xref: /openbmc/linux/arch/x86/include/asm/pgtable-2level.h (revision 2e7c04aec86758e0adfcad4a24c86593b45807a3)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_PGTABLE_2LEVEL_H
3 #define _ASM_X86_PGTABLE_2LEVEL_H
4 
5 #define pte_ERROR(e) \
6 	pr_err("%s:%d: bad pte %08lx\n", __FILE__, __LINE__, (e).pte_low)
7 #define pgd_ERROR(e) \
8 	pr_err("%s:%d: bad pgd %08lx\n", __FILE__, __LINE__, pgd_val(e))
9 
10 /*
11  * Certain architectures need to do special things when PTEs
12  * within a page table are directly modified.  Thus, the following
13  * hook is made available.
14  */
15 static inline void native_set_pte(pte_t *ptep , pte_t pte)
16 {
17 	*ptep = pte;
18 }
19 
20 static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
21 {
22 #ifdef CONFIG_PAGE_TABLE_ISOLATION
23 	pmd.pud.p4d.pgd = pti_set_user_pgtbl(&pmdp->pud.p4d.pgd, pmd.pud.p4d.pgd);
24 #endif
25 	*pmdp = pmd;
26 }
27 
28 static inline void native_set_pud(pud_t *pudp, pud_t pud)
29 {
30 }
31 
32 static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
33 {
34 	native_set_pte(ptep, pte);
35 }
36 
37 static inline void native_pmd_clear(pmd_t *pmdp)
38 {
39 	native_set_pmd(pmdp, __pmd(0));
40 }
41 
42 static inline void native_pud_clear(pud_t *pudp)
43 {
44 }
45 
46 static inline void native_pte_clear(struct mm_struct *mm,
47 				    unsigned long addr, pte_t *xp)
48 {
49 	*xp = native_make_pte(0);
50 }
51 
52 #ifdef CONFIG_SMP
53 static inline pte_t native_ptep_get_and_clear(pte_t *xp)
54 {
55 	return __pte(xchg(&xp->pte_low, 0));
56 }
57 #else
58 #define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp)
59 #endif
60 
61 #ifdef CONFIG_SMP
62 static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
63 {
64 #ifdef CONFIG_PAGE_TABLE_ISOLATION
65 	pti_set_user_pgtbl(&xp->pud.p4d.pgd, __pgd(0));
66 #endif
67 	return __pmd(xchg((pmdval_t *)xp, 0));
68 }
69 #else
70 #define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp)
71 #endif
72 
73 #ifdef CONFIG_SMP
74 static inline pud_t native_pudp_get_and_clear(pud_t *xp)
75 {
76 #ifdef CONFIG_PAGE_TABLE_ISOLATION
77 	pti_set_user_pgtbl(&xp->p4d.pgd, __pgd(0));
78 #endif
79 	return __pud(xchg((pudval_t *)xp, 0));
80 }
81 #else
82 #define native_pudp_get_and_clear(xp) native_local_pudp_get_and_clear(xp)
83 #endif
84 
85 /* Bit manipulation helper on pte/pgoff entry */
86 static inline unsigned long pte_bitop(unsigned long value, unsigned int rightshift,
87 				      unsigned long mask, unsigned int leftshift)
88 {
89 	return ((value >> rightshift) & mask) << leftshift;
90 }
91 
92 /* Encode and de-code a swap entry */
93 #define SWP_TYPE_BITS 5
94 #define SWP_OFFSET_SHIFT (_PAGE_BIT_PROTNONE + 1)
95 
96 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
97 
98 #define __swp_type(x)			(((x).val >> (_PAGE_BIT_PRESENT + 1)) \
99 					 & ((1U << SWP_TYPE_BITS) - 1))
100 #define __swp_offset(x)			((x).val >> SWP_OFFSET_SHIFT)
101 #define __swp_entry(type, offset)	((swp_entry_t) { \
102 					 ((type) << (_PAGE_BIT_PRESENT + 1)) \
103 					 | ((offset) << SWP_OFFSET_SHIFT) })
104 #define __pte_to_swp_entry(pte)		((swp_entry_t) { (pte).pte_low })
105 #define __swp_entry_to_pte(x)		((pte_t) { .pte = (x).val })
106 
107 /* No inverted PFNs on 2 level page tables */
108 
109 static inline u64 protnone_mask(u64 val)
110 {
111 	return 0;
112 }
113 
114 static inline u64 flip_protnone_guard(u64 oldval, u64 val, u64 mask)
115 {
116 	return val;
117 }
118 
119 static inline bool __pte_needs_invert(u64 val)
120 {
121 	return false;
122 }
123 
124 #endif /* _ASM_X86_PGTABLE_2LEVEL_H */
125