From patchwork Tue Jan 25 00:10:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 12723041 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D3EEC46467 for ; Tue, 25 Jan 2022 00:30:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S3409228AbiAYAZM (ORCPT ); Mon, 24 Jan 2022 19:25:12 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:52114 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2374324AbiAYAQt (ORCPT ); Mon, 24 Jan 2022 19:16:49 -0500 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 dfw.source.kernel.org (Postfix) with ESMTPS id A68B061543 for ; Tue, 25 Jan 2022 00:16:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B056BC340E9; Tue, 25 Jan 2022 00:16:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643069808; bh=+stvVyRnz2H4xbnaEtKWfcp0/IPDCeyODbC6Y5cXcCY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C8wbOYozrg4+ovKqrWnHq18dFa0bz71bu8Rr/6/ewc58V43gHblWYO25/Zn7FB57v xubMD6JJHVgn3VvtrRhwWg7zvLqw5dTL59NWQFEPCmonHw7qSJ8H2nwPcq2a2KGu5w CXTMeCc17fNBNw/eYs3h4OUF6Q3Q72n5DthiAl5E6wO9X07Ix4gq3THDXmbp8gsLzM 3Wb6/eEdOUCOWqrN6eIVsP3hZdmqN/8xgofETXtVellDBvX+nWqhlGVplYyFH3WvBf zmSMQUnpSUvUUK8rMwLkWi+UG0ZrDhn6Z3u6RYH3JlbhPYZ4DCjxKG3qW2bF9ptIw4 aeVPuNh3Xy0Xw== From: Mark Brown To: Catalin Marinas , Will Deacon , Marc Zyngier , Shuah Khan , Shuah Khan Cc: 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, Mark Brown Subject: [PATCH v8 22/38] arm64/sme: Disable streaming mode and ZA when flushing CPU state Date: Tue, 25 Jan 2022 00:10:58 +0000 Message-Id: <20220125001114.193425-23-broonie@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220125001114.193425-1-broonie@kernel.org> References: <20220125001114.193425-1-broonie@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1128; h=from:subject; bh=+stvVyRnz2H4xbnaEtKWfcp0/IPDCeyODbC6Y5cXcCY=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBh70ASZjkrllyw3wrZv65gkzLMq7K6hvi8wR5NerZM dVGlefyJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCYe9AEgAKCRAk1otyXVSH0NbyB/ 0aSvLUKYmoq6mFoAyvpGc/oT3Cs8OYVjbNPgjDw2ExcuHRbslUM2Mr0KL3jFfhvee4XeVMl6fVdWZI qr658iRh7kGFTUU5UE1J2hqhfohsDh8EC7a2+S+ZtcAe/r/ZiuJcqDkykG2UFXWHj1npykI9B0/ybx q1KkfrLoGwkFQq8Qtgl3b93K1iOrmi8x76b7aRvmIWQIwDoEXTF5GOuSpRACciWM4n1Y4cn6X9s71n RmgmsUeY+jswAhlV+8Yk5JRxyHjS+ibi0+kDGF0PbS1KpMhTa0+3R6w0ZrX3XP1IuU63+JgCi2qfNe 7JzsueypROn3Znfz+GdLab96n/x3mG X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Both streaming mode and ZA may increase power consumption when they are enabled and streaming mode makes many FPSIMD and SVE instructions undefined which will cause problems for any kernel mode floating point so disable both when we flush the CPU state. This covers both kernel_neon_begin() and idle and after flushing the state a reload is always required anyway. Signed-off-by: Mark Brown --- arch/arm64/kernel/fpsimd.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 8b111b7f2006..e00d3a9e919c 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1762,6 +1762,15 @@ static void fpsimd_flush_cpu_state(void) { WARN_ON(!system_supports_fpsimd()); __this_cpu_write(fpsimd_last_state.st, NULL); + + /* + * Leaving streaming mode enabled will cause issues for any kernel + * NEON and leaving streaming mode or ZA enabled may increase power + * consumption. + */ + if (system_supports_sme()) + sme_smstop(); + set_thread_flag(TIF_FOREIGN_FPSTATE); }