Merge branch 'master' into percpu
[pandora-kernel.git] / arch / blackfin / include / asm / uaccess.h
1 /*
2  * Copyright 2004-2009 Analog Devices Inc.
3  *
4  * Licensed under the GPL-2 or later.
5  *
6  * Based on: include/asm-m68knommu/uaccess.h
7  */
8
9 #ifndef __BLACKFIN_UACCESS_H
10 #define __BLACKFIN_UACCESS_H
11
12 /*
13  * User space memory access functions
14  */
15 #include <linux/sched.h>
16 #include <linux/mm.h>
17 #include <linux/string.h>
18
19 #include <asm/segment.h>
20 #include <asm/sections.h>
21
22 #define get_ds()        (KERNEL_DS)
23 #define get_fs()        (current_thread_info()->addr_limit)
24
25 static inline void set_fs(mm_segment_t fs)
26 {
27         current_thread_info()->addr_limit = fs;
28 }
29
30 #define segment_eq(a,b) ((a) == (b))
31
32 #define VERIFY_READ     0
33 #define VERIFY_WRITE    1
34
35 #define access_ok(type, addr, size) _access_ok((unsigned long)(addr), (size))
36
37 static inline int is_in_rom(unsigned long addr)
38 {
39         /*
40          * What we are really trying to do is determine if addr is
41          * in an allocated kernel memory region. If not then assume
42          * we cannot free it or otherwise de-allocate it. Ideally
43          * we could restrict this to really being in a ROM or flash,
44          * but that would need to be done on a board by board basis,
45          * not globally.
46          */
47         if ((addr < _ramstart) || (addr >= _ramend))
48                 return (1);
49
50         /* Default case, not in ROM */
51         return (0);
52 }
53
54 /*
55  * The fs value determines whether argument validity checking should be
56  * performed or not.  If get_fs() == USER_DS, checking is performed, with
57  * get_fs() == KERNEL_DS, checking is bypassed.
58  */
59
60 #ifndef CONFIG_ACCESS_CHECK
61 static inline int _access_ok(unsigned long addr, unsigned long size) { return 1; }
62 #else
63 extern int _access_ok(unsigned long addr, unsigned long size);
64 #endif
65
66 /*
67  * The exception table consists of pairs of addresses: the first is the
68  * address of an instruction that is allowed to fault, and the second is
69  * the address at which the program should continue.  No registers are
70  * modified, so it is entirely up to the continuation code to figure out
71  * what to do.
72  *
73  * All the routines below use bits of fixup code that are out of line
74  * with the main instruction path.  This means when everything is well,
75  * we don't even have to jump over them.  Further, they do not intrude
76  * on our cache or tlb entries.
77  */
78
79 struct exception_table_entry {
80         unsigned long insn, fixup;
81 };
82
83 /*
84  * These are the main single-value transfer routines.  They automatically
85  * use the right size if we just have the right pointer type.
86  */
87
88 #define put_user(x,p)                                           \
89         ({                                                      \
90                 int _err = 0;                                   \
91                 typeof(*(p)) _x = (x);                          \
92                 typeof(*(p)) *_p = (p);                         \
93                 if (!access_ok(VERIFY_WRITE, _p, sizeof(*(_p)))) {\
94                         _err = -EFAULT;                         \
95                 }                                               \
96                 else {                                          \
97                 switch (sizeof (*(_p))) {                       \
98                 case 1:                                         \
99                         __put_user_asm(_x, _p, B);              \
100                         break;                                  \
101                 case 2:                                         \
102                         __put_user_asm(_x, _p, W);              \
103                         break;                                  \
104                 case 4:                                         \
105                         __put_user_asm(_x, _p,  );              \
106                         break;                                  \
107                 case 8: {                                       \
108                         long _xl, _xh;                          \
109                         _xl = ((long *)&_x)[0];                 \
110                         _xh = ((long *)&_x)[1];                 \
111                         __put_user_asm(_xl, ((long *)_p)+0, );  \
112                         __put_user_asm(_xh, ((long *)_p)+1, );  \
113                 } break;                                        \
114                 default:                                        \
115                         _err = __put_user_bad();                \
116                         break;                                  \
117                 }                                               \
118                 }                                               \
119                 _err;                                           \
120         })
121
122 #define __put_user(x,p) put_user(x,p)
123 static inline int bad_user_access_length(void)
124 {
125         panic("bad_user_access_length");
126         return -1;
127 }
128
129 #define __put_user_bad() (printk(KERN_INFO "put_user_bad %s:%d %s\n",\
130                            __FILE__, __LINE__, __func__),\
131                            bad_user_access_length(), (-EFAULT))
132
133 /*
134  * Tell gcc we read from memory instead of writing: this is because
135  * we do not write to any memory gcc knows about, so there are no
136  * aliasing issues.
137  */
138
139 #define __ptr(x) ((unsigned long *)(x))
140
141 #define __put_user_asm(x,p,bhw)                         \
142         __asm__ (#bhw"[%1] = %0;\n\t"                   \
143                  : /* no outputs */                     \
144                  :"d" (x),"a" (__ptr(p)) : "memory")
145
146 #define get_user(x, ptr)                                        \
147 ({                                                              \
148         int _err = 0;                                           \
149         unsigned long _val = 0;                                 \
150         const typeof(*(ptr)) __user *_p = (ptr);                \
151         const size_t ptr_size = sizeof(*(_p));                  \
152         if (likely(access_ok(VERIFY_READ, _p, ptr_size))) {     \
153                 BUILD_BUG_ON(ptr_size >= 8);                    \
154                 switch (ptr_size) {                             \
155                 case 1:                                         \
156                         __get_user_asm(_val, _p, B,(Z));        \
157                         break;                                  \
158                 case 2:                                         \
159                         __get_user_asm(_val, _p, W,(Z));        \
160                         break;                                  \
161                 case 4:                                         \
162                         __get_user_asm(_val, _p,  , );          \
163                         break;                                  \
164                 }                                               \
165         } else                                                  \
166                 _err = -EFAULT;                                 \
167         x = (typeof(*(ptr)))_val;                               \
168         _err;                                                   \
169 })
170
171 #define __get_user(x,p) get_user(x,p)
172
173 #define __get_user_bad() (bad_user_access_length(), (-EFAULT))
174
175 #define __get_user_asm(x, ptr, bhw, option)     \
176 ({                                              \
177         __asm__ __volatile__ (                  \
178                 "%0 =" #bhw "[%1]" #option ";"  \
179                 : "=d" (x)                      \
180                 : "a" (__ptr(ptr)));            \
181 })
182
183 #define __copy_from_user(to, from, n) copy_from_user(to, from, n)
184 #define __copy_to_user(to, from, n) copy_to_user(to, from, n)
185 #define __copy_to_user_inatomic __copy_to_user
186 #define __copy_from_user_inatomic __copy_from_user
187
188 #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n))\
189                                                  return retval; })
190
191 #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n))\
192                                                    return retval; })
193
194 static inline unsigned long __must_check
195 copy_from_user(void *to, const void __user *from, unsigned long n)
196 {
197         if (access_ok(VERIFY_READ, from, n))
198                 memcpy(to, from, n);
199         else
200                 return n;
201         return 0;
202 }
203
204 static inline unsigned long __must_check
205 copy_to_user(void *to, const void __user *from, unsigned long n)
206 {
207         if (access_ok(VERIFY_WRITE, to, n))
208                 memcpy(to, from, n);
209         else
210                 return n;
211         return 0;
212 }
213
214 /*
215  * Copy a null terminated string from userspace.
216  */
217
218 static inline long __must_check
219 strncpy_from_user(char *dst, const char *src, long count)
220 {
221         char *tmp;
222         if (!access_ok(VERIFY_READ, src, 1))
223                 return -EFAULT;
224         strncpy(dst, src, count);
225         for (tmp = dst; *tmp && count > 0; tmp++, count--) ;
226         return (tmp - dst);
227 }
228
229 /*
230  * Get the size of a string in user space.
231  *   src: The string to measure
232  *     n: The maximum valid length
233  *
234  * Get the size of a NUL-terminated string in user space.
235  *
236  * Returns the size of the string INCLUDING the terminating NUL.
237  * On exception, returns 0.
238  * If the string is too long, returns a value greater than n.
239  */
240 static inline long __must_check strnlen_user(const char *src, long n)
241 {
242         if (!access_ok(VERIFY_READ, src, 1))
243                 return 0;
244         return strnlen(src, n) + 1;
245 }
246
247 static inline long __must_check strlen_user(const char *src)
248 {
249         if (!access_ok(VERIFY_READ, src, 1))
250                 return 0;
251         return strlen(src) + 1;
252 }
253
254 /*
255  * Zero Userspace
256  */
257
258 static inline unsigned long __must_check
259 __clear_user(void *to, unsigned long n)
260 {
261         if (!access_ok(VERIFY_WRITE, to, n))
262                 return n;
263         memset(to, 0, n);
264         return 0;
265 }
266
267 #define clear_user(to, n) __clear_user(to, n)
268
269 /* How to interpret these return values:
270  *      CORE:      can be accessed by core load or dma memcpy
271  *      CORE_ONLY: can only be accessed by core load
272  *      DMA:       can only be accessed by dma memcpy
273  *      IDMA:      can only be accessed by interprocessor dma memcpy (BF561)
274  *      ITEST:     can be accessed by isram memcpy or dma memcpy
275  */
276 enum {
277         BFIN_MEM_ACCESS_CORE = 0,
278         BFIN_MEM_ACCESS_CORE_ONLY,
279         BFIN_MEM_ACCESS_DMA,
280         BFIN_MEM_ACCESS_IDMA,
281         BFIN_MEM_ACCESS_ITEST,
282 };
283 /**
284  *      bfin_mem_access_type() - what kind of memory access is required
285  *      @addr:   the address to check
286  *      @size:   number of bytes needed
287  *      @return: <0 is error, >=0 is BFIN_MEM_ACCESS_xxx enum (see above)
288  */
289 int bfin_mem_access_type(unsigned long addr, unsigned long size);
290
291 #endif                          /* _BLACKFIN_UACCESS_H */