Linux kernel mirror (for testing)
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linux
1#ifndef _LINUX_HIGHMEM_H
2#define _LINUX_HIGHMEM_H
3
4#include <linux/fs.h>
5#include <linux/mm.h>
6#include <linux/uaccess.h>
7
8#include <asm/cacheflush.h>
9
10#ifndef ARCH_HAS_FLUSH_ANON_PAGE
11static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
12{
13}
14#endif
15
16#ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
17static inline void flush_kernel_dcache_page(struct page *page)
18{
19}
20#endif
21
22#ifdef CONFIG_HIGHMEM
23
24#include <asm/highmem.h>
25
26/* declarations for linux/mm/highmem.c */
27unsigned int nr_free_highpages(void);
28extern unsigned long totalhigh_pages;
29
30void kmap_flush_unused(void);
31
32#else /* CONFIG_HIGHMEM */
33
34static inline unsigned int nr_free_highpages(void) { return 0; }
35
36#define totalhigh_pages 0
37
38#ifndef ARCH_HAS_KMAP
39static inline void *kmap(struct page *page)
40{
41 might_sleep();
42 return page_address(page);
43}
44
45#define kunmap(page) do { (void) (page); } while (0)
46
47#include <asm/kmap_types.h>
48
49static inline void *kmap_atomic(struct page *page, enum km_type idx)
50{
51 pagefault_disable();
52 return page_address(page);
53}
54#define kmap_atomic_prot(page, idx, prot) kmap_atomic(page, idx)
55
56#define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0)
57#define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx))
58#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
59
60#define kmap_flush_unused() do {} while(0)
61#endif
62
63#endif /* CONFIG_HIGHMEM */
64
65/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
66static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
67{
68 void *addr = kmap_atomic(page, KM_USER0);
69 clear_user_page(addr, vaddr, page);
70 kunmap_atomic(addr, KM_USER0);
71}
72
73#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
74/**
75 * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
76 * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
77 * @vma: The VMA the page is to be allocated for
78 * @vaddr: The virtual address the page will be inserted into
79 *
80 * This function will allocate a page for a VMA but the caller is expected
81 * to specify via movableflags whether the page will be movable in the
82 * future or not
83 *
84 * An architecture may override this function by defining
85 * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
86 * implementation.
87 */
88static inline struct page *
89__alloc_zeroed_user_highpage(gfp_t movableflags,
90 struct vm_area_struct *vma,
91 unsigned long vaddr)
92{
93 struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
94 vma, vaddr);
95
96 if (page)
97 clear_user_highpage(page, vaddr);
98
99 return page;
100}
101#endif
102
103/**
104 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
105 * @vma: The VMA the page is to be allocated for
106 * @vaddr: The virtual address the page will be inserted into
107 *
108 * This function will allocate a page for a VMA that the caller knows will
109 * be able to migrate in the future using move_pages() or reclaimed
110 */
111static inline struct page *
112alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
113 unsigned long vaddr)
114{
115 return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
116}
117
118static inline void clear_highpage(struct page *page)
119{
120 void *kaddr = kmap_atomic(page, KM_USER0);
121 clear_page(kaddr);
122 kunmap_atomic(kaddr, KM_USER0);
123}
124
125static inline void zero_user_segments(struct page *page,
126 unsigned start1, unsigned end1,
127 unsigned start2, unsigned end2)
128{
129 void *kaddr = kmap_atomic(page, KM_USER0);
130
131 BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);
132
133 if (end1 > start1)
134 memset(kaddr + start1, 0, end1 - start1);
135
136 if (end2 > start2)
137 memset(kaddr + start2, 0, end2 - start2);
138
139 kunmap_atomic(kaddr, KM_USER0);
140 flush_dcache_page(page);
141}
142
143static inline void zero_user_segment(struct page *page,
144 unsigned start, unsigned end)
145{
146 zero_user_segments(page, start, end, 0, 0);
147}
148
149static inline void zero_user(struct page *page,
150 unsigned start, unsigned size)
151{
152 zero_user_segments(page, start, start + size, 0, 0);
153}
154
155static inline void __deprecated memclear_highpage_flush(struct page *page,
156 unsigned int offset, unsigned int size)
157{
158 zero_user(page, offset, size);
159}
160
161#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
162
163static inline void copy_user_highpage(struct page *to, struct page *from,
164 unsigned long vaddr, struct vm_area_struct *vma)
165{
166 char *vfrom, *vto;
167
168 vfrom = kmap_atomic(from, KM_USER0);
169 vto = kmap_atomic(to, KM_USER1);
170 copy_user_page(vto, vfrom, vaddr, to);
171 kunmap_atomic(vfrom, KM_USER0);
172 kunmap_atomic(vto, KM_USER1);
173}
174
175#endif
176
177static inline void copy_highpage(struct page *to, struct page *from)
178{
179 char *vfrom, *vto;
180
181 vfrom = kmap_atomic(from, KM_USER0);
182 vto = kmap_atomic(to, KM_USER1);
183 copy_page(vto, vfrom);
184 kunmap_atomic(vfrom, KM_USER0);
185 kunmap_atomic(vto, KM_USER1);
186}
187
188#endif /* _LINUX_HIGHMEM_H */