summaryrefslogtreecommitdiff
path: root/include/asm-generic/pgalloc.h
blob: 02932efad3ab469ff700816c0fea40c17c4f11c1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_GENERIC_PGALLOC_H
#define __ASM_GENERIC_PGALLOC_H

#ifdef CONFIG_MMU

#define GFP_PGTABLE_KERNEL	(GFP_KERNEL | __GFP_ZERO)
#define GFP_PGTABLE_USER	(GFP_PGTABLE_KERNEL | __GFP_ACCOUNT)

/**
 * __pte_alloc_one_kernel - allocate a page for PTE-level kernel page table
 * @mm: the mm_struct of the current context
 *
 * This function is intended for architectures that need
 * anything beyond simple page allocation.
 *
 * Return: pointer to the allocated memory or %NULL on error
 */
static inline pte_t *__pte_alloc_one_kernel(struct mm_struct *mm)
{
	return (pte_t *)__get_free_page(GFP_PGTABLE_KERNEL);
}

#ifndef __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
/**
 * pte_alloc_one_kernel - allocate a page for PTE-level kernel page table
 * @mm: the mm_struct of the current context
 *
 * Return: pointer to the allocated memory or %NULL on error
 */
static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
{
	return __pte_alloc_one_kernel(mm);
}
#endif

/**
 * pte_free_kernel - free PTE-level kernel page table page
 * @mm: the mm_struct of the current context
 * @pte: pointer to the memory containing the page table
 */
static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
	free_page((unsigned long)pte);
}

/**
 * __pte_alloc_one - allocate a page for PTE-level user page table
 * @mm: the mm_struct of the current context
 * @gfp: GFP flags to use for the allocation
 *
 * Allocates a page and runs the pgtable_pte_page_ctor().
 *
 * This function is intended for architectures that need
 * anything beyond simple page allocation or must have custom GFP flags.
 *
 * Return: `struct page` initialized as page table or %NULL on error
 */
static inline pgtable_t __pte_alloc_one(struct mm_struct *mm, gfp_t gfp)
{
	struct page *pte;

	pte = alloc_page(gfp);
	if (!pte)
		return NULL;
	if (!pgtable_pte_page_ctor(pte)) {
		__free_page(pte);
		return NULL;
	}

	return pte;
}

#ifndef __HAVE_ARCH_PTE_ALLOC_ONE
/**
 * pte_alloc_one - allocate a page for PTE-level user page table
 * @mm: the mm_struct of the current context
 *
 * Allocates a page and runs the pgtable_pte_page_ctor().
 *
 * Return: `struct page` initialized as page table or %NULL on error
 */
static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
{
	return __pte_alloc_one(mm, GFP_PGTABLE_USER);
}
#endif

/*
 * Should really implement gc for free page table pages. This could be
 * done with a reference count in struct page.
 */

/**
 * pte_free - free PTE-level user page table page
 * @mm: the mm_struct of the current context
 * @pte_page: the `struct page` representing the page table
 */
static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
{
	pgtable_pte_page_dtor(pte_page);
	__free_page(pte_page);
}


#if CONFIG_PGTABLE_LEVELS > 2

#ifndef __HAVE_ARCH_PMD_ALLOC_ONE
/**
 * pmd_alloc_one - allocate a page for PMD-level page table
 * @mm: the mm_struct of the current context
 *
 * Allocates a page and runs the pgtable_pmd_page_ctor().
 * Allocations use %GFP_PGTABLE_USER in user context and
 * %GFP_PGTABLE_KERNEL in kernel context.
 *
 * Return: pointer to the allocated memory or %NULL on error
 */
static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
{
	struct page *page;
	gfp_t gfp = GFP_PGTABLE_USER;

	if (mm == &init_mm)
		gfp = GFP_PGTABLE_KERNEL;
	page = alloc_pages(gfp, 0);
	if (!page)
		return NULL;
	if (!pgtable_pmd_page_ctor(page)) {
		__free_pages(page, 0);
		return NULL;
	}
	return (pmd_t *)page_address(page);
}
#endif

#ifndef __HAVE_ARCH_PMD_FREE
static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
{
	BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
	pgtable_pmd_page_dtor(virt_to_page(pmd));
	free_page((unsigned long)pmd);
}
#endif

#endif /* CONFIG_PGTABLE_LEVELS > 2 */

#if CONFIG_PGTABLE_LEVELS > 3

#ifndef __HAVE_ARCH_PUD_ALLOC_ONE
/**
 * pud_alloc_one - allocate a page for PUD-level page table
 * @mm: the mm_struct of the current context
 *
 * Allocates a page using %GFP_PGTABLE_USER for user context and
 * %GFP_PGTABLE_KERNEL for kernel context.
 *
 * Return: pointer to the allocated memory or %NULL on error
 */
static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
{
	gfp_t gfp = GFP_PGTABLE_USER;

	if (mm == &init_mm)
		gfp = GFP_PGTABLE_KERNEL;
	return (pud_t *)get_zeroed_page(gfp);
}
#endif

static inline void pud_free(struct mm_struct *mm, pud_t *pud)
{
	BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
	free_page((unsigned long)pud);
}

#endif /* CONFIG_PGTABLE_LEVELS > 3 */

#ifndef __HAVE_ARCH_PGD_FREE
static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
	free_page((unsigned long)pgd);
}
#endif

#endif /* CONFIG_MMU */

#endif /* __ASM_GENERIC_PGALLOC_H */