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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
57static inline void clean_pte_table(pte_t *pte)
58{
59 clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
60}
61
62/*
63 * Allocate one PTE table.
64 *
65 * This actually allocates two hardware PTE tables, but we wrap this up
66 * into one table thus:
67 *
68 * +------------+
69 * | Linux pt 0 |
70 * +------------+
71 * | Linux pt 1 |
72 * +------------+
73 * | h/w pt 0 |
74 * +------------+
75 * | h/w pt 1 |
76 * +------------+
77 */
78
79#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
80#define __HAVE_ARCH_PTE_ALLOC_ONE
81#include <asm-generic/pgalloc.h>
82
83static inline pte_t *
84pte_alloc_one_kernel(struct mm_struct *mm)
85{
86 pte_t *pte = __pte_alloc_one_kernel(mm);
87
88 if (pte)
89 clean_pte_table(pte);
90
91 return pte;
92}
93
94#ifdef CONFIG_HIGHPTE
95#define PGTABLE_HIGHMEM __GFP_HIGHMEM
96#else
97#define PGTABLE_HIGHMEM 0
98#endif
99
100static inline pgtable_t
101pte_alloc_one(struct mm_struct *mm)
102{
103 struct page *pte;
104
105 pte = __pte_alloc_one(mm, GFP_PGTABLE_USER | PGTABLE_HIGHMEM);
106 if (!pte)
107 return NULL;
108 if (!PageHighMem(pte))
109 clean_pte_table(page_address(pte));
110 return pte;
111}
112
113static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
114 pmdval_t prot)
115{
116 pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot;
117 pmdp[0] = __pmd(pmdval);
118#ifndef CONFIG_ARM_LPAE
119 pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
120#endif
121 flush_pmd_entry(pmdp);
122}
123
124/*
125 * Populate the pmdp entry with a pointer to the pte. This pmd is part
126 * of the mm address space.
127 *
128 * Ensure that we always set both PMD entries.
129 */
130static inline void
131pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
132{
133 /*
134 * The pmd must be loaded with the physical address of the PTE table
135 */
136 __pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE);
137}
138
139static inline void
140pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
141{
142 extern pmdval_t user_pmd_table;
143 pmdval_t prot;
144
145 if (__LINUX_ARM_ARCH__ >= 6 && !IS_ENABLED(CONFIG_ARM_LPAE))
146 prot = user_pmd_table;
147 else
148 prot = _PAGE_USER_TABLE;
149
150 __pmd_populate(pmdp, page_to_phys(ptep), prot);
151}
152#define pmd_pgtable(pmd) pmd_page(pmd)
153
154#endif /* CONFIG_MMU */
155
156#endif