include/asm-ppc64/pgtable.h

   1 #ifndef _PPC64_PGTABLE_H
   2 #define _PPC64_PGTABLE_H
   3
   4 /*
   5  * This file contains the functions and defines necessary to modify and use
   6  * the ppc64 hashed page table.
   7  */
   8
   9 #ifndef __ASSEMBLY__
  10 #include <linux/config.h>
  11 #include <linux/stddef.h>
  12 #include <asm/processor.h>              /* For TASK_SIZE */
  13 #include <asm/mmu.h>
  14 #include <asm/page.h>
  15 #include <asm/tlbflush.h>
  16 #endif /* __ASSEMBLY__ */
  17
  18 #include <asm-generic/pgtable-nopud.h>
  19
  20 /*
  21  * Entries per page directory level.  The PTE level must use a 64b record
  22  * for each page table entry.  The PMD and PGD level use a 32b record for
  23  * each entry by assuming that each entry is page aligned.
  24  */
  25 #define PTE_INDEX_SIZE  9
  26 #define PMD_INDEX_SIZE  10
  27 #define PGD_INDEX_SIZE  10
  28
  29 #define PTRS_PER_PTE    (1 << PTE_INDEX_SIZE)
  30 #define PTRS_PER_PMD    (1 << PMD_INDEX_SIZE)
  31 #define PTRS_PER_PGD    (1 << PGD_INDEX_SIZE)
  32
  33 /* PMD_SHIFT determines what a second-level page table entry can map */
  34 #define PMD_SHIFT       (PAGE_SHIFT + PTE_INDEX_SIZE)
  35 #define PMD_SIZE        (1UL << PMD_SHIFT)
  36 #define PMD_MASK        (~(PMD_SIZE-1))
  37
  38 /* PGDIR_SHIFT determines what a third-level page table entry can map */
  39 #define PGDIR_SHIFT     (PMD_SHIFT + PMD_INDEX_SIZE)
  40 #define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  41 #define PGDIR_MASK      (~(PGDIR_SIZE-1))
  42
  43 #define FIRST_USER_ADDRESS      0
  44
  45 /*
  46  * Size of EA range mapped by our pagetables.
  47  */
  48 #define EADDR_SIZE (PTE_INDEX_SIZE + PMD_INDEX_SIZE + \
  49                     PGD_INDEX_SIZE + PAGE_SHIFT)
  50 #define EADDR_MASK ((1UL << EADDR_SIZE) - 1)
  51
  52 /*
  53  * Define the address range of the vmalloc VM area.
  54  */
  55 #define VMALLOC_START (0xD000000000000000ul)
  56 #define VMALLOC_END   (VMALLOC_START + EADDR_MASK)
  57
  58 /*
  59  * Bits in a linux-style PTE.  These match the bits in the
  60  * (hardware-defined) PowerPC PTE as closely as possible.
  61  */
  62 #define _PAGE_PRESENT   0x0001 /* software: pte contains a translation */
  63 #define _PAGE_USER      0x0002 /* matches one of the PP bits */
  64 #define _PAGE_FILE      0x0002 /* (!present only) software: pte holds file offset */
  65 #define _PAGE_EXEC      0x0004 /* No execute on POWER4 and newer (we invert) */
  66 #define _PAGE_GUARDED   0x0008
  67 #define _PAGE_COHERENT  0x0010 /* M: enforce memory coherence (SMP systems) */
  68 #define _PAGE_NO_CACHE  0x0020 /* I: cache inhibit */
  69 #define _PAGE_WRITETHRU 0x0040 /* W: cache write-through */
  70 #define _PAGE_DIRTY     0x0080 /* C: page changed */
  71 #define _PAGE_ACCESSED  0x0100 /* R: page referenced */
  72 #define _PAGE_RW        0x0200 /* software: user write access allowed */
  73 #define _PAGE_HASHPTE   0x0400 /* software: pte has an associated HPTE */
  74 #define _PAGE_BUSY      0x0800 /* software: PTE & hash are busy */
  75 #define _PAGE_SECONDARY 0x8000 /* software: HPTE is in secondary group */
  76 #define _PAGE_GROUP_IX  0x7000 /* software: HPTE index within group */
  77 #define _PAGE_HUGE      0x10000 /* 16MB page */
  78 /* Bits 0x7000 identify the index within an HPT Group */
  79 #define _PAGE_HPTEFLAGS (_PAGE_BUSY | _PAGE_HASHPTE | _PAGE_SECONDARY | _PAGE_GROUP_IX)
  80 /* PAGE_MASK gives the right answer below, but only by accident */
  81 /* It should be preserving the high 48 bits and then specifically */
  82 /* preserving _PAGE_SECONDARY | _PAGE_GROUP_IX */
  83 #define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_HPTEFLAGS)
  84
  85 #define _PAGE_BASE      (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_COHERENT)
  86
  87 #define _PAGE_WRENABLE  (_PAGE_RW | _PAGE_DIRTY)
  88
  89 /* __pgprot defined in asm-ppc64/page.h */
  90 #define PAGE_NONE       __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED)
  91
  92 #define PAGE_SHARED     __pgprot(_PAGE_BASE | _PAGE_RW | _PAGE_USER)
  93 #define PAGE_SHARED_X   __pgprot(_PAGE_BASE | _PAGE_RW | _PAGE_USER | _PAGE_EXEC)
  94 #define PAGE_COPY       __pgprot(_PAGE_BASE | _PAGE_USER)
  95 #define PAGE_COPY_X     __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
  96 #define PAGE_READONLY   __pgprot(_PAGE_BASE | _PAGE_USER)
  97 #define PAGE_READONLY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
  98 #define PAGE_KERNEL     __pgprot(_PAGE_BASE | _PAGE_WRENABLE)
  99 #define PAGE_KERNEL_CI  __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
 100                                _PAGE_WRENABLE | _PAGE_NO_CACHE | _PAGE_GUARDED)
 101 #define PAGE_KERNEL_EXEC __pgprot(_PAGE_BASE | _PAGE_WRENABLE | _PAGE_EXEC)
 102
 103 #define PAGE_AGP        __pgprot(_PAGE_BASE | _PAGE_WRENABLE | _PAGE_NO_CACHE)
 104 #define HAVE_PAGE_AGP
 105
 106 /*
 107  * This bit in a hardware PTE indicates that the page is *not* executable.
 108  */
 109 #define HW_NO_EXEC      _PAGE_EXEC
 110
 111 /*
 112  * POWER4 and newer have per page execute protection, older chips can only
 113  * do this on a segment (256MB) basis.
 114  *
 115  * Also, write permissions imply read permissions.
 116  * This is the closest we can get..
 117  *
 118  * Note due to the way vm flags are laid out, the bits are XWR
 119  */
 120 #define __P000  PAGE_NONE
 121 #define __P001  PAGE_READONLY
 122 #define __P010  PAGE_COPY
 123 #define __P011  PAGE_COPY
 124 #define __P100  PAGE_READONLY_X
 125 #define __P101  PAGE_READONLY_X
 126 #define __P110  PAGE_COPY_X
 127 #define __P111  PAGE_COPY_X
 128
 129 #define __S000  PAGE_NONE
 130 #define __S001  PAGE_READONLY
 131 #define __S010  PAGE_SHARED
 132 #define __S011  PAGE_SHARED
 133 #define __S100  PAGE_READONLY_X
 134 #define __S101  PAGE_READONLY_X
 135 #define __S110  PAGE_SHARED_X
 136 #define __S111  PAGE_SHARED_X
 137
 138 #ifndef __ASSEMBLY__
 139
 140 /*
 141  * ZERO_PAGE is a global shared page that is always zero: used
 142  * for zero-mapped memory areas etc..
 143  */
 144 extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
 145 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
 146 #endif /* __ASSEMBLY__ */
 147
 148 /* shift to put page number into pte */
 149 #define PTE_SHIFT (17)
 150
 151 #ifdef CONFIG_HUGETLB_PAGE
 152
 153 #ifndef __ASSEMBLY__
 154 int hash_huge_page(struct mm_struct *mm, unsigned long access,
 155                    unsigned long ea, unsigned long vsid, int local);
 156
 157 void hugetlb_mm_free_pgd(struct mm_struct *mm);
 158 #endif /* __ASSEMBLY__ */
 159
 160 #define HAVE_ARCH_UNMAPPED_AREA
 161 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 162 #else
 163
 164 #define hash_huge_page(mm,a,ea,vsid,local)      -1
 165 #define hugetlb_mm_free_pgd(mm)                 do {} while (0)
 166
 167 #endif
 168
 169 #ifndef __ASSEMBLY__
 170
 171 /*
 172  * Conversion functions: convert a page and protection to a page entry,
 173  * and a page entry and page directory to the page they refer to.
 174  *
 175  * mk_pte takes a (struct page *) as input
 176  */
 177 #define mk_pte(page, pgprot)    pfn_pte(page_to_pfn(page), (pgprot))
 178
 179 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
 180 {
 181         pte_t pte;
 182
 183
 184         pte_val(pte) = (pfn << PTE_SHIFT) | pgprot_val(pgprot);
 185         return pte;
 186 }
 187
 188 #define pte_modify(_pte, newprot) \
 189   (__pte((pte_val(_pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)))
 190
 191 #define pte_none(pte)           ((pte_val(pte) & ~_PAGE_HPTEFLAGS) == 0)
 192 #define pte_present(pte)        (pte_val(pte) & _PAGE_PRESENT)
 193
 194 /* pte_clear moved to later in this file */
 195
 196 #define pte_pfn(x)              ((unsigned long)((pte_val(x) >> PTE_SHIFT)))
 197 #define pte_page(x)             pfn_to_page(pte_pfn(x))
 198
 199 #define pmd_set(pmdp, ptep)     \
 200         (pmd_val(*(pmdp)) = __ba_to_bpn(ptep))
 201 #define pmd_none(pmd)           (!pmd_val(pmd))
 202 #define pmd_bad(pmd)            (pmd_val(pmd) == 0)
 203 #define pmd_present(pmd)        (pmd_val(pmd) != 0)
 204 #define pmd_clear(pmdp)         (pmd_val(*(pmdp)) = 0)
 205 #define pmd_page_kernel(pmd)    (__bpn_to_ba(pmd_val(pmd)))
 206 #define pmd_page(pmd)           virt_to_page(pmd_page_kernel(pmd))
 207
 208 #define pud_set(pudp, pmdp)     (pud_val(*(pudp)) = (__ba_to_bpn(pmdp)))
 209 #define pud_none(pud)           (!pud_val(pud))
 210 #define pud_bad(pud)            ((pud_val(pud)) == 0UL)
 211 #define pud_present(pud)        (pud_val(pud) != 0UL)
 212 #define pud_clear(pudp)         (pud_val(*(pudp)) = 0UL)
 213 #define pud_page(pud)           (__bpn_to_ba(pud_val(pud)))
 214
 215 /*
 216  * Find an entry in a page-table-directory.  We combine the address region
 217  * (the high order N bits) and the pgd portion of the address.
 218  */
 219 /* to avoid overflow in free_pgtables we don't use PTRS_PER_PGD here */
 220 #define pgd_index(address) (((address) >> (PGDIR_SHIFT)) & 0x7ff)
 221
 222 #define pgd_offset(mm, address)  ((mm)->pgd + pgd_index(address))
 223
 224 /* Find an entry in the second-level page table.. */
 225 #define pmd_offset(pudp,addr) \
 226   ((pmd_t *) pud_page(*(pudp)) + (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)))
 227
 228 /* Find an entry in the third-level page table.. */
 229 #define pte_offset_kernel(dir,addr) \
 230   ((pte_t *) pmd_page_kernel(*(dir)) \
 231  + (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
 232
 233 #define pte_offset_map(dir,addr)        pte_offset_kernel((dir), (addr))
 234 #define pte_offset_map_nested(dir,addr) pte_offset_kernel((dir), (addr))
 235 #define pte_unmap(pte)                  do { } while(0)
 236 #define pte_unmap_nested(pte)           do { } while(0)
 237
 238 /* to find an entry in a kernel page-table-directory */
 239 /* This now only contains the vmalloc pages */
 240 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 241
 242 /* to find an entry in the ioremap page-table-directory */
 243 #define pgd_offset_i(address) (ioremap_pgd + pgd_index(address))
 244
 245 /*
 246  * The following only work if pte_present() is true.
 247  * Undefined behaviour if not..
 248  */
 249 static inline int pte_read(pte_t pte)  { return pte_val(pte) & _PAGE_USER;}
 250 static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW;}
 251 static inline int pte_exec(pte_t pte)  { return pte_val(pte) & _PAGE_EXEC;}
 252 static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY;}
 253 static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED;}
 254 static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE;}
 255 static inline int pte_huge(pte_t pte) { return pte_val(pte) & _PAGE_HUGE;}
 256
 257 static inline void pte_uncache(pte_t pte) { pte_val(pte) |= _PAGE_NO_CACHE; }
 258 static inline void pte_cache(pte_t pte)   { pte_val(pte) &= ~_PAGE_NO_CACHE; }
 259
 260 static inline pte_t pte_rdprotect(pte_t pte) {
 261         pte_val(pte) &= ~_PAGE_USER; return pte; }
 262 static inline pte_t pte_exprotect(pte_t pte) {
 263         pte_val(pte) &= ~_PAGE_EXEC; return pte; }
 264 static inline pte_t pte_wrprotect(pte_t pte) {
 265         pte_val(pte) &= ~(_PAGE_RW); return pte; }
 266 static inline pte_t pte_mkclean(pte_t pte) {
 267         pte_val(pte) &= ~(_PAGE_DIRTY); return pte; }
 268 static inline pte_t pte_mkold(pte_t pte) {
 269         pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
 270
 271 static inline pte_t pte_mkread(pte_t pte) {
 272         pte_val(pte) |= _PAGE_USER; return pte; }
 273 static inline pte_t pte_mkexec(pte_t pte) {
 274         pte_val(pte) |= _PAGE_USER | _PAGE_EXEC; return pte; }
 275 static inline pte_t pte_mkwrite(pte_t pte) {
 276         pte_val(pte) |= _PAGE_RW; return pte; }
 277 static inline pte_t pte_mkdirty(pte_t pte) {
 278         pte_val(pte) |= _PAGE_DIRTY; return pte; }
 279 static inline pte_t pte_mkyoung(pte_t pte) {
 280         pte_val(pte) |= _PAGE_ACCESSED; return pte; }
 281 static inline pte_t pte_mkhuge(pte_t pte) {
 282         pte_val(pte) |= _PAGE_HUGE; return pte; }
 283
 284 /* Atomic PTE updates */
 285 static inline unsigned long pte_update(pte_t *p, unsigned long clr)
 286 {
 287         unsigned long old, tmp;
 288
 289         __asm__ __volatile__(
 290         "1:     ldarx   %0,0,%3         # pte_update\n\
 291         andi.   %1,%0,%6\n\
 292         bne-    1b \n\
 293         andc    %1,%0,%4 \n\
 294         stdcx.  %1,0,%3 \n\
 295         bne-    1b"
 296         : "=&r" (old), "=&r" (tmp), "=m" (*p)
 297         : "r" (p), "r" (clr), "m" (*p), "i" (_PAGE_BUSY)
 298         : "cc" );
 299         return old;
 300 }
 301
 302 /* PTE updating functions, this function puts the PTE in the
 303  * batch, doesn't actually triggers the hash flush immediately,
 304  * you need to call flush_tlb_pending() to do that.
 305  */
 306 extern void hpte_update(struct mm_struct *mm, unsigned long addr, unsigned long pte,
 307                         int wrprot);
 308
 309 static inline int __ptep_test_and_clear_young(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 310 {
 311         unsigned long old;
 312
 313         if ((pte_val(*ptep) & (_PAGE_ACCESSED | _PAGE_HASHPTE)) == 0)
 314                 return 0;
 315         old = pte_update(ptep, _PAGE_ACCESSED);
 316         if (old & _PAGE_HASHPTE) {
 317                 hpte_update(mm, addr, old, 0);
 318                 flush_tlb_pending();
 319         }
 320         return (old & _PAGE_ACCESSED) != 0;
 321 }
 322 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 323 #define ptep_test_and_clear_young(__vma, __addr, __ptep)                   \
 324 ({                                                                         \
 325         int __r;                                                           \
 326         __r = __ptep_test_and_clear_young((__vma)->vm_mm, __addr, __ptep); \
 327         __r;                                                               \
 328 })
 329
 330 /*
 331  * On RW/DIRTY bit transitions we can avoid flushing the hpte. For the
 332  * moment we always flush but we need to fix hpte_update and test if the
 333  * optimisation is worth it.
 334  */
 335 static inline int __ptep_test_and_clear_dirty(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 336 {
 337         unsigned long old;
 338
 339         if ((pte_val(*ptep) & _PAGE_DIRTY) == 0)
 340                 return 0;
 341         old = pte_update(ptep, _PAGE_DIRTY);
 342         if (old & _PAGE_HASHPTE)
 343                 hpte_update(mm, addr, old, 0);
 344         return (old & _PAGE_DIRTY) != 0;
 345 }
 346 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
 347 #define ptep_test_and_clear_dirty(__vma, __addr, __ptep)                   \
 348 ({                                                                         \
 349         int __r;                                                           \
 350         __r = __ptep_test_and_clear_dirty((__vma)->vm_mm, __addr, __ptep); \
 351         __r;                                                               \
 352 })
 353
 354 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
 355 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 356 {
 357         unsigned long old;
 358
 359         if ((pte_val(*ptep) & _PAGE_RW) == 0)
 360                 return;
 361         old = pte_update(ptep, _PAGE_RW);
 362         if (old & _PAGE_HASHPTE)
 363                 hpte_update(mm, addr, old, 0);
 364 }
 365
 366 /*
 367  * We currently remove entries from the hashtable regardless of whether
 368  * the entry was young or dirty. The generic routines only flush if the
 369  * entry was young or dirty which is not good enough.
 370  *
 371  * We should be more intelligent about this but for the moment we override
 372  * these functions and force a tlb flush unconditionally
 373  */
 374 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
 375 #define ptep_clear_flush_young(__vma, __address, __ptep)                \
 376 ({                                                                      \
 377         int __young = __ptep_test_and_clear_young((__vma)->vm_mm, __address, \
 378                                                   __ptep);              \
 379         __young;                                                        \
 380 })
 381
 382 #define __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
 383 #define ptep_clear_flush_dirty(__vma, __address, __ptep)                \
 384 ({                                                                      \
 385         int __dirty = __ptep_test_and_clear_dirty((__vma)->vm_mm, __address, \
 386                                                   __ptep);              \
 387         flush_tlb_page(__vma, __address);                               \
 388         __dirty;                                                        \
 389 })
 390
 391 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 392 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 393 {
 394         unsigned long old = pte_update(ptep, ~0UL);
 395
 396         if (old & _PAGE_HASHPTE)
 397                 hpte_update(mm, addr, old, 0);
 398         return __pte(old);
 399 }
 400
 401 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t * ptep)
 402 {
 403         unsigned long old = pte_update(ptep, ~0UL);
 404
 405         if (old & _PAGE_HASHPTE)
 406                 hpte_update(mm, addr, old, 0);
 407 }
 408
 409 /*
 410  * set_pte stores a linux PTE into the linux page table.
 411  */
 412 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 413                               pte_t *ptep, pte_t pte)
 414 {
 415         if (pte_present(*ptep)) {
 416                 pte_clear(mm, addr, ptep);
 417                 flush_tlb_pending();
 418         }
 419         *ptep = __pte(pte_val(pte) & ~_PAGE_HPTEFLAGS);
 420 }
 421
 422 /* Set the dirty and/or accessed bits atomically in a linux PTE, this
 423  * function doesn't need to flush the hash entry
 424  */
 425 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 426 static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry, int dirty)
 427 {
 428         unsigned long bits = pte_val(entry) &
 429                 (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC);
 430         unsigned long old, tmp;
 431
 432         __asm__ __volatile__(
 433         "1:     ldarx   %0,0,%4\n\
 434                 andi.   %1,%0,%6\n\
 435                 bne-    1b \n\
 436                 or      %0,%3,%0\n\
 437                 stdcx.  %0,0,%4\n\
 438                 bne-    1b"
 439         :"=&r" (old), "=&r" (tmp), "=m" (*ptep)
 440         :"r" (bits), "r" (ptep), "m" (*ptep), "i" (_PAGE_BUSY)
 441         :"cc");
 442 }
 443 #define  ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
 444         do {                                                               \
 445                 __ptep_set_access_flags(__ptep, __entry, __dirty);         \
 446                 flush_tlb_page_nohash(__vma, __address);                   \
 447         } while(0)
 448
 449 /*
 450  * Macro to mark a page protection value as "uncacheable".
 451  */
 452 #define pgprot_noncached(prot)  (__pgprot(pgprot_val(prot) | _PAGE_NO_CACHE | _PAGE_GUARDED))
 453
 454 struct file;
 455 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr,
 456                                      unsigned long size, pgprot_t vma_prot);
 457 #define __HAVE_PHYS_MEM_ACCESS_PROT
 458
 459 #define __HAVE_ARCH_PTE_SAME
 460 #define pte_same(A,B)   (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HPTEFLAGS) == 0)
 461
 462 extern unsigned long ioremap_bot, ioremap_base;
 463
 464 #define pmd_ERROR(e) \
 465         printk("%s:%d: bad pmd %08x.\n", __FILE__, __LINE__, pmd_val(e))
 466 #define pgd_ERROR(e) \
 467         printk("%s:%d: bad pgd %08x.\n", __FILE__, __LINE__, pgd_val(e))
 468
 469 extern pgd_t swapper_pg_dir[];
 470 extern pgd_t ioremap_dir[];
 471
 472 extern void paging_init(void);
 473
 474 /*
 475  * Because the huge pgtables are only 2 level, they can take
 476  * at most around 4M, much less than one hugepage which the
 477  * process is presumably entitled to use.  So we don't bother
 478  * freeing up the pagetables on unmap, and wait until
 479  * destroy_context() to clean up the lot.
 480  */
 481 #define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) \
 482                                                 do { } while (0)
 483
 484 /*
 485  * This gets called at the end of handling a page fault, when
 486  * the kernel has put a new PTE into the page table for the process.
 487  * We use it to put a corresponding HPTE into the hash table
 488  * ahead of time, instead of waiting for the inevitable extra
 489  * hash-table miss exception.
 490  */
 491 struct vm_area_struct;
 492 extern void update_mmu_cache(struct vm_area_struct *, unsigned long, pte_t);
 493
 494 /* Encode and de-code a swap entry */
 495 #define __swp_type(entry)       (((entry).val >> 1) & 0x3f)
 496 #define __swp_offset(entry)     ((entry).val >> 8)
 497 #define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 1) | ((offset) << 8) })
 498 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) >> PTE_SHIFT })
 499 #define __swp_entry_to_pte(x)   ((pte_t) { (x).val << PTE_SHIFT })
 500 #define pte_to_pgoff(pte)       (pte_val(pte) >> PTE_SHIFT)
 501 #define pgoff_to_pte(off)       ((pte_t) {((off) << PTE_SHIFT)|_PAGE_FILE})
 502 #define PTE_FILE_MAX_BITS       (BITS_PER_LONG - PTE_SHIFT)
 503
 504 /*
 505  * kern_addr_valid is intended to indicate whether an address is a valid
 506  * kernel address.  Most 32-bit archs define it as always true (like this)
 507  * but most 64-bit archs actually perform a test.  What should we do here?
 508  * The only use is in fs/ncpfs/dir.c
 509  */
 510 #define kern_addr_valid(addr)   (1)
 511
 512 #define io_remap_pfn_range(vma, vaddr, pfn, size, prot)         \
 513                 remap_pfn_range(vma, vaddr, pfn, size, prot)
 514
 515 void pgtable_cache_init(void);
 516
 517 /*
 518  * find_linux_pte returns the address of a linux pte for a given
 519  * effective address and directory.  If not found, it returns zero.
 520  */
 521 static inline pte_t *find_linux_pte(pgd_t *pgdir, unsigned long ea)
 522 {
 523         pgd_t *pg;
 524         pud_t *pu;
 525         pmd_t *pm;
 526         pte_t *pt = NULL;
 527         pte_t pte;
 528
 529         pg = pgdir + pgd_index(ea);
 530         if (!pgd_none(*pg)) {
 531                 pu = pud_offset(pg, ea);
 532                 if (!pud_none(*pu)) {
 533                         pm = pmd_offset(pu, ea);
 534                         if (pmd_present(*pm)) {
 535                                 pt = pte_offset_kernel(pm, ea);
 536                                 pte = *pt;
 537                                 if (!pte_present(pte))
 538                                         pt = NULL;
 539                         }
 540                 }
 541         }
 542
 543         return pt;
 544 }
 545
 546 #include <asm-generic/pgtable.h>
 547
 548 #endif /* __ASSEMBLY__ */
 549
 550 #endif /* _PPC64_PGTABLE_H */