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1da177e4 LT |
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 | ||
10 | #ifdef CONFIG_HIGHMEM | |
11 | ||
12 | #include <asm/highmem.h> | |
13 | ||
14 | /* declarations for linux/mm/highmem.c */ | |
15 | unsigned int nr_free_highpages(void); | |
16 | ||
17 | #else /* CONFIG_HIGHMEM */ | |
18 | ||
19 | static inline unsigned int nr_free_highpages(void) { return 0; } | |
20 | ||
21 | static inline void *kmap(struct page *page) | |
22 | { | |
23 | might_sleep(); | |
24 | return page_address(page); | |
25 | } | |
26 | ||
27 | #define kunmap(page) do { (void) (page); } while (0) | |
28 | ||
29 | #define kmap_atomic(page, idx) page_address(page) | |
30 | #define kunmap_atomic(addr, idx) do { } while (0) | |
31 | #define kmap_atomic_to_page(ptr) virt_to_page(ptr) | |
32 | ||
33 | #endif /* CONFIG_HIGHMEM */ | |
34 | ||
35 | /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ | |
36 | static inline void clear_user_highpage(struct page *page, unsigned long vaddr) | |
37 | { | |
38 | void *addr = kmap_atomic(page, KM_USER0); | |
39 | clear_user_page(addr, vaddr, page); | |
40 | kunmap_atomic(addr, KM_USER0); | |
41 | /* Make sure this page is cleared on other CPU's too before using it */ | |
42 | smp_wmb(); | |
43 | } | |
44 | ||
45 | #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE | |
46 | static inline struct page * | |
47 | alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr) | |
48 | { | |
49 | struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr); | |
50 | ||
51 | if (page) | |
52 | clear_user_highpage(page, vaddr); | |
53 | ||
54 | return page; | |
55 | } | |
56 | #endif | |
57 | ||
58 | static inline void clear_highpage(struct page *page) | |
59 | { | |
60 | void *kaddr = kmap_atomic(page, KM_USER0); | |
61 | clear_page(kaddr); | |
62 | kunmap_atomic(kaddr, KM_USER0); | |
63 | } | |
64 | ||
65 | /* | |
66 | * Same but also flushes aliased cache contents to RAM. | |
67 | */ | |
68 | static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size) | |
69 | { | |
70 | void *kaddr; | |
71 | ||
72 | BUG_ON(offset + size > PAGE_SIZE); | |
73 | ||
74 | kaddr = kmap_atomic(page, KM_USER0); | |
75 | memset((char *)kaddr + offset, 0, size); | |
76 | flush_dcache_page(page); | |
77 | kunmap_atomic(kaddr, KM_USER0); | |
78 | } | |
79 | ||
80 | static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr) | |
81 | { | |
82 | char *vfrom, *vto; | |
83 | ||
84 | vfrom = kmap_atomic(from, KM_USER0); | |
85 | vto = kmap_atomic(to, KM_USER1); | |
86 | copy_user_page(vto, vfrom, vaddr, to); | |
87 | kunmap_atomic(vfrom, KM_USER0); | |
88 | kunmap_atomic(vto, KM_USER1); | |
89 | /* Make sure this page is cleared on other CPU's too before using it */ | |
90 | smp_wmb(); | |
91 | } | |
92 | ||
93 | static inline void copy_highpage(struct page *to, struct page *from) | |
94 | { | |
95 | char *vfrom, *vto; | |
96 | ||
97 | vfrom = kmap_atomic(from, KM_USER0); | |
98 | vto = kmap_atomic(to, KM_USER1); | |
99 | copy_page(vto, vfrom); | |
100 | kunmap_atomic(vfrom, KM_USER0); | |
101 | kunmap_atomic(vto, KM_USER1); | |
102 | } | |
103 | ||
104 | #endif /* _LINUX_HIGHMEM_H */ |