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[PATCH] Add API for flushing Anon pages
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1#ifndef _LINUX_HIGHMEM_H
2#define _LINUX_HIGHMEM_H
3
4#include <linux/config.h>
5#include <linux/fs.h>
6#include <linux/mm.h>
7
8#include <asm/cacheflush.h>
9
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10#ifndef ARCH_HAS_FLUSH_ANON_PAGE
11static inline void flush_anon_page(struct page *page, unsigned long vmaddr)
12{
13}
14#endif
15
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16#ifdef CONFIG_HIGHMEM
17
18#include <asm/highmem.h>
19
20/* declarations for linux/mm/highmem.c */
21unsigned int nr_free_highpages(void);
22
23#else /* CONFIG_HIGHMEM */
24
25static inline unsigned int nr_free_highpages(void) { return 0; }
26
27static inline void *kmap(struct page *page)
28{
29 might_sleep();
30 return page_address(page);
31}
32
33#define kunmap(page) do { (void) (page); } while (0)
34
35#define kmap_atomic(page, idx) page_address(page)
36#define kunmap_atomic(addr, idx) do { } while (0)
60e64d46 37#define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn))
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38#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
39
40#endif /* CONFIG_HIGHMEM */
41
42/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
43static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
44{
45 void *addr = kmap_atomic(page, KM_USER0);
46 clear_user_page(addr, vaddr, page);
47 kunmap_atomic(addr, KM_USER0);
48 /* Make sure this page is cleared on other CPU's too before using it */
49 smp_wmb();
50}
51
52#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
53static inline struct page *
54alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr)
55{
56 struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr);
57
58 if (page)
59 clear_user_highpage(page, vaddr);
60
61 return page;
62}
63#endif
64
65static inline void clear_highpage(struct page *page)
66{
67 void *kaddr = kmap_atomic(page, KM_USER0);
68 clear_page(kaddr);
69 kunmap_atomic(kaddr, KM_USER0);
70}
71
72/*
73 * Same but also flushes aliased cache contents to RAM.
74 */
75static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size)
76{
77 void *kaddr;
78
79 BUG_ON(offset + size > PAGE_SIZE);
80
81 kaddr = kmap_atomic(page, KM_USER0);
82 memset((char *)kaddr + offset, 0, size);
83 flush_dcache_page(page);
84 kunmap_atomic(kaddr, KM_USER0);
85}
86
87static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr)
88{
89 char *vfrom, *vto;
90
91 vfrom = kmap_atomic(from, KM_USER0);
92 vto = kmap_atomic(to, KM_USER1);
93 copy_user_page(vto, vfrom, vaddr, to);
94 kunmap_atomic(vfrom, KM_USER0);
95 kunmap_atomic(vto, KM_USER1);
96 /* Make sure this page is cleared on other CPU's too before using it */
97 smp_wmb();
98}
99
100static inline void copy_highpage(struct page *to, struct page *from)
101{
102 char *vfrom, *vto;
103
104 vfrom = kmap_atomic(from, KM_USER0);
105 vto = kmap_atomic(to, KM_USER1);
106 copy_page(vto, vfrom);
107 kunmap_atomic(vfrom, KM_USER0);
108 kunmap_atomic(vto, KM_USER1);
109}
110
111#endif /* _LINUX_HIGHMEM_H */