From patchwork Mon Feb 3 22:34:31 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Soren Brinkmann X-Patchwork-Id: 3572201 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 118799F38A for ; Mon, 3 Feb 2014 22:36:44 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 252202015E for ; Mon, 3 Feb 2014 22:36:43 +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 1FDF120158 for ; Mon, 3 Feb 2014 22:36:42 +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 1WAS7G-000813-6O; Mon, 03 Feb 2014 22:35:46 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WAS73-0004ri-7y; Mon, 03 Feb 2014 22:35:33 +0000 Received: from mail-qa0-x232.google.com ([2607:f8b0:400d:c00::232]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WAS6h-0004mo-Dh for linux-arm-kernel@lists.infradead.org; Mon, 03 Feb 2014 22:35:13 +0000 Received: by mail-qa0-f50.google.com with SMTP id cm18so11238701qab.9 for ; Mon, 03 Feb 2014 14:34:49 -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=MhyUtMmEDPwQrpRy0tdTXiQnlXaG26If4bRKnL+6Wg0=; b=D4oYuZgLCU9joXISPTBpU4M2HjxP0/V5X86MMvZ5+FafxeCTZe+K2RBZLdnTM5RraO W6zQ44AsrR9teNUbeRse+Z6x3LEPL0FWg4wdusJM8TW+RvvMYFaixqwFFhcrdOJENVbu ONewTdfNygk5ODh84W4y9ESDlhtH1oWGIbCHMuYvLFLXzwFCJdR41/D0VkQHUU4DyAMB O/l+gbXbnL0RvW3rTnrSU3owu22HjF2dfjF1qoJChDKexV6759G9llrX1pADePw6Jehy INWWHUJLQ4Q8tVZk3oqahycayPVCJ3W2B5XavV+91fuqy7stl8Lrj/GRY0A01cR7OlGJ JW+w== X-Received: by 10.140.97.137 with SMTP id m9mr56570002qge.95.1391466889373; Mon, 03 Feb 2014 14:34:49 -0800 (PST) Received: from localhost ([149.199.62.254]) by mx.google.com with ESMTPSA id k1sm60711584qat.16.2014.02.03.14.34.48 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Mon, 03 Feb 2014 14:34:48 -0800 (PST) From: Soren Brinkmann To: Thomas Gleixner , Daniel Lezcano , Michal Simek Subject: [PATCH v3 1/7] time: Serialize calls to 'clockevents_update_freq' in the timing core Date: Mon, 3 Feb 2014 14:34:31 -0800 Message-Id: <1391466877-28908-2-git-send-email-soren.brinkmann@xilinx.com> X-Mailer: git-send-email 1.8.5.3 In-Reply-To: <1391466877-28908-1-git-send-email-soren.brinkmann@xilinx.com> References: <1391466877-28908-1-git-send-email-soren.brinkmann@xilinx.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140203_173511_741162_ADE56F1D X-CRM114-Status: GOOD ( 17.63 ) X-Spam-Score: -1.9 (-) Cc: =?UTF-8?q?S=C3=B6ren=20Brinkmann?= , linux-kernel@vger.kernel.org, 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=-4.6 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 43780ab5e279..003e6c3663b1 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 8329669b51ec..26f1c0ba9d81 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 @@ -154,5 +157,6 @@ 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); extern void update_wall_time(void);