1 #ifndef _ASMARM64_PGTABLE_H_ 2 #define _ASMARM64_PGTABLE_H_ 3 /* 4 * Adapted from arch/arm64/include/asm/pgtable.h 5 * include/asm-generic/pgtable-nopmd.h 6 * include/linux/mm.h 7 * 8 * Note: some Linux function APIs have been modified. Nothing crazy, 9 * but if a function took, for example, an mm_struct, then 10 * that was either removed or replaced. 11 * 12 * Copyright (C) 2017, Red Hat Inc, Andrew Jones <drjones@redhat.com> 13 * 14 * This work is licensed under the terms of the GNU GPL, version 2. 15 */ 16 #include <alloc.h> 17 #include <alloc_page.h> 18 #include <asm/setup.h> 19 #include <asm/page.h> 20 #include <asm/pgtable-hwdef.h> 21 22 #include <linux/compiler.h> 23 24 /* 25 * We can convert va <=> pa page table addresses with simple casts 26 * because we always allocate their pages with alloc_page(), and 27 * alloc_page() always returns identity mapped pages. 28 */ 29 #define pgtable_va(x) ((void *)(unsigned long)(x)) 30 #define pgtable_pa(x) ((unsigned long)(x)) 31 32 #define pgd_none(pgd) (!pgd_val(pgd)) 33 #define pud_none(pud) (!pud_val(pud)) 34 #define pmd_none(pmd) (!pmd_val(pmd)) 35 #define pte_none(pte) (!pte_val(pte)) 36 37 #define pgd_valid(pgd) (pgd_val(pgd) & PGD_VALID) 38 #define pud_valid(pud) (pud_val(pud) & PUD_VALID) 39 #define pmd_valid(pmd) (pmd_val(pmd) & PMD_SECT_VALID) 40 #define pte_valid(pte) (pte_val(pte) & PTE_VALID) 41 42 #define pmd_huge(pmd) \ 43 ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_SECT) 44 45 #define pgd_index(addr) \ 46 (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)) 47 #define pgd_offset(pgtable, addr) ((pgtable) + pgd_index(addr)) 48 49 #define pgd_free(pgd) free(pgd) 50 static inline pgd_t *pgd_alloc(void) 51 { 52 pgd_t *pgd = memalign(PAGE_SIZE, PTRS_PER_PGD * sizeof(pgd_t)); 53 memset(pgd, 0, PTRS_PER_PGD * sizeof(pgd_t)); 54 return pgd; 55 } 56 57 static inline pud_t *pgd_page_vaddr(pgd_t pgd) 58 { 59 return pgtable_va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK); 60 } 61 62 static inline pmd_t *pud_page_vaddr(pud_t pud) 63 { 64 return pgtable_va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK); 65 } 66 67 static inline pte_t *pmd_page_vaddr(pmd_t pmd) 68 { 69 return pgtable_va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK); 70 } 71 72 #if PGTABLE_LEVELS > 2 73 #define pmd_index(addr) \ 74 (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)) 75 #define pmd_offset(pud, addr) \ 76 (pud_page_vaddr(*(pud)) + pmd_index(addr)) 77 #define pmd_free(pmd) free_page(pmd) 78 static inline pmd_t *pmd_alloc_one(void) 79 { 80 assert(PTRS_PER_PMD * sizeof(pmd_t) == PAGE_SIZE); 81 pmd_t *pmd = alloc_page(); 82 return pmd; 83 } 84 static inline pmd_t *pmd_alloc(pud_t *pud, unsigned long addr) 85 { 86 if (pud_none(*pud)) { 87 pud_t entry; 88 pud_val(entry) = pgtable_pa(pmd_alloc_one()) | PMD_TYPE_TABLE; 89 WRITE_ONCE(*pud, entry); 90 } 91 return pmd_offset(pud, addr); 92 } 93 #else 94 #define pmd_offset(pud, addr) ((pmd_t *)pud) 95 #define pmd_free(pmd) 96 #define pmd_alloc(pud, addr) pmd_offset(pud, addr) 97 #endif 98 99 #if PGTABLE_LEVELS > 3 100 #define pud_index(addr) \ 101 (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)) 102 #define pud_offset(pgd, addr) \ 103 (pgd_page_vaddr(*(pgd)) + pud_index(addr)) 104 #define pud_free(pud) free_page(pud) 105 static inline pud_t *pud_alloc_one(void) 106 { 107 assert(PTRS_PER_PUD * sizeof(pud_t) == PAGE_SIZE); 108 pud_t *pud = alloc_page(); 109 return pud; 110 } 111 static inline pud_t *pud_alloc(pgd_t *pgd, unsigned long addr) 112 { 113 if (pgd_none(*pgd)) { 114 pgd_t entry; 115 pgd_val(entry) = pgtable_pa(pud_alloc_one()) | PMD_TYPE_TABLE; 116 WRITE_ONCE(*pgd, entry); 117 } 118 return pud_offset(pgd, addr); 119 } 120 #else 121 #define pud_offset(pgd, addr) ((pud_t *)pgd) 122 #define pud_free(pud) 123 #define pud_alloc(pgd, addr) pud_offset(pgd, addr) 124 #endif 125 126 #define pte_index(addr) \ 127 (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 128 #define pte_offset(pmd, addr) \ 129 (pmd_page_vaddr(*(pmd)) + pte_index(addr)) 130 131 #define pte_free(pte) free_page(pte) 132 static inline pte_t *pte_alloc_one(void) 133 { 134 assert(PTRS_PER_PTE * sizeof(pte_t) == PAGE_SIZE); 135 pte_t *pte = alloc_page(); 136 return pte; 137 } 138 static inline pte_t *pte_alloc(pmd_t *pmd, unsigned long addr) 139 { 140 if (pmd_none(*pmd)) { 141 pmd_t entry; 142 pmd_val(entry) = pgtable_pa(pte_alloc_one()) | PMD_TYPE_TABLE; 143 WRITE_ONCE(*pmd, entry); 144 } 145 return pte_offset(pmd, addr); 146 } 147 148 #endif /* _ASMARM64_PGTABLE_H_ */ 149