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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E6D0C433EF for ; Thu, 14 Apr 2022 12:06:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242990AbiDNMIw (ORCPT ); Thu, 14 Apr 2022 08:08:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229849AbiDNMIr (ORCPT ); Thu, 14 Apr 2022 08:08:47 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B86001D31F; Thu, 14 Apr 2022 05:06:19 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 277DECE2964; Thu, 14 Apr 2022 12:06:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 628A5C385A8; Thu, 14 Apr 2022 12:06:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649937976; bh=OjbL4muRDkOt6F6rfV+YiLlU4i04iYHzOjNRTKx5cFY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=g7NcLM1WodiK591dQtMx9tWl1D1q2VMOyVrXyjWHVMPsUkrfr/lb2EDzJE3jUsRng DPw0LNXUij8eMPsu576KrL2CgJhRatlMvQtqOZ4qYLBd3+OGQYvTuZPgxbL8DZStiN lZt9TaBTAaa4fh+y24R2QgxHxQu+MXsAMfe6sDwOojNdc/Z03nlYQAY+UXnWajhYcb 2gCwS3CtXbxWnyHUas+/k8/cvsqwc7juBzcZtlLfecBvMyr821yQhJ86N6j1Cgvz/2 z6KtiMBJ5IVZKdgHd/UwRWq0Qra96VwkUOCGm9sMPwJlEd4Iz/NJYFuAwN/FeD5Nl6 klTe20zefWpOw== Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1neyEo-004HEt-05; Thu, 14 Apr 2022 13:06:14 +0100 Date: Thu, 14 Apr 2022 13:06:13 +0100 Message-ID: <875ynbc1je.wl-maz@kernel.org> From: Marc Zyngier To: Tianjia Zhang Cc: Will Deacon , Catalin Marinas , Jonathan Corbet , Joey Gouly , Vincenzo Frascino , Mark Brown , Arnd Bergmann , Anshuman Khandual , Fuad Tabba , Mark Rutland , Vladimir Murzin , James Morse , Suzuki K Poulose , Mathieu Poirier , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64/sme: Add hwcap for Scalable Matrix Extension In-Reply-To: <20220414115544.36204-1-tianjia.zhang@linux.alibaba.com> References: <20220414115544.36204-1-tianjia.zhang@linux.alibaba.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: tianjia.zhang@linux.alibaba.com, will@kernel.org, catalin.marinas@arm.com, corbet@lwn.net, joey.gouly@arm.com, Vincenzo.Frascino@arm.com, broonie@kernel.org, arnd@arndb.de, anshuman.khandual@arm.com, tabba@google.com, mark.rutland@arm.com, vladimir.murzin@arm.com, james.morse@arm.com, suzuki.poulose@arm.com, mathieu.poirier@linaro.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 14 Apr 2022 12:55:44 +0100, Tianjia Zhang wrote: > > Allow userspace to detect support for SME (Scalable Matrix Extension) > by providing a hwcap for it, using the official feature name FEAT_SME, > declared in ARM DDI 0487H.a specification. Err, not just that, for sure. What does this patch buys you on its own, given that the kernel doesn't implement anything yet and that all the SME instructions will UNDEF? [1] is the real deal. Thanks, M. [1] https://lore.kernel.org/r/20220408114328.1401034-1-broonie@kernel.org -- Without deviation from the norm, progress is not possible.