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Linux v2.6.15-rc6
[pohmelfs.git] / include / asm-frv / uaccess.h
blob991b50fbba24d77b64c402389f2e93e0c48bb2a8
1 /* uaccess.h: userspace accessor functions
2 *
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12 #ifndef _ASM_UACCESS_H
13 #define _ASM_UACCESS_H
14
15 /*
16 * User space memory access functions
17 */
18 #include <linux/sched.h>
19 #include <linux/mm.h>
20 #include <asm/segment.h>
21 #include <asm/sections.h>
22
23 #define HAVE_ARCH_UNMAPPED_AREA /* we decide where to put mmaps */
24
25 #define __ptr(x) ((unsigned long *)(x))
26
27 #define VERIFY_READ 0
28 #define VERIFY_WRITE 1
29
30 #define __addr_ok(addr) ((unsigned long)(addr) < get_addr_limit())
31
32 /*
33 * check that a range of addresses falls within the current address limit
34 */
35 static inline int ___range_ok(unsigned long addr, unsigned long size)
36 {
37 #ifdef CONFIG_MMU
38 int flag = -EFAULT, tmp;
39
40 asm volatile (
41 " addcc %3,%2,%1,icc0 \n" /* set C-flag if addr+size>4GB */
42 " subcc.p %1,%4,gr0,icc1 \n" /* jump if addr+size>limit */
43 " bc icc0,#0,0f \n"
44 " bhi icc1,#0,0f \n"
45 " setlos #0,%0 \n" /* mark okay */
46 "0: \n"
47 : "=r"(flag), "=&r"(tmp)
48 : "r"(addr), "r"(size), "r"(get_addr_limit()), "0"(flag)
49 );
50
51 return flag;
52
53 #else
54
55 if (addr < memory_start ||
56 addr > memory_end ||
57 size > memory_end - memory_start ||
58 addr + size > memory_end)
59 return -EFAULT;
60
61 return 0;
62 #endif
63 }
64
65 #define __range_ok(addr,size) ___range_ok((unsigned long) (addr), (unsigned long) (size))
66
67 #define access_ok(type,addr,size) (__range_ok((addr), (size)) == 0)
68 #define __access_ok(addr,size) (__range_ok((addr), (size)) == 0)
69
70 /*
71 * The exception table consists of pairs of addresses: the first is the
72 * address of an instruction that is allowed to fault, and the second is
73 * the address at which the program should continue. No registers are
74 * modified, so it is entirely up to the continuation code to figure out
75 * what to do.
76 *
77 * All the routines below use bits of fixup code that are out of line
78 * with the main instruction path. This means when everything is well,
79 * we don't even have to jump over them. Further, they do not intrude
80 * on our cache or tlb entries.
81 */
82 struct exception_table_entry
83 {
84 unsigned long insn, fixup;
85 };
86
87 /* Returns 0 if exception not found and fixup otherwise. */
88 extern unsigned long search_exception_table(unsigned long);
89
90
91 /*
92 * These are the main single-value transfer routines. They automatically
93 * use the right size if we just have the right pointer type.
94 */
95 #define __put_user(x, ptr) \
96 ({ \
97 int __pu_err = 0; \
98 \
99 typeof(*(ptr)) __pu_val = (x); \
100 \
101 switch (sizeof (*(ptr))) { \
102 case 1: \
103 __put_user_asm(__pu_err, __pu_val, ptr, "b", "r"); \
104 break; \
105 case 2: \
106 __put_user_asm(__pu_err, __pu_val, ptr, "h", "r"); \
107 break; \
108 case 4: \
109 __put_user_asm(__pu_err, __pu_val, ptr, "", "r"); \
110 break; \
111 case 8: \
112 __put_user_asm(__pu_err, __pu_val, ptr, "d", "e"); \
113 break; \
114 default: \
115 __pu_err = __put_user_bad(); \
116 break; \
117 } \
118 __pu_err; \
119 })
120
121 #define put_user(x, ptr) \
122 ({ \
123 typeof(&*ptr) _p = (ptr); \
124 int _e; \
125 \
126 _e = __range_ok(_p, sizeof(*_p)); \
127 if (_e == 0) \
128 _e = __put_user((x), _p); \
129 _e; \
130 })
131
132 extern int __put_user_bad(void);
133
134 /*
135 * Tell gcc we read from memory instead of writing: this is because
136 * we do not write to any memory gcc knows about, so there are no
137 * aliasing issues.
138 */
139
140 #ifdef CONFIG_MMU
141
142 #define __put_user_asm(err,x,ptr,dsize,constraint) \
143 do { \
144 asm volatile("1: st"dsize"%I1 %2,%M1 \n" \
145 "2: \n" \
146 ".subsection 2 \n" \
147 "3: setlos %3,%0 \n" \
148 " bra 2b \n" \
149 ".previous \n" \
150 ".section __ex_table,\"a\" \n" \
151 " .balign 8 \n" \
152 " .long 1b,3b \n" \
153 ".previous" \
154 : "=r" (err) \
155 : "m" (*__ptr(ptr)), constraint (x), "i"(-EFAULT), "0"(err) \
156 : "memory"); \
157 } while (0)
158
159 #else
160
161 #define __put_user_asm(err,x,ptr,bwl,con) \
162 do { \
163 asm(" st"bwl"%I0 %1,%M0 \n" \
164 " membar \n" \
165 : \
166 : "m" (*__ptr(ptr)), con (x) \
167 : "memory"); \
168 } while (0)
169
170 #endif
171
172 /*****************************************************************************/
173 /*
174 *
175 */
176 #define __get_user(x, ptr) \
177 ({ \
178 typeof(*(ptr)) __gu_val = 0; \
179 int __gu_err = 0; \
180 \
181 switch (sizeof(*(ptr))) { \
182 case 1: \
183 __get_user_asm(__gu_err, __gu_val, ptr, "ub", "=r"); \
184 break; \
185 case 2: \
186 __get_user_asm(__gu_err, __gu_val, ptr, "uh", "=r"); \
187 break; \
188 case 4: \
189 __get_user_asm(__gu_err, __gu_val, ptr, "", "=r"); \
190 break; \
191 case 8: \
192 __get_user_asm(__gu_err, __gu_val, ptr, "d", "=e"); \
193 break; \
194 default: \
195 __gu_err = __get_user_bad(); \
196 break; \
197 } \
198 (x) = __gu_val; \
199 __gu_err; \
200 })
201
202 #define get_user(x, ptr) \
203 ({ \
204 typeof(&*ptr) _p = (ptr); \
205 int _e; \
206 \
207 _e = __range_ok(_p, sizeof(*_p)); \
208 if (likely(_e == 0)) \
209 _e = __get_user((x), _p); \
210 else \
211 (x) = (typeof(x)) 0; \
212 _e; \
213 })
214
215 extern int __get_user_bad(void);
216
217 #ifdef CONFIG_MMU
218
219 #define __get_user_asm(err,x,ptr,dtype,constraint) \
220 do { \
221 asm("1: ld"dtype"%I2 %M2,%1 \n" \
222 "2: \n" \
223 ".subsection 2 \n" \
224 "3: setlos %3,%0 \n" \
225 " setlos #0,%1 \n" \
226 " bra 2b \n" \
227 ".previous \n" \
228 ".section __ex_table,\"a\" \n" \
229 " .balign 8 \n" \
230 " .long 1b,3b \n" \
231 ".previous" \
232 : "=r" (err), constraint (x) \
233 : "m" (*__ptr(ptr)), "i"(-EFAULT), "0"(err) \
234 ); \
235 } while(0)
236
237 #else
238
239 #define __get_user_asm(err,x,ptr,bwl,con) \
240 asm(" ld"bwl"%I1 %M1,%0 \n" \
241 " membar \n" \
242 : con(x) \
243 : "m" (*__ptr(ptr)))
244
245 #endif
246
247 /*****************************************************************************/
248 /*
249 *
250 */
251 #ifdef CONFIG_MMU
252 extern long __memset_user(void *dst, unsigned long count);
253 extern long __memcpy_user(void *dst, const void *src, unsigned long count);
254
255 #define clear_user(dst,count) __memset_user((dst), (count))
256 #define __copy_from_user_inatomic(to, from, n) __memcpy_user((to), (from), (n))
257 #define __copy_to_user_inatomic(to, from, n) __memcpy_user((to), (from), (n))
258
259 #else
260
261 #define clear_user(dst,count) (memset((dst), 0, (count)), 0)
262 #define __copy_from_user_inatomic(to, from, n) (memcpy((to), (from), (n)), 0)
263 #define __copy_to_user_inatomic(to, from, n) (memcpy((to), (from), (n)), 0)
264
265 #endif
266
267 static inline unsigned long __must_check
268 __copy_to_user(void __user *to, const void *from, unsigned long n)
269 {
270 might_sleep();
271 return __copy_to_user_inatomic(to, from, n);
272 }
273
274 static inline unsigned long
275 __copy_from_user(void *to, const void __user *from, unsigned long n)
276 {
277 might_sleep();
278 return __copy_from_user_inatomic(to, from, n);
279 }
280
281 static inline long copy_from_user(void *to, const void *from, unsigned long n)
282 {
283 unsigned long ret = n;
284
285 if (likely(__access_ok(from, n)))
286 ret = __copy_from_user(to, from, n);
287
288 if (unlikely(ret != 0))
289 memset(to + (n - ret), 0, ret);
290
291 return ret;
292 }
293
294 static inline long copy_to_user(void *to, const void *from, unsigned long n)
295 {
296 return likely(__access_ok(to, n)) ? __copy_to_user(to, from, n) : n;
297 }
298
299 #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
300 #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
301
302 extern long strncpy_from_user(char *dst, const char *src, long count);
303 extern long strnlen_user(const char *src, long count);
304
305 #define strlen_user(str) strnlen_user(str, 32767)
306
307 extern unsigned long search_exception_table(unsigned long addr);
308
309 #define copy_to_user_page(vma, page, vaddr, dst, src, len) memcpy(dst, src, len)
310 #define copy_from_user_page(vma, page, vaddr, dst, src, len) memcpy(dst, src, len)
311
312 #endif /* _ASM_UACCESS_H */