Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932084AbaKXSUY (ORCPT ); Mon, 24 Nov 2014 13:20:24 -0500 Received: from www.linutronix.de ([62.245.132.108]:40517 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754345AbaKXSUK (ORCPT ); Mon, 24 Nov 2014 13:20:10 -0500 Date: Mon, 24 Nov 2014 19:20:07 +0100 (CET) From: Thomas Gleixner To: Daniel Thompson cc: Jason Cooper , Russell King , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, patches@linaro.org, linaro-kernel@lists.linaro.org, John Stultz , Sumit Semwal , Dirk Behme , Daniel Drake , Dmitry Pervushin , Marc Zyngier Subject: Re: [PATCH 3.18-rc3 v8 1/4] irqchip: gic: Make gic_raise_softirq() FIQ-safe In-Reply-To: <1415968543-29469-2-git-send-email-daniel.thompson@linaro.org> Message-ID: References: <1415183260-6389-1-git-send-email-daniel.thompson@linaro.org> <1415968543-29469-1-git-send-email-daniel.thompson@linaro.org> <1415968543-29469-2-git-send-email-daniel.thompson@linaro.org> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 14 Nov 2014, Daniel Thompson wrote: > diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c > index 38493ff28fa5..0db62a6f1ee3 100644 > --- a/drivers/irqchip/irq-gic.c > +++ b/drivers/irqchip/irq-gic.c > @@ -73,6 +73,13 @@ struct gic_chip_data { > static DEFINE_RAW_SPINLOCK(irq_controller_lock); > > /* > + * This lock may be locked for reading by FIQ handlers. Thus although > + * read locking may be used liberally, write locking must only take > + * place only when local FIQ handling is disabled. > + */ > +static DEFINE_RWLOCK(fiq_safe_cpu_map_lock); > + > +/* > * The GIC mapping of CPU interfaces does not necessarily match > * the logical CPU numbering. Let's use a mapping as returned > * by the GIC itself. > @@ -624,7 +631,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) > int cpu; > unsigned long flags, map = 0; > > - raw_spin_lock_irqsave(&irq_controller_lock, flags); > + read_lock_irqsave(&fiq_safe_cpu_map_lock, flags); Just for the record: You might have noticed that you replace a raw lock with a non raw one. That's not an issue on mainline, but that pretty much renders that code broken for RT. Surely nothing I worry too much about given the current state of RT. Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/