[PATCH] blktrace: readahead support
[linux-2.6] / include / asm-sh64 / uaccess.h
1 #ifndef __ASM_SH64_UACCESS_H
2 #define __ASM_SH64_UACCESS_H
3
4 /*
5  * This file is subject to the terms and conditions of the GNU General Public
6  * License.  See the file "COPYING" in the main directory of this archive
7  * for more details.
8  *
9  * include/asm-sh64/uaccess.h
10  *
11  * Copyright (C) 2000, 2001  Paolo Alberelli
12  * Copyright (C) 2003, 2004  Paul Mundt
13  *
14  * User space memory access functions
15  *
16  * Copyright (C) 1999  Niibe Yutaka
17  *
18  *  Based on:
19  *     MIPS implementation version 1.15 by
20  *              Copyright (C) 1996, 1997, 1998 by Ralf Baechle
21  *     and i386 version.
22  *
23  */
24
25 #include <linux/errno.h>
26 #include <linux/sched.h>
27
28 #define VERIFY_READ    0
29 #define VERIFY_WRITE   1
30
31 /*
32  * The fs value determines whether argument validity checking should be
33  * performed or not.  If get_fs() == USER_DS, checking is performed, with
34  * get_fs() == KERNEL_DS, checking is bypassed.
35  *
36  * For historical reasons (Data Segment Register?), these macros are misnamed.
37  */
38
39 #define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })
40
41 #define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFF)
42 #define USER_DS         MAKE_MM_SEG(0x80000000)
43
44 #define get_ds()        (KERNEL_DS)
45 #define get_fs()        (current_thread_info()->addr_limit)
46 #define set_fs(x)       (current_thread_info()->addr_limit=(x))
47
48 #define segment_eq(a,b) ((a).seg == (b).seg)
49
50 #define __addr_ok(addr) ((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
51
52 /*
53  * Uhhuh, this needs 33-bit arithmetic. We have a carry..
54  *
55  * sum := addr + size;  carry? --> flag = true;
56  * if (sum >= addr_limit) flag = true;
57  */
58 #define __range_ok(addr,size) (((unsigned long) (addr) + (size) < (current_thread_info()->addr_limit.seg)) ? 0 : 1)
59
60 #define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
61 #define __access_ok(addr,size) (__range_ok(addr,size) == 0)
62
63 /*
64  * Uh, these should become the main single-value transfer routines ...
65  * They automatically use the right size if we just have the right
66  * pointer type ...
67  *
68  * As MIPS uses the same address space for kernel and user data, we
69  * can just do these as direct assignments.
70  *
71  * Careful to not
72  * (a) re-use the arguments for side effects (sizeof is ok)
73  * (b) require any knowledge of processes at this stage
74  */
75 #define put_user(x,ptr) __put_user_check((x),(ptr),sizeof(*(ptr)))
76 #define get_user(x,ptr) __get_user_check((x),(ptr),sizeof(*(ptr)))
77
78 /*
79  * The "__xxx" versions do not do address space checking, useful when
80  * doing multiple accesses to the same area (the user has to do the
81  * checks by hand with "access_ok()")
82  */
83 #define __put_user(x,ptr) __put_user_nocheck((x),(ptr),sizeof(*(ptr)))
84 #define __get_user(x,ptr) __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
85
86 /*
87  * The "xxx_ret" versions return constant specified in third argument, if
88  * something bad happens. These macros can be optimized for the
89  * case of just returning from the function xxx_ret is used.
90  */
91
92 #define put_user_ret(x,ptr,ret) ({ \
93 if (put_user(x,ptr)) return ret; })
94
95 #define get_user_ret(x,ptr,ret) ({ \
96 if (get_user(x,ptr)) return ret; })
97
98 #define __put_user_ret(x,ptr,ret) ({ \
99 if (__put_user(x,ptr)) return ret; })
100
101 #define __get_user_ret(x,ptr,ret) ({ \
102 if (__get_user(x,ptr)) return ret; })
103
104 struct __large_struct { unsigned long buf[100]; };
105 #define __m(x) (*(struct __large_struct *)(x))
106
107 #define __get_user_size(x,ptr,size,retval)                      \
108 do {                                                            \
109         retval = 0;                                             \
110         switch (size) {                                         \
111         case 1:                                                 \
112                 retval = __get_user_asm_b(x, ptr);              \
113                 break;                                          \
114         case 2:                                                 \
115                 retval = __get_user_asm_w(x, ptr);              \
116                 break;                                          \
117         case 4:                                                 \
118                 retval = __get_user_asm_l(x, ptr);              \
119                 break;                                          \
120         case 8:                                                 \
121                 retval = __get_user_asm_q(x, ptr);              \
122                 break;                                          \
123         default:                                                \
124                 __get_user_unknown();                           \
125                 break;                                          \
126         }                                                       \
127 } while (0)
128
129 #define __get_user_nocheck(x,ptr,size)                          \
130 ({                                                              \
131         long __gu_addr = (long)(ptr);                           \
132         long __gu_err;                                          \
133         __typeof(*(ptr)) __gu_val;                              \
134         __asm__ ("":"=r" (__gu_val));                           \
135         __asm__ ("":"=r" (__gu_err));                           \
136         __get_user_size((void *)&__gu_val, __gu_addr, (size), __gu_err); \
137         (x) = (__typeof__(*(ptr))) __gu_val;                    \
138         __gu_err;                                               \
139 })
140
141 #define __get_user_check(x,ptr,size)                            \
142 ({                                                              \
143         long __gu_addr = (long)(ptr);                           \
144         long __gu_err = -EFAULT;                                \
145         __typeof(*(ptr)) __gu_val;                              \
146         __asm__ ("":"=r" (__gu_val));                           \
147         __asm__ ("":"=r" (__gu_err));                           \
148         if (__access_ok(__gu_addr, (size)))                     \
149                 __get_user_size((void *)&__gu_val, __gu_addr, (size), __gu_err); \
150         (x) = (__typeof__(*(ptr))) __gu_val;                    \
151         __gu_err;                                               \
152 })
153
154 extern long __get_user_asm_b(void *, long);
155 extern long __get_user_asm_w(void *, long);
156 extern long __get_user_asm_l(void *, long);
157 extern long __get_user_asm_q(void *, long);
158 extern void __get_user_unknown(void);
159
160 #define __put_user_size(x,ptr,size,retval)                      \
161 do {                                                            \
162         retval = 0;                                             \
163         switch (size) {                                         \
164         case 1:                                                 \
165                 retval = __put_user_asm_b(x, ptr);              \
166                 break;                                          \
167         case 2:                                                 \
168                 retval = __put_user_asm_w(x, ptr);              \
169                 break;                                          \
170         case 4:                                                 \
171                 retval = __put_user_asm_l(x, ptr);              \
172                 break;                                          \
173         case 8:                                                 \
174                 retval = __put_user_asm_q(x, ptr);              \
175                 break;                                          \
176         default:                                                \
177                 __put_user_unknown();                           \
178         }                                                       \
179 } while (0)
180
181 #define __put_user_nocheck(x,ptr,size)                          \
182 ({                                                              \
183         long __pu_err;                                          \
184         __typeof__(*(ptr)) __pu_val = (x);                      \
185         __put_user_size((void *)&__pu_val, (long)(ptr), (size), __pu_err); \
186         __pu_err;                                               \
187 })
188
189 #define __put_user_check(x,ptr,size)                            \
190 ({                                                              \
191         long __pu_err = -EFAULT;                                \
192         long __pu_addr = (long)(ptr);                           \
193         __typeof__(*(ptr)) __pu_val = (x);                      \
194                                                                 \
195         if (__access_ok(__pu_addr, (size)))                     \
196                 __put_user_size((void *)&__pu_val, __pu_addr, (size), __pu_err);\
197         __pu_err;                                               \
198 })
199
200 extern long __put_user_asm_b(void *, long);
201 extern long __put_user_asm_w(void *, long);
202 extern long __put_user_asm_l(void *, long);
203 extern long __put_user_asm_q(void *, long);
204 extern void __put_user_unknown(void);
205
206 \f
207 /* Generic arbitrary sized copy.  */
208 /* Return the number of bytes NOT copied */
209 /* XXX: should be such that: 4byte and the rest. */
210 extern __kernel_size_t __copy_user(void *__to, const void *__from, __kernel_size_t __n);
211
212 #define copy_to_user(to,from,n) ({ \
213 void *__copy_to = (void *) (to); \
214 __kernel_size_t __copy_size = (__kernel_size_t) (n); \
215 __kernel_size_t __copy_res; \
216 if(__copy_size && __access_ok((unsigned long)__copy_to, __copy_size)) { \
217 __copy_res = __copy_user(__copy_to, (void *) (from), __copy_size); \
218 } else __copy_res = __copy_size; \
219 __copy_res; })
220
221 #define copy_to_user_ret(to,from,n,retval) ({ \
222 if (copy_to_user(to,from,n)) \
223         return retval; \
224 })
225
226 #define __copy_to_user(to,from,n)               \
227         __copy_user((void *)(to),               \
228                     (void *)(from), n)
229
230 #define __copy_to_user_ret(to,from,n,retval) ({ \
231 if (__copy_to_user(to,from,n)) \
232         return retval; \
233 })
234
235 #define copy_from_user(to,from,n) ({ \
236 void *__copy_to = (void *) (to); \
237 void *__copy_from = (void *) (from); \
238 __kernel_size_t __copy_size = (__kernel_size_t) (n); \
239 __kernel_size_t __copy_res; \
240 if(__copy_size && __access_ok((unsigned long)__copy_from, __copy_size)) { \
241 __copy_res = __copy_user(__copy_to, __copy_from, __copy_size); \
242 } else __copy_res = __copy_size; \
243 __copy_res; })
244
245 #define copy_from_user_ret(to,from,n,retval) ({ \
246 if (copy_from_user(to,from,n)) \
247         return retval; \
248 })
249
250 #define __copy_from_user(to,from,n)             \
251         __copy_user((void *)(to),               \
252                     (void *)(from), n)
253
254 #define __copy_from_user_ret(to,from,n,retval) ({ \
255 if (__copy_from_user(to,from,n)) \
256         return retval; \
257 })
258
259 #define __copy_to_user_inatomic __copy_to_user
260 #define __copy_from_user_inatomic __copy_from_user
261
262 /* XXX: Not sure it works well..
263    should be such that: 4byte clear and the rest. */
264 extern __kernel_size_t __clear_user(void *addr, __kernel_size_t size);
265
266 #define clear_user(addr,n) ({ \
267 void * __cl_addr = (addr); \
268 unsigned long __cl_size = (n); \
269 if (__cl_size && __access_ok(((unsigned long)(__cl_addr)), __cl_size)) \
270 __cl_size = __clear_user(__cl_addr, __cl_size); \
271 __cl_size; })
272
273 extern int __strncpy_from_user(unsigned long __dest, unsigned long __src, int __count);
274
275 #define strncpy_from_user(dest,src,count) ({ \
276 unsigned long __sfu_src = (unsigned long) (src); \
277 int __sfu_count = (int) (count); \
278 long __sfu_res = -EFAULT; \
279 if(__access_ok(__sfu_src, __sfu_count)) { \
280 __sfu_res = __strncpy_from_user((unsigned long) (dest), __sfu_src, __sfu_count); \
281 } __sfu_res; })
282
283 #define strlen_user(str) strnlen_user(str, ~0UL >> 1)
284
285 /*
286  * Return the size of a string (including the ending 0!)
287  */
288 extern long __strnlen_user(const char *__s, long __n);
289
290 static inline long strnlen_user(const char *s, long n)
291 {
292         if (!__addr_ok(s))
293                 return 0;
294         else
295                 return __strnlen_user(s, n);
296 }
297
298 struct exception_table_entry
299 {
300         unsigned long insn, fixup;
301 };
302
303 #define ARCH_HAS_SEARCH_EXTABLE
304
305 /* If gcc inlines memset, it will use st.q instructions.  Therefore, we need
306    kmalloc allocations to be 8-byte aligned.  Without this, the alignment
307    becomes BYTE_PER_WORD i.e. only 4 (since sizeof(long)==sizeof(void*)==4 on
308    sh64 at the moment). */
309 #define ARCH_KMALLOC_MINALIGN 8
310
311 /*
312  * We want 8-byte alignment for the slab caches as well, otherwise we have
313  * the same BYTES_PER_WORD (sizeof(void *)) min align in kmem_cache_create().
314  */
315 #define ARCH_SLAB_MINALIGN 8
316
317 /* Returns 0 if exception not found and fixup.unit otherwise.  */
318 extern unsigned long search_exception_table(unsigned long addr);
319 extern const struct exception_table_entry *search_exception_tables (unsigned long addr);
320
321 #endif /* __ASM_SH64_UACCESS_H */