1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * S390 fast network checksum routines 4 * 5 * S390 version 6 * Copyright IBM Corp. 1999 7 * Author(s): Ulrich Hild (first version) 8 * Martin Schwidefsky (heavily optimized CKSM version) 9 * D.J. Barrow (third attempt) 10 */ 11 12#ifndef _S390_CHECKSUM_H 13#define _S390_CHECKSUM_H 14 15#include <linux/instrumented.h> 16#include <linux/in6.h> 17 18static inline __wsum cksm(const void *buff, int len, __wsum sum) 19{ 20 union register_pair rp = { 21 .even = (unsigned long)buff, 22 .odd = (unsigned long)len, 23 }; 24 25 instrument_read(buff, len); 26 asm volatile("\n" 27 "0: cksm %[sum],%[rp]\n" 28 " jo 0b\n" 29 : [sum] "+&d" (sum), [rp] "+&d" (rp.pair) : : "cc", "memory"); 30 return sum; 31} 32 33__wsum csum_partial(const void *buff, int len, __wsum sum); 34 35#define _HAVE_ARCH_CSUM_AND_COPY 36__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len); 37 38/* 39 * Fold a partial checksum without adding pseudo headers. 40 */ 41static inline __sum16 csum_fold(__wsum sum) 42{ 43 u32 csum = (__force u32) sum; 44 45 csum += (csum >> 16) | (csum << 16); 46 csum >>= 16; 47 return (__force __sum16) ~csum; 48} 49 50/* 51 * This is a version of ip_compute_csum() optimized for IP headers, 52 * which always checksums on 4 octet boundaries. 53 */ 54static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 55{ 56 __u64 csum = 0; 57 __u32 *ptr = (u32 *)iph; 58 59 csum += *ptr++; 60 csum += *ptr++; 61 csum += *ptr++; 62 csum += *ptr++; 63 ihl -= 4; 64 while (ihl--) 65 csum += *ptr++; 66 csum += (csum >> 32) | (csum << 32); 67 return csum_fold((__force __wsum)(csum >> 32)); 68} 69 70/* 71 * Computes the checksum of the TCP/UDP pseudo-header. 72 * Returns a 32-bit checksum. 73 */ 74static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, 75 __u8 proto, __wsum sum) 76{ 77 __u64 csum = (__force __u64)sum; 78 79 csum += (__force __u32)saddr; 80 csum += (__force __u32)daddr; 81 csum += len; 82 csum += proto; 83 csum += (csum >> 32) | (csum << 32); 84 return (__force __wsum)(csum >> 32); 85} 86 87/* 88 * Computes the checksum of the TCP/UDP pseudo-header. 89 * Returns a 16-bit checksum, already complemented. 90 */ 91static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, 92 __u8 proto, __wsum sum) 93{ 94 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 95} 96 97/* 98 * Used for miscellaneous IP-like checksums, mainly icmp. 99 */ 100static inline __sum16 ip_compute_csum(const void *buff, int len) 101{ 102 return csum_fold(csum_partial(buff, len, 0)); 103} 104 105#define _HAVE_ARCH_IPV6_CSUM 106static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 107 const struct in6_addr *daddr, 108 __u32 len, __u8 proto, __wsum csum) 109{ 110 __u64 sum = (__force __u64)csum; 111 112 sum += (__force __u32)saddr->s6_addr32[0]; 113 sum += (__force __u32)saddr->s6_addr32[1]; 114 sum += (__force __u32)saddr->s6_addr32[2]; 115 sum += (__force __u32)saddr->s6_addr32[3]; 116 sum += (__force __u32)daddr->s6_addr32[0]; 117 sum += (__force __u32)daddr->s6_addr32[1]; 118 sum += (__force __u32)daddr->s6_addr32[2]; 119 sum += (__force __u32)daddr->s6_addr32[3]; 120 sum += len; 121 sum += proto; 122 sum += (sum >> 32) | (sum << 32); 123 return csum_fold((__force __wsum)(sum >> 32)); 124} 125 126#endif /* _S390_CHECKSUM_H */ 127