From patchwork Tue Dec 18 12:06:57 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 1891441 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 C2D693FC64 for ; Tue, 18 Dec 2012 12:11:18 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TkvyL-0000Em-WE; Tue, 18 Dec 2012 12:08:34 +0000 Received: from service87.mimecast.com ([91.220.42.44]) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1Tkvy8-000091-7e for linux-arm-kernel@lists.infradead.org; Tue, 18 Dec 2012 12:08:21 +0000 Received: from cam-owa1.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.21]) by service87.mimecast.com; Tue, 18 Dec 2012 12:08:11 +0000 Received: from localhost.localdomain ([10.1.255.212]) by cam-owa1.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.0); Tue, 18 Dec 2012 12:08:09 +0000 From: Mark Rutland To: linux-kernel@vger.kernel.org Subject: [RFC PATCH 4/5] clockevents: Add generic timer broadcast function Date: Tue, 18 Dec 2012 12:06:57 +0000 Message-Id: <1355832418-31692-5-git-send-email-mark.rutland@arm.com> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1355832418-31692-1-git-send-email-mark.rutland@arm.com> References: <1355832418-31692-1-git-send-email-mark.rutland@arm.com> X-OriginalArrivalTime: 18 Dec 2012 12:08:09.0062 (UTC) FILETIME=[58195060:01CDDD18] X-MC-Unique: 112121812081102901 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20121218_070820_668667_E3FC7E17 X-CRM114-Status: GOOD ( 11.80 ) X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [91.220.42.44 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Mark Rutland , linux@arm.linux.org.uk, nico@linaro.org, marc.zyngier@arm.com, will.deacon@arm.com, john.stultz@linaro.org, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org 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 Currently, the timer broadcast mechanism is defined by a function pointer on struct clock_event_device. As the fundamental mechanism for broadcast is architecture-specific, this means that clock_event_device drivers cannot be shared across multiple architectures. This patch adds an (optional) architecture-specific function for timer tick broadcast, allowing drivers which may require broadcast functionality to be shared across multiple architectures. Signed-off-by: Mark Rutland --- include/linux/clockchips.h | 5 +++++ kernel/time/Kconfig | 4 ++++ kernel/time/tick-broadcast.c | 15 +++++++++++++++ 3 files changed, 24 insertions(+), 0 deletions(-) diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index e1089aa..6634652 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -162,6 +162,11 @@ extern void clockevents_suspend(void); extern void clockevents_resume(void); #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST +#ifdef CONFIG_ARCH_HAS_TICK_BROADCAST +extern void tick_broadcast(const struct cpumask *mask); +#else +#define tick_broadcast NULL +#endif extern int tick_receive_broadcast(void); #endif diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index 8601f0d..b696922 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -38,6 +38,10 @@ config GENERIC_CLOCKEVENTS_BUILD default y depends on GENERIC_CLOCKEVENTS +# Architecture can handle broadcast in a driver-agnostic way +config ARCH_HAS_TICK_BROADCAST + bool + # Clockevents broadcasting infrastructure config GENERIC_CLOCKEVENTS_BROADCAST bool diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index c2dd022..ec22a80 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "tick-internal.h" @@ -86,6 +87,12 @@ int tick_is_broadcast_device(struct clock_event_device *dev) return (dev && tick_broadcast_device.evtdev == dev); } +static void err_broadcast(const struct cpumask *mask) +{ + pr_crit_once("Attempted to broadcast tick, but no broadcast mechanism " + "present. Some CPUs may be unresponsive."); +} + /* * Check, if the device is disfunctional and a place holder, which * needs to be handled by the broadcast device. @@ -105,6 +112,14 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) */ if (!tick_device_is_functional(dev)) { dev->event_handler = tick_handle_periodic; + if (!dev->broadcast) + dev->broadcast = tick_broadcast; + if (!dev->broadcast) { + pr_warn_once("%s depends on broadcast, but no " + "broadcast function available\n", + dev->name); + dev->broadcast = err_broadcast; + } cpumask_set_cpu(cpu, tick_get_broadcast_mask()); tick_broadcast_start_periodic(tick_broadcast_device.evtdev); ret = 1;