From patchwork Tue Dec 10 00:34:45 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Soren Brinkmann X-Patchwork-Id: 3313791 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 6440B9F37A for ; Tue, 10 Dec 2013 00:36:37 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 765AB2017B for ; Tue, 10 Dec 2013 00:36:36 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5106020108 for ; Tue, 10 Dec 2013 00:36:35 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VqBIx-00060w-CL; Tue, 10 Dec 2013 00:36:03 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VqBIr-0008Eq-Qv; Tue, 10 Dec 2013 00:35:57 +0000 Received: from mail-pd0-x233.google.com ([2607:f8b0:400e:c02::233]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VqBIg-0008B6-9O for linux-arm-kernel@lists.infradead.org; Tue, 10 Dec 2013 00:35:48 +0000 Received: by mail-pd0-f179.google.com with SMTP id r10so6201955pdi.38 for ; Mon, 09 Dec 2013 16:35:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=ozxkjxMLJA90AG2i2s70EvK/phvHOc8k51CJ7s7bYhE=; b=L+5r4KQKJeOT7zeMwvNpuQPO7MNGKW3mEDLlFcM7ghP13VkNU99AV6xeBm4XDHqM8K 6Gh/+FHCA1eLS9nOVmp+yJI6Nm3QmLkMasB0I2aZVRkwwaelgCDpnNZojsgd/Bd6QocM ovmmsq8k1osfkb0ML1bO8InlHLor/fZ8oPdLafar805U4c3ZKN0TSqtE7XZ8BnRlTy0Q HI/Ub84aRuEl1ypks0m2UXOvCle8COHTGlFkneyrfLOiG2YNrNUXx+GWtzTXw+xoVS4O 8AobNxx0A2dxfUodHgvoFQfBpC3HV6wK2pv1BUEClaHfXGuBVAOQzIaq8cnWlrPMVH9K JfHA== X-Received: by 10.66.242.17 with SMTP id wm17mr24502899pac.102.1386635723971; Mon, 09 Dec 2013 16:35:23 -0800 (PST) Received: from localhost ([149.199.62.254]) by mx.google.com with ESMTPSA id xv2sm20969598pbb.39.2013.12.09.16.35.22 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Mon, 09 Dec 2013 16:35:23 -0800 (PST) From: Soren Brinkmann To: Daniel Lezcano , Thomas Gleixner Subject: [PATCH 1/2] time: Serialize calls to 'clockevents_update_freq' in the timing core Date: Mon, 9 Dec 2013 16:34:45 -0800 Message-Id: <1386635686-15686-2-git-send-email-soren.brinkmann@xilinx.com> X-Mailer: git-send-email 1.8.5.1 In-Reply-To: <1386635686-15686-1-git-send-email-soren.brinkmann@xilinx.com> References: <1386635686-15686-1-git-send-email-soren.brinkmann@xilinx.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131209_193546_594425_0020E332 X-CRM114-Status: GOOD ( 17.90 ) X-Spam-Score: -1.9 (-) Cc: Mark Rutland , devicetree@vger.kernel.org, Russell King , Pawel Moll , Ian Campbell , Stephen Warren , Michal Simek , Rob Herring , linux-kernel@vger.kernel.org, =?UTF-8?q?S=C3=B6ren=20Brinkmann?= , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Thomas Gleixner We can identify the broadcast device in the core and serialize all callers including interrupts on a different CPU against the update. Also, disabling interrupts is moved into the core allowing callers to leave interrutps enabled when calling clockevents_update_freq(). Cc: Thomas Gleixner Signed-off-by: Soren Brinkmann --- kernel/time/clockevents.c | 29 ++++++++++++++++++++++------- kernel/time/tick-broadcast.c | 25 +++++++++++++++++++------ kernel/time/tick-internal.h | 4 ++++ 3 files changed, 45 insertions(+), 13 deletions(-) diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 086ad6043bcb..641d91003a45 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -439,6 +439,16 @@ void clockevents_config_and_register(struct clock_event_device *dev, } EXPORT_SYMBOL_GPL(clockevents_config_and_register); +int __clockevents_update_freq(struct clock_event_device *dev, u32 freq) +{ + clockevents_config(dev, freq); + + if (dev->mode != CLOCK_EVT_MODE_ONESHOT) + return 0; + + return clockevents_program_event(dev, dev->next_event, false); +} + /** * clockevents_update_freq - Update frequency and reprogram a clock event device. * @dev: device to modify @@ -446,17 +456,22 @@ EXPORT_SYMBOL_GPL(clockevents_config_and_register); * * Reconfigure and reprogram a clock event device in oneshot * mode. Must be called on the cpu for which the device delivers per - * cpu timer events with interrupts disabled! Returns 0 on success, - * -ETIME when the event is in the past. + * cpu timer events. If called for the broadcast device the core takes + * care of serialization. + * + * Returns 0 on success, -ETIME when the event is in the past. */ int clockevents_update_freq(struct clock_event_device *dev, u32 freq) { - clockevents_config(dev, freq); - - if (dev->mode != CLOCK_EVT_MODE_ONESHOT) - return 0; + unsigned long flags; + int ret; - return clockevents_program_event(dev, dev->next_event, false); + local_irq_save(flags); + ret = tick_broadcast_update_freq(dev, freq); + if (ret == -ENODEV) + ret = __clockevents_update_freq(dev, freq); + local_irq_restore(flags); + return ret; } /* diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 9532690daaa9..63a33b33fc4e 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -120,6 +120,19 @@ int tick_is_broadcast_device(struct clock_event_device *dev) return (dev && tick_broadcast_device.evtdev == dev); } +int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq) +{ + int ret = -ENODEV; + + if (tick_is_broadcast_device(dev)) { + raw_spin_lock(&tick_broadcast_lock); + ret = __clockevents_update_freq(dev, freq); + raw_spin_unlock(&tick_broadcast_lock); + } + return ret; +} + + static void err_broadcast(const struct cpumask *mask) { pr_crit_once("Failed to broadcast timer tick. Some CPUs may be unresponsive.\n"); @@ -272,12 +285,8 @@ static void tick_do_broadcast(struct cpumask *mask) */ static void tick_do_periodic_broadcast(void) { - raw_spin_lock(&tick_broadcast_lock); - cpumask_and(tmpmask, cpu_online_mask, tick_broadcast_mask); tick_do_broadcast(tmpmask); - - raw_spin_unlock(&tick_broadcast_lock); } /* @@ -287,13 +296,15 @@ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) { ktime_t next; + raw_spin_lock(&tick_broadcast_lock); + tick_do_periodic_broadcast(); /* * The device is in periodic mode. No reprogramming necessary: */ if (dev->mode == CLOCK_EVT_MODE_PERIODIC) - return; + goto unlock; /* * Setup the next period for devices, which do not have @@ -306,9 +317,11 @@ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) next = ktime_add(next, tick_period); if (!clockevents_program_event(dev, next, false)) - return; + goto unlock; tick_do_periodic_broadcast(); } +unlock: + raw_spin_unlock(&tick_broadcast_lock); } /* diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index 18e71f7fbc2a..22fd431a02eb 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -111,6 +111,7 @@ extern int tick_resume_broadcast(void); extern void tick_broadcast_init(void); extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast); +int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq); #else /* !BROADCAST */ @@ -133,6 +134,8 @@ static inline void tick_shutdown_broadcast(unsigned int *cpup) { } static inline void tick_suspend_broadcast(void) { } static inline int tick_resume_broadcast(void) { return 0; } static inline void tick_broadcast_init(void) { } +static inline int tick_broadcast_update_freq(struct clock_event_device *dev, + u32 freq) { return -ENODEV; } /* * Set the periodic handler in non broadcast mode @@ -154,4 +157,5 @@ static inline int tick_device_is_functional(struct clock_event_device *dev) #endif +int __clockevents_update_freq(struct clock_event_device *dev, u32 freq); extern void do_timer(unsigned long ticks);