1 /* Changes made by Lineo Inc. May 2001
2 *
3 * Based on: include/asm-m68knommu/uaccess.h
4 */
5
6 #ifndef __BLACKFIN_UACCESS_H
7 #define __BLACKFIN_UACCESS_H
8
9 /*
10 * User space memory access functions
11 */
12 #include <linux/sched.h>
13 #include <linux/mm.h>
14 #include <linux/string.h>
15
16 #include <asm/segment.h>
17 #ifdef CONFIG_ACCESS_CHECK
18 # include <asm/bfin-global.h>
19 #endif
20
21 #define get_ds() (KERNEL_DS)
22 #define get_fs() (current_thread_info()->addr_limit)
23
set_fs(mm_segment_t fs)24 static inline void set_fs(mm_segment_t fs)
25 {
26 current_thread_info()->addr_limit = fs;
27 }
28
29 #define segment_eq(a,b) ((a) == (b))
30
31 #define VERIFY_READ 0
32 #define VERIFY_WRITE 1
33
34 #define access_ok(type, addr, size) _access_ok((unsigned long)(addr), (size))
35
is_in_rom(unsigned long addr)36 static inline int is_in_rom(unsigned long addr)
37 {
38 /*
39 * What we are really trying to do is determine if addr is
40 * in an allocated kernel memory region. If not then assume
41 * we cannot free it or otherwise de-allocate it. Ideally
42 * we could restrict this to really being in a ROM or flash,
43 * but that would need to be done on a board by board basis,
44 * not globally.
45 */
46 if ((addr < _ramstart) || (addr >= _ramend))
47 return (1);
48
49 /* Default case, not in ROM */
50 return (0);
51 }
52
53 /*
54 * The fs value determines whether argument validity checking should be
55 * performed or not. If get_fs() == USER_DS, checking is performed, with
56 * get_fs() == KERNEL_DS, checking is bypassed.
57 */
58
59 #ifndef CONFIG_ACCESS_CHECK
_access_ok(unsigned long addr,unsigned long size)60 static inline int _access_ok(unsigned long addr, unsigned long size) { return 1; }
61 #else
62 #ifdef CONFIG_ACCESS_OK_L1
63 extern int _access_ok(unsigned long addr, unsigned long size)__attribute__((l1_text));
64 #else
65 extern int _access_ok(unsigned long addr, unsigned long size);
66 #endif
67 #endif
68
69 /*
70 * The exception table consists of pairs of addresses: the first is the
71 * address of an instruction that is allowed to fault, and the second is
72 * the address at which the program should continue. No registers are
73 * modified, so it is entirely up to the continuation code to figure out
74 * what to do.
75 *
76 * All the routines below use bits of fixup code that are out of line
77 * with the main instruction path. This means when everything is well,
78 * we don't even have to jump over them. Further, they do not intrude
79 * on our cache or tlb entries.
80 */
81
82 struct exception_table_entry {
83 unsigned long insn, fixup;
84 };
85
86 /* Returns 0 if exception not found and fixup otherwise. */
87 extern unsigned long search_exception_table(unsigned long);
88
89 /*
90 * These are the main single-value transfer routines. They automatically
91 * use the right size if we just have the right pointer type.
92 */
93
94 #define put_user(x,p) \
95 ({ \
96 int _err = 0; \
97 typeof(*(p)) _x = (x); \
98 typeof(*(p)) *_p = (p); \
99 if (!access_ok(VERIFY_WRITE, _p, sizeof(*(_p)))) {\
100 _err = -EFAULT; \
101 } \
102 else { \
103 switch (sizeof (*(_p))) { \
104 case 1: \
105 __put_user_asm(_x, _p, B); \
106 break; \
107 case 2: \
108 __put_user_asm(_x, _p, W); \
109 break; \
110 case 4: \
111 __put_user_asm(_x, _p, ); \
112 break; \
113 case 8: { \
114 long _xl, _xh; \
115 _xl = ((long *)&_x)[0]; \
116 _xh = ((long *)&_x)[1]; \
117 __put_user_asm(_xl, ((long *)_p)+0, ); \
118 __put_user_asm(_xh, ((long *)_p)+1, ); \
119 } break; \
120 default: \
121 _err = __put_user_bad(); \
122 break; \
123 } \
124 } \
125 _err; \
126 })
127
128 #define __put_user(x,p) put_user(x,p)
bad_user_access_length(void)129 static inline int bad_user_access_length(void)
130 {
131 panic("bad_user_access_length");
132 return -1;
133 }
134
135 #define __put_user_bad() (printk(KERN_INFO "put_user_bad %s:%d %s\n",\
136 __FILE__, __LINE__, __func__),\
137 bad_user_access_length(), (-EFAULT))
138
139 /*
140 * Tell gcc we read from memory instead of writing: this is because
141 * we do not write to any memory gcc knows about, so there are no
142 * aliasing issues.
143 */
144
145 #define __ptr(x) ((unsigned long *)(x))
146
147 #define __put_user_asm(x,p,bhw) \
148 __asm__ (#bhw"[%1] = %0;\n\t" \
149 : /* no outputs */ \
150 :"d" (x),"a" (__ptr(p)) : "memory")
151
152 #define get_user(x, ptr) \
153 ({ \
154 int _err = 0; \
155 unsigned long _val = 0; \
156 const typeof(*(ptr)) __user *_p = (ptr); \
157 const size_t ptr_size = sizeof(*(_p)); \
158 if (likely(access_ok(VERIFY_READ, _p, ptr_size))) { \
159 BUILD_BUG_ON(ptr_size >= 8); \
160 switch (ptr_size) { \
161 case 1: \
162 __get_user_asm(_val, _p, B,(Z)); \
163 break; \
164 case 2: \
165 __get_user_asm(_val, _p, W,(Z)); \
166 break; \
167 case 4: \
168 __get_user_asm(_val, _p, , ); \
169 break; \
170 } \
171 } else \
172 _err = -EFAULT; \
173 x = (typeof(*(ptr)))_val; \
174 _err; \
175 })
176
177 #define __get_user(x,p) get_user(x,p)
178
179 #define __get_user_bad() (bad_user_access_length(), (-EFAULT))
180
181 #define __get_user_asm(x, ptr, bhw, option) \
182 ({ \
183 __asm__ __volatile__ ( \
184 "%0 =" #bhw "[%1]" #option ";" \
185 : "=d" (x) \
186 : "a" (__ptr(ptr))); \
187 })
188
189 #define __copy_from_user(to, from, n) copy_from_user(to, from, n)
190 #define __copy_to_user(to, from, n) copy_to_user(to, from, n)
191 #define __copy_to_user_inatomic __copy_to_user
192 #define __copy_from_user_inatomic __copy_from_user
193
194 #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n))\
195 return retval; })
196
197 #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n))\
198 return retval; })
199
200 static inline unsigned long __must_check
copy_from_user(void * to,const void __user * from,unsigned long n)201 copy_from_user(void *to, const void __user *from, unsigned long n)
202 {
203 if (access_ok(VERIFY_READ, from, n))
204 memcpy(to, from, n);
205 else
206 return n;
207 return 0;
208 }
209
210 static inline unsigned long __must_check
copy_to_user(void * to,const void __user * from,unsigned long n)211 copy_to_user(void *to, const void __user *from, unsigned long n)
212 {
213 if (access_ok(VERIFY_WRITE, to, n))
214 memcpy(to, from, n);
215 else
216 return n;
217 return 0;
218 }
219
220 /*
221 * Copy a null terminated string from userspace.
222 */
223
224 static inline long __must_check
strncpy_from_user(char * dst,const char * src,long count)225 strncpy_from_user(char *dst, const char *src, long count)
226 {
227 char *tmp;
228 if (!access_ok(VERIFY_READ, src, 1))
229 return -EFAULT;
230 strncpy(dst, src, count);
231 for (tmp = dst; *tmp && count > 0; tmp++, count--) ;
232 return (tmp - dst);
233 }
234
235 /*
236 * Return the size of a string (including the ending 0)
237 *
238 * Return 0 on exception, a value greater than N if too long
239 */
strnlen_user(const char * src,long n)240 static inline long strnlen_user(const char *src, long n)
241 {
242 return (strlen(src) + 1);
243 }
244
245 #define strlen_user(str) strnlen_user(str, 32767)
246
247 /*
248 * Zero Userspace
249 */
250
251 static inline unsigned long __must_check
__clear_user(void * to,unsigned long n)252 __clear_user(void *to, unsigned long n)
253 {
254 memset(to, 0, n);
255 return 0;
256 }
257
258 #define clear_user(to, n) __clear_user(to, n)
259
260 #endif /* _BLACKFIN_UACCESS_H */
261