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[SERIAL] Update serial driver documentation
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / include / asm-x86_64 / uaccess.h
blobbddffcb591b8b26c1068292c459d3d1ae446350b
1 #ifndef __X86_64_UACCESS_H
2 #define __X86_64_UACCESS_H
3
4 /*
5 * User space memory access functions
6 */
7 #include <linux/config.h>
8 #include <linux/compiler.h>
9 #include <linux/errno.h>
10 #include <linux/sched.h>
11 #include <linux/prefetch.h>
12 #include <asm/page.h>
13
14 #define VERIFY_READ 0
15 #define VERIFY_WRITE 1
16
17 /*
18 * The fs value determines whether argument validity checking should be
19 * performed or not. If get_fs() == USER_DS, checking is performed, with
20 * get_fs() == KERNEL_DS, checking is bypassed.
21 *
22 * For historical reasons, these macros are grossly misnamed.
23 */
24
25 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
26
27 #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFFFFFFFFFUL)
28 #define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
29
30 #define get_ds() (KERNEL_DS)
31 #define get_fs() (current_thread_info()->addr_limit)
32 #define set_fs(x) (current_thread_info()->addr_limit = (x))
33
34 #define segment_eq(a,b) ((a).seg == (b).seg)
35
36 #define __addr_ok(addr) (!((unsigned long)(addr) & (current_thread_info()->addr_limit.seg)))
37
38 /*
39 * Uhhuh, this needs 65-bit arithmetic. We have a carry..
40 */
41 #define __range_not_ok(addr,size) ({ \
42 unsigned long flag,sum; \
43 __chk_user_ptr(addr); \
44 asm("# range_ok\n\r" \
45 "addq %3,%1 ; sbbq %0,%0 ; cmpq %1,%4 ; sbbq $0,%0" \
46 :"=&r" (flag), "=r" (sum) \
47 :"1" (addr),"g" ((long)(size)),"g" (current_thread_info()->addr_limit.seg)); \
48 flag; })
49
50 #define access_ok(type, addr, size) (__range_not_ok(addr,size) == 0)
51
52 /*
53 * The exception table consists of pairs of addresses: the first is the
54 * address of an instruction that is allowed to fault, and the second is
55 * the address at which the program should continue. No registers are
56 * modified, so it is entirely up to the continuation code to figure out
57 * what to do.
58 *
59 * All the routines below use bits of fixup code that are out of line
60 * with the main instruction path. This means when everything is well,
61 * we don't even have to jump over them. Further, they do not intrude
62 * on our cache or tlb entries.
63 */
64
65 struct exception_table_entry
66 {
67 unsigned long insn, fixup;
68 };
69
70 #define ARCH_HAS_SEARCH_EXTABLE
71
72 /*
73 * These are the main single-value transfer routines. They automatically
74 * use the right size if we just have the right pointer type.
75 *
76 * This gets kind of ugly. We want to return _two_ values in "get_user()"
77 * and yet we don't want to do any pointers, because that is too much
78 * of a performance impact. Thus we have a few rather ugly macros here,
79 * and hide all the ugliness from the user.
80 *
81 * The "__xxx" versions of the user access functions are versions that
82 * do not verify the address space, that must have been done previously
83 * with a separate "access_ok()" call (this is used when we do multiple
84 * accesses to the same area of user memory).
85 */
86
87 #define __get_user_x(size,ret,x,ptr) \
88 __asm__ __volatile__("call __get_user_" #size \
89 :"=a" (ret),"=d" (x) \
90 :"c" (ptr) \
91 :"r8")
92
93 /* Careful: we have to cast the result to the type of the pointer for sign reasons */
94 #define get_user(x,ptr) \
95 ({ unsigned long __val_gu; \
96 int __ret_gu; \
97 __chk_user_ptr(ptr); \
98 switch(sizeof (*(ptr))) { \
99 case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \
100 case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \
101 case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \
102 case 8: __get_user_x(8,__ret_gu,__val_gu,ptr); break; \
103 default: __get_user_bad(); break; \
104 } \
105 (x) = (__typeof__(*(ptr)))__val_gu; \
106 __ret_gu; \
107 })
108
109 extern void __put_user_1(void);
110 extern void __put_user_2(void);
111 extern void __put_user_4(void);
112 extern void __put_user_8(void);
113 extern void __put_user_bad(void);
114
115 #define __put_user_x(size,ret,x,ptr) \
116 __asm__ __volatile__("call __put_user_" #size \
117 :"=a" (ret) \
118 :"c" (ptr),"d" (x) \
119 :"r8")
120
121 #define put_user(x,ptr) \
122 __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
123
124 #define __get_user(x,ptr) \
125 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
126 #define __put_user(x,ptr) \
127 __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
128
129 #define __get_user_unaligned __get_user
130 #define __put_user_unaligned __put_user
131
132 #define __put_user_nocheck(x,ptr,size) \
133 ({ \
134 int __pu_err; \
135 __put_user_size((x),(ptr),(size),__pu_err); \
136 __pu_err; \
137 })
138
139
140 #define __put_user_check(x,ptr,size) \
141 ({ \
142 int __pu_err; \
143 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
144 switch (size) { \
145 case 1: __put_user_x(1,__pu_err,x,__pu_addr); break; \
146 case 2: __put_user_x(2,__pu_err,x,__pu_addr); break; \
147 case 4: __put_user_x(4,__pu_err,x,__pu_addr); break; \
148 case 8: __put_user_x(8,__pu_err,x,__pu_addr); break; \
149 default: __put_user_bad(); \
150 } \
151 __pu_err; \
152 })
153
154 #define __put_user_size(x,ptr,size,retval) \
155 do { \
156 retval = 0; \
157 __chk_user_ptr(ptr); \
158 switch (size) { \
159 case 1: __put_user_asm(x,ptr,retval,"b","b","iq",-EFAULT); break;\
160 case 2: __put_user_asm(x,ptr,retval,"w","w","ir",-EFAULT); break;\
161 case 4: __put_user_asm(x,ptr,retval,"l","k","ir",-EFAULT); break;\
162 case 8: __put_user_asm(x,ptr,retval,"q","","ir",-EFAULT); break;\
163 default: __put_user_bad(); \
164 } \
165 } while (0)
166
167 /* FIXME: this hack is definitely wrong -AK */
168 struct __large_struct { unsigned long buf[100]; };
169 #define __m(x) (*(struct __large_struct __user *)(x))
170
171 /*
172 * Tell gcc we read from memory instead of writing: this is because
173 * we do not write to any memory gcc knows about, so there are no
174 * aliasing issues.
175 */
176 #define __put_user_asm(x, addr, err, itype, rtype, ltype, errno) \
177 __asm__ __volatile__( \
178 "1: mov"itype" %"rtype"1,%2\n" \
179 "2:\n" \
180 ".section .fixup,\"ax\"\n" \
181 "3: mov %3,%0\n" \
182 " jmp 2b\n" \
183 ".previous\n" \
184 ".section __ex_table,\"a\"\n" \
185 " .align 8\n" \
186 " .quad 1b,3b\n" \
187 ".previous" \
188 : "=r"(err) \
189 : ltype (x), "m"(__m(addr)), "i"(errno), "0"(err))
190
191
192 #define __get_user_nocheck(x,ptr,size) \
193 ({ \
194 int __gu_err; \
195 unsigned long __gu_val; \
196 __get_user_size(__gu_val,(ptr),(size),__gu_err); \
197 (x) = (__typeof__(*(ptr)))__gu_val; \
198 __gu_err; \
199 })
200
201 extern int __get_user_1(void);
202 extern int __get_user_2(void);
203 extern int __get_user_4(void);
204 extern int __get_user_8(void);
205 extern int __get_user_bad(void);
206
207 #define __get_user_size(x,ptr,size,retval) \
208 do { \
209 retval = 0; \
210 __chk_user_ptr(ptr); \
211 switch (size) { \
212 case 1: __get_user_asm(x,ptr,retval,"b","b","=q",-EFAULT); break;\
213 case 2: __get_user_asm(x,ptr,retval,"w","w","=r",-EFAULT); break;\
214 case 4: __get_user_asm(x,ptr,retval,"l","k","=r",-EFAULT); break;\
215 case 8: __get_user_asm(x,ptr,retval,"q","","=r",-EFAULT); break;\
216 default: (x) = __get_user_bad(); \
217 } \
218 } while (0)
219
220 #define __get_user_asm(x, addr, err, itype, rtype, ltype, errno) \
221 __asm__ __volatile__( \
222 "1: mov"itype" %2,%"rtype"1\n" \
223 "2:\n" \
224 ".section .fixup,\"ax\"\n" \
225 "3: mov %3,%0\n" \
226 " xor"itype" %"rtype"1,%"rtype"1\n" \
227 " jmp 2b\n" \
228 ".previous\n" \
229 ".section __ex_table,\"a\"\n" \
230 " .align 8\n" \
231 " .quad 1b,3b\n" \
232 ".previous" \
233 : "=r"(err), ltype (x) \
234 : "m"(__m(addr)), "i"(errno), "0"(err))
235
236 /*
237 * Copy To/From Userspace
238 */
239
240 /* Handles exceptions in both to and from, but doesn't do access_ok */
241 extern unsigned long copy_user_generic(void *to, const void *from, unsigned len);
242
243 extern unsigned long copy_to_user(void __user *to, const void *from, unsigned len);
244 extern unsigned long copy_from_user(void *to, const void __user *from, unsigned len);
245 extern unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len);
246
247 static __always_inline int __copy_from_user(void *dst, const void __user *src, unsigned size)
248 {
249 int ret = 0;
250 if (!__builtin_constant_p(size))
251 return copy_user_generic(dst,(__force void *)src,size);
252 switch (size) {
253 case 1:__get_user_asm(*(u8*)dst,(u8 __user *)src,ret,"b","b","=q",1);
254 return ret;
255 case 2:__get_user_asm(*(u16*)dst,(u16 __user *)src,ret,"w","w","=r",2);
256 return ret;
257 case 4:__get_user_asm(*(u32*)dst,(u32 __user *)src,ret,"l","k","=r",4);
258 return ret;
259 case 8:__get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",8);
260 return ret;
261 case 10:
262 __get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",16);
263 if (unlikely(ret)) return ret;
264 __get_user_asm(*(u16*)(8+(char*)dst),(u16 __user *)(8+(char __user *)src),ret,"w","w","=r",2);
265 return ret;
266 case 16:
267 __get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",16);
268 if (unlikely(ret)) return ret;
269 __get_user_asm(*(u64*)(8+(char*)dst),(u64 __user *)(8+(char __user *)src),ret,"q","","=r",8);
270 return ret;
271 default:
272 return copy_user_generic(dst,(__force void *)src,size);
273 }
274 }
275
276 static __always_inline int __copy_to_user(void __user *dst, const void *src, unsigned size)
277 {
278 int ret = 0;
279 if (!__builtin_constant_p(size))
280 return copy_user_generic((__force void *)dst,src,size);
281 switch (size) {
282 case 1:__put_user_asm(*(u8*)src,(u8 __user *)dst,ret,"b","b","iq",1);
283 return ret;
284 case 2:__put_user_asm(*(u16*)src,(u16 __user *)dst,ret,"w","w","ir",2);
285 return ret;
286 case 4:__put_user_asm(*(u32*)src,(u32 __user *)dst,ret,"l","k","ir",4);
287 return ret;
288 case 8:__put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",8);
289 return ret;
290 case 10:
291 __put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",10);
292 if (unlikely(ret)) return ret;
293 asm("":::"memory");
294 __put_user_asm(4[(u16*)src],4+(u16 __user *)dst,ret,"w","w","ir",2);
295 return ret;
296 case 16:
297 __put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",16);
298 if (unlikely(ret)) return ret;
299 asm("":::"memory");
300 __put_user_asm(1[(u64*)src],1+(u64 __user *)dst,ret,"q","","ir",8);
301 return ret;
302 default:
303 return copy_user_generic((__force void *)dst,src,size);
304 }
305 }
306
307
308 static __always_inline int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
309 {
310 int ret = 0;
311 if (!__builtin_constant_p(size))
312 return copy_user_generic((__force void *)dst,(__force void *)src,size);
313 switch (size) {
314 case 1: {
315 u8 tmp;
316 __get_user_asm(tmp,(u8 __user *)src,ret,"b","b","=q",1);
317 if (likely(!ret))
318 __put_user_asm(tmp,(u8 __user *)dst,ret,"b","b","iq",1);
319 return ret;
320 }
321 case 2: {
322 u16 tmp;
323 __get_user_asm(tmp,(u16 __user *)src,ret,"w","w","=r",2);
324 if (likely(!ret))
325 __put_user_asm(tmp,(u16 __user *)dst,ret,"w","w","ir",2);
326 return ret;
327 }
328
329 case 4: {
330 u32 tmp;
331 __get_user_asm(tmp,(u32 __user *)src,ret,"l","k","=r",4);
332 if (likely(!ret))
333 __put_user_asm(tmp,(u32 __user *)dst,ret,"l","k","ir",4);
334 return ret;
335 }
336 case 8: {
337 u64 tmp;
338 __get_user_asm(tmp,(u64 __user *)src,ret,"q","","=r",8);
339 if (likely(!ret))
340 __put_user_asm(tmp,(u64 __user *)dst,ret,"q","","ir",8);
341 return ret;
342 }
343 default:
344 return copy_user_generic((__force void *)dst,(__force void *)src,size);
345 }
346 }
347
348 long strncpy_from_user(char *dst, const char __user *src, long count);
349 long __strncpy_from_user(char *dst, const char __user *src, long count);
350 long strnlen_user(const char __user *str, long n);
351 long __strnlen_user(const char __user *str, long n);
352 long strlen_user(const char __user *str);
353 unsigned long clear_user(void __user *mem, unsigned long len);
354 unsigned long __clear_user(void __user *mem, unsigned long len);
355
356 #define __copy_to_user_inatomic __copy_to_user
357 #define __copy_from_user_inatomic __copy_from_user
358
359 #endif /* __X86_64_UACCESS_H */
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