1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * arch/arm/include/asm/pgtable-3level.h 4 * 5 * Copyright (C) 2011 ARM Ltd. 6 * Author: Catalin Marinas <catalin.marinas@arm.com> 7 */ 8 #ifndef _ASM_PGTABLE_3LEVEL_H 9 #define _ASM_PGTABLE_3LEVEL_H 10 11 /* 12 * With LPAE, there are 3 levels of page tables. Each level has 512 entries of 13 * 8 bytes each, occupying a 4K page. The first level table covers a range of 14 * 512GB, each entry representing 1GB. Since we are limited to 4GB input 15 * address range, only 4 entries in the PGD are used. 16 * 17 * There are enough spare bits in a page table entry for the kernel specific 18 * state. 19 */ 20 #define PTRS_PER_PTE 512 21 #define PTRS_PER_PMD 512 22 #define PTRS_PER_PGD 4 23 24 #define PTE_HWTABLE_PTRS (0) 25 #define PTE_HWTABLE_OFF (0) 26 #define PTE_HWTABLE_SIZE (PTRS_PER_PTE * sizeof(u64)) 27 28 #define MAX_POSSIBLE_PHYSMEM_BITS 40 29 30 /* 31 * PGDIR_SHIFT determines the size a top-level page table entry can map. 32 */ 33 #define PGDIR_SHIFT 30 34 35 /* 36 * PMD_SHIFT determines the size a middle-level page table entry can map. 37 */ 38 #define PMD_SHIFT 21 39 40 #define PMD_SIZE (1UL << PMD_SHIFT) 41 #define PMD_MASK (~((1 << PMD_SHIFT) - 1)) 42 #define PGDIR_SIZE (1UL << PGDIR_SHIFT) 43 #define PGDIR_MASK (~((1 << PGDIR_SHIFT) - 1)) 44 45 /* 46 * section address mask and size definitions. 47 */ 48 #define SECTION_SHIFT 21 49 #define SECTION_SIZE (1UL << SECTION_SHIFT) 50 #define SECTION_MASK (~((1 << SECTION_SHIFT) - 1)) 51 52 #define USER_PTRS_PER_PGD (PAGE_OFFSET / PGDIR_SIZE) 53 54 /* 55 * Hugetlb definitions. 56 */ 57 #define HPAGE_SHIFT PMD_SHIFT 58 #define HPAGE_SIZE (_AC(1, UL) << HPAGE_SHIFT) 59 #define HPAGE_MASK (~(HPAGE_SIZE - 1)) 60 #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT) 61 62 /* 63 * "Linux" PTE definitions for LPAE. 64 * 65 * These bits overlap with the hardware bits but the naming is preserved for 66 * consistency with the classic page table format. 67 */ 68 #define L_PTE_VALID (_AT(pteval_t, 1) << 0) /* Valid */ 69 #define L_PTE_PRESENT (_AT(pteval_t, 3) << 0) /* Present */ 70 #define L_PTE_USER (_AT(pteval_t, 1) << 6) /* AP[1] */ 71 #define L_PTE_SHARED (_AT(pteval_t, 3) << 8) /* SH[1:0], inner shareable */ 72 #define L_PTE_YOUNG (_AT(pteval_t, 1) << 10) /* AF */ 73 #define L_PTE_XN (_AT(pteval_t, 1) << 54) /* XN */ 74 #define L_PTE_DIRTY (_AT(pteval_t, 1) << 55) 75 #define L_PTE_SPECIAL (_AT(pteval_t, 1) << 56) 76 #define L_PTE_NONE (_AT(pteval_t, 1) << 57) /* PROT_NONE */ 77 #define L_PTE_RDONLY (_AT(pteval_t, 1) << 58) /* READ ONLY */ 78 79 /* We borrow bit 7 to store the exclusive marker in swap PTEs. */ 80 #define L_PTE_SWP_EXCLUSIVE (_AT(pteval_t, 1) << 7) 81 82 #define L_PMD_SECT_VALID (_AT(pmdval_t, 1) << 0) 83 #define L_PMD_SECT_DIRTY (_AT(pmdval_t, 1) << 55) 84 #define L_PMD_SECT_NONE (_AT(pmdval_t, 1) << 57) 85 #define L_PMD_SECT_RDONLY (_AT(pteval_t, 1) << 58) 86 87 /* 88 * To be used in assembly code with the upper page attributes. 89 */ 90 #define L_PTE_XN_HIGH (1 << (54 - 32)) 91 #define L_PTE_DIRTY_HIGH (1 << (55 - 32)) 92 93 /* 94 * AttrIndx[2:0] encoding (mapping attributes defined in the MAIR* registers). 95 */ 96 #define L_PTE_MT_UNCACHED (_AT(pteval_t, 0) << 2) /* strongly ordered */ 97 #define L_PTE_MT_BUFFERABLE (_AT(pteval_t, 1) << 2) /* normal non-cacheable */ 98 #define L_PTE_MT_WRITETHROUGH (_AT(pteval_t, 2) << 2) /* normal inner write-through */ 99 #define L_PTE_MT_WRITEBACK (_AT(pteval_t, 3) << 2) /* normal inner write-back */ 100 #define L_PTE_MT_WRITEALLOC (_AT(pteval_t, 7) << 2) /* normal inner write-alloc */ 101 #define L_PTE_MT_DEV_SHARED (_AT(pteval_t, 4) << 2) /* device */ 102 #define L_PTE_MT_DEV_NONSHARED (_AT(pteval_t, 4) << 2) /* device */ 103 #define L_PTE_MT_DEV_WC (_AT(pteval_t, 1) << 2) /* normal non-cacheable */ 104 #define L_PTE_MT_DEV_CACHED (_AT(pteval_t, 3) << 2) /* normal inner write-back */ 105 #define L_PTE_MT_MASK (_AT(pteval_t, 7) << 2) 106 107 /* 108 * Software PGD flags. 109 */ 110 #define L_PGD_SWAPPER (_AT(pgdval_t, 1) << 55) /* swapper_pg_dir entry */ 111 112 #ifndef __ASSEMBLY__ 113 114 #define pud_none(pud) (!pud_val(pud)) 115 #define pud_bad(pud) (!(pud_val(pud) & PUD_TABLE_BIT)) 116 #define pud_present(pud) (pud_val(pud)) 117 #define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ 118 PMD_TYPE_TABLE) 119 #define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ 120 PMD_TYPE_SECT) 121 #define pmd_leaf(pmd) pmd_sect(pmd) 122 123 #define pud_clear(pudp) \ 124 do { \ 125 *pudp = __pud(0); \ 126 clean_pmd_entry(pudp); \ 127 } while (0) 128 129 #define set_pud(pudp, pud) \ 130 do { \ 131 *pudp = pud; \ 132 flush_pmd_entry(pudp); \ 133 } while (0) 134 135 static inline pmd_t *pud_pgtable(pud_t pud) 136 { 137 return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK); 138 } 139 140 #define pmd_bad(pmd) (!(pmd_val(pmd) & PMD_TABLE_BIT)) 141 142 #define copy_pmd(pmdpd,pmdps) \ 143 do { \ 144 *pmdpd = *pmdps; \ 145 flush_pmd_entry(pmdpd); \ 146 } while (0) 147 148 #define pmd_clear(pmdp) \ 149 do { \ 150 *pmdp = __pmd(0); \ 151 clean_pmd_entry(pmdp); \ 152 } while (0) 153 154 /* 155 * For 3 levels of paging the PTE_EXT_NG bit will be set for user address ptes 156 * that are written to a page table but not for ptes created with mk_pte. 157 * 158 * In hugetlb_no_page, a new huge pte (new_pte) is generated and passed to 159 * hugetlb_cow, where it is compared with an entry in a page table. 160 * This comparison test fails erroneously leading ultimately to a memory leak. 161 * 162 * To correct this behaviour, we mask off PTE_EXT_NG for any pte that is 163 * present before running the comparison. 164 */ 165 #define __HAVE_ARCH_PTE_SAME 166 #define pte_same(pte_a,pte_b) ((pte_present(pte_a) ? pte_val(pte_a) & ~PTE_EXT_NG \ 167 : pte_val(pte_a)) \ 168 == (pte_present(pte_b) ? pte_val(pte_b) & ~PTE_EXT_NG \ 169 : pte_val(pte_b))) 170 171 #define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,__pte(pte_val(pte)|(ext))) 172 173 #define pte_huge(pte) (pte_val(pte) && !(pte_val(pte) & PTE_TABLE_BIT)) 174 #define pte_mkhuge(pte) (__pte(pte_val(pte) & ~PTE_TABLE_BIT)) 175 176 #define pmd_isset(pmd, val) ((u32)(val) == (val) ? pmd_val(pmd) & (val) \ 177 : !!(pmd_val(pmd) & (val))) 178 #define pmd_isclear(pmd, val) (!(pmd_val(pmd) & (val))) 179 180 #define pmd_present(pmd) (pmd_isset((pmd), L_PMD_SECT_VALID)) 181 #define pmd_young(pmd) (pmd_isset((pmd), PMD_SECT_AF)) 182 #define pte_special(pte) (pte_isset((pte), L_PTE_SPECIAL)) 183 static inline pte_t pte_mkspecial(pte_t pte) 184 { 185 pte_val(pte) |= L_PTE_SPECIAL; 186 return pte; 187 } 188 189 #define pmd_write(pmd) (pmd_isclear((pmd), L_PMD_SECT_RDONLY)) 190 #define pmd_dirty(pmd) (pmd_isset((pmd), L_PMD_SECT_DIRTY)) 191 192 #define pmd_hugewillfault(pmd) (!pmd_young(pmd) || !pmd_write(pmd)) 193 194 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 195 #define pmd_trans_huge(pmd) (pmd_val(pmd) && !pmd_table(pmd)) 196 #endif 197 198 #define PMD_BIT_FUNC(fn,op) \ 199 static inline pmd_t pmd_##fn(pmd_t pmd) { pmd_val(pmd) op; return pmd; } 200 201 PMD_BIT_FUNC(wrprotect, |= L_PMD_SECT_RDONLY); 202 PMD_BIT_FUNC(mkold, &= ~PMD_SECT_AF); 203 PMD_BIT_FUNC(mkwrite_novma, &= ~L_PMD_SECT_RDONLY); 204 PMD_BIT_FUNC(mkdirty, |= L_PMD_SECT_DIRTY); 205 PMD_BIT_FUNC(mkclean, &= ~L_PMD_SECT_DIRTY); 206 PMD_BIT_FUNC(mkyoung, |= PMD_SECT_AF); 207 208 #define pmd_mkhuge(pmd) (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT)) 209 210 #define pmd_pfn(pmd) (((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT) 211 #define pfn_pmd(pfn,prot) (__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))) 212 #define mk_pmd(page,prot) pfn_pmd(page_to_pfn(page),prot) 213 214 /* No hardware dirty/accessed bits -- generic_pmdp_establish() fits */ 215 #define pmdp_establish generic_pmdp_establish 216 217 /* represent a notpresent pmd by faulting entry, this is used by pmdp_invalidate */ 218 static inline pmd_t pmd_mkinvalid(pmd_t pmd) 219 { 220 return __pmd(pmd_val(pmd) & ~L_PMD_SECT_VALID); 221 } 222 223 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) 224 { 225 const pmdval_t mask = PMD_SECT_USER | PMD_SECT_XN | L_PMD_SECT_RDONLY | 226 L_PMD_SECT_VALID | L_PMD_SECT_NONE; 227 pmd_val(pmd) = (pmd_val(pmd) & ~mask) | (pgprot_val(newprot) & mask); 228 return pmd; 229 } 230 231 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, 232 pmd_t *pmdp, pmd_t pmd) 233 { 234 BUG_ON(addr >= TASK_SIZE); 235 236 /* create a faulting entry if PROT_NONE protected */ 237 if (pmd_val(pmd) & L_PMD_SECT_NONE) 238 pmd_val(pmd) &= ~L_PMD_SECT_VALID; 239 240 if (pmd_write(pmd) && pmd_dirty(pmd)) 241 pmd_val(pmd) &= ~PMD_SECT_AP2; 242 else 243 pmd_val(pmd) |= PMD_SECT_AP2; 244 245 *pmdp = __pmd(pmd_val(pmd) | PMD_SECT_nG); 246 flush_pmd_entry(pmdp); 247 } 248 249 #endif /* __ASSEMBLY__ */ 250 251 #endif /* _ASM_PGTABLE_3LEVEL_H */ 252