From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4A4DA188CDF; Wed, 5 Jun 2024 16:55:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717606504; cv=none; b=D+B+Mydfx9M82x4iPNVWZf/7frXQiG/3g1/f477iGG87zrsblpwWd8E24xKDnVtwIN828x/Hp5kMm2EDcwR888qdt/VBAUM9UGYbn4V9155KNQRnAEkkWpsDzISEvUoIqOtDuh+/K9/vBHMKPBPTfuhqCtQeumJuyzZtEPLvY9o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717606504; c=relaxed/simple; bh=BSnD9wLTtKbSKikywrrQT5l9mkvhTFfOEYd7ndU0zhg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rQ15AAeM6oN2klyC0vFlO1qBf1EJQnT5GutE9Lc7tYB9hJy+A6Sl0N46Ew6mI7alnetITM8Xh9czw/eiXLUZuz4wANj97E1BEhE+0UMGItlFlApceC3QBbCtJ5bKE/AMVhxpY2LrmQ9ELejh++PmDEmAHYM4oqWRQN/n9B5eMd0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=e5XCRj96; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="e5XCRj96" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BBDE3C3277B; Wed, 5 Jun 2024 16:55:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1717606503; bh=BSnD9wLTtKbSKikywrrQT5l9mkvhTFfOEYd7ndU0zhg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=e5XCRj96A0ShjEuilfFCPUt4VolsLcZBGYj5R/qcp0O9NFkBlt7kYC/ztC/cGPfpD iGJFKR26NPrn5yfFhuWHMgyr9kg+rhDoxOX4Vdhx6kfTxWbqItMTK+6YiOnBXBglVC HWWR9KaQxWJJreCrwXjsAxFwE8TN+gC0TLb4INkB82SnBIhlAsDGifzXeaeB7M7E6h WYAbBMfA4GdYLqlVDemcs65Yny7KeRuSvlouZvDIZPP8CH5Q3FFNoDLqikyM4q9aFT 3ywJLHXhmbWc63yE8SD5XmV+sSwDwAfj4mx+b5SM5Yi6lqKQnhd2Wfq6oW5/OTJUec Wf037EwFDJ3Ew== Date: Wed, 5 Jun 2024 17:54:58 +0100 From: Conor Dooley To: Yong-Xuan Wang Cc: linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, apatel@ventanamicro.com, alex@ghiti.fr, ajones@ventanamicro.com, greentime.hu@sifive.com, vincent.chen@sifive.com, Rob Herring , Krzysztof Kozlowski , Paul Walmsley , Palmer Dabbelt , Albert Ou , devicetree@vger.kernel.org Subject: Re: [PATCH v5 2/4] dt-bindings: riscv: Add Svade and Svadu Entries Message-ID: <20240605-atrium-neuron-c2512b34d3da@spud> References: <20240605121512.32083-1-yongxuan.wang@sifive.com> <20240605121512.32083-3-yongxuan.wang@sifive.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="MuN5kP8SHGJqYdTt" Content-Disposition: inline In-Reply-To: <20240605121512.32083-3-yongxuan.wang@sifive.com> --MuN5kP8SHGJqYdTt Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jun 05, 2024 at 08:15:08PM +0800, Yong-Xuan Wang wrote: > Add entries for the Svade and Svadu extensions to the riscv,isa-extensions > property. >=20 > Signed-off-by: Yong-Xuan Wang > --- > .../devicetree/bindings/riscv/extensions.yaml | 30 +++++++++++++++++++ > 1 file changed, 30 insertions(+) >=20 > diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Do= cumentation/devicetree/bindings/riscv/extensions.yaml > index 468c646247aa..1e30988826b9 100644 > --- a/Documentation/devicetree/bindings/riscv/extensions.yaml > +++ b/Documentation/devicetree/bindings/riscv/extensions.yaml > @@ -153,6 +153,36 @@ properties: > ratified at commit 3f9ed34 ("Add ability to manually trigger > workflow. (#2)") of riscv-time-compare. > =20 > + - const: svade > + description: | > + The standard Svade supervisor-level extension for raising pa= ge-fault > + exceptions when PTE A/D bits need be set as ratified in the = 20240213 > + version of the privileged ISA specification. > + > + Both Svade and Svadu extensions control the hardware behavio= r when > + the PTE A/D bits need to be set. The default behavior for th= e four > + possible combinations of these extensions in the device tree= are: > + 1. Neither svade nor svadu in DT: default to svade. I think this needs to be expanded on, as to why nothing means svade. > + 2. Only svade in DT: use svade. That's a statement of the obvious, right? > + 3. Only svadu in DT: use svadu. This is not relevant for Svade. > + 4. Both svade and svadu in DT: default to svade (Linux can s= witch to > + svadu once the SBI FWFT extension is available). "The privilege level to which this devicetree has been provided can switch = to Svadu if the SBI FWFT extension is available". > + - const: svadu > + description: | > + The standard Svadu supervisor-level extension for hardware u= pdating > + of PTE A/D bits as ratified at commit c1abccf ("Merge pull r= equest > + #25 from ved-rivos/ratified") of riscv-svadu. > + > + Both Svade and Svadu extensions control the hardware behavio= r when > + the PTE A/D bits need to be set. The default behavior for th= e four > + possible combinations of these extensions in the device tree= are: @Anup/Drew/Alex, are we missing some wording in here about it only being valid to have Svadu in isolation if the provider of the devicetree has actually turned on Svadu? The binding says "the default behaviour", but it is not the "default" behaviour, the behaviour is a must AFAICT. If you set Svadu in isolation, you /must/ have turned it on. If you set Svadu and Svade, you must have Svadu turned off? > + 1. Neither svade nor svadu in DT: default to svade. > + 2. Only svade in DT: use svade. These two are not relevant to Svadu, I'd leave them out. > + 3. Only svadu in DT: use svadu. Again, statement of the obvious? > + 4. Both svade and svadu in DT: default to svade (Linux can s= witch to > + svadu once the SBI FWFT extension is available). Same here as in the Svade entry. Thanks, Conor. --MuN5kP8SHGJqYdTt Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZmCYYgAKCRB4tDGHoIJi 0tLVAQDaJxypeK+klc9eSIXgb1/wgPLmEylTnc8/4ceKF/GFnwEAq4ysX3JMpe/B tD+9p+XFfXCPa2GD2rvlTIT6YJMYuwI= =Q4pd -----END PGP SIGNATURE----- --MuN5kP8SHGJqYdTt--