xref: /linux/arch/x86/include/asm/pgalloc.h (revision bab2c80e5a6c855657482eac9e97f5f3eedb509a)
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 static inline int  __paravirt_pgd_alloc(struct mm_struct *mm) { return 0; }
10 
11 #ifdef CONFIG_PARAVIRT
12 #include <asm/paravirt.h>
13 #else
14 #define paravirt_pgd_alloc(mm)	__paravirt_pgd_alloc(mm)
15 static inline void paravirt_pgd_free(struct mm_struct *mm, pgd_t *pgd) {}
16 static inline void paravirt_alloc_pte(struct mm_struct *mm, unsigned long pfn)	{}
17 static inline void paravirt_alloc_pmd(struct mm_struct *mm, unsigned long pfn)	{}
18 static inline void paravirt_alloc_pmd_clone(unsigned long pfn, unsigned long clonepfn,
19 					    unsigned long start, unsigned long count) {}
20 static inline void paravirt_alloc_pud(struct mm_struct *mm, unsigned long pfn)	{}
21 static inline void paravirt_alloc_p4d(struct mm_struct *mm, unsigned long pfn)	{}
22 static inline void paravirt_release_pte(unsigned long pfn) {}
23 static inline void paravirt_release_pmd(unsigned long pfn) {}
24 static inline void paravirt_release_pud(unsigned long pfn) {}
25 static inline void paravirt_release_p4d(unsigned long pfn) {}
26 #endif
27 
28 /*
29  * Flags to use when allocating a user page table page.
30  */
31 extern gfp_t __userpte_alloc_gfp;
32 
33 #ifdef CONFIG_PAGE_TABLE_ISOLATION
34 /*
35  * Instead of one PGD, we acquire two PGDs.  Being order-1, it is
36  * both 8k in size and 8k-aligned.  That lets us just flip bit 12
37  * in a pointer to swap between the two 4k halves.
38  */
39 #define PGD_ALLOCATION_ORDER 1
40 #else
41 #define PGD_ALLOCATION_ORDER 0
42 #endif
43 
44 /*
45  * Allocate and free page tables.
46  */
47 extern pgd_t *pgd_alloc(struct mm_struct *);
48 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
49 
50 extern pte_t *pte_alloc_one_kernel(struct mm_struct *, unsigned long);
51 extern pgtable_t pte_alloc_one(struct mm_struct *, unsigned long);
52 
53 /* Should really implement gc for free page table pages. This could be
54    done with a reference count in struct page. */
55 
56 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
57 {
58 	BUG_ON((unsigned long)pte & (PAGE_SIZE-1));
59 	free_page((unsigned long)pte);
60 }
61 
62 static inline void pte_free(struct mm_struct *mm, struct page *pte)
63 {
64 	pgtable_page_dtor(pte);
65 	__free_page(pte);
66 }
67 
68 extern void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte);
69 
70 static inline void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte,
71 				  unsigned long address)
72 {
73 	___pte_free_tlb(tlb, pte);
74 }
75 
76 static inline void pmd_populate_kernel(struct mm_struct *mm,
77 				       pmd_t *pmd, pte_t *pte)
78 {
79 	paravirt_alloc_pte(mm, __pa(pte) >> PAGE_SHIFT);
80 	set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
81 }
82 
83 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
84 				struct page *pte)
85 {
86 	unsigned long pfn = page_to_pfn(pte);
87 
88 	paravirt_alloc_pte(mm, pfn);
89 	set_pmd(pmd, __pmd(((pteval_t)pfn << PAGE_SHIFT) | _PAGE_TABLE));
90 }
91 
92 #define pmd_pgtable(pmd) pmd_page(pmd)
93 
94 #if CONFIG_PGTABLE_LEVELS > 2
95 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
96 {
97 	struct page *page;
98 	gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO;
99 
100 	if (mm == &init_mm)
101 		gfp &= ~__GFP_ACCOUNT;
102 	page = alloc_pages(gfp, 0);
103 	if (!page)
104 		return NULL;
105 	if (!pgtable_pmd_page_ctor(page)) {
106 		__free_pages(page, 0);
107 		return NULL;
108 	}
109 	return (pmd_t *)page_address(page);
110 }
111 
112 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
113 {
114 	BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
115 	pgtable_pmd_page_dtor(virt_to_page(pmd));
116 	free_page((unsigned long)pmd);
117 }
118 
119 extern void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd);
120 
121 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
122 				  unsigned long address)
123 {
124 	___pmd_free_tlb(tlb, pmd);
125 }
126 
127 #ifdef CONFIG_X86_PAE
128 extern void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd);
129 #else	/* !CONFIG_X86_PAE */
130 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
131 {
132 	paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT);
133 	set_pud(pud, __pud(_PAGE_TABLE | __pa(pmd)));
134 }
135 #endif	/* CONFIG_X86_PAE */
136 
137 #if CONFIG_PGTABLE_LEVELS > 3
138 static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
139 {
140 	paravirt_alloc_pud(mm, __pa(pud) >> PAGE_SHIFT);
141 	set_p4d(p4d, __p4d(_PAGE_TABLE | __pa(pud)));
142 }
143 
144 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
145 {
146 	gfp_t gfp = GFP_KERNEL_ACCOUNT;
147 
148 	if (mm == &init_mm)
149 		gfp &= ~__GFP_ACCOUNT;
150 	return (pud_t *)get_zeroed_page(gfp);
151 }
152 
153 static inline void pud_free(struct mm_struct *mm, pud_t *pud)
154 {
155 	BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
156 	free_page((unsigned long)pud);
157 }
158 
159 extern void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud);
160 
161 static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
162 				  unsigned long address)
163 {
164 	___pud_free_tlb(tlb, pud);
165 }
166 
167 #if CONFIG_PGTABLE_LEVELS > 4
168 static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
169 {
170 	if (!pgtable_l5_enabled())
171 		return;
172 	paravirt_alloc_p4d(mm, __pa(p4d) >> PAGE_SHIFT);
173 	set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(p4d)));
174 }
175 
176 static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
177 {
178 	gfp_t gfp = GFP_KERNEL_ACCOUNT;
179 
180 	if (mm == &init_mm)
181 		gfp &= ~__GFP_ACCOUNT;
182 	return (p4d_t *)get_zeroed_page(gfp);
183 }
184 
185 static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
186 {
187 	if (!pgtable_l5_enabled())
188 		return;
189 
190 	BUG_ON((unsigned long)p4d & (PAGE_SIZE-1));
191 	free_page((unsigned long)p4d);
192 }
193 
194 extern void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d);
195 
196 static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
197 				  unsigned long address)
198 {
199 	if (pgtable_l5_enabled())
200 		___p4d_free_tlb(tlb, p4d);
201 }
202 
203 #endif	/* CONFIG_PGTABLE_LEVELS > 4 */
204 #endif	/* CONFIG_PGTABLE_LEVELS > 3 */
205 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
206 
207 #endif /* _ASM_X86_PGALLOC_H */
208