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