From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754776Ab2LRMIU (ORCPT ); Tue, 18 Dec 2012 07:08:20 -0500 Received: from service87.mimecast.com ([91.220.42.44]:44751 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754352Ab2LRMIT (ORCPT ); Tue, 18 Dec 2012 07:08:19 -0500 From: Mark Rutland To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux@arm.linux.org.uk, tglx@linutronix.de, nico@linaro.org, will.deacon@arm.com, marc.zyngier@arm.com, john.stultz@linaro.org, Mark Rutland 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 Content-Type: text/plain; charset=WINDOWS-1252 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id qBIC8Nrf018317 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; -- 1.7.0.4