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 /* Make sure this page is cleared on other CPU's too before using it */
72 smp_wmb();
73}
74
75#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
76static inline struct page *
77alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr)
78{
79 struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr);
80
81 if (page)
82 clear_user_highpage(page, vaddr);
83
84 return page;
85}
86#endif
87
88static inline void clear_highpage(struct page *page)
89{
90 void *kaddr = kmap_atomic(page, KM_USER0);
91 clear_page(kaddr);
92 kunmap_atomic(kaddr, KM_USER0);
93}
94
95/*
96 * Same but also flushes aliased cache contents to RAM.
97 *
98 * This must be a macro because KM_USER0 and friends aren't defined if
99 * !CONFIG_HIGHMEM
100 */
101#define zero_user_page(page, offset, size, km_type) \
102 do { \
103 void *kaddr; \
104 \
105 BUG_ON((offset) + (size) > PAGE_SIZE); \
106 \
107 kaddr = kmap_atomic(page, km_type); \
108 memset((char *)kaddr + (offset), 0, (size)); \
109 flush_dcache_page(page); \
110 kunmap_atomic(kaddr, (km_type)); \
111 } while (0)
112
113static inline void __deprecated memclear_highpage_flush(struct page *page,
114 unsigned int offset, unsigned int size)
115{
116 zero_user_page(page, offset, size, KM_USER0);
117}
118
119#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
120
121static inline void copy_user_highpage(struct page *to, struct page *from,
122 unsigned long vaddr, struct vm_area_struct *vma)
123{
124 char *vfrom, *vto;
125
126 vfrom = kmap_atomic(from, KM_USER0);
127 vto = kmap_atomic(to, KM_USER1);
128 copy_user_page(vto, vfrom, vaddr, to);
129 kunmap_atomic(vfrom, KM_USER0);
130 kunmap_atomic(vto, KM_USER1);
131 /* Make sure this page is cleared on other CPU's too before using it */
132 smp_wmb();
133}
134
135#endif
136
137static inline void copy_highpage(struct page *to, struct page *from)
138{
139 char *vfrom, *vto;
140
141 vfrom = kmap_atomic(from, KM_USER0);
142 vto = kmap_atomic(to, KM_USER1);
143 copy_page(vto, vfrom);
144 kunmap_atomic(vfrom, KM_USER0);
145 kunmap_atomic(vto, KM_USER1);
146}
147
148#endif /* _LINUX_HIGHMEM_H */