mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
183 lines
4.7 KiB
C
183 lines
4.7 KiB
C
/* checksum.h: FRV checksumming
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*
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* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _ASM_CHECKSUM_H
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#define _ASM_CHECKSUM_H
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#include <linux/in6.h>
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/*
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* computes the checksum of a memory block at buff, length len,
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* and adds in "sum" (32-bit)
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*
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* returns a 32-bit number suitable for feeding into itself
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* or csum_tcpudp_magic
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*
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* this function must be called with even lengths, except
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* for the last fragment, which may be odd
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*
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* it's best to have buff aligned on a 32-bit boundary
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*/
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unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
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/*
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* the same as csum_partial, but copies from src while it
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* checksums
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*
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* here even more important to align src and dst on a 32-bit (or even
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* better 64-bit) boundary
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*/
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unsigned int csum_partial_copy(const char *src, char *dst, int len, int sum);
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/*
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* the same as csum_partial_copy, but copies from user space.
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*
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* here even more important to align src and dst on a 32-bit (or even
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* better 64-bit) boundary
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*/
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extern unsigned int csum_partial_copy_from_user(const char *src, char *dst,
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int len, int sum, int *csum_err);
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#define csum_partial_copy_nocheck(src, dst, len, sum) \
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csum_partial_copy((src), (dst), (len), (sum))
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/*
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* This is a version of ip_compute_csum() optimized for IP headers,
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* which always checksum on 4 octet boundaries.
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*
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*/
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static inline
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unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl)
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{
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unsigned int tmp, inc, sum = 0;
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asm(" addcc gr0,gr0,gr0,icc0\n" /* clear icc0.C */
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" subi %1,#4,%1 \n"
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"0: \n"
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" ldu.p @(%1,%3),%4 \n"
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" subicc %2,#1,%2,icc1 \n"
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" addxcc.p %4,%0,%0,icc0 \n"
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" bhi icc1,#2,0b \n"
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/* fold the 33-bit result into 16-bits */
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" addxcc gr0,%0,%0,icc0 \n"
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" srli %0,#16,%1 \n"
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" sethi #0,%0 \n"
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" add %1,%0,%0 \n"
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" srli %0,#16,%1 \n"
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" add %1,%0,%0 \n"
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: "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (inc), "=&r"(tmp)
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: "0" (sum), "1" (iph), "2" (ihl), "3" (4),
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"m"(*(volatile struct { int _[100]; } *)iph)
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: "icc0", "icc1"
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);
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return ~sum;
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}
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/*
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* Fold a partial checksum
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*/
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static inline unsigned int csum_fold(unsigned int sum)
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{
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unsigned int tmp;
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asm(" srli %0,#16,%1 \n"
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" sethi #0,%0 \n"
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" add %1,%0,%0 \n"
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" srli %0,#16,%1 \n"
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" add %1,%0,%0 \n"
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: "=r"(sum), "=&r"(tmp)
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: "0"(sum)
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);
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return ~sum;
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}
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/*
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* computes the checksum of the TCP/UDP pseudo-header
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* returns a 16-bit checksum, already complemented
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*/
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static inline unsigned int
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csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
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unsigned short proto, unsigned int sum)
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{
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asm(" addcc %1,%0,%0,icc0 \n"
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" addxcc %2,%0,%0,icc0 \n"
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" addxcc %3,%0,%0,icc0 \n"
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" addxcc gr0,%0,%0,icc0 \n"
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: "=r" (sum)
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: "r" (daddr), "r" (saddr), "r" (len + proto), "0"(sum)
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: "icc0"
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);
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return sum;
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}
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static inline unsigned short int
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csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
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unsigned short proto, unsigned int sum)
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{
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return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
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}
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/*
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* this routine is used for miscellaneous IP-like checksums, mainly
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* in icmp.c
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*/
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extern unsigned short ip_compute_csum(const unsigned char * buff, int len);
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#define _HAVE_ARCH_IPV6_CSUM
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static inline unsigned short int
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csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr,
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__u32 len, unsigned short proto, unsigned int sum)
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{
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unsigned long tmp, tmp2;
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asm(" addcc %2,%0,%0,icc0 \n"
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/* add up the source addr */
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" ldi @(%3,0),%1 \n"
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" addxcc %1,%0,%0,icc0 \n"
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" ldi @(%3,4),%2 \n"
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" addxcc %2,%0,%0,icc0 \n"
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" ldi @(%3,8),%1 \n"
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" addxcc %1,%0,%0,icc0 \n"
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" ldi @(%3,12),%2 \n"
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" addxcc %2,%0,%0,icc0 \n"
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/* add up the dest addr */
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" ldi @(%4,0),%1 \n"
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" addxcc %1,%0,%0,icc0 \n"
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" ldi @(%4,4),%2 \n"
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" addxcc %2,%0,%0,icc0 \n"
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" ldi @(%4,8),%1 \n"
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" addxcc %1,%0,%0,icc0 \n"
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" ldi @(%4,12),%2 \n"
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" addxcc %2,%0,%0,icc0 \n"
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/* fold the 33-bit result into 16-bits */
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" addxcc gr0,%0,%0,icc0 \n"
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" srli %0,#16,%1 \n"
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" sethi #0,%0 \n"
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" add %1,%0,%0 \n"
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" srli %0,#16,%1 \n"
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" add %1,%0,%0 \n"
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: "=r" (sum), "=&r" (tmp), "=r" (tmp2)
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: "r" (saddr), "r" (daddr), "0" (sum), "2" (len + proto)
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: "icc0"
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);
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return ~sum;
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}
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#endif /* _ASM_CHECKSUM_H */
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