include/asm-x86/pgtable-3level.h

   1 #ifndef _I386_PGTABLE_3LEVEL_H
   2 #define _I386_PGTABLE_3LEVEL_H
   3
   4 /*
   5  * Intel Physical Address Extension (PAE) Mode - three-level page
   6  * tables on PPro+ CPUs.
   7  *
   8  * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
   9  */
  10
  11 #define pte_ERROR(e) \
  12         printk("%s:%d: bad pte %p(%08lx%08lx).\n", __FILE__, __LINE__, &(e), (e).pte_high, (e).pte_low)
  13 #define pmd_ERROR(e) \
  14         printk("%s:%d: bad pmd %p(%016Lx).\n", __FILE__, __LINE__, &(e), pmd_val(e))
  15 #define pgd_ERROR(e) \
  16         printk("%s:%d: bad pgd %p(%016Lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))
  17
  18
  19 static inline int pud_none(pud_t pud)
  20 {
  21         return pud_val(pud) == 0;
  22 }
  23 static inline int pud_bad(pud_t pud)
  24 {
  25         return (pud_val(pud) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER)) != 0;
  26 }
  27 static inline int pud_present(pud_t pud)
  28 {
  29         return pud_val(pud) & _PAGE_PRESENT;
  30 }
  31
  32 /* Rules for using set_pte: the pte being assigned *must* be
  33  * either not present or in a state where the hardware will
  34  * not attempt to update the pte.  In places where this is
  35  * not possible, use pte_get_and_clear to obtain the old pte
  36  * value and then use set_pte to update it.  -ben
  37  */
  38 static inline void native_set_pte(pte_t *ptep, pte_t pte)
  39 {
  40         ptep->pte_high = pte.pte_high;
  41         smp_wmb();
  42         ptep->pte_low = pte.pte_low;
  43 }
  44
  45 /*
  46  * Since this is only called on user PTEs, and the page fault handler
  47  * must handle the already racy situation of simultaneous page faults,
  48  * we are justified in merely clearing the PTE present bit, followed
  49  * by a set.  The ordering here is important.
  50  */
  51 static inline void native_set_pte_present(struct mm_struct *mm, unsigned long addr,
  52                                           pte_t *ptep, pte_t pte)
  53 {
  54         ptep->pte_low = 0;
  55         smp_wmb();
  56         ptep->pte_high = pte.pte_high;
  57         smp_wmb();
  58         ptep->pte_low = pte.pte_low;
  59 }
  60
  61 static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
  62 {
  63         set_64bit((unsigned long long *)(ptep),native_pte_val(pte));
  64 }
  65 static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
  66 {
  67         set_64bit((unsigned long long *)(pmdp),native_pmd_val(pmd));
  68 }
  69 static inline void native_set_pud(pud_t *pudp, pud_t pud)
  70 {
  71         set_64bit((unsigned long long *)(pudp),native_pud_val(pud));
  72 }
  73
  74 /*
  75  * For PTEs and PDEs, we must clear the P-bit first when clearing a page table
  76  * entry, so clear the bottom half first and enforce ordering with a compiler
  77  * barrier.
  78  */
  79 static inline void native_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
  80 {
  81         ptep->pte_low = 0;
  82         smp_wmb();
  83         ptep->pte_high = 0;
  84 }
  85
  86 static inline void native_pmd_clear(pmd_t *pmd)
  87 {
  88         u32 *tmp = (u32 *)pmd;
  89         *tmp = 0;
  90         smp_wmb();
  91         *(tmp + 1) = 0;
  92 }
  93
  94 static inline void pud_clear(pud_t *pudp)
  95 {
  96         set_pud(pudp, __pud(0));
  97
  98         /*
  99          * In principle we need to do a cr3 reload here to make sure
 100          * the processor recognizes the changed pgd.  In practice, all
 101          * the places where pud_clear() gets called are followed by
 102          * full tlb flushes anyway, so we can defer the cost here.
 103          *
 104          * Specifically:
 105          *
 106          * mm/memory.c:free_pmd_range() - immediately after the
 107          * pud_clear() it does a pmd_free_tlb().  We change the
 108          * mmu_gather structure to do a full tlb flush (which has the
 109          * effect of reloading cr3) when the pagetable free is
 110          * complete.
 111          *
 112          * arch/x86/mm/hugetlbpage.c:huge_pmd_unshare() - the call to
 113          * this is followed by a flush_tlb_range, which on x86 does a
 114          * full tlb flush.
 115          */
 116 }
 117
 118 #define pud_page(pud) \
 119 ((struct page *) __va(pud_val(pud) & PAGE_MASK))
 120
 121 #define pud_page_vaddr(pud) \
 122 ((unsigned long) __va(pud_val(pud) & PAGE_MASK))
 123
 124
 125 /* Find an entry in the second-level page table.. */
 126 #define pmd_offset(pud, address) ((pmd_t *) pud_page(*(pud)) + \
 127                         pmd_index(address))
 128
 129 #ifdef CONFIG_SMP
 130 static inline pte_t native_ptep_get_and_clear(pte_t *ptep)
 131 {
 132         pte_t res;
 133
 134         /* xchg acts as a barrier before the setting of the high bits */
 135         res.pte_low = xchg(&ptep->pte_low, 0);
 136         res.pte_high = ptep->pte_high;
 137         ptep->pte_high = 0;
 138
 139         return res;
 140 }
 141 #else
 142 #define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp)
 143 #endif
 144
 145 #define __HAVE_ARCH_PTE_SAME
 146 static inline int pte_same(pte_t a, pte_t b)
 147 {
 148         return a.pte_low == b.pte_low && a.pte_high == b.pte_high;
 149 }
 150
 151 #define pte_page(x)     pfn_to_page(pte_pfn(x))
 152
 153 static inline int pte_none(pte_t pte)
 154 {
 155         return !pte.pte_low && !pte.pte_high;
 156 }
 157
 158 static inline unsigned long pte_pfn(pte_t pte)
 159 {
 160         return (pte_val(pte) & ~_PAGE_NX) >> PAGE_SHIFT;
 161 }
 162
 163 /*
 164  * Bits 0, 6 and 7 are taken in the low part of the pte,
 165  * put the 32 bits of offset into the high part.
 166  */
 167 #define pte_to_pgoff(pte) ((pte).pte_high)
 168 #define pgoff_to_pte(off) ((pte_t) { { .pte_low = _PAGE_FILE, .pte_high = (off) } })
 169 #define PTE_FILE_MAX_BITS       32
 170
 171 /* Encode and de-code a swap entry */
 172 #define __swp_type(x)                   (((x).val) & 0x1f)
 173 #define __swp_offset(x)                 ((x).val >> 5)
 174 #define __swp_entry(type, offset)       ((swp_entry_t){(type) | (offset) << 5})
 175 #define __pte_to_swp_entry(pte)         ((swp_entry_t){ (pte).pte_high })
 176 #define __swp_entry_to_pte(x)           ((pte_t){ { .pte_high = (x).val } })
 177
 178 #endif /* _I386_PGTABLE_3LEVEL_H */