Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751376AbXB0BfV (ORCPT ); Mon, 26 Feb 2007 20:35:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751343AbXB0BfV (ORCPT ); Mon, 26 Feb 2007 20:35:21 -0500 Received: from smtp.osdl.org ([65.172.181.24]:42290 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751376AbXB0BfT (ORCPT ); Mon, 26 Feb 2007 20:35:19 -0500 Date: Mon, 26 Feb 2007 17:35:17 -0800 From: Stephen Hemminger To: Andrew Morton Cc: linux-kernel@vger.kernel.org Subject: [PATCH] udivdi3: 64 bit divide Message-ID: <20070226173517.66bf0fec@freekitty> Organization: Linux Foundation X-Mailer: Sylpheed-Claws 2.5.0-rc3 (GTK+ 2.10.6; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10622 Lines: 427 The kernel already has several implmentations and usages of 64 by 64 bit divide. Although it is significantly slower, there are places that need it so provide one generic version using scaling, and allow existing platform versions to continue. This looks like good -mm material. Tested on x86_64 and i386. Signed-off-by: Stephen Hemminger --- arch/alpha/Kconfig | 4 ++++ arch/arm/Kconfig | 4 ++++ arch/arm26/Kconfig | 4 ++++ arch/avr32/Kconfig | 4 ++++ arch/cris/Kconfig | 4 ++++ arch/frv/Kconfig | 4 ++++ arch/h8300/Kconfig | 4 ++++ arch/i386/Kconfig | 4 ++++ arch/m32r/Kconfig | 4 ++++ arch/m68k/Kconfig | 4 ++++ arch/m68knommu/Kconfig | 4 ++++ arch/mips/Kconfig | 4 ++++ arch/parisc/Kconfig | 4 ++++ arch/powerpc/Kconfig | 4 ++++ arch/ppc/Kconfig | 4 ++++ arch/s390/Kconfig | 4 ++++ arch/sh64/Kconfig | 4 ++++ arch/v850/Kconfig | 3 +++ arch/xtensa/Kconfig | 4 ++++ lib/Makefile | 1 + lib/udivdi3.c | 37 +++++++++++++++++++++++++++++++++++++ net/ipv4/tcp_cubic.c | 24 +----------------------- net/netfilter/xt_connbytes.c | 19 +------------------ 23 files changed, 115 insertions(+), 41 deletions(-) --- pktgen.orig/net/ipv4/tcp_cubic.c 2007-02-26 13:40:08.000000000 -0800 +++ pktgen/net/ipv4/tcp_cubic.c 2007-02-26 14:31:41.000000000 -0800 @@ -51,7 +51,6 @@ module_param(tcp_friendliness, int, 0644); MODULE_PARM_DESC(tcp_friendliness, "turn on/off tcp friendliness"); -#include /* BIC TCP Parameters */ struct bictcp { @@ -93,27 +92,6 @@ tcp_sk(sk)->snd_ssthresh = initial_ssthresh; } -/* 64bit divisor, dividend and result. dynamic precision */ -static inline u_int64_t div64_64(u_int64_t dividend, u_int64_t divisor) -{ - u_int32_t d = divisor; - - if (divisor > 0xffffffffULL) { - unsigned int shift = fls(divisor >> 32); - - d = divisor >> shift; - dividend >>= shift; - } - - /* avoid 64 bit division if possible */ - if (dividend >> 32) - do_div(dividend, d); - else - dividend = (uint32_t) dividend / d; - - return dividend; -} - /* * calculate the cubic root of x using Newton-Raphson */ @@ -134,7 +112,7 @@ */ do { x1 = x; - x = (2 * x + (uint32_t) div64_64(a, x*x)) / 3; + x = (2 * x + (u32) (a / (x*x))) / 3; } while (abs(x1 - x) > 1); return x; --- pktgen.orig/net/netfilter/xt_connbytes.c 2007-02-26 13:40:08.000000000 -0800 +++ pktgen/net/netfilter/xt_connbytes.c 2007-02-26 14:29:13.000000000 -0800 @@ -16,7 +16,6 @@ #include #include -#include #include MODULE_LICENSE("GPL"); @@ -24,22 +23,6 @@ MODULE_DESCRIPTION("iptables match for matching number of pkts/bytes per connection"); MODULE_ALIAS("ipt_connbytes"); -/* 64bit divisor, dividend and result. dynamic precision */ -static u_int64_t div64_64(u_int64_t dividend, u_int64_t divisor) -{ - u_int32_t d = divisor; - - if (divisor > 0xffffffffULL) { - unsigned int shift = fls(divisor >> 32); - - d = divisor >> shift; - dividend >>= shift; - } - - do_div(dividend, d); - return dividend; -} - static int match(const struct sk_buff *skb, const struct net_device *in, @@ -106,7 +89,7 @@ break; } if (pkts != 0) - what = div64_64(bytes, pkts); + what = bytes / pkts; break; } --- pktgen.orig/lib/Makefile 2007-02-26 13:40:08.000000000 -0800 +++ pktgen/lib/Makefile 2007-02-26 14:17:31.000000000 -0800 @@ -28,6 +28,7 @@ lib-$(CONFIG_SEMAPHORE_SLEEPERS) += semaphore-sleepers.o lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o +obj-$(CONFIG_GENERIC_UDIVDI3) += udivdi3.o obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o obj-$(CONFIG_PLIST) += plist.o obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o --- pktgen.orig/arch/alpha/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/alpha/Kconfig 2007-02-26 13:54:35.000000000 -0800 @@ -33,6 +33,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_FIND_NEXT_BIT bool default y --- pktgen.orig/arch/arm/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/arm/Kconfig 2007-02-26 13:54:57.000000000 -0800 @@ -90,6 +90,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_HWEIGHT bool default y --- pktgen.orig/arch/arm26/Kconfig 2007-02-26 13:48:46.000000000 -0800 +++ pktgen/arch/arm26/Kconfig 2007-02-26 13:55:24.000000000 -0800 @@ -49,6 +49,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_HWEIGHT bool default y --- pktgen.orig/arch/avr32/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/avr32/Kconfig 2007-02-26 13:55:39.000000000 -0800 @@ -53,6 +53,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_BUST_SPINLOCK bool --- pktgen.orig/arch/cris/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/cris/Kconfig 2007-02-26 13:55:53.000000000 -0800 @@ -28,6 +28,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_FIND_NEXT_BIT bool default y --- pktgen.orig/arch/frv/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/frv/Kconfig 2007-02-26 13:56:09.000000000 -0800 @@ -53,6 +53,10 @@ bool default y +config GENERIC_UDIVDI3 + bool + default y + mainmenu "Fujitsu FR-V Kernel Configuration" source "init/Kconfig" --- pktgen.orig/arch/h8300/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/h8300/Kconfig 2007-02-26 13:56:20.000000000 -0800 @@ -41,6 +41,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_FIND_NEXT_BIT bool default y --- pktgen.orig/arch/i386/Kconfig 2007-02-26 14:01:59.000000000 -0800 +++ pktgen/arch/i386/Kconfig 2007-02-26 14:02:28.000000000 -0800 @@ -75,6 +75,10 @@ bool default y +config GENERIC_UDIVDI3 + bool + default y + config ARCH_MAY_HAVE_PC_FDC bool default y --- pktgen.orig/arch/m32r/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/m32r/Kconfig 2007-02-26 13:56:43.000000000 -0800 @@ -229,6 +229,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_FIND_NEXT_BIT bool default y --- pktgen.orig/arch/m68k/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/m68k/Kconfig 2007-02-26 13:56:56.000000000 -0800 @@ -25,6 +25,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_HWEIGHT bool default y --- pktgen.orig/arch/m68knommu/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/m68knommu/Kconfig 2007-02-26 13:57:05.000000000 -0800 @@ -37,6 +37,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_FIND_NEXT_BIT bool default y --- pktgen.orig/arch/mips/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/mips/Kconfig 2007-02-26 13:57:13.000000000 -0800 @@ -843,6 +843,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_FIND_NEXT_BIT bool default y --- pktgen.orig/arch/parisc/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/parisc/Kconfig 2007-02-26 13:57:21.000000000 -0800 @@ -33,6 +33,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_FIND_NEXT_BIT bool default y --- pktgen.orig/arch/powerpc/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/powerpc/Kconfig 2007-02-26 13:57:31.000000000 -0800 @@ -49,6 +49,10 @@ bool default y if 64BIT +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_HWEIGHT bool default y --- pktgen.orig/arch/ppc/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/ppc/Kconfig 2007-02-26 13:57:44.000000000 -0800 @@ -27,6 +27,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_HWEIGHT bool default y --- pktgen.orig/arch/s390/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/s390/Kconfig 2007-02-26 13:57:53.000000000 -0800 @@ -34,6 +34,10 @@ bool default n +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_HWEIGHT bool default y --- pktgen.orig/arch/sh64/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/sh64/Kconfig 2007-02-26 14:00:32.000000000 -0800 @@ -21,6 +21,10 @@ bool default y +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_FIND_NEXT_BIT bool default y --- pktgen.orig/arch/v850/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/v850/Kconfig 2007-02-26 13:59:29.000000000 -0800 @@ -19,6 +19,9 @@ config RWSEM_XCHGADD_ALGORITHM bool default n +config GENERIC_UDIVDI3 + bool + default y config GENERIC_FIND_NEXT_BIT bool default y --- pktgen.orig/arch/xtensa/Kconfig 2007-02-26 13:51:29.000000000 -0800 +++ pktgen/arch/xtensa/Kconfig 2007-02-26 13:59:45.000000000 -0800 @@ -26,6 +26,10 @@ bool default y +config GENERIC_UDIVDI3 + bool + default y + config GENERIC_FIND_NEXT_BIT bool default y --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ pktgen/lib/udivdi3.c 2007-02-26 14:14:13.000000000 -0800 @@ -0,0 +1,37 @@ +/* + * Generic C version of full 64 bit by 64 bit division + * Extracted from version used by netfilter connection tracking + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * Code generated for this function might be very inefficient + * for some CPUs, can be overridden by linking arch-specific + * assembly versions such as arch/sparc/lib/udivdi.S + */ +#include +#include +#include + +uint64_t __udivdi3(uint64_t dividend, uint64_t divisor) +{ + uint32_t d = divisor; + + /* Scale divisor to 32 bits */ + if (divisor > 0xffffffffULL) { + unsigned int shift = fls(divisor >> 32); + + d = divisor >> shift; + dividend >>= shift; + } + + /* avoid 64 bit division if possible */ + if (dividend >> 32) + do_div(dividend, d); + else + dividend = (uint32_t) dividend / d; + + return dividend; +} +EXPORT_SYMBOL(__udivdi3); - 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/