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 #ifdef CONFIG_MMU 19 20 #define _PAGE_USER_TABLE (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER)) 21 #define _PAGE_KERNEL_TABLE (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL)) 22 23 #ifdef CONFIG_ARM_LPAE 24 #define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t)) 25 26 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd) 27 { 28 set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE)); 29 } 30 31 #else /* !CONFIG_ARM_LPAE */ 32 #define PGD_SIZE (PAGE_SIZE << 2) 33 34 /* 35 * Since we have only two-level page tables, these are trivial 36 */ 37 #define pmd_alloc_one(mm,addr) ({ BUG(); ((pmd_t *)2); }) 38 #define pmd_free(mm, pmd) do { } while (0) 39 #ifdef CONFIG_KASAN 40 /* The KASan core unconditionally calls pud_populate() on all architectures */ 41 #define pud_populate(mm,pmd,pte) do { } while (0) 42 #else 43 #define pud_populate(mm,pmd,pte) BUG() 44 #endif 45 #endif /* CONFIG_ARM_LPAE */ 46 47 extern pgd_t *pgd_alloc(struct mm_struct *mm); 48 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd); 49 50 static inline void clean_pte_table(pte_t *pte) 51 { 52 clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE); 53 } 54 55 /* 56 * Allocate one PTE table. 57 * 58 * This actually allocates two hardware PTE tables, but we wrap this up 59 * into one table thus: 60 * 61 * +------------+ 62 * | Linux pt 0 | 63 * +------------+ 64 * | Linux pt 1 | 65 * +------------+ 66 * | h/w pt 0 | 67 * +------------+ 68 * | h/w pt 1 | 69 * +------------+ 70 */ 71 72 #define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL 73 #define __HAVE_ARCH_PTE_ALLOC_ONE 74 #define __HAVE_ARCH_PGD_FREE 75 #include <asm-generic/pgalloc.h> 76 77 static inline pte_t * 78 pte_alloc_one_kernel(struct mm_struct *mm) 79 { 80 pte_t *pte = __pte_alloc_one_kernel(mm); 81 82 if (pte) 83 clean_pte_table(pte); 84 85 return pte; 86 } 87 88 #ifdef CONFIG_HIGHPTE 89 #define PGTABLE_HIGHMEM __GFP_HIGHMEM 90 #else 91 #define PGTABLE_HIGHMEM 0 92 #endif 93 94 static inline pgtable_t 95 pte_alloc_one(struct mm_struct *mm) 96 { 97 struct page *pte; 98 99 pte = __pte_alloc_one(mm, GFP_PGTABLE_USER | PGTABLE_HIGHMEM); 100 if (!pte) 101 return NULL; 102 if (!PageHighMem(pte)) 103 clean_pte_table(page_address(pte)); 104 return pte; 105 } 106 107 static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte, 108 pmdval_t prot) 109 { 110 pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot; 111 pmdp[0] = __pmd(pmdval); 112 #ifndef CONFIG_ARM_LPAE 113 pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t)); 114 #endif 115 flush_pmd_entry(pmdp); 116 } 117 118 /* 119 * Populate the pmdp entry with a pointer to the pte. This pmd is part 120 * of the mm address space. 121 * 122 * Ensure that we always set both PMD entries. 123 */ 124 static inline void 125 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep) 126 { 127 /* 128 * The pmd must be loaded with the physical address of the PTE table 129 */ 130 __pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE); 131 } 132 133 static inline void 134 pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep) 135 { 136 extern pmdval_t user_pmd_table; 137 pmdval_t prot; 138 139 if (__LINUX_ARM_ARCH__ >= 6 && !IS_ENABLED(CONFIG_ARM_LPAE)) 140 prot = user_pmd_table; 141 else 142 prot = _PAGE_USER_TABLE; 143 144 __pmd_populate(pmdp, page_to_phys(ptep), prot); 145 } 146 147 #endif /* CONFIG_MMU */ 148 149 #endif 150