embedded: fix vc_translate operator precedence
[linux-2.6] / include / asm-avr32 / uaccess.h
1 /*
2  * Copyright (C) 2004-2006 Atmel Corporation
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 #ifndef __ASM_AVR32_UACCESS_H
9 #define __ASM_AVR32_UACCESS_H
10
11 #include <linux/errno.h>
12 #include <linux/sched.h>
13
14 #define VERIFY_READ     0
15 #define VERIFY_WRITE    1
16
17 typedef struct {
18         unsigned int is_user_space;
19 } mm_segment_t;
20
21 /*
22  * The fs value determines whether argument validity checking should be
23  * performed or not.  If get_fs() == USER_DS, checking is performed, with
24  * get_fs() == KERNEL_DS, checking is bypassed.
25  *
26  * For historical reasons (Data Segment Register?), these macros are misnamed.
27  */
28 #define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })
29 #define segment_eq(a,b) ((a).is_user_space == (b).is_user_space)
30
31 #define USER_ADDR_LIMIT 0x80000000
32
33 #define KERNEL_DS       MAKE_MM_SEG(0)
34 #define USER_DS         MAKE_MM_SEG(1)
35
36 #define get_ds()        (KERNEL_DS)
37
38 static inline mm_segment_t get_fs(void)
39 {
40         return MAKE_MM_SEG(test_thread_flag(TIF_USERSPACE));
41 }
42
43 static inline void set_fs(mm_segment_t s)
44 {
45         if (s.is_user_space)
46                 set_thread_flag(TIF_USERSPACE);
47         else
48                 clear_thread_flag(TIF_USERSPACE);
49 }
50
51 /*
52  * Test whether a block of memory is a valid user space address.
53  * Returns 0 if the range is valid, nonzero otherwise.
54  *
55  * We do the following checks:
56  *   1. Is the access from kernel space?
57  *   2. Does (addr + size) set the carry bit?
58  *   3. Is (addr + size) a negative number (i.e. >= 0x80000000)?
59  *
60  * If yes on the first check, access is granted.
61  * If no on any of the others, access is denied.
62  */
63 #define __range_ok(addr, size)                                          \
64         (test_thread_flag(TIF_USERSPACE)                                \
65          && (((unsigned long)(addr) >= 0x80000000)                      \
66              || ((unsigned long)(size) > 0x80000000)                    \
67              || (((unsigned long)(addr) + (unsigned long)(size)) > 0x80000000)))
68
69 #define access_ok(type, addr, size) (likely(__range_ok(addr, size) == 0))
70
71 /* Generic arbitrary sized copy. Return the number of bytes NOT copied */
72 extern __kernel_size_t __copy_user(void *to, const void *from,
73                                    __kernel_size_t n);
74
75 extern __kernel_size_t copy_to_user(void __user *to, const void *from,
76                                     __kernel_size_t n);
77 extern __kernel_size_t copy_from_user(void *to, const void __user *from,
78                                       __kernel_size_t n);
79
80 static inline __kernel_size_t __copy_to_user(void __user *to, const void *from,
81                                              __kernel_size_t n)
82 {
83         return __copy_user((void __force *)to, from, n);
84 }
85 static inline __kernel_size_t __copy_from_user(void *to,
86                                                const void __user *from,
87                                                __kernel_size_t n)
88 {
89         return __copy_user(to, (const void __force *)from, n);
90 }
91
92 #define __copy_to_user_inatomic __copy_to_user
93 #define __copy_from_user_inatomic __copy_from_user
94
95 /*
96  * put_user: - Write a simple value into user space.
97  * @x:   Value to copy to user space.
98  * @ptr: Destination address, in user space.
99  *
100  * Context: User context only.  This function may sleep.
101  *
102  * This macro copies a single simple value from kernel space to user
103  * space.  It supports simple types like char and int, but not larger
104  * data types like structures or arrays.
105  *
106  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
107  * to the result of dereferencing @ptr.
108  *
109  * Returns zero on success, or -EFAULT on error.
110  */
111 #define put_user(x,ptr) \
112         __put_user_check((x),(ptr),sizeof(*(ptr)))
113
114 /*
115  * get_user: - Get a simple variable from user space.
116  * @x:   Variable to store result.
117  * @ptr: Source address, in user space.
118  *
119  * Context: User context only.  This function may sleep.
120  *
121  * This macro copies a single simple variable from user space to kernel
122  * space.  It supports simple types like char and int, but not larger
123  * data types like structures or arrays.
124  *
125  * @ptr must have pointer-to-simple-variable type, and the result of
126  * dereferencing @ptr must be assignable to @x without a cast.
127  *
128  * Returns zero on success, or -EFAULT on error.
129  * On error, the variable @x is set to zero.
130  */
131 #define get_user(x,ptr) \
132         __get_user_check((x),(ptr),sizeof(*(ptr)))
133
134 /*
135  * __put_user: - Write a simple value into user space, with less checking.
136  * @x:   Value to copy to user space.
137  * @ptr: Destination address, in user space.
138  *
139  * Context: User context only.  This function may sleep.
140  *
141  * This macro copies a single simple value from kernel space to user
142  * space.  It supports simple types like char and int, but not larger
143  * data types like structures or arrays.
144  *
145  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
146  * to the result of dereferencing @ptr.
147  *
148  * Caller must check the pointer with access_ok() before calling this
149  * function.
150  *
151  * Returns zero on success, or -EFAULT on error.
152  */
153 #define __put_user(x,ptr) \
154         __put_user_nocheck((x),(ptr),sizeof(*(ptr)))
155
156 /*
157  * __get_user: - Get a simple variable from user space, with less checking.
158  * @x:   Variable to store result.
159  * @ptr: Source address, in user space.
160  *
161  * Context: User context only.  This function may sleep.
162  *
163  * This macro copies a single simple variable from user space to kernel
164  * space.  It supports simple types like char and int, but not larger
165  * data types like structures or arrays.
166  *
167  * @ptr must have pointer-to-simple-variable type, and the result of
168  * dereferencing @ptr must be assignable to @x without a cast.
169  *
170  * Caller must check the pointer with access_ok() before calling this
171  * function.
172  *
173  * Returns zero on success, or -EFAULT on error.
174  * On error, the variable @x is set to zero.
175  */
176 #define __get_user(x,ptr) \
177         __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
178
179 extern int __get_user_bad(void);
180 extern int __put_user_bad(void);
181
182 #define __get_user_nocheck(x, ptr, size)                                \
183 ({                                                                      \
184         unsigned long __gu_val = 0;                                     \
185         int __gu_err = 0;                                               \
186                                                                         \
187         switch (size) {                                                 \
188         case 1: __get_user_asm("ub", __gu_val, ptr, __gu_err); break;   \
189         case 2: __get_user_asm("uh", __gu_val, ptr, __gu_err); break;   \
190         case 4: __get_user_asm("w", __gu_val, ptr, __gu_err); break;    \
191         default: __gu_err = __get_user_bad(); break;                    \
192         }                                                               \
193                                                                         \
194         x = (typeof(*(ptr)))__gu_val;                                   \
195         __gu_err;                                                       \
196 })
197
198 #define __get_user_check(x, ptr, size)                                  \
199 ({                                                                      \
200         unsigned long __gu_val = 0;                                     \
201         const typeof(*(ptr)) __user * __gu_addr = (ptr);                \
202         int __gu_err = 0;                                               \
203                                                                         \
204         if (access_ok(VERIFY_READ, __gu_addr, size)) {                  \
205                 switch (size) {                                         \
206                 case 1:                                                 \
207                         __get_user_asm("ub", __gu_val, __gu_addr,       \
208                                        __gu_err);                       \
209                         break;                                          \
210                 case 2:                                                 \
211                         __get_user_asm("uh", __gu_val, __gu_addr,       \
212                                        __gu_err);                       \
213                         break;                                          \
214                 case 4:                                                 \
215                         __get_user_asm("w", __gu_val, __gu_addr,        \
216                                        __gu_err);                       \
217                         break;                                          \
218                 default:                                                \
219                         __gu_err = __get_user_bad();                    \
220                         break;                                          \
221                 }                                                       \
222         } else {                                                        \
223                 __gu_err = -EFAULT;                                     \
224         }                                                               \
225         x = (typeof(*(ptr)))__gu_val;                                   \
226         __gu_err;                                                       \
227 })
228
229 #define __get_user_asm(suffix, __gu_val, ptr, __gu_err)                 \
230         asm volatile(                                                   \
231                 "1:     ld." suffix "   %1, %3                  \n"     \
232                 "2:                                             \n"     \
233                 "       .section .fixup, \"ax\"                 \n"     \
234                 "3:     mov     %0, %4                          \n"     \
235                 "       rjmp    2b                              \n"     \
236                 "       .previous                               \n"     \
237                 "       .section __ex_table, \"a\"              \n"     \
238                 "       .long   1b, 3b                          \n"     \
239                 "       .previous                               \n"     \
240                 : "=r"(__gu_err), "=r"(__gu_val)                        \
241                 : "0"(__gu_err), "m"(*(ptr)), "i"(-EFAULT))
242
243 #define __put_user_nocheck(x, ptr, size)                                \
244 ({                                                                      \
245         typeof(*(ptr)) __pu_val;                                        \
246         int __pu_err = 0;                                               \
247                                                                         \
248         __pu_val = (x);                                                 \
249         switch (size) {                                                 \
250         case 1: __put_user_asm("b", ptr, __pu_val, __pu_err); break;    \
251         case 2: __put_user_asm("h", ptr, __pu_val, __pu_err); break;    \
252         case 4: __put_user_asm("w", ptr, __pu_val, __pu_err); break;    \
253         case 8: __put_user_asm("d", ptr, __pu_val, __pu_err); break;    \
254         default: __pu_err = __put_user_bad(); break;                    \
255         }                                                               \
256         __pu_err;                                                       \
257 })
258
259 #define __put_user_check(x, ptr, size)                                  \
260 ({                                                                      \
261         typeof(*(ptr)) __pu_val;                                        \
262         typeof(*(ptr)) __user *__pu_addr = (ptr);                       \
263         int __pu_err = 0;                                               \
264                                                                         \
265         __pu_val = (x);                                                 \
266         if (access_ok(VERIFY_WRITE, __pu_addr, size)) {                 \
267                 switch (size) {                                         \
268                 case 1:                                                 \
269                         __put_user_asm("b", __pu_addr, __pu_val,        \
270                                        __pu_err);                       \
271                         break;                                          \
272                 case 2:                                                 \
273                         __put_user_asm("h", __pu_addr, __pu_val,        \
274                                        __pu_err);                       \
275                         break;                                          \
276                 case 4:                                                 \
277                         __put_user_asm("w", __pu_addr, __pu_val,        \
278                                        __pu_err);                       \
279                         break;                                          \
280                 case 8:                                                 \
281                         __put_user_asm("d", __pu_addr, __pu_val,                \
282                                        __pu_err);                       \
283                         break;                                          \
284                 default:                                                \
285                         __pu_err = __put_user_bad();                    \
286                         break;                                          \
287                 }                                                       \
288         } else {                                                        \
289                 __pu_err = -EFAULT;                                     \
290         }                                                               \
291         __pu_err;                                                       \
292 })
293
294 #define __put_user_asm(suffix, ptr, __pu_val, __gu_err)                 \
295         asm volatile(                                                   \
296                 "1:     st." suffix "   %1, %3                  \n"     \
297                 "2:                                             \n"     \
298                 "       .section .fixup, \"ax\"                 \n"     \
299                 "3:     mov     %0, %4                          \n"     \
300                 "       rjmp    2b                              \n"     \
301                 "       .previous                               \n"     \
302                 "       .section __ex_table, \"a\"              \n"     \
303                 "       .long   1b, 3b                          \n"     \
304                 "       .previous                               \n"     \
305                 : "=r"(__gu_err), "=m"(*(ptr))                          \
306                 : "0"(__gu_err), "r"(__pu_val), "i"(-EFAULT))
307
308 extern __kernel_size_t clear_user(void __user *addr, __kernel_size_t size);
309 extern __kernel_size_t __clear_user(void __user *addr, __kernel_size_t size);
310
311 extern long strncpy_from_user(char *dst, const char __user *src, long count);
312 extern long __strncpy_from_user(char *dst, const char __user *src, long count);
313
314 extern long strnlen_user(const char __user *__s, long __n);
315 extern long __strnlen_user(const char __user *__s, long __n);
316
317 #define strlen_user(s) strnlen_user(s, ~0UL >> 1)
318
319 struct exception_table_entry
320 {
321         unsigned long insn, fixup;
322 };
323
324 #endif /* __ASM_AVR32_UACCESS_H */