From: hdoyu@nvidia•com (Hiroshi Doyu)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v12 11/31] documentation: iommu: add binding document of Exynos System MMU
Date: Tue, 29 Apr 2014 08:55:35 +0300 [thread overview]
Message-ID: <87eh0gd6i0.fsf@nvidia.com> (raw)
In-Reply-To: <20140428103919.GF19455@ulmo>
Thierry Reding <thierry.reding@gmail•com> writes:
> * PGP Signed by an unknown key
>
> On Sun, Apr 27, 2014 at 08:23:06PM +0200, Arnd Bergmann wrote:
>> On Sunday 27 April 2014 13:07:43 Shaik Ameer Basha wrote:
>> > +- mmu-masters: A phandle to device nodes representing the master for which
>> > + the System MMU can provide a translation. Any additional values
>> > + after the phandle will be ignored because a System MMU never
>> > + have two or more masters. "#stream-id-cells" specified in the
>> > + master's node will be also ignored.
>> > + If more than one phandle is specified, only the first phandle
>> > + will be treated.
>>
>> This seems completely backwards: Why would you list the masters for an IOMMU
>> in the IOMMU node?
>>
>> The master should have a standard property pointing to the IOMMU instead.
>>
>> We don't have a generic binding for IOMMUs yet it seems, but the time is
>> overdue to make one.
>>
>> Consider this NAKed until there is a generic binding for IOMMUs that all
>> relevant developers have agreed to.
>
> I'd like to take this opportunity and revive one of the hibernating
> patch sets that we have for Tegra. The last effort to get things merged
> was back in January I think. I haven't bothered to look up the reference
> since it's probably good to start from scratch anyway.
>
> The latest version of the binding that was under discussion back then I
> think looked something like this:
>
> device at ... {
> iommus = <&iommu [spec]>[, <&other_iommu [other_spec]>...];
> };
>
> And possibly with a iommu-names property to go along with that. The idea
> being that a device can be a master on possibly multiple IOMMUs. Using
> the above it would also be possible to have one device be multiple
> masters on the same IOMMU.
>
> On Tegra the specifier would be used to encode a memory controller's
> client ID. One discussion point back at the time was to encode the ID as
> a bitmask to allow more than a single master per entry. Another solution
> which I think is a little cleaner and more generic, would be to use one
> entry per master and use a single cell to encode the client ID. Devices
> with multiple clients to the same IOMMU could then use multiple entries
> referencing the same IOMMU.
>
> I've added Hiroshi Doyu on Cc since he knows the Tegra IOMMU best.
> Hiroshi, can you summarize exactly what the proposed bindings were. If
> my memory serves me well they were mostly along the lines of what Arnd
> proposes here, and perhaps they are something that can also be used for
> Exynos.
You can find the detail from:
[PATCHv7 09/12] iommu/tegra: smmu: get swgroups from DT "iommus="
http://lists.linuxfoundation.org/pipermail/iommu/2013-December/007212.html
You can specify any parameters which your iommu requires from a device,
and a device(master) can have multiple IOMMUs.
device at ... {
iommus = <&iommu [spec]>[, <&other_iommu [other_spec]>...];
};
next prev parent reply other threads:[~2014-04-29 5:55 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-27 7:37 [PATCH v12 00/31] iommu/exynos: Fixes and Enhancements of System MMU driver with DT Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 01/31] iommu/exynos: do not include removed header Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 02/31] iommu/exynos: add missing cache flush for removed page table entries Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 03/31] iommu/exynos: change error handling when page table update is failed Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 04/31] iommu/exynos: fix L2TLB invalidation Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 05/31] iommu/exynos: remove prefetch buffer setting Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 06/31] iommu/exynos: allocate lv2 page table from own slab Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 07/31] iommu/exynos: always enable runtime PM Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 08/31] iommu/exynos: handle one instance of sysmmu with a device descriptor Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 09/31] iommu/exynos: remove dbgname from drvdata of a System MMU Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 10/31] iommu/exynos: use managed device helper functions Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 11/31] documentation: iommu: add binding document of Exynos System MMU Shaik Ameer Basha
2014-04-27 18:23 ` Arnd Bergmann
2014-04-28 10:39 ` Thierry Reding
2014-04-28 10:56 ` Arnd Bergmann
2014-04-28 11:18 ` Thierry Reding
2014-04-28 12:05 ` Arnd Bergmann
2014-04-28 12:49 ` Thierry Reding
2014-04-28 19:30 ` Will Deacon
2014-04-28 19:55 ` Arnd Bergmann
2014-04-29 18:16 ` Dave Martin
2014-04-29 20:07 ` Grant Grundler
2014-04-29 21:00 ` Arnd Bergmann
2014-04-30 15:14 ` Dave Martin
2014-05-01 14:02 ` Cho KyongHo
2014-05-01 14:12 ` Arnd Bergmann
2014-05-01 14:50 ` Dave Martin
2014-05-01 17:41 ` Stephen Warren
2014-05-02 11:41 ` Dave Martin
2014-04-29 20:46 ` Arnd Bergmann
2014-05-01 11:15 ` Dave Martin
2014-05-01 13:29 ` Arnd Bergmann
2014-05-01 14:36 ` Dave Martin
2014-05-01 15:11 ` Marc Zyngier
2014-05-01 15:53 ` Arnd Bergmann
2014-05-01 16:24 ` Marc Zyngier
2014-05-01 15:46 ` Arnd Bergmann
2014-05-01 16:42 ` Grant Grundler
2014-05-15 20:37 ` Thierry Reding
2014-05-16 0:39 ` Cho KyongHo
2014-04-28 17:52 ` Stephen Warren
2014-04-29 5:55 ` Hiroshi Doyu [this message]
2014-04-27 7:37 ` [PATCH v12 12/31] iommu/exynos: support for device tree Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 13/31] iommu/exynos: gating clocks of master H/W Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 14/31] iommu/exynos: remove custom fault handler Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 15/31] iommu/exynos: handle 'mmu-masters' property of DT and improve handling sysmmu Shaik Ameer Basha
2014-04-27 18:17 ` Arnd Bergmann
2014-05-01 14:08 ` Cho KyongHo
2014-04-27 7:37 ` [PATCH v12 16/31] iommu/exynos: turn on useful configuration options Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 17/31] iommu/exynos: add support for power management subsystems Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 18/31] iommu/exynos: allow having multiple System MMUs for a master H/W Shaik Ameer Basha
2014-04-28 10:38 ` Tushar Behera
2014-05-01 14:10 ` Cho KyongHo
2014-05-06 18:05 ` Tomasz Figa
2014-05-09 10:54 ` Cho KyongHo
2014-04-27 7:37 ` [PATCH v12 19/31] iommu/exynos: change rwlock to spinlock Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 20/31] iommu/exynos: add devices attached to the System MMU to an IOMMU group Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 21/31] iommu/exynos: fix address handling Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 22/31] iommu/exynos: use exynos-iommu specific typedef Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 23/31] iommu/exynos: use simpler function to get MMU version Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 24/31] iommu/exynos: apply workaround of caching fault page table entries Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 25/31] iommu/exynos: enhanced error messages Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 26/31] clk: exynos: add gate clock descriptions of System MMU Shaik Ameer Basha
2014-04-27 7:37 ` [PATCH v12 27/31] ARM: dts: add System MMU nodes of exynos4 series Shaik Ameer Basha
2014-04-27 7:38 ` [PATCH v12 28/31] ARM: dts: add System MMU nodes of exynos4210 Shaik Ameer Basha
2014-04-27 7:38 ` [PATCH v12 29/31] ARM: dts: add System MMU nodes of exynos4x12 Shaik Ameer Basha
2014-04-27 7:38 ` [PATCH v12 30/31] ARM: dts: add System MMU nodes of exynos5250 Shaik Ameer Basha
2014-04-27 17:39 ` Vikas Sajjan
2014-04-28 23:13 ` Doug Anderson
2014-05-01 14:16 ` Cho KyongHo
2014-04-27 7:38 ` [PATCH v12 31/31] ARM: dts: add System MMU nodes of exynos5420 Shaik Ameer Basha
2014-04-28 8:34 ` [PATCH v12 00/31] iommu/exynos: Fixes and Enhancements of System MMU driver with DT Arnd Bergmann
2014-04-30 4:50 ` Shaik Ameer Basha
2014-04-30 10:57 ` Shaik Ameer Basha
2014-05-06 17:59 ` Joerg Roedel
2014-05-06 18:08 ` Tomasz Figa
2014-05-07 0:44 ` Cho KyongHo
2014-05-06 18:21 ` Arnd Bergmann
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