From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x22781kIKDpJpS+pxaBQ4oM430X+dzL06GZo/NDWzLtVKa+WqpFfvxTIim3+yihBYYJ8eRHg2 ARC-Seal: i=1; a=rsa-sha256; t=1517256894; cv=none; d=google.com; s=arc-20160816; b=wddxJZSdcWmW3yVJ1qvqP6m7e+ZfDwHsBJ4QESW5jMlI0/agtO9xFvtT6wUzSDQu/h yqGJS4Hv6998lGx9lXAMOiKt1IKrP2LfJsI8Zuh6pI62mIid9NLjDYIJYgufBLtvHYdf RNeVStg4XtDIgErSFx2i+ZLY0U2futQdxOKJpMmS699NmMdzeLMJtFep5mes//s+A5iV Hlwc3+t1udkZKB5+HPgIbPlX8mJMTXF3uSyN8VUu55yUsUef4obtyBzmRBrbM/SDfjo2 TzeObNRsOFwNn/yMzruTLe4wM/kqhUDQMvHw1bMV7c/PnNt76Ur6AecKWwLQScXrsYUr 99Pw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=3sqmQk/ImKtbuViQ8dHhY5tjhc576K9y9kOO0ikbwY4=; b=w9gzcwMRHAfj+/jpqACJggC8rf6WiUF3DZF8ELrF6NJgd4FoDbvO3Uf1mrGA6C0vBj E52P5qTjFNIVacVZ46CzuqpmzYvVbuF9Lv8nuI4f5nArH00T9lQjTcwkWtYaTdfuG4xS FT4eHRVBuNZEIvsArMhWpi0lCtp8xuN5nTLW0sP/nVhAAQedyZmYij2lv3DWMQO96OqN YQvwgfLNbMzBz3zqYYN4LzV7EG+x4+Rr0DR2byRu9M0t/ea6172vELv+upFDwP0cXG+P bjOQZY1gLXAM3mBBpnFzrAJtRVqEOwSqJIij2GDT/ViAr17y6O83Idcc9LHpcVB+4Ql0 1oFA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jia Zhang , Borislav Petkov , Thomas Gleixner , Tony Luck Subject: [PATCH 4.9 57/66] x86/microcode/intel: Extend BDW late-loading further with LLC size check Date: Mon, 29 Jan 2018 13:57:21 +0100 Message-Id: <20180129123842.891116761@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180129123839.842860149@linuxfoundation.org> References: <20180129123839.842860149@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1590958760100707478?= X-GMAIL-MSGID: =?utf-8?q?1590959164982469963?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jia Zhang commit 7e702d17ed138cf4ae7c00e8c00681ed464587c7 upstream. Commit b94b73733171 ("x86/microcode/intel: Extend BDW late-loading with a revision check") reduced the impact of erratum BDF90 for Broadwell model 79. The impact can be reduced further by checking the size of the last level cache portion per core. Tony: "The erratum says the problem only occurs on the large-cache SKUs. So we only need to avoid the update if we are on a big cache SKU that is also running old microcode." For more details, see erratum BDF90 in document #334165 (Intel Xeon Processor E7-8800/4800 v4 Product Family Specification Update) from September 2017. Fixes: b94b73733171 ("x86/microcode/intel: Extend BDW late-loading with a revision check") Signed-off-by: Jia Zhang Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Acked-by: Tony Luck Link: https://lkml.kernel.org/r/1516321542-31161-1-git-send-email-zhang.jia@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/microcode/intel.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -40,6 +40,9 @@ #include #include +/* last level cache size per core */ +static int llc_size_per_core; + /* * Temporary microcode blobs pointers storage. We note here during early load * the pointers to microcode blobs we've got from whatever storage (detached @@ -1053,12 +1056,14 @@ static bool is_blacklisted(unsigned int /* * 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 > 2621440 && 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"); @@ -1125,6 +1130,15 @@ static struct microcode_ops microcode_in .microcode_fini_cpu = microcode_fini_cpu, }; +static int __init calc_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; +} + struct microcode_ops * __init init_intel_microcode(void) { struct cpuinfo_x86 *c = &boot_cpu_data; @@ -1135,6 +1149,8 @@ struct microcode_ops * __init init_intel return NULL; } + llc_size_per_core = calc_llc_size_per_core(c); + return µcode_intel_ops; }