Linux kernel mirror (for testing)
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linux
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
11static 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
17static 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
26void debug_kmap_atomic(enum km_type type);
27
28#else
29
30static 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 */
40unsigned int nr_free_highpages(void);
41extern unsigned long totalhigh_pages;
42
43void kmap_flush_unused(void);
44
45#else /* CONFIG_HIGHMEM */
46
47static inline unsigned int nr_free_highpages(void) { return 0; }
48
49#define totalhigh_pages 0UL
50
51#ifndef ARCH_HAS_KMAP
52static inline void *kmap(struct page *page)
53{
54 might_sleep();
55 return page_address(page);
56}
57
58static inline void kunmap(struct page *page)
59{
60}
61
62static 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
80static 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 */
103static 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 */
126static inline struct page *
127alloc_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
133static 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
140static 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
158static 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
164static 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
170static 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
178static 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
192static 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
203#endif /* _LINUX_HIGHMEM_H */