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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 121E6EB64D9 for ; Thu, 29 Jun 2023 11:40:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type:Cc: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=AFwgVSNB06877ftxnb6TL9kPPufcBZbqZkpntkq6vOQ=; b=a6UdUX4JCTOofgfk/PHwUNIYQW cTQnwDHnoVcUfnESxIb7pKAjAHhuO0aDhgCGHPh7J9qdHp3ucRkR29W4PHuogG5OCoueBwqQOYtka JBar0nVcAFL9TbOvTS7Zre31SFxAEy1tu0kHdPc0DaetvooHwzRVnPvt5NpCkSOdqKLvNKTUymMmc +x8TRcaZMTyC6Sa6sae7VIM5S51rmFhdPi/N7E+X6qqv4FWo5JFPL9kUwxsickVwSuysskyEwrrQm dXXOJVMx+3cCoRtygQFvYMimCAkZS3zx8IzYwAkYahVQcqXFZE5ZGtzpjnmZUOP8PONIHiNlFYGnJ 8OFPb8kw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qEq0m-000yrX-1d; Thu, 29 Jun 2023 11:40:32 +0000 Received: from esa.microchip.iphmx.com ([68.232.154.123]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qEq0j-000yp3-2u for linux-riscv@lists.infradead.org; Thu, 29 Jun 2023 11:40:31 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1688038830; x=1719574830; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=sAr1yW8ms9qKdVY87lLEN9RPbOLSC7vvBYXs60c7FDI=; b=lcwhRqb7mRQuKn3YZKYNA2NXSSq0yb2EWKRTiHRFSQWoI45o7lbCmlwy shc6pZLbWmuDp3UkwLiwhSA948LJBxcadQ73Z2iROy3bpv9Ko2DSSHXf0 pBUq92jyNpnBxGODdqtrAh5v79O8HUHWiBaE1SJT0QOxmC7QBZHS6obzO xS7A6/AeLWXdPqI8cgt18FVohWS0c1Q1RrB074yZnKGTTK+sOWiJuOILW vjg+ucO++injXRJmJ7OhhN0DOg9QAU8K8yw/ZjtqNzi+kdEA/ke5xs+Z5 y3MC1V+/jH1dnkNojxopnLm1OuxBOnDcWdH0e5RR3QsL36MyFbrYyqBx8 Q==; X-IronPort-AV: E=Sophos;i="6.01,168,1684825200"; d="asc'?scan'208";a="218175038" X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa4.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 29 Jun 2023 04:40:24 -0700 Received: from chn-vm-ex02.mchp-main.com (10.10.85.144) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Thu, 29 Jun 2023 04:40:22 -0700 Received: from wendy (10.10.115.15) by chn-vm-ex02.mchp-main.com (10.10.85.144) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21 via Frontend Transport; Thu, 29 Jun 2023 04:40:20 -0700 Date: Thu, 29 Jun 2023 12:39:51 +0100 From: Conor Dooley To: Andrew Jones Subject: Re: [PATCH v2 10/10] RISC-V: provide a Kconfig option to disable parsing "riscv,isa" Message-ID: <20230629-deceit-macarena-2a744ac70148@wendy> References: <20230629-rebuttal-vagueness-a699deb7c7b3@wendy> <20230629-resilient-grievance-d782163b09d6@wendy> <20230629-a80f112e6ed4158080867694@orel> MIME-Version: 1.0 In-Reply-To: <20230629-a80f112e6ed4158080867694@orel> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230629_044029_998630_7C0B3CDF X-CRM114-Status: GOOD ( 31.15 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, Albert Ou , linux-kernel@vger.kernel.org, conor@kernel.org, Rob Herring , palmer@dabbelt.com, Palmer Dabbelt , Krzysztof Kozlowski , Paul Walmsley , linux-riscv@lists.infradead.org, Heiko Stuebner , Evan Green Content-Type: multipart/mixed; boundary="===============8605531420383178494==" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org --===============8605531420383178494== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Sze7hK0PNyYVfnYw" Content-Disposition: inline --Sze7hK0PNyYVfnYw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jun 29, 2023 at 11:31:33AM +0200, Andrew Jones wrote: > On Thu, Jun 29, 2023 at 09:28:56AM +0100, Conor Dooley wrote: > > As it says on the tin, provide a Kconfig option to disabling parsing the > > "riscv,isa" devicetree property. Hide the option behind NONPORTABLE so > > that only those willing to keep the pieces enable it, and make sure the > > default kernel contains the fallback code. > >=20 > > Suggested-by: Palmer Dabbelt > > Signed-off-by: Conor Dooley > > --- > > arch/riscv/Kconfig | 16 ++++++++++++++++ > > arch/riscv/kernel/cpu.c | 3 +++ > > arch/riscv/kernel/cpufeature.c | 2 +- > > 3 files changed, 20 insertions(+), 1 deletion(-) > >=20 > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > index 1d39efe2b940..0e1909ac5947 100644 > > --- a/arch/riscv/Kconfig > > +++ b/arch/riscv/Kconfig > > @@ -291,6 +291,22 @@ config NONPORTABLE > > =20 > > If unsure, say N. > > =20 > > +config NO_RISCV_ISA_FALLBACK > > + bool "Permit falling back to parsing riscv,isa for extension support" > > + depends on NONPORTABLE > > + help > > + Parsing the "riscv,isa" devicetree property has been deprecated and > > + replaced by a list of explicitly defined strings. For compatibility > > + with existing platforms, the kernel will fall back to parsing the > > + "riscv,isa" property if the replacements are not found. > > + > > + Selecting Y here will result in a kernel without this fallback, and > > + will not work on platforms where the devicetree does not contain the > > + replacement properties of "riscv,isa-base" and > ^ spacing issue Huh, weird. Given the tab followed by spaces, it must have snuck in during reflow of the text after some rewording. Wonder how I missed it, given that... > Should we also have a kernel command line option, 'isa_fallback', where > without this config the command line option is not necessary to fallback, > but, with this config, no fallback will be done unless 'isa_fallback' is > provided? I don't know, maybe I have the wrong end of the stick but it feels a bit premature for something that may never not be hidden behind NONPORTABLE? Perhaps that could be left for a point in time where the default value of the symbol changes, or the dependency on NONPORTABLE is removed? Cheers, Conor. --Sze7hK0PNyYVfnYw Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZJ1thwAKCRB4tDGHoIJi 0vzDAQDP9JlWlUGwMAoSKSxFjb6GGIDX8Mbn07UsWcWTcqMgAgD+JkZNTy1Vf7gU LgyClwNQJHHQVT0Xj7BVnlyqzAn93Aw= =bH7a -----END PGP SIGNATURE----- --Sze7hK0PNyYVfnYw-- --===============8605531420383178494== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv --===============8605531420383178494==--