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