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 25 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr) 26 { 27 return (pmd_t *)get_zeroed_page(GFP_KERNEL); 28 } 29 30 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd) 31 { 32 BUG_ON((unsigned long)pmd & (PAGE_SIZE-1)); 33 free_page((unsigned long)pmd); 34 } 35 36 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd) 37 { 38 set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE)); 39 } 40 41 #else /* !CONFIG_ARM_LPAE */ 42 43 /* 44 * Since we have only two-level page tables, these are trivial 45 */ 46 #define pmd_alloc_one(mm,addr) ({ BUG(); ((pmd_t *)2); }) 47 #define pmd_free(mm, pmd) do { } while (0) 48 #define pud_populate(mm,pmd,pte) BUG() 49 50 #endif /* CONFIG_ARM_LPAE */ 51 52 extern pgd_t *pgd_alloc(struct mm_struct *mm); 53 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd); 54 55 static inline void clean_pte_table(pte_t *pte) 56 { 57 clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE); 58 } 59 60 /* 61 * Allocate one PTE table. 62 * 63 * This actually allocates two hardware PTE tables, but we wrap this up 64 * into one table thus: 65 * 66 * +------------+ 67 * | Linux pt 0 | 68 * +------------+ 69 * | Linux pt 1 | 70 * +------------+ 71 * | h/w pt 0 | 72 * +------------+ 73 * | h/w pt 1 | 74 * +------------+ 75 */ 76 77 #define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL 78 #define __HAVE_ARCH_PTE_ALLOC_ONE 79 #include <asm-generic/pgalloc.h> 80 81 static inline pte_t * 82 pte_alloc_one_kernel(struct mm_struct *mm) 83 { 84 pte_t *pte = __pte_alloc_one_kernel(mm); 85 86 if (pte) 87 clean_pte_table(pte); 88 89 return pte; 90 } 91 92 #ifdef CONFIG_HIGHPTE 93 #define PGTABLE_HIGHMEM __GFP_HIGHMEM 94 #else 95 #define PGTABLE_HIGHMEM 0 96 #endif 97 98 static inline pgtable_t 99 pte_alloc_one(struct mm_struct *mm) 100 { 101 struct page *pte; 102 103 pte = __pte_alloc_one(mm, GFP_PGTABLE_USER | PGTABLE_HIGHMEM); 104 if (!pte) 105 return NULL; 106 if (!PageHighMem(pte)) 107 clean_pte_table(page_address(pte)); 108 return pte; 109 } 110 111 static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte, 112 pmdval_t prot) 113 { 114 pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot; 115 pmdp[0] = __pmd(pmdval); 116 #ifndef CONFIG_ARM_LPAE 117 pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t)); 118 #endif 119 flush_pmd_entry(pmdp); 120 } 121 122 /* 123 * Populate the pmdp entry with a pointer to the pte. This pmd is part 124 * of the mm address space. 125 * 126 * Ensure that we always set both PMD entries. 127 */ 128 static inline void 129 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep) 130 { 131 /* 132 * The pmd must be loaded with the physical address of the PTE table 133 */ 134 __pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE); 135 } 136 137 static inline void 138 pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep) 139 { 140 extern pmdval_t user_pmd_table; 141 pmdval_t prot; 142 143 if (__LINUX_ARM_ARCH__ >= 6 && !IS_ENABLED(CONFIG_ARM_LPAE)) 144 prot = user_pmd_table; 145 else 146 prot = _PAGE_USER_TABLE; 147 148 __pmd_populate(pmdp, page_to_phys(ptep), prot); 149 } 150 #define pmd_pgtable(pmd) pmd_page(pmd) 151 152 #endif /* CONFIG_MMU */ 153 154 #endif 155