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