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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 4FD9CCA9EAE for ; Tue, 29 Oct 2019 15:32:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 20B3F20874 for ; Tue, 29 Oct 2019 15:32:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390048AbfJ2Pcp (ORCPT ); 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