From patchwork Fri Jun 9 22:43:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13274612 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E0EEAC7EE25 for ; Fri, 9 Jun 2023 22:44:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Message-Id:MIME-Version:Subject: Date:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=Cjdv4pR1k21s5ip/PWof/BB0Vur0dUIiIvmRDIaChzQ=; b=fHggx49hsBwpBG NOuKI7PixdMXR8MWboNaXNWgln+kDBOADOxGZNPjD2Qws1y1NvPCDa1OjXBJSuFP8h9s3ftfF9QF8 Do1XK6b1Ujq94cjoO4VEZ9aCsU4ga/ROdyIb3flifG6TdyP7/LPkp0BTNqaPX4Qmd9cLAWKUAoyl3 iQTv+PwbQfh4SJpEmN2KYR6tgc+cEhSd9MWXrVgvvE3RpDeQ0Cq1hBRYQuW/yUC8YlBiAVS7JkoYg LLx5J9kKAuE0vkL8B8LTCxT2FDTwlwiTObP9B7dDua9LzxKaKNWzpc0+X/cXUhQDSL3U//WcF9uCZ w8wXMghHi4UnBkhDqpDg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q7kpo-00ESMW-1N; Fri, 09 Jun 2023 22:43:56 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1q7kpl-00ESLq-1d for linux-arm-kernel@lists.infradead.org; Fri, 09 Jun 2023 22:43:54 +0000 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 D062161AC8; Fri, 9 Jun 2023 22:43:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C060CC433EF; Fri, 9 Jun 2023 22:43:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686350632; bh=pFXxi/+k0vgMNVbo/aKTzxMO8ok6BkKhrmW5ZW5j7JE=; h=From:Date:Subject:To:Cc:From; b=Um6tyhVDVM1tBkhRxlYN3csYLcMYhwLbZYn+iQ5SUOEptjd2UUFzM/uY1NmTRJHgJ WO8ommVW0albmjJPqdXnzDCP2yNWJ5f7b3G4OXLUoizF+JGETrIJ2Q3CrZ0SXS3pYI TRt0h2nXOX+uprOG8gIs+zqnLAemelRr1YsjfLeUCRJbwhY4jceYpuhDZdTCmJbtHl IgdNVEfCcsN4hvPLRo8diIzhFADpzUqclgKlJw/SWTI90E6BnvbDrYVhmovtCc6vxO 3r0VaPZLZKo3DEQs5yy9GuozF6rJqLK9l0T2IXFAZ5zx3wOEk3eXbgae+CQL4ufVZz SmnpYTy/4EozA== From: Mark Brown Date: Fri, 09 Jun 2023 23:43:41 +0100 Subject: [PATCH v2] arm64/fpsimd: Exit streaming mode when flushing tasks MIME-Version: 1.0 Message-Id: <20230607-arm64-flush-svcr-v2-1-827306001841@kernel.org> X-B4-Tracking: v=1; b=H4sIAByrg2QC/32NQQ7CIBAAv9Jwdg1gQ1tP/sP0ALgtpBXMoqhp+ ndpH+BxJpnMwhKSx8TO1cIIs08+hgLyUDHrdBgR/K0wk1yeuOINaLqrGob5lRykbAnqxtpG6dY aY1nJjE4IhnSwbgvfkaZNPwgH/9lP176w8+kZ6buPs9jsn0cWIKBppdBKdB1yfZmQAs7HSCPr1 3X9AYVnDo/IAAAA 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=1193; i=broonie@kernel.org; h=from:subject:message-id; bh=pFXxi/+k0vgMNVbo/aKTzxMO8ok6BkKhrmW5ZW5j7JE=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBkg6sl7hwnoCTpgzs8tkHwo1tsLhOytwBi8AEz9daW wkZDurmJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZIOrJQAKCRAk1otyXVSH0EfMB/ 4iqKhRm1wjF7Flf4wvqcjNAsKMrWOvwFpKn3Lrf+4Bnw4/p3udF9Gl/+wf1UjPsnl/L41AjgkzW/23 cga9vRpCvRnQUYLzc61LYJSOmlNKCTUgcRV/8yZjxxsqj3ExOrQqTF2FpQUcBiY4Dk4v7RqFnnQdF3 19VLxC5QgFeOGysFPDaPN6MMuk4HMCLpbdtz7K5SBF9eLLhY9C/hTbGMHvml/l50VQZL5iYypbRtcZ YeQ+HkZTIa2U3HeWheolO1FvUOgNzxc5GkvytsYdAatWZkL5aYy3fTuyAOZTF9cTNg8kYOhfQsAq+o VV61IbAAB/7AYYE+lUorxFwRWlpW+r X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230609_154353_582354_5129EDCB X-CRM114-Status: GOOD ( 12.32 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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 --- Changes in v2: - Do a full SMSTOP to cover ZA as well. - Link to v1: https://lore.kernel.org/r/20230607-arm64-flush-svcr-v1-1-7821a6199e0a@kernel.org --- arch/arm64/kernel/fpsimd.c | 1 + 1 file changed, 1 insertion(+) --- base-commit: 44c026a73be8038f03dbdeef028b642880cf1511 change-id: 20230607-arm64-flush-svcr-47cc76a8cbbc Best regards, diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 2fbafa5cc7ac..7a1aeb95d7c3 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1649,6 +1649,7 @@ void fpsimd_flush_thread(void) fpsimd_flush_thread_vl(ARM64_VEC_SME); current->thread.svcr = 0; + sme_smstop(); } current->thread.fp_type = FP_STATE_FPSIMD;