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
__clear_user(void __user * to,unsigned long n)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
clear_user(void __user * to,unsigned long n)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 unsigned long __gu_val; \
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" (__gu_val) \
102 : "r" (addr), "i" (-EFAULT)); \
103 val = (__force __typeof__(*(addr)))__gu_val; \
104 }
105
106 extern void __get_user_unknown(void);
107
108 #define __get_user_8(val, ptr, err) do { \
109 u64 __val = 0; \
110 err = 0; \
111 if (raw_copy_from_user(&(__val), ptr, sizeof(val))) { \
112 err = -EFAULT; \
113 } else { \
114 val = (typeof(val))(typeof((val) - (val)))__val; \
115 } \
116 } while (0)
117
118 #define __get_user_common(val, size, ptr, err) \
119 do { \
120 switch (size) { \
121 case 1: \
122 __get_user_asm(val, "ldbu", ptr, err); \
123 break; \
124 case 2: \
125 __get_user_asm(val, "ldhu", ptr, err); \
126 break; \
127 case 4: \
128 __get_user_asm(val, "ldw", ptr, err); \
129 break; \
130 case 8: \
131 __get_user_8(val, ptr, err); \
132 break; \
133 default: \
134 __get_user_unknown(); \
135 break; \
136 } \
137 } while (0)
138
139 #define __get_user(x, ptr) \
140 ({ \
141 long __gu_err = -EFAULT; \
142 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
143 __get_user_common(x, sizeof(*(ptr)), __gu_ptr, __gu_err); \
144 __gu_err; \
145 })
146
147 #define get_user(x, ptr) \
148 ({ \
149 long __gu_err = -EFAULT; \
150 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
151 if (access_ok( __gu_ptr, sizeof(*__gu_ptr))) \
152 __get_user_common(x, sizeof(*__gu_ptr), \
153 __gu_ptr, __gu_err); \
154 __gu_err; \
155 })
156
157 #define __put_user_asm(val, insn, ptr, err) \
158 { \
159 __asm__ __volatile__( \
160 " movi %0, %3\n" \
161 "1: " insn " %1, 0(%2)\n" \
162 " movi %0, 0\n" \
163 "2:\n" \
164 " .section __ex_table,\"a\"\n" \
165 " .word 1b, 2b\n" \
166 " .previous\n" \
167 : "=&r" (err) \
168 : "r" (val), "r" (ptr), "i" (-EFAULT)); \
169 }
170
171 #define put_user(x, ptr) \
172 ({ \
173 long __pu_err = -EFAULT; \
174 __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
175 __typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \
176 if (access_ok(__pu_ptr, sizeof(*__pu_ptr))) { \
177 switch (sizeof(*__pu_ptr)) { \
178 case 1: \
179 __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
180 break; \
181 case 2: \
182 __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
183 break; \
184 case 4: \
185 __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
186 break; \
187 default: \
188 /* XXX: This looks wrong... */ \
189 __pu_err = 0; \
190 if (copy_to_user(__pu_ptr, &(__pu_val), \
191 sizeof(*__pu_ptr))) \
192 __pu_err = -EFAULT; \
193 break; \
194 } \
195 } \
196 __pu_err; \
197 })
198
199 #define __put_user(x, ptr) put_user(x, ptr)
200
201 #endif /* _ASM_NIOS2_UACCESS_H */
202