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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 B0E48C433EF for ; Thu, 23 Sep 2021 11:51:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 903C060F44 for ; Thu, 23 Sep 2021 11:51:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240699AbhIWLwl (ORCPT ); Thu, 23 Sep 2021 07:52:41 -0400 Received: from smtp-relay-internal-0.canonical.com ([185.125.188.122]:46044 "EHLO smtp-relay-internal-0.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240636AbhIWLwg (ORCPT ); Thu, 23 Sep 2021 07:52:36 -0400 Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-internal-0.canonical.com (Postfix) with ESMTPS id 3E3373F32A for ; Thu, 23 Sep 2021 11:51:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1632397864; bh=wGcNO2IXTBVLJmMzaDNfXw1CRQSpWdqfS3q/Z8Q4M1Y=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=tKMEvmjCEgtN6yyDqe6vn+SRVDXCZIObXIlOxXPPiwI5CwtAhvyR3S9JZg3FZyir5 8ULqu0ZpQv2vd50OX3mGoLt9fWnrWpiubLy71iPWV/h2Iw6KeLlctjzA0yJNmr0uzX uOoG/CvZqyhy4H4qPYwobFjm+nLEnVb4QfAsoWkChJIycj9lbtiodr9y5I71or6NPg akWx945NP8CeN2yze3o3xTQlncFLLyprMULW9L6BaIHjknw455xq93Qc0lW4AUBq6N PhJSnMx0jvx8AVXpMCXIvvsOzyfGA1AZmWSECHl7mc/V1eNEmnDQOAEzvqsfuosaok SCtLi1nNzXA3Q== Received: by mail-ed1-f72.google.com with SMTP id r23-20020a50d697000000b003d824845066so6528839edi.8 for ; Thu, 23 Sep 2021 04:51:04 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=wGcNO2IXTBVLJmMzaDNfXw1CRQSpWdqfS3q/Z8Q4M1Y=; b=Q2AoRO0tIbWnN0Gpt0NvbXpSCz/RkL1UXLPHT/2creVCqcAUS+S/iWC2neeUPyP4sR QISL52b/29EQalRmtdTQu8HJcftiQi+ez9q3ITuN0Rukq33Fj2x1DnII86QmYlI7AAXw Dk/5TN4cRMeLkYlOPFpbVICEu+PvoAV14cCbGECnqLTqJTaGOOMWS5lSpZsBCVvuKzUi wGSc5FIszWhDGT97Cz1tsYkVstVFH1643MRqYH88lQx1eOqLNmEX1Yc8vYjybNsE1Zek eqAiBNn2ICKdYe0kjfG2icgqv2Ip4hCO8twKu3aeS9F9Hu4jB4EAXEm+4VStpmt/UN95 foWg== X-Gm-Message-State: AOAM531Z+ksxnScqCaUL4aooXbLa9CezqneUAnlsKsqFeFNhmEwr9pjD zJIi9YN+O5H/LFWpbs5+A83n3A+BFvdsgCQyE77/Pv9Ko5nfaG+qeSPUSWgAYW4nWreAfVc8s5E OjxTSMqV0H1cH3CvjFtYB9X7ol6/cxOl0k+44tPbJXdpJv+9aXszbAxIXDw== X-Received: by 2002:aa7:db85:: with SMTP id u5mr4876802edt.234.1632397863961; Thu, 23 Sep 2021 04:51:03 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyzN+eiUB6TLkCud6NtqS90/s5C7jzCEwCWLoZO5rT0CasG/3cmMrbqmMTzSzy8MtmxB9LUuh7ZBIDENSSGBa0= X-Received: by 2002:aa7:db85:: with SMTP id u5mr4876783edt.234.1632397863817; Thu, 23 Sep 2021 04:51:03 -0700 (PDT) MIME-Version: 1.0 References: <20210923072716.913826-1-guoren@kernel.org> <6d7b1668c1f562a5ef426bb2519f9784@mailhost.ics.forth.gr> <0861cc74d3886e685e9aa5d13ddcd781@mailhost.ics.forth.gr> <16de95480d279b086cf0c612461e4235@mailhost.ics.forth.gr> <88696248a0c19a5dff660354b837514d@mailhost.ics.forth.gr> In-Reply-To: <88696248a0c19a5dff660354b837514d@mailhost.ics.forth.gr> From: Alexandre Ghiti Date: Thu, 23 Sep 2021 13:50:52 +0200 Message-ID: Subject: Re: [PATCH] riscv: Add RISC-V svpbmt extension To: Nick Kossifidis Cc: Philipp Tomsich , Anup Patel , Guo Ren , Anup Patel , Atish Patra , Palmer Dabbelt , =?UTF-8?Q?Christoph_M=C3=BCllner?= , Christoph Hellwig , liush , wefu@redhat.com, =?UTF-8?B?V2VpIFd1ICjlkLTkvJ8p?= , Drew Fustini , linux-riscv , "linux-kernel@vger.kernel.org List" , taiten.peng@canonical.com, Aniket Ponkshe , Heinrich Schuchardt , Gordan Markus , Guo Ren , Arnd Bergmann , Chen-Yu Tsai , Maxime Ripard , Daniel Lustig , Greg Favor , Andrea Mondelli , Jonathan Behrens , Xinhaoqu , Bill Huffman , Allen Baum , Josh Scheid , Richard Trauben Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 23, 2021 at 12:11 PM Nick Kossifidis wrote: > > =CE=A3=CF=84=CE=B9=CF=82 2021-09-23 13:04, Philipp Tomsich =CE=AD=CE=B3= =CF=81=CE=B1=CF=88=CE=B5: > > > > How if we expand this to a mmu subnode in cpu@x and add a booleans for > > adornments like svnapot and svpbmt? > > The older mmu-type could then treated to indicate a mmu w/o any > > adornments specified. I am aware that this generates an additional > > parsing-path that will be maintained, but it will allow future > > properties to be grouped. > > > > cpu@0 { > > ... > > mmu { > > type =3D "riscv,sv39"; > > supports-svpbmt; > > } > > ... > > } > > I was about to propose the same thing, we can do this now without > breaking backwards compatibility, we don't really use mmu-type property > at this point, we are either sv39 or nommu. Indeed, this property is only informative and not useful since we can directly "ask" the hw what it supports (cf sv48 patchset). And it cannot actually be used to force a certain svXX since reading the device tree happens way too late in the boot process (I have this issue with my sv48 patchset where I used to read the device tree to set the size of the address space, but it actually breaks KASAN). Isn't there a way to know if it supports svPBMT at runtime? Alex > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv