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/types.h> 9 10 static inline __sum16 csum_fold(__wsum csum) 11 { 12 u32 sum = (__force u32)csum; 13 sum += (sum >> 16) | (sum << 16); 14 return ~(__force __sum16)(sum >> 16); 15 } 16 #define csum_fold csum_fold 17 18 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 19 { 20 __uint128_t tmp; 21 u64 sum; 22 23 tmp = *(const __uint128_t *)iph; 24 iph += 16; 25 ihl -= 4; 26 tmp += ((tmp >> 64) | (tmp << 64)); 27 sum = tmp >> 64; 28 do { 29 sum += *(const u32 *)iph; 30 iph += 4; 31 } while (--ihl); 32 33 sum += ((sum >> 32) | (sum << 32)); 34 return csum_fold((__force u32)(sum >> 32)); 35 } 36 #define ip_fast_csum ip_fast_csum 37 38 #include <asm-generic/checksum.h> 39 40 #endif /* __ASM_CHECKSUM_H */ 41