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
7#include <asm/cacheflush.h>
8
9#ifndef ARCH_HAS_FLUSH_ANON_PAGE
10static inline void flush_anon_page(struct page *page, unsigned long vmaddr)
11{
12}
13#endif
14
15#ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
16static inline void flush_kernel_dcache_page(struct page *page)
17{
18}
19#endif
20
21#ifdef CONFIG_HIGHMEM
22
23#include <asm/highmem.h>
24
25/* declarations for linux/mm/highmem.c */
26unsigned int nr_free_highpages(void);
27extern unsigned long totalhigh_pages;
28
29#else /* CONFIG_HIGHMEM */
30
31static inline unsigned int nr_free_highpages(void) { return 0; }
32
33#define totalhigh_pages 0
34
35#ifndef ARCH_HAS_KMAP
36static inline void *kmap(struct page *page)
37{
38 might_sleep();
39 return page_address(page);
40}
41
42#define kunmap(page) do { (void) (page); } while (0)
43
44#define kmap_atomic(page, idx) page_address(page)
45#define kunmap_atomic(addr, idx) do { } while (0)
46#define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn))
47#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
48#endif
49
50#endif /* CONFIG_HIGHMEM */
51
52/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
53static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
54{
55 void *addr = kmap_atomic(page, KM_USER0);
56 clear_user_page(addr, vaddr, page);
57 kunmap_atomic(addr, KM_USER0);
58 /* Make sure this page is cleared on other CPU's too before using it */
59 smp_wmb();
60}
61
62#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
63static inline struct page *
64alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr)
65{
66 struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr);
67
68 if (page)
69 clear_user_highpage(page, vaddr);
70
71 return page;
72}
73#endif
74
75static inline void clear_highpage(struct page *page)
76{
77 void *kaddr = kmap_atomic(page, KM_USER0);
78 clear_page(kaddr);
79 kunmap_atomic(kaddr, KM_USER0);
80}
81
82/*
83 * Same but also flushes aliased cache contents to RAM.
84 */
85static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size)
86{
87 void *kaddr;
88
89 BUG_ON(offset + size > PAGE_SIZE);
90
91 kaddr = kmap_atomic(page, KM_USER0);
92 memset((char *)kaddr + offset, 0, size);
93 flush_dcache_page(page);
94 kunmap_atomic(kaddr, KM_USER0);
95}
96
97static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr)
98{
99 char *vfrom, *vto;
100
101 vfrom = kmap_atomic(from, KM_USER0);
102 vto = kmap_atomic(to, KM_USER1);
103 copy_user_page(vto, vfrom, vaddr, to);
104 kunmap_atomic(vfrom, KM_USER0);
105 kunmap_atomic(vto, KM_USER1);
106 /* Make sure this page is cleared on other CPU's too before using it */
107 smp_wmb();
108}
109
110static inline void copy_highpage(struct page *to, struct page *from)
111{
112 char *vfrom, *vto;
113
114 vfrom = kmap_atomic(from, KM_USER0);
115 vto = kmap_atomic(to, KM_USER1);
116 copy_page(vto, vfrom);
117 kunmap_atomic(vfrom, KM_USER0);
118 kunmap_atomic(vto, KM_USER1);
119}
120
121#endif /* _LINUX_HIGHMEM_H */