From: Meador Inge <meador_inge@mentor.com>
To: Yoder Stuart-B08248 <B08248@freescale.com>
Cc: "Blanchard, Hollis" <Hollis_Blanchard@mentor.com>,
Wood Scott-B07421 <B07421@freescale.com>,
"devicetree-discuss@lists.ozlabs.org"
<devicetree-discuss@lists.ozlabs.org>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH 1/2] powerpc: document the MPIC device tree binding
Date: Wed, 19 Jan 2011 18:08:03 -0600 [thread overview]
Message-ID: <4D377CE3.6000608@mentor.com> (raw)
In-Reply-To: <9F6FE96B71CF29479FF1CDC8046E150306BF11@039-SN1MPN1-004.039d.mgd.msft.net>
On 01/19/2011 04:14 PM, Yoder Stuart-B08248 wrote:
>
>> +** Optional properties:
>> +
>> + - no-reset : The presence of this property indicates that the MPIC
>> + should not be reset during runtime initialization.
>> + - protected-sources : Specifies a list of interrupt sources that are
>> + not
>> + available for use and whose corresponding
>> + vectors
>> + should not be initialized. A typical use case
>> + for
>> + this property is in AMP systems where multiple
>> + independent operating systems need to share
>> + the MPIC
>> + without clobbering each other.
>
> Is "protected-sources" really needed for AMP systems to
> tell the OSes not to clobber each other? Won't each
> OS be given a device tree with only its interrupt
> sources? ...so you know what you are allowed to touch.
This was discussed a little bit already [1, 2]. The MPIC driver
currently initializes the VECPRI register for all interrupt sources,
which can lead to the aforementioned clobbering.
--
Meador Inge | meador_inge AT mentor.com
Mentor Embedded | http://www.mentor.com/embedded-software
[1]
http://lists.ozlabs.org/pipermail/devicetree-discuss/2010-December/003850.html
[2]
http://lists.ozlabs.org/pipermail/devicetree-discuss/2011-January/003936.html
WARNING: multiple messages have this Message-ID (diff)
From: Meador Inge <meador_inge-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>
To: Yoder Stuart-B08248 <B08248-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
Cc: "Blanchard,
Hollis"
<Hollis_Blanchard-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>,
Wood Scott-B07421
<B07421-KZfg59tc24xl57MIdRCFDg@public.gmane.org>,
"devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org"
<devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org>,
"linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org"
<linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org>
Subject: Re: [PATCH 1/2] powerpc: document the MPIC device tree binding
Date: Wed, 19 Jan 2011 18:08:03 -0600 [thread overview]
Message-ID: <4D377CE3.6000608@mentor.com> (raw)
In-Reply-To: <9F6FE96B71CF29479FF1CDC8046E150306BF11-TcFNo7jSaXM0vywKSws3iq4g8xLGJsHaLnY5E4hWTkheoWH0uzbU5w@public.gmane.org>
On 01/19/2011 04:14 PM, Yoder Stuart-B08248 wrote:
>
>> +** Optional properties:
>> +
>> + - no-reset : The presence of this property indicates that the MPIC
>> + should not be reset during runtime initialization.
>> + - protected-sources : Specifies a list of interrupt sources that are
>> + not
>> + available for use and whose corresponding
>> + vectors
>> + should not be initialized. A typical use case
>> + for
>> + this property is in AMP systems where multiple
>> + independent operating systems need to share
>> + the MPIC
>> + without clobbering each other.
>
> Is "protected-sources" really needed for AMP systems to
> tell the OSes not to clobber each other? Won't each
> OS be given a device tree with only its interrupt
> sources? ...so you know what you are allowed to touch.
This was discussed a little bit already [1, 2]. The MPIC driver
currently initializes the VECPRI register for all interrupt sources,
which can lead to the aforementioned clobbering.
--
Meador Inge | meador_inge AT mentor.com
Mentor Embedded | http://www.mentor.com/embedded-software
[1]
http://lists.ozlabs.org/pipermail/devicetree-discuss/2010-December/003850.html
[2]
http://lists.ozlabs.org/pipermail/devicetree-discuss/2011-January/003936.html
next prev parent reply other threads:[~2011-01-20 0:08 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-18 0:52 [PATCH 1/2] powerpc: document the MPIC device tree binding Meador Inge
2011-01-18 0:52 ` Meador Inge
2011-01-18 20:31 ` Scott Wood
[not found] ` <AANLkTi=QX4BfLvPfQDMOgmh90TtX4MQqio6AOZR8JKas@mail.gmail.com>
2011-01-18 20:21 ` Yoder Stuart-B08248
2011-01-18 20:21 ` Yoder Stuart-B08248
2011-01-19 20:24 ` Meador Inge
2011-01-19 20:38 ` Yoder Stuart-B08248
2011-01-19 20:38 ` Yoder Stuart-B08248
2011-01-19 22:14 ` Yoder Stuart-B08248
2011-01-19 22:14 ` Yoder Stuart-B08248
2011-01-20 0:08 ` Meador Inge [this message]
2011-01-20 0:08 ` Meador Inge
2011-01-20 15:50 ` Yoder Stuart-B08248
2011-01-20 15:50 ` Yoder Stuart-B08248
2011-01-27 23:50 ` Meador Inge
2011-01-27 23:50 ` Meador Inge
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