ia64/xen-unstable

view linux-2.6-xen-sparse/include/linux/highmem.h @ 8534:da7873110bbb

Tiny bootstrap cleanup.

Signed-off-by: Keir Fraser <keir@xensource.com>
author kaf24@firebug.cl.cam.ac.uk
date Mon Jan 09 19:46:46 2006 +0100 (2006-01-09)
parents 06d84bf87159
children fd9b2c1bb577
line source
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);
16 void kmap_flush_unused(void);
18 #else /* CONFIG_HIGHMEM */
20 static inline unsigned int nr_free_highpages(void) { return 0; }
21 static inline void kmap_flush_unused(void) { }
23 static inline void *kmap(struct page *page)
24 {
25 might_sleep();
26 return page_address(page);
27 }
29 #define kunmap(page) do { (void) (page); } while (0)
31 #define kmap_atomic(page, idx) page_address(page)
32 #define kunmap_atomic(addr, idx) do { } while (0)
33 #define kmap_atomic_to_page(ptr) virt_to_page(ptr)
35 #endif /* CONFIG_HIGHMEM */
37 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
38 static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
39 {
40 void *addr = kmap_atomic(page, KM_USER0);
41 clear_user_page(addr, vaddr, page);
42 kunmap_atomic(addr, KM_USER0);
43 /* Make sure this page is cleared on other CPU's too before using it */
44 smp_wmb();
45 }
47 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
48 static inline struct page *
49 alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr)
50 {
51 struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr);
53 if (page)
54 clear_user_highpage(page, vaddr);
56 return page;
57 }
58 #endif
60 static inline void clear_highpage(struct page *page)
61 {
62 void *kaddr = kmap_atomic(page, KM_USER0);
63 clear_page(kaddr);
64 kunmap_atomic(kaddr, KM_USER0);
65 }
67 /*
68 * Same but also flushes aliased cache contents to RAM.
69 */
70 static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size)
71 {
72 void *kaddr;
74 BUG_ON(offset + size > PAGE_SIZE);
76 kaddr = kmap_atomic(page, KM_USER0);
77 memset((char *)kaddr + offset, 0, size);
78 flush_dcache_page(page);
79 kunmap_atomic(kaddr, KM_USER0);
80 }
82 static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr)
83 {
84 char *vfrom, *vto;
86 vfrom = kmap_atomic(from, KM_USER0);
87 vto = kmap_atomic(to, KM_USER1);
88 copy_user_page(vto, vfrom, vaddr, to);
89 kunmap_atomic(vfrom, KM_USER0);
90 kunmap_atomic(vto, KM_USER1);
91 /* Make sure this page is cleared on other CPU's too before using it */
92 smp_wmb();
93 }
95 static inline void copy_highpage(struct page *to, struct page *from)
96 {
97 char *vfrom, *vto;
99 vfrom = kmap_atomic(from, KM_USER0);
100 vto = kmap_atomic(to, KM_USER1);
101 copy_page(vto, vfrom);
102 kunmap_atomic(vfrom, KM_USER0);
103 kunmap_atomic(vto, KM_USER1);
104 }
106 #endif /* _LINUX_HIGHMEM_H */