From nobody Mon Feb 9 15:10:33 2026 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 8B3ADC7EE25 for ; Wed, 7 Jun 2023 20:43:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234592AbjFGUnI (ORCPT ); Wed, 7 Jun 2023 16:43:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234475AbjFGUm6 (ORCPT ); Wed, 7 Jun 2023 16:42:58 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BB9D2113 for ; Wed, 7 Jun 2023 13:42:36 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 284816463E for ; Wed, 7 Jun 2023 20:42:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D39AC433EF; Wed, 7 Jun 2023 20:42:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686170550; bh=5aQZkv7b76uNRIEEdQU8uQNP36af9VapveubHqYUaFQ=; h=From:Date:Subject:To:Cc:From; b=NOTgZAD9znY+E34eMdNxRrYZ9WFsjp1bDtbNZVPoEftzkVH/LzVi1T42kRaawir7c NKA/2AjGOyWhxbmJzrbHGjdA7pSvm7+lfpg16pLt9bsfH4AZkHLwo5+8JqlFNyuJRh 7HAjjVnt3E4qFM034doh6Aq/Qy6uqlO20o3YNdW2Q4qpoQj1twc3ZaivgDDRxB8WMW +JguAl1+rO+7mT7HLUowSatyk5ow8CegDMLYVnOnQNRGZZK8Fay5SM+68iaSYZhQHf MywLNQWEq6NYWrVPwT0VW65dcA5Z7zjIACREG6zVEGXlqw1NGRSoE2aaou8xtKX+tr AKotEd4N2Mqvg== From: Mark Brown Date: Wed, 07 Jun 2023 21:30:51 +0100 Subject: [PATCH] arm64/fpsimd: Exit streaming mode when flushing tasks MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20230607-arm64-flush-svcr-v1-1-7821a6199e0a@kernel.org> X-B4-Tracking: v=1; b=H4sIAPvogGQC/x2N0QrCMAwAf2Xk2UCdoxV/RXxIY2aD2kmCUxj7d zsf7+C4BVxMxeHULWAyq+tUG+x3HXChehPUa2PoQ38IMSQke8YBx8fbC/rMhkNiTpGOnDNDyzK 5YDaqXLbwM9l90y+TUb//0/myrj82jPm5eQAAAA== To: Catalin Marinas , Will Deacon Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Anders Roxell , Naresh Kamboju , Mark Brown X-Mailer: b4 0.13-dev-bfdf5 X-Developer-Signature: v=1; a=openpgp-sha256; l=1038; i=broonie@kernel.org; h=from:subject:message-id; bh=5aQZkv7b76uNRIEEdQU8uQNP36af9VapveubHqYUaFQ=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBkgOu0OWZtXqQLnmaga8qWcEKH43zY/MuFSc6R2FTB QHARcI6JATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZIDrtAAKCRAk1otyXVSH0F81B/ 0RF7RycQjSNI9WUnqO2R7nmzQwDLgtpGzQr5kXvGiRcOELDrerPK8ajLa+QDvaqgla82fv5d5Khccm b9iZhy0q9RE35vZlqXELzI1IQ1PVvL60gNaE42C3AXZndnQdoWxUN9PNoilPLdDP+W6tmE2tlxFgfy SW5+K61o5rJr8RlwuuOBIRGZb4BKWr0h0WEDOgml9yRh+q/jUaBQrW8iUa+e9OFqJKFdsQG6+GuUGi DFygUmJwPf08bJpxFYhKhMAAhEJHyeoK2+K8o+OOUpX1NjwbLBs/lU3QVZbpCxm7TmyOjIMh7JKUkX nvYQXSb30SRsVSaphjQPmpBN0BcDch X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ensure there is no path where we might attempt to save SME state after we flush a task by updating the SVCR register state as well as updating our in memory state. I haven't seen a specific case where this is happening or seen a path where it might happen but for the cost of a single low overhead instruction it seems sensible to close the potential gap. Signed-off-by: Mark Brown --- arch/arm64/kernel/fpsimd.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 2fbafa5cc7ac..1627e0efe39a 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1649,6 +1649,7 @@ void fpsimd_flush_thread(void) =20 fpsimd_flush_thread_vl(ARM64_VEC_SME); current->thread.svcr =3D 0; + sme_smstop_sm(); } =20 current->thread.fp_type =3D FP_STATE_FPSIMD; --- base-commit: 44c026a73be8038f03dbdeef028b642880cf1511 change-id: 20230607-arm64-flush-svcr-47cc76a8cbbc Best regards, --=20 Mark Brown