summaryrefslogtreecommitdiffstats
path: root/include/asm-blackfin/uaccess.h
blob: 61e2bfea7cf41b8a3e06a606001fbdcd58eefd3a (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
197
198
199
200
201
202
203
204
205
/*
 * U-boot - uaccess.h
 *
 * Copyright (c) 2005 blackfin.uclinux.org
 *
 * This file is based on
 * Based on: include/asm-m68knommu/uaccess.h
 * Changes made by Lineo Inc.    May 2001
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#ifndef __BLACKFIN_UACCESS_H
#define __BLACKFIN_UACCESS_H

/*
 * User space memory access functions
 */
#include <asm/segment.h>
#include <asm/errno.h>

#define VERIFY_READ	0
#define VERIFY_WRITE	1

/* We let the MMU do all checking */
static inline int access_ok(int type, const void *addr, unsigned long size)
{
	return ((unsigned long)addr < 0x10f00000);	/* need final decision - Tony */
}

static inline int verify_area(int type, const void *addr, unsigned long size)
{
	return access_ok(type, addr, size) ? 0 : -EFAULT;
}

/*
 * The exception table consists of pairs of addresses: the first is the
 * address of an instruction that is allowed to fault, and the second is
 * the address at which the program should continue.  No registers are
 * modified, so it is entirely up to the continuation code to figure out
 * what to do.
 *
 * All the routines below use bits of fixup code that are out of line
 * with the main instruction path.  This means when everything is well,
 * we don't even have to jump over them.  Further, they do not intrude
 * on our cache or tlb entries.
 */

struct exception_table_entry {
	unsigned long insn, fixup;
};

/* Returns 0 if exception not found and fixup otherwise.  */
extern unsigned long search_exception_table(unsigned long);

/*
 * These are the main single-value transfer routines.  They automatically
 * use the right size if we just have the right pointer type.
 */

#define put_user(x, ptr)				\
({							\
    int __pu_err = 0;					\
    typeof(*(ptr)) __pu_val = (x);			\
    switch (sizeof (*(ptr))) {				\
    case 1:						\
	__put_user_asm(__pu_err, __pu_val, ptr, B);	\
	break;						\
    case 2:						\
	__put_user_asm(__pu_err, __pu_val, ptr, W);	\
	break;						\
    case 4:						\
	__put_user_asm(__pu_err, __pu_val, ptr,  );	\
	break;						\
    default:						\
	__pu_err = __put_user_bad();			\
	break;						\
    }							\
    __pu_err;						\
})
/*
 * [pregs] = dregs  ==> 32bits
 * H[pregs] = dregs  ==> 16bits
 * B[pregs] = dregs  ==> 8 bits
 */

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

static inline int bad_user_access_length(void)
{
	panic("bad_user_access_length");
	return -1;
}

#define __put_user_bad() (bad_user_access_length(), (-EFAULT))

/*
 * Tell gcc we read from memory instead of writing: this is because
 * we do not write to any memory gcc knows about, so there are no
 * aliasing issues.
 */

#define __ptr(x) ((unsigned long *)(x))

#define __put_user_asm(err,x,ptr,bhw)					\
	__asm__ (#bhw"[%1] = %0;\n\t"					\
		:	/* no outputs */				\
		:"d" (x),"a" (__ptr(ptr)) : "memory")

#define get_user(x, ptr)						\
({									\
	int __gu_err = 0;						\
	typeof(*(ptr)) __gu_val = 0;					\
	switch (sizeof(*(ptr))) {					\
	case 1:								\
		__get_user_asm(__gu_err, __gu_val, ptr, B, "=d",(Z));	\
		break;							\
	case 2:								\
		__get_user_asm(__gu_err, __gu_val, ptr, W, "=r",(Z));	\
		break;							\
	case 4:								\
		__get_user_asm(__gu_err, __gu_val, ptr,  , "=r",);	\
		break;							\
	default:							\
		__gu_val = 0;						\
		__gu_err = __get_user_bad();				\
		break;							\
	}								\
	(x) = __gu_val;							\
	__gu_err;							\
})

/* dregs = [pregs] ==> 32bits
 * H[pregs]   ==> 16bits
 * B[pregs]   ==> 8 bits
 */

#define __get_user(x, ptr)	get_user(x, ptr)
#define __get_user_bad()	(bad_user_access_length(), (-EFAULT))

#define __get_user_asm(err,x,ptr,bhw,reg,option)		\
	__asm__ ("%0 =" #bhw "[%1]"#option";\n\t"		\
		: "=d" (x)					\
		: "a" (__ptr(ptr)))

#define copy_from_user(to, from, n)	(memcpy(to, from, n), 0)
#define copy_to_user(to, from, n)	(memcpy(to, from, n), 0)

#define __copy_from_user(to, from, n)	copy_from_user(to, from, n)
#define __copy_to_user(to, from, n)	copy_to_user(to, from, n)

#define copy_to_user_ret(to,from,n,retval)	({ if (copy_to_user(to,from,n)) return retval; })
#define copy_from_user_ret(to,from,n,retval)	({ if (copy_from_user(to,from,n)) return retval; })

/*
 * Copy a null terminated string from userspace.
 */

static inline long strncpy_from_user(char *dst, const char *src, long count)
{
	char *tmp;
	strncpy(dst, src, count);
	for (tmp = dst; *tmp && count > 0; tmp++, count--) ;
	return (tmp - dst);	/* DAVIDM should we count a NUL ?  check getname */
}

/*
 * Return the size of a string (including the ending 0)
 *
 * Return 0 on exception, a value greater than N if too long
 */
static inline long strnlen_user(const char *src, long n)
{
	return (strlen(src) + 1);	/* DAVIDM make safer */
}

#define strlen_user(str) strnlen_user(str, 32767)

/*
 * Zero Userspace
 */

static inline unsigned long clear_user(void *to, unsigned long n)
{
	memset(to, 0, n);
	return (0);
}

#endif
OpenPOWER on IntegriCloud