1/* MN10300 Userspace accessor functions
2 *
3 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public Licence
9 * as published by the Free Software Foundation; either version
10 * 2 of the Licence, or (at your option) any later version.
11 */
12#include <asm/uaccess.h>
13
14unsigned long
15__generic_copy_to_user(void *to, const void *from, unsigned long n)
16{
17	if (access_ok(VERIFY_WRITE, to, n))
18		__copy_user(to, from, n);
19	return n;
20}
21
22unsigned long
23__generic_copy_from_user(void *to, const void *from, unsigned long n)
24{
25	if (access_ok(VERIFY_READ, from, n))
26		__copy_user_zeroing(to, from, n);
27	return n;
28}
29
30/*
31 * Copy a null terminated string from userspace.
32 */
33#define __do_strncpy_from_user(dst, src, count, res)		\
34do {								\
35	int w;							\
36	asm volatile(						\
37		"	mov	%1,%0\n"			\
38		"	cmp	0,%1\n"				\
39		"	beq	2f\n"				\
40		"0:\n"						\
41		"	movbu	(%5),%2\n"			\
42		"1:\n"						\
43		"	movbu	%2,(%6)\n"			\
44		"	inc	%5\n"				\
45		"	inc	%6\n"				\
46		"	cmp	0,%2\n"				\
47		"	beq	2f\n"				\
48		"	add	-1,%1\n"			\
49		"	bne	0b\n"				\
50		"2:\n"						\
51		"	sub	%1,%0\n"			\
52		"3:\n"						\
53		"	.section .fixup,\"ax\"\n"		\
54		"4:\n"						\
55		"	mov	%3,%0\n"			\
56		"	jmp	3b\n"				\
57		"	.previous\n"				\
58		"	.section __ex_table,\"a\"\n"		\
59		"	.balign 4\n"				\
60		"	.long 0b,4b\n"				\
61		"	.long 1b,4b\n"				\
62		"	.previous"				\
63		:"=&r"(res), "=r"(count), "=&r"(w)		\
64		:"i"(-EFAULT), "1"(count), "a"(src), "a"(dst)	\
65		: "memory", "cc");					\
66} while (0)
67
68long
69__strncpy_from_user(char *dst, const char *src, long count)
70{
71	long res;
72	__do_strncpy_from_user(dst, src, count, res);
73	return res;
74}
75
76long
77strncpy_from_user(char *dst, const char *src, long count)
78{
79	long res = -EFAULT;
80	if (access_ok(VERIFY_READ, src, 1))
81		__do_strncpy_from_user(dst, src, count, res);
82	return res;
83}
84
85
86/*
87 * Clear a userspace memory
88 */
89#define __do_clear_user(addr, size)		\
90do {						\
91	int w;					\
92	asm volatile(				\
93		"	cmp 0,%0\n"		\
94		"	beq 1f\n"		\
95		"	clr %1\n"		\
96		"0:	movbu %1,(%3,%2)\n"	\
97		"	inc %3\n"		\
98		"	cmp %0,%3\n"		\
99		"	bne 0b\n"		\
100		"1:\n"				\
101		"	sub %3,%0\n"		\
102		"2:\n"				\
103		".section .fixup,\"ax\"\n"	\
104		"3:	jmp 2b\n"		\
105		".previous\n"			\
106		".section __ex_table,\"a\"\n"	\
107		"       .balign 4\n"		\
108		"       .long 0b,3b\n"		\
109		".previous\n"			\
110		: "+r"(size), "=&r"(w)		\
111		: "a"(addr), "d"(0)		\
112		: "memory", "cc");		\
113} while (0)
114
115unsigned long
116__clear_user(void *to, unsigned long n)
117{
118	__do_clear_user(to, n);
119	return n;
120}
121
122unsigned long
123clear_user(void *to, unsigned long n)
124{
125	if (access_ok(VERIFY_WRITE, to, n))
126		__do_clear_user(to, n);
127	return n;
128}
129
130/*
131 * Return the size of a string (including the ending 0)
132 *
133 * Return 0 on exception, a value greater than N if too long
134 */
135long strnlen_user(const char *s, long n)
136{
137	unsigned long res, w;
138
139	if (!__addr_ok(s))
140		return 0;
141
142	if (n < 0 || n + (u_long) s > current_thread_info()->addr_limit.seg)
143		n = current_thread_info()->addr_limit.seg - (u_long)s;
144
145	asm volatile(
146		"0:	cmp %4,%0\n"
147		"	beq 2f\n"
148		"1:	movbu (%0,%3),%1\n"
149		"	inc %0\n"
150		"	cmp 0,%1\n"
151		"	beq 3f\n"
152		"	bra 0b\n"
153		"2:	clr %0\n"
154		"3:\n"
155		".section .fixup,\"ax\"\n"
156		"4:	jmp 2b\n"
157		".previous\n"
158		".section __ex_table,\"a\"\n"
159		"	.balign 4\n"
160		"	.long 1b,4b\n"
161		".previous\n"
162		:"=d"(res), "=&r"(w)
163		:"0"(0), "a"(s), "r"(n)
164		: "memory", "cc");
165	return res;
166}
167