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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) | |
60e64d46 | 31 | #define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn)) |
1da177e4 LT |
32 | #define kmap_atomic_to_page(ptr) virt_to_page(ptr) |
33 | ||
34 | #endif /* CONFIG_HIGHMEM */ | |
35 | ||
36 | /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ | |
37 | static inline void clear_user_highpage(struct page *page, unsigned long vaddr) | |
38 | { | |
39 | void *addr = kmap_atomic(page, KM_USER0); | |
40 | clear_user_page(addr, vaddr, page); | |
41 | kunmap_atomic(addr, KM_USER0); | |
42 | /* Make sure this page is cleared on other CPU's too before using it */ | |
43 | smp_wmb(); | |
44 | } | |
45 | ||
46 | #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE | |
47 | static inline struct page * | |
48 | alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr) | |
49 | { | |
50 | struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr); | |
51 | ||
52 | if (page) | |
53 | clear_user_highpage(page, vaddr); | |
54 | ||
55 | return page; | |
56 | } | |
57 | #endif | |
58 | ||
59 | static inline void clear_highpage(struct page *page) | |
60 | { | |
61 | void *kaddr = kmap_atomic(page, KM_USER0); | |
62 | clear_page(kaddr); | |
63 | kunmap_atomic(kaddr, KM_USER0); | |
64 | } | |
65 | ||
66 | /* | |
67 | * Same but also flushes aliased cache contents to RAM. | |
68 | */ | |
69 | static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size) | |
70 | { | |
71 | void *kaddr; | |
72 | ||
73 | BUG_ON(offset + size > PAGE_SIZE); | |
74 | ||
75 | kaddr = kmap_atomic(page, KM_USER0); | |
76 | memset((char *)kaddr + offset, 0, size); | |
77 | flush_dcache_page(page); | |
78 | kunmap_atomic(kaddr, KM_USER0); | |
79 | } | |
80 | ||
81 | static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr) | |
82 | { | |
83 | char *vfrom, *vto; | |
84 | ||
85 | vfrom = kmap_atomic(from, KM_USER0); | |
86 | vto = kmap_atomic(to, KM_USER1); | |
87 | copy_user_page(vto, vfrom, vaddr, to); | |
88 | kunmap_atomic(vfrom, KM_USER0); | |
89 | kunmap_atomic(vto, KM_USER1); | |
90 | /* Make sure this page is cleared on other CPU's too before using it */ | |
91 | smp_wmb(); | |
92 | } | |
93 | ||
94 | static inline void copy_highpage(struct page *to, struct page *from) | |
95 | { | |
96 | char *vfrom, *vto; | |
97 | ||
98 | vfrom = kmap_atomic(from, KM_USER0); | |
99 | vto = kmap_atomic(to, KM_USER1); | |
100 | copy_page(vto, vfrom); | |
101 | kunmap_atomic(vfrom, KM_USER0); | |
102 | kunmap_atomic(vto, KM_USER1); | |
103 | } | |
104 | ||
105 | #endif /* _LINUX_HIGHMEM_H */ |