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 static inline void clean_pte_table(pte_t *pte) 58 { 59 clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE); 60 } 61 62 /* 63 * Allocate one PTE table. 64 * 65 * This actually allocates two hardware PTE tables, but we wrap this up 66 * into one table thus: 67 * 68 * +------------+ 69 * | Linux pt 0 | 70 * +------------+ 71 * | Linux pt 1 | 72 * +------------+ 73 * | h/w pt 0 | 74 * +------------+ 75 * | h/w pt 1 | 76 * +------------+ 77 */ 78 79 #define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL 80 #define __HAVE_ARCH_PTE_ALLOC_ONE 81 #include <asm-generic/pgalloc.h> 82 83 static inline pte_t * 84 pte_alloc_one_kernel(struct mm_struct *mm) 85 { 86 pte_t *pte = __pte_alloc_one_kernel(mm); 87 88 if (pte) 89 clean_pte_table(pte); 90 91 return pte; 92 } 93 94 #ifdef CONFIG_HIGHPTE 95 #define PGTABLE_HIGHMEM __GFP_HIGHMEM 96 #else 97 #define PGTABLE_HIGHMEM 0 98 #endif 99 100 static inline pgtable_t 101 pte_alloc_one(struct mm_struct *mm) 102 { 103 struct page *pte; 104 105 pte = __pte_alloc_one(mm, GFP_PGTABLE_USER | PGTABLE_HIGHMEM); 106 if (!pte) 107 return NULL; 108 if (!PageHighMem(pte)) 109 clean_pte_table(page_address(pte)); 110 return pte; 111 } 112 113 static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte, 114 pmdval_t prot) 115 { 116 pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot; 117 pmdp[0] = __pmd(pmdval); 118 #ifndef CONFIG_ARM_LPAE 119 pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t)); 120 #endif 121 flush_pmd_entry(pmdp); 122 } 123 124 /* 125 * Populate the pmdp entry with a pointer to the pte. This pmd is part 126 * of the mm address space. 127 * 128 * Ensure that we always set both PMD entries. 129 */ 130 static inline void 131 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep) 132 { 133 /* 134 * The pmd must be loaded with the physical address of the PTE table 135 */ 136 __pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE); 137 } 138 139 static inline void 140 pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep) 141 { 142 extern pmdval_t user_pmd_table; 143 pmdval_t prot; 144 145 if (__LINUX_ARM_ARCH__ >= 6 && !IS_ENABLED(CONFIG_ARM_LPAE)) 146 prot = user_pmd_table; 147 else 148 prot = _PAGE_USER_TABLE; 149 150 __pmd_populate(pmdp, page_to_phys(ptep), prot); 151 } 152 #define pmd_pgtable(pmd) pmd_page(pmd) 153 154 #endif /* CONFIG_MMU */ 155 156 #endif 157