xref: /openbmc/linux/arch/arm/include/asm/pgalloc.h (revision be709d48)
1 /*
2  *  arch/arm/include/asm/pgalloc.h
3  *
4  *  Copyright (C) 2000-2001 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 #ifndef _ASMARM_PGALLOC_H
11 #define _ASMARM_PGALLOC_H
12 
13 #include <linux/pagemap.h>
14 
15 #include <asm/domain.h>
16 #include <asm/pgtable-hwdef.h>
17 #include <asm/processor.h>
18 #include <asm/cacheflush.h>
19 #include <asm/tlbflush.h>
20 
21 #define check_pgt_cache()		do { } while (0)
22 
23 #ifdef CONFIG_MMU
24 
25 #define _PAGE_USER_TABLE	(PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER))
26 #define _PAGE_KERNEL_TABLE	(PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL))
27 
28 #ifdef CONFIG_ARM_LPAE
29 
30 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
31 {
32 	return (pmd_t *)get_zeroed_page(GFP_KERNEL);
33 }
34 
35 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
36 {
37 	BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
38 	free_page((unsigned long)pmd);
39 }
40 
41 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
42 {
43 	set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
44 }
45 
46 #else	/* !CONFIG_ARM_LPAE */
47 
48 /*
49  * Since we have only two-level page tables, these are trivial
50  */
51 #define pmd_alloc_one(mm,addr)		({ BUG(); ((pmd_t *)2); })
52 #define pmd_free(mm, pmd)		do { } while (0)
53 #define pud_populate(mm,pmd,pte)	BUG()
54 
55 #endif	/* CONFIG_ARM_LPAE */
56 
57 extern pgd_t *pgd_alloc(struct mm_struct *mm);
58 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
59 
60 #define PGALLOC_GFP	(GFP_KERNEL | __GFP_ZERO)
61 
62 static inline void clean_pte_table(pte_t *pte)
63 {
64 	clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
65 }
66 
67 /*
68  * Allocate one PTE table.
69  *
70  * This actually allocates two hardware PTE tables, but we wrap this up
71  * into one table thus:
72  *
73  *  +------------+
74  *  | Linux pt 0 |
75  *  +------------+
76  *  | Linux pt 1 |
77  *  +------------+
78  *  |  h/w pt 0  |
79  *  +------------+
80  *  |  h/w pt 1  |
81  *  +------------+
82  */
83 static inline pte_t *
84 pte_alloc_one_kernel(struct mm_struct *mm)
85 {
86 	pte_t *pte;
87 
88 	pte = (pte_t *)__get_free_page(PGALLOC_GFP);
89 	if (pte)
90 		clean_pte_table(pte);
91 
92 	return pte;
93 }
94 
95 static inline pgtable_t
96 pte_alloc_one(struct mm_struct *mm)
97 {
98 	struct page *pte;
99 
100 #ifdef CONFIG_HIGHPTE
101 	pte = alloc_pages(PGALLOC_GFP | __GFP_HIGHMEM, 0);
102 #else
103 	pte = alloc_pages(PGALLOC_GFP, 0);
104 #endif
105 	if (!pte)
106 		return NULL;
107 	if (!PageHighMem(pte))
108 		clean_pte_table(page_address(pte));
109 	if (!pgtable_page_ctor(pte)) {
110 		__free_page(pte);
111 		return NULL;
112 	}
113 	return pte;
114 }
115 
116 /*
117  * Free one PTE table.
118  */
119 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
120 {
121 	if (pte)
122 		free_page((unsigned long)pte);
123 }
124 
125 static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
126 {
127 	pgtable_page_dtor(pte);
128 	__free_page(pte);
129 }
130 
131 static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
132 				  pmdval_t prot)
133 {
134 	pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot;
135 	pmdp[0] = __pmd(pmdval);
136 #ifndef CONFIG_ARM_LPAE
137 	pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
138 #endif
139 	flush_pmd_entry(pmdp);
140 }
141 
142 /*
143  * Populate the pmdp entry with a pointer to the pte.  This pmd is part
144  * of the mm address space.
145  *
146  * Ensure that we always set both PMD entries.
147  */
148 static inline void
149 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
150 {
151 	/*
152 	 * The pmd must be loaded with the physical address of the PTE table
153 	 */
154 	__pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE);
155 }
156 
157 static inline void
158 pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
159 {
160 	extern pmdval_t user_pmd_table;
161 	pmdval_t prot;
162 
163 	if (__LINUX_ARM_ARCH__ >= 6 && !IS_ENABLED(CONFIG_ARM_LPAE))
164 		prot = user_pmd_table;
165 	else
166 		prot = _PAGE_USER_TABLE;
167 
168 	__pmd_populate(pmdp, page_to_phys(ptep), prot);
169 }
170 #define pmd_pgtable(pmd) pmd_page(pmd)
171 
172 #endif /* CONFIG_MMU */
173 
174 #endif
175