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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 99437C433DF for ; Mon, 8 Jun 2020 10:34:16 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 6781F2076A for ; Mon, 8 Jun 2020 10:34:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="RZkN0kcj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6781F2076A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject: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=1zhgV3X8vWSNuStUKDyTn8S1VOPoj4DF5dR26HcDI8s=; b=RZkN0kcj8OCn2f xI/JhQTA0VerUQpmbgoVQAyA+zLM7GTcVYCIXmOwQVRMyzSsH133HovIi9lOVS4sgjABWMiylx312 USurza8YKHcIpoe/nQuAdR+aAFFsW04f1RWZXY6XNTuGeZXsAUQcavjrQYlnI4+EyhE1d8cAm68h2 phlkCbjlOIUB5RcHIfa1OeitFUJSkdruFRwclGn9QFK8qIfVxN01BrHZxfhyJrWAeIOxKsHxQtvzp E6r7/X0zLSxmTVMEUfgUexfSA6qYquQ9+txGb52s4Y353JKdyFtS+xuc4xHihCYF5dUwXTuGVfshF avTatyz7ZpMTawpHWNjA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jiF6d-0001x9-Ks; Mon, 08 Jun 2020 10:34:15 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jiF6b-0001wg-2x for linux-arm-kernel@lists.infradead.org; Mon, 08 Jun 2020 10:34:14 +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 6C2E11FB; Mon, 8 Jun 2020 03:34:10 -0700 (PDT) Received: from arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BF0333F73D; Mon, 8 Jun 2020 03:34:05 -0700 (PDT) Date: Mon, 8 Jun 2020 11:34:00 +0100 From: Dave Martin To: Mark Rutland Subject: Re: [PATCH] arm64: fpsimd: Added API to manage fpsimd state inside kernel Message-ID: <20200608103340.GA31466@arm.com> References: <20200605073052.23044-1-wooy88.kim@samsung.com> <20200605103705.GD85498@C02TD0UTHF1T.local> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200605103705.GD85498@C02TD0UTHF1T.local> User-Agent: Mutt/1.5.23 (2014-03-12) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200608_033413_176029_5598B351 X-CRM114-Status: GOOD ( 19.78 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: hk92.kim@samsung.com, Catalin Marinas , Bhupesh Sharma , yb.song@samsung.com, yj.yim@samsung.com, Julien Grall , Vincenzo Frascino , Will Deacon , jinsoo37.kim@samsung.com, hyewon.ryu@samsung.com, yhwan.joo@samsung.com, Anisse Astier , Marc Zyngier , dongww.kim@samsung.com, Allison Randal , jihun.kim@samsung.com, Kees Cook , Suzuki K Poulose , Wooki Min , Wooyeon Kim , junik.lee@samsung.com, sgun.bae@samsung.com, Jeongtae Park , kgene.kim@samsung.com, Kristina Martsenko , Thomas Gleixner , Sanghoon Lee , linux-arm-kernel@lists.infradead.org, Sudeep Holla , Steve Capper , hyeyeon5.shim@samsung.com, linux-kernel@vger.kernel.org, James Morse , Greg Kroah-Hartman , dh.han@samsung.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Jun 05, 2020 at 11:37:05AM +0100, Mark Rutland wrote: > Hi Wooyeon, > > There are a *lot* of people Cc' here, many of whomo will find this > irrelevant. Please try to keep the Cc list constrained to a reasonable > number of interested parties. > > On Fri, Jun 05, 2020 at 04:30:52PM +0900, Wooyeon Kim wrote: > > From: Wooki Min > > > > This is an patch to use FPSIMD register in Kernel space. > > It need to manage to use FPSIMD register without damaging it > > of the user task. > > Following items have been implemented and added. > > Please introduce the problem you are trying to solve in more detail. We > already have kernel_neon_{begin,end}() for kernel-mode NEON; why is that > not sufficient for your needs? Please answer this before considering > other details. > > What do you want to use this for? > > > > > 1. Using FPSIMD in ISR (in_interrupt) > > It can used __efi_fpsimd_begin/__efi_fpsimd_end > > which is already implemented. > > Save fpsimd state before entering ISR, > > and restore fpsimd state after ISR ends. > > For use in external kernel module, > > it is declared as EXPORT_SYMBOL. > > This patch adds no in-tree modular users of this, so per the usual > conventions, NAK to EXPORT_SYMBOL(). Ack, this looks supicious. Can you explain why your usecase _requires_ FPSIMD in hardirq context? For now, these functions are strictly for EFI use only and should never be used by modules. Cheers ---Dave _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel