From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754764Ab1EKQdb (ORCPT ); Wed, 11 May 2011 12:33:31 -0400 Received: from mga01.intel.com ([192.55.52.88]:57680 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752910Ab1EKQdO (ORCPT ); Wed, 11 May 2011 12:33:14 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.64,353,1301900400"; d="scan'208";a="894339" Date: Wed, 11 May 2011 22:19:45 -0400 From: Youquan Song To: mingo@elte.hu Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, mingo@elte.hu, tglx@linutronix.de, hpa@zytor.com, hpa@linux.intel.com, suresh.b.siddha@intel.com, yong.y.wang@linux.intel.com, joe@perches.com, jbaron@redhat.com, trenn@suse.de, kent.liu@intel.com, chaohong.guo@intel.com, Youquan Song Subject: Re: [PATCH v4 1/2] apic: Fix error interrupt report at all APs Message-ID: <20110512021945.GB19070@linux-youquan.bj.intel.com> References: <1303402963-17738-1-git-send-email-youquan.song@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1303402963-17738-1-git-send-email-youquan.song@intel.com> 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 Hi Ingo, Below is the updated description. If it looks good, please take it since the first patch "x86, apic: Print verbose error interrupt reason on apic=debug" in the patchset already accepted in -tip. Thanks -Youquan On Fri, Apr 22, 2011 at 12:22:43AM +0800, Youquan Song wrote: > This patch fixes a bug reported from customer, who found many unreasonable error > interrupts reported on all APs during the system boot stage. > > According to Chapter 10 of Intel Software Developer Manual Volume 3A, Local APIC > may signal an illegal vector error when an LVT entry is set as an illegal > vector value (0~15) under FIXED delivery mode (bits 8-11 is 0), regardless of > whether the mask bit is set or an interrupt actually happen. These errors are > seen as error interrupts. > > The initial value of thermal LVT entries on all APs always reads 0x10000 because > APs are woken up by BSP issuing INIT-SIPI-SIPI sequence to them and LVT > registers are reset to 0s except for the mask bits which are set to 1s when APs > receive INIT IPI. When BIOS take over the thermal throttling interrupt, LVT > thermal deliver mode should be SMI and it is required to restore AP's LVT > thermal monitor register. > > This issue happens when BIOS do not take over thermal throttling interrupt, > AP's LVT thermal monitor register will be restored to 0x10000 which means vector > 0 and fixed deliver mode, so all APs will signal illegal vector error > interrupt. This patch check if interrupt delivery mode is not fixed mode before > restore AP's LVT thermal monitor register. > > Signed-off-by: Youquan Song > Acked-by: Suresh Siddha > Acked-by: Yong Wang > --- > arch/x86/include/asm/apicdef.h | 1 + > arch/x86/kernel/cpu/mcheck/therm_throt.c | 12 +++++++----- > 2 files changed, 8 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/include/asm/apicdef.h b/arch/x86/include/asm/apicdef.h > index d87988b..34595d5 100644 > --- a/arch/x86/include/asm/apicdef.h > +++ b/arch/x86/include/asm/apicdef.h > @@ -78,6 +78,7 @@ > #define APIC_DEST_LOGICAL 0x00800 > #define APIC_DEST_PHYSICAL 0x00000 > #define APIC_DM_FIXED 0x00000 > +#define APIC_DM_FIXED_MASK 0x00700 > #define APIC_DM_LOWEST 0x00100 > #define APIC_DM_SMI 0x00200 > #define APIC_DM_REMRD 0x00300 > diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c > index 6f8c5e9..22c212a 100644 > --- a/arch/x86/kernel/cpu/mcheck/therm_throt.c > +++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c > @@ -446,18 +446,20 @@ void intel_init_thermal(struct cpuinfo_x86 *c) > */ > rdmsr(MSR_IA32_MISC_ENABLE, l, h); > > + h = lvtthmr_init; > /* > * The initial value of thermal LVT entries on all APs always reads > * 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI > * sequence to them and LVT registers are reset to 0s except for > * the mask bits which are set to 1s when APs receive INIT IPI. > - * Always restore the value that BIOS has programmed on AP based on > - * BSP's info we saved since BIOS is always setting the same value > - * for all threads/cores > + * If BIOS take over the thermal interrupt and set its interrupt > + * delivery mode to SMI not fixed, it restore the value that BIOS has > + * programmed on AP based on BSP's info we saved since BIOS is always > + * setting the same value for all threads/cores. > */ > - apic_write(APIC_LVTTHMR, lvtthmr_init); > + if ((h & APIC_DM_FIXED_MASK) != APIC_DM_FIXED) > + apic_write(APIC_LVTTHMR, lvtthmr_init); > > - h = lvtthmr_init; > > if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) { > printk(KERN_DEBUG > -- > 1.6.4.2 > > -- > 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/ >