Line data Source code
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
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
17 : static inline void flush_kernel_dcache_page(struct page *page)
18 : {
19 : }
20 : #endif
21 :
22 : #include <asm/kmap_types.h>
23 :
24 : #if defined(CONFIG_DEBUG_HIGHMEM) && defined(CONFIG_TRACE_IRQFLAGS_SUPPORT)
25 :
26 : void debug_kmap_atomic(enum km_type type);
27 :
28 : #else
29 :
30 : static inline void debug_kmap_atomic(enum km_type type)
31 : {
32 : }
33 :
34 : #endif
35 :
36 : #ifdef CONFIG_HIGHMEM
37 : #include <asm/highmem.h>
38 :
39 : /* declarations for linux/mm/highmem.c */
40 : unsigned int nr_free_highpages(void);
41 : extern unsigned long totalhigh_pages;
42 :
43 : void kmap_flush_unused(void);
44 :
45 : #else /* CONFIG_HIGHMEM */
46 :
47 : static inline unsigned int nr_free_highpages(void) { return 0; }
48 :
49 : #define totalhigh_pages 0UL
50 :
51 : #ifndef ARCH_HAS_KMAP
52 : static inline void *kmap(struct page *page)
53 : {
54 : might_sleep();
55 : return page_address(page);
56 : }
57 :
58 : static inline void kunmap(struct page *page)
59 : {
60 : }
61 :
62 : static inline void *kmap_atomic(struct page *page, enum km_type idx)
63 : {
64 : pagefault_disable();
65 : return page_address(page);
66 : }
67 : #define kmap_atomic_prot(page, idx, prot) kmap_atomic(page, idx)
68 :
69 : #define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0)
70 : #define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx))
71 : #define kmap_atomic_to_page(ptr) virt_to_page(ptr)
72 :
73 : #define kmap_flush_unused() do {} while(0)
74 : #endif
75 :
76 : #endif /* CONFIG_HIGHMEM */
77 :
78 : /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
79 : #ifndef clear_user_highpage
80 : static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
81 : {
82 : void *addr = kmap_atomic(page, KM_USER0);
83 : clear_user_page(addr, vaddr, page);
84 : kunmap_atomic(addr, KM_USER0);
85 : }
86 : #endif
87 :
88 : #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
89 : /**
90 : * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
91 : * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
92 : * @vma: The VMA the page is to be allocated for
93 : * @vaddr: The virtual address the page will be inserted into
94 : *
95 : * This function will allocate a page for a VMA but the caller is expected
96 : * to specify via movableflags whether the page will be movable in the
97 : * future or not
98 : *
99 : * An architecture may override this function by defining
100 : * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
101 : * implementation.
102 : */
103 : static inline struct page *
104 : __alloc_zeroed_user_highpage(gfp_t movableflags,
105 : struct vm_area_struct *vma,
106 : unsigned long vaddr)
107 : {
108 : struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
109 : vma, vaddr);
110 :
111 : if (page)
112 : clear_user_highpage(page, vaddr);
113 :
114 : return page;
115 : }
116 : #endif
117 :
118 : /**
119 : * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
120 : * @vma: The VMA the page is to be allocated for
121 : * @vaddr: The virtual address the page will be inserted into
122 : *
123 : * This function will allocate a page for a VMA that the caller knows will
124 : * be able to migrate in the future using move_pages() or reclaimed
125 : */
126 : static inline struct page *
127 : alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
128 : unsigned long vaddr)
129 : {
130 : return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
131 : }
132 :
133 : static inline void clear_highpage(struct page *page)
134 : {
135 : void *kaddr = kmap_atomic(page, KM_USER0);
136 : clear_page(kaddr);
137 : kunmap_atomic(kaddr, KM_USER0);
138 : }
139 :
140 : static inline void zero_user_segments(struct page *page,
141 : unsigned start1, unsigned end1,
142 : unsigned start2, unsigned end2)
143 : {
144 : void *kaddr = kmap_atomic(page, KM_USER0);
145 :
146 : BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);
147 :
148 : if (end1 > start1)
149 : memset(kaddr + start1, 0, end1 - start1);
150 :
151 : if (end2 > start2)
152 : memset(kaddr + start2, 0, end2 - start2);
153 :
154 : kunmap_atomic(kaddr, KM_USER0);
155 : flush_dcache_page(page);
156 : }
157 :
158 : static inline void zero_user_segment(struct page *page,
159 : unsigned start, unsigned end)
160 : {
161 : zero_user_segments(page, start, end, 0, 0);
162 : }
163 :
164 : static inline void zero_user(struct page *page,
165 : unsigned start, unsigned size)
166 : {
167 : zero_user_segments(page, start, start + size, 0, 0);
168 : }
169 :
170 : static inline void __deprecated memclear_highpage_flush(struct page *page,
171 : unsigned int offset, unsigned int size)
172 : {
173 : zero_user(page, offset, size);
174 : }
175 :
176 : #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
177 :
178 : static inline void copy_user_highpage(struct page *to, struct page *from,
179 : unsigned long vaddr, struct vm_area_struct *vma)
180 : {
181 : char *vfrom, *vto;
182 :
183 : vfrom = kmap_atomic(from, KM_USER0);
184 : vto = kmap_atomic(to, KM_USER1);
185 : copy_user_page(vto, vfrom, vaddr, to);
186 : kunmap_atomic(vfrom, KM_USER0);
187 : kunmap_atomic(vto, KM_USER1);
188 : }
189 :
190 : #endif
191 :
192 : static inline void copy_highpage(struct page *to, struct page *from)
193 : {
194 : char *vfrom, *vto;
195 :
196 : vfrom = kmap_atomic(from, KM_USER0);
197 : vto = kmap_atomic(to, KM_USER1);
198 : copy_page(vto, vfrom);
199 : kunmap_atomic(vfrom, KM_USER0);
200 : kunmap_atomic(vto, KM_USER1);
201 : }
202 1 :
203 : #endif /* _LINUX_HIGHMEM_H */
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