xref: /openbmc/linux/sound/core/memory.c (revision cfbb9be8)
1 /*
2  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
3  *
4  *  Misc memory accessors
5  *
6  *
7  *   This program is free software; you can redistribute it and/or modify
8  *   it under the terms of the GNU General Public License as published by
9  *   the Free Software Foundation; either version 2 of the License, or
10  *   (at your option) any later version.
11  *
12  *   This program is distributed in the hope that it will be useful,
13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *   GNU General Public License for more details.
16  *
17  *   You should have received a copy of the GNU General Public License
18  *   along with this program; if not, write to the Free Software
19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
20  *
21  */
22 
23 #include <linux/export.h>
24 #include <linux/io.h>
25 #include <linux/uaccess.h>
26 #include <sound/core.h>
27 
28 /**
29  * copy_to_user_fromio - copy data from mmio-space to user-space
30  * @dst: the destination pointer on user-space
31  * @src: the source pointer on mmio
32  * @count: the data size to copy in bytes
33  *
34  * Copies the data from mmio-space to user-space.
35  *
36  * Return: Zero if successful, or non-zero on failure.
37  */
38 int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count)
39 {
40 #if defined(__i386__) || defined(CONFIG_SPARC32)
41 	return copy_to_user(dst, (const void __force*)src, count) ? -EFAULT : 0;
42 #else
43 	char buf[256];
44 	while (count) {
45 		size_t c = count;
46 		if (c > sizeof(buf))
47 			c = sizeof(buf);
48 		memcpy_fromio(buf, (void __iomem *)src, c);
49 		if (copy_to_user(dst, buf, c))
50 			return -EFAULT;
51 		count -= c;
52 		dst += c;
53 		src += c;
54 	}
55 	return 0;
56 #endif
57 }
58 EXPORT_SYMBOL(copy_to_user_fromio);
59 
60 /**
61  * copy_from_user_toio - copy data from user-space to mmio-space
62  * @dst: the destination pointer on mmio-space
63  * @src: the source pointer on user-space
64  * @count: the data size to copy in bytes
65  *
66  * Copies the data from user-space to mmio-space.
67  *
68  * Return: Zero if successful, or non-zero on failure.
69  */
70 int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count)
71 {
72 #if defined(__i386__) || defined(CONFIG_SPARC32)
73 	return copy_from_user((void __force *)dst, src, count) ? -EFAULT : 0;
74 #else
75 	char buf[256];
76 	while (count) {
77 		size_t c = count;
78 		if (c > sizeof(buf))
79 			c = sizeof(buf);
80 		if (copy_from_user(buf, src, c))
81 			return -EFAULT;
82 		memcpy_toio(dst, buf, c);
83 		count -= c;
84 		dst += c;
85 		src += c;
86 	}
87 	return 0;
88 #endif
89 }
90 EXPORT_SYMBOL(copy_from_user_toio);
91