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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 665DFC4CEC4 for ; Thu, 19 Sep 2019 13:37:15 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 2D5B221D56 for ; Thu, 19 Sep 2019 13:37:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="mwBzoNaT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2D5B221D56 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 02EBECC4; Thu, 19 Sep 2019 13:37:15 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 6B442504 for ; Thu, 19 Sep 2019 13:37:13 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 46AF583A for ; Thu, 19 Sep 2019 13:37:12 +0000 (UTC) Received: from mail-wr1-f41.google.com (mail-wr1-f41.google.com [209.85.221.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C2409222BF for ; Thu, 19 Sep 2019 13:37:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568900232; bh=4h3Wk30EhI1KisIg5rn7cH+Dc4+DOKJ7JCZLxO6zmPI=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=mwBzoNaTiK9xjLVihi6v8b+ryPsg0IP++84Wia1oIqwwNfxtQ14YDYKpBHJ3dYMni fBW0yG7v0NaSg/4OkKv0v7bY4ZNVgMqn10+8QuxFJes4isxMfpfRJSSSnElwMfLq/C aLk1/rm+0igwywEd+xuqNGYA8E4GRYk48izsxAtU= Received: by mail-wr1-f41.google.com with SMTP id y19so3158622wrd.3 for ; Thu, 19 Sep 2019 06:37:11 -0700 (PDT) X-Gm-Message-State: APjAAAU/1skrnXozK9Aok9AfZDYO5mnrx0OaoV/fbnEpldSXcnrMDM2d rOZWded7pQ8QE9NjEMxCUioz26yZSxgITGSrn70= X-Google-Smtp-Source: APXvYqzlXvVrim8rTycGbIV+PmHAEsjEw4YXguoJ0i5mulID6kS2AA+pRkt/c/jlP2DTaZZMrey31vSOQlTtKW2gKOA= X-Received: by 2002:a5d:6b49:: with SMTP id x9mr6988060wrw.80.1568900230203; Thu, 19 Sep 2019 06:37:10 -0700 (PDT) MIME-Version: 1.0 References: <20190912140256.fwbutgmadpjbjnab@willie-the-truck> <20190916181800.7lfpt3t627byoomt@willie-the-truck> In-Reply-To: From: Guo Ren Date: Thu, 19 Sep 2019 21:36:58 +0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH RFC 11/14] arm64: Move the ASID allocator code in a separate file To: Anup Patel Cc: "julien.thierry@arm.com" , "catalin.marinas@arm.com" , Palmer Dabbelt , Will Deacon , "christoffer.dall@arm.com" , Atish Patra , "julien.grall@arm.com" , "gary@garyguo.net" , "linux-riscv@lists.infradead.org" , Will Deacon , "kvmarm@lists.cs.columbia.edu" , "rppt@linux.ibm.com" , "aou@eecs.berkeley.edu" , Arnd Bergmann , "suzuki.poulose@arm.com" , "marc.zyngier@arm.com" , Paul Walmsley , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "james.morse@arm.com" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org Hi, On Tue, Sep 17, 2019 at 11:42 AM Anup Patel wrote: > > > > With a reply stating that the patch "absolutely does not work" ;) > > This patch was tested on existing HW (which does not have ASID implementation) > and tested on QEMU (which has very simplistic Implementation of ASID). > > When I asked Gary Guo about way to get access to their HW (in same patch > email thread), I did not get any reply. After so many months passed, I now > doubt the his comment "absolutely does not work". > > > > What exactly do you want people to do with that? It's an awful lot of effort to > > review this sort of stuff and given that Guo Ren is talking about sharing page > > tables between the CPU and an accelerator, maybe you're better off > > stabilising Linux for the platforms that you can actually test rather than > > getting so far ahead of yourselves that you end up with a bunch of wasted > > work on patches that probably won't get merged any time soon. > > The intention of the ASID patch was to encourage RISC-V implementations > having ASID in HW and also ensure that things don't break on existing HW. > > I don't see our efforts being wasted in trying to make Linux RISC-V feature > complete and encouraging more feature rich RISC-V CPUs. > > Delays in merging patches are fine as long as people have something to try > on their RISC-V CPU implementations. > I'm the supporter of that patch: http://archive.lwn.net:8080/linux-kernel/20190329045111.14040-1-anup.patel@wdc.com/T/#u Because it implicit hw broadcast tlb invalidation optimization. Honestly it's not suitable for remote tlb flush with software IPI, but it's still much better than current RISC-V's. I'll try it on our hardware: 910. wait a moment :) -- Best Regards Guo Ren ML: https://lore.kernel.org/linux-csky/ _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu