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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 | |
14 | static 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 | |
20 | static inline void flush_kernel_dcache_page(struct page *page) | |
21 | { | |
22 | } | |
23 | static inline void flush_kernel_vmap_range(void *vaddr, int size) | |
24 | { | |
25 | } | |
26 | static 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 */ | |
37 | unsigned int nr_free_highpages(void); | |
38 | extern unsigned long totalhigh_pages; | |
39 | ||
40 | void kmap_flush_unused(void); | |
41 | ||
42 | struct page *kmap_to_page(void *addr); | |
43 | ||
44 | #else /* CONFIG_HIGHMEM */ | |
45 | ||
46 | static inline unsigned int nr_free_highpages(void) { return 0; } | |
47 | ||
48 | static inline struct page *kmap_to_page(void *addr) | |
49 | { | |
50 | return virt_to_page(addr); | |
51 | } | |
52 | ||
53 | #define totalhigh_pages 0UL | |
54 | ||
55 | #ifndef ARCH_HAS_KMAP | |
56 | static inline void *kmap(struct page *page) | |
57 | { | |
58 | might_sleep(); | |
59 | return page_address(page); | |
60 | } | |
61 | ||
62 | static inline void kunmap(struct page *page) | |
63 | { | |
64 | } | |
65 | ||
66 | static inline void *kmap_atomic(struct page *page) | |
67 | { | |
68 | preempt_disable(); | |
69 | pagefault_disable(); | |
70 | return page_address(page); | |
71 | } | |
72 | #define kmap_atomic_prot(page, prot) kmap_atomic(page) | |
73 | ||
74 | static inline void __kunmap_atomic(void *addr) | |
75 | { | |
76 | pagefault_enable(); | |
77 | preempt_enable(); | |
78 | } | |
79 | ||
80 | #define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn)) | |
81 | ||
82 | #define kmap_flush_unused() do {} while(0) | |
83 | #endif | |
84 | ||
85 | #endif /* CONFIG_HIGHMEM */ | |
86 | ||
87 | #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32) | |
88 | ||
89 | DECLARE_PER_CPU(int, __kmap_atomic_idx); | |
90 | ||
91 | static inline int kmap_atomic_idx_push(void) | |
92 | { | |
93 | int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1; | |
94 | ||
95 | #ifdef CONFIG_DEBUG_HIGHMEM | |
96 | WARN_ON_ONCE(in_irq() && !irqs_disabled()); | |
97 | BUG_ON(idx >= KM_TYPE_NR); | |
98 | #endif | |
99 | return idx; | |
100 | } | |
101 | ||
102 | static inline int kmap_atomic_idx(void) | |
103 | { | |
104 | return __this_cpu_read(__kmap_atomic_idx) - 1; | |
105 | } | |
106 | ||
107 | static inline void kmap_atomic_idx_pop(void) | |
108 | { | |
109 | #ifdef CONFIG_DEBUG_HIGHMEM | |
110 | int idx = __this_cpu_dec_return(__kmap_atomic_idx); | |
111 | ||
112 | BUG_ON(idx < 0); | |
113 | #else | |
114 | __this_cpu_dec(__kmap_atomic_idx); | |
115 | #endif | |
116 | } | |
117 | ||
118 | #endif | |
119 | ||
120 | /* | |
121 | * Prevent people trying to call kunmap_atomic() as if it were kunmap() | |
122 | * kunmap_atomic() should get the return value of kmap_atomic, not the page. | |
123 | */ | |
124 | #define kunmap_atomic(addr) \ | |
125 | do { \ | |
126 | BUILD_BUG_ON(__same_type((addr), struct page *)); \ | |
127 | __kunmap_atomic(addr); \ | |
128 | } while (0) | |
129 | ||
130 | ||
131 | /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ | |
132 | #ifndef clear_user_highpage | |
133 | static inline void clear_user_highpage(struct page *page, unsigned long vaddr) | |
134 | { | |
135 | void *addr = kmap_atomic(page); | |
136 | clear_user_page(addr, vaddr, page); | |
137 | kunmap_atomic(addr); | |
138 | } | |
139 | #endif | |
140 | ||
141 | #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE | |
142 | /** | |
143 | * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags | |
144 | * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE | |
145 | * @vma: The VMA the page is to be allocated for | |
146 | * @vaddr: The virtual address the page will be inserted into | |
147 | * | |
148 | * This function will allocate a page for a VMA but the caller is expected | |
149 | * to specify via movableflags whether the page will be movable in the | |
150 | * future or not | |
151 | * | |
152 | * An architecture may override this function by defining | |
153 | * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own | |
154 | * implementation. | |
155 | */ | |
156 | static inline struct page * | |
157 | __alloc_zeroed_user_highpage(gfp_t movableflags, | |
158 | struct vm_area_struct *vma, | |
159 | unsigned long vaddr) | |
160 | { | |
161 | struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags, | |
162 | vma, vaddr); | |
163 | ||
164 | if (page) | |
165 | clear_user_highpage(page, vaddr); | |
166 | ||
167 | return page; | |
168 | } | |
169 | #endif | |
170 | ||
171 | /** | |
172 | * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move | |
173 | * @vma: The VMA the page is to be allocated for | |
174 | * @vaddr: The virtual address the page will be inserted into | |
175 | * | |
176 | * This function will allocate a page for a VMA that the caller knows will | |
177 | * be able to migrate in the future using move_pages() or reclaimed | |
178 | */ | |
179 | static inline struct page * | |
180 | alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, | |
181 | unsigned long vaddr) | |
182 | { | |
183 | return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr); | |
184 | } | |
185 | ||
186 | static inline void clear_highpage(struct page *page) | |
187 | { | |
188 | void *kaddr = kmap_atomic(page); | |
189 | clear_page(kaddr); | |
190 | kunmap_atomic(kaddr); | |
191 | } | |
192 | ||
193 | static inline void zero_user_segments(struct page *page, | |
194 | unsigned start1, unsigned end1, | |
195 | unsigned start2, unsigned end2) | |
196 | { | |
197 | void *kaddr = kmap_atomic(page); | |
198 | ||
199 | BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE); | |
200 | ||
201 | if (end1 > start1) | |
202 | memset(kaddr + start1, 0, end1 - start1); | |
203 | ||
204 | if (end2 > start2) | |
205 | memset(kaddr + start2, 0, end2 - start2); | |
206 | ||
207 | kunmap_atomic(kaddr); | |
208 | flush_dcache_page(page); | |
209 | } | |
210 | ||
211 | static inline void zero_user_segment(struct page *page, | |
212 | unsigned start, unsigned end) | |
213 | { | |
214 | zero_user_segments(page, start, end, 0, 0); | |
215 | } | |
216 | ||
217 | static inline void zero_user(struct page *page, | |
218 | unsigned start, unsigned size) | |
219 | { | |
220 | zero_user_segments(page, start, start + size, 0, 0); | |
221 | } | |
222 | ||
223 | #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE | |
224 | ||
225 | static inline void copy_user_highpage(struct page *to, struct page *from, | |
226 | unsigned long vaddr, struct vm_area_struct *vma) | |
227 | { | |
228 | char *vfrom, *vto; | |
229 | ||
230 | vfrom = kmap_atomic(from); | |
231 | vto = kmap_atomic(to); | |
232 | copy_user_page(vto, vfrom, vaddr, to); | |
233 | kunmap_atomic(vto); | |
234 | kunmap_atomic(vfrom); | |
235 | } | |
236 | ||
237 | #endif | |
238 | ||
239 | static inline void copy_highpage(struct page *to, struct page *from) | |
240 | { | |
241 | char *vfrom, *vto; | |
242 | ||
243 | vfrom = kmap_atomic(from); | |
244 | vto = kmap_atomic(to); | |
245 | copy_page(vto, vfrom); | |
246 | kunmap_atomic(vto); | |
247 | kunmap_atomic(vfrom); | |
248 | } | |
249 | ||
250 | #endif /* _LINUX_HIGHMEM_H */ |