include/asm-ia64/pgtable.h

   1 #ifndef _ASM_IA64_PGTABLE_H
   2 #define _ASM_IA64_PGTABLE_H
   3
   4 /*
   5  * This file contains the functions and defines necessary to modify and use
   6  * the IA-64 page table tree.
   7  *
   8  * This hopefully works with any (fixed) IA-64 page-size, as defined
   9  * in <asm/page.h>.
  10  *
  11  * Copyright (C) 1998-2005 Hewlett-Packard Co
  12  *      David Mosberger-Tang <davidm@hpl.hp.com>
  13  */
  14
  15
  16 #include <asm/mman.h>
  17 #include <asm/page.h>
  18 #include <asm/processor.h>
  19 #include <asm/system.h>
  20 #include <asm/types.h>
  21
  22 #define IA64_MAX_PHYS_BITS      50      /* max. number of physical address bits (architected) */
  23
  24 /*
  25  * First, define the various bits in a PTE.  Note that the PTE format
  26  * matches the VHPT short format, the firt doubleword of the VHPD long
  27  * format, and the first doubleword of the TLB insertion format.
  28  */
  29 #define _PAGE_P_BIT             0
  30 #define _PAGE_A_BIT             5
  31 #define _PAGE_D_BIT             6
  32
  33 #define _PAGE_P                 (1 << _PAGE_P_BIT)      /* page present bit */
  34 #define _PAGE_MA_WB             (0x0 <<  2)     /* write back memory attribute */
  35 #define _PAGE_MA_UC             (0x4 <<  2)     /* uncacheable memory attribute */
  36 #define _PAGE_MA_UCE            (0x5 <<  2)     /* UC exported attribute */
  37 #define _PAGE_MA_WC             (0x6 <<  2)     /* write coalescing memory attribute */
  38 #define _PAGE_MA_NAT            (0x7 <<  2)     /* not-a-thing attribute */
  39 #define _PAGE_MA_MASK           (0x7 <<  2)
  40 #define _PAGE_PL_0              (0 <<  7)       /* privilege level 0 (kernel) */
  41 #define _PAGE_PL_1              (1 <<  7)       /* privilege level 1 (unused) */
  42 #define _PAGE_PL_2              (2 <<  7)       /* privilege level 2 (unused) */
  43 #define _PAGE_PL_3              (3 <<  7)       /* privilege level 3 (user) */
  44 #define _PAGE_PL_MASK           (3 <<  7)
  45 #define _PAGE_AR_R              (0 <<  9)       /* read only */
  46 #define _PAGE_AR_RX             (1 <<  9)       /* read & execute */
  47 #define _PAGE_AR_RW             (2 <<  9)       /* read & write */
  48 #define _PAGE_AR_RWX            (3 <<  9)       /* read, write & execute */
  49 #define _PAGE_AR_R_RW           (4 <<  9)       /* read / read & write */
  50 #define _PAGE_AR_RX_RWX         (5 <<  9)       /* read & exec / read, write & exec */
  51 #define _PAGE_AR_RWX_RW         (6 <<  9)       /* read, write & exec / read & write */
  52 #define _PAGE_AR_X_RX           (7 <<  9)       /* exec & promote / read & exec */
  53 #define _PAGE_AR_MASK           (7 <<  9)
  54 #define _PAGE_AR_SHIFT          9
  55 #define _PAGE_A                 (1 << _PAGE_A_BIT)      /* page accessed bit */
  56 #define _PAGE_D                 (1 << _PAGE_D_BIT)      /* page dirty bit */
  57 #define _PAGE_PPN_MASK          (((__IA64_UL(1) << IA64_MAX_PHYS_BITS) - 1) & ~0xfffUL)
  58 #define _PAGE_ED                (__IA64_UL(1) << 52)    /* exception deferral */
  59 #define _PAGE_PROTNONE          (__IA64_UL(1) << 63)
  60
  61 /* Valid only for a PTE with the present bit cleared: */
  62 #define _PAGE_FILE              (1 << 1)                /* see swap & file pte remarks below */
  63
  64 #define _PFN_MASK               _PAGE_PPN_MASK
  65 /* Mask of bits which may be changed by pte_modify(); the odd bits are there for _PAGE_PROTNONE */
  66 #define _PAGE_CHG_MASK  (_PAGE_P | _PAGE_PROTNONE | _PAGE_PL_MASK | _PAGE_AR_MASK | _PAGE_ED)
  67
  68 #define _PAGE_SIZE_4K   12
  69 #define _PAGE_SIZE_8K   13
  70 #define _PAGE_SIZE_16K  14
  71 #define _PAGE_SIZE_64K  16
  72 #define _PAGE_SIZE_256K 18
  73 #define _PAGE_SIZE_1M   20
  74 #define _PAGE_SIZE_4M   22
  75 #define _PAGE_SIZE_16M  24
  76 #define _PAGE_SIZE_64M  26
  77 #define _PAGE_SIZE_256M 28
  78 #define _PAGE_SIZE_1G   30
  79 #define _PAGE_SIZE_4G   32
  80
  81 #define __ACCESS_BITS           _PAGE_ED | _PAGE_A | _PAGE_P | _PAGE_MA_WB
  82 #define __DIRTY_BITS_NO_ED      _PAGE_A | _PAGE_P | _PAGE_D | _PAGE_MA_WB
  83 #define __DIRTY_BITS            _PAGE_ED | __DIRTY_BITS_NO_ED
  84
  85 /*
  86  * How many pointers will a page table level hold expressed in shift
  87  */
  88 #define PTRS_PER_PTD_SHIFT      (PAGE_SHIFT-3)
  89
  90 /*
  91  * Definitions for fourth level:
  92  */
  93 #define PTRS_PER_PTE    (__IA64_UL(1) << (PTRS_PER_PTD_SHIFT))
  94
  95 /*
  96  * Definitions for third level:
  97  *
  98  * PMD_SHIFT determines the size of the area a third-level page table
  99  * can map.
 100  */
 101 #define PMD_SHIFT       (PAGE_SHIFT + (PTRS_PER_PTD_SHIFT))
 102 #define PMD_SIZE        (1UL << PMD_SHIFT)
 103 #define PMD_MASK        (~(PMD_SIZE-1))
 104 #define PTRS_PER_PMD    (1UL << (PTRS_PER_PTD_SHIFT))
 105
 106 #ifdef CONFIG_PGTABLE_4
 107 /*
 108  * Definitions for second level:
 109  *
 110  * PUD_SHIFT determines the size of the area a second-level page table
 111  * can map.
 112  */
 113 #define PUD_SHIFT       (PMD_SHIFT + (PTRS_PER_PTD_SHIFT))
 114 #define PUD_SIZE        (1UL << PUD_SHIFT)
 115 #define PUD_MASK        (~(PUD_SIZE-1))
 116 #define PTRS_PER_PUD    (1UL << (PTRS_PER_PTD_SHIFT))
 117 #endif
 118
 119 /*
 120  * Definitions for first level:
 121  *
 122  * PGDIR_SHIFT determines what a first-level page table entry can map.
 123  */
 124 #ifdef CONFIG_PGTABLE_4
 125 #define PGDIR_SHIFT             (PUD_SHIFT + (PTRS_PER_PTD_SHIFT))
 126 #else
 127 #define PGDIR_SHIFT             (PMD_SHIFT + (PTRS_PER_PTD_SHIFT))
 128 #endif
 129 #define PGDIR_SIZE              (__IA64_UL(1) << PGDIR_SHIFT)
 130 #define PGDIR_MASK              (~(PGDIR_SIZE-1))
 131 #define PTRS_PER_PGD_SHIFT      PTRS_PER_PTD_SHIFT
 132 #define PTRS_PER_PGD            (1UL << PTRS_PER_PGD_SHIFT)
 133 #define USER_PTRS_PER_PGD       (5*PTRS_PER_PGD/8)      /* regions 0-4 are user regions */
 134 #define FIRST_USER_ADDRESS      0
 135
 136 /*
 137  * All the normal masks have the "page accessed" bits on, as any time
 138  * they are used, the page is accessed. They are cleared only by the
 139  * page-out routines.
 140  */
 141 #define PAGE_NONE       __pgprot(_PAGE_PROTNONE | _PAGE_A)
 142 #define PAGE_SHARED     __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RW)
 143 #define PAGE_READONLY   __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
 144 #define PAGE_COPY       __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
 145 #define PAGE_COPY_EXEC  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
 146 #define PAGE_GATE       __pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_X_RX)
 147 #define PAGE_KERNEL     __pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX)
 148 #define PAGE_KERNELRX   __pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_RX)
 149
 150 # ifndef __ASSEMBLY__
 151
 152 #include <linux/sched.h>        /* for mm_struct */
 153 #include <asm/bitops.h>
 154 #include <asm/cacheflush.h>
 155 #include <asm/mmu_context.h>
 156 #include <asm/processor.h>
 157
 158 /*
 159  * Next come the mappings that determine how mmap() protection bits
 160  * (PROT_EXEC, PROT_READ, PROT_WRITE, PROT_NONE) get implemented.  The
 161  * _P version gets used for a private shared memory segment, the _S
 162  * version gets used for a shared memory segment with MAP_SHARED on.
 163  * In a private shared memory segment, we do a copy-on-write if a task
 164  * attempts to write to the page.
 165  */
 166         /* xwr */
 167 #define __P000  PAGE_NONE
 168 #define __P001  PAGE_READONLY
 169 #define __P010  PAGE_READONLY   /* write to priv pg -> copy & make writable */
 170 #define __P011  PAGE_READONLY   /* ditto */
 171 #define __P100  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
 172 #define __P101  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
 173 #define __P110  PAGE_COPY_EXEC
 174 #define __P111  PAGE_COPY_EXEC
 175
 176 #define __S000  PAGE_NONE
 177 #define __S001  PAGE_READONLY
 178 #define __S010  PAGE_SHARED     /* we don't have (and don't need) write-only */
 179 #define __S011  PAGE_SHARED
 180 #define __S100  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
 181 #define __S101  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
 182 #define __S110  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
 183 #define __S111  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
 184
 185 #define pgd_ERROR(e)    printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
 186 #ifdef CONFIG_PGTABLE_4
 187 #define pud_ERROR(e)    printk("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
 188 #endif
 189 #define pmd_ERROR(e)    printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
 190 #define pte_ERROR(e)    printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
 191
 192
 193 /*
 194  * Some definitions to translate between mem_map, PTEs, and page addresses:
 195  */
 196
 197
 198 /* Quick test to see if ADDR is a (potentially) valid physical address. */
 199 static inline long
 200 ia64_phys_addr_valid (unsigned long addr)
 201 {
 202         return (addr & (local_cpu_data->unimpl_pa_mask)) == 0;
 203 }
 204
 205 /*
 206  * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
 207  * memory.  For the return value to be meaningful, ADDR must be >=
 208  * PAGE_OFFSET.  This operation can be relatively expensive (e.g.,
 209  * require a hash-, or multi-level tree-lookup or something of that
 210  * sort) but it guarantees to return TRUE only if accessing the page
 211  * at that address does not cause an error.  Note that there may be
 212  * addresses for which kern_addr_valid() returns FALSE even though an
 213  * access would not cause an error (e.g., this is typically true for
 214  * memory mapped I/O regions.
 215  *
 216  * XXX Need to implement this for IA-64.
 217  */
 218 #define kern_addr_valid(addr)   (1)
 219
 220
 221 /*
 222  * Now come the defines and routines to manage and access the three-level
 223  * page table.
 224  */
 225
 226 /*
 227  * On some architectures, special things need to be done when setting
 228  * the PTE in a page table.  Nothing special needs to be on IA-64.
 229  */
 230 #define set_pte(ptep, pteval)   (*(ptep) = (pteval))
 231 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
 232
 233 #define VMALLOC_START           (RGN_BASE(RGN_GATE) + 0x200000000UL)
 234 #ifdef CONFIG_VIRTUAL_MEM_MAP
 235 # define VMALLOC_END_INIT       (RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
 236 # define VMALLOC_END            vmalloc_end
 237   extern unsigned long vmalloc_end;
 238 #else
 239 # define VMALLOC_END            (RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
 240 #endif
 241
 242 /* fs/proc/kcore.c */
 243 #define kc_vaddr_to_offset(v) ((v) - RGN_BASE(RGN_GATE))
 244 #define kc_offset_to_vaddr(o) ((o) + RGN_BASE(RGN_GATE))
 245
 246 #define RGN_MAP_SHIFT (PGDIR_SHIFT + PTRS_PER_PGD_SHIFT - 3)
 247 #define RGN_MAP_LIMIT   ((1UL << RGN_MAP_SHIFT) - PAGE_SIZE)    /* per region addr limit */
 248
 249 /*
 250  * Conversion functions: convert page frame number (pfn) and a protection value to a page
 251  * table entry (pte).
 252  */
 253 #define pfn_pte(pfn, pgprot) \
 254 ({ pte_t __pte; pte_val(__pte) = ((pfn) << PAGE_SHIFT) | pgprot_val(pgprot); __pte; })
 255
 256 /* Extract pfn from pte.  */
 257 #define pte_pfn(_pte)           ((pte_val(_pte) & _PFN_MASK) >> PAGE_SHIFT)
 258
 259 #define mk_pte(page, pgprot)    pfn_pte(page_to_pfn(page), (pgprot))
 260
 261 /* This takes a physical page address that is used by the remapping functions */
 262 #define mk_pte_phys(physpage, pgprot) \
 263 ({ pte_t __pte; pte_val(__pte) = physpage + pgprot_val(pgprot); __pte; })
 264
 265 #define pte_modify(_pte, newprot) \
 266         (__pte((pte_val(_pte) & ~_PAGE_CHG_MASK) | (pgprot_val(newprot) & _PAGE_CHG_MASK)))
 267
 268 #define pte_none(pte)                   (!pte_val(pte))
 269 #define pte_present(pte)                (pte_val(pte) & (_PAGE_P | _PAGE_PROTNONE))
 270 #define pte_clear(mm,addr,pte)          (pte_val(*(pte)) = 0UL)
 271 /* pte_page() returns the "struct page *" corresponding to the PTE: */
 272 #define pte_page(pte)                   virt_to_page(((pte_val(pte) & _PFN_MASK) + PAGE_OFFSET))
 273
 274 #define pmd_none(pmd)                   (!pmd_val(pmd))
 275 #define pmd_bad(pmd)                    (!ia64_phys_addr_valid(pmd_val(pmd)))
 276 #define pmd_present(pmd)                (pmd_val(pmd) != 0UL)
 277 #define pmd_clear(pmdp)                 (pmd_val(*(pmdp)) = 0UL)
 278 #define pmd_page_kernel(pmd)            ((unsigned long) __va(pmd_val(pmd) & _PFN_MASK))
 279 #define pmd_page(pmd)                   virt_to_page((pmd_val(pmd) + PAGE_OFFSET))
 280
 281 #define pud_none(pud)                   (!pud_val(pud))
 282 #define pud_bad(pud)                    (!ia64_phys_addr_valid(pud_val(pud)))
 283 #define pud_present(pud)                (pud_val(pud) != 0UL)
 284 #define pud_clear(pudp)                 (pud_val(*(pudp)) = 0UL)
 285 #define pud_page(pud)                   ((unsigned long) __va(pud_val(pud) & _PFN_MASK))
 286
 287 #ifdef CONFIG_PGTABLE_4
 288 #define pgd_none(pgd)                   (!pgd_val(pgd))
 289 #define pgd_bad(pgd)                    (!ia64_phys_addr_valid(pgd_val(pgd)))
 290 #define pgd_present(pgd)                (pgd_val(pgd) != 0UL)
 291 #define pgd_clear(pgdp)                 (pgd_val(*(pgdp)) = 0UL)
 292 #define pgd_page(pgd)                   ((unsigned long) __va(pgd_val(pgd) & _PFN_MASK))
 293 #endif
 294
 295 /*
 296  * The following have defined behavior only work if pte_present() is true.
 297  */
 298 #define pte_user(pte)           ((pte_val(pte) & _PAGE_PL_MASK) == _PAGE_PL_3)
 299 #define pte_read(pte)           (((pte_val(pte) & _PAGE_AR_MASK) >> _PAGE_AR_SHIFT) < 6)
 300 #define pte_write(pte)  ((unsigned) (((pte_val(pte) & _PAGE_AR_MASK) >> _PAGE_AR_SHIFT) - 2) <= 4)
 301 #define pte_exec(pte)           ((pte_val(pte) & _PAGE_AR_RX) != 0)
 302 #define pte_dirty(pte)          ((pte_val(pte) & _PAGE_D) != 0)
 303 #define pte_young(pte)          ((pte_val(pte) & _PAGE_A) != 0)
 304 #define pte_file(pte)           ((pte_val(pte) & _PAGE_FILE) != 0)
 305 /*
 306  * Note: we convert AR_RWX to AR_RX and AR_RW to AR_R by clearing the 2nd bit in the
 307  * access rights:
 308  */
 309 #define pte_wrprotect(pte)      (__pte(pte_val(pte) & ~_PAGE_AR_RW))
 310 #define pte_mkwrite(pte)        (__pte(pte_val(pte) | _PAGE_AR_RW))
 311 #define pte_mkexec(pte)         (__pte(pte_val(pte) | _PAGE_AR_RX))
 312 #define pte_mkold(pte)          (__pte(pte_val(pte) & ~_PAGE_A))
 313 #define pte_mkyoung(pte)        (__pte(pte_val(pte) | _PAGE_A))
 314 #define pte_mkclean(pte)        (__pte(pte_val(pte) & ~_PAGE_D))
 315 #define pte_mkdirty(pte)        (__pte(pte_val(pte) | _PAGE_D))
 316 #define pte_mkhuge(pte)         (__pte(pte_val(pte)))
 317
 318 /*
 319  * Macro to a page protection value as "uncacheable".  Note that "protection" is really a
 320  * misnomer here as the protection value contains the memory attribute bits, dirty bits,
 321  * and various other bits as well.
 322  */
 323 #define pgprot_noncached(prot)          __pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_UC)
 324
 325 /*
 326  * Macro to make mark a page protection value as "write-combining".
 327  * Note that "protection" is really a misnomer here as the protection
 328  * value contains the memory attribute bits, dirty bits, and various
 329  * other bits as well.  Accesses through a write-combining translation
 330  * works bypasses the caches, but does allow for consecutive writes to
 331  * be combined into single (but larger) write transactions.
 332  */
 333 #define pgprot_writecombine(prot)       __pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WC)
 334
 335 static inline unsigned long
 336 pgd_index (unsigned long address)
 337 {
 338         unsigned long region = address >> 61;
 339         unsigned long l1index = (address >> PGDIR_SHIFT) & ((PTRS_PER_PGD >> 3) - 1);
 340
 341         return (region << (PAGE_SHIFT - 6)) | l1index;
 342 }
 343
 344 /* The offset in the 1-level directory is given by the 3 region bits
 345    (61..63) and the level-1 bits.  */
 346 static inline pgd_t*
 347 pgd_offset (struct mm_struct *mm, unsigned long address)
 348 {
 349         return mm->pgd + pgd_index(address);
 350 }
 351
 352 /* In the kernel's mapped region we completely ignore the region number
 353    (since we know it's in region number 5). */
 354 #define pgd_offset_k(addr) \
 355         (init_mm.pgd + (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)))
 356
 357 /* Look up a pgd entry in the gate area.  On IA-64, the gate-area
 358    resides in the kernel-mapped segment, hence we use pgd_offset_k()
 359    here.  */
 360 #define pgd_offset_gate(mm, addr)       pgd_offset_k(addr)
 361
 362 #ifdef CONFIG_PGTABLE_4
 363 /* Find an entry in the second-level page table.. */
 364 #define pud_offset(dir,addr) \
 365         ((pud_t *) pgd_page(*(dir)) + (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)))
 366 #endif
 367
 368 /* Find an entry in the third-level page table.. */
 369 #define pmd_offset(dir,addr) \
 370         ((pmd_t *) pud_page(*(dir)) + (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)))
 371
 372 /*
 373  * Find an entry in the third-level page table.  This looks more complicated than it
 374  * should be because some platforms place page tables in high memory.
 375  */
 376 #define pte_index(addr)         (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 377 #define pte_offset_kernel(dir,addr)     ((pte_t *) pmd_page_kernel(*(dir)) + pte_index(addr))
 378 #define pte_offset_map(dir,addr)        pte_offset_kernel(dir, addr)
 379 #define pte_offset_map_nested(dir,addr) pte_offset_map(dir, addr)
 380 #define pte_unmap(pte)                  do { } while (0)
 381 #define pte_unmap_nested(pte)           do { } while (0)
 382
 383 /* atomic versions of the some PTE manipulations: */
 384
 385 static inline int
 386 ptep_test_and_clear_young (struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
 387 {
 388 #ifdef CONFIG_SMP
 389         if (!pte_young(*ptep))
 390                 return 0;
 391         return test_and_clear_bit(_PAGE_A_BIT, ptep);
 392 #else
 393         pte_t pte = *ptep;
 394         if (!pte_young(pte))
 395                 return 0;
 396         set_pte_at(vma->vm_mm, addr, ptep, pte_mkold(pte));
 397         return 1;
 398 #endif
 399 }
 400
 401 static inline int
 402 ptep_test_and_clear_dirty (struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
 403 {
 404 #ifdef CONFIG_SMP
 405         if (!pte_dirty(*ptep))
 406                 return 0;
 407         return test_and_clear_bit(_PAGE_D_BIT, ptep);
 408 #else
 409         pte_t pte = *ptep;
 410         if (!pte_dirty(pte))
 411                 return 0;
 412         set_pte_at(vma->vm_mm, addr, ptep, pte_mkclean(pte));
 413         return 1;
 414 #endif
 415 }
 416
 417 static inline pte_t
 418 ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 419 {
 420 #ifdef CONFIG_SMP
 421         return __pte(xchg((long *) ptep, 0));
 422 #else
 423         pte_t pte = *ptep;
 424         pte_clear(mm, addr, ptep);
 425         return pte;
 426 #endif
 427 }
 428
 429 static inline void
 430 ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 431 {
 432 #ifdef CONFIG_SMP
 433         unsigned long new, old;
 434
 435         do {
 436                 old = pte_val(*ptep);
 437                 new = pte_val(pte_wrprotect(__pte (old)));
 438         } while (cmpxchg((unsigned long *) ptep, old, new) != old);
 439 #else
 440         pte_t old_pte = *ptep;
 441         set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
 442 #endif
 443 }
 444
 445 static inline int
 446 pte_same (pte_t a, pte_t b)
 447 {
 448         return pte_val(a) == pte_val(b);
 449 }
 450
 451 #define update_mmu_cache(vma, address, pte) do { } while (0)
 452
 453 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 454 extern void paging_init (void);
 455
 456 /*
 457  * Note: The macros below rely on the fact that MAX_SWAPFILES_SHIFT <= number of
 458  *       bits in the swap-type field of the swap pte.  It would be nice to
 459  *       enforce that, but we can't easily include <linux/swap.h> here.
 460  *       (Of course, better still would be to define MAX_SWAPFILES_SHIFT here...).
 461  *
 462  * Format of swap pte:
 463  *      bit   0   : present bit (must be zero)
 464  *      bit   1   : _PAGE_FILE (must be zero)
 465  *      bits  2- 8: swap-type
 466  *      bits  9-62: swap offset
 467  *      bit  63   : _PAGE_PROTNONE bit
 468  *
 469  * Format of file pte:
 470  *      bit   0   : present bit (must be zero)
 471  *      bit   1   : _PAGE_FILE (must be one)
 472  *      bits  2-62: file_offset/PAGE_SIZE
 473  *      bit  63   : _PAGE_PROTNONE bit
 474  */
 475 #define __swp_type(entry)               (((entry).val >> 2) & 0x7f)
 476 #define __swp_offset(entry)             (((entry).val << 1) >> 10)
 477 #define __swp_entry(type,offset)        ((swp_entry_t) { ((type) << 2) | ((long) (offset) << 9) })
 478 #define __pte_to_swp_entry(pte)         ((swp_entry_t) { pte_val(pte) })
 479 #define __swp_entry_to_pte(x)           ((pte_t) { (x).val })
 480
 481 #define PTE_FILE_MAX_BITS               61
 482 #define pte_to_pgoff(pte)               ((pte_val(pte) << 1) >> 3)
 483 #define pgoff_to_pte(off)               ((pte_t) { ((off) << 2) | _PAGE_FILE })
 484
 485 #define io_remap_pfn_range(vma, vaddr, pfn, size, prot)         \
 486                 remap_pfn_range(vma, vaddr, pfn, size, prot)
 487
 488 #define MK_IOSPACE_PFN(space, pfn)      (pfn)
 489 #define GET_IOSPACE(pfn)                0
 490 #define GET_PFN(pfn)                    (pfn)
 491
 492 /*
 493  * ZERO_PAGE is a global shared page that is always zero: used
 494  * for zero-mapped memory areas etc..
 495  */
 496 extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
 497 extern struct page *zero_page_memmap_ptr;
 498 #define ZERO_PAGE(vaddr) (zero_page_memmap_ptr)
 499
 500 /* We provide our own get_unmapped_area to cope with VA holes for userland */
 501 #define HAVE_ARCH_UNMAPPED_AREA
 502
 503 #ifdef CONFIG_HUGETLB_PAGE
 504 #define HUGETLB_PGDIR_SHIFT     (HPAGE_SHIFT + 2*(PAGE_SHIFT-3))
 505 #define HUGETLB_PGDIR_SIZE      (__IA64_UL(1) << HUGETLB_PGDIR_SHIFT)
 506 #define HUGETLB_PGDIR_MASK      (~(HUGETLB_PGDIR_SIZE-1))
 507 #endif
 508
 509 /*
 510  * IA-64 doesn't have any external MMU info: the page tables contain all the necessary
 511  * information.  However, we use this routine to take care of any (delayed) i-cache
 512  * flushing that may be necessary.
 513  */
 514 extern void lazy_mmu_prot_update (pte_t pte);
 515
 516 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 517 /*
 518  * Update PTEP with ENTRY, which is guaranteed to be a less
 519  * restrictive PTE.  That is, ENTRY may have the ACCESSED, DIRTY, and
 520  * WRITABLE bits turned on, when the value at PTEP did not.  The
 521  * WRITABLE bit may only be turned if SAFELY_WRITABLE is TRUE.
 522  *
 523  * SAFELY_WRITABLE is TRUE if we can update the value at PTEP without
 524  * having to worry about races.  On SMP machines, there are only two
 525  * cases where this is true:
 526  *
 527  *      (1) *PTEP has the PRESENT bit turned OFF
 528  *      (2) ENTRY has the DIRTY bit turned ON
 529  *
 530  * On ia64, we could implement this routine with a cmpxchg()-loop
 531  * which ORs in the _PAGE_A/_PAGE_D bit if they're set in ENTRY.
 532  * However, like on x86, we can get a more streamlined version by
 533  * observing that it is OK to drop ACCESSED bit updates when
 534  * SAFELY_WRITABLE is FALSE.  Besides being rare, all that would do is
 535  * result in an extra Access-bit fault, which would then turn on the
 536  * ACCESSED bit in the low-level fault handler (iaccess_bit or
 537  * daccess_bit in ivt.S).
 538  */
 539 #ifdef CONFIG_SMP
 540 # define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable)       \
 541 do {                                                                                    \
 542         if (__safely_writable) {                                                        \
 543                 set_pte(__ptep, __entry);                                               \
 544                 flush_tlb_page(__vma, __addr);                                          \
 545         }                                                                               \
 546 } while (0)
 547 #else
 548 # define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable)       \
 549         ptep_establish(__vma, __addr, __ptep, __entry)
 550 #endif
 551
 552 #  ifdef CONFIG_VIRTUAL_MEM_MAP
 553   /* arch mem_map init routine is needed due to holes in a virtual mem_map */
 554 #   define __HAVE_ARCH_MEMMAP_INIT
 555     extern void memmap_init (unsigned long size, int nid, unsigned long zone,
 556                              unsigned long start_pfn);
 557 #  endif /* CONFIG_VIRTUAL_MEM_MAP */
 558 # endif /* !__ASSEMBLY__ */
 559
 560 /*
 561  * Identity-mapped regions use a large page size.  We'll call such large pages
 562  * "granules".  If you can think of a better name that's unambiguous, let me
 563  * know...
 564  */
 565 #if defined(CONFIG_IA64_GRANULE_64MB)
 566 # define IA64_GRANULE_SHIFT     _PAGE_SIZE_64M
 567 #elif defined(CONFIG_IA64_GRANULE_16MB)
 568 # define IA64_GRANULE_SHIFT     _PAGE_SIZE_16M
 569 #endif
 570 #define IA64_GRANULE_SIZE       (1 << IA64_GRANULE_SHIFT)
 571 /*
 572  * log2() of the page size we use to map the kernel image (IA64_TR_KERNEL):
 573  */
 574 #define KERNEL_TR_PAGE_SHIFT    _PAGE_SIZE_64M
 575 #define KERNEL_TR_PAGE_SIZE     (1 << KERNEL_TR_PAGE_SHIFT)
 576
 577 /*
 578  * No page table caches to initialise
 579  */
 580 #define pgtable_cache_init()    do { } while (0)
 581
 582 /* These tell get_user_pages() that the first gate page is accessible from user-level.  */
 583 #define FIXADDR_USER_START      GATE_ADDR
 584 #ifdef HAVE_BUGGY_SEGREL
 585 # define FIXADDR_USER_END       (GATE_ADDR + 2*PAGE_SIZE)
 586 #else
 587 # define FIXADDR_USER_END       (GATE_ADDR + 2*PERCPU_PAGE_SIZE)
 588 #endif
 589
 590 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 591 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
 592 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 593 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
 594 #define __HAVE_ARCH_PTE_SAME
 595 #define __HAVE_ARCH_PGD_OFFSET_GATE
 596 #define __HAVE_ARCH_LAZY_MMU_PROT_UPDATE
 597
 598 #ifndef CONFIG_PGTABLE_4
 599 #include <asm-generic/pgtable-nopud.h>
 600 #endif
 601 #include <asm-generic/pgtable.h>
 602
 603 #endif /* _ASM_IA64_PGTABLE_H */