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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A07C5C433F5 for ; Wed, 2 Mar 2022 16:42:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=WEVOrwct0nkBtg/FoH48YIjGK+oWxmdU+qLaZb9Tngc=; b=3EPpDenr7brR+e YSlvR6L1NhqUioN95VvbSPRCK9W7KyzH4QcuLttHqDqTlIL0jlbpV/ldVZrBjck1Mx9nxTWfiQQ9R Ot59zN/27fBD9OgCmQo1gVOsgp8EhcoAP51quVJ5yJoxbtMzwPl98S9fLCj1AsdJ7WrFQZCI6Xnvd jJiw3Bx7yHEbyBdfCV2CdGI5jUhx9bqxWWhn2r7SGd5i/f6zEltgbOII7g0Gj4YRBbDXo6BPe+e3X OO8ZHLKuhJHsmjMFCoMtaYaVA5kO3S7x2JxlKegIq/jX7RskmvG2ypoFY7KOScIJgx1n0/d/Rdahs cabIF4RaGhRSxfGEhOQQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nPS2m-003NIb-Rs; Wed, 02 Mar 2022 16:41:40 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nPS2j-003NHa-Bt for linux-arm-kernel@lists.infradead.org; Wed, 02 Mar 2022 16:41:38 +0000 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 Cc: Will Deacon , Marc Zyngier , Shuah Khan , Shuah Khan , Alan Hayward , Luis Machado , Salil Akerkar , Basant Kumar Dwivedi , Szabolcs Nagy , James Morse , Alexandru Elisei , Suzuki K Poulose , linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, kvmarm@lists.cs.columbia.edu 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> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220302_084137_560579_2DF7DE08 X-CRM114-Status: GOOD ( 16.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel