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 X-Spam-Level: X-Spam-Status: No, score=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41341C56201 for ; Thu, 12 Nov 2020 17:44:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF07D21D91 for ; Thu, 12 Nov 2020 17:44:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="HP0lTaK4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726225AbgKLRoK (ORCPT ); Thu, 12 Nov 2020 12:44:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:53770 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726203AbgKLRoK (ORCPT ); Thu, 12 Nov 2020 12:44:10 -0500 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 37BE32085B; Thu, 12 Nov 2020 17:44:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605203049; bh=/pR8UR2R6ckpUNSbTCSRqdogqWJzZ+GGF6/wsi7mjD8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HP0lTaK4P6HqkZah6GUMcUBks4Qhd5C6DKsQg7gYR30EznrvOttBY11L0+Xzlq48Z M65EiBZVTBPa9YHKQbeeHzUPY+IbdYg4OFK2FfJX76TVzpaGUkAEIKbXbC2eEPThsL cXKQwM7ldsDth2m7hl/wTodf7IADaTk1Pl2nk358= Date: Thu, 12 Nov 2020 17:44:03 +0000 From: Will Deacon To: Qais Yousef Cc: Marc Zyngier , Catalin Marinas , linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Suren Baghdasaryan , kernel-team@android.com Subject: Re: [PATCH 2/6] arm64: Allow mismatched 32-bit EL0 support Message-ID: <20201112174403.GC20000@willie-the-truck> References: <20201106125425.u6qoswsjfskyxtoo@e107158-lin.cambridge.arm.com> <20201106130007.GA10605@willie-the-truck> <20201106144835.q363ezyse4vc5kdg@e107158-lin.cambridge.arm.com> <20201109135259.GA14526@willie-the-truck> <20201111162700.p4sem2fup5qjjbqz@e107158-lin.cambridge.arm.com> <20201112102424.GB19506@willie-the-truck> <20201112115555.65sfsod6uf6xm5gy@e107158-lin.cambridge.arm.com> <20201112164943.7kdskvxcnuodphow@e107158-lin.cambridge.arm.com> <901a3fe0c600d81d6097fe31b0b9b02b@kernel.org> <20201112173645.7jdq3gtwisiryscd@e107158-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201112173645.7jdq3gtwisiryscd@e107158-lin.cambridge.arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Thu, Nov 12, 2020 at 05:36:45PM +0000, Qais Yousef wrote: > On 11/12/20 17:06, Marc Zyngier wrote: > > On 2020-11-12 16:49, Qais Yousef wrote: > > > On 11/12/20 11:55, Qais Yousef wrote: > > > > On 11/12/20 10:24, Will Deacon wrote: > > > > > On Wed, Nov 11, 2020 at 04:27:00PM +0000, Qais Yousef wrote: > > > > > > On 11/09/20 13:52, Will Deacon wrote: > > > > > > > On Fri, Nov 06, 2020 at 02:48:35PM +0000, Qais Yousef wrote: > > > > > > > > On 11/06/20 13:00, Will Deacon wrote: > > > > > > > > > On Fri, Nov 06, 2020 at 12:54:25PM +0000, Qais Yousef wrote: > > > > > > > > > > FWIW I have my v3 over here in case it's of any help. It solves the problem of > > > > > > > > > > HWCAP discovery when late AArch32 CPU is booted by populating boot_cpu_date > > > > > > > > > > with 32bit features then. > > > > > > > > > > > > > > > > > > > > git clone https://git.gitlab.arm.com/linux-arm/linux-qy.git -b asym-aarch32-upstream-v3 origin/asym-aarch32-upstream-v3 > > > > > > > > > > > > > > > > > > Cheers, I've done something similar. I was hoping to post it today, but I've > > > > > > > > > been side-tracked with bug fixing this morning. The main headache I ended up > > > > > > > > > with was allowing late-onlining of 64-bit-only CPUs if all the boot CPUs > > > > > > > > > are 32-bit capable. What do you do in that case? > > > > > > > > > > > > > > > > Do you mean if CPUs 0-3 were 32bit capable and we boot with maxcpus=4 then > > > > > > > > attempt to bring the remaining 64bit-only cpus online later? > > > > > > > > > > > > > > Right. I think we will refuse to online them. I'll post my attempt at > > > > > > > handling that shortly. > > > > > > > > > > > > Sorry for the delayed response. > > > > > > > > > > > > You're right, I tried that and they refuse to come online. We missed that tbh. > > > > > > > > > > > > Haven't thought what we should do yet. I tried your v2 and it failed similarly. > > > > > > > > > > Hmm, it shouldn't do. Please could you provide the log? My hunch is that you > > > > > are blatting 32-bit EL1 support as well, and we can't handle a mismatch for > > > > > that with a late CPU. Do you know if the CPUs being integrated into these > > > > > broken designs have a mismatch at EL1 as well? > > > > > > > > Hmm my test could have been invalid then. We shouldn't have mismatch > > > > at EL1, > > > > for ease of testing I used a hacked up patch to fake asymmetry on > > > > Juno. Testing > > > > on FVP now, it takes time to boot up though.. > > > > > > > > Let me re-run this and get you the log from proper environment. > > > > Assuming it > > > > still fails. > > > > > > Still fails the same on FVP. dmesg attached. There's a splat shortly > > > after > > > attempting to online CPU 4. > > > > > > # cat /sys/devices/system/cpu/online > > > 0-3 > > > # cat /sys/devices/system/cpu/aarch32_el0 > > > 0-3 > > > > > > Now while writing this I just realized I tell the FVP to disable aarch32 > > > support at EL0. So this might still make the kernel thinks there's > > > AArch32 > > > support at EL1 - which seems is what makes your series get confused? > > > > You can't have AArch32 at EL1 and not have it at EL0. > > > > > Anyway. No real hardware to test on and not sure if I can tell the FVP > > > to > > > disable AArch32 support at EL1. > > > > > > /me goes and dig > > > > -C cluster0.max_32bit_el=-1 # no 32bit support whatsoever > > -C cluster1.max_32bit_el=0 # 32bit support at EL0 only > > Ah okay. That's the option I use. I must have misinterpreted Will's words then > 'blatting 32-bit EL1'. Blame my English :-) I don't think "blatting" is a word, so I'm entirely to blame here! Will 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 X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71737C5519F for ; Thu, 12 Nov 2020 17:45:35 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E14FB2085B for ; Thu, 12 Nov 2020 17:45:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="kwlhBVgm"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="HP0lTaK4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E14FB2085B Authentication-Results: mail.kernel.org; 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Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kdGdq-0001XX-7u; Thu, 12 Nov 2020 17:44:14 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kdGdm-0001Wm-OQ for linux-arm-kernel@lists.infradead.org; Thu, 12 Nov 2020 17:44:12 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 37BE32085B; Thu, 12 Nov 2020 17:44:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605203049; bh=/pR8UR2R6ckpUNSbTCSRqdogqWJzZ+GGF6/wsi7mjD8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HP0lTaK4P6HqkZah6GUMcUBks4Qhd5C6DKsQg7gYR30EznrvOttBY11L0+Xzlq48Z M65EiBZVTBPa9YHKQbeeHzUPY+IbdYg4OFK2FfJX76TVzpaGUkAEIKbXbC2eEPThsL cXKQwM7ldsDth2m7hl/wTodf7IADaTk1Pl2nk358= Date: Thu, 12 Nov 2020 17:44:03 +0000 From: Will Deacon To: Qais Yousef Subject: Re: [PATCH 2/6] arm64: Allow mismatched 32-bit EL0 support Message-ID: <20201112174403.GC20000@willie-the-truck> References: <20201106125425.u6qoswsjfskyxtoo@e107158-lin.cambridge.arm.com> <20201106130007.GA10605@willie-the-truck> <20201106144835.q363ezyse4vc5kdg@e107158-lin.cambridge.arm.com> <20201109135259.GA14526@willie-the-truck> <20201111162700.p4sem2fup5qjjbqz@e107158-lin.cambridge.arm.com> <20201112102424.GB19506@willie-the-truck> <20201112115555.65sfsod6uf6xm5gy@e107158-lin.cambridge.arm.com> <20201112164943.7kdskvxcnuodphow@e107158-lin.cambridge.arm.com> <901a3fe0c600d81d6097fe31b0b9b02b@kernel.org> <20201112173645.7jdq3gtwisiryscd@e107158-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201112173645.7jdq3gtwisiryscd@e107158-lin.cambridge.arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201112_124411_048594_7EB2E762 X-CRM114-Status: GOOD ( 34.97 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, kernel-team@android.com, Catalin Marinas , Peter Zijlstra , Marc Zyngier , Greg Kroah-Hartman , Suren Baghdasaryan , Morten Rasmussen , linux-arm-kernel@lists.infradead.org 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 Thu, Nov 12, 2020 at 05:36:45PM +0000, Qais Yousef wrote: > On 11/12/20 17:06, Marc Zyngier wrote: > > On 2020-11-12 16:49, Qais Yousef wrote: > > > On 11/12/20 11:55, Qais Yousef wrote: > > > > On 11/12/20 10:24, Will Deacon wrote: > > > > > On Wed, Nov 11, 2020 at 04:27:00PM +0000, Qais Yousef wrote: > > > > > > On 11/09/20 13:52, Will Deacon wrote: > > > > > > > On Fri, Nov 06, 2020 at 02:48:35PM +0000, Qais Yousef wrote: > > > > > > > > On 11/06/20 13:00, Will Deacon wrote: > > > > > > > > > On Fri, Nov 06, 2020 at 12:54:25PM +0000, Qais Yousef wrote: > > > > > > > > > > FWIW I have my v3 over here in case it's of any help. It solves the problem of > > > > > > > > > > HWCAP discovery when late AArch32 CPU is booted by populating boot_cpu_date > > > > > > > > > > with 32bit features then. > > > > > > > > > > > > > > > > > > > > git clone https://git.gitlab.arm.com/linux-arm/linux-qy.git -b asym-aarch32-upstream-v3 origin/asym-aarch32-upstream-v3 > > > > > > > > > > > > > > > > > > Cheers, I've done something similar. I was hoping to post it today, but I've > > > > > > > > > been side-tracked with bug fixing this morning. The main headache I ended up > > > > > > > > > with was allowing late-onlining of 64-bit-only CPUs if all the boot CPUs > > > > > > > > > are 32-bit capable. What do you do in that case? > > > > > > > > > > > > > > > > Do you mean if CPUs 0-3 were 32bit capable and we boot with maxcpus=4 then > > > > > > > > attempt to bring the remaining 64bit-only cpus online later? > > > > > > > > > > > > > > Right. I think we will refuse to online them. I'll post my attempt at > > > > > > > handling that shortly. > > > > > > > > > > > > Sorry for the delayed response. > > > > > > > > > > > > You're right, I tried that and they refuse to come online. We missed that tbh. > > > > > > > > > > > > Haven't thought what we should do yet. I tried your v2 and it failed similarly. > > > > > > > > > > Hmm, it shouldn't do. Please could you provide the log? My hunch is that you > > > > > are blatting 32-bit EL1 support as well, and we can't handle a mismatch for > > > > > that with a late CPU. Do you know if the CPUs being integrated into these > > > > > broken designs have a mismatch at EL1 as well? > > > > > > > > Hmm my test could have been invalid then. We shouldn't have mismatch > > > > at EL1, > > > > for ease of testing I used a hacked up patch to fake asymmetry on > > > > Juno. Testing > > > > on FVP now, it takes time to boot up though.. > > > > > > > > Let me re-run this and get you the log from proper environment. > > > > Assuming it > > > > still fails. > > > > > > Still fails the same on FVP. dmesg attached. There's a splat shortly > > > after > > > attempting to online CPU 4. > > > > > > # cat /sys/devices/system/cpu/online > > > 0-3 > > > # cat /sys/devices/system/cpu/aarch32_el0 > > > 0-3 > > > > > > Now while writing this I just realized I tell the FVP to disable aarch32 > > > support at EL0. So this might still make the kernel thinks there's > > > AArch32 > > > support at EL1 - which seems is what makes your series get confused? > > > > You can't have AArch32 at EL1 and not have it at EL0. > > > > > Anyway. No real hardware to test on and not sure if I can tell the FVP > > > to > > > disable AArch32 support at EL1. > > > > > > /me goes and dig > > > > -C cluster0.max_32bit_el=-1 # no 32bit support whatsoever > > -C cluster1.max_32bit_el=0 # 32bit support at EL0 only > > Ah okay. That's the option I use. I must have misinterpreted Will's words then > 'blatting 32-bit EL1'. Blame my English :-) I don't think "blatting" is a word, so I'm entirely to blame here! Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel