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

   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (C) 2003 Ralf Baechle
   7 */
   8#ifndef _ASM_PGTABLE_H
   9#define _ASM_PGTABLE_H
  10
  11#include <linux/mm_types.h>
  12#include <linux/mmzone.h>
  13#ifdef CONFIG_32BIT
  14#include <asm/pgtable-32.h>
  15#endif
  16#ifdef CONFIG_64BIT
  17#include <asm/pgtable-64.h>
  18#endif
  19
  20#include <asm/io.h>
  21#include <asm/pgtable-bits.h>
  22
  23struct mm_struct;
  24struct vm_area_struct;
  25
  26#define PAGE_NONE       __pgprot(_PAGE_PRESENT | _CACHE_CACHABLE_NONCOHERENT)
  27#define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_WRITE | (cpu_has_rixi ? 0 : _PAGE_READ) | \
  28                                 _page_cachable_default)
  29#define PAGE_COPY       __pgprot(_PAGE_PRESENT | (cpu_has_rixi ? 0 : _PAGE_READ) | \
  30                                 (cpu_has_rixi ?  _PAGE_NO_EXEC : 0) | _page_cachable_default)
  31#define PAGE_READONLY   __pgprot(_PAGE_PRESENT | (cpu_has_rixi ? 0 : _PAGE_READ) | \
  32                                 _page_cachable_default)
  33#define PAGE_KERNEL     __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
  34                                 _PAGE_GLOBAL | _page_cachable_default)
  35#define PAGE_KERNEL_NC  __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
  36                                 _PAGE_GLOBAL | _CACHE_CACHABLE_NONCOHERENT)
  37#define PAGE_USERIO     __pgprot(_PAGE_PRESENT | (cpu_has_rixi ? 0 : _PAGE_READ) | _PAGE_WRITE | \
  38                                 _page_cachable_default)
  39#define PAGE_KERNEL_UNCACHED __pgprot(_PAGE_PRESENT | __READABLE | \
  40                        __WRITEABLE | _PAGE_GLOBAL | _CACHE_UNCACHED)
  41
  42/*
  43 * If _PAGE_NO_EXEC is not defined, we can't do page protection for
  44 * execute, and consider it to be the same as read. Also, write
  45 * permissions imply read permissions. This is the closest we can get
  46 * by reasonable means..
  47 */
  48
  49/*
  50 * Dummy values to fill the table in mmap.c
  51 * The real values will be generated at runtime
  52 */
  53#define __P000 __pgprot(0)
  54#define __P001 __pgprot(0)
  55#define __P010 __pgprot(0)
  56#define __P011 __pgprot(0)
  57#define __P100 __pgprot(0)
  58#define __P101 __pgprot(0)
  59#define __P110 __pgprot(0)
  60#define __P111 __pgprot(0)
  61
  62#define __S000 __pgprot(0)
  63#define __S001 __pgprot(0)
  64#define __S010 __pgprot(0)
  65#define __S011 __pgprot(0)
  66#define __S100 __pgprot(0)
  67#define __S101 __pgprot(0)
  68#define __S110 __pgprot(0)
  69#define __S111 __pgprot(0)
  70
  71extern unsigned long _page_cachable_default;
  72
  73/*
  74 * ZERO_PAGE is a global shared page that is always zero; used
  75 * for zero-mapped memory areas etc..
  76 */
  77
  78extern unsigned long empty_zero_page;
  79extern unsigned long zero_page_mask;
  80
  81#define ZERO_PAGE(vaddr) \
  82        (virt_to_page((void *)(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask))))
  83#define __HAVE_COLOR_ZERO_PAGE
  84
  85extern void paging_init(void);
  86
  87/*
  88 * Conversion functions: convert a page and protection to a page entry,
  89 * and a page entry and page directory to the page they refer to.
  90 */
  91#define pmd_phys(pmd)           virt_to_phys((void *)pmd_val(pmd))
  92
  93#define __pmd_page(pmd)         (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
  94#ifndef CONFIG_TRANSPARENT_HUGEPAGE
  95#define pmd_page(pmd)           __pmd_page(pmd)
  96#endif /* CONFIG_TRANSPARENT_HUGEPAGE  */
  97
  98#define pmd_page_vaddr(pmd)     pmd_val(pmd)
  99
 100#define htw_stop()                                                      \
 101do {                                                                    \
 102        if (cpu_has_htw)                                                \
 103                write_c0_pwctl(read_c0_pwctl() &                        \
 104                               ~(1 << MIPS_PWCTL_PWEN_SHIFT));          \
 105} while(0)
 106
 107#define htw_start()                                                     \
 108do {                                                                    \
 109        if (cpu_has_htw)                                                \
 110                write_c0_pwctl(read_c0_pwctl() |                        \
 111                               (1 << MIPS_PWCTL_PWEN_SHIFT));           \
 112} while(0)
 113
 114
 115#define htw_reset()                                                     \
 116do {                                                                    \
 117        if (cpu_has_htw) {                                              \
 118                htw_stop();                                             \
 119                back_to_back_c0_hazard();                               \
 120                htw_start();                                            \
 121                back_to_back_c0_hazard();                               \
 122        }                                                               \
 123} while(0)
 124
 125extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 126        pte_t pteval);
 127
 128#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 129
 130#define pte_none(pte)           (!(((pte).pte_low | (pte).pte_high) & ~_PAGE_GLOBAL))
 131#define pte_present(pte)        ((pte).pte_low & _PAGE_PRESENT)
 132
 133static inline void set_pte(pte_t *ptep, pte_t pte)
 134{
 135        ptep->pte_high = pte.pte_high;
 136        smp_wmb();
 137        ptep->pte_low = pte.pte_low;
 138
 139        if (pte.pte_low & _PAGE_GLOBAL) {
 140                pte_t *buddy = ptep_buddy(ptep);
 141                /*
 142                 * Make sure the buddy is global too (if it's !none,
 143                 * it better already be global)
 144                 */
 145                if (pte_none(*buddy)) {
 146                        buddy->pte_low  |= _PAGE_GLOBAL;
 147                        buddy->pte_high |= _PAGE_GLOBAL;
 148                }
 149        }
 150}
 151
 152static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 153{
 154        pte_t null = __pte(0);
 155
 156        /* Preserve global status for the pair */
 157        if (ptep_buddy(ptep)->pte_low & _PAGE_GLOBAL)
 158                null.pte_low = null.pte_high = _PAGE_GLOBAL;
 159
 160        set_pte_at(mm, addr, ptep, null);
 161        htw_reset();
 162}
 163#else
 164
 165#define pte_none(pte)           (!(pte_val(pte) & ~_PAGE_GLOBAL))
 166#define pte_present(pte)        (pte_val(pte) & _PAGE_PRESENT)
 167
 168/*
 169 * Certain architectures need to do special things when pte's
 170 * within a page table are directly modified.  Thus, the following
 171 * hook is made available.
 172 */
 173static inline void set_pte(pte_t *ptep, pte_t pteval)
 174{
 175        *ptep = pteval;
 176#if !defined(CONFIG_CPU_R3000) && !defined(CONFIG_CPU_TX39XX)
 177        if (pte_val(pteval) & _PAGE_GLOBAL) {
 178                pte_t *buddy = ptep_buddy(ptep);
 179                /*
 180                 * Make sure the buddy is global too (if it's !none,
 181                 * it better already be global)
 182                 */
 183                if (pte_none(*buddy))
 184                        pte_val(*buddy) = pte_val(*buddy) | _PAGE_GLOBAL;
 185        }
 186#endif
 187}
 188
 189static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 190{
 191#if !defined(CONFIG_CPU_R3000) && !defined(CONFIG_CPU_TX39XX)
 192        /* Preserve global status for the pair */
 193        if (pte_val(*ptep_buddy(ptep)) & _PAGE_GLOBAL)
 194                set_pte_at(mm, addr, ptep, __pte(_PAGE_GLOBAL));
 195        else
 196#endif
 197                set_pte_at(mm, addr, ptep, __pte(0));
 198        htw_reset();
 199}
 200#endif
 201
 202/*
 203 * (pmds are folded into puds so this doesn't get actually called,
 204 * but the define is needed for a generic inline function.)
 205 */
 206#define set_pmd(pmdptr, pmdval) do { *(pmdptr) = (pmdval); } while(0)
 207
 208#ifndef __PAGETABLE_PMD_FOLDED
 209/*
 210 * (puds are folded into pgds so this doesn't get actually called,
 211 * but the define is needed for a generic inline function.)
 212 */
 213#define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while(0)
 214#endif
 215
 216#define PGD_T_LOG2      (__builtin_ffs(sizeof(pgd_t)) - 1)
 217#define PMD_T_LOG2      (__builtin_ffs(sizeof(pmd_t)) - 1)
 218#define PTE_T_LOG2      (__builtin_ffs(sizeof(pte_t)) - 1)
 219
 220/*
 221 * We used to declare this array with size but gcc 3.3 and older are not able
 222 * to find that this expression is a constant, so the size is dropped.
 223 */
 224extern pgd_t swapper_pg_dir[];
 225
 226/*
 227 * The following only work if pte_present() is true.
 228 * Undefined behaviour if not..
 229 */
 230#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 231static inline int pte_write(pte_t pte)  { return pte.pte_low & _PAGE_WRITE; }
 232static inline int pte_dirty(pte_t pte)  { return pte.pte_low & _PAGE_MODIFIED; }
 233static inline int pte_young(pte_t pte)  { return pte.pte_low & _PAGE_ACCESSED; }
 234static inline int pte_file(pte_t pte)   { return pte.pte_low & _PAGE_FILE; }
 235
 236static inline pte_t pte_wrprotect(pte_t pte)
 237{
 238        pte.pte_low  &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
 239        pte.pte_high &= ~_PAGE_SILENT_WRITE;
 240        return pte;
 241}
 242
 243static inline pte_t pte_mkclean(pte_t pte)
 244{
 245        pte.pte_low  &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
 246        pte.pte_high &= ~_PAGE_SILENT_WRITE;
 247        return pte;
 248}
 249
 250static inline pte_t pte_mkold(pte_t pte)
 251{
 252        pte.pte_low  &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ);
 253        pte.pte_high &= ~_PAGE_SILENT_READ;
 254        return pte;
 255}
 256
 257static inline pte_t pte_mkwrite(pte_t pte)
 258{
 259        pte.pte_low |= _PAGE_WRITE;
 260        if (pte.pte_low & _PAGE_MODIFIED) {
 261                pte.pte_low  |= _PAGE_SILENT_WRITE;
 262                pte.pte_high |= _PAGE_SILENT_WRITE;
 263        }
 264        return pte;
 265}
 266
 267static inline pte_t pte_mkdirty(pte_t pte)
 268{
 269        pte.pte_low |= _PAGE_MODIFIED;
 270        if (pte.pte_low & _PAGE_WRITE) {
 271                pte.pte_low  |= _PAGE_SILENT_WRITE;
 272                pte.pte_high |= _PAGE_SILENT_WRITE;
 273        }
 274        return pte;
 275}
 276
 277static inline pte_t pte_mkyoung(pte_t pte)
 278{
 279        pte.pte_low |= _PAGE_ACCESSED;
 280        if (pte.pte_low & _PAGE_READ) {
 281                pte.pte_low  |= _PAGE_SILENT_READ;
 282                pte.pte_high |= _PAGE_SILENT_READ;
 283        }
 284        return pte;
 285}
 286#else
 287static inline int pte_write(pte_t pte)  { return pte_val(pte) & _PAGE_WRITE; }
 288static inline int pte_dirty(pte_t pte)  { return pte_val(pte) & _PAGE_MODIFIED; }
 289static inline int pte_young(pte_t pte)  { return pte_val(pte) & _PAGE_ACCESSED; }
 290static inline int pte_file(pte_t pte)   { return pte_val(pte) & _PAGE_FILE; }
 291
 292static inline pte_t pte_wrprotect(pte_t pte)
 293{
 294        pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
 295        return pte;
 296}
 297
 298static inline pte_t pte_mkclean(pte_t pte)
 299{
 300        pte_val(pte) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
 301        return pte;
 302}
 303
 304static inline pte_t pte_mkold(pte_t pte)
 305{
 306        pte_val(pte) &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ);
 307        return pte;
 308}
 309
 310static inline pte_t pte_mkwrite(pte_t pte)
 311{
 312        pte_val(pte) |= _PAGE_WRITE;
 313        if (pte_val(pte) & _PAGE_MODIFIED)
 314                pte_val(pte) |= _PAGE_SILENT_WRITE;
 315        return pte;
 316}
 317
 318static inline pte_t pte_mkdirty(pte_t pte)
 319{
 320        pte_val(pte) |= _PAGE_MODIFIED;
 321        if (pte_val(pte) & _PAGE_WRITE)
 322                pte_val(pte) |= _PAGE_SILENT_WRITE;
 323        return pte;
 324}
 325
 326static inline pte_t pte_mkyoung(pte_t pte)
 327{
 328        pte_val(pte) |= _PAGE_ACCESSED;
 329        if (cpu_has_rixi) {
 330                if (!(pte_val(pte) & _PAGE_NO_READ))
 331                        pte_val(pte) |= _PAGE_SILENT_READ;
 332        } else {
 333                if (pte_val(pte) & _PAGE_READ)
 334                        pte_val(pte) |= _PAGE_SILENT_READ;
 335        }
 336        return pte;
 337}
 338
 339#ifdef _PAGE_HUGE
 340static inline int pte_huge(pte_t pte)   { return pte_val(pte) & _PAGE_HUGE; }
 341
 342static inline pte_t pte_mkhuge(pte_t pte)
 343{
 344        pte_val(pte) |= _PAGE_HUGE;
 345        return pte;
 346}
 347#endif /* _PAGE_HUGE */
 348#endif
 349static inline int pte_special(pte_t pte)        { return 0; }
 350static inline pte_t pte_mkspecial(pte_t pte)    { return pte; }
 351
 352/*
 353 * Macro to make mark a page protection value as "uncacheable".  Note
 354 * that "protection" is really a misnomer here as the protection value
 355 * contains the memory attribute bits, dirty bits, and various other
 356 * bits as well.
 357 */
 358#define pgprot_noncached pgprot_noncached
 359
 360static inline pgprot_t pgprot_noncached(pgprot_t _prot)
 361{
 362        unsigned long prot = pgprot_val(_prot);
 363
 364        prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED;
 365
 366        return __pgprot(prot);
 367}
 368
 369static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
 370{
 371        unsigned long prot = pgprot_val(_prot);
 372
 373        /* cpu_data[0].writecombine is already shifted by _CACHE_SHIFT */
 374        prot = (prot & ~_CACHE_MASK) | cpu_data[0].writecombine;
 375
 376        return __pgprot(prot);
 377}
 378
 379/*
 380 * Conversion functions: convert a page and protection to a page entry,
 381 * and a page entry and page directory to the page they refer to.
 382 */
 383#define mk_pte(page, pgprot)    pfn_pte(page_to_pfn(page), (pgprot))
 384
 385#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 386static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 387{
 388        pte.pte_low  &= _PAGE_CHG_MASK;
 389        pte.pte_high &= (_PFN_MASK | _CACHE_MASK);
 390        pte.pte_low  |= pgprot_val(newprot);
 391        pte.pte_high |= pgprot_val(newprot) & ~(_PFN_MASK | _CACHE_MASK);
 392        return pte;
 393}
 394#else
 395static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 396{
 397        return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
 398}
 399#endif
 400
 401
 402extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,
 403        pte_t pte);
 404
 405static inline void update_mmu_cache(struct vm_area_struct *vma,
 406        unsigned long address, pte_t *ptep)
 407{
 408        pte_t pte = *ptep;
 409        __update_tlb(vma, address, pte);
 410}
 411
 412static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
 413        unsigned long address, pmd_t *pmdp)
 414{
 415        pte_t pte = *(pte_t *)pmdp;
 416
 417        __update_tlb(vma, address, pte);
 418}
 419
 420#define kern_addr_valid(addr)   (1)
 421
 422#ifdef CONFIG_PHYS_ADDR_T_64BIT
 423extern int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot);
 424
 425static inline int io_remap_pfn_range(struct vm_area_struct *vma,
 426                unsigned long vaddr,
 427                unsigned long pfn,
 428                unsigned long size,
 429                pgprot_t prot)
 430{
 431        phys_addr_t phys_addr_high = fixup_bigphys_addr(pfn << PAGE_SHIFT, size);
 432        return remap_pfn_range(vma, vaddr, phys_addr_high >> PAGE_SHIFT, size, prot);
 433}
 434#define io_remap_pfn_range io_remap_pfn_range
 435#endif
 436
 437#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 438
 439extern int has_transparent_hugepage(void);
 440
 441static inline int pmd_trans_huge(pmd_t pmd)
 442{
 443        return !!(pmd_val(pmd) & _PAGE_HUGE);
 444}
 445
 446static inline pmd_t pmd_mkhuge(pmd_t pmd)
 447{
 448        pmd_val(pmd) |= _PAGE_HUGE;
 449
 450        return pmd;
 451}
 452
 453static inline int pmd_trans_splitting(pmd_t pmd)
 454{
 455        return !!(pmd_val(pmd) & _PAGE_SPLITTING);
 456}
 457
 458static inline pmd_t pmd_mksplitting(pmd_t pmd)
 459{
 460        pmd_val(pmd) |= _PAGE_SPLITTING;
 461
 462        return pmd;
 463}
 464
 465extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 466                       pmd_t *pmdp, pmd_t pmd);
 467
 468#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
 469/* Extern to avoid header file madness */
 470extern void pmdp_splitting_flush(struct vm_area_struct *vma,
 471                                        unsigned long address,
 472                                        pmd_t *pmdp);
 473
 474#define __HAVE_ARCH_PMD_WRITE
 475static inline int pmd_write(pmd_t pmd)
 476{
 477        return !!(pmd_val(pmd) & _PAGE_WRITE);
 478}
 479
 480static inline pmd_t pmd_wrprotect(pmd_t pmd)
 481{
 482        pmd_val(pmd) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
 483        return pmd;
 484}
 485
 486static inline pmd_t pmd_mkwrite(pmd_t pmd)
 487{
 488        pmd_val(pmd) |= _PAGE_WRITE;
 489        if (pmd_val(pmd) & _PAGE_MODIFIED)
 490                pmd_val(pmd) |= _PAGE_SILENT_WRITE;
 491
 492        return pmd;
 493}
 494
 495static inline int pmd_dirty(pmd_t pmd)
 496{
 497        return !!(pmd_val(pmd) & _PAGE_MODIFIED);
 498}
 499
 500static inline pmd_t pmd_mkclean(pmd_t pmd)
 501{
 502        pmd_val(pmd) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
 503        return pmd;
 504}
 505
 506static inline pmd_t pmd_mkdirty(pmd_t pmd)
 507{
 508        pmd_val(pmd) |= _PAGE_MODIFIED;
 509        if (pmd_val(pmd) & _PAGE_WRITE)
 510                pmd_val(pmd) |= _PAGE_SILENT_WRITE;
 511
 512        return pmd;
 513}
 514
 515static inline int pmd_young(pmd_t pmd)
 516{
 517        return !!(pmd_val(pmd) & _PAGE_ACCESSED);
 518}
 519
 520static inline pmd_t pmd_mkold(pmd_t pmd)
 521{
 522        pmd_val(pmd) &= ~(_PAGE_ACCESSED|_PAGE_SILENT_READ);
 523
 524        return pmd;
 525}
 526
 527static inline pmd_t pmd_mkyoung(pmd_t pmd)
 528{
 529        pmd_val(pmd) |= _PAGE_ACCESSED;
 530
 531        if (cpu_has_rixi) {
 532                if (!(pmd_val(pmd) & _PAGE_NO_READ))
 533                        pmd_val(pmd) |= _PAGE_SILENT_READ;
 534        } else {
 535                if (pmd_val(pmd) & _PAGE_READ)
 536                        pmd_val(pmd) |= _PAGE_SILENT_READ;
 537        }
 538
 539        return pmd;
 540}
 541
 542/* Extern to avoid header file madness */
 543extern pmd_t mk_pmd(struct page *page, pgprot_t prot);
 544
 545static inline unsigned long pmd_pfn(pmd_t pmd)
 546{
 547        return pmd_val(pmd) >> _PFN_SHIFT;
 548}
 549
 550static inline struct page *pmd_page(pmd_t pmd)
 551{
 552        if (pmd_trans_huge(pmd))
 553                return pfn_to_page(pmd_pfn(pmd));
 554
 555        return pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT);
 556}
 557
 558static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
 559{
 560        pmd_val(pmd) = (pmd_val(pmd) & _PAGE_CHG_MASK) | pgprot_val(newprot);
 561        return pmd;
 562}
 563
 564static inline pmd_t pmd_mknotpresent(pmd_t pmd)
 565{
 566        pmd_val(pmd) &= ~(_PAGE_PRESENT | _PAGE_VALID | _PAGE_DIRTY);
 567
 568        return pmd;
 569}
 570
 571/*
 572 * The generic version pmdp_get_and_clear uses a version of pmd_clear() with a
 573 * different prototype.
 574 */
 575#define __HAVE_ARCH_PMDP_GET_AND_CLEAR
 576static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
 577                                       unsigned long address, pmd_t *pmdp)
 578{
 579        pmd_t old = *pmdp;
 580
 581        pmd_clear(pmdp);
 582
 583        return old;
 584}
 585
 586#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 587
 588#include <asm-generic/pgtable.h>
 589
 590/*
 591 * uncached accelerated TLB map for video memory access
 592 */
 593#ifdef CONFIG_CPU_SUPPORTS_UNCACHED_ACCELERATED
 594#define __HAVE_PHYS_MEM_ACCESS_PROT
 595
 596struct file;
 597pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 598                unsigned long size, pgprot_t vma_prot);
 599int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
 600                unsigned long size, pgprot_t *vma_prot);
 601#endif
 602
 603/*
 604 * We provide our own get_unmapped area to cope with the virtual aliasing
 605 * constraints placed on us by the cache architecture.
 606 */
 607#define HAVE_ARCH_UNMAPPED_AREA
 608#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 609
 610/*
 611 * No page table caches to initialise
 612 */
 613#define pgtable_cache_init()    do { } while (0)
 614
 615#endif /* _ASM_PGTABLE_H */
 616