arch/x86/include/asm/pgtable-2level.h

   1 #ifndef _ASM_X86_PGTABLE_2LEVEL_H
   2 #define _ASM_X86_PGTABLE_2LEVEL_H
   3
   4 #define pte_ERROR(e) \
   5         printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, (e).pte_low)
   6 #define pgd_ERROR(e) \
   7         printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
   8
   9 /*
  10  * Certain architectures need to do special things when PTEs
  11  * within a page table are directly modified.  Thus, the following
  12  * hook is made available.
  13  */
  14 static inline void native_set_pte(pte_t *ptep , pte_t pte)
  15 {
  16         *ptep = pte;
  17 }
  18
  19 static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
  20 {
  21         *pmdp = pmd;
  22 }
  23
  24 static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
  25 {
  26         native_set_pte(ptep, pte);
  27 }
  28
  29 static inline void native_pmd_clear(pmd_t *pmdp)
  30 {
  31         native_set_pmd(pmdp, __pmd(0));
  32 }
  33
  34 static inline void native_pte_clear(struct mm_struct *mm,
  35                                     unsigned long addr, pte_t *xp)
  36 {
  37         *xp = native_make_pte(0);
  38 }
  39
  40 #ifdef CONFIG_SMP
  41 static inline pte_t native_ptep_get_and_clear(pte_t *xp)
  42 {
  43         return __pte(xchg(&xp->pte_low, 0));
  44 }
  45 #else
  46 #define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp)
  47 #endif
  48
  49 /*
  50  * Bits _PAGE_BIT_PRESENT, _PAGE_BIT_FILE and _PAGE_BIT_PROTNONE are taken,
  51  * split up the 29 bits of offset into this range:
  52  */
  53 #define PTE_FILE_MAX_BITS       29
  54 #define PTE_FILE_SHIFT1         (_PAGE_BIT_PRESENT + 1)
  55 #if _PAGE_BIT_FILE < _PAGE_BIT_PROTNONE
  56 #define PTE_FILE_SHIFT2         (_PAGE_BIT_FILE + 1)
  57 #define PTE_FILE_SHIFT3         (_PAGE_BIT_PROTNONE + 1)
  58 #else
  59 #define PTE_FILE_SHIFT2         (_PAGE_BIT_PROTNONE + 1)
  60 #define PTE_FILE_SHIFT3         (_PAGE_BIT_FILE + 1)
  61 #endif
  62 #define PTE_FILE_BITS1          (PTE_FILE_SHIFT2 - PTE_FILE_SHIFT1 - 1)
  63 #define PTE_FILE_BITS2          (PTE_FILE_SHIFT3 - PTE_FILE_SHIFT2 - 1)
  64
  65 #define pte_to_pgoff(pte)                                               \
  66         ((((pte).pte_low >> PTE_FILE_SHIFT1)                            \
  67           & ((1U << PTE_FILE_BITS1) - 1))                               \
  68          + ((((pte).pte_low >> PTE_FILE_SHIFT2)                         \
  69              & ((1U << PTE_FILE_BITS2) - 1)) << PTE_FILE_BITS1)         \
  70          + (((pte).pte_low >> PTE_FILE_SHIFT3)                          \
  71             << (PTE_FILE_BITS1 + PTE_FILE_BITS2)))
  72
  73 #define pgoff_to_pte(off)                                               \
  74         ((pte_t) { .pte_low =                                           \
  75          (((off) & ((1U << PTE_FILE_BITS1) - 1)) << PTE_FILE_SHIFT1)    \
  76          + ((((off) >> PTE_FILE_BITS1) & ((1U << PTE_FILE_BITS2) - 1))  \
  77             << PTE_FILE_SHIFT2)                                         \
  78          + (((off) >> (PTE_FILE_BITS1 + PTE_FILE_BITS2))                \
  79             << PTE_FILE_SHIFT3)                                         \
  80          + _PAGE_FILE })
  81
  82 /* Encode and de-code a swap entry */
  83 #if _PAGE_BIT_FILE < _PAGE_BIT_PROTNONE
  84 #define SWP_TYPE_BITS (_PAGE_BIT_FILE - _PAGE_BIT_PRESENT - 1)
  85 #define SWP_OFFSET_SHIFT (_PAGE_BIT_PROTNONE + 1)
  86 #else
  87 #define SWP_TYPE_BITS (_PAGE_BIT_PROTNONE - _PAGE_BIT_PRESENT - 1)
  88 #define SWP_OFFSET_SHIFT (_PAGE_BIT_FILE + 1)
  89 #endif
  90
  91 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
  92
  93 #define __swp_type(x)                   (((x).val >> (_PAGE_BIT_PRESENT + 1)) \
  94                                          & ((1U << SWP_TYPE_BITS) - 1))
  95 #define __swp_offset(x)                 ((x).val >> SWP_OFFSET_SHIFT)
  96 #define __swp_entry(type, offset)       ((swp_entry_t) { \
  97                                          ((type) << (_PAGE_BIT_PRESENT + 1)) \
  98                                          | ((offset) << SWP_OFFSET_SHIFT) })
  99 #define __pte_to_swp_entry(pte)         ((swp_entry_t) { (pte).pte_low })
 100 #define __swp_entry_to_pte(x)           ((pte_t) { .pte = (x).val })
 101
 102 #endif /* _ASM_X86_PGTABLE_2LEVEL_H */