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 */
24int 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, buf: dst, len: count, i: &iter))
29 return -EFAULT;
30 return copy_to_iter_fromio(itert: &iter, src: (const void __iomem *)src, count);
31}
32EXPORT_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 */
44int 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(addr: buf, bytes: c, i: dst) != c)
57 return -EFAULT;
58 count -= c;
59 src += c;
60 }
61 return 0;
62#endif
63}
64EXPORT_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 */
76int 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, buf: (void __user *)src, len: count, i: &iter))
81 return -EFAULT;
82 return copy_from_iter_toio(dst: (void __iomem *)dst, iter: &iter, count);
83}
84EXPORT_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 */
96int 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(addr: buf, bytes: c, i: src) != c)
107 return -EFAULT;
108 memcpy_toio(dst, buf, c);
109 count -= c;
110 dst += c;
111 }
112 return 0;
113#endif
114}
115EXPORT_SYMBOL(copy_from_iter_toio);
116

source code of linux/sound/core/memory.c