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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef __M68KNOMMU_UACCESS_H
2#define __M68KNOMMU_UACCESS_H
3
4/*
5 * User space memory access functions
6 */
7#include <linux/sched.h>
8#include <linux/mm.h>
9#include <linux/string.h>
10
11#include <asm/segment.h>
12
13#define VERIFY_READ 0
14#define VERIFY_WRITE 1
15
16#define access_ok(type,addr,size) _access_ok((unsigned long)(addr),(size))
17
Greg Ungerer10146802007-07-19 01:49:15 -070018/*
19 * It is not enough to just have access_ok check for a real RAM address.
20 * This would disallow the case of code/ro-data running XIP in flash/rom.
21 * Ideally we would check the possible flash ranges too, but that is
22 * currently not so easy.
23 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070024static inline int _access_ok(unsigned long addr, unsigned long size)
25{
Greg Ungerer10146802007-07-19 01:49:15 -070026 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070027}
28
Linus Torvalds1da177e2005-04-16 15:20:36 -070029/*
30 * The exception table consists of pairs of addresses: the first is the
31 * address of an instruction that is allowed to fault, and the second is
32 * the address at which the program should continue. No registers are
33 * modified, so it is entirely up to the continuation code to figure out
34 * what to do.
35 *
36 * All the routines below use bits of fixup code that are out of line
37 * with the main instruction path. This means when everything is well,
38 * we don't even have to jump over them. Further, they do not intrude
39 * on our cache or tlb entries.
40 */
41
42struct exception_table_entry
43{
44 unsigned long insn, fixup;
45};
46
47/* Returns 0 if exception not found and fixup otherwise. */
48extern unsigned long search_exception_table(unsigned long);
49
50
51/*
52 * These are the main single-value transfer routines. They automatically
53 * use the right size if we just have the right pointer type.
54 */
55
56#define put_user(x, ptr) \
57({ \
58 int __pu_err = 0; \
59 typeof(*(ptr)) __pu_val = (x); \
60 switch (sizeof (*(ptr))) { \
61 case 1: \
62 __put_user_asm(__pu_err, __pu_val, ptr, b); \
63 break; \
64 case 2: \
65 __put_user_asm(__pu_err, __pu_val, ptr, w); \
66 break; \
67 case 4: \
68 __put_user_asm(__pu_err, __pu_val, ptr, l); \
69 break; \
70 case 8: \
71 memcpy(ptr, &__pu_val, sizeof (*(ptr))); \
72 break; \
73 default: \
74 __pu_err = __put_user_bad(); \
75 break; \
76 } \
77 __pu_err; \
78})
79#define __put_user(x, ptr) put_user(x, ptr)
80
81extern int __put_user_bad(void);
82
83/*
84 * Tell gcc we read from memory instead of writing: this is because
85 * we do not write to any memory gcc knows about, so there are no
86 * aliasing issues.
87 */
88
89#define __ptr(x) ((unsigned long *)(x))
90
91#define __put_user_asm(err,x,ptr,bwl) \
92 __asm__ ("move" #bwl " %0,%1" \
93 : /* no outputs */ \
94 :"d" (x),"m" (*__ptr(ptr)) : "memory")
95
96#define get_user(x, ptr) \
97({ \
98 int __gu_err = 0; \
Greg Ungerer1b0f06d2006-07-13 09:32:41 +100099 typeof(x) __gu_val = 0; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 switch (sizeof(*(ptr))) { \
101 case 1: \
102 __get_user_asm(__gu_err, __gu_val, ptr, b, "=d"); \
103 break; \
104 case 2: \
105 __get_user_asm(__gu_err, __gu_val, ptr, w, "=r"); \
106 break; \
107 case 4: \
108 __get_user_asm(__gu_err, __gu_val, ptr, l, "=r"); \
109 break; \
110 case 8: \
Greg Ungerer1b0f06d2006-07-13 09:32:41 +1000111 memcpy((void *) &__gu_val, ptr, sizeof (*(ptr))); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 break; \
113 default: \
114 __gu_val = 0; \
115 __gu_err = __get_user_bad(); \
116 break; \
117 } \
Greg Ungerer1b0f06d2006-07-13 09:32:41 +1000118 (x) = (typeof(*(ptr))) __gu_val; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 __gu_err; \
120})
121#define __get_user(x, ptr) get_user(x, ptr)
122
123extern int __get_user_bad(void);
124
Greg Ungerer1b0f06d2006-07-13 09:32:41 +1000125#define __get_user_asm(err,x,ptr,bwl,reg) \
126 __asm__ ("move" #bwl " %1,%0" \
127 : "=d" (x) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 : "m" (*__ptr(ptr)))
129
130#define copy_from_user(to, from, n) (memcpy(to, from, n), 0)
131#define copy_to_user(to, from, n) (memcpy(to, from, n), 0)
132
133#define __copy_from_user(to, from, n) copy_from_user(to, from, n)
134#define __copy_to_user(to, from, n) copy_to_user(to, from, n)
135#define __copy_to_user_inatomic __copy_to_user
136#define __copy_from_user_inatomic __copy_from_user
137
138#define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
139
140#define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
141
142/*
143 * Copy a null terminated string from userspace.
144 */
145
146static inline long
147strncpy_from_user(char *dst, const char *src, long count)
148{
149 char *tmp;
150 strncpy(dst, src, count);
151 for (tmp = dst; *tmp && count > 0; tmp++, count--)
152 ;
153 return(tmp - dst); /* DAVIDM should we count a NUL ? check getname */
154}
155
156/*
157 * Return the size of a string (including the ending 0)
158 *
159 * Return 0 on exception, a value greater than N if too long
160 */
161static inline long strnlen_user(const char *src, long n)
162{
163 return(strlen(src) + 1); /* DAVIDM make safer */
164}
165
166#define strlen_user(str) strnlen_user(str, 32767)
167
168/*
169 * Zero Userspace
170 */
171
172static inline unsigned long
Matt Waddelfa2eae92007-10-23 14:37:54 +1000173__clear_user(void *to, unsigned long n)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174{
175 memset(to, 0, n);
176 return 0;
177}
178
Matt Waddelfa2eae92007-10-23 14:37:54 +1000179#define clear_user(to,n) __clear_user(to,n)
180
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181#endif /* _M68KNOMMU_UACCESS_H */