Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * arch/arm/include/asm/pgalloc.h
4 *
5 * Copyright (C) 2000-2001 Russell King
6 */
7#ifndef _ASMARM_PGALLOC_H
8#define _ASMARM_PGALLOC_H
9
10#include <linux/pagemap.h>
11
12#include <asm/domain.h>
13#include <asm/pgtable-hwdef.h>
14#include <asm/processor.h>
15#include <asm/cacheflush.h>
16#include <asm/tlbflush.h>
17
18#define check_pgt_cache() do { } while (0)
19
20#ifdef CONFIG_MMU
21
22#define _PAGE_USER_TABLE (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER))
23#define _PAGE_KERNEL_TABLE (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL))
24
25#ifdef CONFIG_ARM_LPAE
26
27static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
28{
29 return (pmd_t *)get_zeroed_page(GFP_KERNEL);
30}
31
32static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
33{
34 BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
35 free_page((unsigned long)pmd);
36}
37
38static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
39{
40 set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
41}
42
43#else /* !CONFIG_ARM_LPAE */
44
45/*
46 * Since we have only two-level page tables, these are trivial
47 */
48#define pmd_alloc_one(mm,addr) ({ BUG(); ((pmd_t *)2); })
49#define pmd_free(mm, pmd) do { } while (0)
50#define pud_populate(mm,pmd,pte) BUG()
51
52#endif /* CONFIG_ARM_LPAE */
53
54extern pgd_t *pgd_alloc(struct mm_struct *mm);
55extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
56
57#define PGALLOC_GFP (GFP_KERNEL | __GFP_ZERO)
58
59static inline void clean_pte_table(pte_t *pte)
60{
61 clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
62}
63
64/*
65 * Allocate one PTE table.
66 *
67 * This actually allocates two hardware PTE tables, but we wrap this up
68 * into one table thus:
69 *
70 * +------------+
71 * | Linux pt 0 |
72 * +------------+
73 * | Linux pt 1 |
74 * +------------+
75 * | h/w pt 0 |
76 * +------------+
77 * | h/w pt 1 |
78 * +------------+
79 */
80static inline pte_t *
81pte_alloc_one_kernel(struct mm_struct *mm)
82{
83 pte_t *pte;
84
85 pte = (pte_t *)__get_free_page(PGALLOC_GFP);
86 if (pte)
87 clean_pte_table(pte);
88
89 return pte;
90}
91
92static inline pgtable_t
93pte_alloc_one(struct mm_struct *mm)
94{
95 struct page *pte;
96
97#ifdef CONFIG_HIGHPTE
98 pte = alloc_pages(PGALLOC_GFP | __GFP_HIGHMEM, 0);
99#else
100 pte = alloc_pages(PGALLOC_GFP, 0);
101#endif
102 if (!pte)
103 return NULL;
104 if (!PageHighMem(pte))
105 clean_pte_table(page_address(pte));
106 if (!pgtable_page_ctor(pte)) {
107 __free_page(pte);
108 return NULL;
109 }
110 return pte;
111}
112
113/*
114 * Free one PTE table.
115 */
116static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
117{
118 if (pte)
119 free_page((unsigned long)pte);
120}
121
122static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
123{
124 pgtable_page_dtor(pte);
125 __free_page(pte);
126}
127
128static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
129 pmdval_t prot)
130{
131 pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot;
132 pmdp[0] = __pmd(pmdval);
133#ifndef CONFIG_ARM_LPAE
134 pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
135#endif
136 flush_pmd_entry(pmdp);
137}
138
139/*
140 * Populate the pmdp entry with a pointer to the pte. This pmd is part
141 * of the mm address space.
142 *
143 * Ensure that we always set both PMD entries.
144 */
145static inline void
146pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
147{
148 /*
149 * The pmd must be loaded with the physical address of the PTE table
150 */
151 __pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE);
152}
153
154static inline void
155pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
156{
157 extern pmdval_t user_pmd_table;
158 pmdval_t prot;
159
160 if (__LINUX_ARM_ARCH__ >= 6 && !IS_ENABLED(CONFIG_ARM_LPAE))
161 prot = user_pmd_table;
162 else
163 prot = _PAGE_USER_TABLE;
164
165 __pmd_populate(pmdp, page_to_phys(ptep), prot);
166}
167#define pmd_pgtable(pmd) pmd_page(pmd)
168
169#endif /* CONFIG_MMU */
170
171#endif