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
set_fs(mm_segment_t fs)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
is_in_rom(unsigned long addr)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
_access_ok(unsigned long addr,unsigned long size)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)
bad_user_access_length(void)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
copy_from_user(void * to,const void __user * from,unsigned long n)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, (const void __force *)from, n);
199 else
200 return n;
201 return 0;
202 }
203
204 static inline unsigned long __must_check
copy_to_user(void __user * to,const void * from,unsigned long n)205 copy_to_user(void __user *to, const void *from, unsigned long n)
206 {
207 if (access_ok(VERIFY_WRITE, to, n))
208 memcpy((void __force *)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
strncpy_from_user(char * dst,const char * src,long count)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 */
strnlen_user(const char * src,long n)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
strlen_user(const char * src)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
__clear_user(void * to,unsigned long n)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 */
292