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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2016 ARM Ltd.
4 */
5#ifndef __ASM_CHECKSUM_H
6#define __ASM_CHECKSUM_H
7
8#include <linux/types.h>
9
10static inline __sum16 csum_fold(__wsum csum)
11{
12 u32 sum = (__force u32)csum;
13 sum += (sum >> 16) | (sum << 16);
14 return ~(__force __sum16)(sum >> 16);
15}
16#define csum_fold csum_fold
17
18static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
19{
20 __uint128_t tmp;
21 u64 sum;
22
23 tmp = *(const __uint128_t *)iph;
24 iph += 16;
25 ihl -= 4;
26 tmp += ((tmp >> 64) | (tmp << 64));
27 sum = tmp >> 64;
28 do {
29 sum += *(const u32 *)iph;
30 iph += 4;
31 } while (--ihl);
32
33 sum += ((sum >> 32) | (sum << 32));
34 return csum_fold((__force u32)(sum >> 32));
35}
36#define ip_fast_csum ip_fast_csum
37
38#include <asm-generic/checksum.h>
39
40#endif /* __ASM_CHECKSUM_H */