From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan =?utf-8?Q?Neusch=C3=A4fer?= Subject: Re: [patches] Re: [PATCH] dt-bindings: Add a RISC-V SBI firmware node Date: Tue, 21 Nov 2017 02:08:44 +0100 Message-ID: <20171121010843.4nmndskaoslqcyyh@latitude> References: <20171120202856.nptoirhm5luiamt7@latitude> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="kuoznduu6gtgogwf" Return-path: Content-Disposition: inline In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: patches-q3qR2WxjNRFS9aJRtSZj7A@public.gmane.org Cc: j.neuschaefer-hi6Y0CQ0nG0@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org --kuoznduu6gtgogwf Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Nov 20, 2017 at 01:28:01PM -0800, Palmer Dabbelt wrote: [...] > > > +++ b/Documentation/devicetree/bindings/firmware/riscv.sbi.txt > >=20 > > Nit: Other bindings use either a comma (as in the compatible string, > > "riscv,sbi.txt") or a dash (vendor-product.txt, "riscv-sbi.txt") in the > > file name. >=20 > That was just a typo, I'll fix it. Ok > > > @@ -0,0 +1,20 @@ > > > +RISC-V Supervisor Binary Interface (SBI) > > > + > > > +The RISC-V privileged ISA specification mandates the presence of a s= upervisor > > > +binary interface that performs some operations which might otherwise= require > > > +particularly complicated instructions. This interface includes > > > +inter-processor interrupts, TLB flushes, i-cache and TLB shootdowns,= a > > > +console, and power management. > > > + > > > +Required properties: > > > +- compatible: must contain one of the following > > > + * "riscv,sbi" for the SBI defined by the privileged specification o= f the > > > + system. > >=20 > > "of the system" seems to imply that different RISC-V systems (different > > RISC-V implementations) can have different privileged specifications. >=20 > Actually, that was intentional -- I wrote it this way because different > RISC-V systems do have different privileged specifications. The RISC-V > specifications aren't frozen in time, they're just guaranteed to be > compatible in the future. For example, the user ISA document has been > updated multiple times (the C spec, eliminating some unspecified behavior) > and will continue to be updated (V and other extensions, the memory model= ). > The privileged spec will be updated in a compatible way just like the user > spec will be -- I know there's at least hypervisor support in the works, = and > I saw some things to remove undefined behavior go past as well. >=20 > In a similar fashion, the ABI and SBI will continue to evolve. For examp= le, > we'll probably add new system calls to extend the user ABI and new hyper > calls to extend the SBI. My problem with the wording was that the OS somehow has to know which version and variant of the SBI it is talking to -- either through in-band communication (an SBI call to request SBI information, etc.), or through devicetree or similar mechanisms. >=20 > > I think it's better to refer to concrete documents, that don't depend on > > the rest of the system, instead. Either: Thanks, Jonathan Neusch=C3=A4fer --kuoznduu6gtgogwf Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJaE3yTAAoJEAgwRJqO81/bgoUQALiRczHL4V5hCqRjiIFNEt2M um/4Az9jtVPSMYpIP5jc4iYGqwZ7S/0k38wNR3cg4StLSCNFG9fZK7X4oefWWTjo ZMB4c2I2twrse6mMmNSbEGKCOJ/sR40Uk80EocTC/PFOfNYhEcrT1i5kLqZC+gDx XqHwOM0mFJbXpj0KW+P39Vt8P95sFLI669NuIe9ymtNborT1hLwGCgMcm7Fv9Xyh 5jGmtWkYwwrlPTYnDKq4ZJuhRgz1yNsZLb/QiF4HklSBeXSfjmh7E09Urn+/eZSl zdIFu/96GE6nvkHY3+ZmegH8OiV0kaqw4/WiyKhHS2itWGwI+81ussY3DIuCi3YC ojv7wMJgwgUhJc83PC3jGiv6kzojp3ssw18CCr2NXwAjlXrgMi0qGCKVy9k3DTX6 6BBMV50BFLy41QXKyrJY6oOLwR2jHVWmfYSa9AhBawZ1Gz3WiEjm4GQl8SqY7Wg+ p3lX+C2gSkbym0TaLcBgveHd3NsM1QbmUO9y9LplL2hhh8yuq0Ce5S6F8rV0iuQW 7HJ9PNux84EBmdhJvORKmx5ZLTgxZAwL0u5zTpYoIgs/o2CjprN9mAqgNoQO5zJC xbKnciwRXWqxE9rf0T94E3nis/hwbUK9ZhTwUW2DCjPwAl8BHeowFuvoIXuq8GIn tDL8TIIn04e3U9THiDtM =4dtp -----END PGP SIGNATURE----- --kuoznduu6gtgogwf-- -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html