b079ac31a6712a76928a16aa0019648fabf51f0b
[linux-2.6.git] / arch / microblaze / include / asm / uaccess.h
1 /*
2  * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
3  * Copyright (C) 2008-2009 PetaLogix
4  * Copyright (C) 2006 Atmark Techno, Inc.
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License. See the file "COPYING" in the main directory of this archive
8  * for more details.
9  */
10
11 #ifndef _ASM_MICROBLAZE_UACCESS_H
12 #define _ASM_MICROBLAZE_UACCESS_H
13
14 #ifdef __KERNEL__
15 #ifndef __ASSEMBLY__
16
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/sched.h> /* RLIMIT_FSIZE */
20 #include <linux/mm.h>
21
22 #include <asm/mmu.h>
23 #include <asm/page.h>
24 #include <asm/pgtable.h>
25 #include <linux/string.h>
26
27 #define VERIFY_READ     0
28 #define VERIFY_WRITE    1
29
30 /*
31  * On Microblaze the fs value is actually the top of the corresponding
32  * address space.
33  *
34  * The fs value determines whether argument validity checking should be
35  * performed or not. If get_fs() == USER_DS, checking is performed, with
36  * get_fs() == KERNEL_DS, checking is bypassed.
37  *
38  * For historical reasons, these macros are grossly misnamed.
39  *
40  * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal.
41  */
42 # define MAKE_MM_SEG(s)       ((mm_segment_t) { (s) })
43
44 #  ifndef CONFIG_MMU
45 #  define KERNEL_DS     MAKE_MM_SEG(0)
46 #  define USER_DS       KERNEL_DS
47 #  else
48 #  define KERNEL_DS     MAKE_MM_SEG(0xFFFFFFFF)
49 #  define USER_DS       MAKE_MM_SEG(TASK_SIZE - 1)
50 #  endif
51
52 # define get_ds()       (KERNEL_DS)
53 # define get_fs()       (current_thread_info()->addr_limit)
54 # define set_fs(val)    (current_thread_info()->addr_limit = (val))
55
56 # define segment_eq(a, b)       ((a).seg == (b).seg)
57
58 /*
59  * The exception table consists of pairs of addresses: the first is the
60  * address of an instruction that is allowed to fault, and the second is
61  * the address at which the program should continue. No registers are
62  * modified, so it is entirely up to the continuation code to figure out
63  * what to do.
64  *
65  * All the routines below use bits of fixup code that are out of line
66  * with the main instruction path. This means when everything is well,
67  * we don't even have to jump over them. Further, they do not intrude
68  * on our cache or tlb entries.
69  */
70 struct exception_table_entry {
71         unsigned long insn, fixup;
72 };
73
74 /* Returns 0 if exception not found and fixup otherwise.  */
75 extern unsigned long search_exception_table(unsigned long);
76
77 #ifndef CONFIG_MMU
78
79 /* Check against bounds of physical memory */
80 static inline int ___range_ok(unsigned long addr, unsigned long size)
81 {
82         return ((addr < memory_start) ||
83                 ((addr + size) > memory_end));
84 }
85
86 #define __range_ok(addr, size) \
87                 ___range_ok((unsigned long)(addr), (unsigned long)(size))
88
89 #define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
90
91 #else
92
93 /*
94  * Address is valid if:
95  *  - "addr", "addr + size" and "size" are all below the limit
96  */
97 #define access_ok(type, addr, size) \
98         (get_fs().seg > (((unsigned long)(addr)) | \
99                 (size) | ((unsigned long)(addr) + (size))))
100
101 /* || printk("access_ok failed for %s at 0x%08lx (size %d), seg 0x%08x\n",
102  type?"WRITE":"READ",addr,size,get_fs().seg)) */
103
104 #endif
105
106 #ifdef CONFIG_MMU
107 # define __FIXUP_SECTION        ".section .fixup,\"ax\"\n"
108 # define __EX_TABLE_SECTION     ".section __ex_table,\"a\"\n"
109 #else
110 # define __FIXUP_SECTION        ".section .discard,\"ax\"\n"
111 # define __EX_TABLE_SECTION     ".section .discard,\"a\"\n"
112 #endif
113
114 extern unsigned long __copy_tofrom_user(void __user *to,
115                 const void __user *from, unsigned long size);
116
117 /* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */
118 static inline unsigned long __must_check __clear_user(void __user *to,
119                                                         unsigned long n)
120 {
121         /* normal memset with two words to __ex_table */
122         __asm__ __volatile__ (                          \
123                         "1:     sb      r0, %2, r0;"    \
124                         "       addik   %0, %0, -1;"    \
125                         "       bneid   %0, 1b;"        \
126                         "       addik   %2, %2, 1;"     \
127                         "2:                     "       \
128                         __EX_TABLE_SECTION              \
129                         ".word  1b,2b;"                 \
130                         ".previous;"                    \
131                 : "=r"(n)                               \
132                 : "0"(n), "r"(to)
133         );
134         return n;
135 }
136
137 static inline unsigned long __must_check clear_user(void __user *to,
138                                                         unsigned long n)
139 {
140         might_sleep();
141         if (unlikely(!access_ok(VERIFY_WRITE, to, n)))
142                 return n;
143
144         return __clear_user(to, n);
145 }
146
147 #ifndef CONFIG_MMU
148
149 extern long __user_bad(void);
150
151 #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err)      \
152 ({                                                              \
153         __asm__ __volatile__ (                                  \
154                         "1:"    insn    " %1, %2, r0;"          \
155                         "       addk    %0, r0, r0;"            \
156                         "2:                     "               \
157                         __FIXUP_SECTION                         \
158                         "3:     brid    2b;"                    \
159                         "       addik   %0, r0, %3;"            \
160                         ".previous;"                            \
161                         __EX_TABLE_SECTION                      \
162                         ".word  1b,3b;"                         \
163                         ".previous;"                            \
164                 : "=&r"(__gu_err), "=r"(__gu_val)               \
165                 : "r"(__gu_ptr), "i"(-EFAULT)                   \
166         );                                                      \
167 })
168
169 /**
170  * get_user: - Get a simple variable from user space.
171  * @x:   Variable to store result.
172  * @ptr: Source address, in user space.
173  *
174  * Context: User context only.  This function may sleep.
175  *
176  * This macro copies a single simple variable from user space to kernel
177  * space.  It supports simple types like char and int, but not larger
178  * data types like structures or arrays.
179  *
180  * @ptr must have pointer-to-simple-variable type, and the result of
181  * dereferencing @ptr must be assignable to @x without a cast.
182  *
183  * Returns zero on success, or -EFAULT on error.
184  * On error, the variable @x is set to zero.
185  */
186
187 #define __get_user(x, ptr)                                              \
188 ({                                                                      \
189         unsigned long __gu_val;                                         \
190         /*unsigned long __gu_ptr = (unsigned long)(ptr);*/              \
191         long __gu_err;                                                  \
192         switch (sizeof(*(ptr))) {                                       \
193         case 1:                                                         \
194                 __get_user_asm("lbu", (ptr), __gu_val, __gu_err);       \
195                 break;                                                  \
196         case 2:                                                         \
197                 __get_user_asm("lhu", (ptr), __gu_val, __gu_err);       \
198                 break;                                                  \
199         case 4:                                                         \
200                 __get_user_asm("lw", (ptr), __gu_val, __gu_err);        \
201                 break;                                                  \
202         default:                                                        \
203                 /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
204         }                                                               \
205         x = (__typeof__(*(ptr))) __gu_val;                              \
206         __gu_err;                                                       \
207 })
208
209
210 #define get_user(x, ptr)                                                \
211 ({                                                                      \
212         access_ok(VERIFY_READ, (ptr), sizeof(*(ptr)))                   \
213                 ? __get_user((x), (ptr)) : -EFAULT;                     \
214 })
215
216 /* Undefined function to trigger linker error */
217 extern int bad_user_access_length(void);
218
219 /* FIXME is not there defined __pu_val */
220 #define __put_user(var, ptr)                                    \
221 ({                                                              \
222         int __pu_err = 0;                                       \
223         switch (sizeof(*(ptr))) {                               \
224         case 1:                                                 \
225         case 2:                                                 \
226         case 4:                                                 \
227                 *(ptr) = (var);                                 \
228                 break;                                          \
229         case 8: {                                               \
230                 typeof(*(ptr)) __pu_val = (var);                \
231                 memcpy(ptr, &__pu_val, sizeof(__pu_val));       \
232                 }                                               \
233                 break;                                          \
234         default:                                                \
235                 __pu_err = __put_user_bad();                    \
236                 break;                                          \
237         }                                                       \
238         __pu_err;                                               \
239 })
240
241 #define __put_user_bad()        (bad_user_access_length(), (-EFAULT))
242
243 #define put_user(x, ptr)        __put_user((x), (ptr))
244
245 #define copy_to_user(to, from, n)       (memcpy((to), (from), (n)), 0)
246 #define copy_from_user(to, from, n)     (memcpy((to), (from), (n)), 0)
247
248 #define __copy_to_user(to, from, n)     (copy_to_user((to), (from), (n)))
249 #define __copy_from_user(to, from, n)   (copy_from_user((to), (from), (n)))
250 #define __copy_to_user_inatomic(to, from, n) \
251                         (__copy_to_user((to), (from), (n)))
252 #define __copy_from_user_inatomic(to, from, n) \
253                         (__copy_from_user((to), (from), (n)))
254
255 extern long strncpy_from_user(char *dst, const char *src, long count);
256 extern long strnlen_user(const char *src, long count);
257
258 #else /* CONFIG_MMU */
259
260 /* put_user and get_user macros */
261
262 extern long __user_bad(void);
263
264 #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err)      \
265 ({                                                              \
266         __asm__ __volatile__ (                                  \
267                         "1:"    insn    " %1, %2, r0;"          \
268                         "       addk    %0, r0, r0;"            \
269                         "2:                     "               \
270                         __FIXUP_SECTION                         \
271                         "3:     brid    2b;     "               \
272                         "       addik   %0, r0, %3;"            \
273                         ".previous;"                            \
274                         __EX_TABLE_SECTION                      \
275                         ".word  1b,3b;"                         \
276                         ".previous;"                            \
277                 : "=&r"(__gu_err), "=r"(__gu_val)               \
278                 : "r"(__gu_ptr), "i"(-EFAULT)                   \
279         );                                                      \
280 })
281
282 #define __get_user(x, ptr)                                              \
283 ({                                                                      \
284         unsigned long __gu_val;                                         \
285         /*unsigned long __gu_ptr = (unsigned long)(ptr);*/              \
286         long __gu_err;                                                  \
287         switch (sizeof(*(ptr))) {                                       \
288         case 1:                                                         \
289                 __get_user_asm("lbu", (ptr), __gu_val, __gu_err);       \
290                 break;                                                  \
291         case 2:                                                         \
292                 __get_user_asm("lhu", (ptr), __gu_val, __gu_err);       \
293                 break;                                                  \
294         case 4:                                                         \
295                 __get_user_asm("lw", (ptr), __gu_val, __gu_err);        \
296                 break;                                                  \
297         default:                                                        \
298                 /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
299         }                                                               \
300         x = (__typeof__(*(ptr))) __gu_val;                              \
301         __gu_err;                                                       \
302 })
303
304 /**
305  * get_user: - Get a simple variable from user space.
306  * @x:   Variable to store result.
307  * @ptr: Source address, in user space.
308  *
309  * Context: User context only.  This function may sleep.
310  *
311  * This macro copies a single simple variable from user space to kernel
312  * space.  It supports simple types like char and int, but not larger
313  * data types like structures or arrays.
314  *
315  * @ptr must have pointer-to-simple-variable type, and the result of
316  * dereferencing @ptr must be assignable to @x without a cast.
317  *
318  * Returns zero on success, or -EFAULT on error.
319  * On error, the variable @x is set to zero.
320  */
321
322 #define get_user(x, ptr)                                                \
323 ({                                                                      \
324         access_ok(VERIFY_READ, (ptr), sizeof(*(ptr)))                   \
325                 ? __get_user((x), (ptr)) : -EFAULT;                     \
326 })
327
328 /**
329  * put_user: - Write a simple value into user space.
330  * @x:   Value to copy to user space.
331  * @ptr: Destination address, in user space.
332  *
333  * Context: User context only.  This function may sleep.
334  *
335  * This macro copies a single simple value from kernel space to user
336  * space.  It supports simple types like char and int, but not larger
337  * data types like structures or arrays.
338  *
339  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
340  * to the result of dereferencing @ptr.
341  *
342  * Returns zero on success, or -EFAULT on error.
343  */
344
345 #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err)      \
346 ({                                                              \
347         __asm__ __volatile__ (                                  \
348                         "1:"    insn    " %1, %2, r0;"          \
349                         "       addk    %0, r0, r0;"            \
350                         "2:                     "               \
351                         __FIXUP_SECTION                         \
352                         "3:     brid    2b;"                    \
353                         "       addik   %0, r0, %3;"            \
354                         ".previous;"                            \
355                         __EX_TABLE_SECTION                      \
356                         ".word  1b,3b;"                         \
357                         ".previous;"                            \
358                 : "=&r"(__gu_err)                               \
359                 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT)    \
360         );                                                      \
361 })
362
363 #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err)          \
364 ({                                                              \
365         __asm__ __volatile__ (" lwi     %0, %1, 0;"             \
366                         "1:     swi     %0, %2, 0;"             \
367                         "       lwi     %0, %1, 4;"             \
368                         "2:     swi     %0, %2, 4;"             \
369                         "       addk    %0, r0, r0;"            \
370                         "3:                             "       \
371                         __FIXUP_SECTION                         \
372                         "4:     brid    3b;"                    \
373                         "       addik   %0, r0, %3;"            \
374                         ".previous;"                            \
375                         __EX_TABLE_SECTION                      \
376                         ".word  1b,4b,2b,4b;"                   \
377                         ".previous;"                            \
378                 : "=&r"(__gu_err)                               \
379                 : "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT)   \
380                 );                                              \
381 })
382
383 #define __put_user(x, ptr)                                              \
384 ({                                                                      \
385         __typeof__(*(ptr)) volatile __gu_val = (x);                     \
386         long __gu_err = 0;                                              \
387         switch (sizeof(__gu_val)) {                                     \
388         case 1:                                                         \
389                 __put_user_asm("sb", (ptr), __gu_val, __gu_err);        \
390                 break;                                                  \
391         case 2:                                                         \
392                 __put_user_asm("sh", (ptr), __gu_val, __gu_err);        \
393                 break;                                                  \
394         case 4:                                                         \
395                 __put_user_asm("sw", (ptr), __gu_val, __gu_err);        \
396                 break;                                                  \
397         case 8:                                                         \
398                 __put_user_asm_8((ptr), __gu_val, __gu_err);            \
399                 break;                                                  \
400         default:                                                        \
401                 /*__gu_err = -EINVAL;*/ __gu_err = __user_bad();        \
402         }                                                               \
403         __gu_err;                                                       \
404 })
405
406 #define put_user(x, ptr)                                                \
407 ({                                                                      \
408         access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr)))                  \
409                 ? __put_user((x), (ptr)) : -EFAULT;                     \
410 })
411
412 #define __copy_from_user(to, from, n)   \
413         __copy_tofrom_user((__force void __user *)(to), \
414                                 (void __user *)(from), (n))
415 #define __copy_from_user_inatomic(to, from, n) \
416                 copy_from_user((to), (from), (n))
417
418 static inline long copy_from_user(void *to,
419                 const void __user *from, unsigned long n)
420 {
421         might_sleep();
422         if (access_ok(VERIFY_READ, from, n))
423                 return __copy_from_user(to, from, n);
424         else
425                 return n;
426 }
427
428 #define __copy_to_user(to, from, n)     \
429                 __copy_tofrom_user((void __user *)(to), \
430                         (__force const void __user *)(from), (n))
431 #define __copy_to_user_inatomic(to, from, n)    copy_to_user((to), (from), (n))
432
433 static inline long copy_to_user(void __user *to,
434                 const void *from, unsigned long n)
435 {
436         might_sleep();
437         if (access_ok(VERIFY_WRITE, to, n))
438                 return __copy_to_user(to, from, n);
439         else
440                 return n;
441 }
442
443 extern int __strncpy_user(char *to, const char __user *from, int len);
444
445 #define __strncpy_from_user     __strncpy_user
446
447 static inline long
448 strncpy_from_user(char *dst, const char __user *src, long count)
449 {
450         if (!access_ok(VERIFY_READ, src, 1))
451                 return -EFAULT;
452         return __strncpy_from_user(dst, src, count);
453 }
454
455 extern int __strnlen_user(const char __user *sstr, int len);
456
457 #define strnlen_user(str, len)  \
458                 (access_ok(VERIFY_READ, str, 1) ? __strnlen_user(str, len) : 0)
459
460 #endif /* CONFIG_MMU */
461
462 #endif  /* __ASSEMBLY__ */
463 #endif /* __KERNEL__ */
464
465 #endif /* _ASM_MICROBLAZE_UACCESS_H */