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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 14C0CC04A6B for ; Mon, 13 May 2019 00:53:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0F69208C0 for ; Mon, 13 May 2019 00:53:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727260AbfEMAvT (ORCPT ); Sun, 12 May 2019 20:51:19 -0400 Received: from git.icu ([163.172.180.134]:53824 "EHLO git.icu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727054AbfEMAvT (ORCPT ); Sun, 12 May 2019 20:51:19 -0400 Received: from localhost.localdomain (minicloud.parqtec.unicamp.br [143.106.167.126]) by git.icu (Postfix) with ESMTPSA id 5583D220850; Mon, 13 May 2019 00:51:15 +0000 (UTC) From: Shawn Landden To: linuxppc-dev@lists.ozlabs.org Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , linux-kernel@vger.kernel.org, Shawn Landden Subject: [PATCH RESEND] powerpc: add simd.h implementation specific to PowerPC Date: Sun, 12 May 2019 21:51:04 -0300 Message-Id: <20190513005104.20140-1-shawn@git.icu> X-Mailer: git-send-email 2.21.0.1020.gf2820cf01a In-Reply-To: <20190512165032.19942-1-shawn@git.icu> References: <20190512165032.19942-1-shawn@git.icu> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is safe to do SIMD in an interrupt on PowerPC. Only disable when there is no SIMD available (and this is a static branch). Tested and works with the WireGuard (Zinc) patch I wrote that needs this. Also improves performance of the crypto subsystem that checks this. Re-sending because this linuxppc-dev didn't seem to accept it. Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=203571 Signed-off-by: Shawn Landden --- arch/powerpc/include/asm/simd.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 arch/powerpc/include/asm/simd.h diff --git a/arch/powerpc/include/asm/simd.h b/arch/powerpc/include/asm/simd.h new file mode 100644 index 000000000..b3fecb95a --- /dev/null +++ b/arch/powerpc/include/asm/simd.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ + +#include + +/* + * may_use_simd - whether it is allowable at this time to issue SIMD + * instructions or access the SIMD register file + * + * As documented in Chapter 6.2.1 Machine Status Save/Restore Registers + * of Power ISA (2.07 and 3.0), all registers are saved/restored in an interrupt. + */ +static inline bool may_use_simd(void) +{ + return !cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE); +} -- 2.21.0.1020.gf2820cf01a