/* $OpenBSD: in_cksum.s,v 1.7 2005/05/21 19:13:55 brad Exp $ */
/* $NetBSD: in_cksum.S,v 1.2 2003/08/07 16:27:54 agc Exp $ */
/*-
* Copyright (c) 1998, 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Charles M. Hannum.
*
* 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 by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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) 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.
*/
#include <machine/asm.h>
#include "assym.h"
/* LINTSTUB: include <sys/types.h> */
/* LINTSTUB: include <machine/param.h> */
/* LINTSTUB: include <sys/mbuf.h> */
/* LINTSTUB: include <netinet/in.h> */
/*
* Checksum routine for Internet Protocol family headers.
*
* in_cksum(m, len)
*
* Registers used:
* %eax = sum
* %ebx = m->m_data
* %cl = rotation count to unswap
* %edx = m->m_len
* %ebp = m
* %esi = len
*/
#define SWAP \
roll $8, %eax ; \
xorb $8, %cl
#define UNSWAP \
roll %cl, %eax
#define MOP \
adcl $0, %eax
#define ADVANCE(n) \
leal n(%ebx), %ebx ; \
leal -n(%edx), %edx ; \
#define ADDBYTE \
SWAP ; \
addb (%ebx), %ah
#define ADDWORD \
addw (%ebx), %ax
#define ADD(n) \
addl n(%ebx), %eax
#define ADC(n) \
adcl n(%ebx), %eax
#define REDUCE \
movzwl %ax, %edx ; \
shrl $16, %eax ; \
addw %dx, %ax ; \
adcw $0, %ax
/* LINTSTUB: Func: int in4_cksum(struct mbuf *m, u_int8_t nxt, int off, int len) */
ENTRY(in4_cksum)
pushl %ebp
pushl %ebx
pushl %esi
movl 16(%esp), %ebp
movzbl 20(%esp), %eax /* sum = nxt */
movl 24(%esp), %edx /* %edx = off */
movl 28(%esp), %esi /* %esi = len */
testl %eax, %eax
jz .Lmbuf_loop_0 /* skip if nxt == 0 */
movl M_DATA(%ebp), %ebx
addl %esi, %eax /* sum += len */
shll $8, %eax /* sum = htons(sum) */
ADD(IP_SRC) /* sum += ip->ip_src */
ADC(IP_DST) /* sum += ip->ip_dst */
MOP
.Lmbuf_loop_0:
testl %ebp, %ebp
jz .Lout_of_mbufs
movl M_DATA(%ebp), %ebx /* %ebx = m_data */
movl M_LEN(%ebp), %ecx /* %ecx = m_len */
movl M_NEXT(%ebp), %ebp
subl %ecx, %edx /* %edx = off - m_len */
jnb .Lmbuf_loop_0
addl %edx, %ebx /* %ebx = m_data + off - m_len */
negl %edx /* %edx = m_len - off */
addl %ecx, %ebx /* %ebx = m_data + off */
xorb %cl, %cl
/*
* The len == 0 case is handled really inefficiently, by going through
* the whole short_mbuf path once to get back to mbuf_loop_1 -- but
* this case never happens in practice, so it's sufficient that it
* doesn't explode.
*/
jmp .Lin4_entry
/* LINTSTUB: Func: int in_cksum(struct mbuf *m, int len) */
ENTRY(in_cksum)
pushl %ebp
pushl %ebx
pushl %esi
movl 16(%esp), %ebp
movl 20(%esp), %esi
xorl %eax, %eax
xorb %cl, %cl
.Lmbuf_loop_1:
testl %esi, %esi
jz .Ldone
.Lmbuf_loop_2:
testl %ebp, %ebp
jz .Lout_of_mbufs
movl M_DATA(%ebp), %ebx
movl M_LEN(%ebp), %edx
movl M_NEXT(%ebp), %ebp
.Lin4_entry:
cmpl %esi, %edx
jbe 1f
movl %esi, %edx
1:
subl %edx, %esi
cmpl $32, %edx
jb .Lshort_mbuf
testb $3, %bl
jz .Ldword_aligned
testb $1, %bl
jz .Lbyte_aligned
ADDBYTE
ADVANCE(1)
MOP
testb $2, %bl
jz .Lword_aligned
.Lbyte_aligned:
ADDWORD
ADVANCE(2)
MOP
.Lword_aligned:
.Ldword_aligned:
testb $4, %bl
jnz .Lqword_aligned
ADD(0)
ADVANCE(4)
MOP
.Lqword_aligned:
testb $8, %bl
jz .Loword_aligned
ADD(0)
ADC(4)
ADVANCE(8)
MOP
.Loword_aligned:
subl $128, %edx
jb .Lfinished_128
.Lloop_128:
ADD(12)
ADC(0)
ADC(4)
ADC(8)
ADC(28)
ADC(16)
ADC(20)
ADC(24)
ADC(44)
ADC(32)
ADC(36)
ADC(40)
ADC(60)
ADC(48)
ADC(52)
ADC(56)
ADC(76)
ADC(64)
ADC(68)
ADC(72)
ADC(92)
ADC(80)
ADC(84)
ADC(88)
ADC(108)
ADC(96)
ADC(100)
ADC(104)
ADC(124)
ADC(112)
ADC(116)
ADC(120)
leal 128(%ebx), %ebx
MOP
subl $128, %edx
jnb .Lloop_128
.Lfinished_128:
subl $32-128, %edx
jb .Lfinished_32
.Lloop_32:
ADD(12)
ADC(0)
ADC(4)
ADC(8)
ADC(28)
ADC(16)
ADC(20)
ADC(24)
leal 32(%ebx), %ebx
MOP
subl $32, %edx
jnb .Lloop_32
.Lfinished_32:
.Lshort_mbuf:
testb $16, %dl
jz .Lfinished_16
ADD(12)
ADC(0)
ADC(4)
ADC(8)
leal 16(%ebx), %ebx
MOP
.Lfinished_16:
testb $8, %dl
jz .Lfinished_8
ADD(0)
ADC(4)
leal 8(%ebx), %ebx
MOP
.Lfinished_8:
testb $4, %dl
jz .Lfinished_4
ADD(0)
leal 4(%ebx), %ebx
MOP
.Lfinished_4:
testb $3, %dl
jz .Lmbuf_loop_1
testb $2, %dl
jz .Lfinished_2
ADDWORD
leal 2(%ebx), %ebx
MOP
testb $1, %dl
jz .Lfinished_1
.Lfinished_2:
ADDBYTE
MOP
.Lfinished_1:
.Lmbuf_done:
testl %esi, %esi
jnz .Lmbuf_loop_2
.Ldone:
UNSWAP
REDUCE
notw %ax
.Lreturn:
popl %esi
popl %ebx
popl %ebp
ret
.Lout_of_mbufs:
pushl $1f
call _C_LABEL(printf)
leal 4(%esp), %esp
jmp .Lreturn
1:
.asciz "cksum: out of data\n"
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