENT       xAMPRx_V_BIT
 282#define _PAGE_BIT_WP            DAMPRx_WP_BIT
 283#define _PAGE_BIT_NOCACHE       xAMPRx_C_BIT
 284#define _PAGE_BIT_SUPER         xAMPRx_S_BIT
 285#define _PAGE_BIT_ACCESSED      xAMPRx_RESERVED8_BIT
 286#define _PAGE_BIT_DIRTY         xAMPRx_M_BIT
 287#define _PAGE_BIT_NOTGLOBAL     xAMPRx_NG_BIT
 288
 289#define _PAGE_PRESENT           xAMPRx_V
 290#define _PAGE_WP                DAMPRx_WP
 291#define _PAGE_NOCACHE           xAMPRx_C
 292#define _PAGE_SUPER             xAMPRx_S
 293#define _PAGE_ACCESSED          xAMPRx_RESERVED8        /* accessed if set */
 294#define _PAGE_DIRTY             xAMPRx_M
 295#define _PAGE_NOTGLOBAL         xAMPRx_NG
 296
 297#define _PAGE_RESERVED_MASK     (xAMPRx_RESERVED8 | xAMPRx_RESERVED13)
 298
 299#define _PAGE_PROTNONE          0x000   /* If not present */
 300
 301#define _PAGE_CHG_MASK          (PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
 302
 303#define __PGPROT_BASE \
 304        (_PAGE_PRESENT | xAMPRx_SS_16Kb | xAMPRx_D | _PAGE_NOTGLOBAL | _PAGE_ACCESSED)
 305
 306#define PAGE_NONE       __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
 307#define PAGE_SHARED     __pgprot(__PGPROT_BASE)
 308#define PAGE_COPY       __pgprot(__PGPROT_BASE | _PAGE_WP)
 309#define PAGE_READONLY   __pgprot(__PGPROT_BASE | _PAGE_WP)
 310
 311#define __PAGE_KERNEL           (__PGPROT_BASE | _PAGE_SUPER | _PAGE_DIRTY)
 312#define __PAGE_KERNEL_NOCACHE   (__PGPROT_BASE | _PAGE_SUPER | _PAGE_DIRTY | _PAGE_NOCACHE)
 313#define __PAGE_KERNEL_RO        (__PGPROT_BASE | _PAGE_SUPER | _PAGE_DIRTY | _PAGE_WP)
 314
 315#define MAKE_GLOBAL(x) __pgprot((x) & ~_PAGE_NOTGLOBAL)
 316
 317#define PAGE_KERNEL             MAKE_GLOBAL(__PAGE_KERNEL)
 318#define PAGE_KERNEL_RO          MAKE_GLOBAL(__PAGE_KERNEL_RO)
 319#define PAGE_KERNEL_NOCACHE     MAKE_GLOBAL(__PAGE_KERNEL_NOCACHE)
 320
 321#define _PAGE_TABLE             (_PAGE_PRESENT | xAMPRx_SS_16Kb)
 322
 323#ifndef __ASSEMBLY__
 324
 325/*
 326 * The FR451 can do execute protection by virtue of having separate TLB miss handlers for
 327 * instruction access and for data access. However, we don't have enough reserved bits to say
 328 * "execute only", so we don't bother. If you can read it, you can execute it and vice versa.
 329 */
 330#define __P000  PAGE_NONE
 331#define __P001  PAGE_READONLY
 332#define __P010  PAGE_COPY
 333#define __P011  PAGE_COPY
 334#define __P100  PAGE_READONLY
 335#define __P101  PAGE_READONLY
 336#define __P110  PAGE_COPY
 337#define __P111  PAGE_COPY
 338
 339#define __S000  PAGE_NONE
 340#define __S001  PAGE_READONLY
 341#define __S010  PAGE_SHARED
 342#define __S011  PAGE_SHARED
 343#define __S100  PAGE_READONLY
 344#define __S101  PAGE_READONLY
 345#define __S110  PAGE_SHARED
 346#define __S111  PAGE_SHARED
 347
 348/*
 349 * Define this to warn about kernel memory accesses that are
 350 * done without a 'access_ok(VERIFY_WRITE,..)'
 351 */
 352#undef TEST_ACCESS_OK
 353
 354#define pte_present(x)  (pte_val(x) & _PAGE_PRESENT)
 355#define pte_clear(mm,addr,xp)   do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
 356
 357#define pmd_none(x)     (!pmd_val(x))
 358#define pmd_present(x)  (pmd_val(x) & _PAGE_PRESENT)
 359#define pmd_bad(x)      (pmd_val(x) & xAMPRx_SS)
 360#define pmd_clear(xp)   do { __set_pmd(xp, 0); } while(0)
 361
 362#define pmd_page_vaddr(pmd) \
 363        ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 364
 365#ifndef CONFIG_DISCONTIGMEM
 366#define pmd_page(pmd)   (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
 367#endif
 368
 369#define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
 370
 371/*
 372 * The following only work if pte_present() is true.
 373 * Undefined behaviour if not..
 374 */
 375static inline int pte_dirty(pte_t pte)          { return (pte).pte & _PAGE_DIRTY; }
 376static inline int pte_young(pte_t pte)          { return (pte).pte & _PAGE_ACCESSED; }
 377static inline int pte_write(pte_t pte)          { return !((pte).pte & _PAGE_WP); }
 378static inline int pte_special(pte_t pte)        { return 0; }
 379
 380static inline pte_t pte_mkclean(pte_t pte)      { (pte).pte &= ~_PAGE_DIRTY; return pte; }
 381static inline pte_t pte_mkold(pte_t pte)        { (pte).pte &= ~_PAGE_ACCESSED; return pte; }
 382static inline pte_t pte_wrprotect(pte_t pte)    { (pte).pte |= _PAGE_WP; return pte; }
 383static inline pte_t pte_mkdirty(pte_t pte)      { (pte).pte |= _PAGE_DIRTY; return pte; }
 384static inline pte_t pte_mkyoung(pte_t pte)      { (pte).pte |= _PAGE_ACCESSED; return pte; }
 385static inline pte_t pte_mkwrite(pte_t pte)      { (pte).pte &= ~_PAGE_WP; return pte; }
 386static inline pte_t pte_mkspecial(pte_t pte)    { return pte; }
 387
 388static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
 389{
 390        int i = test_and_clear_bit(_PAGE_BIT_ACCESSED, ptep);
 391        asm volatile("dcf %M0" :: "U"(*ptep));
 392        return i;
 393}
 394
 395static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 396{
 397        unsigned long x = xchg(&ptep->pte, 0);
 398        asm volatile("dcf %M0" :: "U"(*ptep));
 399        return __pte(x);
 400}
 401
 402static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 403{
 404        set_bit(_PAGE_BIT_WP, ptep);
 405        asm volatile("dcf %M0" :: "U"(*ptep));
 406}
 407
 408/*
 409 * Macro to mark a page protection value as "uncacheable"
 410 */
 411#define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) | _PAGE_NOCACHE))
 412
 413/*
 414 * Conversion functions: convert a page and protection to a page entry,
 415 * and a page entry and page directory to the page they refer to.
 416 */
 417
 418#define mk_pte(page, pgprot)    pfn_pte(page_to_pfn(page), (pgprot))
 419#define mk_pte_huge(entry)      ((entry).pte_low |= _PAGE_PRESENT | _PAGE_PSE)
 420
 421/* This takes a physical page address that is used by the remapping functions */
 422#define mk_pte_phys(physpage, pgprot)   pfn_pte((physpage) >> PAGE_SHIFT, pgprot)
 423
 424static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 425{
 426        pte.pte &= _PAGE_CHG_MASK;
 427        pte.pte |= pgprot_val(newprot);
 428        return pte;
 429}
 430
 431/* to find an entry in a page-table-directory. */
 432#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 433#define pgd_index_k(addr) pgd_index(addr)
 434
 435/* Find an entry in the bottom-level page table.. */
 436#define __pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 437
 438/*
 439 * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
 440 *
 441 * this macro returns the index of the entry in the pte page which would
 442 * control the given virtual address
 443 */
 444#define pte_index(address) \
 445                (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 446#define pte_offset_kernel(dir, address) \
 447        ((pte_t *) pmd_page_vaddr(*(dir)) +  pte_index(address))
 448
 449#if defined(CONFIG_HIGHPTE)
 450#define pte_offset_map(dir, address) \
 451        ((pte_t *)kmap_atomic(pmd_page(*(dir))) + pte_index(address))
 452#define pte_unmap(pte) kunmap_atomic(pte)
 453#else
 454#define pte_offset_map(dir, address) \
 455        ((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
 456#define pte_unmap(pte) do { } while (0)
 457#endif
 458
 459/*
 460 * Handle swap and file entries
 461 * - the PTE is encoded in the following format:
 462 *      bit 0:          Must be 0 (!_PAGE_PRESENT)
 463 *      bits 1-6:       Swap type
 464 *      bits 7-31:      Swap offset
 465 */
 466#define __swp_type(x)                   (((x).val >> 1) & 0x1f)
 467#define __swp_offset(x)                 ((x).val >> 7)
 468#define __swp_entry(type, offset)       ((swp_entry_t) { ((type) << 1) | ((offset) << 7) })
 469#define __pte_to_swp_entry(_pte)        ((swp_entry_t) { (_pte).pte })
 470#define __swp_entry_to_pte(x)           ((pte_t) { (x).val })
 471
 472/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 473#define PageSkip(page)          (0)
 474#define kern_addr_valid(addr)   (1)
 475
 476#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 477#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 478#define __HAVE_ARCH_PTEP_SET_WRPROTECT
 479#define __HAVE_ARCH_PTE_SAME
 480#include <asm-generic/pgtable.h>
 481
 482/*
 483 * preload information about a newly instantiated PTE into the SCR0/SCR1 PGE cache
 484 */
 485static inline void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
 486{
 487        struct mm_struct *mm;
 488        unsigned long ampr;
 489
 490        mm = current->mm;
 491        if (mm) {
 492                pgd_t *pge = pgd_offset(mm, address);
 493                pud_t *pue = pud_offset(pge, address);
 494                pmd_t *pme = pmd_offset(pue, address);
 495
 496                ampr = pme->ste[0] & 0xffffff00;
 497                ampr |= xAMPRx_L | xAMPRx_SS_16Kb | xAMPRx_S | xAMPRx_C |
 498                        xAMPRx_V;
 499        } else {
 500                address = ULONG_MAX;
 501                ampr = 0;
 502        }
 503
 504        asm volatile("movgs %0,scr0\n"
 505                     "movgs %0,scr1\n"
 506                     "movgs %1,dampr4\n"
 507                     "movgs %1,dampr5\n"
 508                     :
 509                     : "r"(address), "r"(ampr)
 510                     );
 511}
 512
 513#ifdef CONFIG_PROC_FS
 514extern char *proc_pid_status_frv_cxnr(struct mm_struct *mm, char *buffer);
 515#endif
 516
 517extern void __init pgtable_cache_init(void);
 518
 519#endif /* !__ASSEMBLY__ */
 520#endif /* !CONFIG_MMU */
 521
 522#ifndef __ASSEMBLY__
 523extern void __init paging_init(void);
 524#endif /* !__ASSEMBLY__ */
 525
 526#endif /* _ASM_PGTABLE_H */
 527