From: Will Deacon <will.deacon@arm.com>
To: Stuart Yoder <stuart.yoder@freescale.com>
Cc: Varun Sethi <Varun.Sethi@freescale.com>,
Mark Rutland <Mark.Rutland@arm.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-samsung-soc@vger.kernel.org"
<linux-samsung-soc@vger.kernel.org>,
Arnd Bergmann <arnd@arndb.de>, Pawel Moll <Pawel.Moll@arm.com>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Grant Grundler <grundler@chromium.org>,
Stephen Warren <swarren@wwwdotorg.org>,
Rob Herring <robh+dt@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Marc Zyngier <Marc.Zyngier@arm.com>,
Linux IOMMU <iommu@lists.linux-foundation.org>,
Thierry Reding <thierry.reding@gmail.com>,
Kumar Gala <galak@codeaurora.org>,
"linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>,
Cho KyongHo <pullip.cho@samsung.com>,
Dave P Martin <Dave.Martin@arm.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2] devicetree: Add generic IOMMU device tree bindings
Date: Wed, 18 Jun 2014 10:29:06 +0100 [thread overview]
Message-ID: <20140618092906.GA32699@arm.com> (raw)
In-Reply-To: <7c03c5cffa174b20962bff3b09de0eb8@DM2PR03MB352.namprd03.prod.outlook.com>
On Tue, Jun 17, 2014 at 03:50:25PM +0100, Stuart Yoder wrote:
> > > I think for simple masters (i.e. those that have all their StreamIDs
> > > under control of one driver), then setting something during attach (or
> > > add?) based on the DT could work pretty well. The other case is when we
> > > have masters behind a bridge (such as a PCI RC). In this case, it might
> > > actually be better to ask the bridge for the IDs and let it sort out
> > the
> > > allocation itself. That would also move the RequesterID -> StreamID
> > > mapping out of the SMMU code.
> > >
> > > What do you think?
> > The PCI bus iommu group creation code would be part of the SMMU driver
> > (it is handled by other IOMMU drivers as well). My understanding is that
> > there would be one is to one correspondence between the requestor ID and
> > the iommu group. May be, we can have an API provided by the PCI bridge
> > (architecture specific) for setting the stream ID.
>
> I think Will is suggesting something along those lines-- I think it's a
> question of where the streamID allocation happens. You could
> either do something like the following in the SMMU driver when attaching
> a PCI device:
>
> id = alloc_stream_id(...);
> pci_set_streamid(pci-dev, id);
>
> or
>
> id = pci_get_streamid(pci-dev);
>
> ...i.e the PCI RC could allocate (from some TBD
> allocator) and set the stream ID itself.
>
> Not sure how big a deal it is to extend PCI RC interfaces for
> something like that.
I think both interfaces have their place; the latter for hotpluggable buses
and the former for static allocation (i.e. set once). The only way to see
how well it works is to try implementing it, I guess.
Will
WARNING: multiple messages have this Message-ID (diff)
From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] devicetree: Add generic IOMMU device tree bindings
Date: Wed, 18 Jun 2014 10:29:06 +0100 [thread overview]
Message-ID: <20140618092906.GA32699@arm.com> (raw)
In-Reply-To: <7c03c5cffa174b20962bff3b09de0eb8@DM2PR03MB352.namprd03.prod.outlook.com>
On Tue, Jun 17, 2014 at 03:50:25PM +0100, Stuart Yoder wrote:
> > > I think for simple masters (i.e. those that have all their StreamIDs
> > > under control of one driver), then setting something during attach (or
> > > add?) based on the DT could work pretty well. The other case is when we
> > > have masters behind a bridge (such as a PCI RC). In this case, it might
> > > actually be better to ask the bridge for the IDs and let it sort out
> > the
> > > allocation itself. That would also move the RequesterID -> StreamID
> > > mapping out of the SMMU code.
> > >
> > > What do you think?
> > The PCI bus iommu group creation code would be part of the SMMU driver
> > (it is handled by other IOMMU drivers as well). My understanding is that
> > there would be one is to one correspondence between the requestor ID and
> > the iommu group. May be, we can have an API provided by the PCI bridge
> > (architecture specific) for setting the stream ID.
>
> I think Will is suggesting something along those lines-- I think it's a
> question of where the streamID allocation happens. You could
> either do something like the following in the SMMU driver when attaching
> a PCI device:
>
> id = alloc_stream_id(...);
> pci_set_streamid(pci-dev, id);
>
> or
>
> id = pci_get_streamid(pci-dev);
>
> ...i.e the PCI RC could allocate (from some TBD
> allocator) and set the stream ID itself.
>
> Not sure how big a deal it is to extend PCI RC interfaces for
> something like that.
I think both interfaces have their place; the latter for hotpluggable buses
and the former for static allocation (i.e. set once). The only way to see
how well it works is to try implementing it, I guess.
Will
next prev parent reply other threads:[~2014-06-18 9:29 UTC|newest]
Thread overview: 215+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-23 20:33 [PATCH v2] devicetree: Add generic IOMMU device tree bindings Thierry Reding
[not found] ` <1400877218-4113-1-git-send-email-thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2014-05-30 13:16 ` Rob Herring
2014-05-30 13:16 ` Rob Herring
2014-05-30 13:16 ` Rob Herring
[not found] ` <CAL_JsqKumG1PSFoVfeGpLLG+MjXFeF4aUjun=vv1BJpaxk0Byg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-05-30 19:06 ` Arnd Bergmann
2014-05-30 19:06 ` Arnd Bergmann
2014-05-30 19:06 ` Arnd Bergmann
2014-05-30 19:29 ` Hiroshi Doyu
2014-05-30 19:29 ` Hiroshi Doyu
2014-05-30 19:29 ` Hiroshi Doyu
2014-05-30 19:54 ` Arnd Bergmann
2014-05-30 19:54 ` Arnd Bergmann
2014-05-30 19:54 ` Arnd Bergmann
2014-06-01 9:55 ` Will Deacon
2014-06-01 9:55 ` Will Deacon
2014-06-01 9:55 ` Will Deacon
[not found] ` <20140601095546.GA8625-5wv7dgnIgG8@public.gmane.org>
2014-06-04 13:39 ` Thierry Reding
2014-06-04 13:39 ` Thierry Reding
2014-06-04 13:39 ` Thierry Reding
2014-06-04 13:44 ` Thierry Reding
2014-06-04 13:44 ` Thierry Reding
2014-06-04 13:44 ` Thierry Reding
2014-06-04 13:53 ` Arnd Bergmann
2014-06-04 13:53 ` Arnd Bergmann
2014-06-04 13:53 ` Arnd Bergmann
2014-06-04 13:56 ` Will Deacon
2014-06-04 13:56 ` Will Deacon
2014-06-04 13:56 ` Will Deacon
[not found] ` <20140604135600.GD6644-5wv7dgnIgG8@public.gmane.org>
2014-06-04 14:01 ` Arnd Bergmann
2014-06-04 14:01 ` Arnd Bergmann
2014-06-04 14:01 ` Arnd Bergmann
2014-06-04 16:39 ` Will Deacon
2014-06-04 16:39 ` Will Deacon
2014-06-04 16:39 ` Will Deacon
2014-05-30 19:31 ` Rob Herring
2014-05-30 19:31 ` Rob Herring
2014-05-30 19:31 ` Rob Herring
[not found] ` <CAL_Jsq+tkFNpjSEZboT+o69B_Z3a8e-ZVKaYDmLwtkyYoPy6VQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-05-30 19:49 ` Arnd Bergmann
2014-05-30 19:49 ` Arnd Bergmann
2014-05-30 19:49 ` Arnd Bergmann
2014-06-02 10:41 ` Dave Martin
2014-06-02 10:41 ` Dave Martin
2014-06-02 10:41 ` Dave Martin
[not found] ` <20140602104104.GD3855-M5GwZQ6tE7x5pKCnmE3YQBJ8xKzm50AiAL8bYrjMMd8@public.gmane.org>
2014-06-04 14:35 ` Thierry Reding
2014-06-04 14:35 ` Thierry Reding
2014-06-04 14:35 ` Thierry Reding
2014-06-04 16:41 ` Will Deacon
2014-06-04 16:41 ` Will Deacon
2014-06-04 16:41 ` Will Deacon
[not found] ` <20140604164132.GF6644-5wv7dgnIgG8@public.gmane.org>
2014-06-04 21:00 ` Thierry Reding
2014-06-04 21:00 ` Thierry Reding
2014-06-04 21:00 ` Thierry Reding
2014-06-05 19:10 ` Varun Sethi
2014-06-05 19:10 ` Varun Sethi
2014-06-05 19:10 ` Varun Sethi
2014-06-16 15:27 ` Will Deacon
2014-06-16 15:27 ` Will Deacon
2014-06-16 15:27 ` Will Deacon
[not found] ` <20140616152739.GS16758-5wv7dgnIgG8@public.gmane.org>
2014-06-16 16:56 ` Stuart Yoder
2014-06-16 16:56 ` Stuart Yoder
2014-06-16 16:56 ` Stuart Yoder
[not found] ` <8b0492b4697943a0b1f276ef42cc8223-ufbTtyGzTTT8GZusEWM6WuO6mTEJWrR4XA4E9RH9d+qIuWR1G4zioA@public.gmane.org>
2014-06-16 17:04 ` Will Deacon
2014-06-16 17:04 ` Will Deacon
2014-06-16 17:04 ` Will Deacon
[not found] ` <20140616170416.GA16758-5wv7dgnIgG8@public.gmane.org>
2014-06-16 17:30 ` Arnd Bergmann
2014-06-16 17:30 ` Arnd Bergmann
2014-06-16 17:30 ` Arnd Bergmann
2014-06-16 18:53 ` Stuart Yoder
2014-06-16 18:53 ` Stuart Yoder
2014-06-16 18:53 ` Stuart Yoder
[not found] ` <419e67f783524d208ab3be16bcd94bd9-ufbTtyGzTTT8GZusEWM6WuO6mTEJWrR4XA4E9RH9d+qIuWR1G4zioA@public.gmane.org>
2014-06-17 10:26 ` Varun Sethi
2014-06-17 10:26 ` Varun Sethi
2014-06-17 10:26 ` Varun Sethi
[not found] ` <0587e1f4894546398be0798d2bc2c84f-AZ66ij2kwaacCcN9WK45f+O6mTEJWrR4XA4E9RH9d+qIuWR1G4zioA@public.gmane.org>
2014-06-17 10:43 ` Will Deacon
2014-06-17 10:43 ` Will Deacon
2014-06-17 10:43 ` Will Deacon
[not found] ` <20140617104304.GD13808-5wv7dgnIgG8@public.gmane.org>
2014-06-17 11:21 ` Varun Sethi
2014-06-17 11:21 ` Varun Sethi
2014-06-17 11:21 ` Varun Sethi
[not found] ` <32165315f0b84be9948f489fd87bf6a9-AZ66ij2kwaacCcN9WK45f+O6mTEJWrR4XA4E9RH9d+qIuWR1G4zioA@public.gmane.org>
2014-06-17 14:50 ` Stuart Yoder
2014-06-17 14:50 ` Stuart Yoder
2014-06-17 14:50 ` Stuart Yoder
2014-06-18 9:29 ` Will Deacon [this message]
2014-06-18 9:29 ` Will Deacon
2014-06-18 9:29 ` Will Deacon
2014-06-17 14:39 ` Stuart Yoder
2014-06-17 14:39 ` Stuart Yoder
2014-06-17 14:39 ` Stuart Yoder
2014-06-20 23:16 ` Olav Haugan
2014-06-20 23:16 ` Olav Haugan
2014-06-20 23:16 ` Olav Haugan
2014-06-24 9:18 ` Will Deacon
2014-06-24 9:18 ` Will Deacon
2014-06-24 9:18 ` Will Deacon
[not found] ` <20140624091808.GC26013-5wv7dgnIgG8@public.gmane.org>
2014-06-24 17:57 ` Olav Haugan
2014-06-24 17:57 ` Olav Haugan
2014-06-24 17:57 ` Olav Haugan
2014-06-24 18:11 ` Will Deacon
2014-06-24 18:11 ` Will Deacon
2014-06-24 18:11 ` Will Deacon
[not found] ` <20140624181150.GB4067-5wv7dgnIgG8@public.gmane.org>
2014-06-24 18:20 ` Arnd Bergmann
2014-06-24 18:20 ` Arnd Bergmann
2014-06-24 18:20 ` Arnd Bergmann
2014-06-25 9:17 ` Will Deacon
2014-06-25 9:17 ` Will Deacon
2014-06-25 9:17 ` Will Deacon
2014-06-25 9:27 ` Arnd Bergmann
2014-06-25 9:27 ` Arnd Bergmann
2014-06-25 9:27 ` Arnd Bergmann
2014-06-25 9:38 ` Will Deacon
2014-06-25 9:38 ` Will Deacon
2014-06-25 9:38 ` Will Deacon
2014-06-25 9:48 ` Arnd Bergmann
2014-06-25 9:48 ` Arnd Bergmann
2014-06-25 9:48 ` Arnd Bergmann
2014-06-25 9:57 ` Will Deacon
2014-06-25 9:57 ` Will Deacon
2014-06-25 9:57 ` Will Deacon
[not found] ` <20140625095735.GI6153-5wv7dgnIgG8@public.gmane.org>
2014-06-25 10:12 ` Arnd Bergmann
2014-06-25 10:12 ` Arnd Bergmann
2014-06-25 10:12 ` Arnd Bergmann
2014-06-25 10:14 ` Will Deacon
2014-06-25 10:14 ` Will Deacon
2014-06-25 10:14 ` Will Deacon
2014-06-24 21:35 ` Olav Haugan
2014-06-24 21:35 ` Olav Haugan
2014-06-24 21:35 ` Olav Haugan
[not found] ` <53A9EF3A.2070704-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2014-06-25 9:18 ` Will Deacon
2014-06-25 9:18 ` Will Deacon
2014-06-25 9:18 ` Will Deacon
[not found] ` <20140625091858.GG6153-5wv7dgnIgG8@public.gmane.org>
2014-06-27 22:23 ` Olav Haugan
2014-06-27 22:23 ` Olav Haugan
2014-06-27 22:23 ` Olav Haugan
[not found] ` <53ADEEDF.7060902-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2014-06-30 9:52 ` Will Deacon
2014-06-30 9:52 ` Will Deacon
2014-06-30 9:52 ` Will Deacon
2014-07-09 1:07 ` Olav Haugan
2014-07-09 1:07 ` Olav Haugan
2014-07-09 1:07 ` Olav Haugan
[not found] ` <53BC95DA.1010500-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2014-07-09 10:54 ` Will Deacon
2014-07-09 10:54 ` Will Deacon
2014-07-09 10:54 ` Will Deacon
[not found] ` <20140709105441.GE9485-5wv7dgnIgG8@public.gmane.org>
2014-07-10 22:32 ` Olav Haugan
2014-07-10 22:32 ` Olav Haugan
2014-07-10 22:32 ` Olav Haugan
2014-07-11 12:24 ` Will Deacon
2014-07-11 12:24 ` Will Deacon
2014-07-11 12:24 ` Will Deacon
2014-05-23 20:36 Thierry Reding
2014-05-23 20:36 ` Thierry Reding
2014-05-23 20:36 ` Thierry Reding
[not found] ` <1400877395-4235-1-git-send-email-thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2014-05-29 15:52 ` Stephen Warren
2014-05-29 15:52 ` Stephen Warren
2014-05-29 15:52 ` Stephen Warren
2014-05-30 7:30 ` Thierry Reding
2014-05-30 7:30 ` Thierry Reding
2014-05-30 11:27 ` Dave Martin
2014-05-30 11:27 ` Dave Martin
2014-05-30 11:27 ` Dave Martin
[not found] ` <20140530112728.GB3949-M5GwZQ6tE7x5pKCnmE3YQBJ8xKzm50AiAL8bYrjMMd8@public.gmane.org>
2014-05-30 19:11 ` Arnd Bergmann
2014-05-30 19:11 ` Arnd Bergmann
2014-05-30 19:11 ` Arnd Bergmann
2014-06-02 10:56 ` Dave Martin
2014-06-02 10:56 ` Dave Martin
2014-06-02 10:56 ` Dave Martin
2014-06-04 21:12 ` Thierry Reding
2014-06-04 21:12 ` Thierry Reding
2014-06-04 21:12 ` Thierry Reding
2014-06-16 12:57 ` Will Deacon
2014-06-16 12:57 ` Will Deacon
2014-06-16 12:57 ` Will Deacon
2014-06-17 11:58 ` Thierry Reding
2014-06-17 11:58 ` Thierry Reding
2014-06-17 11:58 ` Thierry Reding
2014-06-17 12:18 ` Will Deacon
2014-06-17 12:18 ` Will Deacon
2014-06-17 12:18 ` Will Deacon
2014-06-17 23:37 ` Thierry Reding
2014-06-17 23:37 ` Thierry Reding
2014-06-17 23:37 ` Thierry Reding
2014-06-18 10:14 ` Will Deacon
2014-06-18 10:14 ` Will Deacon
2014-06-18 10:14 ` Will Deacon
[not found] ` <20140618101439.GF32699-5wv7dgnIgG8@public.gmane.org>
2014-06-20 15:53 ` Arnd Bergmann
2014-06-20 15:53 ` Arnd Bergmann
2014-06-20 15:53 ` Arnd Bergmann
2014-06-20 17:50 ` Will Deacon
2014-06-20 17:50 ` Will Deacon
2014-06-20 17:50 ` Will Deacon
2014-06-20 18:55 ` Arnd Bergmann
2014-06-20 18:55 ` Arnd Bergmann
2014-06-20 18:55 ` Arnd Bergmann
2014-05-30 11:22 ` Dave Martin
2014-05-30 11:22 ` Dave Martin
2014-05-30 11:22 ` Dave Martin
[not found] ` <20140530112226.GA3949-M5GwZQ6tE7x5pKCnmE3YQBJ8xKzm50AiAL8bYrjMMd8@public.gmane.org>
2014-05-30 19:01 ` Arnd Bergmann
2014-05-30 19:01 ` Arnd Bergmann
2014-05-30 19:01 ` Arnd Bergmann
2014-06-02 11:44 ` Dave Martin
2014-06-02 11:44 ` Dave Martin
2014-06-02 11:44 ` Dave Martin
2014-06-04 21:32 ` Thierry Reding
2014-06-04 21:32 ` Thierry Reding
2014-06-04 21:32 ` Thierry Reding
2014-06-05 9:42 ` Arnd Bergmann
2014-06-05 9:42 ` Arnd Bergmann
2014-06-05 9:42 ` Arnd Bergmann
2014-06-06 22:45 Thierry Reding
2014-06-06 22:45 ` Thierry Reding
2014-06-07 13:22 ` Arnd Bergmann
2014-06-07 13:22 ` Arnd Bergmann
2014-06-07 13:22 ` Arnd Bergmann
2014-06-09 10:49 ` Thierry Reding
2014-06-09 10:49 ` Thierry Reding
2014-06-09 10:49 ` Thierry Reding
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