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/*
* Copyright (C) 2016 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_CHECKSUM_H
#define __ASM_CHECKSUM_H
#include <linux/types.h>
static inline __sum16 csum_fold(__wsum csum)
{
u32 sum = (__force u32)csum;
sum += (sum >> 16) | (sum << 16);
return ~(__force __sum16)(sum >> 16);
}
#define csum_fold csum_fold
static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
__uint128_t tmp;
u64 sum;
int n = ihl; /* we want it signed */
tmp = *(const __uint128_t *)iph;
iph += 16;
n -= 4;
tmp += ((tmp >> 64) | (tmp << 64));
sum = tmp >> 64;
do {
sum += *(const u32 *)iph;
iph += 4;
} while (--n > 0);
sum += ((sum >> 32) | (sum << 32));
return csum_fold((__force u32)(sum >> 32));
}
#define ip_fast_csum ip_fast_csum
#include <asm-generic/checksum.h>
#endif /* __ASM_CHECKSUM_H */
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