1 #ifndef _LINUX_HIGHMEM_H
2 #define _LINUX_HIGHMEM_H
3
4 #include <linux/fs.h>
5 #include <linux/mm.h>
6 #include <linux/uaccess.h>
7
8 #include <asm/cacheflush.h>
9
10 #ifndef ARCH_HAS_FLUSH_ANON_PAGE
flush_anon_page(struct vm_area_struct * vma,struct page * page,unsigned long vmaddr)11 static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
12 {
13 }
14 #endif
15
16 #ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
flush_kernel_dcache_page(struct page * page)17 static inline void flush_kernel_dcache_page(struct page *page)
18 {
19 }
20 #endif
21
22 #ifdef CONFIG_HIGHMEM
23
24 #include <asm/highmem.h>
25
26 /* declarations for linux/mm/highmem.c */
27 unsigned int nr_free_highpages(void);
28 extern unsigned long totalhigh_pages;
29
30 void kmap_flush_unused(void);
31
32 #else /* CONFIG_HIGHMEM */
33
nr_free_highpages(void)34 static inline unsigned int nr_free_highpages(void) { return 0; }
35
36 #define totalhigh_pages 0
37
38 #ifndef ARCH_HAS_KMAP
kmap(struct page * page)39 static 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
47 #include <asm/kmap_types.h>
48
kmap_atomic(struct page * page,enum km_type idx)49 static inline void *kmap_atomic(struct page *page, enum km_type idx)
50 {
51 pagefault_disable();
52 return page_address(page);
53 }
54 #define kmap_atomic_prot(page, idx, prot) kmap_atomic(page, idx)
55
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)
59
60 #define kmap_flush_unused() do {} while(0)
61 #endif
62
63 #endif /* CONFIG_HIGHMEM */
64
65 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
66 #ifndef clear_user_highpage
clear_user_highpage(struct page * page,unsigned long vaddr)67 static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
68 {
69 void *addr = kmap_atomic(page, KM_USER0);
70 clear_user_page(addr, vaddr, page);
71 kunmap_atomic(addr, KM_USER0);
72 }
73 #endif
74
75 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
76 /**
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 */
90 static inline struct page *
__alloc_zeroed_user_highpage(gfp_t movableflags,struct vm_area_struct * vma,unsigned long vaddr)91 __alloc_zeroed_user_highpage(gfp_t movableflags,
92 struct vm_area_struct *vma,
93 unsigned long vaddr)
94 {
95 struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
96 vma, vaddr);
97
98 if (page)
99 clear_user_highpage(page, vaddr);
100
101 return page;
102 }
103 #endif
104
105 /**
106 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
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 * be able to migrate in the future using move_pages() or reclaimed
112 */
113 static inline struct page *
alloc_zeroed_user_highpage_movable(struct vm_area_struct * vma,unsigned long vaddr)114 alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
115 unsigned long vaddr)
116 {
117 return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
118 }
119
clear_highpage(struct page * page)120 static inline void clear_highpage(struct page *page)
121 {
122 void *kaddr = kmap_atomic(page, KM_USER0);
123 clear_page(kaddr);
124 kunmap_atomic(kaddr, KM_USER0);
125 }
126
zero_user_segments(struct page * page,unsigned start1,unsigned end1,unsigned start2,unsigned end2)127 static inline void zero_user_segments(struct page *page,
128 unsigned start1, unsigned end1,
129 unsigned start2, unsigned end2)
130 {
131 void *kaddr = kmap_atomic(page, KM_USER0);
132
133 BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);
134
135 if (end1 > start1)
136 memset(kaddr + start1, 0, end1 - start1);
137
138 if (end2 > start2)
139 memset(kaddr + start2, 0, end2 - start2);
140
141 kunmap_atomic(kaddr, KM_USER0);
142 flush_dcache_page(page);
143 }
144
zero_user_segment(struct page * page,unsigned start,unsigned end)145 static inline void zero_user_segment(struct page *page,
146 unsigned start, unsigned end)
147 {
148 zero_user_segments(page, start, end, 0, 0);
149 }
150
zero_user(struct page * page,unsigned start,unsigned size)151 static inline void zero_user(struct page *page,
152 unsigned start, unsigned size)
153 {
154 zero_user_segments(page, start, start + size, 0, 0);
155 }
156
memclear_highpage_flush(struct page * page,unsigned int offset,unsigned int size)157 static inline void __deprecated memclear_highpage_flush(struct page *page,
158 unsigned int offset, unsigned int size)
159 {
160 zero_user(page, offset, size);
161 }
162
163 #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
164
copy_user_highpage(struct page * to,struct page * from,unsigned long vaddr,struct vm_area_struct * vma)165 static inline void copy_user_highpage(struct page *to, struct page *from,
166 unsigned long vaddr, struct vm_area_struct *vma)
167 {
168 char *vfrom, *vto;
169
170 vfrom = kmap_atomic(from, KM_USER0);
171 vto = kmap_atomic(to, KM_USER1);
172 copy_user_page(vto, vfrom, vaddr, to);
173 kunmap_atomic(vfrom, KM_USER0);
174 kunmap_atomic(vto, KM_USER1);
175 }
176
177 #endif
178
copy_highpage(struct page * to,struct page * from)179 static inline void copy_highpage(struct page *to, struct page *from)
180 {
181 char *vfrom, *vto;
182
183 vfrom = kmap_atomic(from, KM_USER0);
184 vto = kmap_atomic(to, KM_USER1);
185 copy_page(vto, vfrom);
186 kunmap_atomic(vfrom, KM_USER0);
187 kunmap_atomic(vto, KM_USER1);
188 }
189
190 #endif /* _LINUX_HIGHMEM_H */
191