From patchwork Mon Oct 29 14:24:18 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linus Walleij X-Patchwork-Id: 1663721 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id 02E163FDDA for ; Mon, 29 Oct 2012 14:26:48 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TSqGX-0001oE-Rj; Mon, 29 Oct 2012 14:24:33 +0000 Received: from mail.df.lth.se ([194.47.250.12]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1TSqGU-0001nv-JU for linux-arm-kernel@lists.infradead.org; Mon, 29 Oct 2012 14:24:31 +0000 Received: from mer.df.lth.se (mer.df.lth.se [194.47.250.37]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.df.lth.se (Postfix) with ESMTPS id C47C265D87; Mon, 29 Oct 2012 15:24:25 +0100 (CET) Received: from mer.df.lth.se (triad@localhost.localdomain [127.0.0.1]) by mer.df.lth.se (8.14.3/8.14.3/Debian-9.4) with ESMTP id q9TEOPnv023056; Mon, 29 Oct 2012 15:24:25 +0100 Received: (from triad@localhost) by mer.df.lth.se (8.14.3/8.14.3/Submit) id q9TEON14023055; Mon, 29 Oct 2012 15:24:23 +0100 From: Linus Walleij To: linux-arm-kernel@lists.infradead.org, Catalin Marinas Subject: [PATCH] clocksource: arm_generic: use integer math helpers Date: Mon, 29 Oct 2012 15:24:18 +0100 Message-Id: <1351520658-23028-1-git-send-email-linus.walleij@linaro.org> X-Mailer: git-send-email 1.7.2.5 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -3.3 (---) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-3.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [194.47.250.12 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.7 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Marc Zyngier , John Stultz , Thomas Gleixner , Linus Walleij , Catalin Marinas X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org This will make the two crucial integer divisions in the generic ARM arch timer used for ARMv8 use the kernel DIV_ROUND_CLOSEST() helper inline from so they get more precise. Cc: Marc Zyngier Cc: Catalin Marinas Signed-off-by: Linus Walleij Acked-by: Catalin Marinas --- drivers/clocksource/arm_generic.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/clocksource/arm_generic.c b/drivers/clocksource/arm_generic.c index c4d9f95..6cd1b30 100644 --- a/drivers/clocksource/arm_generic.c +++ b/drivers/clocksource/arm_generic.c @@ -127,7 +127,7 @@ static void __init arch_timer_calibrate(void) /* Cache the sched_clock multiplier to save a divide in the hot path. */ - sched_clock_mult = NSEC_PER_SEC / arch_timer_rate; + sched_clock_mult = DIV_ROUND_CLOSEST(NSEC_PER_SEC, arch_timer_rate); pr_info("Architected local timer running at %u.%02uMHz.\n", arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100); @@ -221,7 +221,7 @@ int __init arm_generic_timer_init(void) clocksource_register_hz(&clocksource_counter, arch_timer_rate); /* Calibrate the delay loop directly */ - lpj_fine = arch_timer_rate / HZ; + lpj_fine = DIV_ROUND_CLOSEST(arch_timer_rate, HZ); /* Immediately configure the timer on the boot CPU */ arch_timer_setup(per_cpu_ptr(&arch_timer_evt, smp_processor_id()));