From mboxrd@z Thu Jan 1 00:00:00 1970 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 BBEFFC433F5 for ; Wed, 2 Mar 2022 13:59:46 +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:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=WQRsejimLix1JYQJyoOzRnYe54CjAXSi/7S9CL5jTlg=; b=DuyeFScBmgpmTi 00Tob+WtDp1AvHu4KNyIfqO9b+nKvw1WqTYiNCQigNuVRF/jXMm8mmb1hopfkXfKzzjHAKlITN6UY Nf2oho3DsmtY48gcoLydHIcMR/ImD0OTZXGq/EsKmvQ08l7w0Ri771gyh1VJcVFWkrn3rjAjWpuBy WxUkPBKYeEI/cSO5CwGi/xl17cqPMsLMYaD6oqyLax5v+aSNSLu/iFO9auJA46pFOsipC8pZUmYZz h3y+etW4KZAOeUXXgsw1KxXlj3RJ/Z9EU1sWD11B1ACu2dffxVfdXMP4Ok5hHSN2SsqODRB2ndSfh yOhVCJWO7lThRzPgrazA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nPPUo-002twc-37; Wed, 02 Mar 2022 13:58:26 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nPPUi-002tw1-J3 for linux-arm-kernel@lists.infradead.org; Wed, 02 Mar 2022 13:58:22 +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 ams.source.kernel.org (Postfix) with ESMTPS id 47ACFB81F16; Wed, 2 Mar 2022 13:58:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1252FC004E1; Wed, 2 Mar 2022 13:58:16 +0000 (UTC) Date: Wed, 2 Mar 2022 13:58:13 +0000 From: Catalin Marinas To: Mark Brown Cc: Will Deacon , linux-arm-kernel@lists.infradead.org, Mark Rutland Subject: Re: [PATCH] arm64: Don't allow SVE to be used with BROKEN_GAS_INST Message-ID: References: <20220225184045.5502-1-broonie@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220225184045.5502-1-broonie@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220302_055820_795401_1C518F19 X-CRM114-Status: GOOD ( 23.99 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Feb 25, 2022 at 06:40:45PM +0000, Mark Brown wrote: > We support building the kernel with archaic versions of binutils which > had some confusion regarding how instructions should be encoded for .inst > which we work around with the __emit_inst() macro. Unfortunately we have > not consistently used this macro, one of the places where it's missed being > the macros that manually encode SVE instructions. This means that kernels > built with such toolchains have never supported SVE correctly. > > Since these toolchains are very old (some idle research suggested 2015 > era) it seems more sensible to just refuse to build SVE support with them, > in the unlikely event that someone has a need to use such a toolchain to > build a kernel which will run on a system with SVE support they can always > fix this properly but it seems more likely that we will deprecate support > for these toolchains and remove __emit_inst() before that happens. > > Signed-off-by: Mark Brown > --- > arch/arm64/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index f8e5f64fc40b..4312cc622277 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -1899,6 +1899,7 @@ endmenu > config ARM64_SVE > bool "ARM Scalable Vector Extension support" > default y > + depends on !BROKEN_GAS_INST It looks like it's not just SVE affected here. A grep for "\.inst\>" shows a few places in the crypto code as well. How hard is it to use __emit_inst() in these places? -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel