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DEFINITIONS
This source file includes following definitions.
- ip_fast_csum
- csum_fold
- csum_tcpudp_nofold
- csum_tcpudp_magic
- csum_ipv6_magic
/* 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
*/
__wsum csum_partial(const void *buff, int len, __wsum 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
*/
__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum 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 __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
int len, __wsum sum, int *csum_err);
/*
* This is a version of ip_compute_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries.
*
*/
static inline
__sum16 ip_fast_csum(const void *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", "memory"
);
return (__force __sum16)~sum;
}
/*
* Fold a partial checksum
*/
static inline __sum16 csum_fold(__wsum 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 (__force __sum16)~sum;
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static inline __wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
unsigned short proto, __wsum 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 __sum16
csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
unsigned short proto, __wsum 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 __sum16 ip_compute_csum(const void *buff, int len);
#define _HAVE_ARCH_IPV6_CSUM
static inline __sum16
csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
__u32 len, unsigned short proto, __wsum 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 (__force __sum16)~sum;
}
#endif /* _ASM_CHECKSUM_H */