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 #define get_ds() (KERNEL_DS)
30
31 #define get_fs() (current_thread_info()->addr_limit)
32 #define set_fs(seg) (current_thread_info()->addr_limit = (seg))
33
34 #define segment_eq(a, b) ((a).seg == (b).seg)
35
36 #define __access_ok(addr, len) \
37 (((signed long)(((long)get_fs().seg) & \
38 ((long)(addr) | (((long)(addr)) + (len)) | (len)))) == 0)
39
40 #define access_ok(type, addr, len) \
41 likely(__access_ok((unsigned long)(addr), (unsigned long)(len)))
42
43 # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n"
44
45 #define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE)
46
47 /*
48 * Zero Userspace
49 */
50
__clear_user(void __user * to,unsigned long n)51 static inline unsigned long __must_check __clear_user(void __user *to,
52 unsigned long n)
53 {
54 __asm__ __volatile__ (
55 "1: stb zero, 0(%1)\n"
56 " addi %0, %0, -1\n"
57 " addi %1, %1, 1\n"
58 " bne %0, zero, 1b\n"
59 "2:\n"
60 __EX_TABLE_SECTION
61 ".word 1b, 2b\n"
62 ".previous\n"
63 : "=r" (n), "=r" (to)
64 : "0" (n), "1" (to)
65 );
66
67 return n;
68 }
69
clear_user(void __user * to,unsigned long n)70 static inline unsigned long __must_check clear_user(void __user *to,
71 unsigned long n)
72 {
73 if (!access_ok(VERIFY_WRITE, to, n))
74 return n;
75 return __clear_user(to, n);
76 }
77
78 extern unsigned long
79 raw_copy_from_user(void *to, const void __user *from, unsigned long n);
80 extern unsigned long
81 raw_copy_to_user(void __user *to, const void *from, unsigned long n);
82 #define INLINE_COPY_FROM_USER
83 #define INLINE_COPY_TO_USER
84
85 extern long strncpy_from_user(char *__to, const char __user *__from,
86 long __len);
87 extern __must_check long strlen_user(const char __user *str);
88 extern __must_check long strnlen_user(const char __user *s, long n);
89
90 /* Optimized macros */
91 #define __get_user_asm(val, insn, addr, err) \
92 { \
93 __asm__ __volatile__( \
94 " movi %0, %3\n" \
95 "1: " insn " %1, 0(%2)\n" \
96 " movi %0, 0\n" \
97 "2:\n" \
98 " .section __ex_table,\"a\"\n" \
99 " .word 1b, 2b\n" \
100 " .previous" \
101 : "=&r" (err), "=r" (val) \
102 : "r" (addr), "i" (-EFAULT)); \
103 }
104
105 #define __get_user_unknown(val, size, ptr, err) do { \
106 err = 0; \
107 if (__copy_from_user(&(val), ptr, size)) { \
108 err = -EFAULT; \
109 } \
110 } while (0)
111
112 #define __get_user_common(val, size, ptr, err) \
113 do { \
114 switch (size) { \
115 case 1: \
116 __get_user_asm(val, "ldbu", ptr, err); \
117 break; \
118 case 2: \
119 __get_user_asm(val, "ldhu", ptr, err); \
120 break; \
121 case 4: \
122 __get_user_asm(val, "ldw", ptr, err); \
123 break; \
124 default: \
125 __get_user_unknown(val, size, ptr, err); \
126 break; \
127 } \
128 } while (0)
129
130 #define __get_user(x, ptr) \
131 ({ \
132 long __gu_err = -EFAULT; \
133 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
134 unsigned long __gu_val = 0; \
135 __get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\
136 (x) = (__force __typeof__(x))__gu_val; \
137 __gu_err; \
138 })
139
140 #define get_user(x, ptr) \
141 ({ \
142 long __gu_err = -EFAULT; \
143 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
144 unsigned long __gu_val = 0; \
145 if (access_ok(VERIFY_READ, __gu_ptr, sizeof(*__gu_ptr))) \
146 __get_user_common(__gu_val, sizeof(*__gu_ptr), \
147 __gu_ptr, __gu_err); \
148 (x) = (__force __typeof__(x))__gu_val; \
149 __gu_err; \
150 })
151
152 #define __put_user_asm(val, insn, ptr, err) \
153 { \
154 __asm__ __volatile__( \
155 " movi %0, %3\n" \
156 "1: " insn " %1, 0(%2)\n" \
157 " movi %0, 0\n" \
158 "2:\n" \
159 " .section __ex_table,\"a\"\n" \
160 " .word 1b, 2b\n" \
161 " .previous\n" \
162 : "=&r" (err) \
163 : "r" (val), "r" (ptr), "i" (-EFAULT)); \
164 }
165
166 #define put_user(x, ptr) \
167 ({ \
168 long __pu_err = -EFAULT; \
169 __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
170 __typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \
171 if (access_ok(VERIFY_WRITE, __pu_ptr, sizeof(*__pu_ptr))) { \
172 switch (sizeof(*__pu_ptr)) { \
173 case 1: \
174 __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
175 break; \
176 case 2: \
177 __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
178 break; \
179 case 4: \
180 __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
181 break; \
182 default: \
183 /* XXX: This looks wrong... */ \
184 __pu_err = 0; \
185 if (copy_to_user(__pu_ptr, &(__pu_val), \
186 sizeof(*__pu_ptr))) \
187 __pu_err = -EFAULT; \
188 break; \
189 } \
190 } \
191 __pu_err; \
192 })
193
194 #define __put_user(x, ptr) put_user(x, ptr)
195
196 #endif /* _ASM_NIOS2_UACCESS_H */
197