Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755112AbYCXVtK (ORCPT ); Mon, 24 Mar 2008 17:49:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753514AbYCXVs5 (ORCPT ); Mon, 24 Mar 2008 17:48:57 -0400 Received: from byss.tchmachines.com ([208.76.80.75]:56321 "EHLO byss.tchmachines.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752804AbYCXVs4 (ORCPT ); Mon, 24 Mar 2008 17:48:56 -0400 Date: Mon, 24 Mar 2008 14:48:36 -0700 From: Ravikiran G Thirumalai To: Ingo Molnar Cc: Yinghai Lu , Andrew Morton , linux-kernel@vger.kernel.org, Glauber de Oliveira Costa , shai@scalex86.org Subject: Re: [patch 4/4] x86: apic_is_clustered_box to indicate unsynched TSC's on multiboard vSMP systems Message-ID: <20080324214836.GA6045@localdomain> References: <20080320073740.GA9414@localdomain> <20080320074508.GE9414@localdomain> <86802c440803200053m1b0928a9q6567d8c619fa7a2f@mail.gmail.com> <20080320190240.GB6085@localdomain> <20080321091542.GE20420@elte.hu> <20080321185225.GA23139@localdomain> <20080321185821.GE6571@elte.hu> <20080322185948.GD23139@localdomain> <20080322200251.GB5508@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080322200251.GB5508@elte.hu> User-Agent: Mutt/1.5.13 (2006-08-11) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - byss.tchmachines.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - scalex86.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2218 Lines: 92 On Sat, Mar 22, 2008 at 09:02:51PM +0100, Ingo Molnar wrote: > >* Ravikiran G Thirumalai wrote: > >> OK. Something like this? > >yeah. > >small nit: > >> +int is_vsmp_box(void) >> +{ >> + if (is_vsmp != -1) >> + return is_vsmp; >> + else { >> + printk("ScaleMP vSMPowered system detection called too early!\n"); >> + return 0; >> + } >> } > >since this is an "impossible" scenario, just stick in a WARN_ON_ONCE(). > Sure. Here's the modified patch. vSMP detection: Access pci config space early in boot to detect if the system is a vSMPowered box, and cache the result in a flag, so that is_vsmp_box() retrieves the value of the flag always. Signed-off-by; Ravikiran Thirumalai Index: linux.git.trees/arch/x86/kernel/vsmp_64.c =================================================================== --- linux.git.trees.orig/arch/x86/kernel/vsmp_64.c 2008-03-21 13:15:17.000000000 -0700 +++ linux.git.trees/arch/x86/kernel/vsmp_64.c 2008-03-24 13:57:09.387437626 -0700 @@ -108,25 +108,34 @@ static void __init set_vsmp_pv_ops(void) #endif #ifdef CONFIG_PCI -static int vsmp = -1; +static int is_vsmp = -1; -int is_vsmp_box(void) +static void __init detect_vsmp_box(void) { - if (vsmp != -1) - return vsmp; + is_vsmp = 0; - vsmp = 0; if (!early_pci_allowed()) - return vsmp; + return; - /* Check if we are running on a ScaleMP vSMP box */ + /* Check if we are running on a ScaleMP vSMPowered box */ if (read_pci_config(0, 0x1f, 0, PCI_VENDOR_ID) == (PCI_VENDOR_ID_SCALEMP | (PCI_DEVICE_ID_SCALEMP_VSMP_CTL << 16))) - vsmp = 1; + is_vsmp = 1; +} - return vsmp; +int is_vsmp_box(void) +{ + if (is_vsmp != -1) + return is_vsmp; + else { + WARN_ON_ONCE(1); + return 0; + } } #else +static int __init detect_vsmp_box(void) +{ +} int is_vsmp_box(void) { return 0; @@ -135,6 +144,7 @@ int is_vsmp_box(void) void __init vsmp_init(void) { + detect_vsmp_box(); if (!is_vsmp_box()) return; -- 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/