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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 388B5C433DF for ; Fri, 5 Jun 2020 10:37:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0DA592075B for ; Fri, 5 Jun 2020 10:37:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726666AbgFEKhR (ORCPT ); Fri, 5 Jun 2020 06:37:17 -0400 Received: from foss.arm.com ([217.140.110.172]:53410 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726465AbgFEKhR (ORCPT ); Fri, 5 Jun 2020 06:37:17 -0400 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 574262B; Fri, 5 Jun 2020 03:37:16 -0700 (PDT) Received: from C02TD0UTHF1T.local (unknown [10.57.11.98]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 880453F52E; Fri, 5 Jun 2020 03:37:08 -0700 (PDT) Date: Fri, 5 Jun 2020 11:37:05 +0100 From: Mark Rutland To: Wooyeon Kim Cc: Catalin Marinas , Will Deacon , hk92.kim@samsung.com, Wooki Min , Bhupesh Sharma , yb.song@samsung.com, yj.yim@samsung.com, Julien Grall , Vincenzo Frascino , Sanghoon Lee , jinsoo37.kim@samsung.com, hyewon.ryu@samsung.com, yhwan.joo@samsung.com, Anisse Astier , Marc Zyngier , dongww.kim@samsung.com, linux-arm-kernel@lists.infradead.org, jihun.kim@samsung.com, Dave Martin , Kees Cook , Suzuki K Poulose , Sudeep Holla , Kristina Martsenko , junik.lee@samsung.com, sgun.bae@samsung.com, Jeongtae Park , kgene.kim@samsung.com, Thomas Gleixner , Allison Randal , Steve Capper , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, James Morse , hyeyeon5.shim@samsung.com, dh.han@samsung.com Subject: Re: [PATCH] arm64: fpsimd: Added API to manage fpsimd state inside kernel Message-ID: <20200605103705.GD85498@C02TD0UTHF1T.local> References: <20200605073052.23044-1-wooy88.kim@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200605073052.23044-1-wooy88.kim@samsung.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(). Thanks, Mark.