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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 | |
11 | static inline void flush_anon_page(struct page *page, unsigned long vmaddr) | |
12 | { | |
13 | } | |
14 | #endif | |
15 | ||
16 | #ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE | |
17 | static 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 */ | |
27 | unsigned int nr_free_highpages(void); | |
28 | extern unsigned long totalhigh_pages; | |
29 | ||
30 | #else /* CONFIG_HIGHMEM */ | |
31 | ||
32 | static inline unsigned int nr_free_highpages(void) { return 0; } | |
33 | ||
34 | #define totalhigh_pages 0 | |
35 | ||
36 | #ifndef ARCH_HAS_KMAP | |
37 | static inline void *kmap(struct page *page) | |
38 | { | |
39 | might_sleep(); | |
40 | return page_address(page); | |
41 | } | |
42 | ||
43 | #define kunmap(page) do { (void) (page); } while (0) | |
44 | ||
45 | #define kmap_atomic(page, idx) \ | |
46 | ({ pagefault_disable(); page_address(page); }) | |
47 | #define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0) | |
48 | #define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx)) | |
49 | #define kmap_atomic_to_page(ptr) virt_to_page(ptr) | |
50 | #endif | |
51 | ||
52 | #endif /* CONFIG_HIGHMEM */ | |
53 | ||
54 | /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ | |
55 | static inline void clear_user_highpage(struct page *page, unsigned long vaddr) | |
56 | { | |
57 | void *addr = kmap_atomic(page, KM_USER0); | |
58 | clear_user_page(addr, vaddr, page); | |
59 | kunmap_atomic(addr, KM_USER0); | |
60 | /* Make sure this page is cleared on other CPU's too before using it */ | |
61 | smp_wmb(); | |
62 | } | |
63 | ||
64 | #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE | |
65 | static inline struct page * | |
66 | alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr) | |
67 | { | |
68 | struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr); | |
69 | ||
70 | if (page) | |
71 | clear_user_highpage(page, vaddr); | |
72 | ||
73 | return page; | |
74 | } | |
75 | #endif | |
76 | ||
77 | static inline void clear_highpage(struct page *page) | |
78 | { | |
79 | void *kaddr = kmap_atomic(page, KM_USER0); | |
80 | clear_page(kaddr); | |
81 | kunmap_atomic(kaddr, KM_USER0); | |
82 | } | |
83 | ||
84 | /* | |
85 | * Same but also flushes aliased cache contents to RAM. | |
86 | */ | |
87 | static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size) | |
88 | { | |
89 | void *kaddr; | |
90 | ||
91 | BUG_ON(offset + size > PAGE_SIZE); | |
92 | ||
93 | kaddr = kmap_atomic(page, KM_USER0); | |
94 | memset((char *)kaddr + offset, 0, size); | |
95 | flush_dcache_page(page); | |
96 | kunmap_atomic(kaddr, KM_USER0); | |
97 | } | |
98 | ||
99 | static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr) | |
100 | { | |
101 | char *vfrom, *vto; | |
102 | ||
103 | vfrom = kmap_atomic(from, KM_USER0); | |
104 | vto = kmap_atomic(to, KM_USER1); | |
105 | copy_user_page(vto, vfrom, vaddr, to); | |
106 | kunmap_atomic(vfrom, KM_USER0); | |
107 | kunmap_atomic(vto, KM_USER1); | |
108 | /* Make sure this page is cleared on other CPU's too before using it */ | |
109 | smp_wmb(); | |
110 | } | |
111 | ||
112 | static inline void copy_highpage(struct page *to, struct page *from) | |
113 | { | |
114 | char *vfrom, *vto; | |
115 | ||
116 | vfrom = kmap_atomic(from, KM_USER0); | |
117 | vto = kmap_atomic(to, KM_USER1); | |
118 | copy_page(vto, vfrom); | |
119 | kunmap_atomic(vfrom, KM_USER0); | |
120 | kunmap_atomic(vto, KM_USER1); | |
121 | } | |
122 | ||
123 | #endif /* _LINUX_HIGHMEM_H */ |