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
13static 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)
19static inline void paravirt_pgd_free(struct mm_struct *mm, pgd_t *pgd) {}
20static inline void paravirt_alloc_pte(struct mm_struct *mm, unsigned long pfn) {}
21static inline void paravirt_alloc_pmd(struct mm_struct *mm, unsigned long pfn) {}
22static inline void paravirt_alloc_pmd_clone(unsigned long pfn, unsigned long clonepfn,
23 unsigned long start, unsigned long count) {}
24static inline void paravirt_alloc_pud(struct mm_struct *mm, unsigned long pfn) {}
25static inline void paravirt_alloc_p4d(struct mm_struct *mm, unsigned long pfn) {}
26static inline void paravirt_release_pte(unsigned long pfn) {}
27static inline void paravirt_release_pmd(unsigned long pfn) {}
28static inline void paravirt_release_pud(unsigned long pfn) {}
29static inline void paravirt_release_p4d(unsigned long pfn) {}
30#endif
31
32/*
33 * Flags to use when allocating a user page table page.
34 */
35extern 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 */
51extern pgd_t *pgd_alloc(struct mm_struct *);
52extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
53
54extern pgtable_t pte_alloc_one(struct mm_struct *);
55
56extern void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte);
57
58static 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
64static 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(pmdp: pmd, pmd: __pmd(__pa(pte) | _PAGE_TABLE));
69}
70
71static 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
78static 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(pmdp: pmd, pmd: __pmd(val: ((pteval_t)pfn << PAGE_SHIFT) | _PAGE_TABLE));
85}
86
87#if CONFIG_PGTABLE_LEVELS > 2
88extern void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd);
89
90static 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
97extern void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd);
98#else /* !CONFIG_X86_PAE */
99static 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(pudp: pud, pud: __pud(_PAGE_TABLE | __pa(pmd)));
103}
104
105static 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
113static 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(p4dp: p4d, p4d: __p4d(_PAGE_TABLE | __pa(pud)));
117}
118
119static 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
125extern void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud);
126
127static 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
134static 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
142static 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
150static 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_mask: gfp);
157}
158
159static 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
168extern void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d);
169
170static 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

source code of linux/arch/x86/include/asm/pgalloc.h