From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x225qSCpuWUDKkqkVz0ulIaEi1DXnnR+Y+b4ACSrDdbCdspqNM/tn0J78zNN3LHWXlNu2sXDs ARC-Seal: i=1; a=rsa-sha256; t=1517256540; cv=none; d=google.com; s=arc-20160816; b=rBP7YzG39bp6cq2LTsqjnbH1yqYbqZPJ3lMAg0wAj+m0Px35jd0U0v2yeKJS5dor7p 3YR34g5/7ccUsABPWV+d/Pos4GBGuqzgL0J6LqMWXJju/o43V8gYDEkF2EfLNI8r5PLA QbH7qrfVijTZdH3BvftoHCIz3evkVfEpfspzQxa2HtB4etox36C8qslrDlXEc4LaWFrw P/WyCyEgPKgczJz0T9tPYhl4VPEC6iPxXOSH1BV0gcB3ZEzfkSNoq1hZl/l0hGWjTGHU gMPgNq1BLH336odQlui7t5NtgEEeotjWarm238WfmQirupWI7cwysGUe+YN/7BIgBi7M fA/A== 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=Jc6Awaz2SZPZ1aVqoMKTmofAjapyVsFUktOgglB3k+I=; b=FdI3+P13Zl/tBJab1MdJqTHyZ8ipv4Lje2au0vwZjb2ohqApfVD/fSU9Ah5RzOdUTr Fm85y2h3CDTp4MOG4FicOpncNrSayC7jQpNSM0gf8P/rJMxYiUAfXwqNezC4tUzrzdIh /aKwcIZIkEhTBSD7GZYbvYOoXFo+dC0WaXlFGV+3VDlzdOM0VYM86wn9Urp8HpK+k8XD sIsG3gTlqP5aiqCr+e2EKKcGAkCKyXDSrFMQHLmdBkjM/xOHQKT759e9kVRMPAm1xJpn nb7wCeZ2ScrbRwncnNfFD3sgxKnQVuG5Ex90lXPNRxoQCM2tzKETo+BTRR132r6vjiO+ sAUw== 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 4.4 56/74] x86/microcode/intel: Extend BDW late-loading further with LLC size check Date: Mon, 29 Jan 2018 13:57:01 +0100 Message-Id: <20180129123850.102342648@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180129123847.507563674@linuxfoundation.org> References: <20180129123847.507563674@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?1590958794713189402?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-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 @@ -39,6 +39,9 @@ #include #include +/* last level cache size per core */ +static int llc_size_per_core; + static unsigned long mc_saved_in_initrd[MAX_UCODE_COUNT]; static struct mc_saved_data { unsigned int mc_saved_count; @@ -996,12 +999,14 @@ 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 == 79 && 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"); @@ -1068,6 +1073,15 @@ 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; @@ -1078,6 +1092,8 @@ struct microcode_ops * __init init_intel return NULL; } + llc_size_per_core = calc_llc_size_per_core(c); + return µcode_intel_ops; }