1 #ifndef _LINUX_HIGHMEM_H
2 #define _LINUX_HIGHMEM_H
6 #include <linux/uaccess.h>
8 #include <asm/cacheflush.h>
10 #ifndef ARCH_HAS_FLUSH_ANON_PAGE
11 static inline void flush_anon_page(struct vm_area_struct
*vma
, struct page
*page
, unsigned long vmaddr
)
16 #ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
17 static inline void flush_kernel_dcache_page(struct page
*page
)
24 #include <asm/highmem.h>
26 /* declarations for linux/mm/highmem.c */
27 unsigned int nr_free_highpages(void);
28 extern unsigned long totalhigh_pages
;
30 #else /* CONFIG_HIGHMEM */
32 static inline unsigned int nr_free_highpages(void) { return 0; }
34 #define totalhigh_pages 0
37 static inline void *kmap(struct page
*page
)
40 return page_address(page
);
43 #define kunmap(page) do { (void) (page); } while (0)
45 #include <asm/kmap_types.h>
47 static inline void *kmap_atomic(struct page
*page
, enum km_type idx
)
50 return page_address(page
);
53 #define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0)
54 #define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx))
55 #define kmap_atomic_to_page(ptr) virt_to_page(ptr)
58 #endif /* CONFIG_HIGHMEM */
60 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
61 static inline void clear_user_highpage(struct page
*page
, unsigned long vaddr
)
63 void *addr
= kmap_atomic(page
, KM_USER0
);
64 clear_user_page(addr
, vaddr
, page
);
65 kunmap_atomic(addr
, KM_USER0
);
66 /* Make sure this page is cleared on other CPU's too before using it */
70 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
71 static inline struct page
*
72 alloc_zeroed_user_highpage(struct vm_area_struct
*vma
, unsigned long vaddr
)
74 struct page
*page
= alloc_page_vma(GFP_HIGHUSER
, vma
, vaddr
);
77 clear_user_highpage(page
, vaddr
);
83 static inline void clear_highpage(struct page
*page
)
85 void *kaddr
= kmap_atomic(page
, KM_USER0
);
87 kunmap_atomic(kaddr
, KM_USER0
);
91 * Same but also flushes aliased cache contents to RAM.
93 static inline void memclear_highpage_flush(struct page
*page
, unsigned int offset
, unsigned int size
)
97 BUG_ON(offset
+ size
> PAGE_SIZE
);
99 kaddr
= kmap_atomic(page
, KM_USER0
);
100 memset((char *)kaddr
+ offset
, 0, size
);
101 flush_dcache_page(page
);
102 kunmap_atomic(kaddr
, KM_USER0
);
105 #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
107 static inline void copy_user_highpage(struct page
*to
, struct page
*from
,
108 unsigned long vaddr
, struct vm_area_struct
*vma
)
112 vfrom
= kmap_atomic(from
, KM_USER0
);
113 vto
= kmap_atomic(to
, KM_USER1
);
114 copy_user_page(vto
, vfrom
, vaddr
, to
);
115 kunmap_atomic(vfrom
, KM_USER0
);
116 kunmap_atomic(vto
, KM_USER1
);
117 /* Make sure this page is cleared on other CPU's too before using it */
123 static inline void copy_highpage(struct page
*to
, struct page
*from
)
127 vfrom
= kmap_atomic(from
, KM_USER0
);
128 vto
= kmap_atomic(to
, KM_USER1
);
129 copy_page(vto
, vfrom
);
130 kunmap_atomic(vfrom
, KM_USER0
);
131 kunmap_atomic(vto
, KM_USER1
);
134 #endif /* _LINUX_HIGHMEM_H */