1 /*
2 * User space memory access functions for Nios II
3 *
4 * Copyright (C) 2010-2011, Tobias Klauser <tklauser@distanz.ch>
5 * Copyright (C) 2009, Wind River Systems Inc
6 * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12
13 #ifndef _ASM_NIOS2_UACCESS_H
14 #define _ASM_NIOS2_UACCESS_H
15
16 #include <linux/string.h>
17
18 #include <asm/page.h>
19
20 #include <asm/extable.h>
21 #include <asm-generic/access_ok.h>
22
23 # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n"
24
25 /*
26 * Zero Userspace
27 */
28
29 static inline unsigned long __must_check __clear_user(void __user *to,
30 unsigned long n)
31 {
32 __asm__ __volatile__ (
33 "1: stb zero, 0(%1)\n"
34 " addi %0, %0, -1\n"
35 " addi %1, %1, 1\n"
36 " bne %0, zero, 1b\n"
37 "2:\n"
38 __EX_TABLE_SECTION
39 ".word 1b, 2b\n"
40 ".previous\n"
41 : "=r" (n), "=r" (to)
42 : "" (n), "1" (to)
43 );
44
45 return n;
46 }
47
48 static inline unsigned long __must_check clear_user(void __user *to,
49 unsigned long n)
50 {
51 if (!access_ok(to, n))
52 return n;
53 return __clear_user(to, n);
54 }
55
56 extern unsigned long
57 raw_copy_from_user(void *to, const void __user *from, unsigned long n);
58 extern unsigned long
59 raw_copy_to_user(void __user *to, const void *from, unsigned long n);
60 #define INLINE_COPY_FROM_USER
61 #define INLINE_COPY_TO_USER
62
63 extern long strncpy_from_user(char *__to, const char __user *__from,
64 long __len);
65 extern __must_check long strnlen_user(const char __user *s, long n);
66
67 /* Optimized macros */
68 #define __get_user_asm(val, insn, addr, err) \
69 { \
70 unsigned long __gu_val; \
71 __asm__ __volatile__( \
72 " movi %0, %3\n" \
73 "1: " insn " %1, 0(%2)\n" \
74 " movi %0, 0\n" \
75 "2:\n" \
76 " .section __ex_table,\"a\"\n" \
77 " .word 1b, 2b\n" \
78 " .previous" \
79 : "=&r" (err), "=r" (__gu_val) \
80 : "r" (addr), "i" (-EFAULT)); \
81 val = (__force __typeof__(*(addr)))__gu_val; \
82 }
83
84 extern void __get_user_unknown(void);
85
86 #define __get_user_8(val, ptr, err) do { \
87 u64 __val = 0; \
88 err = 0; \
89 if (raw_copy_from_user(&(__val), ptr, sizeof(val))) { \
90 err = -EFAULT; \
91 } else { \
92 val = (typeof(val))(typeof((val) - (val)))__val; \
93 } \
94 } while (0)
95
96 #define __get_user_common(val, size, ptr, err) \
97 do { \
98 switch (size) { \
99 case 1: \
100 __get_user_asm(val, "ldbu", ptr, err); \
101 break; \
102 case 2: \
103 __get_user_asm(val, "ldhu", ptr, err); \
104 break; \
105 case 4: \
106 __get_user_asm(val, "ldw", ptr, err); \
107 break; \
108 case 8: \
109 __get_user_8(val, ptr, err); \
110 break; \
111 default: \
112 __get_user_unknown(); \
113 break; \
114 } \
115 } while (0)
116
117 #define __get_user(x, ptr) \
118 ({ \
119 long __gu_err = -EFAULT; \
120 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
121 __get_user_common(x, sizeof(*(ptr)), __gu_ptr, __gu_err); \
122 __gu_err; \
123 })
124
125 #define get_user(x, ptr) \
126 ({ \
127 long __gu_err = -EFAULT; \
128 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
129 if (access_ok( __gu_ptr, sizeof(*__gu_ptr))) \
130 __get_user_common(x, sizeof(*__gu_ptr), \
131 __gu_ptr, __gu_err); \
132 __gu_err; \
133 })
134
135 #define __put_user_asm(val, insn, ptr, err) \
136 { \
137 __asm__ __volatile__( \
138 " movi %0, %3\n" \
139 "1: " insn " %1, 0(%2)\n" \
140 " movi %0, 0\n" \
141 "2:\n" \
142 " .section __ex_table,\"a\"\n" \
143 " .word 1b, 2b\n" \
144 " .previous\n" \
145 : "=&r" (err) \
146 : "r" (val), "r" (ptr), "i" (-EFAULT)); \
147 }
148
149 #define __put_user_common(__pu_val, __pu_ptr) \
150 ({ \
151 long __pu_err = -EFAULT; \
152 switch (sizeof(*__pu_ptr)) { \
153 case 1: \
154 __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
155 break; \
156 case 2: \
157 __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
158 break; \
159 case 4: \
160 __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
161 break; \
162 default: \
163 /* XXX: This looks wrong... */ \
164 __pu_err = 0; \
165 if (__copy_to_user(__pu_ptr, &(__pu_val), \
166 sizeof(*__pu_ptr))) \
167 __pu_err = -EFAULT; \
168 break; \
169 } \
170 __pu_err; \
171 })
172
173 #define __put_user(x, ptr) \
174 ({ \
175 __auto_type __pu_ptr = (ptr); \
176 typeof(*__pu_ptr) __pu_val = (typeof(*__pu_ptr))(x); \
177 __put_user_common(__pu_val, __pu_ptr); \
178 })
179
180 #define put_user(x, ptr) \
181 ({ \
182 __auto_type __pu_ptr = (ptr); \
183 typeof(*__pu_ptr) __pu_val = (typeof(*__pu_ptr))(x); \
184 access_ok(__pu_ptr, sizeof(*__pu_ptr)) ? \
185 __put_user_common(__pu_val, __pu_ptr) : \
186 -EFAULT; \
187 })
188
189 #endif /* _ASM_NIOS2_UACCESS_H */
190
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