Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932216AbeAOFoC (ORCPT + 1 other); Mon, 15 Jan 2018 00:44:02 -0500 Received: from out30-132.freemail.mail.aliyun.com ([115.124.30.132]:58464 "EHLO out30-132.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932098AbeAOFnx (ORCPT ); Mon, 15 Jan 2018 00:43:53 -0500 X-Alimail-AntiSpam: AC=CONTINUE;BC=0.073829|-1;CH=green;FP=0|0|0|0|0|-1|-1|-1;HT=e01e01429;MF=zhang.jia@linux.alibaba.com;NM=1;PH=DS;RN=8;RT=8;SR=0;TI=SMTPD_---0SwbXBvc_1515995015; From: Jia Zhang To: tony.luck@intel.com, bp@alien8.de Cc: mingo@redhat.com, hpa@zytor.com, tglx@linutronix.de, x86@kernel.org, linux-kernel@vger.kernel.org, Jia Zhang Subject: [PATCH 2/2] x86/microcode/intel: Extend BDW late-loading with platform id and LLC check Date: Mon, 15 Jan 2018 13:43:23 +0800 Message-Id: <1515995003-113069-3-git-send-email-zhang.jia@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1515995003-113069-1-git-send-email-zhang.jia@linux.alibaba.com> References: <1515995003-113069-1-git-send-email-zhang.jia@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: The commit b94b73733171 ("x86/microcode/intel: Extend BDW late-loading with a revision check") reduces the impact of erratum BDF90 for Broadwell process model. Now, the impact can be reduced further through adding the checks for platform id and the size of LLC per core. This fix is useful to reduce the impact for microcode update launched by BIOS with a must machine reset. For more details, see erratum BDF90 in document #334165 (Intel Xeon Processor E7-8800/4800 v4 Product Family Specification Update) from September 2017. Signed-off-by: Jia Zhang --- arch/x86/kernel/cpu/microcode/intel.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c index d9e460f..8bf09eb 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -906,18 +906,30 @@ static int get_ucode_fw(void *to, const void *from, size_t n) return 0; } +static int llc_size_per_core(struct cpuinfo_x86 *c) +{ + u64 llc_size = c->x86_cache_size * 1024; + + do_div(llc_size, c->x86_max_cores); + + return (int)llc_size; +} + static bool is_blacklisted(unsigned int cpu) { struct cpuinfo_x86 *c = &cpu_data(cpu); /* * Late loading on model 79 with microcode revision less than 0x0b000021 - * may result in a system hang. This behavior is documented in item - * BDF90, #334165 (Intel Xeon Processor E7-8800/4800 v4 Product Family). + * and LLC size per core bigger than 2.5MB may result in a system hang. + * 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 && + llc_size_per_core(c) > 2621440 && + c->platform_id == 0xef && c->microcode < 0x0b000021) { pr_err_once("Erratum BDF90: late loading with revision < 0x0b000021 (0x%x) disabled.\n", c->microcode); pr_err_once("Please consider either early loading through initrd/built-in or a potential BIOS update.\n"); -- 1.8.3.1