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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
18static inline int _access_ok(unsigned long addr, unsigned long size)
19{
20 extern unsigned long memory_start, memory_end;
21
22 return (((addr >= memory_start) && (addr+size < memory_end)) ||
23 (is_in_rom(addr) && is_in_rom(addr+size)));
24}
25
Linus Torvalds1da177e2005-04-16 15:20:36 -070026/*
27 * The exception table consists of pairs of addresses: the first is the
28 * address of an instruction that is allowed to fault, and the second is
29 * the address at which the program should continue. No registers are
30 * modified, so it is entirely up to the continuation code to figure out
31 * what to do.
32 *
33 * All the routines below use bits of fixup code that are out of line
34 * with the main instruction path. This means when everything is well,
35 * we don't even have to jump over them. Further, they do not intrude
36 * on our cache or tlb entries.
37 */
38
39struct exception_table_entry
40{
41 unsigned long insn, fixup;
42};
43
44/* Returns 0 if exception not found and fixup otherwise. */
45extern unsigned long search_exception_table(unsigned long);
46
47
48/*
49 * These are the main single-value transfer routines. They automatically
50 * use the right size if we just have the right pointer type.
51 */
52
53#define put_user(x, ptr) \
54({ \
55 int __pu_err = 0; \
56 typeof(*(ptr)) __pu_val = (x); \
57 switch (sizeof (*(ptr))) { \
58 case 1: \
59 __put_user_asm(__pu_err, __pu_val, ptr, b); \
60 break; \
61 case 2: \
62 __put_user_asm(__pu_err, __pu_val, ptr, w); \
63 break; \
64 case 4: \
65 __put_user_asm(__pu_err, __pu_val, ptr, l); \
66 break; \
67 case 8: \
68 memcpy(ptr, &__pu_val, sizeof (*(ptr))); \
69 break; \
70 default: \
71 __pu_err = __put_user_bad(); \
72 break; \
73 } \
74 __pu_err; \
75})
76#define __put_user(x, ptr) put_user(x, ptr)
77
78extern int __put_user_bad(void);
79
80/*
81 * Tell gcc we read from memory instead of writing: this is because
82 * we do not write to any memory gcc knows about, so there are no
83 * aliasing issues.
84 */
85
86#define __ptr(x) ((unsigned long *)(x))
87
88#define __put_user_asm(err,x,ptr,bwl) \
89 __asm__ ("move" #bwl " %0,%1" \
90 : /* no outputs */ \
91 :"d" (x),"m" (*__ptr(ptr)) : "memory")
92
93#define get_user(x, ptr) \
94({ \
95 int __gu_err = 0; \
96 typeof(*(ptr)) __gu_val = 0; \
97 switch (sizeof(*(ptr))) { \
98 case 1: \
99 __get_user_asm(__gu_err, __gu_val, ptr, b, "=d"); \
100 break; \
101 case 2: \
102 __get_user_asm(__gu_err, __gu_val, ptr, w, "=r"); \
103 break; \
104 case 4: \
105 __get_user_asm(__gu_err, __gu_val, ptr, l, "=r"); \
106 break; \
107 case 8: \
108 memcpy(&__gu_val, ptr, sizeof (*(ptr))); \
109 break; \
110 default: \
111 __gu_val = 0; \
112 __gu_err = __get_user_bad(); \
113 break; \
114 } \
115 (x) = __gu_val; \
116 __gu_err; \
117})
118#define __get_user(x, ptr) get_user(x, ptr)
119
120extern int __get_user_bad(void);
121
122#define __get_user_asm(err,x,ptr,bwl,reg) \
123 __asm__ ("move" #bwl " %1,%0" \
124 : "=d" (x) \
125 : "m" (*__ptr(ptr)))
126
127#define copy_from_user(to, from, n) (memcpy(to, from, n), 0)
128#define copy_to_user(to, from, n) (memcpy(to, from, n), 0)
129
130#define __copy_from_user(to, from, n) copy_from_user(to, from, n)
131#define __copy_to_user(to, from, n) copy_to_user(to, from, n)
132#define __copy_to_user_inatomic __copy_to_user
133#define __copy_from_user_inatomic __copy_from_user
134
135#define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
136
137#define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
138
139/*
140 * Copy a null terminated string from userspace.
141 */
142
143static inline long
144strncpy_from_user(char *dst, const char *src, long count)
145{
146 char *tmp;
147 strncpy(dst, src, count);
148 for (tmp = dst; *tmp && count > 0; tmp++, count--)
149 ;
150 return(tmp - dst); /* DAVIDM should we count a NUL ? check getname */
151}
152
153/*
154 * Return the size of a string (including the ending 0)
155 *
156 * Return 0 on exception, a value greater than N if too long
157 */
158static inline long strnlen_user(const char *src, long n)
159{
160 return(strlen(src) + 1); /* DAVIDM make safer */
161}
162
163#define strlen_user(str) strnlen_user(str, 32767)
164
165/*
166 * Zero Userspace
167 */
168
169static inline unsigned long
170clear_user(void *to, unsigned long n)
171{
172 memset(to, 0, n);
173 return 0;
174}
175
176#endif /* _M68KNOMMU_UACCESS_H */