Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750854AbXAHPyU (ORCPT ); Mon, 8 Jan 2007 10:54:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750865AbXAHPyU (ORCPT ); Mon, 8 Jan 2007 10:54:20 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:59592 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750854AbXAHPyT (ORCPT ); Mon, 8 Jan 2007 10:54:19 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Linus Torvalds Cc: Tobias Diedrich , Yinghai Lu , Andrew Morton , Adrian Bunk , Andi Kleen , Linux Kernel Mailing List Subject: PATCH 2/4] x86_64 io_apic: Implement irq_from_pin References: <5986589C150B2F49A46483AC44C7BCA490733F@ssvlexmb2.amd.com> <86802c440701022223q418bd141qf4de8ab149bf144b@mail.gmail.com> <20070108005556.GA2542@melchior.yamamaya.is-a-geek.org> Date: Mon, 08 Jan 2007 08:53:52 -0700 In-Reply-To: (Eric W. Biederman's message of "Mon, 08 Jan 2007 08:49:36 -0700") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1555 Lines: 51 Another helper needed for guessing the routing of the timer irq. irq_from_pin looks at the irq_2_pin mapping and figures out which irq is connected to a given apic and pin combination. We need to know this to avoid guessing an apic pin that is already in use by another irq. Despite the nested loops this is O(N) walk through the irq_2_pin data structure. Signed-off-by: Eric W. Biederman --- arch/x86_64/kernel/io_apic.c | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-) diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c index 7365f5f..5ad210f 100644 --- a/arch/x86_64/kernel/io_apic.c +++ b/arch/x86_64/kernel/io_apic.c @@ -262,6 +262,20 @@ static void set_ioapic_affinity_irq(unsigned int irq, cpumask_t mask) } #endif +static int irq_from_pin(int apic, int pin) +{ + int irq; + for (irq = 0; irq < NR_IRQS; irq++) { + struct irq_pin_list *entry = irq_2_pin + irq; + while (entry->next && ((entry->apic != apic) || (entry->pin != pin))) + entry = irq_2_pin + entry->next; + + if ((entry->pin == pin) && (entry->apic == apic)) + return irq; + } + return -1; +} + /* * The common case is 1:1 IRQ<->pin mappings. Sometimes there are * shared ISA-space IRQs, so we have to support them. We are super -- 1.4.4.1.g278f - 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/