projects/linux·blob master · refs

250 lines · 7.9 KiB

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 <[email protected]>
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
135static 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))
183static 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) \
199static inline pmd_t pmd_##fn(pmd_t pmd) { pmd_val(pmd) op; return pmd; }
200
201PMD_BIT_FUNC(wrprotect, |= L_PMD_SECT_RDONLY);
202PMD_BIT_FUNC(mkold, &= ~PMD_SECT_AF);
203PMD_BIT_FUNC(mkwrite_novma, &= ~L_PMD_SECT_RDONLY);
204PMD_BIT_FUNC(mkdirty, |= L_PMD_SECT_DIRTY);
205PMD_BIT_FUNC(mkclean, &= ~L_PMD_SECT_DIRTY);
206PMD_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
213/* No hardware dirty/accessed bits -- generic_pmdp_establish() fits */
214#define pmdp_establish generic_pmdp_establish
215
216/* represent a notpresent pmd by faulting entry, this is used by pmdp_invalidate */
217static inline pmd_t pmd_mkinvalid(pmd_t pmd)
218{
219 return __pmd(pmd_val(pmd) & ~L_PMD_SECT_VALID);
220}
221
222static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
223{
224 const pmdval_t mask = PMD_SECT_USER | PMD_SECT_XN | L_PMD_SECT_RDONLY |
225 L_PMD_SECT_VALID | L_PMD_SECT_NONE;
226 pmd_val(pmd) = (pmd_val(pmd) & ~mask) | (pgprot_val(newprot) & mask);
227 return pmd;
228}
229
230static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
231 pmd_t *pmdp, pmd_t pmd)
232{
233 BUG_ON(addr >= TASK_SIZE);
234
235 /* create a faulting entry if PROT_NONE protected */
236 if (pmd_val(pmd) & L_PMD_SECT_NONE)
237 pmd_val(pmd) &= ~L_PMD_SECT_VALID;
238
239 if (pmd_write(pmd) && pmd_dirty(pmd))
240 pmd_val(pmd) &= ~PMD_SECT_AP2;
241 else
242 pmd_val(pmd) |= PMD_SECT_AP2;
243
244 *pmdp = __pmd(pmd_val(pmd) | PMD_SECT_nG);
245 flush_pmd_entry(pmdp);
246}
247
248#endif /* __ASSEMBLY__ */
249
250#endif /* _ASM_PGTABLE_3LEVEL_H */