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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6AE3DC77B75 for ; Mon, 15 May 2023 04:38:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233993AbjEOEir (ORCPT ); Mon, 15 May 2023 00:38:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229590AbjEOEiq (ORCPT ); Mon, 15 May 2023 00:38:46 -0400 Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83AB9E48 for ; Sun, 14 May 2023 21:38:45 -0700 (PDT) Received: by mail-pf1-x42a.google.com with SMTP id d2e1a72fcca58-644d9bf05b7so6835334b3a.3 for ; Sun, 14 May 2023 21:38:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ventanamicro.com; s=google; t=1684125525; x=1686717525; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=3aTpP/j5XmZsI2M1PtQbEVHdnmyw0F8FitgytTs/n3k=; b=I+VtzDQRP5VX1htzV9toXnehk6nZVWL75nnhS3zUH/YQ8tmq6o2+eviYtIyirHm6OL p2ED2EylpVRC1Z+XlaFd52RhruwrgrTQRh6EftAh3SsJb7sQlhVkHd0oqZh1w+heMLnz MSLfUcmVGCIYYxOSFavyEOqP8TJKfv6eb4cN8450qtAZrpsLxdHHuAmLasFpQo3Woe3H K7xAcuv1dasODpATlBrf61tdvs2UsaoQmBoyOPNCSeHKTeNt6Rp3igQ38if7OoBSp0Wk 6yYmd0ccqotu6xnTwda0yO7CVP2rxJV0SiYWjvgCzAIDYid8ema2ak30GgkN4Gx7G4KG vRNg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684125525; x=1686717525; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=3aTpP/j5XmZsI2M1PtQbEVHdnmyw0F8FitgytTs/n3k=; b=RoMhSnI1TNdPcpUPhyx7Hrk3NZetK99okf5rLqc2OWOtw2e1VaJG0WiwnHCFi8CeJM fVdO4y3ajXOtcFbk8vzYsCppZ/Olcln+ttiajdzzcTXsH8QuJX5RWHQ52GM0etAA9eVT OUNUewiwO3MK3uqHOTbrTznUoRPTlEzFplhHb3TuqUv9rJ3mng7Zcfn3mj8neKO86h0+ awkVF0+T9Nu+6GsD5uHMaImdeG0ZkS1SgRKKldb01reBLKE77Cbwfsnl4mzNSADMRyBi DcxXMaK7tvuwMgvQ+7xspOxzyWzWjjmDWkyHWT/XOM9Gffuow0sGWUMCsWBc6lD43S2P sQ8Q== X-Gm-Message-State: AC+VfDzugkAAQtUtPdCwtK6K3F8B7/aucbZS4XsKKuWTbdy+xQG6FbA4 3at84rN1fDO1PtTFNZHUWKsg1Q== X-Google-Smtp-Source: ACHHUZ4GLzEA2JfT+FyfAdyb9sKhKFz1qwPptmFPwInp7Q/6hgJmlWWdC5yWKSb77JXs13LuyQUmyw== X-Received: by 2002:a05:6a00:b49:b0:648:b185:efd9 with SMTP id p9-20020a056a000b4900b00648b185efd9mr24148052pfo.11.1684125524830; Sun, 14 May 2023 21:38:44 -0700 (PDT) Received: from sunil-laptop ([106.51.191.118]) by smtp.gmail.com with ESMTPSA id b19-20020aa78713000000b00643355ff6a6sm11157378pfo.99.2023.05.14.21.38.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 14 May 2023 21:38:44 -0700 (PDT) Date: Mon, 15 May 2023 10:08:35 +0530 From: Sunil V L To: Anup Patel Cc: Conor Dooley , Palmer Dabbelt , atishp@atishpatra.org, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, conor+dt@kernel.org, heiko@sntech.de, cyy@cyyself.name, Conor Dooley , robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, Paul Walmsley , ajones@ventanamicro.com, Krste Asanovic , Andrew Waterman , Greg Favor , Mark Himelstein , Philipp Tomsich Subject: Re: [RFC 0/6] Deprecate riscv,isa DT property? Message-ID: References: <20230511-occupancy-cleat-06e532e3ea11@spud> <20230512-streak-camper-08a68afb5897@spud> <20230512-exhume-unfold-f104dd4c4cbf@spud> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Sat, May 13, 2023 at 01:17:03PM +0530, Anup Patel wrote: > On Sat, May 13, 2023 at 3:35 AM Conor Dooley wrote: > > > > +CC Greg, Mark, Krste, Philipp, Andrew, > > > > (this is LKML now, no top posting or html replies) > > > > On Fri, May 12, 2023 at 08:40:10PM +0100, Conor Dooley wrote: > > > On Fri, May 12, 2023 at 11:01:09AM -0700, Palmer Dabbelt wrote: > > > > On Thu, 11 May 2023 15:38:10 PDT (-0700), Conor Dooley wrote: > > > > > On Thu, May 11, 2023 at 03:34:24PM -0700, Atish Patra wrote: > > > > > > On Thu, May 11, 2023 at 2:47 PM Conor Dooley wrote: > > > > > > > On Thu, May 11, 2023 at 02:27:44PM -0700, Atish Patra wrote: > > > > > > > > > > > > That's more than last year at this point, and nothing has changed in the > > > > > > > documentation! Talk's cheap, ehh? > > > > > > > > > > > > > > > > > > > Yup. I will poke RVI folks to check if it still is the plan or changed !! > > > > > > > > > > Sounds good, thanks! > > > > > > There has been some movement on that front, shall see where it goes > > > :upsidedown_smile: > > > > There's been some off-list discussion prompted by Atish with some of the > > RVI spec folk, from which the upshot __appears__ to be an understanding > > that using version numbering to indicate removal of ISA features is a bad > > idea. > > I'm hoping that this results in the enshrinement of this in the ISA > > specs, so that we have something concrete to point to as the basis for > > not needing to handle version numbering. > > Certainly that'd be great for ACPI and remove concerns there. > > > > > > > > We will likely have a vendor specific string parsing logic. > > > > > > > > > > Complicating the parsing logic is the exact sort of crap that I want > > > > > to avoid. > > > > > > > > Ya, I think we're reallly overcomplicating things with the ISA strings. > > > > Let's just deprecate them and move to something that doesn't need all the > > > > bespoke string parsing. > > > > > > Versioning aside, although that removes a large part of the motivation, > > > the interface becomes quite nice: > > > of_property_present(node, "riscv,isa-extension-zicbom") > > > > My current feeling is that, rather than introducing a key-value type of > > property, adding boolean properties for extensions is the way to go > > here. The "riscv,isa" part of the DT ABI pre-dates even the ratification > > of the base extensions (and thus the removal of some features...). > > Starting again with a new property would allow us to define extensions > > as per their ratified state, rather than the intermediate & incompatible > > states that we have currently got with "riscv,isa". > > Such a model does rely on the strengthening of the wording in the > > specification. > > ISA string parsed for both DT and ACPI. > > For ACPI, moving to a per-extension bit in a bitmap and defining > a new bit with every ISA extension will be very very inconvenient > for updating the ACPI specs. We should continue the ISA string > parsing at least for ACPI. > > For DT, users can either use "riscv,isa" DT property or use boolean > DT properties. > >From ACPI perspective, the format better be backed by unpriv (or any other) spec from RVI considering it is a standard across OSs and to avoid any maintenance issues. Thanks, Sunil