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#ifdef CONFIG_HIGHMEM
23
24#include <asm/highmem.h>
25
26/* declarations for linux/mm/highmem.c */
27unsigned int nr_free_highpages(void);
28extern unsigned long totalhigh_pages;
29
30void kmap_flush_unused(void);
31
32#else /* CONFIG_HIGHMEM */
33
34static inline unsigned int nr_free_highpages(void) { return 0; }
35
36#define totalhigh_pages 0
37
38#ifndef ARCH_HAS_KMAP
39static 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
49static 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 */
66static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
67{
68 void *addr = kmap_atomic(page, KM_USER0);
69 clear_user_page(addr, vaddr, page);
70 kunmap_atomic(addr, KM_USER0);
71 /* Make sure this page is cleared on other CPU's too before using it */
72 smp_wmb();
73}
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 */
90static inline struct page *
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 */
113static inline struct page *
114alloc_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
120static 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
127/*
128 * Same but also flushes aliased cache contents to RAM.
129 *
130 * This must be a macro because KM_USER0 and friends aren't defined if
131 * !CONFIG_HIGHMEM
132 */
133#define zero_user_page(page, offset, size, km_type) \
134 do { \
135 void *kaddr; \
136 \
137 BUG_ON((offset) + (size) > PAGE_SIZE); \
138 \
139 kaddr = kmap_atomic(page, km_type); \
140 memset((char *)kaddr + (offset), 0, (size)); \
141 flush_dcache_page(page); \
142 kunmap_atomic(kaddr, (km_type)); \
143 } while (0)
144
145static inline void __deprecated memclear_highpage_flush(struct page *page,
146 unsigned int offset, unsigned int size)
147{
148 zero_user_page(page, offset, size, KM_USER0);
149}
150
151#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
152
153static inline void copy_user_highpage(struct page *to, struct page *from,
154 unsigned long vaddr, struct vm_area_struct *vma)
155{
156 char *vfrom, *vto;
157
158 vfrom = kmap_atomic(from, KM_USER0);
159 vto = kmap_atomic(to, KM_USER1);
160 copy_user_page(vto, vfrom, vaddr, to);
161 kunmap_atomic(vfrom, KM_USER0);
162 kunmap_atomic(vto, KM_USER1);
163 /* Make sure this page is cleared on other CPU's too before using it */
164 smp_wmb();
165}
166
167#endif
168
169static inline void copy_highpage(struct page *to, struct page *from)
170{
171 char *vfrom, *vto;
172
173 vfrom = kmap_atomic(from, KM_USER0);
174 vto = kmap_atomic(to, KM_USER1);
175 copy_page(vto, vfrom);
176 kunmap_atomic(vfrom, KM_USER0);
177 kunmap_atomic(vto, KM_USER1);
178}
179
180#endif /* _LINUX_HIGHMEM_H */