memory.c

  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, dst, count, &iter))
 29		return -EFAULT;
 30	if (copy_to_iter_fromio((const void __iomem *)src, count, &iter) != count)
 31		return -EFAULT;
 32	return 0;
 33}
 34EXPORT_SYMBOL(copy_to_user_fromio);
 35
 36/**
 37 * copy_to_iter_fromio - copy data from mmio-space to iov_iter
 38 * @src: the source pointer on mmio
 39 * @count: the data size to copy in bytes
 40 * @dst: the destination iov_iter
 41 *
 42 * Copies the data from mmio-space to iov_iter.
 43 *
 44 * Return: number of bytes to be copied
 45 */
 46size_t copy_to_iter_fromio(const void __iomem *src, size_t count,
 47			   struct iov_iter *dst)
 48{
 49#if defined(__i386__) || defined(CONFIG_SPARC32)
 50	return copy_to_iter((const void __force *)src, count, dst);
 51#else
 52	char buf[256];
 53	size_t res = 0;
 54
 55	while (count) {
 56		size_t c = count;
 57		if (c > sizeof(buf))
 58			c = sizeof(buf);
 59		memcpy_fromio(buf, (void __iomem *)src, c);
 60		if (copy_to_iter(buf, c, dst) != c)
 61			return res;
 62		count -= c;
 63		src += c;
 64		res += c;
 65	}
 66	return res;
 67#endif
 68}
 69EXPORT_SYMBOL(copy_to_iter_fromio);
 70
 71/**
 72 * copy_from_user_toio - copy data from user-space to mmio-space
 73 * @dst: the destination pointer on mmio-space
 74 * @src: the source pointer on user-space
 75 * @count: the data size to copy in bytes
 76 *
 77 * Copies the data from user-space to mmio-space.
 78 *
 79 * Return: Zero if successful, or non-zero on failure.
 80 */
 81int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count)
 82{
 83	struct iov_iter iter;
 84
 85	if (import_ubuf(ITER_SOURCE, (void __user *)src, count, &iter))
 86		return -EFAULT;
 87	if (copy_from_iter_toio((void __iomem *)dst, count, &iter) != count)
 88		return -EFAULT;
 89	return 0;
 90}
 91EXPORT_SYMBOL(copy_from_user_toio);
 92
 93/**
 94 * copy_from_iter_toio - copy data from iov_iter to mmio-space
 95 * @dst: the destination pointer on mmio-space
 96 * @count: the data size to copy in bytes
 97 * @src: the source iov_iter
 98 *
 99 * Copies the data from iov_iter to mmio-space.
100 *
101 * Return: number of bytes to be copied
102 */
103size_t copy_from_iter_toio(void __iomem *dst, size_t count,
104			   struct iov_iter *src)
105{
106#if defined(__i386__) || defined(CONFIG_SPARC32)
107	return copy_from_iter((void __force *)dst, count, src);
108#else
109	char buf[256];
110	size_t res = 0;
111
112	while (count) {
113		size_t c = count;
114		if (c > sizeof(buf))
115			c = sizeof(buf);
116		if (copy_from_iter(buf, c, src) != c)
117			return res;
118		memcpy_toio(dst, buf, c);
119		count -= c;
120		dst += c;
121		res += c;
122	}
123	return res;
124#endif
125}
126EXPORT_SYMBOL(copy_from_iter_toio);