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}
20static inline void flush_kernel_vmap_range(void *vaddr, int size)
21{
22}
23static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
24{
25}
26#endif
27
28#include <asm/kmap_types.h>
29
30#if defined(CONFIG_DEBUG_HIGHMEM) && defined(CONFIG_TRACE_IRQFLAGS_SUPPORT)
31
32void debug_kmap_atomic(enum km_type type);
33
34#else
35
36static inline void debug_kmap_atomic(enum km_type type)
37{
38}
39
40#endif
41
42#ifdef CONFIG_HIGHMEM
43#include <asm/highmem.h>
44
45/* declarations for linux/mm/highmem.c */
46unsigned int nr_free_highpages(void);
47extern unsigned long totalhigh_pages;
48
49void kmap_flush_unused(void);
50
51#else /* CONFIG_HIGHMEM */
52
53static inline unsigned int nr_free_highpages(void) { return 0; }
54
55#define totalhigh_pages 0UL
56
57#ifndef ARCH_HAS_KMAP
58static inline void *kmap(struct page *page)
59{
60 might_sleep();
61 return page_address(page);
62}
63
64static inline void kunmap(struct page *page)
65{
66}
67
68static inline void *kmap_atomic(struct page *page, enum km_type idx)
69{
70 pagefault_disable();
71 return page_address(page);
72}
73#define kmap_atomic_prot(page, idx, prot) kmap_atomic(page, idx)
74
75#define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0)
76#define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx))
77#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
78
79#define kmap_flush_unused() do {} while(0)
80#endif
81
82#endif /* CONFIG_HIGHMEM */
83
84/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
85#ifndef clear_user_highpage
86static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
87{
88 void *addr = kmap_atomic(page, KM_USER0);
89 clear_user_page(addr, vaddr, page);
90 kunmap_atomic(addr, KM_USER0);
91}
92#endif
93
94#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
95/**
96 * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
97 * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
98 * @vma: The VMA the page is to be allocated for
99 * @vaddr: The virtual address the page will be inserted into
100 *
101 * This function will allocate a page for a VMA but the caller is expected
102 * to specify via movableflags whether the page will be movable in the
103 * future or not
104 *
105 * An architecture may override this function by defining
106 * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
107 * implementation.
108 */
109static inline struct page *
110__alloc_zeroed_user_highpage(gfp_t movableflags,
111 struct vm_area_struct *vma,
112 unsigned long vaddr)
113{
114 struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
115 vma, vaddr);
116
117 if (page)
118 clear_user_highpage(page, vaddr);
119
120 return page;
121}
122#endif
123
124/**
125 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
126 * @vma: The VMA the page is to be allocated for
127 * @vaddr: The virtual address the page will be inserted into
128 *
129 * This function will allocate a page for a VMA that the caller knows will
130 * be able to migrate in the future using move_pages() or reclaimed
131 */
132static inline struct page *
133alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
134 unsigned long vaddr)
135{
136 return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
137}
138
139static inline void clear_highpage(struct page *page)
140{
141 void *kaddr = kmap_atomic(page, KM_USER0);
142 clear_page(kaddr);
143 kunmap_atomic(kaddr, KM_USER0);
144}
145
146static inline void zero_user_segments(struct page *page,
147 unsigned start1, unsigned end1,
148 unsigned start2, unsigned end2)
149{
150 void *kaddr = kmap_atomic(page, KM_USER0);
151
152 BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);
153
154 if (end1 > start1)
155 memset(kaddr + start1, 0, end1 - start1);
156
157 if (end2 > start2)
158 memset(kaddr + start2, 0, end2 - start2);
159
160 kunmap_atomic(kaddr, KM_USER0);
161 flush_dcache_page(page);
162}
163
164static inline void zero_user_segment(struct page *page,
165 unsigned start, unsigned end)
166{
167 zero_user_segments(page, start, end, 0, 0);
168}
169
170static inline void zero_user(struct page *page,
171 unsigned start, unsigned size)
172{
173 zero_user_segments(page, start, start + size, 0, 0);
174}
175
176static inline void __deprecated memclear_highpage_flush(struct page *page,
177 unsigned int offset, unsigned int size)
178{
179 zero_user(page, offset, size);
180}
181
182#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
183
184static inline void copy_user_highpage(struct page *to, struct page *from,
185 unsigned long vaddr, struct vm_area_struct *vma)
186{
187 char *vfrom, *vto;
188
189 vfrom = kmap_atomic(from, KM_USER0);
190 vto = kmap_atomic(to, KM_USER1);
191 copy_user_page(vto, vfrom, vaddr, to);
192 kunmap_atomic(vfrom, KM_USER0);
193 kunmap_atomic(vto, KM_USER1);
194}
195
196#endif
197
198static inline void copy_highpage(struct page *to, struct page *from)
199{
200 char *vfrom, *vto;
201
202 vfrom = kmap_atomic(from, KM_USER0);
203 vto = kmap_atomic(to, KM_USER1);
204 copy_page(vto, vfrom);
205 kunmap_atomic(vfrom, KM_USER0);
206 kunmap_atomic(vto, KM_USER1);
207}
208
209#endif /* _LINUX_HIGHMEM_H */