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 void kmap_flush_unused(void);
32 #else /* CONFIG_HIGHMEM */
34 static inline unsigned int nr_free_highpages(void) { return 0; }
36 #define totalhigh_pages 0
39 static inline void *kmap(struct page
*page
)
42 return page_address(page
);
45 #define kunmap(page) do { (void) (page); } while (0)
47 #include <asm/kmap_types.h>
49 static inline void *kmap_atomic(struct page
*page
, enum km_type idx
)
52 return page_address(page
);
54 #define kmap_atomic_prot(page, idx, prot) kmap_atomic(page, idx)
56 #define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0)
57 #define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx))
58 #define kmap_atomic_to_page(ptr) virt_to_page(ptr)
60 #define kmap_flush_unused() do {} while(0)
63 #endif /* CONFIG_HIGHMEM */
65 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
66 static inline void clear_user_highpage(struct page
*page
, unsigned long vaddr
)
68 void *addr
= kmap_atomic(page
, KM_USER0
);
69 clear_user_page(addr
, vaddr
, page
);
70 kunmap_atomic(addr
, KM_USER0
);
71 /* Make sure this page is cleared on other CPU's too before using it */
75 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
76 static inline struct page
*
77 alloc_zeroed_user_highpage(struct vm_area_struct
*vma
, unsigned long vaddr
)
79 struct page
*page
= alloc_page_vma(GFP_HIGHUSER
, vma
, vaddr
);
82 clear_user_highpage(page
, vaddr
);
88 static inline void clear_highpage(struct page
*page
)
90 void *kaddr
= kmap_atomic(page
, KM_USER0
);
92 kunmap_atomic(kaddr
, KM_USER0
);
96 * Same but also flushes aliased cache contents to RAM.
98 static inline void memclear_highpage_flush(struct page
*page
, unsigned int offset
, unsigned int size
)
102 BUG_ON(offset
+ size
> PAGE_SIZE
);
104 kaddr
= kmap_atomic(page
, KM_USER0
);
105 memset((char *)kaddr
+ offset
, 0, size
);
106 flush_dcache_page(page
);
107 kunmap_atomic(kaddr
, KM_USER0
);
110 #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
112 static inline void copy_user_highpage(struct page
*to
, struct page
*from
,
113 unsigned long vaddr
, struct vm_area_struct
*vma
)
117 vfrom
= kmap_atomic(from
, KM_USER0
);
118 vto
= kmap_atomic(to
, KM_USER1
);
119 copy_user_page(vto
, vfrom
, vaddr
, to
);
120 kunmap_atomic(vfrom
, KM_USER0
);
121 kunmap_atomic(vto
, KM_USER1
);
122 /* Make sure this page is cleared on other CPU's too before using it */
128 static inline void copy_highpage(struct page
*to
, struct page
*from
)
132 vfrom
= kmap_atomic(from
, KM_USER0
);
133 vto
= kmap_atomic(to
, KM_USER1
);
134 copy_page(vto
, vfrom
);
135 kunmap_atomic(vfrom
, KM_USER0
);
136 kunmap_atomic(vto
, KM_USER1
);
139 #endif /* _LINUX_HIGHMEM_H */