1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_GENERIC_PGALLOC_H
3 #define __ASM_GENERIC_PGALLOC_H
4
5 #ifdef CONFIG_MMU
6
7 #define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO)
8 #define GFP_PGTABLE_USER (GFP_PGTABLE_KERNEL | __GFP_ACCOUNT)
9
10 /**
11 * __pte_alloc_one_kernel - allocate memory for a PTE-level kernel page table
12 * @mm: the mm_struct of the current context
13 *
14 * This function is intended for architectures that need
15 * anything beyond simple page allocation.
16 *
17 * Return: pointer to the allocated memory or %NULL on error
18 */
__pte_alloc_one_kernel(struct mm_struct * mm)19 static inline pte_t *__pte_alloc_one_kernel(struct mm_struct *mm)
20 {
21 struct ptdesc *ptdesc = pagetable_alloc(GFP_PGTABLE_KERNEL &
22 ~__GFP_HIGHMEM, 0);
23
24 if (!ptdesc)
25 return NULL;
26 return ptdesc_address(ptdesc);
27 }
28
29 #ifndef __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
30 /**
31 * pte_alloc_one_kernel - allocate memory for a PTE-level kernel page table
32 * @mm: the mm_struct of the current context
33 *
34 * Return: pointer to the allocated memory or %NULL on error
35 */
pte_alloc_one_kernel(struct mm_struct * mm)36 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
37 {
38 return __pte_alloc_one_kernel(mm);
39 }
40 #endif
41
42 /**
43 * pte_free_kernel - free PTE-level kernel page table memory
44 * @mm: the mm_struct of the current context
45 * @pte: pointer to the memory containing the page table
46 */
pte_free_kernel(struct mm_struct * mm,pte_t * pte)47 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
48 {
49 pagetable_free(virt_to_ptdesc(pte));
50 }
51
52 /**
53 * __pte_alloc_one - allocate memory for a PTE-level user page table
54 * @mm: the mm_struct of the current context
55 * @gfp: GFP flags to use for the allocation
56 *
57 * Allocate memory for a page table and ptdesc and runs pagetable_pte_ctor().
58 *
59 * This function is intended for architectures that need
60 * anything beyond simple page allocation or must have custom GFP flags.
61 *
62 * Return: `struct page` referencing the ptdesc or %NULL on error
63 */
__pte_alloc_one(struct mm_struct * mm,gfp_t gfp)64 static inline pgtable_t __pte_alloc_one(struct mm_struct *mm, gfp_t gfp)
65 {
66 struct ptdesc *ptdesc;
67
68 ptdesc = pagetable_alloc(gfp, 0);
69 if (!ptdesc)
70 return NULL;
71 if (!pagetable_pte_ctor(ptdesc)) {
72 pagetable_free(ptdesc);
73 return NULL;
74 }
75
76 return ptdesc_page(ptdesc);
77 }
78
79 #ifndef __HAVE_ARCH_PTE_ALLOC_ONE
80 /**
81 * pte_alloc_one - allocate a page for PTE-level user page table
82 * @mm: the mm_struct of the current context
83 *
84 * Allocate memory for a page table and ptdesc and runs pagetable_pte_ctor().
85 *
86 * Return: `struct page` referencing the ptdesc or %NULL on error
87 */
pte_alloc_one(struct mm_struct * mm)88 static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
89 {
90 return __pte_alloc_one(mm, GFP_PGTABLE_USER);
91 }
92 #endif
93
94 /*
95 * Should really implement gc for free page table pages. This could be
96 * done with a reference count in struct page.
97 */
98
99 /**
100 * pte_free - free PTE-level user page table memory
101 * @mm: the mm_struct of the current context
102 * @pte_page: the `struct page` referencing the ptdesc
103 */
pte_free(struct mm_struct * mm,struct page * pte_page)104 static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
105 {
106 struct ptdesc *ptdesc = page_ptdesc(pte_page);
107
108 pagetable_pte_dtor(ptdesc);
109 pagetable_free(ptdesc);
110 }
111
112
113 #if CONFIG_PGTABLE_LEVELS > 2
114
115 #ifndef __HAVE_ARCH_PMD_ALLOC_ONE
116 /**
117 * pmd_alloc_one - allocate memory for a PMD-level page table
118 * @mm: the mm_struct of the current context
119 *
120 * Allocate memory for a page table and ptdesc and runs pagetable_pmd_ctor().
121 *
122 * Allocations use %GFP_PGTABLE_USER in user context and
123 * %GFP_PGTABLE_KERNEL in kernel context.
124 *
125 * Return: pointer to the allocated memory or %NULL on error
126 */
pmd_alloc_one(struct mm_struct * mm,unsigned long addr)127 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
128 {
129 struct ptdesc *ptdesc;
130 gfp_t gfp = GFP_PGTABLE_USER;
131
132 if (mm == &init_mm)
133 gfp = GFP_PGTABLE_KERNEL;
134 ptdesc = pagetable_alloc(gfp, 0);
135 if (!ptdesc)
136 return NULL;
137 if (!pagetable_pmd_ctor(ptdesc)) {
138 pagetable_free(ptdesc);
139 return NULL;
140 }
141 return ptdesc_address(ptdesc);
142 }
143 #endif
144
145 #ifndef __HAVE_ARCH_PMD_FREE
pmd_free(struct mm_struct * mm,pmd_t * pmd)146 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
147 {
148 struct ptdesc *ptdesc = virt_to_ptdesc(pmd);
149
150 BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
151 pagetable_pmd_dtor(ptdesc);
152 pagetable_free(ptdesc);
153 }
154 #endif
155
156 #endif /* CONFIG_PGTABLE_LEVELS > 2 */
157
158 #if CONFIG_PGTABLE_LEVELS > 3
159
__pud_alloc_one(struct mm_struct * mm,unsigned long addr)160 static inline pud_t *__pud_alloc_one(struct mm_struct *mm, unsigned long addr)
161 {
162 gfp_t gfp = GFP_PGTABLE_USER;
163 struct ptdesc *ptdesc;
164
165 if (mm == &init_mm)
166 gfp = GFP_PGTABLE_KERNEL;
167 gfp &= ~__GFP_HIGHMEM;
168
169 ptdesc = pagetable_alloc(gfp, 0);
170 if (!ptdesc)
171 return NULL;
172 return ptdesc_address(ptdesc);
173 }
174
175 #ifndef __HAVE_ARCH_PUD_ALLOC_ONE
176 /**
177 * pud_alloc_one - allocate memory for a PUD-level page table
178 * @mm: the mm_struct of the current context
179 *
180 * Allocate memory for a page table using %GFP_PGTABLE_USER for user context
181 * and %GFP_PGTABLE_KERNEL for kernel context.
182 *
183 * Return: pointer to the allocated memory or %NULL on error
184 */
pud_alloc_one(struct mm_struct * mm,unsigned long addr)185 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
186 {
187 return __pud_alloc_one(mm, addr);
188 }
189 #endif
190
__pud_free(struct mm_struct * mm,pud_t * pud)191 static inline void __pud_free(struct mm_struct *mm, pud_t *pud)
192 {
193 BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
194 pagetable_free(virt_to_ptdesc(pud));
195 }
196
197 #ifndef __HAVE_ARCH_PUD_FREE
pud_free(struct mm_struct * mm,pud_t * pud)198 static inline void pud_free(struct mm_struct *mm, pud_t *pud)
199 {
200 __pud_free(mm, pud);
201 }
202 #endif
203
204 #endif /* CONFIG_PGTABLE_LEVELS > 3 */
205
206 #ifndef __HAVE_ARCH_PGD_FREE
pgd_free(struct mm_struct * mm,pgd_t * pgd)207 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
208 {
209 pagetable_free(virt_to_ptdesc(pgd));
210 }
211 #endif
212
213 #endif /* CONFIG_MMU */
214
215 #endif /* __ASM_GENERIC_PGALLOC_H */
216