1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * arch/arm/include/asm/pgalloc.h 4 * 5 * Copyright (C) 2000-2001 Russell King 6 */ 7 #ifndef _ASMARM_PGALLOC_H 8 #define _ASMARM_PGALLOC_H 9 10 #include <linux/pagemap.h> 11 12 #include <asm/domain.h> 13 #include <asm/pgtable-hwdef.h> 14 #include <asm/processor.h> 15 #include <asm/cacheflush.h> 16 #include <asm/tlbflush.h> 17 18 #define check_pgt_cache() do { } while (0) 19 20 #ifdef CONFIG_MMU 21 22 #define _PAGE_USER_TABLE (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER)) 23 #define _PAGE_KERNEL_TABLE (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL)) 24 25 #ifdef CONFIG_ARM_LPAE 26 27 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr) 28 { 29 return (pmd_t *)get_zeroed_page(GFP_KERNEL); 30 } 31 32 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd) 33 { 34 BUG_ON((unsigned long)pmd & (PAGE_SIZE-1)); 35 free_page((unsigned long)pmd); 36 } 37 38 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd) 39 { 40 set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE)); 41 } 42 43 #else /* !CONFIG_ARM_LPAE */ 44 45 /* 46 * Since we have only two-level page tables, these are trivial 47 */ 48 #define pmd_alloc_one(mm,addr) ({ BUG(); ((pmd_t *)2); }) 49 #define pmd_free(mm, pmd) do { } while (0) 50 #define pud_populate(mm,pmd,pte) BUG() 51 52 #endif /* CONFIG_ARM_LPAE */ 53 54 extern pgd_t *pgd_alloc(struct mm_struct *mm); 55 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd); 56 57 #define PGALLOC_GFP (GFP_KERNEL | __GFP_ZERO) 58 59 static inline void clean_pte_table(pte_t *pte) 60 { 61 clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE); 62 } 63 64 /* 65 * Allocate one PTE table. 66 * 67 * This actually allocates two hardware PTE tables, but we wrap this up 68 * into one table thus: 69 * 70 * +------------+ 71 * | Linux pt 0 | 72 * +------------+ 73 * | Linux pt 1 | 74 * +------------+ 75 * | h/w pt 0 | 76 * +------------+ 77 * | h/w pt 1 | 78 * +------------+ 79 */ 80 static inline pte_t * 81 pte_alloc_one_kernel(struct mm_struct *mm) 82 { 83 pte_t *pte; 84 85 pte = (pte_t *)__get_free_page(PGALLOC_GFP); 86 if (pte) 87 clean_pte_table(pte); 88 89 return pte; 90 } 91 92 static inline pgtable_t 93 pte_alloc_one(struct mm_struct *mm) 94 { 95 struct page *pte; 96 97 #ifdef CONFIG_HIGHPTE 98 pte = alloc_pages(PGALLOC_GFP | __GFP_HIGHMEM, 0); 99 #else 100 pte = alloc_pages(PGALLOC_GFP, 0); 101 #endif 102 if (!pte) 103 return NULL; 104 if (!PageHighMem(pte)) 105 clean_pte_table(page_address(pte)); 106 if (!pgtable_page_ctor(pte)) { 107 __free_page(pte); 108 return NULL; 109 } 110 return pte; 111 } 112 113 /* 114 * Free one PTE table. 115 */ 116 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte) 117 { 118 if (pte) 119 free_page((unsigned long)pte); 120 } 121 122 static inline void pte_free(struct mm_struct *mm, pgtable_t pte) 123 { 124 pgtable_page_dtor(pte); 125 __free_page(pte); 126 } 127 128 static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte, 129 pmdval_t prot) 130 { 131 pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot; 132 pmdp[0] = __pmd(pmdval); 133 #ifndef CONFIG_ARM_LPAE 134 pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t)); 135 #endif 136 flush_pmd_entry(pmdp); 137 } 138 139 /* 140 * Populate the pmdp entry with a pointer to the pte. This pmd is part 141 * of the mm address space. 142 * 143 * Ensure that we always set both PMD entries. 144 */ 145 static inline void 146 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep) 147 { 148 /* 149 * The pmd must be loaded with the physical address of the PTE table 150 */ 151 __pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE); 152 } 153 154 static inline void 155 pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep) 156 { 157 extern pmdval_t user_pmd_table; 158 pmdval_t prot; 159 160 if (__LINUX_ARM_ARCH__ >= 6 && !IS_ENABLED(CONFIG_ARM_LPAE)) 161 prot = user_pmd_table; 162 else 163 prot = _PAGE_USER_TABLE; 164 165 __pmd_populate(pmdp, page_to_phys(ptep), prot); 166 } 167 #define pmd_pgtable(pmd) pmd_page(pmd) 168 169 #endif /* CONFIG_MMU */ 170 171 #endif 172