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 #include <sound/pcm.h>
13 
14 /**
15  * copy_to_user_fromio - copy data from mmio-space to user-space
16  * @dst: the destination pointer on user-space
17  * @src: the source pointer on mmio
18  * @count: the data size to copy in bytes
19  *
20  * Copies the data from mmio-space to user-space.
21  *
22  * Return: Zero if successful, or non-zero on failure.
23  */
copy_to_user_fromio(void __user * dst,const volatile void __iomem * src,size_t count)24 int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count)
25 {
26 	struct iov_iter iter;
27 
28 	if (import_ubuf(ITER_DEST, dst, count, &iter))
29 		return -EFAULT;
30 	return copy_to_iter_fromio(&iter, (const void __iomem *)src, count);
31 }
32 EXPORT_SYMBOL(copy_to_user_fromio);
33 
34 /**
35  * copy_to_iter_fromio - copy data from mmio-space to iov_iter
36  * @dst: the destination iov_iter
37  * @src: the source pointer on mmio
38  * @count: the data size to copy in bytes
39  *
40  * Copies the data from mmio-space to iov_iter.
41  *
42  * Return: Zero if successful, or non-zero on failure.
43  */
copy_to_iter_fromio(struct iov_iter * dst,const void __iomem * src,size_t count)44 int copy_to_iter_fromio(struct iov_iter *dst, const void __iomem *src,
45 			size_t count)
46 {
47 #if defined(__i386__) || defined(CONFIG_SPARC32)
48 	return copy_to_iter((const void __force *)src, count, dst) == count ? 0 : -EFAULT;
49 #else
50 	char buf[256];
51 	while (count) {
52 		size_t c = count;
53 		if (c > sizeof(buf))
54 			c = sizeof(buf);
55 		memcpy_fromio(buf, (void __iomem *)src, c);
56 		if (copy_to_iter(buf, c, dst) != c)
57 			return -EFAULT;
58 		count -= c;
59 		src += c;
60 	}
61 	return 0;
62 #endif
63 }
64 EXPORT_SYMBOL(copy_to_iter_fromio);
65 
66 /**
67  * copy_from_user_toio - copy data from user-space to mmio-space
68  * @dst: the destination pointer on mmio-space
69  * @src: the source pointer on user-space
70  * @count: the data size to copy in bytes
71  *
72  * Copies the data from user-space to mmio-space.
73  *
74  * Return: Zero if successful, or non-zero on failure.
75  */
copy_from_user_toio(volatile void __iomem * dst,const void __user * src,size_t count)76 int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count)
77 {
78 	struct iov_iter iter;
79 
80 	if (import_ubuf(ITER_SOURCE, (void __user *)src, count, &iter))
81 		return -EFAULT;
82 	return copy_from_iter_toio((void __iomem *)dst, &iter, count);
83 }
84 EXPORT_SYMBOL(copy_from_user_toio);
85 
86 /**
87  * copy_from_iter_toio - copy data from iov_iter to mmio-space
88  * @dst: the destination pointer on mmio-space
89  * @src: the source iov_iter
90  * @count: the data size to copy in bytes
91  *
92  * Copies the data from iov_iter to mmio-space.
93  *
94  * Return: Zero if successful, or non-zero on failure.
95  */
copy_from_iter_toio(void __iomem * dst,struct iov_iter * src,size_t count)96 int copy_from_iter_toio(void __iomem *dst, struct iov_iter *src, size_t count)
97 {
98 #if defined(__i386__) || defined(CONFIG_SPARC32)
99 	return copy_from_iter((void __force *)dst, count, src) == count ? 0 : -EFAULT;
100 #else
101 	char buf[256];
102 	while (count) {
103 		size_t c = count;
104 		if (c > sizeof(buf))
105 			c = sizeof(buf);
106 		if (copy_from_iter(buf, c, src) != c)
107 			return -EFAULT;
108 		memcpy_toio(dst, buf, c);
109 		count -= c;
110 		dst += c;
111 	}
112 	return 0;
113 #endif
114 }
115 EXPORT_SYMBOL(copy_from_iter_toio);
116