aboutsummaryrefslogtreecommitdiff
path: root/include/linux/highmem.h
blob: 7ff5c55f9b554120379baadd28be15cebbfe839a (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
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
#ifndef _LINUX_HIGHMEM_H
#define _LINUX_HIGHMEM_H

#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/uaccess.h>

#include <asm/cacheflush.h>

#ifndef ARCH_HAS_FLUSH_ANON_PAGE
static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
{
}
#endif

#ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
static inline void flush_kernel_dcache_page(struct page *page)
{
}
#endif

#ifdef CONFIG_HIGHMEM

#include <asm/highmem.h>

/* declarations for linux/mm/highmem.c */
unsigned int nr_free_highpages(void);
extern unsigned long totalhigh_pages;

void kmap_flush_unused(void);

#else /* CONFIG_HIGHMEM */

static inline unsigned int nr_free_highpages(void) { return 0; }

#define totalhigh_pages 0

#ifndef ARCH_HAS_KMAP
static inline void *kmap(struct page *page)
{
	might_sleep();
	return page_address(page);
}

#define kunmap(page) do { (void) (page); } while (0)

#include <asm/kmap_types.h>

static inline void *kmap_atomic(struct page *page, enum km_type idx)
{
	pagefault_disable();
	return page_address(page);
}
#define kmap_atomic_prot(page, idx, prot)	kmap_atomic(page, idx)

#define kunmap_atomic(addr, idx)	do { pagefault_enable(); } while (0)
#define kmap_atomic_pfn(pfn, idx)	kmap_atomic(pfn_to_page(pfn), (idx))
#define kmap_atomic_to_page(ptr)	virt_to_page(ptr)

#define kmap_flush_unused()	do {} while(0)
#endif

#endif /* CONFIG_HIGHMEM */

/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
#ifndef clear_user_highpage
static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
{
	void *addr = kmap_atomic(page, KM_USER0);
	clear_user_page(addr, vaddr, page);
	kunmap_atomic(addr, KM_USER0);
}
#endif

#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
/**
 * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
 * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
 * @vma: The VMA the page is to be allocated for
 * @vaddr: The virtual address the page will be inserted into
 *
 * This function will allocate a page for a VMA but the caller is expected
 * to specify via movableflags whether the page will be movable in the
 * future or not
 *
 * An architecture may override this function by defining
 * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
 * implementation.
 */
static inline struct page *
__alloc_zeroed_user_highpage(gfp_t movableflags,
			struct vm_area_struct *vma,
			unsigned long vaddr)
{
	struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
			vma, vaddr);

	if (page)
		clear_user_highpage(page, vaddr);

	return page;
}
#endif

/**
 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
 * @vma: The VMA the page is to be allocated for
 * @vaddr: The virtual address the page will be inserted into
 *
 * This function will allocate a page for a VMA that the caller knows will
 * be able to migrate in the future using move_pages() or reclaimed
 */
static inline struct page *
alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
					unsigned long vaddr)
{
	return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
}

static inline void clear_highpage(struct page *page)
{
	void *kaddr = kmap_atomic(page, KM_USER0);
	clear_page(kaddr);
	kunmap_atomic(kaddr, KM_USER0);
}

static inline void zero_user_segments(struct page *page,
	unsigned start1, unsigned end1,
	unsigned start2, unsigned end2)
{
	void *kaddr = kmap_atomic(page, KM_USER0);

	BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);

	if (end1 > start1)
		memset(kaddr + start1, 0, end1 - start1);

	if (end2 > start2)
		memset(kaddr + start2, 0, end2 - start2);

	kunmap_atomic(kaddr, KM_USER0);
	flush_dcache_page(page);
}

static inline void zero_user_segment(struct page *page,
	unsigned start, unsigned end)
{
	zero_user_segments(page, start, end, 0, 0);
}

static inline void zero_user(struct page *page,
	unsigned start, unsigned size)
{
	zero_user_segments(page, start, start + size, 0, 0);
}

static inline void __deprecated memclear_highpage_flush(struct page *page,
			unsigned int offset, unsigned int size)
{
	zero_user(page, offset, size);
}

#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE

static inline void copy_user_highpage(struct page *to, struct page *from,
	unsigned long vaddr, struct vm_area_struct *vma)
{
	char *vfrom, *vto;

	vfrom = kmap_atomic(from, KM_USER0);
	vto = kmap_atomic(to, KM_USER1);
	copy_user_page(vto, vfrom, vaddr, to);
	kunmap_atomic(vfrom, KM_USER0);
	kunmap_atomic(vto, KM_USER1);
}

#endif

static inline void copy_highpage(struct page *to, struct page *from)
{
	char *vfrom, *vto;

	vfrom = kmap_atomic(from, KM_USER0);
	vto = kmap_atomic(to, KM_USER1);
	copy_page(vto, vfrom);
	kunmap_atomic(vfrom, KM_USER0);
	kunmap_atomic(vto, KM_USER1);
}

#if defined(CONFIG_DEBUG_HIGHMEM) && defined(CONFIG_TRACE_IRQFLAGS_SUPPORT)

void debug_kmap_atomic(enum km_type type);

#else

static inline void debug_kmap_atomic(enum km_type type)
{
}

#endif

#endif /* _LINUX_HIGHMEM_H */