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Linux kernel mirror (for testing)
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kernel
os
linux
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
50static 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
69static 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
77extern unsigned long
78raw_copy_from_user(void *to, const void __user *from, unsigned long n);
79extern unsigned long
80raw_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
84extern long strncpy_from_user(char *__to, const char __user *__from,
85 long __len);
86extern __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 __asm__ __volatile__( \
92 " movi %0, %3\n" \
93 "1: " insn " %1, 0(%2)\n" \
94 " movi %0, 0\n" \
95 "2:\n" \
96 " .section __ex_table,\"a\"\n" \
97 " .word 1b, 2b\n" \
98 " .previous" \
99 : "=&r" (err), "=r" (val) \
100 : "r" (addr), "i" (-EFAULT)); \
101}
102
103#define __get_user_unknown(val, size, ptr, err) do { \
104 err = 0; \
105 if (__copy_from_user(&(val), ptr, size)) { \
106 err = -EFAULT; \
107 } \
108 } while (0)
109
110#define __get_user_common(val, size, ptr, err) \
111do { \
112 switch (size) { \
113 case 1: \
114 __get_user_asm(val, "ldbu", ptr, err); \
115 break; \
116 case 2: \
117 __get_user_asm(val, "ldhu", ptr, err); \
118 break; \
119 case 4: \
120 __get_user_asm(val, "ldw", ptr, err); \
121 break; \
122 default: \
123 __get_user_unknown(val, size, ptr, err); \
124 break; \
125 } \
126} while (0)
127
128#define __get_user(x, ptr) \
129 ({ \
130 long __gu_err = -EFAULT; \
131 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
132 unsigned long __gu_val = 0; \
133 __get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\
134 (x) = (__force __typeof__(x))__gu_val; \
135 __gu_err; \
136 })
137
138#define get_user(x, ptr) \
139({ \
140 long __gu_err = -EFAULT; \
141 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
142 unsigned long __gu_val = 0; \
143 if (access_ok( __gu_ptr, sizeof(*__gu_ptr))) \
144 __get_user_common(__gu_val, sizeof(*__gu_ptr), \
145 __gu_ptr, __gu_err); \
146 (x) = (__force __typeof__(x))__gu_val; \
147 __gu_err; \
148})
149
150#define __put_user_asm(val, insn, ptr, err) \
151{ \
152 __asm__ __volatile__( \
153 " movi %0, %3\n" \
154 "1: " insn " %1, 0(%2)\n" \
155 " movi %0, 0\n" \
156 "2:\n" \
157 " .section __ex_table,\"a\"\n" \
158 " .word 1b, 2b\n" \
159 " .previous\n" \
160 : "=&r" (err) \
161 : "r" (val), "r" (ptr), "i" (-EFAULT)); \
162}
163
164#define put_user(x, ptr) \
165({ \
166 long __pu_err = -EFAULT; \
167 __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
168 __typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \
169 if (access_ok(__pu_ptr, sizeof(*__pu_ptr))) { \
170 switch (sizeof(*__pu_ptr)) { \
171 case 1: \
172 __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
173 break; \
174 case 2: \
175 __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
176 break; \
177 case 4: \
178 __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
179 break; \
180 default: \
181 /* XXX: This looks wrong... */ \
182 __pu_err = 0; \
183 if (copy_to_user(__pu_ptr, &(__pu_val), \
184 sizeof(*__pu_ptr))) \
185 __pu_err = -EFAULT; \
186 break; \
187 } \
188 } \
189 __pu_err; \
190})
191
192#define __put_user(x, ptr) put_user(x, ptr)
193
194#endif /* _ASM_NIOS2_UACCESS_H */