/* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright (C) 2016 ARM Ltd. * Copyright (C) 2023 Loongson Technology Corporation Limited */ #ifndef __ASM_CHECKSUM_H #define __ASM_CHECKSUM_H #include <linux/bitops.h> #include <linux/in6.h> #define _HAVE_ARCH_IPV6_CSUM __sum16 csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __u32 len, __u8 proto, __wsum sum); /* * turns a 32-bit partial checksum (e.g. from csum_partial) into a * 1's complement 16-bit checksum. */ static inline __sum16 csum_fold(__wsum sum) { u32 tmp = (__force u32)sum; /* * swap the two 16-bit halves of sum * if there is a carry from adding the two 16-bit halves, * it will carry from the lower half into the upper half, * giving us the correct sum in the upper half. */ return (__force __sum16)(~(tmp + rol32(tmp, 16)) >> 16); } #define csum_fold csum_fold /* * This is a version of ip_compute_csum() optimized for IP headers, * which always checksum on 4 octet boundaries. ihl is the number * of 32-bit words and is always >= 5. */ static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) { u64 sum; __uint128_t tmp; int n = ihl; /* we want it signed */ tmp = *(const __uint128_t *)iph; iph += 16; n -= 4; tmp += ((tmp >> 64) | (tmp << 64)); sum = tmp >> 64; do { sum += *(const u32 *)iph; iph += 4; } while (--n > 0); sum += ror64(sum, 32); return csum_fold((__force __wsum)(sum >> 32)); } #define ip_fast_csum ip_fast_csum extern unsigned int do_csum(const unsigned char *buff, int len); #define do_csum do_csum #include <asm-generic/checksum.h> #endif /* __ASM_CHECKSUM_H */