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