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