1 #ifndef _LINUX_HIGHMEM_H
2 #define _LINUX_HIGHMEM_H
7 #include <asm/cacheflush.h>
9 #ifndef ARCH_HAS_FLUSH_ANON_PAGE
10 static inline void flush_anon_page(struct page *page, unsigned long vmaddr)
15 #ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
16 static inline void flush_kernel_dcache_page(struct page *page)
23 #include <asm/highmem.h>
25 /* declarations for linux/mm/highmem.c */
26 unsigned int nr_free_highpages(void);
28 #else /* CONFIG_HIGHMEM */
30 static inline unsigned int nr_free_highpages(void) { return 0; }
33 static inline void *kmap(struct page *page)
36 return page_address(page);
39 #define kunmap(page) do { (void) (page); } while (0)
41 #define kmap_atomic(page, idx) page_address(page)
42 #define kunmap_atomic(addr, idx) do { } while (0)
43 #define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn))
44 #define kmap_atomic_to_page(ptr) virt_to_page(ptr)
47 #endif /* CONFIG_HIGHMEM */
49 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
50 static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
52 void *addr = kmap_atomic(page, KM_USER0);
53 clear_user_page(addr, vaddr, page);
54 kunmap_atomic(addr, KM_USER0);
55 /* Make sure this page is cleared on other CPU's too before using it */
59 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
60 static inline struct page *
61 alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr)
63 struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr);
66 clear_user_highpage(page, vaddr);
72 static inline void clear_highpage(struct page *page)
74 void *kaddr = kmap_atomic(page, KM_USER0);
76 kunmap_atomic(kaddr, KM_USER0);
80 * Same but also flushes aliased cache contents to RAM.
82 static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size)
86 BUG_ON(offset + size > PAGE_SIZE);
88 kaddr = kmap_atomic(page, KM_USER0);
89 memset((char *)kaddr + offset, 0, size);
90 flush_dcache_page(page);
91 kunmap_atomic(kaddr, KM_USER0);
94 static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr)
98 vfrom = kmap_atomic(from, KM_USER0);
99 vto = kmap_atomic(to, KM_USER1);
100 copy_user_page(vto, vfrom, vaddr, to);
101 kunmap_atomic(vfrom, KM_USER0);
102 kunmap_atomic(vto, KM_USER1);
103 /* Make sure this page is cleared on other CPU's too before using it */
107 static inline void copy_highpage(struct page *to, struct page *from)
111 vfrom = kmap_atomic(from, KM_USER0);
112 vto = kmap_atomic(to, KM_USER1);
113 copy_page(vto, vfrom);
114 kunmap_atomic(vfrom, KM_USER0);
115 kunmap_atomic(vto, KM_USER1);
118 #endif /* _LINUX_HIGHMEM_H */