From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932867Ab1JNNYA (ORCPT ); Fri, 14 Oct 2011 09:24:00 -0400 Received: from smtp.eu.citrix.com ([62.200.22.115]:41327 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932744Ab1JNNX7 (ORCPT ); Fri, 14 Oct 2011 09:23:59 -0400 X-IronPort-AV: E=Sophos;i="4.69,346,1315180800"; d="scan'208";a="8397181" Subject: Re: xen: IPI interrupts not resumed early enough on suspend/resume From: Ian Campbell To: Thomas Gleixner CC: Jeremy Fitzhardinge , "Konrad Rzeszutek Wilk" , xen-devel , linux-kernel , "Rafael J. Wysocki" Date: Fri, 14 Oct 2011 14:23:57 +0100 In-Reply-To: <1318251990.21903.433.camel@zakaz.uk.xensource.com> References: <1317654626.21903.72.camel@zakaz.uk.xensource.com> <1317668908.11991.20.camel@dagon.hellion.org.uk> <1318001583.21903.355.camel@zakaz.uk.xensource.com> <1318251990.21903.433.camel@zakaz.uk.xensource.com> Organization: Citrix Systems, Inc. Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.0.3- Content-Transfer-Encoding: 7bit Message-ID: <1318598637.21903.889.camel@zakaz.uk.xensource.com> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ping? The original issue has made it into longterm-2.6.32.y and then onto Debian (bug #644604) so people keep asking me about it... Ian. On Mon, 2011-10-10 at 14:06 +0100, Ian Campbell wrote: > From dc8a8329f3e97f30e1290c898c816250aa7e8957 Mon Sep 17 00:00:00 2001 > From: Ian Campbell > Date: Mon, 3 Oct 2011 15:37:00 +0100 > Subject: [PATCH] irq: add IRQF_RESUME_EARLY and resume such IRQs earlier in the process > > This adds a mechanism to resume selected IRQs during syscore_resume instead of > dpm_resume_noirq. > > Under Xen we need to resume IRQs associated with IPIs early enough that the > resched IPI is unmasked and we can therefore schedule ourselves out of the > stop_machine where the suspend/resume takes place. > > This issue was introduced by 676dc3cf5bc3 "xen: Use IRQF_FORCE_RESUME". > > Signed-off-by: Ian Campbell > Cc: Thomas Gleixner > Cc: Rafael J. Wysocki > Cc: Jeremy Fitzhardinge > Cc: Konrad Rzeszutek Wilk > Cc: xen-devel > Cc: stable@kernel.org (at least to 2.6.32.y) > --- > drivers/xen/events.c | 2 +- > include/linux/interrupt.h | 3 ++ > kernel/irq/pm.c | 48 ++++++++++++++++++++++++++++++++++++++------ > 3 files changed, 45 insertions(+), 8 deletions(-) > > diff --git a/drivers/xen/events.c b/drivers/xen/events.c > index 7523719..44490de 100644 > --- a/drivers/xen/events.c > +++ b/drivers/xen/events.c > @@ -1021,7 +1021,7 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi, > if (irq < 0) > return irq; > > - irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME; > + irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME; > retval = request_irq(irq, handler, irqflags, devname, dev_id); > if (retval != 0) { > unbind_from_irq(irq); > diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h > index a103732..f51a81b 100644 > --- a/include/linux/interrupt.h > +++ b/include/linux/interrupt.h > @@ -59,6 +59,8 @@ > * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend > * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set > * IRQF_NO_THREAD - Interrupt cannot be threaded > + * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device > + * resume time. > */ > #define IRQF_DISABLED 0x00000020 > #define IRQF_SAMPLE_RANDOM 0x00000040 > @@ -72,6 +74,7 @@ > #define IRQF_NO_SUSPEND 0x00004000 > #define IRQF_FORCE_RESUME 0x00008000 > #define IRQF_NO_THREAD 0x00010000 > +#define IRQF_EARLY_RESUME 0x00020000 > > #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD) > > diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c > index f76fc00..86bcd79 100644 > --- a/kernel/irq/pm.c > +++ b/kernel/irq/pm.c > @@ -9,6 +9,7 @@ > #include > #include > #include > +#include > > #include "internals.h" > > @@ -39,25 +40,58 @@ void suspend_device_irqs(void) > } > EXPORT_SYMBOL_GPL(suspend_device_irqs); > > -/** > - * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs() > - * > - * Enable all interrupt lines previously disabled by suspend_device_irqs() that > - * have the IRQS_SUSPENDED flag set. > - */ > -void resume_device_irqs(void) > +static resume_irqs(bool want_early) > { > struct irq_desc *desc; > int irq; > > for_each_irq_desc(irq, desc) { > unsigned long flags; > + bool is_early = desc->action && > + desc->action->flags & IRQF_EARLY_RESUME; > + > + if (is_early != want_early) > + continue; > > raw_spin_lock_irqsave(&desc->lock, flags); > __enable_irq(desc, irq, true); > raw_spin_unlock_irqrestore(&desc->lock, flags); > } > } > + > +/** > + * irq_pm_syscore_ops - enable interrupt lines early > + * > + * Enable all interrupt lines with %IRQF_EARLY_RESUME set. > + */ > +static void irq_pm_syscore_resume(void) > +{ > + resume_irqs(true); > +} > + > +static struct syscore_ops irq_pm_syscore_ops = { > + .resume = irq_pm_syscore_resume, > +}; > + > +static int __init irq_pm_init_ops(void) > +{ > + register_syscore_ops(&irq_pm_syscore_ops); > + return 0; > +} > + > +device_initcall(irq_pm_init_ops); > + > +/** > + * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs() > + * > + * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously > + * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag > + * set as well as those with %IRQF_FORCE_RESUME. > + */ > +void resume_device_irqs(void) > +{ > + resume_irqs(false); > +} > EXPORT_SYMBOL_GPL(resume_device_irqs); > > /**