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 uaccess_kernel() (get_fs().seg == KERNEL_DS.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 strnlen_user(const char __user *s, long n);
87
88 /* Optimized macros */
89 #define __get_user_asm(val, insn, addr, err) \
90 { \
91 unsigned long __gu_val; \
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" (__gu_val) \
101 : "r" (addr), "i" (-EFAULT)); \
102 val = (__force __typeof__(*(addr)))__gu_val; \
103 }
104
105 extern void __get_user_unknown(void);
106
107 #define __get_user_8(val, ptr, err) do { \
108 u64 __val = 0; \
109 err = 0; \
110 if (raw_copy_from_user(&(__val), ptr, sizeof(val))) { \
111 err = -EFAULT; \
112 } else { \
113 val = (typeof(val))(typeof((val) - (val)))__val; \
114 } \
115 } while (0)
116
117 #define __get_user_common(val, size, ptr, err) \
118 do { \
119 switch (size) { \
120 case 1: \
121 __get_user_asm(val, "ldbu", ptr, err); \
122 break; \
123 case 2: \
124 __get_user_asm(val, "ldhu", ptr, err); \
125 break; \
126 case 4: \
127 __get_user_asm(val, "ldw", ptr, err); \
128 break; \
129 case 8: \
130 __get_user_8(val, ptr, err); \
131 break; \
132 default: \
133 __get_user_unknown(); \
134 break; \
135 } \
136 } while (0)
137
138 #define __get_user(x, ptr) \
139 ({ \
140 long __gu_err = -EFAULT; \
141 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
142 __get_user_common(x, sizeof(*(ptr)), __gu_ptr, __gu_err); \
143 __gu_err; \
144 })
145
146 #define get_user(x, ptr) \
147 ({ \
148 long __gu_err = -EFAULT; \
149 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
150 if (access_ok( __gu_ptr, sizeof(*__gu_ptr))) \
151 __get_user_common(x, sizeof(*__gu_ptr), \
152 __gu_ptr, __gu_err); \
153 __gu_err; \
154 })
155
156 #define __put_user_asm(val, insn, ptr, err) \
157 { \
158 __asm__ __volatile__( \
159 " movi %0, %3\n" \
160 "1: " insn " %1, 0(%2)\n" \
161 " movi %0, 0\n" \
162 "2:\n" \
163 " .section __ex_table,\"a\"\n" \
164 " .word 1b, 2b\n" \
165 " .previous\n" \
166 : "=&r" (err) \
167 : "r" (val), "r" (ptr), "i" (-EFAULT)); \
168 }
169
170 #define put_user(x, ptr) \
171 ({ \
172 long __pu_err = -EFAULT; \
173 __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
174 __typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \
175 if (access_ok(__pu_ptr, sizeof(*__pu_ptr))) { \
176 switch (sizeof(*__pu_ptr)) { \
177 case 1: \
178 __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
179 break; \
180 case 2: \
181 __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
182 break; \
183 case 4: \
184 __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
185 break; \
186 default: \
187 /* XXX: This looks wrong... */ \
188 __pu_err = 0; \
189 if (copy_to_user(__pu_ptr, &(__pu_val), \
190 sizeof(*__pu_ptr))) \
191 __pu_err = -EFAULT; \
192 break; \
193 } \
194 } \
195 __pu_err; \
196 })
197
198 #define __put_user(x, ptr) put_user(x, ptr)
199
200 #endif /* _ASM_NIOS2_UACCESS_H */
201