LXR linux/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 */
  14static inline void native_set_pte(pte_t *ptep , pte_t pte)
  15{
  16        *ptep = pte;
  17}
  18
  19static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
  20{
  21        *pmdp = pmd;
  22}
  23
  24static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
  25{
  26        native_set_pte(ptep, pte);
  27}
  28
  29static inline void native_pmd_clear(pmd_t *pmdp)
  30{
  31        native_set_pmd(pmdp, __pmd(0));
  32}
  33
  34static 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
  41static 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#ifdef CONFIG_SMP
  50static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
  51{
  52        return __pmd(xchg((pmdval_t *)xp, 0));
  53}
  54#else
  55#define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp)
  56#endif
  57
  58/*
  59 * Bits _PAGE_BIT_PRESENT, _PAGE_BIT_FILE and _PAGE_BIT_PROTNONE are taken,
  60 * split up the 29 bits of offset into this range:
  61 */
  62#define PTE_FILE_MAX_BITS       29
  63#define PTE_FILE_SHIFT1         (_PAGE_BIT_PRESENT + 1)
  64#if _PAGE_BIT_FILE < _PAGE_BIT_PROTNONE
  65#define PTE_FILE_SHIFT2         (_PAGE_BIT_FILE + 1)
  66#define PTE_FILE_SHIFT3         (_PAGE_BIT_PROTNONE + 1)
  67#else
  68#define PTE_FILE_SHIFT2         (_PAGE_BIT_PROTNONE + 1)
  69#define PTE_FILE_SHIFT3         (_PAGE_BIT_FILE + 1)
  70#endif
  71#define PTE_FILE_BITS1          (PTE_FILE_SHIFT2 - PTE_FILE_SHIFT1 - 1)
  72#define PTE_FILE_BITS2          (PTE_FILE_SHIFT3 - PTE_FILE_SHIFT2 - 1)
  73
  74#define pte_to_pgoff(pte)                                               \
  75        ((((pte).pte_low >> PTE_FILE_SHIFT1)                            \
  76          & ((1U << PTE_FILE_BITS1) - 1))                               \
  77         + ((((pte).pte_low >> PTE_FILE_SHIFT2)                         \
  78             & ((1U << PTE_FILE_BITS2) - 1)) << PTE_FILE_BITS1)         \
  79         + (((pte).pte_low >> PTE_FILE_SHIFT3)                          \
  80            << (PTE_FILE_BITS1 + PTE_FILE_BITS2)))
  81
  82#define pgoff_to_pte(off)                                               \
  83        ((pte_t) { .pte_low =                                           \
  84         (((off) & ((1U << PTE_FILE_BITS1) - 1)) << PTE_FILE_SHIFT1)    \
  85         + ((((off) >> PTE_FILE_BITS1) & ((1U << PTE_FILE_BITS2) - 1))  \
  86            << PTE_FILE_SHIFT2)                                         \
  87         + (((off) >> (PTE_FILE_BITS1 + PTE_FILE_BITS2))                \
  88            << PTE_FILE_SHIFT3)                                         \
  89         + _PAGE_FILE })
  90
  91/* Encode and de-code a swap entry */
  92#if _PAGE_BIT_FILE < _PAGE_BIT_PROTNONE
  93#define SWP_TYPE_BITS (_PAGE_BIT_FILE - _PAGE_BIT_PRESENT - 1)
  94#define SWP_OFFSET_SHIFT (_PAGE_BIT_PROTNONE + 1)
  95#else
  96#define SWP_TYPE_BITS (_PAGE_BIT_PROTNONE - _PAGE_BIT_PRESENT - 1)
  97#define SWP_OFFSET_SHIFT (_PAGE_BIT_FILE + 1)
  98#endif
  99
 100#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
 101
 102#define __swp_type(x)                   (((x).val >> (_PAGE_BIT_PRESENT + 1)) \
 103                                         & ((1U << SWP_TYPE_BITS) - 1))
 104#define __swp_offset(x)                 ((x).val >> SWP_OFFSET_SHIFT)
 105#define __swp_entry(type, offset)       ((swp_entry_t) { \
 106                                         ((type) << (_PAGE_BIT_PRESENT + 1)) \
 107                                         | ((offset) << SWP_OFFSET_SHIFT) })
 108#define __pte_to_swp_entry(pte)         ((swp_entry_t) { (pte).pte_low })
 109#define __swp_entry_to_pte(x)           ((pte_t) { .pte = (x).val })
 110
 111#endif /* _ASM_X86_PGTABLE_2LEVEL_H */
 112