include/asm-generic/pgtable.h

   1 #ifndef _ASM_GENERIC_PGTABLE_H
   2 #define _ASM_GENERIC_PGTABLE_H
   3
   4 #ifndef __ASSEMBLY__
   5 #ifdef CONFIG_MMU
   6
   7 #include <linux/mm_types.h>
   8
   9 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
  10 extern int ptep_set_access_flags(struct vm_area_struct *vma,
  11                                  unsigned long address, pte_t *ptep,
  12                                  pte_t entry, int dirty);
  13 #endif
  14
  15 #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
  16 extern int pmdp_set_access_flags(struct vm_area_struct *vma,
  17                                  unsigned long address, pmd_t *pmdp,
  18                                  pmd_t entry, int dirty);
  19 #endif
  20
  21 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
  22 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
  23                                             unsigned long address,
  24                                             pte_t *ptep)
  25 {
  26         pte_t pte = *ptep;
  27         int r = 1;
  28         if (!pte_young(pte))
  29                 r = 0;
  30         else
  31                 set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
  32         return r;
  33 }
  34 #endif
  35
  36 #ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
  37 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  38 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
  39                                             unsigned long address,
  40                                             pmd_t *pmdp)
  41 {
  42         pmd_t pmd = *pmdp;
  43         int r = 1;
  44         if (!pmd_young(pmd))
  45                 r = 0;
  46         else
  47                 set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
  48         return r;
  49 }
  50 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
  51 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
  52                                             unsigned long address,
  53                                             pmd_t *pmdp)
  54 {
  55         BUG();
  56         return 0;
  57 }
  58 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  59 #endif
  60
  61 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
  62 int ptep_clear_flush_young(struct vm_area_struct *vma,
  63                            unsigned long address, pte_t *ptep);
  64 #endif
  65
  66 #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
  67 int pmdp_clear_flush_young(struct vm_area_struct *vma,
  68                            unsigned long address, pmd_t *pmdp);
  69 #endif
  70
  71 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
  72 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
  73                                        unsigned long address,
  74                                        pte_t *ptep)
  75 {
  76         pte_t pte = *ptep;
  77         pte_clear(mm, address, ptep);
  78         return pte;
  79 }
  80 #endif
  81
  82 #ifndef __HAVE_ARCH_PMDP_GET_AND_CLEAR
  83 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  84 static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
  85                                        unsigned long address,
  86                                        pmd_t *pmdp)
  87 {
  88         pmd_t pmd = *pmdp;
  89         pmd_clear(mm, address, pmdp);
  90         return pmd;
  91 })
  92 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  93 #endif
  94
  95 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
  96 static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
  97                                             unsigned long address, pte_t *ptep,
  98                                             int full)
  99 {
 100         pte_t pte;
 101         pte = ptep_get_and_clear(mm, address, ptep);
 102         return pte;
 103 }
 104 #endif
 105
 106 /*
 107  * Some architectures may be able to avoid expensive synchronization
 108  * primitives when modifications are made to PTE's which are already
 109  * not present, or in the process of an address space destruction.
 110  */
 111 #ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
 112 static inline void pte_clear_not_present_full(struct mm_struct *mm,
 113                                               unsigned long address,
 114                                               pte_t *ptep,
 115                                               int full)
 116 {
 117         pte_clear(mm, address, ptep);
 118 }
 119 #endif
 120
 121 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
 122 extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
 123                               unsigned long address,
 124                               pte_t *ptep);
 125 #endif
 126
 127 #ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
 128 extern pmd_t pmdp_clear_flush(struct vm_area_struct *vma,
 129                               unsigned long address,
 130                               pmd_t *pmdp);
 131 #endif
 132
 133 #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
 134 struct mm_struct;
 135 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
 136 {
 137         pte_t old_pte = *ptep;
 138         set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
 139 }
 140 #endif
 141
 142 #ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
 143 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 144 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 145                                       unsigned long address, pmd_t *pmdp)
 146 {
 147         pmd_t old_pmd = *pmdp;
 148         set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
 149 }
 150 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 151 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 152                                       unsigned long address, pmd_t *pmdp)
 153 {
 154         BUG();
 155 }
 156 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 157 #endif
 158
 159 #ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
 160 extern pmd_t pmdp_splitting_flush(struct vm_area_struct *vma,
 161                                   unsigned long address,
 162                                   pmd_t *pmdp);
 163 #endif
 164
 165 #ifndef __HAVE_ARCH_PTE_SAME
 166 static inline int pte_same(pte_t pte_a, pte_t pte_b)
 167 {
 168         return pte_val(pte_a) == pte_val(pte_b);
 169 }
 170 #endif
 171
 172 #ifndef __HAVE_ARCH_PMD_SAME
 173 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 174 static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
 175 {
 176         return pmd_val(pmd_a) == pmd_val(pmd_b);
 177 }
 178 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 179 static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
 180 {
 181         BUG();
 182         return 0;
 183 }
 184 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 185 #endif
 186
 187 #ifndef __HAVE_ARCH_PAGE_TEST_DIRTY
 188 #define page_test_dirty(page)           (0)
 189 #endif
 190
 191 #ifndef __HAVE_ARCH_PAGE_CLEAR_DIRTY
 192 #define page_clear_dirty(page, mapped)  do { } while (0)
 193 #endif
 194
 195 #ifndef __HAVE_ARCH_PAGE_TEST_DIRTY
 196 #define pte_maybe_dirty(pte)            pte_dirty(pte)
 197 #else
 198 #define pte_maybe_dirty(pte)            (1)
 199 #endif
 200
 201 #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
 202 #define page_test_and_clear_young(page) (0)
 203 #endif
 204
 205 #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
 206 #define pgd_offset_gate(mm, addr)       pgd_offset(mm, addr)
 207 #endif
 208
 209 #ifndef __HAVE_ARCH_MOVE_PTE
 210 #define move_pte(pte, prot, old_addr, new_addr) (pte)
 211 #endif
 212
 213 #ifndef flush_tlb_fix_spurious_fault
 214 #define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
 215 #endif
 216
 217 #ifndef pgprot_noncached
 218 #define pgprot_noncached(prot)  (prot)
 219 #endif
 220
 221 #ifndef pgprot_writecombine
 222 #define pgprot_writecombine pgprot_noncached
 223 #endif
 224
 225 /*
 226  * When walking page tables, get the address of the next boundary,
 227  * or the end address of the range if that comes earlier.  Although no
 228  * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
 229  */
 230
 231 #define pgd_addr_end(addr, end)                                         \
 232 ({      unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;  \
 233         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
 234 })
 235
 236 #ifndef pud_addr_end
 237 #define pud_addr_end(addr, end)                                         \
 238 ({      unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK;      \
 239         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
 240 })
 241 #endif
 242
 243 #ifndef pmd_addr_end
 244 #define pmd_addr_end(addr, end)                                         \
 245 ({      unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK;      \
 246         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
 247 })
 248 #endif
 249
 250 /*
 251  * When walking page tables, we usually want to skip any p?d_none entries;
 252  * and any p?d_bad entries - reporting the error before resetting to none.
 253  * Do the tests inline, but report and clear the bad entry in mm/memory.c.
 254  */
 255 void pgd_clear_bad(pgd_t *);
 256 void pud_clear_bad(pud_t *);
 257 void pmd_clear_bad(pmd_t *);
 258
 259 static inline int pgd_none_or_clear_bad(pgd_t *pgd)
 260 {
 261         if (pgd_none(*pgd))
 262                 return 1;
 263         if (unlikely(pgd_bad(*pgd))) {
 264                 pgd_clear_bad(pgd);
 265                 return 1;
 266         }
 267         return 0;
 268 }
 269
 270 static inline int pud_none_or_clear_bad(pud_t *pud)
 271 {
 272         if (pud_none(*pud))
 273                 return 1;
 274         if (unlikely(pud_bad(*pud))) {
 275                 pud_clear_bad(pud);
 276                 return 1;
 277         }
 278         return 0;
 279 }
 280
 281 static inline int pmd_none_or_clear_bad(pmd_t *pmd)
 282 {
 283         if (pmd_none(*pmd))
 284                 return 1;
 285         if (unlikely(pmd_bad(*pmd))) {
 286                 pmd_clear_bad(pmd);
 287                 return 1;
 288         }
 289         return 0;
 290 }
 291
 292 static inline pte_t __ptep_modify_prot_start(struct mm_struct *mm,
 293                                              unsigned long addr,
 294                                              pte_t *ptep)
 295 {
 296         /*
 297          * Get the current pte state, but zero it out to make it
 298          * non-present, preventing the hardware from asynchronously
 299          * updating it.
 300          */
 301         return ptep_get_and_clear(mm, addr, ptep);
 302 }
 303
 304 static inline void __ptep_modify_prot_commit(struct mm_struct *mm,
 305                                              unsigned long addr,
 306                                              pte_t *ptep, pte_t pte)
 307 {
 308         /*
 309          * The pte is non-present, so there's no hardware state to
 310          * preserve.
 311          */
 312         set_pte_at(mm, addr, ptep, pte);
 313 }
 314
 315 #ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
 316 /*
 317  * Start a pte protection read-modify-write transaction, which
 318  * protects against asynchronous hardware modifications to the pte.
 319  * The intention is not to prevent the hardware from making pte
 320  * updates, but to prevent any updates it may make from being lost.
 321  *
 322  * This does not protect against other software modifications of the
 323  * pte; the appropriate pte lock must be held over the transation.
 324  *
 325  * Note that this interface is intended to be batchable, meaning that
 326  * ptep_modify_prot_commit may not actually update the pte, but merely
 327  * queue the update to be done at some later time.  The update must be
 328  * actually committed before the pte lock is released, however.
 329  */
 330 static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
 331                                            unsigned long addr,
 332                                            pte_t *ptep)
 333 {
 334         return __ptep_modify_prot_start(mm, addr, ptep);
 335 }
 336
 337 /*
 338  * Commit an update to a pte, leaving any hardware-controlled bits in
 339  * the PTE unmodified.
 340  */
 341 static inline void ptep_modify_prot_commit(struct mm_struct *mm,
 342                                            unsigned long addr,
 343                                            pte_t *ptep, pte_t pte)
 344 {
 345         __ptep_modify_prot_commit(mm, addr, ptep, pte);
 346 }
 347 #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
 348 #endif /* CONFIG_MMU */
 349
 350 /*
 351  * A facility to provide lazy MMU batching.  This allows PTE updates and
 352  * page invalidations to be delayed until a call to leave lazy MMU mode
 353  * is issued.  Some architectures may benefit from doing this, and it is
 354  * beneficial for both shadow and direct mode hypervisors, which may batch
 355  * the PTE updates which happen during this window.  Note that using this
 356  * interface requires that read hazards be removed from the code.  A read
 357  * hazard could result in the direct mode hypervisor case, since the actual
 358  * write to the page tables may not yet have taken place, so reads though
 359  * a raw PTE pointer after it has been modified are not guaranteed to be
 360  * up to date.  This mode can only be entered and left under the protection of
 361  * the page table locks for all page tables which may be modified.  In the UP
 362  * case, this is required so that preemption is disabled, and in the SMP case,
 363  * it must synchronize the delayed page table writes properly on other CPUs.
 364  */
 365 #ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
 366 #define arch_enter_lazy_mmu_mode()      do {} while (0)
 367 #define arch_leave_lazy_mmu_mode()      do {} while (0)
 368 #define arch_flush_lazy_mmu_mode()      do {} while (0)
 369 #endif
 370
 371 /*
 372  * A facility to provide batching of the reload of page tables and
 373  * other process state with the actual context switch code for
 374  * paravirtualized guests.  By convention, only one of the batched
 375  * update (lazy) modes (CPU, MMU) should be active at any given time,
 376  * entry should never be nested, and entry and exits should always be
 377  * paired.  This is for sanity of maintaining and reasoning about the
 378  * kernel code.  In this case, the exit (end of the context switch) is
 379  * in architecture-specific code, and so doesn't need a generic
 380  * definition.
 381  */
 382 #ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
 383 #define arch_start_context_switch(prev) do {} while (0)
 384 #endif
 385
 386 #ifndef __HAVE_PFNMAP_TRACKING
 387 /*
 388  * Interface that can be used by architecture code to keep track of
 389  * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
 390  *
 391  * track_pfn_vma_new is called when a _new_ pfn mapping is being established
 392  * for physical range indicated by pfn and size.
 393  */
 394 static inline int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,
 395                                         unsigned long pfn, unsigned long size)
 396 {
 397         return 0;
 398 }
 399
 400 /*
 401  * Interface that can be used by architecture code to keep track of
 402  * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
 403  *
 404  * track_pfn_vma_copy is called when vma that is covering the pfnmap gets
 405  * copied through copy_page_range().
 406  */
 407 static inline int track_pfn_vma_copy(struct vm_area_struct *vma)
 408 {
 409         return 0;
 410 }
 411
 412 /*
 413  * Interface that can be used by architecture code to keep track of
 414  * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
 415  *
 416  * untrack_pfn_vma is called while unmapping a pfnmap for a region.
 417  * untrack can be called for a specific region indicated by pfn and size or
 418  * can be for the entire vma (in which case size can be zero).
 419  */
 420 static inline void untrack_pfn_vma(struct vm_area_struct *vma,
 421                                         unsigned long pfn, unsigned long size)
 422 {
 423 }
 424 #else
 425 extern int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,
 426                                 unsigned long pfn, unsigned long size);
 427 extern int track_pfn_vma_copy(struct vm_area_struct *vma);
 428 extern void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
 429                                 unsigned long size);
 430 #endif
 431
 432 #ifndef CONFIG_TRANSPARENT_HUGEPAGE
 433 static inline int pmd_trans_huge(pmd_t pmd)
 434 {
 435         return 0;
 436 }
 437 static inline int pmd_trans_splitting(pmd_t pmd)
 438 {
 439         return 0;
 440 }
 441 #ifndef __HAVE_ARCH_PMD_WRITE
 442 static inline int pmd_write(pmd_t pmd)
 443 {
 444         BUG();
 445         return 0;
 446 }
 447 #endif /* __HAVE_ARCH_PMD_WRITE */
 448 #endif
 449
 450 #endif /* !__ASSEMBLY__ */
 451
 452 #endif /* _ASM_GENERIC_PGTABLE_H */