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freebsd-dev/sys/i386/include/in_cksum.h

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Add an inline function to compute the common-case IP header checksum.
1996-04-18 15:39:27 +00:00
/*-
* 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.
* 4. 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.
*
* from tahoe: in_cksum.c 1.2 86/01/05
* from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91
* from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp
$Id$ -> $FreeBSD$
1999-08-28 01:08:13 +00:00
* $FreeBSD$
Add an inline function to compute the common-case IP header checksum.
1996-04-18 15:39:27 +00:00
*/
#ifndef _MACHINE_IN_CKSUM_H_
#define _MACHINE_IN_CKSUM_H_ 1
netchild's mega-patch to isolate compiler dependencies into a central place. This moves the dependency on GCC's and other compiler's features into the central sys/cdefs.h file, while the individual source files can then refer to #ifdef __COMPILER_FEATURE_FOO where they by now used to refer to #if __GNUC__ > 3.1415 && __BARC__ <= 42. By now, GCC and ICC (the Intel compiler) have been actively tested on IA32 platforms by netchild. Extension to other compilers is supposed to be possible, of course. Submitted by: netchild Reviewed by: various developers on arch@, some time ago
2005-03-02 21:33:29 +00:00
#ifndef _SYS_CDEFS_H_
#error this file needs sys/cdefs.h as a prerequisite
#endif
These files are mpsafe.
2000-11-25 03:01:05 +00:00
/*
* MP safe (alfred)
*/
Add an inline function to compute the common-case IP header checksum.
1996-04-18 15:39:27 +00:00
#include <sys/cdefs.h>
Make in_cksum() a macro call to in_cksum_skip(), since it provides the same functionality. Sharing code should help cache issues. Remove in_cksum_partial, since its not being used, and we now have a way to compute partial checksums on mbuf chains.
2000-05-06 18:18:32 +00:00
#define in_cksum(m, len) in_cksum_skip(m, len, 0)
Add an inline function to compute the common-case IP header checksum.
1996-04-18 15:39:27 +00:00
/*
* It it useful to have an Internet checksum routine which is inlineable
* and optimized specifically for the task of computing IP header checksums
* in the normal case (where there are no options and the header length is
* therefore always exactly five 32-bit words.
*/
netchild's mega-patch to isolate compiler dependencies into a central place. This moves the dependency on GCC's and other compiler's features into the central sys/cdefs.h file, while the individual source files can then refer to #ifdef __COMPILER_FEATURE_FOO where they by now used to refer to #if __GNUC__ > 3.1415 && __BARC__ <= 42. By now, GCC and ICC (the Intel compiler) have been actively tested on IA32 platforms by netchild. Extension to other compilers is supposed to be possible, of course. Submitted by: netchild Reviewed by: various developers on arch@, some time ago
2005-03-02 21:33:29 +00:00
#if defined(__GNUCLIKE_ASM) && !defined(__INTEL_COMPILER)
Add an inline function to compute the common-case IP header checksum.
1996-04-18 15:39:27 +00:00
static __inline u_int
in_cksum_hdr(const struct ip *ip)
{
register u_int sum = 0;
Fix several bugs in the i386 asm statements used to speed up Internet checksumming. These bugs could possibly cause bad code to be generated at elevated optimization levels. First, eliminate the use of preprocessor magic to form the address fields of asm instructions. It hid the actual addresses being referenced from the compiler. Without knowledge of all the data dependencies, the compiler might possibly use optimizations which would result in incorrect code. Use "__asm __volatile" rather than "__asm" for instruction sequences that pass information through the condition codes (the carry bit, in this case). Without __volatile, the compiler might add unrelated code between consecutive __asm instructions, modifying the condition codes. I have seen GCC insert stack pointer adjustments in this way, for example. Unfortunately, GCC doesn't provide a way to specify dependencies on the condition codes. You can specify that they are clobbered, but not that you are going to use them as input. Finally, simplify the LOAD macro. This macro is used as a poor man's prefetch. The simpler version gives the compiler more leeway about just how it performs the prefetch. MFC after: 1 week
2002-06-22 22:35:53 +00:00
Fix a bug in in_cksum_hdr w/o -O. The C code assumes that the carry bit is always kept from the previous operation. However, the pointer indexing requires another add operation. Thus, the carry bit from the first operation is tromped over by the "addl" operation that ends up following it, so the "adcl" that follows that has no effect because the carry bit is cleared before it. The result is checksum failure on received packets. The larger issue is that there isn't any other way of preventing the compiler inserting arbitrary instructions between different __asm statements (and that the commit message in revision 1.13 of in_cksum.h is wrong on this point). From http://developer.apple.com/documentation/DeveloperTools/gcc-3.3/gcc/Extended-Asm.html ---8<---8<---8<--- You can't expect a sequence of volatile asm instructions to remain perfectly consecutive. If you want consecutive output, use a single asm. Also, GCC will perform some optimizations across a volatile asm instruction; GCC does not "forget everything" when it encounters a volatile asm instruction the way some other compilers do. ---8<---8<---8<--- Also, this change also makes the ASM code much easier to read. PR: 69257 Submitted by: Mike Bristow <mike@urgle.com>, Qing Li <qing.li@bluecoat.com>
2004-08-25 18:28:15 +00:00
__asm __volatile (
"addl %1, %0\n"
"adcl %2, %0\n"
"adcl %3, %0\n"
"adcl %4, %0\n"
"adcl %5, %0\n"
"adcl $0, %0"
: "+r" (sum)
: "g" (((const u_int32_t *)ip)[0]),
"g" (((const u_int32_t *)ip)[1]),
"g" (((const u_int32_t *)ip)[2]),
"g" (((const u_int32_t *)ip)[3]),
"g" (((const u_int32_t *)ip)[4])
);
Add an inline function to compute the common-case IP header checksum.
1996-04-18 15:39:27 +00:00
sum = (sum & 0xffff) + (sum >> 16);
if (sum > 0xffff)
sum -= 0xffff;
return ~sum & 0xffff;
}
Add an incremental checksum update routine. Perhaps some i386 assembly guru out there can find a way to take advantage of little-endianness to make this computation more efficient. (I am certain that it can be done, but haven't managed to make it work myself.)
1996-05-23 20:11:48 +00:00
static __inline void
in_cksum_update(struct ip *ip)
{
int __tmpsum;
__tmpsum = (int)ntohs(ip->ip_sum) + 256;
ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
}
Add support for offloading IP/TCP/UDP checksums to NIC hardware which supports them.
2000-03-27 19:14:27 +00:00
static __inline u_short
in_addword(u_short sum, u_short b)
{
Fix several bugs in the i386 asm statements used to speed up Internet checksumming. These bugs could possibly cause bad code to be generated at elevated optimization levels. First, eliminate the use of preprocessor magic to form the address fields of asm instructions. It hid the actual addresses being referenced from the compiler. Without knowledge of all the data dependencies, the compiler might possibly use optimizations which would result in incorrect code. Use "__asm __volatile" rather than "__asm" for instruction sequences that pass information through the condition codes (the carry bit, in this case). Without __volatile, the compiler might add unrelated code between consecutive __asm instructions, modifying the condition codes. I have seen GCC insert stack pointer adjustments in this way, for example. Unfortunately, GCC doesn't provide a way to specify dependencies on the condition codes. You can specify that they are clobbered, but not that you are going to use them as input. Finally, simplify the LOAD macro. This macro is used as a poor man's prefetch. The simpler version gives the compiler more leeway about just how it performs the prefetch. MFC after: 1 week
2002-06-22 22:35:53 +00:00
/* __volatile is necessary because the condition codes are used. */
Fold multiple asm statements into one so that the compiler at a certain optimization level (-march=pentium-mmx for example) does not insert intermediate ops which would trash the carry. Change both sys/i386/i386/in_cksum.c[1] and sys/i386/include/in_cksum.h. To my best understanding the same problem was addressed in rev. 1.16 of src/sys/i386/include/in_cksum.h for just a single function 3y ago. Reviewed by: jhb Submitted by: Zhouyi ZHOU <zhouzhouyi FreeBSD.org> (intial version of [1]) MFC after: 5 days PR: 115678, 69257
2007-10-20 22:18:42 +00:00
__asm __volatile (
"addw %1, %0\n"
"adcw $0, %0"
: "+r" (sum)
: "r" (b)
);
Add support for offloading IP/TCP/UDP checksums to NIC hardware which supports them.
2000-03-27 19:14:27 +00:00
return (sum);
}
static __inline u_short
in_pseudo(u_int sum, u_int b, u_int c)
{
Fix several bugs in the i386 asm statements used to speed up Internet checksumming. These bugs could possibly cause bad code to be generated at elevated optimization levels. First, eliminate the use of preprocessor magic to form the address fields of asm instructions. It hid the actual addresses being referenced from the compiler. Without knowledge of all the data dependencies, the compiler might possibly use optimizations which would result in incorrect code. Use "__asm __volatile" rather than "__asm" for instruction sequences that pass information through the condition codes (the carry bit, in this case). Without __volatile, the compiler might add unrelated code between consecutive __asm instructions, modifying the condition codes. I have seen GCC insert stack pointer adjustments in this way, for example. Unfortunately, GCC doesn't provide a way to specify dependencies on the condition codes. You can specify that they are clobbered, but not that you are going to use them as input. Finally, simplify the LOAD macro. This macro is used as a poor man's prefetch. The simpler version gives the compiler more leeway about just how it performs the prefetch. MFC after: 1 week
2002-06-22 22:35:53 +00:00
/* __volatile is necessary because the condition codes are used. */
Fold multiple asm statements into one so that the compiler at a certain optimization level (-march=pentium-mmx for example) does not insert intermediate ops which would trash the carry. Change both sys/i386/i386/in_cksum.c[1] and sys/i386/include/in_cksum.h. To my best understanding the same problem was addressed in rev. 1.16 of src/sys/i386/include/in_cksum.h for just a single function 3y ago. Reviewed by: jhb Submitted by: Zhouyi ZHOU <zhouzhouyi FreeBSD.org> (intial version of [1]) MFC after: 5 days PR: 115678, 69257
2007-10-20 22:18:42 +00:00
__asm __volatile (
"addl %1, %0\n"
"adcl %2, %0\n"
"adcl $0, %0"
: "+r" (sum)
: "g" (b),
"g" (c)
);
Add support for offloading IP/TCP/UDP checksums to NIC hardware which supports them.
2000-03-27 19:14:27 +00:00
sum = (sum & 0xffff) + (sum >> 16);
if (sum > 0xffff)
sum -= 0xffff;
return (sum);
}
Add an inline function to compute the common-case IP header checksum.
1996-04-18 15:39:27 +00:00
#else
Add an incremental checksum update routine. Perhaps some i386 assembly guru out there can find a way to take advantage of little-endianness to make this computation more efficient. (I am certain that it can be done, but haven't managed to make it work myself.)
1996-05-23 20:11:48 +00:00
#define in_cksum_update(ip) \
do { \
int __tmpsum; \
__tmpsum = (int)ntohs(ip->ip_sum) + 256; \
ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \
} while(0)
Add an inline function to compute the common-case IP header checksum.
1996-04-18 15:39:27 +00:00
#endif
Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL" is an application space macro and the applications are supposed to be free to use it as they please (but cannot). This is consistant with the other BSD's who made this change quite some time ago. More commits to come.
1999-12-29 04:46:21 +00:00
#ifdef _KERNEL
netchild's mega-patch to isolate compiler dependencies into a central place. This moves the dependency on GCC's and other compiler's features into the central sys/cdefs.h file, while the individual source files can then refer to #ifdef __COMPILER_FEATURE_FOO where they by now used to refer to #if __GNUC__ > 3.1415 && __BARC__ <= 42. By now, GCC and ICC (the Intel compiler) have been actively tested on IA32 platforms by netchild. Extension to other compilers is supposed to be possible, of course. Submitted by: netchild Reviewed by: various developers on arch@, some time ago
2005-03-02 21:33:29 +00:00
#if !defined(__GNUCLIKE_ASM) || defined(__INTEL_COMPILER)
These are changes to allow to use the Intel C/C++ compiler (lang/icc) to build the kernel. It doesn't affect the operation if gcc. Most of the changes are just adding __INTEL_COMPILER to #ifdef's, as icc v8 may define __GNUC__ some parts may look strange but are necessary. Additional changes: - in_cksum.[ch]: * use a generic C version instead of the assembly version in the !gcc case (ASM code breaks with the optimizations icc does) -> no bad checksums with an icc compiled kernel Help from: andre, grehan, das Stolen from: alpha version via ppc version The entire checksum code should IMHO be replaced with the DragonFly version (because it isn't guaranteed future revisions of gcc will include similar optimizations) as in: ---snip--- Revision Changes Path 1.12 +1 -0 src/sys/conf/files.i386 1.4 +142 -558 src/sys/i386/i386/in_cksum.c 1.5 +33 -69 src/sys/i386/include/in_cksum.h 1.5 +2 -0 src/sys/netinet/igmp.c 1.6 +0 -1 src/sys/netinet/in.h 1.6 +2 -0 src/sys/netinet/ip_icmp.c 1.4 +3 -4 src/contrib/ipfilter/ip_compat.h 1.3 +1 -2 src/sbin/natd/icmp.c 1.4 +0 -1 src/sbin/natd/natd.c 1.48 +1 -0 src/sys/conf/files 1.2 +0 -1 src/sys/conf/files.amd64 1.13 +0 -1 src/sys/conf/files.i386 1.5 +0 -1 src/sys/conf/files.pc98 1.7 +1 -1 src/sys/contrib/ipfilter/netinet/fil.c 1.10 +2 -3 src/sys/contrib/ipfilter/netinet/ip_compat.h 1.10 +1 -1 src/sys/contrib/ipfilter/netinet/ip_fil.c 1.7 +1 -1 src/sys/dev/netif/txp/if_txp.c 1.7 +1 -1 src/sys/net/ip_mroute/ip_mroute.c 1.7 +1 -2 src/sys/net/ipfw/ip_fw2.c 1.6 +1 -2 src/sys/netinet/igmp.c 1.4 +158 -116 src/sys/netinet/in_cksum.c 1.6 +1 -1 src/sys/netinet/ip_gre.c 1.7 +1 -2 src/sys/netinet/ip_icmp.c 1.10 +1 -1 src/sys/netinet/ip_input.c 1.10 +1 -2 src/sys/netinet/ip_output.c 1.13 +1 -2 src/sys/netinet/tcp_input.c 1.9 +1 -2 src/sys/netinet/tcp_output.c 1.10 +1 -1 src/sys/netinet/tcp_subr.c 1.10 +1 -1 src/sys/netinet/tcp_syncache.c 1.9 +1 -2 src/sys/netinet/udp_usrreq.c 1.5 +1 -2 src/sys/netinet6/ipsec.c 1.5 +1 -2 src/sys/netproto/ipsec/ipsec.c 1.5 +1 -1 src/sys/netproto/ipsec/ipsec_input.c 1.4 +1 -2 src/sys/netproto/ipsec/ipsec_output.c and finally remove sys/i386/i386 in_cksum.c sys/i386/include in_cksum.h ---snip--- - endian.h: * DTRT in C++ mode - quad.h: * we don't use gcc v1 anymore, remove support for it Suggested by: bde (long ago) - assym.h: * avoid zero-length arrays (remove dependency on a gcc specific feature) This change changes the contents of the object file, but as it's only used to generate some values for a header, and the generator knows how to handle this, there's no impact in the gcc case. Explained by: bde Submitted by: Marius Strobl <marius@alchemy.franken.de> - aicasm.c: * minor change to teach it about the way icc spells "-nostdinc" Not approved by: gibbs (no reply to my mail) - bump __FreeBSD_version (lang/icc needs to know about the changes) Incarnations of this patch survive gcc compiles since a loooong time, I use it on my desktop. An icc compiled kernel works since Nov. 2003 (exceptions: snd_* if used as modules), it survives a build of the entire ports collection with icc. Parts of this commit contains suggestions or submissions from Marius Strobl <marius@alchemy.franken.de>. Reviewed by: -arch Submitted by: netchild
2004-03-12 21:45:33 +00:00
u_int in_cksum_hdr(const struct ip *ip);
u_short in_addword(u_short sum, u_short b);
u_short in_pseudo(u_int sum, u_int b, u_int c);
#endif
u_short in_cksum_skip(struct mbuf *m, int len, int skip);
Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL" is an application space macro and the applications are supposed to be free to use it as they please (but cannot). This is consistant with the other BSD's who made this change quite some time ago. More commits to come.
1999-12-29 04:46:21 +00:00
#endif /* _KERNEL */
Fix all areas of the system (or at least all those in LINT) to avoid storing socket addresses in mbufs. (Socket buffers are the one exception.) A number of kernel APIs needed to get fixed in order to make this happen. Also, fix three protocol families which kept PCBs in mbufs to not malloc them instead. Delete some old compatibility cruft while we're at it, and add some new routines in the in_cksum family.
1997-08-16 19:16:27 +00:00
Add an inline function to compute the common-case IP header checksum.
1996-04-18 15:39:27 +00:00
#endif /* _MACHINE_IN_CKSUM_H_ */
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