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/* MN10300 Optimised checksumming wrappers
*
* Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <asm/byteorder.h>
#include <linux/uaccess.h>
#include <asm/checksum.h>
#include "internal.h"
static inline unsigned short from32to16(__wsum sum)
{
asm(" add %1,%0 \n"
" addc 0xffff,%0 \n"
: "=r" (sum)
: "r" (sum << 16), "0" (sum & 0xffff0000)
: "cc"
);
return sum >> 16;
}
__sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
return ~do_csum(iph, ihl * 4);
}
EXPORT_SYMBOL(ip_fast_csum);
__wsum csum_partial(const void *buff, int len, __wsum sum)
{
__wsum result;
result = do_csum(buff, len);
result += sum;
if (sum > result)
result++;
return result;
}
EXPORT_SYMBOL(csum_partial);
__sum16 ip_compute_csum(const void *buff, int len)
{
return ~from32to16(do_csum(buff, len));
}
EXPORT_SYMBOL(ip_compute_csum);
__wsum csum_partial_copy(const void *src, void *dst, int len, __wsum sum)
{
copy_from_user(dst, src, len);
return csum_partial(dst, len, sum);
}
EXPORT_SYMBOL(csum_partial_copy);
__wsum csum_partial_copy_nocheck(const void *src, void *dst,
int len, __wsum sum)
{
sum = csum_partial(src, len, sum);
memcpy(dst, src, len);
return sum;
}
EXPORT_SYMBOL(csum_partial_copy_nocheck);
__wsum csum_partial_copy_from_user(const void *src, void *dst,
int len, __wsum sum,
int *err_ptr)
{
int missing;
missing = copy_from_user(dst, src, len);
if (missing) {
memset(dst + len - missing, 0, missing);
*err_ptr = -EFAULT;
}
return csum_partial(dst, len, sum);
}
EXPORT_SYMBOL(csum_partial_copy_from_user);
__wsum csum_and_copy_to_user(const void *src, void *dst,
int len, __wsum sum,
int *err_ptr)
{
int missing;
missing = copy_to_user(dst, src, len);
if (missing) {
memset(dst + len - missing, 0, missing);
*err_ptr = -EFAULT;
}
return csum_partial(src, len, sum);
}
EXPORT_SYMBOL(csum_and_copy_to_user);
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