From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [RESEND,2/5] x86/MCE: Handle MCA controls in a per_cpu way From: Borislav Petkov Message-Id: <20190409203412.GE6150@zn.tnic> Date: Tue, 9 Apr 2019 22:34:12 +0200 To: "Ghannam, Yazen" Cc: "linux-edac@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "tony.luck@intel.com" , "x86@kernel.org" List-ID: T24gTW9uLCBBcHIgMDgsIDIwMTkgYXQgMDY6NTU6NTlQTSArMDAwMCwgR2hhbm5hbSwgWWF6ZW4g d3JvdGU6Cj4gV2UgYWxyZWFkeSBoYXZlIHRoZSBjYXNlIHdoZXJlIHNvbWUgYmFua3MgYXJlIG5v dCBpbml0aWFsaXplZCBlaXRoZXIKPiBkdWUgdG8gcXVpcmtzIG9yIGJlY2F1c2UgdGhleSBhcmUg UmVhZC1hcy1aZXJvLCBidXQgd2UgZG9uJ3QgdHJ5IHRvCj4gc2tpcCBjcmVhdGluZyB0aGVpciBm aWxlcy4gV2l0aCB0aGlzIGZ1bGwgc2V0IChzZWUgcGF0Y2ggNSksIGFuIHVudXNlZAo+IGJhbmsg d2lsbCByZXR1cm4gYSBjb250cm9sIHZhbHVlIG9mIDAuCgpTbyBzZXRfYmFuaygpIGlzIGNoYW5n ZWQgdG8gZG86CgpAQCAtMjA4OCw3ICsyMDk3LDcgQEAgc3RhdGljIHNzaXplX3Qgc2V0X2Jhbmso c3RydWN0IGRldmljZSAqcywgc3RydWN0IGRldmljZV9hdHRyaWJ1dGUgKmF0dHIsCiAgICAgICAg aWYgKGtzdHJ0b3U2NChidWYsIDAsICZuZXcpIDwgMCkKICAgICAgICAgICAgICAgIHJldHVybiAt RUlOVkFMOwoKLSAgICAgICBpZiAoYmFuayA+PSBtY2FfY2ZnLmJhbmtzKQorICAgICAgIGlmIChi YW5rID49IHBlcl9jcHUobnVtX2JhbmtzLCBzLT5pZCkpCiAgICAgICAgICAgICAgICByZXR1cm4g LUVJTlZBTDsKCgpIb3cgd291bGQgdGhhdCB3b3JrIGlmIHRoZSBkaXNhYmxlZC9ub3QtcHJlc2Vu dCBiYW5rIGlzIGluIHRoZSBtaWRkbGU/ClRoZSBvbGQgZXhhbXBsZTogYmFuazMgb24gQ1BVNS4K Cj4gV291bGQgdGhhdCBiZSBzdWZmaWNpZW50IHRvIGluZGljYXRlIHRoYXQgYSBiYW5rIGlzIG5v dCB1c2VkPwoKV2VsbCwgaXQgc2hvdWxkIG5vdCBhbGxvdyBmb3IgYW55IGNvbnRyb2wgYml0cyB0 byBiZSBzZXQgYW5kIGl0IHNob3VsZApoYXZlIHRoZSBwcm9wZXIgYmFuayBudW1iZXIuCgo+IEJ1 dCBJIGRvIGhhdmUgYSBjb3VwbGUgb2YgdGhvdWdodHM6Cgo+IDEpIFdpbGwgbWlzc2luZyBiYW5r cyBjb25mdXNlIHVzZXJzPyBBcyBtZW50aW9uZWQsIHdlIGFscmVhZHkgaGF2ZSB0aGUKPiBjYXNl IG9mIHVudXNlZC91bmluaXRpYWxpemVkIGJhbmtzIHRvZGF5LCBidXQgd2UgZG9uJ3Qgc2tpcCB0 aGVpciBmaWxlCj4gY3JlYXRpb24uIGEpIFdpbGwgdGhpcyBhZmZlY3QgYW55IHVzZXJzcGFjZSB0 b29scz8KCkkgZ3Vlc3MgaXQgd291bGQgYmUgZWFzaWVyIGlmIHdlIGtlZXAgY3JlYXRpbmcgYWxs IGZpbGVzIGJ1dCBkZW5vdGUgcHJvcGVybHkKd2hpY2ggYmFua3MgYXJlIGRpc2FibGVkLgoKPiAy KSBJcyB0aGUgYWRkZWQgY29tcGxleGl0eSBmb3IgZmlsZSBjcmVhdGlvbi9kZXN0cnVjdGlvbiB3 b3J0aCBpdD8gQXMKPiBtZW50aW9uZWQsIHRoZSBmaWxlIHdpbGwgcmV0dXJuIDAgZm9yIHVudXNl ZC91bmluaXRpYWxpemVkIGJhbmtzLgoKWWVhaC4KClRoeC4K From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92DFEC10F0E for ; 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a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1554842061; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=9pkiibSoE1UtncS1t4SALzcqhoYEOsusZM3elMz8lWU=; b=FihTCBNeWMvliyh2g7ngcgErRE+xcnI7X5F1Yig3UDVessMKky9GE5TwXRxMHd7IenWgru 78WrokkV1PCoyKgldcCPALeNykPMpMrvtn4K1uuLeozh4zGSnclUMn51onRl4i5WfAYFcL Li2RUJCLAaBN3gKjI/rqI+Tsiuc3jck= Date: Tue, 9 Apr 2019 22:34:12 +0200 From: Borislav Petkov To: "Ghannam, Yazen" Cc: "linux-edac@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "tony.luck@intel.com" , "x86@kernel.org" Subject: Re: [PATCH RESEND 2/5] x86/MCE: Handle MCA controls in a per_cpu way Message-ID: <20190409203412.GE6150@zn.tnic> References: <20190408141205.12376-1-Yazen.Ghannam@amd.com> <20190408141205.12376-3-Yazen.Ghannam@amd.com> <20190408175142.GK15689@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-edac-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-edac@vger.kernel.org Message-ID: <20190409203412._IgSFssiVpJWK_Y8PwIM-vNShLtH8WQqWSpT-TYKbRc@z> On Mon, Apr 08, 2019 at 06:55:59PM +0000, Ghannam, Yazen wrote: > We already have the case where some banks are not initialized either > due to quirks or because they are Read-as-Zero, but we don't try to > skip creating their files. With this full set (see patch 5), an unused > bank will return a control value of 0. So set_bank() is changed to do: @@ -2088,7 +2097,7 @@ static ssize_t set_bank(struct device *s, struct device_attribute *attr, if (kstrtou64(buf, 0, &new) < 0) return -EINVAL; - if (bank >= mca_cfg.banks) + if (bank >= per_cpu(num_banks, s->id)) return -EINVAL; How would that work if the disabled/not-present bank is in the middle? The old example: bank3 on CPU5. > Would that be sufficient to indicate that a bank is not used? Well, it should not allow for any control bits to be set and it should have the proper bank number. > But I do have a couple of thoughts: > 1) Will missing banks confuse users? As mentioned, we already have the > case of unused/uninitialized banks today, but we don't skip their file > creation. a) Will this affect any userspace tools? I guess it would be easier if we keep creating all files but denote properly which banks are disabled. > 2) Is the added complexity for file creation/destruction worth it? As > mentioned, the file will return 0 for unused/uninitialized banks. Yeah. Thx. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.