From: Will Deacon <will.deacon@arm.com>
To: Varun Sethi <Varun.Sethi@freescale.com>
Cc: Thierry Reding <thierry.reding@gmail.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>,
Pawel Moll <Pawel.Moll@arm.com>, Arnd Bergmann <arnd@arndb.de>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Grant Grundler <grundler@chromium.org>,
Stephen Warren <swarren@wwwdotorg.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Marc Zyngier <Marc.Zyngier@arm.com>,
Linux IOMMU <iommu@lists.linux-foundation.org>,
Rob Herring <robh+dt@kernel.org>,
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>,
Stuart Yoder <stuart.yoder@freescale.com>
Subject: Re: [PATCH v2] devicetree: Add generic IOMMU device tree bindings
Date: Mon, 16 Jun 2014 16:27:39 +0100 [thread overview]
Message-ID: <20140616152739.GS16758@arm.com> (raw)
In-Reply-To: <07321368d15d4ad9928ebb83af87e401@DM2PR03MB479.namprd03.prod.outlook.com>
Hi Varun,
On Thu, Jun 05, 2014 at 08:10:19PM +0100, Varun Sethi wrote:
> > The set of StreamIDs that can be generated by a master is fixed in the
> > hardware. The SMMU can then be programmed to map these incoming IDs onto
> > a context ID (or a set of context IDs), which are the IDs used internally
> > by the SMMU to find the page tables etc.
> >
> > The StreamID -> ContextID mapping is dynamic and controlled by software.
> > The Master -> StreamIDs mapping is fixed in the hardware.
> The Master -> StreamIDs mapping may not always be fixed in the hardware.
> At, least in our case we plan to program these via software. PCI devices
> is one place where this mapping would have to be dynamic (based on the
> topology i.e. if the devices are connected to a bridge etc). Also, we have
> a hot plug device architecture where the stream ID is software
> programmable.
>
> Other than that, based on the isolation requirements (iommu domain)
> software programmability offers greater flexibility.
For the sake of consistency, I'd really like to treat the master ->
streamIDs mapping as fixed. If that means setting it once during boot in
your case, then so be it (ideally in the firmware). That way, we just
describe the fixed mapping to the kernel and the driver doesn't have to
worry about changing the mapping, especially given that that's likely to be
highly error-prone once the SMMU is in us.
Do you have use-cases where you really need to change these mappings
dynamically?
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: Mon, 16 Jun 2014 16:27:39 +0100 [thread overview]
Message-ID: <20140616152739.GS16758@arm.com> (raw)
In-Reply-To: <07321368d15d4ad9928ebb83af87e401@DM2PR03MB479.namprd03.prod.outlook.com>
Hi Varun,
On Thu, Jun 05, 2014 at 08:10:19PM +0100, Varun Sethi wrote:
> > The set of StreamIDs that can be generated by a master is fixed in the
> > hardware. The SMMU can then be programmed to map these incoming IDs onto
> > a context ID (or a set of context IDs), which are the IDs used internally
> > by the SMMU to find the page tables etc.
> >
> > The StreamID -> ContextID mapping is dynamic and controlled by software.
> > The Master -> StreamIDs mapping is fixed in the hardware.
> The Master -> StreamIDs mapping may not always be fixed in the hardware.
> At, least in our case we plan to program these via software. PCI devices
> is one place where this mapping would have to be dynamic (based on the
> topology i.e. if the devices are connected to a bridge etc). Also, we have
> a hot plug device architecture where the stream ID is software
> programmable.
>
> Other than that, based on the isolation requirements (iommu domain)
> software programmability offers greater flexibility.
For the sake of consistency, I'd really like to treat the master ->
streamIDs mapping as fixed. If that means setting it once during boot in
your case, then so be it (ideally in the firmware). That way, we just
describe the fixed mapping to the kernel and the driver doesn't have to
worry about changing the mapping, especially given that that's likely to be
highly error-prone once the SMMU is in us.
Do you have use-cases where you really need to change these mappings
dynamically?
Will
next prev parent reply other threads:[~2014-06-16 15:27 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 [this message]
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
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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