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 17 /* 18 * We can convert va <=> pa page table addresses with simple casts 19 * because we always allocate their pages with alloc_page(), and 20 * alloc_page() always returns identity mapped pages. 21 */ 22 #define pgtable_va(x) ((void *)(unsigned long)(x)) 23 #define pgtable_pa(x) ((unsigned long)(x)) 24 25 #define pgd_none(pgd) (!pgd_val(pgd)) 26 #define pmd_none(pmd) (!pmd_val(pmd)) 27 #define pte_none(pte) (!pte_val(pte)) 28 29 #define pgd_index(addr) \ 30 (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)) 31 #define pgd_offset(pgtable, addr) ((pgtable) + pgd_index(addr)) 32 33 #define pgd_free(pgd) free(pgd) 34 static inline pgd_t *pgd_alloc(void) 35 { 36 pgd_t *pgd = memalign(L1_CACHE_BYTES, PTRS_PER_PGD * sizeof(pgd_t)); 37 memset(pgd, 0, PTRS_PER_PGD * sizeof(pgd_t)); 38 return pgd; 39 } 40 41 static inline pmd_t *pgd_page_vaddr(pgd_t pgd) 42 { 43 return pgtable_va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK); 44 } 45 46 #define pmd_index(addr) \ 47 (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)) 48 #define pmd_offset(pgd, addr) \ 49 (pgd_page_vaddr(*(pgd)) + pmd_index(addr)) 50 51 #define pmd_free(pmd) free_page(pmd) 52 static inline pmd_t *pmd_alloc_one(void) 53 { 54 assert(PTRS_PER_PMD * sizeof(pmd_t) == PAGE_SIZE); 55 pmd_t *pmd = alloc_page(); 56 return pmd; 57 } 58 static inline pmd_t *pmd_alloc(pgd_t *pgd, unsigned long addr) 59 { 60 if (pgd_none(*pgd)) { 61 pmd_t *pmd = pmd_alloc_one(); 62 pgd_val(*pgd) = pgtable_pa(pmd) | PMD_TYPE_TABLE; 63 } 64 return pmd_offset(pgd, addr); 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 #define pte_index(addr) \ 73 (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 74 #define pte_offset(pmd, addr) \ 75 (pmd_page_vaddr(*(pmd)) + pte_index(addr)) 76 77 #define pte_free(pte) free_page(pte) 78 static inline pte_t *pte_alloc_one(void) 79 { 80 assert(PTRS_PER_PTE * sizeof(pte_t) == PAGE_SIZE); 81 pte_t *pte = alloc_page(); 82 return pte; 83 } 84 static inline pte_t *pte_alloc(pmd_t *pmd, unsigned long addr) 85 { 86 if (pmd_none(*pmd)) { 87 pte_t *pte = pte_alloc_one(); 88 pmd_val(*pmd) = pgtable_pa(pte) | PMD_TYPE_TABLE; 89 } 90 return pte_offset(pmd, addr); 91 } 92 93 #endif /* _ASMARM_PGTABLE_H_ */ 94