pgalloc.h (4993B)
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 */ 19static 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 */ 31static 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 */ 42static 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 */ 59static 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 */ 83static 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 */ 99static 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 */ 119static 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 138static 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 150static 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 */ 169static 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 175static 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 182static 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 191static 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 */