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 
csum_fold(__wsum csum)15 static 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 
ip_fast_csum(const void * iph,unsigned int ihl)23 static 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 
44 extern 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 */
50