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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*-
* Copyright (c) 2001 by Thomas Moestl <tmm@FreeBSD.org>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* from tahoe: in_cksum.c 1.2 86/01/05
* from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91
* from: FreeBSD: src/sys/i386/i386/in_cksum.c,v 1.22 2000/11/25
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <machine/in_cksum.h>
/*
* Checksum routine for Internet Protocol family headers.
*
* This routine is very heavily used in the network
* code and should be modified for each CPU to be as fast as possible.
*
* This implementation is a sparc64 version. Most code was taken over
* and adapted from the i386. Some optimizations were changed to achieve
* (hopefully) better performance.
* This uses 64-bit loads, but 32-bit additions due to the lack of a 64-bit
* add-with-carry operation.
*/
/*
* REDUCE() is actually not used that frequently... maybe a C implementation
* would suffice.
*/
#define REDUCE(sum, tmp) __asm( \
"sll %2, 16, %1\n" \
"addcc %2, %1, %0\n" \
"srl %0, 16, %0\n" \
"addc %0, 0, %0" : "=r" (sum), "=&r" (tmp) : "0" (sum) : "cc")
/*
* Note that some of these macros depend on the flags being preserved
* between calls, thus they have to be used within a single __asm().
*/
#define LD64_ADD32(n, mod) \
"ldx [%3 + " #n "], %1\n" \
"add" #mod " %2, %1, %0\n" \
"srlx %1, 32, %1\n" \
"addccc %0, %1, %0\n"
#define LD32_ADD32(n, mod) \
"lduw [%3 + " #n "], %1\n" \
"add" #mod " %2, %1, %0\n"
#define MOP(sum, tmp, addr) \
"addc %2, 0, %0" \
: "=r" (sum), "=&r" (tmp) : "0" (sum), "r" (addr) : "cc"
u_short
in_cksum_skip(struct mbuf *m, int len, int skip)
{
u_short *w;
unsigned long tmp, sum = 0;
int mlen = 0;
int byte_swapped = 0;
u_short su = 0;
len -= skip;
for (; skip > 0 && m != NULL; m = m->m_next) {
if (m->m_len > skip) {
mlen = m->m_len - skip;
w = (u_short *)(mtod(m, u_char *) + skip);
goto skip_start;
} else
skip -= m->m_len;
}
for (; m != NULL && len > 0; m = m->m_next) {
if (m->m_len == 0)
continue;
w = mtod(m, u_short *);
if (mlen == -1) {
/*
* The first byte of this mbuf is the continuation
* of a word spanning between this mbuf and the
* last mbuf.
*
* The high order byte of su is already saved when
* scanning previous mbuf. sum was REDUCEd when we
* found mlen == -1
*/
sum += su | *(u_char *)w;
w = (u_short *)((u_char *)w + 1);
mlen = m->m_len - 1;
len--;
} else
mlen = m->m_len;
skip_start:
if (len < mlen)
mlen = len;
len -= mlen;
/*
* Force to a 8-byte boundary first so that we can use
* LD64_ADD32.
*/
if (((u_long)w & 7) != 0) {
REDUCE(sum, tmp);
if (((u_long)w & 1) != 0 && mlen >= 1) {
sum <<= 8;
su = *(u_char *)w << 8;
w = (u_short *)((u_char *)w + 1);
mlen--;
byte_swapped = 1;
}
if (((u_long)w & 2) != 0 && mlen >= 2) {
sum += *w++;
mlen -= 2;
}
if (((u_long)w & 4) != 0 && mlen >= 4) {
__asm(
LD32_ADD32(0, cc)
MOP(sum, tmp, w)
);
w += 2;
mlen -= 4;
}
}
/*
* Do as much of the checksum as possible 64 bits at at time.
* In fact, this loop is unrolled to make overhead from
* branches &c small.
*/
for (; mlen >= 64; mlen -= 64) {
__asm(
LD64_ADD32(0, cc)
LD64_ADD32(8, ccc)
LD64_ADD32(16, ccc)
LD64_ADD32(24, ccc)
LD64_ADD32(32, ccc)
LD64_ADD32(40, ccc)
LD64_ADD32(48, ccc)
LD64_ADD32(56, ccc)
MOP(sum, tmp, w)
);
w += 32;
}
if (mlen >= 32) {
__asm(
LD64_ADD32(0, cc)
LD64_ADD32(8, ccc)
LD64_ADD32(16, ccc)
LD64_ADD32(24, ccc)
MOP(sum, tmp, w)
);
w += 16;
mlen -= 32;
}
if (mlen >= 16) {
__asm(
LD64_ADD32(0, cc)
LD64_ADD32(8, ccc)
MOP(sum, tmp, w)
);
w += 8;
mlen -= 16;
}
if (mlen >= 8) {
__asm(
LD64_ADD32(0, cc)
MOP(sum, tmp, w)
);
w += 4;
mlen -= 8;
}
REDUCE(sum, tmp);
while ((mlen -= 2) >= 0)
sum += *w++;
if (byte_swapped) {
sum <<= 8;
byte_swapped = 0;
if (mlen == -1) {
su |= *(u_char *)w;
sum += su;
mlen = 0;
} else
mlen = -1;
} else if (mlen == -1) {
/*
* This mbuf has odd number of bytes.
* There could be a word split between
* this mbuf and the next mbuf.
* Save the last byte (to prepend to next mbuf).
*/
su = *(u_char *)w << 8;
}
}
if (len)
printf("%s: out of data by %d\n", __func__, len);
if (mlen == -1) {
/*
* The last mbuf has odd # of bytes. Follow the
* standard (the odd byte is shifted left by 8 bits).
*/
sum += su & 0xff00;
}
REDUCE(sum, tmp);
return (~sum & 0xffff);
}
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