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
22 /*
23 * Segment stuff
24 */
25 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
26 #define USER_DS MAKE_MM_SEG(0x80000000UL)
27 #define KERNEL_DS MAKE_MM_SEG(0)
28
29
30 #define get_fs() (current_thread_info()->addr_limit)
31 #define set_fs(seg) (current_thread_info()->addr_limit = (seg))
32
33 #define segment_eq(a, b) ((a).seg == (b).seg)
34
35 #define __access_ok(addr, len) \
36 (((signed long)(((long)get_fs().seg) & \
37 ((long)(addr) | (((long)(addr)) + (len)) | (len)))) == 0)
38
39 #define access_ok(addr, len) \
40 likely(__access_ok((unsigned long)(addr), (unsigned long)(len)))
41
42 # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n"
43
44 #define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE)
45
46 /*
47 * Zero Userspace
48 */
49
50 static inline unsigned long __must_check __clear_user(void __user *to,
51 unsigned long n)
52 {
53 __asm__ __volatile__ (
54 "1: stb zero, 0(%1)\n"
55 " addi %0, %0, -1\n"
56 " addi %1, %1, 1\n"
57 " bne %0, zero, 1b\n"
58 "2:\n"
59 __EX_TABLE_SECTION
60 ".word 1b, 2b\n"
61 ".previous\n"
62 : "=r" (n), "=r" (to)
63 : "0" (n), "1" (to)
64 );
65
66 return n;
67 }
68
69 static inline unsigned long __must_check clear_user(void __user *to,
70 unsigned long n)
71 {
72 if (!access_ok(to, n))
73 return n;
74 return __clear_user(to, n);
75 }
76
77 extern unsigned long
78 raw_copy_from_user(void *to, const void __user *from, unsigned long n);
79 extern unsigned long
80 raw_copy_to_user(void __user *to, const void *from, unsigned long n);
81 #define INLINE_COPY_FROM_USER
82 #define INLINE_COPY_TO_USER
83
84 extern long strncpy_from_user(char *__to, const char __user *__from,
85 long __len);
86 extern __must_check long strlen_user(const char __user *str);
87 extern __must_check long strnlen_user(const char __user *s, long n);
88
89 /* Optimized macros */
90 #define __get_user_asm(val, insn, addr, err) \
91 { \
92 __asm__ __volatile__( \
93 " movi %0, %3\n" \
94 "1: " insn " %1, 0(%2)\n" \
95 " movi %0, 0\n" \
96 "2:\n" \
97 " .section __ex_table,\"a\"\n" \
98 " .word 1b, 2b\n" \
99 " .previous" \
100 : "=&r" (err), "=r" (val) \
101 : "r" (addr), "i" (-EFAULT)); \
102 }
103
104 #define __get_user_unknown(val, size, ptr, err) do { \
105 err = 0; \
106 if (__copy_from_user(&(val), ptr, size)) { \
107 err = -EFAULT; \
108 } \
109 } while (0)
110
111 #define __get_user_common(val, size, ptr, err) \
112 do { \
113 switch (size) { \
114 case 1: \
115 __get_user_asm(val, "ldbu", ptr, err); \
116 break; \
117 case 2: \
118 __get_user_asm(val, "ldhu", ptr, err); \
119 break; \
120 case 4: \
121 __get_user_asm(val, "ldw", ptr, err); \
122 break; \
123 default: \
124 __get_user_unknown(val, size, ptr, err); \
125 break; \
126 } \
127 } while (0)
128
129 #define __get_user(x, ptr) \
130 ({ \
131 long __gu_err = -EFAULT; \
132 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
133 unsigned long __gu_val = 0; \
134 __get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\
135 (x) = (__force __typeof__(x))__gu_val; \
136 __gu_err; \
137 })
138
139 #define get_user(x, ptr) \
140 ({ \
141 long __gu_err = -EFAULT; \
142 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
143 unsigned long __gu_val = 0; \
144 if (access_ok( __gu_ptr, sizeof(*__gu_ptr))) \
145 __get_user_common(__gu_val, sizeof(*__gu_ptr), \
146 __gu_ptr, __gu_err); \
147 (x) = (__force __typeof__(x))__gu_val; \
148 __gu_err; \
149 })
150
151 #define __put_user_asm(val, insn, ptr, err) \
152 { \
153 __asm__ __volatile__( \
154 " movi %0, %3\n" \
155 "1: " insn " %1, 0(%2)\n" \
156 " movi %0, 0\n" \
157 "2:\n" \
158 " .section __ex_table,\"a\"\n" \
159 " .word 1b, 2b\n" \
160 " .previous\n" \
161 : "=&r" (err) \
162 : "r" (val), "r" (ptr), "i" (-EFAULT)); \
163 }
164
165 #define put_user(x, ptr) \
166 ({ \
167 long __pu_err = -EFAULT; \
168 __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
169 __typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \
170 if (access_ok(__pu_ptr, sizeof(*__pu_ptr))) { \
171 switch (sizeof(*__pu_ptr)) { \
172 case 1: \
173 __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
174 break; \
175 case 2: \
176 __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
177 break; \
178 case 4: \
179 __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
180 break; \
181 default: \
182 /* XXX: This looks wrong... */ \
183 __pu_err = 0; \
184 if (copy_to_user(__pu_ptr, &(__pu_val), \
185 sizeof(*__pu_ptr))) \
186 __pu_err = -EFAULT; \
187 break; \
188 } \
189 } \
190 __pu_err; \
191 })
192
193 #define __put_user(x, ptr) put_user(x, ptr)
194
195 #endif /* _ASM_NIOS2_UACCESS_H */