summaryrefslogtreecommitdiff
path: root/arch/nios2/include/asm/uaccess.h
blob: e0ea10806491f47f8e9e7b21b8edd938881b1b5b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/*
 * User space memory access functions for Nios II
 *
 * Copyright (C) 2010-2011, Tobias Klauser <tklauser@distanz.ch>
 * Copyright (C) 2009, Wind River Systems Inc
 *   Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#ifndef _ASM_NIOS2_UACCESS_H
#define _ASM_NIOS2_UACCESS_H

#include <linux/string.h>

#include <asm/page.h>

#include <asm/extable.h>

/*
 * Segment stuff
 */
#define MAKE_MM_SEG(s)		((mm_segment_t) { (s) })
#define USER_DS			MAKE_MM_SEG(0x80000000UL)
#define KERNEL_DS		MAKE_MM_SEG(0)

#define get_ds()		(KERNEL_DS)

#define get_fs()		(current_thread_info()->addr_limit)
#define set_fs(seg)		(current_thread_info()->addr_limit = (seg))

#define segment_eq(a, b)	((a).seg == (b).seg)

#define __access_ok(addr, len)			\
	(((signed long)(((long)get_fs().seg) &	\
		((long)(addr) | (((long)(addr)) + (len)) | (len)))) == 0)

#define access_ok(addr, len)		\
	likely(__access_ok((unsigned long)(addr), (unsigned long)(len)))

# define __EX_TABLE_SECTION	".section __ex_table,\"a\"\n"

#define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE)

/*
 * Zero Userspace
 */

static inline unsigned long __must_check __clear_user(void __user *to,
						      unsigned long n)
{
	__asm__ __volatile__ (
		"1:     stb     zero, 0(%1)\n"
		"       addi    %0, %0, -1\n"
		"       addi    %1, %1, 1\n"
		"       bne     %0, zero, 1b\n"
		"2:\n"
		__EX_TABLE_SECTION
		".word  1b, 2b\n"
		".previous\n"
		: "=r" (n), "=r" (to)
		: "0" (n), "1" (to)
	);

	return n;
}

static inline unsigned long __must_check clear_user(void __user *to,
						    unsigned long n)
{
	if (!access_ok(to, n))
		return n;
	return __clear_user(to, n);
}

extern unsigned long
raw_copy_from_user(void *to, const void __user *from, unsigned long n);
extern unsigned long
raw_copy_to_user(void __user *to, const void *from, unsigned long n);
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER

extern long strncpy_from_user(char *__to, const char __user *__from,
			      long __len);
extern __must_check long strlen_user(const char __user *str);
extern __must_check long strnlen_user(const char __user *s, long n);

/* Optimized macros */
#define __get_user_asm(val, insn, addr, err)				\
{									\
	__asm__ __volatile__(						\
	"       movi    %0, %3\n"					\
	"1:   " insn " %1, 0(%2)\n"					\
	"       movi     %0, 0\n"					\
	"2:\n"								\
	"       .section __ex_table,\"a\"\n"				\
	"       .word 1b, 2b\n"						\
	"       .previous"						\
	: "=&r" (err), "=r" (val)					\
	: "r" (addr), "i" (-EFAULT));					\
}

#define __get_user_unknown(val, size, ptr, err) do {			\
	err = 0;							\
	if (__copy_from_user(&(val), ptr, size)) {			\
		err = -EFAULT;						\
	}								\
	} while (0)

#define __get_user_common(val, size, ptr, err)				\
do {									\
	switch (size) {							\
	case 1:								\
		__get_user_asm(val, "ldbu", ptr, err);			\
		break;							\
	case 2:								\
		__get_user_asm(val, "ldhu", ptr, err);			\
		break;							\
	case 4:								\
		__get_user_asm(val, "ldw", ptr, err);			\
		break;							\
	default:							\
		__get_user_unknown(val, size, ptr, err);		\
		break;							\
	}								\
} while (0)

#define __get_user(x, ptr)						\
	({								\
	long __gu_err = -EFAULT;					\
	const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);		\
	unsigned long __gu_val = 0;					\
	__get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\
	(x) = (__force __typeof__(x))__gu_val;				\
	__gu_err;							\
	})

#define get_user(x, ptr)						\
({									\
	long __gu_err = -EFAULT;					\
	const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);		\
	unsigned long __gu_val = 0;					\
	if (access_ok( __gu_ptr, sizeof(*__gu_ptr)))	\
		__get_user_common(__gu_val, sizeof(*__gu_ptr),		\
			__gu_ptr, __gu_err);				\
	(x) = (__force __typeof__(x))__gu_val;				\
	__gu_err;							\
})

#define __put_user_asm(val, insn, ptr, err)				\
{									\
	__asm__ __volatile__(						\
	"       movi    %0, %3\n"					\
	"1:   " insn " %1, 0(%2)\n"					\
	"       movi     %0, 0\n"					\
	"2:\n"								\
	"       .section __ex_table,\"a\"\n"				\
	"       .word 1b, 2b\n"						\
	"       .previous\n"						\
	: "=&r" (err)							\
	: "r" (val), "r" (ptr), "i" (-EFAULT));				\
}

#define put_user(x, ptr)						\
({									\
	long __pu_err = -EFAULT;					\
	__typeof__(*(ptr)) __user *__pu_ptr = (ptr);			\
	__typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x);		\
	if (access_ok(__pu_ptr, sizeof(*__pu_ptr))) {	\
		switch (sizeof(*__pu_ptr)) {				\
		case 1:							\
			__put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
			break;						\
		case 2:							\
			__put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
			break;						\
		case 4:							\
			__put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
			break;						\
		default:						\
			/* XXX: This looks wrong... */			\
			__pu_err = 0;					\
			if (copy_to_user(__pu_ptr, &(__pu_val),		\
				sizeof(*__pu_ptr)))			\
				__pu_err = -EFAULT;			\
			break;						\
		}							\
	}								\
	__pu_err;							\
})

#define __put_user(x, ptr) put_user(x, ptr)

#endif /* _ASM_NIOS2_UACCESS_H */