From patchwork Wed Nov 6 16:42:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 13865183 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 ED639D59F53 for ; Wed, 6 Nov 2024 16:45:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=/if1AiRZaUShOTuAFVIb1uest70Ah2Im5FIfKteFDIk=; b=TwfZKlx07T27MWBU6io6G7sBjU zRFPQBNOyN12UUUVfElRdvSzdsCk0v2uWyhE58Slxh6aX1cZRj6qFlxjfG6AzHfFpSIVQ3ul6p+W8 5+nmG172C19CpHb1XFwAAcZlNHhIDK+ouCSrGMZNllJYgXcJ4k5cvkSvsQFOrLBcoM/JGYR/K2IZi 1N0gfpmaujTyPMG0sHuzejxBGuPNfBQ007ak2/0nSngXGzBnOZxEJBzguVU4WioAAc8Qo57cIQhIc wc5PhOr6ES9sf4EbSopiyPV3wQCUhYOwWxw9DydqPwBQWEIW7Q7nJpEl8ddaUV3sGDUWIN5k5qI0L jG8cUTew==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t8j9W-000000044xJ-1fi8; Wed, 06 Nov 2024 16:45:06 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t8j75-000000044RP-0bjx for linux-arm-kernel@lists.infradead.org; Wed, 06 Nov 2024 16:42:36 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 87D131063; Wed, 6 Nov 2024 08:43:04 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 9F4673F528; Wed, 6 Nov 2024 08:42:33 -0800 (PST) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Cc: ardb@kernel.org, broonie@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, maz@kernel.org, stable@vger.kernel.org, will@kernel.org Subject: [PATCH] arm64: Kconfig: Make SME depend on BROKEN for now Date: Wed, 6 Nov 2024 16:42:20 +0000 Message-Id: <20241106164220.2789279-1-mark.rutland@arm.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241106_084235_245105_2FBFCC3D X-CRM114-Status: GOOD ( 11.36 ) 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 Although support for SME was merged in v5.19, we've since uncovered a number of issues with the implementation, including issues which might corrupt the FPSIMD/SVE/SME state of arbitrary tasks. While there are patches to address some of these issues, ongoing review has highlighted additional functional problems, and more time is necessary to analyse and fix these. For now, mark SME as BROKEN in the hope that we can fix things properly in the near future. As SME is an OPTIONAL part of ARMv9.2+, and there is very little extant hardware, this should not adversely affect the vast majority of users. Signed-off-by: Mark Rutland Cc: Ard Biesheuvel Cc: Catalin Marinas Cc: Marc Zyngier Cc: Mark Brown Cc: Will Deacon Cc: # 5.19 Acked-by: Catalin Marinas --- arch/arm64/Kconfig | 1 + 1 file changed, 1 insertion(+) Catalin, Will, if we take this, the minimal set of other fixes necessary for now is: * "arm64/sve: Discard stale CPU state when handling SVE traps" https://lore.kernel.org/linux-arm-kernel/20241030-arm64-fpsimd-foreign-flush-v1-1-bd7bd66905a2@kernel.org/ https://lore.kernel.org/linux-arm-kernel/ZypuQNhWHKut8mLl@J2N7QTR9R3.cambridge.arm.com/ (already queued by Will in for-next/fixes) * "arm64: smccc: Remove broken support for SMCCCv1.3 SVE discard hint" https://lore.kernel.org/linux-arm-kernel/20241106160448.2712997-1-mark.rutland@arm.com/ Mark. diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 3e29b44d2d7bd..14cc81e154ee2 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2213,6 +2213,7 @@ config ARM64_SME bool "ARM Scalable Matrix Extension support" default y depends on ARM64_SVE + depends on BROKEN help The Scalable Matrix Extension (SME) is an extension to the AArch64 execution state which utilises a substantial subset of the SVE