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=-7.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,PDS_BAD_THREAD_QP_64,SPF_HELO_NONE,SPF_PASS 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 735BAC433B4 for ; Mon, 26 Apr 2021 13:14:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 38D1661103 for ; Mon, 26 Apr 2021 13:14:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233376AbhDZNPE (ORCPT ); Mon, 26 Apr 2021 09:15:04 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:22669 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231862AbhDZNPE (ORCPT ); Mon, 26 Apr 2021 09:15:04 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1619442862; h=Content-Transfer-Encoding: Content-Type: MIME-Version: Message-ID: Date: Subject: In-Reply-To: References: Cc: To: From: Reply-To: Sender; bh=2aasOBDfVeKKukuy1LhKC7ZOGD0SUDLdz1bz/6bTWp8=; b=A7DLCagvQEglF19UICEKrEU0PTtM5p0WrtH5/lvh33Oszp0F5GKAag1qpe7PxNQx512XLdWV KFUwo68wuWlDnuVwt1utXXZN4MOmWNq/Gz/mmOTn8BxLPlfKdadO3qRCcrbkFSosX9WEEEP4 xXeSUFbltt1KoWkGXSbfcFi+Y/M= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyI5MDNlZiIsICJsaW51eC1hcmNoQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n05.prod.us-east-1.postgun.com with SMTP id 6086bc8aa817abd39acb10d5 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 26 Apr 2021 13:13:46 GMT Sender: bcain=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id E4283C4338A; Mon, 26 Apr 2021 13:13:45 +0000 (UTC) Received: from BCAIN (104-54-226-75.lightspeed.austtx.sbcglobal.net [104.54.226.75]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bcain) by smtp.codeaurora.org (Postfix) with ESMTPSA id 40E3FC433D3; Mon, 26 Apr 2021 13:13:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 40E3FC433D3 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=bcain@codeaurora.org Reply-To: From: "Brian Cain" To: "'Nick Desaulniers'" Cc: "'Arnd Bergmann'" , "'open list:QUALCOMM HEXAGON...'" , "'clang-built-linux'" , "'linux-arch'" , "'Guenter Roeck'" , "'Randy Dunlap'" , "'Miguel Ojeda'" References: <025b01d7386f$78deed80$6a9cc880$@codeaurora.org> In-Reply-To: Subject: RE: ARCH=hexagon unsupported? Date: Mon, 26 Apr 2021 08:13:43 -0500 Message-ID: <034f01d73a9d$fc4ed420$f4ec7c60$@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Mailer: Microsoft Outlook 16.0 Content-Language: en-us Thread-Index: AQHA6GaHPKlqiI34kZpdCyOyqmKBQAItWAQVAr2ClWoDAPOEXKq0DBKw Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org > -----Original Message----- > From: Nick Desaulniers > Sent: Friday, April 23, 2021 4:40 PM > To: Brian Cain > Cc: Arnd Bergmann ; open list:QUALCOMM HEXAGON... > ; clang-built-linux linux@googlegroups.com>; linux-arch ; = Guenter > Roeck ; Randy Dunlap ; = Miguel > Ojeda > Subject: Re: ARCH=3Dhexagon unsupported? >=20 > On Fri, Apr 23, 2021 at 11:35 AM Brian Cain = wrote: > > > > > -----Original Message----- > > > From: Arnd Bergmann > > > Sent: Friday, April 23, 2021 4:37 AM > > > To: Nick Desaulniers > > > Cc: open list:QUALCOMM HEXAGON... ; > > > clang-built-linux ; Brian Cain > > > ; linux-arch ; > > > Guenter Roeck > > > Subject: Re: ARCH=3Dhexagon unsupported? > > > > > > On Fri, Apr 23, 2021 at 12:12 AM 'Nick Desaulniers' via Clang = Built > > > Linux wrote: > > > > > > > > Arnd, > > > > No one can build ARCH=3Dhexagon and > > > > https://github.com/ClangBuiltLinux/linux/issues/759 has been = open > > > > for > > > > 2 years. > > > > > > > > Trying to build > > > > $ ARCH=3Dhexagon CROSS_COMPILE=3Dhexagon-linux-gnu make LLVM=3D1 > > > LLVM_IAS=3D1 > > > > -j71 > > > > > > > > shows numerous issues, the latest of which commit 8320514c91bea > > > > ("hexagon: switch to ->regset_get()") has a very obvious typo > > > > which misspells the `struct` keyword and has been in the tree = for > > > > almost 1 year. > > > > > > Thank you for looking into it. > > > > > > > Why is arch/hexagon/ in the tree if no one can build it? > > > > > > Removing it sounds reasonable to me, it's been broken for too = long, > > > and we did the same thing for unicore32 that was in the same > > > situation where the gcc port was too old to build the kernel and = the > > > clang port never quite work in mainline. > > > > > > Guenter also brought up the issue a year ago, and nothing = happened. > > > I see Brian still occasionally sends an Ack to a patch that gets > > > merged through another tree, but he has not send any patches or = pull > > > requests himself after taking over maintainership from Richard Kuo > > > in 2019, and the four hexagon pull requests after 2014 only > > > contained build fixes from developers that don't have access to = the > > > hardware (Randy Dunlap, Viresh Kumar, Mike Frysinger and me). > > > > Nick, Arnd, > > > > I can appreciate your frustration, I can see that I have let the = community > down here. I would like to keep hexagon in-tree and I am committed to > making the changes necessary to do so. >=20 > I'm very happy to hear that. >=20 > > I have a patch under internal review to address the cited build = issues and > libgcc/compiler-rt content. >=20 > We'd be first in line to help build test such a patch. Please consider = cc'ing > myself and clang-built-linux@googlegroups.com when such a patch is > available externally. Further, we have the CI ready and waiting to = add new > architectures, even if it's just build testing. That would have caught > regressions like 8320514c91bea; we were down to 1 build failure with > https://github.com/ClangBuiltLinux/linux/issues/759 last I looked = which was > preventing us from adding Hexagon to any CI, but we must now dig = ourselves > out of a slightly deeper hole now. >=20 > Is this patch something you suspect will take quite some time to work = through > internal review? I don't think it should take long, no. I should have a better idea = today of about how long it will take. We will share it ASAP. > > In addition, my team has been focusing on developing QEMU system = mode > support that would mitigate some of the need for having hardware = access. > We have landed support for userspace hexagon-linux in upstream QEMU. >=20 > That's also great to hear. QEMU is a critical part of our CI for boot = testing; if > there's more info on timelines or what's involved with booting a = hexagon > kernel in QEMU, we'd be very happy to know how or when that's = available. >=20 > > My team and I want to make hexagon's open source footprint larger, = not > smaller. I realize that not being a good steward of the hexagon = kernel has not > helped, and we will do what we can to fix it. >=20 > A worthwhile and appreciated sentiment. I believe you. >=20 > Hexagon could be an interesting case for LLVM support in general for = the > Linux kernel; a case where each target or driver need not necessarily = have a > GCC backend to be acceptable. But barring anyone from being able to = actually > build it (let alone run it), it's not that; it's less than that. It's = dead code that bit > rots further and burdens maintainers who are maintaining something = that's > already broken. I'm not sure who derives any benefit. >=20 > I think it's in everyone's best interest to see Linux support more = targets than > fewer, and 2020 has been a hard year, but I'm curious how long = something > has to be broken before folks say "enough." Please let's support this = properly > or recognize the situation for what it is. I don't think the special circumstances of 2020 are to blame, it's just = my failure to give this work the priority it deserves. Agreed: we will = support the target properly. -Brian