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561b4fa9c1
Add two more helpers for copying memory between iov_iter and iomem, which will be used by the new PCM copy ops in a few drivers. The existing helpers became wrappers of those now. Note that copy_from/to_iter() returns the copied bytes, hence the error condition is adjusted accordingly. Link: https://lore.kernel.org/r/20230815190136.8987-4-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
115 lines
3 KiB
C
115 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
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*
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* Misc memory accessors
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*/
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#include <linux/export.h>
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#include <linux/io.h>
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#include <linux/uaccess.h>
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#include <sound/core.h>
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#include <sound/pcm.h>
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/**
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* copy_to_user_fromio - copy data from mmio-space to user-space
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* @dst: the destination pointer on user-space
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* @src: the source pointer on mmio
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* @count: the data size to copy in bytes
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*
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* Copies the data from mmio-space to user-space.
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*
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* Return: Zero if successful, or non-zero on failure.
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*/
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int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count)
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{
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struct iov_iter iter;
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if (import_ubuf(ITER_DEST, dst, count, &iter))
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return -EFAULT;
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return copy_to_iter_fromio(&iter, (const void __iomem *)src, count);
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}
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EXPORT_SYMBOL(copy_to_user_fromio);
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/**
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* copy_to_iter_fromio - copy data from mmio-space to iov_iter
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* @dst: the destination iov_iter
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* @src: the source pointer on mmio
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* @count: the data size to copy in bytes
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*
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* Copies the data from mmio-space to iov_iter.
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*
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* Return: Zero if successful, or non-zero on failure.
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*/
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int copy_to_iter_fromio(struct iov_iter *dst, const void __iomem *src,
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size_t count)
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{
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#if defined(__i386__) || defined(CONFIG_SPARC32)
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return copy_to_iter((const void __force *)src, count, dst) == count ? 0 : -EFAULT;
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#else
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char buf[256];
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while (count) {
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size_t c = count;
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if (c > sizeof(buf))
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c = sizeof(buf);
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memcpy_fromio(buf, (void __iomem *)src, c);
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if (copy_to_iter(buf, c, dst) != c)
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return -EFAULT;
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count -= c;
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src += c;
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}
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return 0;
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#endif
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}
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EXPORT_SYMBOL(copy_to_iter_fromio);
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/**
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* copy_from_user_toio - copy data from user-space to mmio-space
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* @dst: the destination pointer on mmio-space
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* @src: the source pointer on user-space
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* @count: the data size to copy in bytes
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*
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* Copies the data from user-space to mmio-space.
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*
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* Return: Zero if successful, or non-zero on failure.
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*/
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int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count)
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{
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struct iov_iter iter;
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if (import_ubuf(ITER_SOURCE, (void __user *)src, count, &iter))
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return -EFAULT;
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return copy_from_iter_toio((void __iomem *)dst, &iter, count);
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}
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EXPORT_SYMBOL(copy_from_user_toio);
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/**
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* copy_from_iter_toio - copy data from iov_iter to mmio-space
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* @dst: the destination pointer on mmio-space
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* @src: the source iov_iter
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* @count: the data size to copy in bytes
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*
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* Copies the data from iov_iter to mmio-space.
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*
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* Return: Zero if successful, or non-zero on failure.
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*/
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int copy_from_iter_toio(void __iomem *dst, struct iov_iter *src, size_t count)
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{
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#if defined(__i386__) || defined(CONFIG_SPARC32)
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return copy_from_iter((void __force *)dst, count, src) == count ? 0 : -EFAULT;
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#else
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char buf[256];
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while (count) {
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size_t c = count;
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if (c > sizeof(buf))
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c = sizeof(buf);
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if (copy_from_iter(buf, c, src) != c)
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return -EFAULT;
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memcpy_toio(dst, buf, c);
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count -= c;
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dst += c;
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}
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return 0;
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#endif
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}
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EXPORT_SYMBOL(copy_from_iter_toio);
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