include/asm/checksum.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  * Copyright (C) 2016 ARM Ltd.
0004  */
0005 #ifndef __ASM_CHECKSUM_H
0006 #define __ASM_CHECKSUM_H
0007
0008 #include <linux/in6.h>
0009
0010 #define _HAVE_ARCH_IPV6_CSUM
0011 __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
0012             const struct in6_addr *daddr,
0013             __u32 len, __u8 proto, __wsum sum);
0014
0015 static inline __sum16 csum_fold(__wsum csum)
0016 {
0017     u32 sum = (__force u32)csum;
0018     sum += (sum >> 16) | (sum << 16);
0019     return ~(__force __sum16)(sum >> 16);
0020 }
0021 #define csum_fold csum_fold
0022
0023 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
0024 {
0025     __uint128_t tmp;
0026     u64 sum;
0027     int n = ihl; /* we want it signed */
0028
0029     tmp = *(const __uint128_t *)iph;
0030     iph += 16;
0031     n -= 4;
0032     tmp += ((tmp >> 64) | (tmp << 64));
0033     sum = tmp >> 64;
0034     do {
0035         sum += *(const u32 *)iph;
0036         iph += 4;
0037     } while (--n > 0);
0038
0039     sum += ((sum >> 32) | (sum << 32));
0040     return csum_fold((__force __wsum)(sum >> 32));
0041 }
0042 #define ip_fast_csum ip_fast_csum
0043
0044 extern unsigned int do_csum(const unsigned char *buff, int len);
0045 #define do_csum do_csum
0046
0047 #include <asm-generic/checksum.h>
0048
0049 #endif  /* __ASM_CHECKSUM_H */