From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754148Ab1JJNGd (ORCPT ); Mon, 10 Oct 2011 09:06:33 -0400 Received: from smtp.ctxuk.citrix.com ([62.200.22.115]:11787 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754082Ab1JJNGc (ORCPT ); Mon, 10 Oct 2011 09:06:32 -0400 X-IronPort-AV: E=Sophos;i="4.68,517,1312156800"; d="scan'208";a="8302885" 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: Mon, 10 Oct 2011 14:06:30 +0100 In-Reply-To: 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> Organization: Citrix Systems, Inc. Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.0.3- Content-Transfer-Encoding: 7bit Message-ID: <1318251990.21903.433.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 On Fri, 2011-10-07 at 17:29 +0100, Thomas Gleixner wrote: > On Fri, 7 Oct 2011, Ian Campbell wrote: > > On Mon, 2011-10-03 at 22:35 +0200, Thomas Gleixner wrote: > > /** > > + * irq_pm_syscore_ops - enable interrupt lines early > > + * > > + * Enable all interrupt lines with %IRQF_EARLY_RESUME set > > + */ > > +static void irq_pm_syscore_resume(void) > > +{ > > + struct irq_desc *desc; > > + int irq; > > + > > + for_each_irq_desc(irq, desc) { > > + unsigned long flags; > > + > > + if (!desc->action || !(desc->action->flags & IRQF_EARLY_RESUME)) > > + continue; > > + > > + raw_spin_lock_irqsave(&desc->lock, flags); > > + __enable_irq(desc, irq, true); > > + raw_spin_unlock_irqrestore(&desc->lock, flags); > > + } > > +} > > Come on, this is a full copy of resume_device_irqs(). What about > having a common function with an (bool early) argument and call it > from both syscore and resume_device? Yes, that's a good idea. >>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); /** -- 1.7.2.5