Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753381Ab0FHFuP (ORCPT ); Tue, 8 Jun 2010 01:50:15 -0400 Received: from mga09.intel.com ([134.134.136.24]:49089 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752428Ab0FHFuO (ORCPT ); Tue, 8 Jun 2010 01:50:14 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.53,383,1272870000"; d="scan'208";a="524883383" Date: Mon, 7 Jun 2010 22:50:10 -0700 From: jacob pan To: ebiederm@xmission.com (Eric W. Biederman) Cc: Alan Cox , Arjan van de Ven , LKML , "H. Peter Anvin" , Ingo Molnar , Feng Tang , Len Brown Subject: Re: [PATCH] x86/sfi: fix ioapic gsi range Message-ID: <20100607225010.342e2fab@jacob-laptop> In-Reply-To: References: <1275952044-27996-1-git-send-email-jacob.jun.pan@linux.intel.com> Organization: OTC X-Mailer: Claws Mail 3.7.4 (GTK+ 2.20.1; i486-pc-linux-gnu) Mime-Version: 1.0 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 Content-Length: 1506 Lines: 34 > > Background: > > In Moorestown/Medfield platforms, there is no legacy IRQs, all gsis > > and irqs are one to one mapped, including those < 16. Specifically, > > IRQ0 and IRQ1 are used for per-cpu timers. So without this patch, > > IOAPIC pin to IRQ mapping is off by one. > > The patch looks mostly reasonable the comment is wrong. > > You may not use a 1-1 mapping if you don't have legacy irqs. Linux > irqs 0-15 are the ISA irqs you may not use those irq numbers for > something different on any architecture, but especially not on x86. > The gsi numbers are firmware specific and you may treat however you > want. [jacob pan] If we don't have ISA irqs, why can't we have gsi# = irq# for the legacy IRQ range? On Moorestown, we are re-using legacy irqs. e.g. sh-4.0# cat /proc/interrupts CPU0 CPU1 0: 1512 0 IO-APIC-edge apbt0 1: 0 1482 IO-APIC-edge apbt1 9: 0 0 IO-APIC-fasteoi dw_spi 10: 0 0 IO-APIC-fasteoi mrst_i2c 11: 0 0 IO-APIC-fasteoi mrst_i2c 12: 0 0 IO-APIC-fasteoi mrst_i2c 23: 0 0 IO-APIC-fasteoi intel_scu_ipc 27: 21 0 IO-APIC-fasteoi -- 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/