Received: by 2002:a17:90a:8504:0:0:0:0 with SMTP id l4csp4849455pjn; Tue, 29 Oct 2019 08:36:29 -0700 (PDT) X-Google-Smtp-Source: APXvYqy/rp7oRI74D8wEKepwaopn2mMdjK5PFJgrtTMGrKhVAlUeEut2XxXhu/j+XOuqJWq9pF5G X-Received: by 2002:a17:906:743:: with SMTP id z3mr3858654ejb.142.1572363389401; Tue, 29 Oct 2019 08:36:29 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1572363389; cv=none; d=google.com; s=arc-20160816; b=GIAO/en4TBeNVwL2bvPwz9JuMl1Q/ewCsyklNnXRCZgopOEg/OK0ZkfUGg8/br0WBm WBuzY4HSgCx/6r7y8q/3LszJE/bLgQNg+4D/J/WC6PttB/DasMSSWv9uHchQ9EhSBg71 NdQ+ba2256G2sDCsoy0GRcrzjd3MHYT65bs6uHXnujLTDK31V+4jonVv38CS3wjUr6TS KyaSpPhWJHaQlB0VS0olb6q8m3OHC7l+i3JfYoCCiS7rGfaxtmaaA5pVYP6CG2wZ2FZ8 YbP28GLPmxrXTnpnme26mV5qED+dkxtDXElCBe+NGIor8eWKfocAVlsl9TaghOP8YRLX FYKg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:from:references:cc:to:subject; bh=kpPiRTdS+c6bnmcrtrt/rDXnTA4e7H4l8rNBAttBOQU=; b=f7xG7DhqaAngdv8nt4SWsg2LLO37X4on5Af1DT5cS5DBpVsDFuZPbtXV+0x2OHoTJv fy741wC8t9My/9clDM2eGk5lO/tVaLKR2kw9NYhxFtS/+6P1VXno+IJ9XyZSCZR0rRjz I3LoYEWguoaJWTF8ZQtp6iugNRkdU4qjZpeTparDPt5Of3ieUj98qRV81Cx7x36pqzcR xaOXlTFIbPE7UKuh3hn7SJkXqde+yE1ICs9BB4coayN1p1gSvV715RWhalvVtwstSNQc zteMY3QMdruDjOBSS00XpXb/9i9XsBDHD6K9ecky7KevWjvgdoSspl3bH7PMzk/F/HrK d1TA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id s28si7673837edc.98.2019.10.29.08.36.06; Tue, 29 Oct 2019 08:36:29 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390027AbfJ2Pcp (ORCPT + 99 others); Tue, 29 Oct 2019 11:32:45 -0400 Received: from foss.arm.com ([217.140.110.172]:53424 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389319AbfJ2Pco (ORCPT ); Tue, 29 Oct 2019 11:32:44 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 385511F1; Tue, 29 Oct 2019 08:32:44 -0700 (PDT) Received: from [10.1.196.50] (e108454-lin.cambridge.arm.com [10.1.196.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6B1733F71F; Tue, 29 Oct 2019 08:32:43 -0700 (PDT) Subject: Re: [PATCH] arm64: cpufeature: Export Armv8.6 Matrix feature to userspace To: Will Deacon Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, suzuki.poulose@arm.com, Dave.Martin@arm.com References: <20191025171056.30641-1-julien.grall@arm.com> <20191029111517.GE11590@willie-the-truck> <20191029113606.GB12103@willie-the-truck> From: Julien Grall Message-ID: <6f175c28-1ac0-3da0-bbfa-a811a4adfed7@arm.com> Date: Tue, 29 Oct 2019 15:32:42 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191029113606.GB12103@willie-the-truck> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Will, On 29/10/2019 11:36, Will Deacon wrote: > On Tue, Oct 29, 2019 at 11:26:41AM +0000, Julien Grall wrote: >> On 29/10/2019 11:15, Will Deacon wrote: >>> On Fri, Oct 25, 2019 at 06:10:56PM +0100, Julien Grall wrote: >>>> This patch provides support for reporting the presence of Armv8.6 >>>> Matrix and its optional features to userspace. >>> >>> Are you sure this is 8.6 and not earlier? >> >> This was introduced by Armv8.6 see [1] but allowed to be used by Armv8.2 and >> onwards. > > That doesn't mean an awful lot though, especially then the features are > referred to in the docs as things like "ARMv8.2-F64MM". It is arguable. The feature were announced for Armv8.6 but made available for previous release. Anyway, I can remove the "Armv8.6" bits if that's the concern. Cheers, -- Julien Grall