checksum.h

 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/in6.h>
 9
10#define _HAVE_ARCH_IPV6_CSUM
11__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
12			const struct in6_addr *daddr,
13			__u32 len, __u8 proto, __wsum sum);
14
15static inline __sum16 csum_fold(__wsum csum)
16{
17	u32 sum = (__force u32)csum;
18	sum += (sum >> 16) | (sum << 16);
19	return ~(__force __sum16)(sum >> 16);
20}
21#define csum_fold csum_fold
22
23static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
24{
25	__uint128_t tmp;
26	u64 sum;
27	int n = ihl; /* we want it signed */
28
29	tmp = *(const __uint128_t *)iph;
30	iph += 16;
31	n -= 4;
32	tmp += ((tmp >> 64) | (tmp << 64));
33	sum = tmp >> 64;
34	do {
35		sum += *(const u32 *)iph;
36		iph += 4;
37	} while (--n > 0);
38
39	sum += ((sum >> 32) | (sum << 32));
40	return csum_fold((__force __wsum)(sum >> 32));
41}
42#define ip_fast_csum ip_fast_csum
43
44extern unsigned int do_csum(const unsigned char *buff, int len);
45#define do_csum do_csum
46
47#include <asm-generic/checksum.h>
48
49#endif	/* __ASM_CHECKSUM_H */