xref: /openbmc/linux/sound/core/memory.c (revision f5c27da4)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4  *
5  *  Misc memory accessors
6  */
7 
8 #include <linux/export.h>
9 #include <linux/io.h>
10 #include <linux/uaccess.h>
11 #include <sound/core.h>
12 
13 /**
14  * copy_to_user_fromio - copy data from mmio-space to user-space
15  * @dst: the destination pointer on user-space
16  * @src: the source pointer on mmio
17  * @count: the data size to copy in bytes
18  *
19  * Copies the data from mmio-space to user-space.
20  *
21  * Return: Zero if successful, or non-zero on failure.
22  */
23 int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count)
24 {
25 #if defined(__i386__) || defined(CONFIG_SPARC32)
26 	return copy_to_user(dst, (const void __force*)src, count) ? -EFAULT : 0;
27 #else
28 	char buf[256];
29 	while (count) {
30 		size_t c = count;
31 		if (c > sizeof(buf))
32 			c = sizeof(buf);
33 		memcpy_fromio(buf, (void __iomem *)src, c);
34 		if (copy_to_user(dst, buf, c))
35 			return -EFAULT;
36 		count -= c;
37 		dst += c;
38 		src += c;
39 	}
40 	return 0;
41 #endif
42 }
43 EXPORT_SYMBOL(copy_to_user_fromio);
44 
45 /**
46  * copy_from_user_toio - copy data from user-space to mmio-space
47  * @dst: the destination pointer on mmio-space
48  * @src: the source pointer on user-space
49  * @count: the data size to copy in bytes
50  *
51  * Copies the data from user-space to mmio-space.
52  *
53  * Return: Zero if successful, or non-zero on failure.
54  */
55 int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count)
56 {
57 #if defined(__i386__) || defined(CONFIG_SPARC32)
58 	return copy_from_user((void __force *)dst, src, count) ? -EFAULT : 0;
59 #else
60 	char buf[256];
61 	while (count) {
62 		size_t c = count;
63 		if (c > sizeof(buf))
64 			c = sizeof(buf);
65 		if (copy_from_user(buf, src, c))
66 			return -EFAULT;
67 		memcpy_toio(dst, buf, c);
68 		count -= c;
69 		dst += c;
70 		src += c;
71 	}
72 	return 0;
73 #endif
74 }
75 EXPORT_SYMBOL(copy_from_user_toio);
76