1 #ifndef _ASMARM_PGTABLE_H_ 2 #define _ASMARM_PGTABLE_H_ 3 /* 4 * Adapted from arch/arm/include/asm/pgtable.h 5 * arch/arm/include/asm/pgtable-3level.h 6 * arch/arm/include/asm/pgalloc.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_page.h> 17 18 /* 19 * We can convert va <=> pa page table addresses with simple casts 20 * because we always allocate their pages with alloc_page(), and 21 * alloc_page() always returns identity mapped pages. 22 */ 23 #include <linux/compiler.h> 24 25 #define pgtable_va(x) ((void *)(unsigned long)(x)) 26 #define pgtable_pa(x) ((unsigned long)(x)) 27 28 #define pgd_none(pgd) (!pgd_val(pgd)) 29 #define pmd_none(pmd) (!pmd_val(pmd)) 30 #define pte_none(pte) (!pte_val(pte)) 31 32 #define pgd_valid(pgd) (pgd_val(pgd) & PGD_VALID) 33 #define pmd_valid(pmd) (pmd_val(pmd) & PMD_SECT_VALID) 34 #define pte_valid(pte) (pte_val(pte) & L_PTE_VALID) 35 36 #define pmd_huge(pmd) \ 37 ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_SECT) 38 39 #define pgd_index(addr) \ 40 (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)) 41 #define pgd_offset(pgtable, addr) ((pgtable) + pgd_index(addr)) 42 43 #define pgd_free(pgd) free(pgd) 44 static inline pgd_t *pgd_alloc(void) 45 { 46 pgd_t *pgd = memalign(L1_CACHE_BYTES, PTRS_PER_PGD * sizeof(pgd_t)); 47 memset(pgd, 0, PTRS_PER_PGD * sizeof(pgd_t)); 48 return pgd; 49 } 50 51 static inline pmd_t *pgd_page_vaddr(pgd_t pgd) 52 { 53 return pgtable_va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK); 54 } 55 56 /* For compatibility with arm64 page tables */ 57 #define pud_valid(pud) pgd_valid(pud) 58 #define pud_offset(pgd, addr) ((pud_t *)pgd) 59 #define pud_free(pud) 60 #define pud_alloc(pgd, addr) pud_offset(pgd, addr) 61 62 #define pmd_index(addr) \ 63 (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)) 64 #define pmd_offset(pgd, addr) \ 65 (pgd_page_vaddr(*(pgd)) + pmd_index(addr)) 66 67 #define pmd_free(pmd) free_page(pmd) 68 static inline pmd_t *pmd_alloc_one(void) 69 { 70 assert(PTRS_PER_PMD * sizeof(pmd_t) == PAGE_SIZE); 71 pmd_t *pmd = alloc_page(); 72 return pmd; 73 } 74 static inline pmd_t *pmd_alloc(pgd_t *pgd, unsigned long addr) 75 { 76 if (pgd_none(*pgd)) { 77 pgd_t entry; 78 pgd_val(entry) = pgtable_pa(pmd_alloc_one()) | PMD_TYPE_TABLE; 79 WRITE_ONCE(*pgd, entry); 80 } 81 return pmd_offset(pgd, addr); 82 } 83 84 static inline pte_t *pmd_page_vaddr(pmd_t pmd) 85 { 86 return pgtable_va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK); 87 } 88 89 #define pte_index(addr) \ 90 (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 91 #define pte_offset(pmd, addr) \ 92 (pmd_page_vaddr(*(pmd)) + pte_index(addr)) 93 94 #define pte_free(pte) free_page(pte) 95 static inline pte_t *pte_alloc_one(void) 96 { 97 assert(PTRS_PER_PTE * sizeof(pte_t) == PAGE_SIZE); 98 pte_t *pte = alloc_page(); 99 return pte; 100 } 101 static inline pte_t *pte_alloc(pmd_t *pmd, unsigned long addr) 102 { 103 if (pmd_none(*pmd)) { 104 pmd_t entry; 105 pmd_val(entry) = pgtable_pa(pte_alloc_one()) | PMD_TYPE_TABLE; 106 WRITE_ONCE(*pmd, entry); 107 } 108 return pte_offset(pmd, addr); 109 } 110 111 #endif /* _ASMARM_PGTABLE_H_ */ 112