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 D1CBCC47258 for ; Tue, 23 Jan 2024 15:50:03 +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=GlrhBpigMgzUWlKiEUFWeJEH3iOGCtGEgG9JwqtedhQ=; b=d2uqKDMtubSaZz ZgxDmvbXTDksO9B92KxHGKUiyeogSHzycZSTSX36vf6sJeNCWIkd/CDweLSETlWJ7yiFnPnnWXM5Q dJx3ALJorf6AIoWY5GGwyFNxw3VzQu5TExKNBpMlehS7B/4xLMqvoWmMi0YkrVEHwGJEn9lA4cIYP 9F7Us6I4+CUEG5Evd0YxD/uirrikIXuY3zmQoFFQ3mnNz1GUYz6NCetIUtNvzOfTaMgVXOPN4hT7h o65xveXRk8MtEY3lQitnCPe2X/VbM4dFOlTvo1VGmydN3qLhgxe3mHDCYtTvuwBVA7qoVhixupZcv 1qIl7rD+QWSX4SXWilhQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rSJ1t-00H88j-1w; Tue, 23 Jan 2024 15:49:37 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rSJ1q-00H880-0a for linux-arm-kernel@lists.infradead.org; Tue, 23 Jan 2024 15:49:35 +0000 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 CD0A41FB; Tue, 23 Jan 2024 07:50:15 -0800 (PST) Received: from e133380.arm.com (e133380.arm.com [10.1.197.58]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6E6C03F5A1; Tue, 23 Jan 2024 07:49:29 -0800 (PST) Date: Tue, 23 Jan 2024 15:49:27 +0000 From: Dave Martin To: Mark Brown Cc: Catalin Marinas , Will Deacon , Jonathan Corbet , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Edmund Grimley-Evans Subject: Re: [PATCH 3/4] arm64/fp: Clarify effect of setting an unsupported system VL Message-ID: References: <20240122-arm64-sve-sme-doc-v1-0-3d492e45265b@kernel.org> <20240122-arm64-sve-sme-doc-v1-3-3d492e45265b@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240122-arm64-sve-sme-doc-v1-3-3d492e45265b@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240123_074934_265024_99B43837 X-CRM114-Status: GOOD ( 19.56 ) 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 Mon, Jan 22, 2024 at 08:41:53PM +0000, Mark Brown wrote: > The documentation for system vector length configuration does not cover all > cases where unsupported values are written, tighten it up. > > Reported-by: Edmund Grimley-Evans > Signed-off-by: Mark Brown > --- > Documentation/arch/arm64/sme.rst | 5 ++--- > Documentation/arch/arm64/sve.rst | 5 ++--- > 2 files changed, 4 insertions(+), 6 deletions(-) > > diff --git a/Documentation/arch/arm64/sme.rst b/Documentation/arch/arm64/sme.rst > index 3133d0e91b48..ba0a5e5b2523 100644 > --- a/Documentation/arch/arm64/sme.rst > +++ b/Documentation/arch/arm64/sme.rst > @@ -379,9 +379,8 @@ The regset data starts with struct user_za_header, containing: > /proc/sys/abi/sme_default_vector_length > > Writing the text representation of an integer to this file sets the system > - default vector length to the specified value, unless the value is greater > - than the maximum vector length supported by the system in which case the > - default vector length is set to that maximum. > + default vector length to the specified value rounded to a supported value > + using the same rules as for setting vector length via prctl(). Do parallel changes need to be made in sve.rst? (There seems to be so much duplication and copy-paste between these files that I wonder whether it would make sense to merge them... but that's probably a separate discussion.) Nit: is it better to name the prctl here than just to say prctl()? That would be easier for the reader to cross-reference. > > The result can be determined by reopening the file and reading its > contents. > diff --git a/Documentation/arch/arm64/sve.rst b/Documentation/arch/arm64/sve.rst > index b45a2da19bf1..b923727ff4b9 100644 > --- a/Documentation/arch/arm64/sve.rst > +++ b/Documentation/arch/arm64/sve.rst > @@ -423,9 +423,8 @@ The regset data starts with struct user_sve_header, containing: > /proc/sys/abi/sve_default_vector_length > > Writing the text representation of an integer to this file sets the system > - default vector length to the specified value, unless the value is greater > - than the maximum vector length supported by the system in which case the > - default vector length is set to that maximum. > + default vector length to the specified value rounded to a supported value > + using the same rules as for setting vector length via prctl(). Ditto. [...] Cheers ---Dave _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel