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/kernel.h>
6#include <linux/bug.h>
7#include <linux/mm.h>
8#include <linux/uaccess.h>
9#include <linux/hardirq.h>
10
11#include <asm/cacheflush.h>
12
13#ifndef ARCH_HAS_FLUSH_ANON_PAGE
14static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
15{
16}
17#endif
18
19#ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
20static inline void flush_kernel_dcache_page(struct page *page)
21{
22}
23static inline void flush_kernel_vmap_range(void *vaddr, int size)
24{
25}
26static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
27{
28}
29#endif
30
31#include <asm/kmap_types.h>
32
33#ifdef CONFIG_HIGHMEM
34#include <asm/highmem.h>
35
36/* declarations for linux/mm/highmem.c */
37unsigned int nr_free_highpages(void);
38extern unsigned long totalhigh_pages;
39
40void kmap_flush_unused(void);
41
42#else /* CONFIG_HIGHMEM */
43
44static inline unsigned int nr_free_highpages(void) { return 0; }
45
46#define totalhigh_pages 0UL
47
48#ifndef ARCH_HAS_KMAP
49static inline void *kmap(struct page *page)
50{
51 might_sleep();
52 return page_address(page);
53}
54
55static inline void kunmap(struct page *page)
56{
57}
58
59static inline void *kmap_atomic(struct page *page)
60{
61 pagefault_disable();
62 return page_address(page);
63}
64#define kmap_atomic_prot(page, prot) kmap_atomic(page)
65
66static inline void __kunmap_atomic(void *addr)
67{
68 pagefault_enable();
69}
70
71#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
72#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
73
74#define kmap_flush_unused() do {} while(0)
75#endif
76
77#endif /* CONFIG_HIGHMEM */
78
79#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
80
81DECLARE_PER_CPU(int, __kmap_atomic_idx);
82
83static inline int kmap_atomic_idx_push(void)
84{
85 int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
86
87#ifdef CONFIG_DEBUG_HIGHMEM
88 WARN_ON_ONCE(in_irq() && !irqs_disabled());
89 BUG_ON(idx > KM_TYPE_NR);
90#endif
91 return idx;
92}
93
94static inline int kmap_atomic_idx(void)
95{
96 return __this_cpu_read(__kmap_atomic_idx) - 1;
97}
98
99static inline void kmap_atomic_idx_pop(void)
100{
101#ifdef CONFIG_DEBUG_HIGHMEM
102 int idx = __this_cpu_dec_return(__kmap_atomic_idx);
103
104 BUG_ON(idx < 0);
105#else
106 __this_cpu_dec(__kmap_atomic_idx);
107#endif
108}
109
110#endif
111
112/*
113 * NOTE:
114 * kmap_atomic() and kunmap_atomic() with two arguments are deprecated.
115 * We only keep them for backward compatibility, any usage of them
116 * are now warned.
117 */
118
119#define PASTE(a, b) a ## b
120#define PASTE2(a, b) PASTE(a, b)
121
122#define NARG_(_2, _1, n, ...) n
123#define NARG(...) NARG_(__VA_ARGS__, 2, 1, :)
124
125static inline void __deprecated *kmap_atomic_deprecated(struct page *page,
126 enum km_type km)
127{
128 return kmap_atomic(page);
129}
130
131#define kmap_atomic1(...) kmap_atomic(__VA_ARGS__)
132#define kmap_atomic2(...) kmap_atomic_deprecated(__VA_ARGS__)
133#define kmap_atomic(...) PASTE2(kmap_atomic, NARG(__VA_ARGS__)(__VA_ARGS__))
134
135static inline void __deprecated __kunmap_atomic_deprecated(void *addr,
136 enum km_type km)
137{
138 __kunmap_atomic(addr);
139}
140
141/*
142 * Prevent people trying to call kunmap_atomic() as if it were kunmap()
143 * kunmap_atomic() should get the return value of kmap_atomic, not the page.
144 */
145#define kunmap_atomic_deprecated(addr, km) \
146do { \
147 BUILD_BUG_ON(__same_type((addr), struct page *)); \
148 __kunmap_atomic_deprecated(addr, km); \
149} while (0)
150
151#define kunmap_atomic_withcheck(addr) \
152do { \
153 BUILD_BUG_ON(__same_type((addr), struct page *)); \
154 __kunmap_atomic(addr); \
155} while (0)
156
157#define kunmap_atomic1(...) kunmap_atomic_withcheck(__VA_ARGS__)
158#define kunmap_atomic2(...) kunmap_atomic_deprecated(__VA_ARGS__)
159#define kunmap_atomic(...) PASTE2(kunmap_atomic, NARG(__VA_ARGS__)(__VA_ARGS__))
160/**** End of C pre-processor tricks for deprecated macros ****/
161
162/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
163#ifndef clear_user_highpage
164static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
165{
166 void *addr = kmap_atomic(page);
167 clear_user_page(addr, vaddr, page);
168 kunmap_atomic(addr);
169}
170#endif
171
172#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
173/**
174 * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
175 * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
176 * @vma: The VMA the page is to be allocated for
177 * @vaddr: The virtual address the page will be inserted into
178 *
179 * This function will allocate a page for a VMA but the caller is expected
180 * to specify via movableflags whether the page will be movable in the
181 * future or not
182 *
183 * An architecture may override this function by defining
184 * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
185 * implementation.
186 */
187static inline struct page *
188__alloc_zeroed_user_highpage(gfp_t movableflags,
189 struct vm_area_struct *vma,
190 unsigned long vaddr)
191{
192 struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
193 vma, vaddr);
194
195 if (page)
196 clear_user_highpage(page, vaddr);
197
198 return page;
199}
200#endif
201
202/**
203 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
204 * @vma: The VMA the page is to be allocated for
205 * @vaddr: The virtual address the page will be inserted into
206 *
207 * This function will allocate a page for a VMA that the caller knows will
208 * be able to migrate in the future using move_pages() or reclaimed
209 */
210static inline struct page *
211alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
212 unsigned long vaddr)
213{
214 return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
215}
216
217static inline void clear_highpage(struct page *page)
218{
219 void *kaddr = kmap_atomic(page);
220 clear_page(kaddr);
221 kunmap_atomic(kaddr);
222}
223
224static inline void zero_user_segments(struct page *page,
225 unsigned start1, unsigned end1,
226 unsigned start2, unsigned end2)
227{
228 void *kaddr = kmap_atomic(page);
229
230 BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);
231
232 if (end1 > start1)
233 memset(kaddr + start1, 0, end1 - start1);
234
235 if (end2 > start2)
236 memset(kaddr + start2, 0, end2 - start2);
237
238 kunmap_atomic(kaddr);
239 flush_dcache_page(page);
240}
241
242static inline void zero_user_segment(struct page *page,
243 unsigned start, unsigned end)
244{
245 zero_user_segments(page, start, end, 0, 0);
246}
247
248static inline void zero_user(struct page *page,
249 unsigned start, unsigned size)
250{
251 zero_user_segments(page, start, start + size, 0, 0);
252}
253
254static inline void __deprecated memclear_highpage_flush(struct page *page,
255 unsigned int offset, unsigned int size)
256{
257 zero_user(page, offset, size);
258}
259
260#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
261
262static inline void copy_user_highpage(struct page *to, struct page *from,
263 unsigned long vaddr, struct vm_area_struct *vma)
264{
265 char *vfrom, *vto;
266
267 vfrom = kmap_atomic(from);
268 vto = kmap_atomic(to);
269 copy_user_page(vto, vfrom, vaddr, to);
270 kunmap_atomic(vto);
271 kunmap_atomic(vfrom);
272}
273
274#endif
275
276static inline void copy_highpage(struct page *to, struct page *from)
277{
278 char *vfrom, *vto;
279
280 vfrom = kmap_atomic(from);
281 vto = kmap_atomic(to);
282 copy_page(vto, vfrom);
283 kunmap_atomic(vto);
284 kunmap_atomic(vfrom);
285}
286
287#endif /* _LINUX_HIGHMEM_H */