NetBSD-5.0.2/sys/arch/powerpc/powerpc/in_cksum.c
/* $NetBSD: in_cksum.c,v 1.10 2005/12/24 23:24:01 perry Exp $ */
/*
* Copyright 2001 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Simon Burge and Eduardo Horvath for Wasabi Systems, Inc.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
* 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: in_cksum.c,v 1.10 2005/12/24 23:24:01 perry Exp $");
#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/systm.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_var.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.
*
* PowerPC version.
*/
#define REDUCE1 sum = (sum & 0xffff) + (sum >> 16)
/* Two REDUCE1s is faster than REDUCE1; if (sum > 65535) sum -= 65536; */
#define REDUCE { REDUCE1; REDUCE1; }
static inline int
in_cksum_internal(struct mbuf *m, int off, int len, u_int sum)
{
uint8_t *w;
int mlen = 0;
int byte_swapped = 0;
int n;
union {
uint8_t c[2];
uint16_t s;
} s_util;
for (;m && len; m = m->m_next) {
if (m->m_len == 0)
continue;
w = mtod(m, uint8_t *) + off;
/*
* 'off' can only be non-zero on the first pass of this
* loop when mlen != -1, so we don't need to worry about
* 'off' in the if clause below.
*/
if (mlen == -1) {
/*
* The first byte of this mbuf is the continuation
* of a word spanning between this mbuf and the
* last mbuf.
*
* s_util.c[0] is already saved when scanning previous
* mbuf.
*/
s_util.c[1] = *w++;
sum += s_util.s;
mlen = m->m_len - 1;
len--;
} else {
mlen = m->m_len - off;
off = 0;
}
if (len < mlen)
mlen = len;
len -= mlen;
/*
* Force to a word boundary.
*/
if ((3 & (long) w) && (mlen > 0)) {
if ((1 & (long) w)) {
REDUCE;
sum <<= 8;
s_util.c[0] = *w++;
mlen--;
byte_swapped = 1;
}
if ((2 & (long) w) && (mlen > 1)) {
/*
* Since the `sum' may contain full 32 bit
* value, we can't simply add any value.
*/
__asm volatile(
"lhz 7,0(%1);" /* load current data
half word */
"addc %0,%0,7;" /* add to sum */
"addze %0,%0;" /* add carry bit */
: "+r"(sum)
: "b"(w)
: "7"); /* clobber r7 */
w += 2;
mlen -= 2;
}
}
if (mlen >= 64) {
n = mlen >> 6;
__asm volatile(
"addic 0,0,0;" /* clear carry */
"mtctr %1;" /* load loop count */
"1:"
"lwz 7,4(%2);" /* load current data
word */
"lwz 8,8(%2);"
"lwz 9,12(%2);"
"lwz 10,16(%2);"
"adde %0,%0,7;" /* add to sum */
"adde %0,%0,8;"
"adde %0,%0,9;"
"adde %0,%0,10;"
"lwz 7,20(%2);"
"lwz 8,24(%2);"
"lwz 9,28(%2);"
"lwz 10,32(%2);"
"adde %0,%0,7;"
"adde %0,%0,8;"
"adde %0,%0,9;"
"adde %0,%0,10;"
"lwz 7,36(%2);"
"lwz 8,40(%2);"
"lwz 9,44(%2);"
"lwz 10,48(%2);"
"adde %0,%0,7;"
"adde %0,%0,8;"
"adde %0,%0,9;"
"adde %0,%0,10;"
"lwz 7,52(%2);"
"lwz 8,56(%2);"
"lwz 9,60(%2);"
"lwzu 10,64(%2);"
"adde %0,%0,7;"
"adde %0,%0,8;"
"adde %0,%0,9;"
"adde %0,%0,10;"
"bdnz 1b;" /* loop */
"addze %0,%0;" /* add carry bit */
: "+r"(sum)
: "r"(n), "b"(w - 4)
: "7", "8", "9", "10"); /* clobber r7, r8, r9,
r10 */
w += n * 64;
mlen -= n * 64;
}
if (mlen >= 8) {
n = mlen >> 3;
__asm volatile(
"addic 0,0,0;" /* clear carry */
"mtctr %1;" /* load loop count */
"1:"
"lwz 7,4(%2);" /* load current data
word */
"lwzu 8,8(%2);"
"adde %0,%0,7;" /* add to sum */
"adde %0,%0,8;"
"bdnz 1b;" /* loop */
"addze %0,%0;" /* add carry bit */
: "+r"(sum)
: "r"(n), "b"(w - 4)
: "7", "8"); /* clobber r7, r8 */
w += n * 8;
mlen -= n * 8;
}
if (mlen == 0 && byte_swapped == 0)
continue;
REDUCE;
while ((mlen -= 2) >= 0) {
sum += *(uint16_t *)w;
w += 2;
}
if (byte_swapped) {
REDUCE;
sum <<= 8;
byte_swapped = 0;
if (mlen == -1) {
s_util.c[1] = *w;
sum += s_util.s;
mlen = 0;
} else
mlen = -1;
} else if (mlen == -1)
s_util.c[0] = *w;
}
if (len)
printf("cksum: out of data\n");
if (mlen == -1) {
/* The last mbuf has odd # of bytes. Follow the
standard (the odd byte may be shifted left by 8 bits
or not as determined by endian-ness of the machine) */
s_util.c[1] = 0;
sum += s_util.s;
}
REDUCE;
return (~sum & 0xffff);
}
int
in_cksum(struct mbuf *m, int len)
{
return (in_cksum_internal(m, 0, len, 0));
}
int
in4_cksum(struct mbuf *m, uint8_t nxt, int off, int len)
{
uint16_t *w;
u_int sum = 0;
union {
struct ipovly ipov;
u_int16_t w[10];
} u;
if (nxt != 0) {
/* pseudo header */
memset(&u.ipov, 0, sizeof(u.ipov));
u.ipov.ih_len = htons(len);
u.ipov.ih_pr = nxt;
u.ipov.ih_src = mtod(m, struct ip *)->ip_src;
u.ipov.ih_dst = mtod(m, struct ip *)->ip_dst;
w = u.w;
/* assumes sizeof(ipov) == 20 */
sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3]; sum += w[4];
sum += w[5]; sum += w[6]; sum += w[7]; sum += w[8]; sum += w[9];
}
/* skip unnecessary part */
while (m && off > 0) {
if (m->m_len > off)
break;
off -= m->m_len;
m = m->m_next;
}
return (in_cksum_internal(m, off, len, sum));
}