1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_PGALLOC_H
3 #define _ASM_X86_PGALLOC_H
4
5 #include <linux/threads.h>
6 #include <linux/mm.h> /* for struct page */
7 #include <linux/pagemap.h>
8
9 #define __HAVE_ARCH_PTE_ALLOC_ONE
10 #define __HAVE_ARCH_PGD_FREE
11 #include <asm-generic/pgalloc.h>
12
13 static inline int __paravirt_pgd_alloc(struct mm_struct *mm) { return 0; }
14
15 #ifdef CONFIG_PARAVIRT_XXL
16 #include <asm/paravirt.h>
17 #else
18 #define paravirt_pgd_alloc(mm) __paravirt_pgd_alloc(mm)
19 static inline void paravirt_pgd_free(struct mm_struct *mm, pgd_t *pgd) {}
20 static inline void paravirt_alloc_pte(struct mm_struct *mm, unsigned long pfn) {}
21 static inline void paravirt_alloc_pmd(struct mm_struct *mm, unsigned long pfn) {}
22 static inline void paravirt_alloc_pmd_clone(unsigned long pfn, unsigned long clonepfn,
23 unsigned long start, unsigned long count) {}
24 static inline void paravirt_alloc_pud(struct mm_struct *mm, unsigned long pfn) {}
25 static inline void paravirt_alloc_p4d(struct mm_struct *mm, unsigned long pfn) {}
26 static inline void paravirt_release_pte(unsigned long pfn) {}
27 static inline void paravirt_release_pmd(unsigned long pfn) {}
28 static inline void paravirt_release_pud(unsigned long pfn) {}
29 static inline void paravirt_release_p4d(unsigned long pfn) {}
30 #endif
31
32 /*
33 * Flags to use when allocating a user page table page.
34 */
35 extern gfp_t __userpte_alloc_gfp;
36
37 #ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
38 /*
39 * Instead of one PGD, we acquire two PGDs. Being order-1, it is
40 * both 8k in size and 8k-aligned. That lets us just flip bit 12
41 * in a pointer to swap between the two 4k halves.
42 */
43 #define PGD_ALLOCATION_ORDER 1
44 #else
45 #define PGD_ALLOCATION_ORDER 0
46 #endif
47
48 /*
49 * Allocate and free page tables.
50 */
51 extern pgd_t *pgd_alloc(struct mm_struct *);
52 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
53
54 extern pgtable_t pte_alloc_one(struct mm_struct *);
55
56 extern void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte);
57
58 static inline void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte,
59 unsigned long address)
60 {
61 ___pte_free_tlb(tlb, pte);
62 }
63
64 static inline void pmd_populate_kernel(struct mm_struct *mm,
65 pmd_t *pmd, pte_t *pte)
66 {
67 paravirt_alloc_pte(mm, __pa(pte) >> PAGE_SHIFT);
68 set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
69 }
70
71 static inline void pmd_populate_kernel_safe(struct mm_struct *mm,
72 pmd_t *pmd, pte_t *pte)
73 {
74 paravirt_alloc_pte(mm, __pa(pte) >> PAGE_SHIFT);
75 set_pmd_safe(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
76 }
77
78 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
79 struct page *pte)
80 {
81 unsigned long pfn = page_to_pfn(pte);
82
83 paravirt_alloc_pte(mm, pfn);
84 set_pmd(pmd, __pmd(((pteval_t)pfn << PAGE_SHIFT) | _PAGE_TABLE));
85 }
86
87 #if CONFIG_PGTABLE_LEVELS > 2
88 extern void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd);
89
90 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
91 unsigned long address)
92 {
93 ___pmd_free_tlb(tlb, pmd);
94 }
95
96 #ifdef CONFIG_X86_PAE
97 extern void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd);
98 #else /* !CONFIG_X86_PAE */
99 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
100 {
101 paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT);
102 set_pud(pud, __pud(_PAGE_TABLE | __pa(pmd)));
103 }
104
105 static inline void pud_populate_safe(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
106 {
107 paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT);
108 set_pud_safe(pud, __pud(_PAGE_TABLE | __pa(pmd)));
109 }
110 #endif /* CONFIG_X86_PAE */
111
112 #if CONFIG_PGTABLE_LEVELS > 3
113 static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
114 {
115 paravirt_alloc_pud(mm, __pa(pud) >> PAGE_SHIFT);
116 set_p4d(p4d, __p4d(_PAGE_TABLE | __pa(pud)));
117 }
118
119 static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
120 {
121 paravirt_alloc_pud(mm, __pa(pud) >> PAGE_SHIFT);
122 set_p4d_safe(p4d, __p4d(_PAGE_TABLE | __pa(pud)));
123 }
124
125 extern void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud);
126
127 static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
128 unsigned long address)
129 {
130 ___pud_free_tlb(tlb, pud);
131 }
132
133 #if CONFIG_PGTABLE_LEVELS > 4
134 static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
135 {
136 if (!pgtable_l5_enabled())
137 return;
138 paravirt_alloc_p4d(mm, __pa(p4d) >> PAGE_SHIFT);
139 set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(p4d)));
140 }
141
142 static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
143 {
144 if (!pgtable_l5_enabled())
145 return;
146 paravirt_alloc_p4d(mm, __pa(p4d) >> PAGE_SHIFT);
147 set_pgd_safe(pgd, __pgd(_PAGE_TABLE | __pa(p4d)));
148 }
149
150 static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
151 {
152 gfp_t gfp = GFP_KERNEL_ACCOUNT;
153
154 if (mm == &init_mm)
155 gfp &= ~__GFP_ACCOUNT;
156 return (p4d_t *)get_zeroed_page(gfp);
157 }
158
159 static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
160 {
161 if (!pgtable_l5_enabled())
162 return;
163
164 BUG_ON((unsigned long)p4d & (PAGE_SIZE-1));
165 free_page((unsigned long)p4d);
166 }
167
168 extern void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d);
169
170 static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
171 unsigned long address)
172 {
173 if (pgtable_l5_enabled())
174 ___p4d_free_tlb(tlb, p4d);
175 }
176
177 #endif /* CONFIG_PGTABLE_LEVELS > 4 */
178 #endif /* CONFIG_PGTABLE_LEVELS > 3 */
179 #endif /* CONFIG_PGTABLE_LEVELS > 2 */
180
181 #endif /* _ASM_X86_PGALLOC_H */
182
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