From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756459AbYA2LVE (ORCPT ); Tue, 29 Jan 2008 06:21:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752426AbYA2LUy (ORCPT ); Tue, 29 Jan 2008 06:20:54 -0500 Received: from ftp.linux-mips.org ([194.74.144.162]:37591 "EHLO ftp.linux-mips.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750835AbYA2LUw (ORCPT ); Tue, 29 Jan 2008 06:20:52 -0500 Date: Tue, 29 Jan 2008 11:20:48 +0000 From: Ralf Baechle To: Rob Landley Cc: linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org Subject: [PATCH 1/2] IRQ_NOPROBE helper functions Message-ID: <20080129112048.GA8665@linux-mips.org> References: <200801280217.38273.rob@landley.net> <20080129111622.GC7237@linux-mips.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080129111622.GC7237@linux-mips.org> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Probing non-ISA interrupts using the handle_percpu_irq as their handle_irq method may crash the system because handle_percpu_irq does not check IRQ_WAITING. This for example hits the MIPS Qemu configuration. This patch provides two helper functions set_irq_noprobe and set_irq_probe to set rsp. clear the IRQ_NOPROBE flag. The only current caller is MIPS code but this really belongs into generic code. As an aside, interrupt probing these days has become a mostly obsolete if not dangerous art. I think Linux interrupts should be changed to default to non-probing but that's subject of this patch. Signed-off-by: Ralf Baechle include/linux/irq.h | 3 +++ kernel/irq/chip.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) Index: linux-mips/include/linux/irq.h =================================================================== --- linux-mips.orig/include/linux/irq.h +++ linux-mips/include/linux/irq.h @@ -367,6 +367,9 @@ set_irq_chained_handler(unsigned int irq __set_irq_handler(irq, handle, 1, NULL); } +extern void set_irq_noprobe(unsigned int irq); +extern void set_irq_probe(unsigned int irq); + /* Handle dynamic irq creation and destruction */ extern int create_irq(void); extern void destroy_irq(unsigned int irq); Index: linux-mips/kernel/irq/chip.c =================================================================== --- linux-mips.orig/kernel/irq/chip.c +++ linux-mips/kernel/irq/chip.c @@ -589,3 +589,39 @@ set_irq_chip_and_handler_name(unsigned i set_irq_chip(irq, chip); __set_irq_handler(irq, handle, 0, name); } + +void __init set_irq_noprobe(unsigned int irq) +{ + struct irq_desc *desc; + unsigned long flags; + + if (irq >= NR_IRQS) { + printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq); + + return; + } + + desc = irq_desc + irq; + + spin_lock_irqsave(&desc->lock, flags); + desc->status |= IRQ_NOPROBE; + spin_unlock_irqrestore(&desc->lock, flags); +} + +void __init set_irq_probe(unsigned int irq) +{ + struct irq_desc *desc; + unsigned long flags; + + if (irq >= NR_IRQS) { + printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq); + + return; + } + + desc = irq_desc + irq; + + spin_lock_irqsave(&desc->lock, flags); + desc->status &= ~IRQ_NOPROBE; + spin_unlock_irqrestore(&desc->lock, flags); +}