1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * Copyright (C) 2016 ARM Ltd.
5 #ifndef __ASM_CHECKSUM_H
6 #define __ASM_CHECKSUM_H
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);
15 static inline __sum16 csum_fold(__wsum csum)
17 u32 sum = (__force u32)csum;
18 sum += (sum >> 16) | (sum << 16);
19 return ~(__force __sum16)(sum >> 16);
21 #define csum_fold csum_fold
23 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
27 int n = ihl; /* we want it signed */
29 tmp = *(const __uint128_t *)iph;
32 tmp += ((tmp >> 64) | (tmp << 64));
35 sum += *(const u32 *)iph;
39 sum += ((sum >> 32) | (sum << 32));
40 return csum_fold((__force __wsum)(sum >> 32));
42 #define ip_fast_csum ip_fast_csum
44 extern unsigned int do_csum(const unsigned char *buff, int len);
45 #define do_csum do_csum
47 #include <asm-generic/checksum.h>
49 #endif /* __ASM_CHECKSUM_H */