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 mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99A7EC433EF for ; Wed, 2 Mar 2022 16:41:41 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id F076349EFF; Wed, 2 Mar 2022 11:41:40 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id WaobtYd9jkWI; Wed, 2 Mar 2022 11:41:39 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id B551B49F0E; Wed, 2 Mar 2022 11:41:39 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 9B5E449EFF for ; Wed, 2 Mar 2022 11:41:38 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id DLGRAeqf+xSd for ; Wed, 2 Mar 2022 11:41:37 -0500 (EST) Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 7812849ECB for ; Wed, 2 Mar 2022 11:41:37 -0500 (EST) 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 ams.source.kernel.org (Postfix) with ESMTPS id EB7C5B820D8; Wed, 2 Mar 2022 16:41:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8683C004E1; Wed, 2 Mar 2022 16:41:31 +0000 (UTC) Date: Wed, 2 Mar 2022 16:41:27 +0000 From: Catalin Marinas To: Mark Brown Subject: Re: [PATCH v12 11/40] arm64/sme: Identify supported SME vector lengths at boot Message-ID: References: <20220225165923.1474372-1-broonie@kernel.org> <20220225165923.1474372-12-broonie@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220225165923.1474372-12-broonie@kernel.org> Cc: Basant Kumar Dwivedi , Will Deacon , Luis Machado , Szabolcs Nagy , Marc Zyngier , Shuah Khan , linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, Alan Hayward , Shuah Khan , kvmarm@lists.cs.columbia.edu, Salil Akerkar X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Fri, Feb 25, 2022 at 04:58:54PM +0000, Mark Brown wrote: > The vector lengths used for SME are controlled through a similar set of > registers to those for SVE and enumerated using a similar algorithm with > some slight differences due to the fact that unlike SVE there are no > restrictions on which combinations of vector lengths can be supported > nor any mandatory vector lengths which must be implemented. Add a new > vector type and implement support for enumerating it. > > One slightly awkward feature is that we need to read the current vector > length using a different instruction (or enter streaming mode which > would have the same issue and be higher cost). Rather than add an ops > structure we add special cases directly in the otherwise generic > vec_probe_vqs() function, this is a bit inelegant but it's the only > place where this is an issue. > > Signed-off-by: Mark Brown Reviewed-by: Catalin Marinas _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm