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