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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_HIGHMEM_H
2#define _LINUX_HIGHMEM_H
3
Linus Torvalds1da177e2005-04-16 15:20:36 -07004#include <linux/fs.h>
5#include <linux/mm.h>
Peter Zijlstraad76fb62006-12-06 20:32:21 -08006#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007
8#include <asm/cacheflush.h>
9
James Bottomley03beb072006-03-26 01:36:57 -080010#ifndef ARCH_HAS_FLUSH_ANON_PAGE
Russell Kinga6f36be2006-12-30 22:24:19 +000011static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
James Bottomley03beb072006-03-26 01:36:57 -080012{
13}
14#endif
15
James Bottomley5a3a5a92006-03-26 01:36:59 -080016#ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
17static inline void flush_kernel_dcache_page(struct page *page)
18{
19}
20#endif
21
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#ifdef CONFIG_HIGHMEM
23
24#include <asm/highmem.h>
25
26/* declarations for linux/mm/highmem.c */
27unsigned int nr_free_highpages(void);
Christoph Lameterc1f60a52006-09-25 23:31:11 -070028extern unsigned long totalhigh_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
Jeremy Fitzhardingece6234b2007-05-02 19:27:15 +020030void kmap_flush_unused(void);
31
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#else /* CONFIG_HIGHMEM */
33
34static inline unsigned int nr_free_highpages(void) { return 0; }
35
Christoph Lameterc1f60a52006-09-25 23:31:11 -070036#define totalhigh_pages 0
37
James Bottomleya6ca1b92006-09-25 23:30:55 -070038#ifndef ARCH_HAS_KMAP
Linus Torvalds1da177e2005-04-16 15:20:36 -070039static inline void *kmap(struct page *page)
40{
41 might_sleep();
42 return page_address(page);
43}
44
45#define kunmap(page) do { (void) (page); } while (0)
46
Geert Uytterhoeven254f9c52007-05-01 22:33:07 +020047#include <asm/kmap_types.h>
48
49static inline void *kmap_atomic(struct page *page, enum km_type idx)
50{
51 pagefault_disable();
52 return page_address(page);
53}
Jeremy Fitzhardingece6234b2007-05-02 19:27:15 +020054#define kmap_atomic_prot(page, idx, prot) kmap_atomic(page, idx)
Geert Uytterhoeven254f9c52007-05-01 22:33:07 +020055
Peter Zijlstraad76fb62006-12-06 20:32:21 -080056#define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0)
57#define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx))
Linus Torvalds1da177e2005-04-16 15:20:36 -070058#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
Jeremy Fitzhardingece6234b2007-05-02 19:27:15 +020059
60#define kmap_flush_unused() do {} while(0)
James Bottomleya6ca1b92006-09-25 23:30:55 -070061#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
63#endif /* CONFIG_HIGHMEM */
64
65/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
66static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
67{
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 */
72 smp_wmb();
73}
74
75#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
Mel Gorman769848c2007-07-17 04:03:05 -070076/**
77 * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
78 * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
79 * @vma: The VMA the page is to be allocated for
80 * @vaddr: The virtual address the page will be inserted into
81 *
82 * This function will allocate a page for a VMA but the caller is expected
83 * to specify via movableflags whether the page will be movable in the
84 * future or not
85 *
86 * An architecture may override this function by defining
87 * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
88 * implementation.
89 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070090static inline struct page *
Mel Gorman769848c2007-07-17 04:03:05 -070091__alloc_zeroed_user_highpage(gfp_t movableflags,
92 struct vm_area_struct *vma,
93 unsigned long vaddr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070094{
Mel Gorman769848c2007-07-17 04:03:05 -070095 struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
96 vma, vaddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
98 if (page)
99 clear_user_highpage(page, vaddr);
100
101 return page;
102}
103#endif
104
Mel Gorman769848c2007-07-17 04:03:05 -0700105/**
106 * alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA
107 * @vma: The VMA the page is to be allocated for
108 * @vaddr: The virtual address the page will be inserted into
109 *
110 * This function will allocate a page for a VMA that the caller knows will
111 * not be able to move in the future using move_pages() or reclaim. If it
112 * is known that the page can move, use alloc_zeroed_user_highpage_movable
113 */
114static inline struct page *
115alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr)
116{
117 return __alloc_zeroed_user_highpage(0, vma, vaddr);
118}
119
120/**
121 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
122 * @vma: The VMA the page is to be allocated for
123 * @vaddr: The virtual address the page will be inserted into
124 *
125 * This function will allocate a page for a VMA that the caller knows will
126 * be able to migrate in the future using move_pages() or reclaimed
127 */
128static inline struct page *
129alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
130 unsigned long vaddr)
131{
132 return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
133}
134
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135static inline void clear_highpage(struct page *page)
136{
137 void *kaddr = kmap_atomic(page, KM_USER0);
138 clear_page(kaddr);
139 kunmap_atomic(kaddr, KM_USER0);
140}
141
142/*
143 * Same but also flushes aliased cache contents to RAM.
Nate Diller01f27052007-05-09 02:35:07 -0700144 *
145 * This must be a macro because KM_USER0 and friends aren't defined if
146 * !CONFIG_HIGHMEM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 */
Nate Diller01f27052007-05-09 02:35:07 -0700148#define zero_user_page(page, offset, size, km_type) \
149 do { \
150 void *kaddr; \
151 \
152 BUG_ON((offset) + (size) > PAGE_SIZE); \
153 \
154 kaddr = kmap_atomic(page, km_type); \
155 memset((char *)kaddr + (offset), 0, (size)); \
156 flush_dcache_page(page); \
157 kunmap_atomic(kaddr, (km_type)); \
158 } while (0)
159
Nate Dillerf37bc272007-05-09 02:35:09 -0700160static inline void __deprecated memclear_highpage_flush(struct page *page,
Nate Diller01f27052007-05-09 02:35:07 -0700161 unsigned int offset, unsigned int size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162{
Nate Diller01f27052007-05-09 02:35:07 -0700163 zero_user_page(page, offset, size, KM_USER0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164}
165
Atsushi Nemoto77fff4a2006-12-12 17:14:54 +0000166#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
167
Atsushi Nemoto9de455b2006-12-12 17:14:55 +0000168static inline void copy_user_highpage(struct page *to, struct page *from,
169 unsigned long vaddr, struct vm_area_struct *vma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170{
171 char *vfrom, *vto;
172
173 vfrom = kmap_atomic(from, KM_USER0);
174 vto = kmap_atomic(to, KM_USER1);
175 copy_user_page(vto, vfrom, vaddr, to);
176 kunmap_atomic(vfrom, KM_USER0);
177 kunmap_atomic(vto, KM_USER1);
178 /* Make sure this page is cleared on other CPU's too before using it */
179 smp_wmb();
180}
181
Atsushi Nemoto77fff4a2006-12-12 17:14:54 +0000182#endif
183
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184static inline void copy_highpage(struct page *to, struct page *from)
185{
186 char *vfrom, *vto;
187
188 vfrom = kmap_atomic(from, KM_USER0);
189 vto = kmap_atomic(to, KM_USER1);
190 copy_page(vto, vfrom);
191 kunmap_atomic(vfrom, KM_USER0);
192 kunmap_atomic(vto, KM_USER1);
193}
194
195#endif /* _LINUX_HIGHMEM_H */