Linux v2.6.13-rc3
[pohmelfs.git] / include / linux / highmem.h
blob6bece9280eb779cf673e9f700ccc64ccc28d543a
1 #ifndef _LINUX_HIGHMEM_H
2 #define _LINUX_HIGHMEM_H
4 #include <linux/config.h>
5 #include <linux/fs.h>
6 #include <linux/mm.h>
8 #include <asm/cacheflush.h>
10 #ifdef CONFIG_HIGHMEM
12 #include <asm/highmem.h>
14 /* declarations for linux/mm/highmem.c */
15 unsigned int nr_free_highpages(void);
17 #else /* CONFIG_HIGHMEM */
19 static inline unsigned int nr_free_highpages(void) { return 0; }
21 static inline void *kmap(struct page *page)
23 might_sleep();
24 return page_address(page);
27 #define kunmap(page) do { (void) (page); } while (0)
29 #define kmap_atomic(page, idx) page_address(page)
30 #define kunmap_atomic(addr, idx) do { } while (0)
31 #define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn))
32 #define kmap_atomic_to_page(ptr) virt_to_page(ptr)
34 #endif /* CONFIG_HIGHMEM */
36 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
37 static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
39 void *addr = kmap_atomic(page, KM_USER0);
40 clear_user_page(addr, vaddr, page);
41 kunmap_atomic(addr, KM_USER0);
42 /* Make sure this page is cleared on other CPU's too before using it */
43 smp_wmb();
46 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
47 static inline struct page *
48 alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr)
50 struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr);
52 if (page)
53 clear_user_highpage(page, vaddr);
55 return page;
57 #endif
59 static inline void clear_highpage(struct page *page)
61 void *kaddr = kmap_atomic(page, KM_USER0);
62 clear_page(kaddr);
63 kunmap_atomic(kaddr, KM_USER0);
67 * Same but also flushes aliased cache contents to RAM.
69 static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size)
71 void *kaddr;
73 BUG_ON(offset + size > PAGE_SIZE);
75 kaddr = kmap_atomic(page, KM_USER0);
76 memset((char *)kaddr + offset, 0, size);
77 flush_dcache_page(page);
78 kunmap_atomic(kaddr, KM_USER0);
81 static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr)
83 char *vfrom, *vto;
85 vfrom = kmap_atomic(from, KM_USER0);
86 vto = kmap_atomic(to, KM_USER1);
87 copy_user_page(vto, vfrom, vaddr, to);
88 kunmap_atomic(vfrom, KM_USER0);
89 kunmap_atomic(vto, KM_USER1);
90 /* Make sure this page is cleared on other CPU's too before using it */
91 smp_wmb();
94 static inline void copy_highpage(struct page *to, struct page *from)
96 char *vfrom, *vto;
98 vfrom = kmap_atomic(from, KM_USER0);
99 vto = kmap_atomic(to, KM_USER1);
100 copy_page(vto, vfrom);
101 kunmap_atomic(vfrom, KM_USER0);
102 kunmap_atomic(vto, KM_USER1);
105 #endif /* _LINUX_HIGHMEM_H */