Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932792AbZD3PqA (ORCPT ); Thu, 30 Apr 2009 11:46:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932362AbZD3PmV (ORCPT ); Thu, 30 Apr 2009 11:42:21 -0400 Received: from moutng.kundenserver.de ([212.227.126.187]:64325 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932285AbZD3PmF (ORCPT ); Thu, 30 Apr 2009 11:42:05 -0400 Message-Id: In-Reply-To: References: From: Arnd Bergmann Date: Tue, 31 Mar 2009 15:30:31 +0200 Subject: [PATCH 17/27] add generic lib/checksum.c Cc: linux-arch@vger.kernel.org, Michal Simek , Remis Lima Baima , linux-kernel@vger.kernel.org X-Provags-ID: V01U2FsdGVkX1+8Z9j6/qUpsXkCBHPZ4fBtwbovQ1utA3pJyMQ Nt2CjvqOsVKll6Xg3WzPKdWeKaadnyQxJBrt7/+qOXYO9XGJQs Qqta/XysQ0pqAwJhtf+0w== To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8742 Lines: 317 Add a generic (unoptimized) implementation of checksum.c in pure C for use by all architectures. Based on microblaze code by Michal Simek Cc: Michal Simek Signed-off-by: Arnd Bergmann Signed-off-by: Remis Lima Baima --- include/asm-generic/checksum.h | 79 +++++++++++++++++ lib/Makefile | 2 + lib/checksum.c | 188 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 269 insertions(+), 0 deletions(-) create mode 100644 include/asm-generic/checksum.h create mode 100644 lib/checksum.c diff --git a/include/asm-generic/checksum.h b/include/asm-generic/checksum.h new file mode 100644 index 0000000..4647c76 --- /dev/null +++ b/include/asm-generic/checksum.h @@ -0,0 +1,79 @@ +#ifndef __ASM_GENERIC_CHECKSUM_H +#define __ASM_GENERIC_CHECKSUM_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 + */ +extern __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 + */ +extern __wsum csum_partial_copy(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); + +#define csum_partial_copy_nocheck(src, dst, len, sum) \ + csum_partial_copy((src), (dst), (len), (sum)) + +/* + * This is a version of ip_compute_csum() optimized for IP headers, + * which always checksum on 4 octet boundaries. + */ +extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl); + +/* + * Fold a partial checksum + */ +static inline __sum16 csum_fold(__wsum csum) +{ + u32 sum = (__force u32)csum; + sum = (sum & 0xffff) + (sum >> 16); + sum = (sum & 0xffff) + (sum >> 16); + return (__force __sum16)~sum; +} + +#ifndef csum_tcpudp_nofold +/* + * computes the checksum of the TCP/UDP pseudo-header + * returns a 16-bit checksum, already complemented + */ +extern __wsum +csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len, + unsigned short proto, __wsum sum); +#endif + +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); + +#endif /* __ASM_GENERIC_CHECKSUM_H */ diff --git a/lib/Makefile b/lib/Makefile index 33a40e4..b6869e1 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -92,6 +92,8 @@ obj-$(CONFIG_NLATTR) += nlattr.o obj-$(CONFIG_DMA_API_DEBUG) += dma-debug.o +obj-$(CONFIG_GENERIC_CSUM) += checksum.o + hostprogs-y := gen_crc32table clean-files := crc32table.h diff --git a/lib/checksum.c b/lib/checksum.c new file mode 100644 index 0000000..4f80a4d --- /dev/null +++ b/lib/checksum.c @@ -0,0 +1,188 @@ +/* + * arch/microblaze/lib/checksum.c + * + * Copyright (C) 2008 Michal Simek + * + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * IP/TCP/UDP checksumming routines + * + * Authors: Jorge Cwik, + * Arnt Gulbrandsen, + * Tom May, + * Andreas Schwab, + * Lots of code moved from tcp.c and ip.c; see those files + * for more names. + * + * 03/02/96 Jes Sorensen, Andreas Schwab, Roman Hodek: + * Fixed some nasty bugs, causing some horrible crashes. + * A: At some points, the sum (%0) was used as + * length-counter instead of the length counter + * (%1). Thanks to Roman Hodek for pointing this out. + * B: GCC seems to mess up if one uses too many + * data-registers to hold input values and one tries to + * specify d0 and d1 as scratch registers. Letting gcc choose these + * registers itself solves the problem. + * + * 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. + */ + +/* Revised by Kenneth Albanowski for m68knommu. Basic problem: unaligned access + kills, so most of the assembly has to go. */ + +#include +#include +#include +#include + +static inline unsigned short from32to16(unsigned long x) +{ + /* add up 16-bit and 16-bit for 16+c bit */ + x = (x & 0xffff) + (x >> 16); + /* add up carry.. */ + x = (x & 0xffff) + (x >> 16); + return x; +} + +static unsigned int do_csum(const unsigned char *buff, int len) +{ + int odd, count; + unsigned long result = 0; + + if (len <= 0) + goto out; + odd = 1 & (unsigned long) buff; + if (odd) { + result = *buff; + len--; + buff++; + } + count = len >> 1; /* nr of 16-bit words.. */ + if (count) { + if (2 & (unsigned long) buff) { + result += *(unsigned short *) buff; + count--; + len -= 2; + buff += 2; + } + count >>= 1; /* nr of 32-bit words.. */ + if (count) { + unsigned long carry = 0; + do { + unsigned long w = *(unsigned long *) buff; + count--; + buff += 4; + result += carry; + result += w; + carry = (w > result); + } while (count); + result += carry; + result = (result & 0xffff) + (result >> 16); + } + if (len & 2) { + result += *(unsigned short *) buff; + buff += 2; + } + } + if (len & 1) + result += (*buff << 8); + result = from32to16(result); + if (odd) + result = ((result >> 8) & 0xff) | ((result & 0xff) << 8); +out: + return result; +} + +/* + * This is a version of ip_compute_csum() optimized for IP headers, + * which always checksum on 4 octet boundaries. + */ +__sum16 ip_fast_csum(const void *iph, unsigned int ihl) +{ + return ~do_csum(iph, ihl*4); +} + +/* + * 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) +{ + unsigned int result = do_csum(buff, len); + + /* add in old sum, and carry.. */ + result += sum; + if (sum > result) + result += 1; + return result; +} +EXPORT_SYMBOL(csum_partial); + +/* + * this routine is used for miscellaneous IP-like checksums, mainly + * in icmp.c + */ +__sum16 ip_compute_csum(const void *buff, int len) +{ + return ~do_csum(buff, len); +} +EXPORT_SYMBOL(ip_compute_csum); + +/* + * copy from fs while checksumming, otherwise like csum_partial + */ +__wsum +csum_partial_copy_from_user(const void __user *src, void *dst, int len, + __wsum sum, int *csum_err) +{ + if (csum_err) + *csum_err = 0; + memcpy(dst, src, len); + return csum_partial(dst, len, sum); +} +EXPORT_SYMBOL(csum_partial_copy_from_user); + +/* + * copy from ds while checksumming, otherwise like csum_partial + */ +__wsum +csum_partial_copy(const void *src, void *dst, int len, __wsum sum) +{ + memcpy(dst, src, len); + return csum_partial(dst, len, sum); +} +EXPORT_SYMBOL(csum_partial_copy); + +#ifndef csum_tcpudp_nofold +__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, + unsigned short len, + unsigned short proto, + __wsum sum) +{ + unsigned long long s = (__force u32)sum; + + s += (__force u32)saddr; + s += (__force u32)daddr; +#ifdef __BIG_ENDIAN + s += proto + len; +#else + s += (proto + len) << 8; +#endif + s += (s >> 32); + return (__force __wsum)s; +} +EXPORT_SYMBOL(csum_tcpudp_nofold); +#endif -- 1.5.6.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/