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