From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3] [RFC] arm: use PSCI if available
Date: Wed, 27 Mar 2013 17:50:51 +0000 [thread overview]
Message-ID: <201303271750.52015.arnd@arndb.de> (raw)
In-Reply-To: <20130327170555.GA20990@mudshark.cambridge.arm.com>
On Wednesday 27 March 2013, Will Deacon wrote:
> The channel is common, sure, but I wouldn't expect the semantics of each
> call to be identical between firmware implementations (going back to my
> previous examples of CPU IDs and implementation-defined state parameters).
>
> If a platform happens to have an id-mapping from smp_operations to psci,
> then I still think there should be an indirection in there so that we have
> the flexibility to change the smp_operations if we wish and not give
> platforms the false impression that these two things are equivalent.
I think the only reasonably implementation for psci is if we can assume
that each callback with a specific property name has a well-defined behavior,
and we should mandate that every platform that implements the callbacks
we need for SMP actually implements them according to the spec.
What would be the point of a standard psci interface if the specific
implementation are not required to follow the same semantics?
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@arndb.de>
To: Will Deacon <will.deacon@arm.com>
Cc: Rob Herring <robherring2@gmail.com>,
Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
"linux@arm.linux.org.uk" <linux@arm.linux.org.uk>,
"nico@linaro.org" <nico@linaro.org>,
Marc Zyngier <Marc.Zyngier@arm.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v3] [RFC] arm: use PSCI if available
Date: Wed, 27 Mar 2013 17:50:51 +0000 [thread overview]
Message-ID: <201303271750.52015.arnd@arndb.de> (raw)
In-Reply-To: <20130327170555.GA20990@mudshark.cambridge.arm.com>
On Wednesday 27 March 2013, Will Deacon wrote:
> The channel is common, sure, but I wouldn't expect the semantics of each
> call to be identical between firmware implementations (going back to my
> previous examples of CPU IDs and implementation-defined state parameters).
>
> If a platform happens to have an id-mapping from smp_operations to psci,
> then I still think there should be an indirection in there so that we have
> the flexibility to change the smp_operations if we wish and not give
> platforms the false impression that these two things are equivalent.
I think the only reasonably implementation for psci is if we can assume
that each callback with a specific property name has a well-defined behavior,
and we should mandate that every platform that implements the callbacks
we need for SMP actually implements them according to the spec.
What would be the point of a standard psci interface if the specific
implementation are not required to follow the same semantics?
Arnd
next prev parent reply other threads:[~2013-03-27 17:50 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-27 12:50 [PATCH v3] [RFC] arm: use PSCI if available Stefano Stabellini
2013-03-27 12:50 ` Stefano Stabellini
2013-03-27 12:50 ` Stefano Stabellini
2013-03-27 13:35 ` Marc Zyngier
2013-03-27 13:35 ` Marc Zyngier
2013-03-27 16:20 ` Rob Herring
2013-03-27 16:20 ` Rob Herring
2013-03-27 13:38 ` Will Deacon
2013-03-27 13:38 ` Will Deacon
2013-03-27 16:23 ` Stefano Stabellini
2013-03-27 16:23 ` Stefano Stabellini
2013-03-27 16:35 ` Rob Herring
2013-03-27 16:35 ` Rob Herring
2013-03-27 17:10 ` Stefano Stabellini
2013-03-27 17:10 ` Stefano Stabellini
2013-03-27 17:24 ` Nicolas Pitre
2013-03-27 17:24 ` Nicolas Pitre
2013-03-27 18:22 ` Stefano Stabellini
2013-03-27 18:22 ` Stefano Stabellini
2013-03-27 17:45 ` Rob Herring
2013-03-27 17:45 ` Rob Herring
2013-03-27 18:03 ` Arnd Bergmann
2013-03-27 18:03 ` Arnd Bergmann
2013-03-27 18:14 ` Stefano Stabellini
2013-03-27 18:14 ` Stefano Stabellini
2013-03-27 17:23 ` Will Deacon
2013-03-27 17:23 ` Will Deacon
2013-03-28 12:48 ` Stefano Stabellini
2013-03-28 12:48 ` Stefano Stabellini
2013-03-28 14:51 ` Nicolas Pitre
2013-03-28 14:51 ` Nicolas Pitre
2013-03-28 15:04 ` Rob Herring
2013-03-28 15:04 ` Rob Herring
2013-03-28 15:36 ` Stefano Stabellini
2013-03-28 15:36 ` Stefano Stabellini
2013-03-28 15:39 ` Nicolas Pitre
2013-03-28 15:39 ` Nicolas Pitre
2013-03-28 16:00 ` Will Deacon
2013-03-28 16:00 ` Will Deacon
2013-03-28 16:06 ` Nicolas Pitre
2013-03-28 16:06 ` Nicolas Pitre
2013-03-28 16:20 ` Stefano Stabellini
2013-03-28 16:20 ` Stefano Stabellini
2013-03-28 18:38 ` Rob Herring
2013-03-28 18:38 ` Rob Herring
2013-03-29 13:22 ` Stefano Stabellini
2013-03-29 13:22 ` Stefano Stabellini
2013-03-29 13:54 ` Rob Herring
2013-03-29 13:54 ` Rob Herring
2013-03-29 14:47 ` Stefano Stabellini
2013-03-29 14:47 ` Stefano Stabellini
2013-03-27 16:33 ` Rob Herring
2013-03-27 16:33 ` Rob Herring
2013-03-27 17:05 ` Will Deacon
2013-03-27 17:05 ` Will Deacon
2013-03-27 17:50 ` Arnd Bergmann [this message]
2013-03-27 17:50 ` Arnd Bergmann
2013-03-27 18:12 ` Will Deacon
2013-03-27 18:12 ` Will Deacon
2013-03-27 19:10 ` Rob Herring
2013-03-27 19:10 ` Rob Herring
2013-03-27 19:14 ` Arnd Bergmann
2013-03-27 19:14 ` Arnd Bergmann
2013-03-27 14:55 ` Rob Herring
2013-03-27 14:55 ` Rob Herring
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