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