media: video: tegra: ov5650: read sensor fuse id
[linux-2.6.git] / include / asm-generic / uaccess.h
1 #ifndef __ASM_GENERIC_UACCESS_H
2 #define __ASM_GENERIC_UACCESS_H
3
4 /*
5  * User space memory access functions, these should work
6  * on a ny machine that has kernel and user data in the same
7  * address space, e.g. all NOMMU machines.
8  */
9 #include <linux/sched.h>
10 #include <linux/mm.h>
11 #include <linux/string.h>
12
13 #include <asm/segment.h>
14
15 #define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })
16
17 #ifndef KERNEL_DS
18 #define KERNEL_DS       MAKE_MM_SEG(~0UL)
19 #endif
20
21 #ifndef USER_DS
22 #define USER_DS         MAKE_MM_SEG(TASK_SIZE - 1)
23 #endif
24
25 #ifndef get_fs
26 #define get_ds()        (KERNEL_DS)
27 #define get_fs()        (current_thread_info()->addr_limit)
28
29 static inline void set_fs(mm_segment_t fs)
30 {
31         current_thread_info()->addr_limit = fs;
32 }
33 #endif
34
35 #define segment_eq(a, b) ((a).seg == (b).seg)
36
37 #define VERIFY_READ     0
38 #define VERIFY_WRITE    1
39
40 #define access_ok(type, addr, size) __access_ok((unsigned long)(addr),(size))
41
42 /*
43  * The architecture should really override this if possible, at least
44  * doing a check on the get_fs()
45  */
46 #ifndef __access_ok
47 static inline int __access_ok(unsigned long addr, unsigned long size)
48 {
49         return 1;
50 }
51 #endif
52
53 /*
54  * The exception table consists of pairs of addresses: the first is the
55  * address of an instruction that is allowed to fault, and the second is
56  * the address at which the program should continue.  No registers are
57  * modified, so it is entirely up to the continuation code to figure out
58  * what to do.
59  *
60  * All the routines below use bits of fixup code that are out of line
61  * with the main instruction path.  This means when everything is well,
62  * we don't even have to jump over them.  Further, they do not intrude
63  * on our cache or tlb entries.
64  */
65
66 struct exception_table_entry
67 {
68         unsigned long insn, fixup;
69 };
70
71 /* Returns 0 if exception not found and fixup otherwise.  */
72 extern unsigned long search_exception_table(unsigned long);
73
74 /*
75  * architectures with an MMU should override these two
76  */
77 #ifndef __copy_from_user
78 static inline __must_check long __copy_from_user(void *to,
79                 const void __user * from, unsigned long n)
80 {
81         if (__builtin_constant_p(n)) {
82                 switch(n) {
83                 case 1:
84                         *(u8 *)to = *(u8 __force *)from;
85                         return 0;
86                 case 2:
87                         *(u16 *)to = *(u16 __force *)from;
88                         return 0;
89                 case 4:
90                         *(u32 *)to = *(u32 __force *)from;
91                         return 0;
92 #ifdef CONFIG_64BIT
93                 case 8:
94                         *(u64 *)to = *(u64 __force *)from;
95                         return 0;
96 #endif
97                 default:
98                         break;
99                 }
100         }
101
102         memcpy(to, (const void __force *)from, n);
103         return 0;
104 }
105 #endif
106
107 #ifndef __copy_to_user
108 static inline __must_check long __copy_to_user(void __user *to,
109                 const void *from, unsigned long n)
110 {
111         if (__builtin_constant_p(n)) {
112                 switch(n) {
113                 case 1:
114                         *(u8 __force *)to = *(u8 *)from;
115                         return 0;
116                 case 2:
117                         *(u16 __force *)to = *(u16 *)from;
118                         return 0;
119                 case 4:
120                         *(u32 __force *)to = *(u32 *)from;
121                         return 0;
122 #ifdef CONFIG_64BIT
123                 case 8:
124                         *(u64 __force *)to = *(u64 *)from;
125                         return 0;
126 #endif
127                 default:
128                         break;
129                 }
130         }
131
132         memcpy((void __force *)to, from, n);
133         return 0;
134 }
135 #endif
136
137 /*
138  * These are the main single-value transfer routines.  They automatically
139  * use the right size if we just have the right pointer type.
140  * This version just falls back to copy_{from,to}_user, which should
141  * provide a fast-path for small values.
142  */
143 #define __put_user(x, ptr) \
144 ({                                                              \
145         __typeof__(*(ptr)) __x = (x);                           \
146         int __pu_err = -EFAULT;                                 \
147         __chk_user_ptr(ptr);                                    \
148         switch (sizeof (*(ptr))) {                              \
149         case 1:                                                 \
150         case 2:                                                 \
151         case 4:                                                 \
152         case 8:                                                 \
153                 __pu_err = __put_user_fn(sizeof (*(ptr)),       \
154                                          ptr, &__x);            \
155                 break;                                          \
156         default:                                                \
157                 __put_user_bad();                               \
158                 break;                                          \
159          }                                                      \
160         __pu_err;                                               \
161 })
162
163 #define put_user(x, ptr)                                        \
164 ({                                                              \
165         might_sleep();                                          \
166         access_ok(VERIFY_WRITE, ptr, sizeof(*ptr)) ?            \
167                 __put_user(x, ptr) :                            \
168                 -EFAULT;                                        \
169 })
170
171 static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
172 {
173         size = __copy_to_user(ptr, x, size);
174         return size ? -EFAULT : size;
175 }
176
177 extern int __put_user_bad(void) __attribute__((noreturn));
178
179 #define __get_user(x, ptr)                                      \
180 ({                                                              \
181         int __gu_err = -EFAULT;                                 \
182         __chk_user_ptr(ptr);                                    \
183         switch (sizeof(*(ptr))) {                               \
184         case 1: {                                               \
185                 unsigned char __x;                              \
186                 __gu_err = __get_user_fn(sizeof (*(ptr)),       \
187                                          ptr, &__x);            \
188                 (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
189                 break;                                          \
190         };                                                      \
191         case 2: {                                               \
192                 unsigned short __x;                             \
193                 __gu_err = __get_user_fn(sizeof (*(ptr)),       \
194                                          ptr, &__x);            \
195                 (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
196                 break;                                          \
197         };                                                      \
198         case 4: {                                               \
199                 unsigned int __x;                               \
200                 __gu_err = __get_user_fn(sizeof (*(ptr)),       \
201                                          ptr, &__x);            \
202                 (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
203                 break;                                          \
204         };                                                      \
205         case 8: {                                               \
206                 unsigned long long __x;                         \
207                 __gu_err = __get_user_fn(sizeof (*(ptr)),       \
208                                          ptr, &__x);            \
209                 (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
210                 break;                                          \
211         };                                                      \
212         default:                                                \
213                 __get_user_bad();                               \
214                 break;                                          \
215         }                                                       \
216         __gu_err;                                               \
217 })
218
219 #define get_user(x, ptr)                                        \
220 ({                                                              \
221         might_sleep();                                          \
222         access_ok(VERIFY_READ, ptr, sizeof(*ptr)) ?             \
223                 __get_user(x, ptr) :                            \
224                 -EFAULT;                                        \
225 })
226
227 static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
228 {
229         size = __copy_from_user(x, ptr, size);
230         return size ? -EFAULT : size;
231 }
232
233 extern int __get_user_bad(void) __attribute__((noreturn));
234
235 #ifndef __copy_from_user_inatomic
236 #define __copy_from_user_inatomic __copy_from_user
237 #endif
238
239 #ifndef __copy_to_user_inatomic
240 #define __copy_to_user_inatomic __copy_to_user
241 #endif
242
243 static inline long copy_from_user(void *to,
244                 const void __user * from, unsigned long n)
245 {
246         might_sleep();
247         if (access_ok(VERIFY_READ, from, n))
248                 return __copy_from_user(to, from, n);
249         else
250                 return n;
251 }
252
253 static inline long copy_to_user(void __user *to,
254                 const void *from, unsigned long n)
255 {
256         might_sleep();
257         if (access_ok(VERIFY_WRITE, to, n))
258                 return __copy_to_user(to, from, n);
259         else
260                 return n;
261 }
262
263 /*
264  * Copy a null terminated string from userspace.
265  */
266 #ifndef __strncpy_from_user
267 static inline long
268 __strncpy_from_user(char *dst, const char __user *src, long count)
269 {
270         char *tmp;
271         strncpy(dst, (const char __force *)src, count);
272         for (tmp = dst; *tmp && count > 0; tmp++, count--)
273                 ;
274         return (tmp - dst);
275 }
276 #endif
277
278 static inline long
279 strncpy_from_user(char *dst, const char __user *src, long count)
280 {
281         if (!access_ok(VERIFY_READ, src, 1))
282                 return -EFAULT;
283         return __strncpy_from_user(dst, src, count);
284 }
285
286 /*
287  * Return the size of a string (including the ending 0)
288  *
289  * Return 0 on exception, a value greater than N if too long
290  */
291 #ifndef __strnlen_user
292 #define __strnlen_user(s, n) (strnlen((s), (n)) + 1)
293 #endif
294
295 /*
296  * Unlike strnlen, strnlen_user includes the nul terminator in
297  * its returned count. Callers should check for a returned value
298  * greater than N as an indication the string is too long.
299  */
300 static inline long strnlen_user(const char __user *src, long n)
301 {
302         if (!access_ok(VERIFY_READ, src, 1))
303                 return 0;
304         return __strnlen_user(src, n);
305 }
306
307 static inline long strlen_user(const char __user *src)
308 {
309         return strnlen_user(src, 32767);
310 }
311
312 /*
313  * Zero Userspace
314  */
315 #ifndef __clear_user
316 static inline __must_check unsigned long
317 __clear_user(void __user *to, unsigned long n)
318 {
319         memset((void __force *)to, 0, n);
320         return 0;
321 }
322 #endif
323
324 static inline __must_check unsigned long
325 clear_user(void __user *to, unsigned long n)
326 {
327         might_sleep();
328         if (!access_ok(VERIFY_WRITE, to, n))
329                 return n;
330
331         return __clear_user(to, n);
332 }
333
334 #endif /* __ASM_GENERIC_UACCESS_H */