From patchwork Tue Apr 19 11:22:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 564618 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 E3B5BC433F5 for ; Tue, 19 Apr 2022 11:25:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349965AbiDSL2Q (ORCPT ); Tue, 19 Apr 2022 07:28:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351353AbiDSL1m (ORCPT ); Tue, 19 Apr 2022 07:27:42 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9240712ABE for ; Tue, 19 Apr 2022 04:25:00 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 44592B81846 for ; Tue, 19 Apr 2022 11:24:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 59E9FC385A5; Tue, 19 Apr 2022 11:24:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1650367497; bh=hKEqxVq3qIYNyJ3Q5Mx9hTOo2XjAx/mVC4NFmLZ1diw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OtdXNzNGNqIEpXHSfEQAcoqLQA0OwnOcKDqUUOsEK30/CwM/vmZM55bFDdRdVgate FIqnXzaLYHO6Uh/guVYztKPCO4PoqTKx2JhLdMpBbS6Z1tLMM0hbc3QuItEsnaseMe idZi3Dogm7SVDh0YiZO3vJoAm/SXLVXOmusumws0EHuPEYhE4R4sMl4b/iGu8eAo5P MJs8hrCwE4uSP4+NNdguB3ju4hmOmvFdK+gTlOqPq//zvOFbIFS0wxW/GmN+CXD7Vz shVizrxaqmq6xGDR0qxFzz78MiqeGSTYCUEE+jaE6SaR0mBG7h5gF5iCU4zwMAeIfA ultWbR4Ehl4tg== 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 , Luca Salabrino , linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, kvmarm@lists.cs.columbia.edu, Mark Brown Subject: [PATCH v14 22/39] arm64/sme: Disable streaming mode and ZA when flushing CPU state Date: Tue, 19 Apr 2022 12:22:30 +0100 Message-Id: <20220419112247.711548-23-broonie@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220419112247.711548-1-broonie@kernel.org> References: <20220419112247.711548-1-broonie@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1184; h=from:subject; bh=hKEqxVq3qIYNyJ3Q5Mx9hTOo2XjAx/mVC4NFmLZ1diw=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBiXpt5bayPRAObOqjq+ZBzKh1FKgvLLGsBQ3TgiJDo PC1NiqOJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCYl6beQAKCRAk1otyXVSH0HsjB/ 99t6AWS0KoiDaWwA1DqLBTFqSSLoaO0NK6a/uwv+HSzr8GMop4VZ4Jx+wxMhIFhR3ZQTNnGhdadvR+ 33Ozd+ypw9AO57hbRuNZX1/Vt9Au6jm3irZzve/q5nrjy86I4wnyl114GsOwjTUaB+g2Zn2tSPoDLo 2YuS73oV0vFDm3aTswWCgxcF+SA10fDBiIotXrR8ADPZA2DotX58GxC19jFaNdhHC7qLzbNw+biCAu RiUjOMub4MO3jeWg+ooKKn6TWhVv8tg5k7G5GlwDpO1sVhoErSG6LXOq7ZR/90i/ZVPSZCewptyPfy Xl3RcId+7mqhbe5HN2xu31t7cvmNnF 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 Reviewed-by: Catalin Marinas --- 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 94f06e9d37cf..9592cdd7d635 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1759,6 +1759,15 @@ 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); }