Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965873AbaKNPby (ORCPT ); Fri, 14 Nov 2014 10:31:54 -0500 Received: from service87.mimecast.com ([91.220.42.44]:44986 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965567AbaKNPbv convert rfc822-to-8bit (ORCPT ); Fri, 14 Nov 2014 10:31:51 -0500 Message-ID: <54662062.8030807@arm.com> Date: Fri, 14 Nov 2014 15:31:46 +0000 From: Marc Zyngier User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130330 Thunderbird/17.0.5 MIME-Version: 1.0 To: Thomas Gleixner CC: LKML , Jiang Liu , Bjorn Helgaas , "grant.likely@linaro.org" , Yingjoe Chen , Yijing Wang Subject: Re: [patch 07/16] genirq: Introduce helper irq_domain_set_info() to reduce duplicated code References: <20141112133941.647950773@linutronix.de> <20141112134120.393705922@linutronix.de> In-Reply-To: <20141112134120.393705922@linutronix.de> X-Enigmail-Version: 1.4.6 X-OriginalArrivalTime: 14 Nov 2014 15:31:47.0113 (UTC) FILETIME=[1A21F190:01D00020] X-MC-Unique: 114111415314908801 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/11/14 13:43, Thomas Gleixner wrote: > From: Jiang Liu > > Signed-off-by: Jiang Liu > Cc: Bjorn Helgaas > Cc: Grant Likely > Cc: Marc Zyngier > Cc: Yingjoe Chen > Cc: Yijing Wang > Signed-off-by: Thomas Gleixner > --- > include/linux/irqdomain.h | 5 +++++ > kernel/irq/irqdomain.c | 10 ++++++++++ > 2 files changed, 15 insertions(+) > > Index: tip/include/linux/irqdomain.h > =================================================================== > --- tip.orig/include/linux/irqdomain.h > +++ tip/include/linux/irqdomain.h > @@ -33,6 +33,7 @@ > #define _LINUX_IRQDOMAIN_H > > #include > +#include > #include > > struct device_node; > @@ -263,6 +264,10 @@ extern int irq_domain_set_hwirq_and_chip > irq_hw_number_t hwirq, > struct irq_chip *chip, > void *chip_data); > +extern void irq_domain_set_info(struct irq_domain *domain, unsigned int virq, > + irq_hw_number_t hwirq, struct irq_chip *chip, > + void *chip_data, irq_flow_handler_t handler, > + void *handler_data, const char *handler_name); > extern void irq_domain_reset_irq_data(struct irq_data *irq_data); > extern void irq_domain_free_irqs_common(struct irq_domain *domain, > int virq, int nr_irqs); > Index: tip/kernel/irq/irqdomain.c > =================================================================== > --- tip.orig/kernel/irq/irqdomain.c > +++ tip/kernel/irq/irqdomain.c > @@ -882,6 +882,16 @@ int irq_domain_set_hwirq_and_chip(struct > return 0; > } > > +void irq_domain_set_info(struct irq_domain *domain, unsigned int virq, > + irq_hw_number_t hwirq, struct irq_chip *chip, > + void *chip_data, irq_flow_handler_t handler, > + void *handler_data, const char *handler_name) > +{ > + irq_domain_set_hwirq_and_chip(domain, virq, hwirq, chip, chip_data); > + __irq_set_handler(virq, handler, 0, handler_name); > + irq_set_handler_data(virq, handler_data); > +} > + We still have the issue that, depending on where in the stack this is called, this will succeed or fail: If this is called from the inner irqchip, __irq_set_handler() will fail, as it will look at the outer domain as the (desc->irq_data.chip == &no_irq_chip) test fails (we haven't set the top level yet). I have this very imperfect workaround in my tree: diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index d028b34..91e6515 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -731,7 +731,16 @@ __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained, if (!handle) { handle = handle_bad_irq; } else { - if (WARN_ON(desc->irq_data.chip == &no_irq_chip)) +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY + struct irq_data *irq_data = &desc->irq_data; + while (irq_data) { + if (irq_data->chip != &no_irq_chip) + break; + irq_data = irq_data->parent_data; + } +#endif + + if (WARN_ON(!irq_data || irq_data->chip == &no_irq_chip)) goto out; } Which translate into: If there is at least one irqchip in the domain, it will probably sort itself out. Not ideal. Any real solution to this problem? GICv2 faces this exact problem, as some of its interrupts are used directly, and some others are used through the MSI domain. In the GIC driver, it is almost impossible to find out... Thanks, M. -- Jazz is not dead. It just smells funny... -- 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/