1 #ifndef _ASM_X86_PGTABLE_2LEVEL_H
2 #define _ASM_X86_PGTABLE_2LEVEL_H
3 
4 #define pte_ERROR(e) \
5 	pr_err("%s:%d: bad pte %08lx\n", __FILE__, __LINE__, (e).pte_low)
6 #define pgd_ERROR(e) \
7 	pr_err("%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 #ifdef CONFIG_SMP
50 static 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