xref: /linux/include/asm-generic/pgalloc.h (revision af8e51644a70f612974a6e767fa7d896d3c23f88)
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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
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 
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  */
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 
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
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
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