From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752745AbdFNMmY (ORCPT ); Wed, 14 Jun 2017 08:42:24 -0400 Received: from mail-wr0-f178.google.com ([209.85.128.178]:35709 "EHLO mail-wr0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752667AbdFNMmS (ORCPT ); Wed, 14 Jun 2017 08:42:18 -0400 From: Daniel Lezcano To: tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, Linus Walleij , Andrew Jeffery , Joel Stanley , Jonas Jensen Subject: [PATCH 19/23] clocksource/drivers/fttmr010: Optimize sched_clock() Date: Wed, 14 Jun 2017 14:39:40 +0200 Message-Id: <1497443984-12371-19-git-send-email-daniel.lezcano@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1497443984-12371-1-git-send-email-daniel.lezcano@linaro.org> References: <20170614123800.GH2261@mai> <1497443984-12371-1-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: Linus Walleij The sched_clock() call should be really fast so we want to avoid an extra if() clause on the read path if possible. Implement two sched_clock_read() functions, one if the timer counts up and one if it counts down. Incidentally this also mirrors how clocksource_mmio_init() works and make things simple and easy to understand. Suggested-by: Daniel Lezcano Cc: Andrew Jeffery Cc: Joel Stanley Cc: Jonas Jensen Signed-off-by: Linus Walleij Signed-off-by: Daniel Lezcano --- drivers/clocksource/timer-fttmr010.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/clocksource/timer-fttmr010.c b/drivers/clocksource/timer-fttmr010.c index a21020c..b56d7bd 100644 --- a/drivers/clocksource/timer-fttmr010.c +++ b/drivers/clocksource/timer-fttmr010.c @@ -91,13 +91,16 @@ static inline struct fttmr010 *to_fttmr010(struct clock_event_device *evt) return container_of(evt, struct fttmr010, clkevt); } -static u64 notrace fttmr010_read_sched_clock(void) +static u64 notrace fttmr010_read_sched_clock_up(void) { - if (local_fttmr->count_down) - return ~readl(local_fttmr->base + TIMER2_COUNT); return readl(local_fttmr->base + TIMER2_COUNT); } +static u64 notrace fttmr010_read_sched_clock_down(void) +{ + return ~readl(local_fttmr->base + TIMER2_COUNT); +} + static int fttmr010_timer_set_next_event(unsigned long cycles, struct clock_event_device *evt) { @@ -302,15 +305,17 @@ static int __init fttmr010_common_init(struct device_node *np, bool is_aspeed) "FTTMR010-TIMER2", fttmr010->tick_rate, 300, 32, clocksource_mmio_readl_down); + sched_clock_register(fttmr010_read_sched_clock_down, 32, + fttmr010->tick_rate); } else { writel(0, fttmr010->base + TIMER2_LOAD); clocksource_mmio_init(fttmr010->base + TIMER2_COUNT, "FTTMR010-TIMER2", fttmr010->tick_rate, 300, 32, clocksource_mmio_readl_up); + sched_clock_register(fttmr010_read_sched_clock_up, 32, + fttmr010->tick_rate); } - sched_clock_register(fttmr010_read_sched_clock, 32, - fttmr010->tick_rate); /* * Setup clockevent timer (interrupt-driven) on timer 1. -- 2.7.4