/* checksum.h: FRV checksumming * * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #ifndef _ASM_CHECKSUM_H #define _ASM_CHECKSUM_H #include <linux/in6.h> /* * computes the checksum of a memory block at buff, length len, * and adds in "sum" (32-bit) * * returns a 32-bit number suitable for feeding into itself * or csum_tcpudp_magic * * this function must be called with even lengths, except * for the last fragment, which may be odd * * it's best to have buff aligned on a 32-bit boundary */ unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum); /* * the same as csum_partial, but copies from src while it * checksums * * here even more important to align src and dst on a 32-bit (or even * better 64-bit) boundary */ unsigned int csum_partial_copy(const char *src, char *dst, int len, int sum); /* * the same as csum_partial_copy, but copies from user space. * * here even more important to align src and dst on a 32-bit (or even * better 64-bit) boundary */ extern unsigned int csum_partial_copy_from_user(const char __user *src, char *dst, int len, int sum, int *csum_err); #define csum_partial_copy_nocheck(src, dst, len, sum) \ csum_partial_copy((src), (dst), (len), (sum)) /* * This is a version of ip_compute_csum() optimized for IP headers, * which always checksum on 4 octet boundaries. * */ static inline unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl) { unsigned int tmp, inc, sum = 0; asm(" addcc gr0,gr0,gr0,icc0\n" /* clear icc0.C */ " subi %1,#4,%1 \n" "0: \n" " ldu.p @(%1,%3),%4 \n" " subicc %2,#1,%2,icc1 \n" " addxcc.p %4,%0,%0,icc0 \n" " bhi icc1,#2,0b \n" /* fold the 33-bit result into 16-bits */ " addxcc gr0,%0,%0,icc0 \n" " srli %0,#16,%1 \n" " sethi #0,%0 \n" " add %1,%0,%0 \n" " srli %0,#16,%1 \n" " add %1,%0,%0 \n" : "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (inc), "=&r"(tmp) : "0" (sum), "1" (iph), "2" (ihl), "3" (4), "m"(*(volatile struct { int _[100]; } *)iph) : "icc0", "icc1" ); return ~sum; } /* * Fold a partial checksum */ static inline unsigned int csum_fold(unsigned int sum) { unsigned int tmp; asm(" srli %0,#16,%1 \n" " sethi #0,%0 \n" " add %1,%0,%0 \n" " srli %0,#16,%1 \n" " add %1,%0,%0 \n" : "=r"(sum), "=&r"(tmp) : "0"(sum) ); return ~sum; } /* * computes the checksum of the TCP/UDP pseudo-header * returns a 16-bit checksum, already complemented */ static inline unsigned int csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, unsigned short proto, unsigned int sum) { asm(" addcc %1,%0,%0,icc0 \n" " addxcc %2,%0,%0,icc0 \n" " addxcc %3,%0,%0,icc0 \n" " addxcc gr0,%0,%0,icc0 \n" : "=r" (sum) : "r" (daddr), "r" (saddr), "r" (len + proto), "0"(sum) : "icc0" ); return sum; } static inline unsigned short int csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len, unsigned short proto, unsigned int sum) { return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); } /* * this routine is used for miscellaneous IP-like checksums, mainly * in icmp.c */ extern unsigned short ip_compute_csum(const unsigned char * buff, int len); #define _HAVE_ARCH_IPV6_CSUM static inline unsigned short int csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, __u32 len, unsigned short proto, unsigned int sum) { unsigned long tmp, tmp2; asm(" addcc %2,%0,%0,icc0 \n" /* add up the source addr */ " ldi @(%3,0),%1 \n" " addxcc %1,%0,%0,icc0 \n" " ldi @(%3,4),%2 \n" " addxcc %2,%0,%0,icc0 \n" " ldi @(%3,8),%1 \n" " addxcc %1,%0,%0,icc0 \n" " ldi @(%3,12),%2 \n" " addxcc %2,%0,%0,icc0 \n" /* add up the dest addr */ " ldi @(%4,0),%1 \n" " addxcc %1,%0,%0,icc0 \n" " ldi @(%4,4),%2 \n" " addxcc %2,%0,%0,icc0 \n" " ldi @(%4,8),%1 \n" " addxcc %1,%0,%0,icc0 \n" " ldi @(%4,12),%2 \n" " addxcc %2,%0,%0,icc0 \n" /* fold the 33-bit result into 16-bits */ " addxcc gr0,%0,%0,icc0 \n" " srli %0,#16,%1 \n" " sethi #0,%0 \n" " add %1,%0,%0 \n" " srli %0,#16,%1 \n" " add %1,%0,%0 \n" : "=r" (sum), "=&r" (tmp), "=r" (tmp2) : "r" (saddr), "r" (daddr), "0" (sum), "2" (len + proto) : "icc0" ); return ~sum; } #endif /* _ASM_CHECKSUM_H */