From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751847AbdL0Ewk convert rfc822-to-8bit (ORCPT ); Tue, 26 Dec 2017 23:52:40 -0500 Received: from mga04.intel.com ([192.55.52.120]:56234 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751784AbdL0Ewj (ORCPT ); Tue, 26 Dec 2017 23:52:39 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.45,462,1508828400"; d="scan'208";a="190227064" From: "Luck, Tony" To: Jia Zhang CC: "bp@alien8.de" , "tglx@linutronix.de" , "mingo@redhat.com" , "hpa@zytor.com" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v4] x86/microcode/intel: Blacklist the specific BDW-EP for late loading Thread-Topic: [PATCH v4] x86/microcode/intel: Blacklist the specific BDW-EP for late loading Thread-Index: AQHTfkcAHit/9nT3GEWJVDJ0sgxuJaNWoHoq Date: Wed, 27 Dec 2017 04:52:37 +0000 Message-ID: <10DA9229-676A-4780-AD11-120FA7855274@intel.com> References: <1514292147-101928-1-git-send-email-qianyue.zj@alibaba-inc.com> In-Reply-To: <1514292147-101928-1-git-send-email-qianyue.zj@alibaba-inc.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When all the patch issues are ironed out consider this Acked-by: Tony Luck I was planning to hunt down the erratum when I got back from vacation in the new year. Sent from my iPhone > On Dec 26, 2017, at 04:42, Jia Zhang wrote: > > Instead of blacklisting all types of Broadwell processor when running > a late loading, only BDW-EP (signature 0x406f1, aka family 6, model 79, > stepping 1) with the microcode version less than 0x0b000021 needs to > be blacklisted. > > The erratum is documented in the the public documentation #334165 (See > the item BDF90 for details). > > Signed-off-by: Jia Zhang > --- > arch/x86/kernel/cpu/microcode/intel.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c > index 8ccdca6..79cad85 100644 > --- a/arch/x86/kernel/cpu/microcode/intel.c > +++ b/arch/x86/kernel/cpu/microcode/intel.c > @@ -910,8 +910,16 @@ static bool is_blacklisted(unsigned int cpu) > { > struct cpuinfo_x86 *c = &cpu_data(cpu); > > - if (c->x86 == 6 && c->x86_model == INTEL_FAM6_BROADWELL_X) { > - pr_err_once("late loading on model 79 is disabled.\n"); > + /* > + * The Broadwell-EP processor with the microcode version less > + * then 0x0b000021 may result in system hang when running a late > + * loading. This behavior is documented in item BDF90, #334165 > + * (Intel Xeon Processor E7-8800/4800 v4 Product Family). > + */ > + if (c->x86 == 6 && c->x86_model == INTEL_FAM6_BROADWELL_X && > + c->x86_mask == 0x01 && c->microcode < 0x0b000021) { > + pr_err_once("late loading on cpu (sig 0x406f1) is disabled " > + "due to erratum causing system hang.\n"); > return true; > } > > -- > 1.8.3.1 >