From: Dave Martin <Dave.Martin@arm.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: lorenzo.pieralisi@arm.com, suzuki.poulose@arm.com,
marc.zyngier@arm.com, catalin.marinas@arm.com,
will.deacon@arm.com, linux@armlinux.org.uk, james.morse@arm.com,
robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCHv3 1/6] arm/arm64: smccc/psci: add arm_smccc_1_1_get_conduit()
Date: Tue, 13 Aug 2019 12:38:12 +0100 [thread overview]
Message-ID: <20190813113812.GW10425@arm.com> (raw)
In-Reply-To: <20190812152649.GC52896@lakrids.cambridge.arm.com>
On Mon, Aug 12, 2019 at 04:26:49PM +0100, Mark Rutland wrote:
> On Mon, Aug 12, 2019 at 04:10:43PM +0100, Dave Martin wrote:
> > On Mon, Aug 12, 2019 at 04:06:35PM +0100, Mark Rutland wrote:
> > > On Mon, Aug 12, 2019 at 04:03:29PM +0100, Dave Martin wrote:
> > > > On Fri, Aug 09, 2019 at 02:22:40PM +0100, Mark Rutland wrote:
> > > > > diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
> > > > > index 080012a6f025..df01a8579034 100644
> > > > > --- a/include/linux/arm-smccc.h
> > > > > +++ b/include/linux/arm-smccc.h
> > > > > @@ -80,6 +80,22 @@
> > > > >
> > > > > #include <linux/linkage.h>
> > > > > #include <linux/types.h>
> > > > > +
> > > > > +enum arm_smccc_conduit {
> > > > > + SMCCC_CONDUIT_NONE,
> > > >
> > > > If this is intended to have the value 0, is it worth making that
> > > > explicit? I can never remember whether enums start at 1 or 0 by
> > > > default...
> > >
> > > They start at 0. I intend that checks are done explicitly against an
> > > enum value, so I'm not sure that matters.
> >
> > Not really.
> >
> > It depends whether code like if (!arm_smccc_1_1_get_conduit()) { ... }
> > is considered sane or not.
> >
> > If we don't think people should be doing this, omitting the explicit
> > value specifier seems fine.
>
> My expectation was that they'd check explicitly against
> SMCCC_CONDUIT_NONE, since all of the existing callers care about the
> specific conduit for other reasons (e.g. patching).
>
> I also expect to wrap this in a sbusequent patch that provides helpers:
>
> * arm_smccc_1_1_available()
> * arm_smccc_1_1_call(...)
>
> ... for the cases where we just want to make a call and don't care about
> the specific conduit.
Seems reasonable.
Cheers
---Dave
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-08-13 11:40 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-09 13:22 [PATCHv3 0/6] arm/arm64: SMCCC conduit cleanup Mark Rutland
2019-08-09 13:22 ` [PATCHv3 1/6] arm/arm64: smccc/psci: add arm_smccc_1_1_get_conduit() Mark Rutland
2019-08-12 15:03 ` Dave Martin
2019-08-12 15:06 ` Mark Rutland
2019-08-12 15:10 ` Dave Martin
2019-08-12 15:26 ` Mark Rutland
2019-08-13 11:38 ` Dave Martin [this message]
2019-08-09 13:22 ` [PATCHv3 2/6] arm64: errata: use arm_smccc_1_1_get_conduit() Mark Rutland
2019-08-09 13:22 ` [PATCHv3 3/6] arm: spectre-v2: " Mark Rutland
2019-10-11 14:02 ` Catalin Marinas
2019-08-09 13:22 ` [PATCHv3 4/6] firmware/psci: use common SMCCC_CONDUIT_* Mark Rutland
2019-08-09 13:22 ` [PATCHv3 5/6] firmware: arm_sdei: " Mark Rutland
2019-08-09 13:22 ` [PATCHv3 6/6] smccc: make 1.1 macros value-returning Mark Rutland
2019-08-15 16:42 ` Will Deacon
2019-08-19 10:44 ` Mark Rutland
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190813113812.GW10425@arm.com \
--to=dave.martin@arm.com \
--cc=catalin.marinas@arm.com \
--cc=james.morse@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux@armlinux.org.uk \
--cc=lorenzo.pieralisi@arm.com \
--cc=marc.zyngier@arm.com \
--cc=mark.rutland@arm.com \
--cc=robin.murphy@arm.com \
--cc=suzuki.poulose@arm.com \
--cc=will.deacon@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).