1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __M68KNOMMU_UACCESS_H
3 #define __M68KNOMMU_UACCESS_H
4
5 /*
6 * User space memory access functions
7 */
8 #include <linux/mm.h>
9 #include <linux/string.h>
10
11 #include <asm/segment.h>
12
13 #define access_ok(addr,size) _access_ok((unsigned long)(addr),(size))
14
15 /*
16 * It is not enough to just have access_ok check for a real RAM address.
17 * This would disallow the case of code/ro-data running XIP in flash/rom.
18 * Ideally we would check the possible flash ranges too, but that is
19 * currently not so easy.
20 */
21 static inline int _access_ok(unsigned long addr, unsigned long size)
22 {
23 return 1;
24 }
25
26 /*
27 * These are the main single-value transfer routines. They automatically
28 * use the right size if we just have the right pointer type.
29 */
30
31 #define put_user(x, ptr) \
32 ({ \
33 int __pu_err = 0; \
34 typeof(*(ptr)) __pu_val = (x); \
35 switch (sizeof (*(ptr))) { \
36 case 1: \
37 __put_user_asm(__pu_err, __pu_val, ptr, b); \
38 break; \
39 case 2: \
40 __put_user_asm(__pu_err, __pu_val, ptr, w); \
41 break; \
42 case 4: \
43 __put_user_asm(__pu_err, __pu_val, ptr, l); \
44 break; \
45 case 8: \
46 memcpy(ptr, &__pu_val, sizeof (*(ptr))); \
47 break; \
48 default: \
49 __pu_err = __put_user_bad(); \
50 break; \
51 } \
52 __pu_err; \
53 })
54 #define __put_user(x, ptr) put_user(x, ptr)
55
56 extern int __put_user_bad(void);
57
58 /*
59 * Tell gcc we read from memory instead of writing: this is because
60 * we do not write to any memory gcc knows about, so there are no
61 * aliasing issues.
62 */
63
64 #define __ptr(x) ((unsigned long *)(x))
65
66 #define __put_user_asm(err,x,ptr,bwl) \
67 __asm__ ("move" #bwl " %0,%1" \
68 : /* no outputs */ \
69 :"d" (x),"m" (*__ptr(ptr)) : "memory")
70
71 #define get_user(x, ptr) \
72 ({ \
73 int __gu_err = 0; \
74 typeof(x) __gu_val = 0; \
75 switch (sizeof(*(ptr))) { \
76 case 1: \
77 __get_user_asm(__gu_err, __gu_val, ptr, b, "=d"); \
78 break; \
79 case 2: \
80 __get_user_asm(__gu_err, __gu_val, ptr, w, "=r"); \
81 break; \
82 case 4: \
83 __get_user_asm(__gu_err, __gu_val, ptr, l, "=r"); \
84 break; \
85 case 8: \
86 memcpy((void *) &__gu_val, ptr, sizeof (*(ptr))); \
87 break; \
88 default: \
89 __gu_val = 0; \
90 __gu_err = __get_user_bad(); \
91 break; \
92 } \
93 (x) = (typeof(*(ptr))) __gu_val; \
94 __gu_err; \
95 })
96 #define __get_user(x, ptr) get_user(x, ptr)
97
98 extern int __get_user_bad(void);
99
100 #define __get_user_asm(err,x,ptr,bwl,reg) \
101 __asm__ ("move" #bwl " %1,%0" \
102 : "=d" (x) \
103 : "m" (*__ptr(ptr)))
104
105 static inline unsigned long
106 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
107 {
108 memcpy(to, (__force const void *)from, n);
109 return 0;
110 }
111
112 static inline unsigned long
113 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
114 {
115 memcpy((__force void *)to, from, n);
116 return 0;
117 }
118 #define INLINE_COPY_FROM_USER
119 #define INLINE_COPY_TO_USER
120
121 /*
122 * Copy a null terminated string from userspace.
123 */
124
125 static inline long
126 strncpy_from_user(char *dst, const char *src, long count)
127 {
128 char *tmp;
129 strncpy(dst, src, count);
130 for (tmp = dst; *tmp && count > 0; tmp++, count--)
131 ;
132 return(tmp - dst); /* DAVIDM should we count a NUL ? check getname */
133 }
134
135 /*
136 * Return the size of a string (including the ending 0)
137 *
138 * Return 0 on exception, a value greater than N if too long
139 */
140 static inline long strnlen_user(const char *src, long n)
141 {
142 return(strlen(src) + 1); /* DAVIDM make safer */
143 }
144
145 /*
146 * Zero Userspace
147 */
148
149 static inline unsigned long
150 __clear_user(void *to, unsigned long n)
151 {
152 memset(to, 0, n);
153 return 0;
154 }
155
156 #define clear_user(to,n) __clear_user(to,n)
157
158 #endif /* _M68KNOMMU_UACCESS_H */