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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/*
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 */