From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964952AbbLROUA (ORCPT ); Fri, 18 Dec 2015 09:20:00 -0500 Received: from mail-wm0-f44.google.com ([74.125.82.44]:38737 "EHLO mail-wm0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753869AbbLROT4 (ORCPT ); Fri, 18 Dec 2015 09:19:56 -0500 From: Daniel Lezcano To: tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, mingo@kernel.org, Jisheng Zhang , Srinivas Kandagatla , Maxime Coquelin , Patrice Chotard , kernel@stlinux.com (open list:ARM/STI ARCHITECTURE) Subject: [PATCH 61/69] clockevents/drivers/arm_global_timer: Use writel_relaxed in gt_compare_set Date: Fri, 18 Dec 2015 15:18:14 +0100 Message-Id: <1450448302-27429-61-git-send-email-daniel.lezcano@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1450448302-27429-1-git-send-email-daniel.lezcano@linaro.org> References: <5672CB9E.7090707@linaro.org> <1450448302-27429-1-git-send-email-daniel.lezcano@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jisheng Zhang Use the relaxed version to improve performance. we measured time of 4096 rounds of gt_compare_set() spent on Marvell BG2Q: before the patch: 3690648ns on average after the patch: 1083023ns on average improved by 70%! Signed-off-by: Jisheng Zhang Signed-off-by: Daniel Lezcano --- drivers/clocksource/arm_global_timer.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c index a2cb6fa..f99be6b 100644 --- a/drivers/clocksource/arm_global_timer.c +++ b/drivers/clocksource/arm_global_timer.c @@ -99,17 +99,17 @@ static void gt_compare_set(unsigned long delta, int periodic) counter += delta; ctrl = GT_CONTROL_TIMER_ENABLE; - writel(ctrl, gt_base + GT_CONTROL); - writel(lower_32_bits(counter), gt_base + GT_COMP0); - writel(upper_32_bits(counter), gt_base + GT_COMP1); + writel_relaxed(ctrl, gt_base + GT_CONTROL); + writel_relaxed(lower_32_bits(counter), gt_base + GT_COMP0); + writel_relaxed(upper_32_bits(counter), gt_base + GT_COMP1); if (periodic) { - writel(delta, gt_base + GT_AUTO_INC); + writel_relaxed(delta, gt_base + GT_AUTO_INC); ctrl |= GT_CONTROL_AUTO_INC; } ctrl |= GT_CONTROL_COMP_ENABLE | GT_CONTROL_IRQ_ENABLE; - writel(ctrl, gt_base + GT_CONTROL); + writel_relaxed(ctrl, gt_base + GT_CONTROL); } static int gt_clockevent_shutdown(struct clock_event_device *evt) -- 1.9.1