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_noprof(struct mm_struct * mm)19 static inline pte_t *__pte_alloc_one_kernel_noprof(struct mm_struct *mm)
20 {
21 struct ptdesc *ptdesc = pagetable_alloc_noprof(GFP_PGTABLE_KERNEL &
22 ~__GFP_HIGHMEM, 0);
23
24 if (!ptdesc)
25 return NULL;
26 return ptdesc_address(ptdesc);
27 }
28 #define __pte_alloc_one_kernel(...) alloc_hooks(__pte_alloc_one_kernel_noprof(__VA_ARGS__))
29
30 #ifndef __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
31 /**
32 * pte_alloc_one_kernel - allocate memory for a PTE-level kernel page table
33 * @mm: the mm_struct of the current context
34 *
35 * Return: pointer to the allocated memory or %NULL on error
36 */
pte_alloc_one_kernel_noprof(struct mm_struct * mm)37 static inline pte_t *pte_alloc_one_kernel_noprof(struct mm_struct *mm)
38 {
39 return __pte_alloc_one_kernel_noprof(mm);
40 }
41 #define pte_alloc_one_kernel(...) alloc_hooks(pte_alloc_one_kernel_noprof(__VA_ARGS__))
42 #endif
43
44 /**
45 * pte_free_kernel - free PTE-level kernel page table memory
46 * @mm: the mm_struct of the current context
47 * @pte: pointer to the memory containing the page table
48 */
pte_free_kernel(struct mm_struct * mm,pte_t * pte)49 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
50 {
51 pagetable_free(virt_to_ptdesc(pte));
52 }
53
54 /**
55 * __pte_alloc_one - allocate memory for a PTE-level user page table
56 * @mm: the mm_struct of the current context
57 * @gfp: GFP flags to use for the allocation
58 *
59 * Allocate memory for a page table and ptdesc and runs pagetable_pte_ctor().
60 *
61 * This function is intended for architectures that need
62 * anything beyond simple page allocation or must have custom GFP flags.
63 *
64 * Return: `struct page` referencing the ptdesc or %NULL on error
65 */
__pte_alloc_one_noprof(struct mm_struct * mm,gfp_t gfp)66 static inline pgtable_t __pte_alloc_one_noprof(struct mm_struct *mm, gfp_t gfp)
67 {
68 struct ptdesc *ptdesc;
69
70 ptdesc = pagetable_alloc_noprof(gfp, 0);
71 if (!ptdesc)
72 return NULL;
73 if (!pagetable_pte_ctor(ptdesc)) {
74 pagetable_free(ptdesc);
75 return NULL;
76 }
77
78 return ptdesc_page(ptdesc);
79 }
80 #define __pte_alloc_one(...) alloc_hooks(__pte_alloc_one_noprof(__VA_ARGS__))
81
82 #ifndef __HAVE_ARCH_PTE_ALLOC_ONE
83 /**
84 * pte_alloc_one - allocate a page for PTE-level user page table
85 * @mm: the mm_struct of the current context
86 *
87 * Allocate memory for a page table and ptdesc and runs pagetable_pte_ctor().
88 *
89 * Return: `struct page` referencing the ptdesc or %NULL on error
90 */
pte_alloc_one_noprof(struct mm_struct * mm)91 static inline pgtable_t pte_alloc_one_noprof(struct mm_struct *mm)
92 {
93 return __pte_alloc_one_noprof(mm, GFP_PGTABLE_USER);
94 }
95 #define pte_alloc_one(...) alloc_hooks(pte_alloc_one_noprof(__VA_ARGS__))
96 #endif
97
98 /*
99 * Should really implement gc for free page table pages. This could be
100 * done with a reference count in struct page.
101 */
102
103 /**
104 * pte_free - free PTE-level user page table memory
105 * @mm: the mm_struct of the current context
106 * @pte_page: the `struct page` referencing the ptdesc
107 */
pte_free(struct mm_struct * mm,struct page * pte_page)108 static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
109 {
110 struct ptdesc *ptdesc = page_ptdesc(pte_page);
111
112 pagetable_pte_dtor(ptdesc);
113 pagetable_free(ptdesc);
114 }
115
116
117 #if CONFIG_PGTABLE_LEVELS > 2
118
119 #ifndef __HAVE_ARCH_PMD_ALLOC_ONE
120 /**
121 * pmd_alloc_one - allocate memory for a PMD-level page table
122 * @mm: the mm_struct of the current context
123 *
124 * Allocate memory for a page table and ptdesc and runs pagetable_pmd_ctor().
125 *
126 * Allocations use %GFP_PGTABLE_USER in user context and
127 * %GFP_PGTABLE_KERNEL in kernel context.
128 *
129 * Return: pointer to the allocated memory or %NULL on error
130 */
pmd_alloc_one_noprof(struct mm_struct * mm,unsigned long addr)131 static inline pmd_t *pmd_alloc_one_noprof(struct mm_struct *mm, unsigned long addr)
132 {
133 struct ptdesc *ptdesc;
134 gfp_t gfp = GFP_PGTABLE_USER;
135
136 if (mm == &init_mm)
137 gfp = GFP_PGTABLE_KERNEL;
138 ptdesc = pagetable_alloc_noprof(gfp, 0);
139 if (!ptdesc)
140 return NULL;
141 if (!pagetable_pmd_ctor(ptdesc)) {
142 pagetable_free(ptdesc);
143 return NULL;
144 }
145 return ptdesc_address(ptdesc);
146 }
147 #define pmd_alloc_one(...) alloc_hooks(pmd_alloc_one_noprof(__VA_ARGS__))
148 #endif
149
150 #ifndef __HAVE_ARCH_PMD_FREE
pmd_free(struct mm_struct * mm,pmd_t * pmd)151 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
152 {
153 struct ptdesc *ptdesc = virt_to_ptdesc(pmd);
154
155 BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
156 pagetable_pmd_dtor(ptdesc);
157 pagetable_free(ptdesc);
158 }
159 #endif
160
161 #endif /* CONFIG_PGTABLE_LEVELS > 2 */
162
163 #if CONFIG_PGTABLE_LEVELS > 3
164
__pud_alloc_one_noprof(struct mm_struct * mm,unsigned long addr)165 static inline pud_t *__pud_alloc_one_noprof(struct mm_struct *mm, unsigned long addr)
166 {
167 gfp_t gfp = GFP_PGTABLE_USER;
168 struct ptdesc *ptdesc;
169
170 if (mm == &init_mm)
171 gfp = GFP_PGTABLE_KERNEL;
172 gfp &= ~__GFP_HIGHMEM;
173
174 ptdesc = pagetable_alloc_noprof(gfp, 0);
175 if (!ptdesc)
176 return NULL;
177
178 pagetable_pud_ctor(ptdesc);
179 return ptdesc_address(ptdesc);
180 }
181 #define __pud_alloc_one(...) alloc_hooks(__pud_alloc_one_noprof(__VA_ARGS__))
182
183 #ifndef __HAVE_ARCH_PUD_ALLOC_ONE
184 /**
185 * pud_alloc_one - allocate memory for a PUD-level page table
186 * @mm: the mm_struct of the current context
187 *
188 * Allocate memory for a page table using %GFP_PGTABLE_USER for user context
189 * and %GFP_PGTABLE_KERNEL for kernel context.
190 *
191 * Return: pointer to the allocated memory or %NULL on error
192 */
pud_alloc_one_noprof(struct mm_struct * mm,unsigned long addr)193 static inline pud_t *pud_alloc_one_noprof(struct mm_struct *mm, unsigned long addr)
194 {
195 return __pud_alloc_one_noprof(mm, addr);
196 }
197 #define pud_alloc_one(...) alloc_hooks(pud_alloc_one_noprof(__VA_ARGS__))
198 #endif
199
__pud_free(struct mm_struct * mm,pud_t * pud)200 static inline void __pud_free(struct mm_struct *mm, pud_t *pud)
201 {
202 struct ptdesc *ptdesc = virt_to_ptdesc(pud);
203
204 BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
205 pagetable_pud_dtor(ptdesc);
206 pagetable_free(ptdesc);
207 }
208
209 #ifndef __HAVE_ARCH_PUD_FREE
pud_free(struct mm_struct * mm,pud_t * pud)210 static inline void pud_free(struct mm_struct *mm, pud_t *pud)
211 {
212 __pud_free(mm, pud);
213 }
214 #endif
215
216 #endif /* CONFIG_PGTABLE_LEVELS > 3 */
217
218 #ifndef __HAVE_ARCH_PGD_FREE
pgd_free(struct mm_struct * mm,pgd_t * pgd)219 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
220 {
221 pagetable_free(virt_to_ptdesc(pgd));
222 }
223 #endif
224
225 #endif /* CONFIG_MMU */
226
227 #endif /* __ASM_GENERIC_PGALLOC_H */
228