From: will.deacon@arm•com (Will Deacon)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC PATCH v3 5/7] dma-mapping: detect and configure IOMMU in of_dma_configure
Date: Mon, 22 Sep 2014 18:46:00 +0100 [thread overview]
Message-ID: <20140922174600.GJ7936@arm.com> (raw)
In-Reply-To: <4252161.sBJZLIS2WH@avalon>
On Thu, Sep 18, 2014 at 12:17:33PM +0100, Laurent Pinchart wrote:
> Hi Will,
Hello again,
> On Friday 12 September 2014 17:34:53 Will Deacon wrote:
> > @@ -195,7 +197,19 @@ static void of_dma_configure(struct platform_device
> > *pdev) dev_dbg(dev, "device is%sdma coherent\n",
> > coherent ? " " : " not ");
> >
> > - arch_setup_dma_ops(dev, coherent);
> > + iommu = of_iommu_configure(dev);
> > + dev_dbg(dev, "device is%sbehind an iommu\n",
> > + iommu ? " " : " not ");
> > +
> > + arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
> > +
> > + if (iommu)
> > + kref_put(&iommu->kref, of_iommu_deconfigure);
>
> What's the expected life cycle of the iommu_dma_mapping structure ? It gets
> created by of_iommu_configure() and the initial reference gets dropped here. I
> suppose you expect arch code to need to keep a reference to the structure, but
> your implementation in patch 7/7 doesn't. As far as I can see, you don't even
> use the contents of the structure in the ARM arch_setup_dma_ops()
> implementation. Do you expect that to change later, or other architectures to
> need it ?
Indeed, I've not done anything to the ARM dma-mapping ops other than plug-in
the existing code, which doesn't use these new features. I think Marek was
going to look at that.
> By the way, now that I think about it, I find struct iommu_dma_mapping and
> struct dma_iommu_mapping very confusing.
Yup; I'd like to see some generic code that uses the per-IOMMU-instance
domain and allocator which is passed to arch_setup_dma_ops. Then we could
simply move arch/arm/ (and arm64) over to that, which would get rid of
dma_iommu_mapping entirely.
Will
next prev parent reply other threads:[~2014-09-22 17:46 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-12 16:34 [RFC PATCH v3 0/7] Introduce automatic DMA configuration for IOMMU masters Will Deacon
2014-09-12 16:34 ` [RFC PATCH v3 1/7] iommu: provide early initialisation hook for IOMMU drivers Will Deacon
2014-09-18 14:31 ` Robin Murphy
2014-09-22 17:35 ` Will Deacon
2014-09-12 16:34 ` [RFC PATCH v3 2/7] dma-mapping: replace set_arch_dma_coherent_ops with arch_setup_dma_ops Will Deacon
2014-09-12 16:34 ` [RFC PATCH v3 3/7] iommu: add new iommu_ops callback for adding an OF device Will Deacon
2014-09-15 11:57 ` Marek Szyprowski
2014-09-17 1:39 ` Will Deacon
2014-09-12 16:34 ` [RFC PATCH v3 4/7] iommu: provide helper function to configure an IOMMU for an of master Will Deacon
2014-09-18 11:13 ` Laurent Pinchart
2014-09-22 17:13 ` Will Deacon
2014-10-14 13:12 ` Laurent Pinchart
2014-09-12 16:34 ` [RFC PATCH v3 5/7] dma-mapping: detect and configure IOMMU in of_dma_configure Will Deacon
2014-09-18 11:17 ` Laurent Pinchart
2014-09-22 9:29 ` Thierry Reding
2014-09-22 17:50 ` Will Deacon
2014-10-14 12:53 ` Laurent Pinchart
2014-10-27 10:51 ` Will Deacon
2014-10-27 11:12 ` Marek Szyprowski
2014-10-27 11:30 ` Laurent Pinchart
2014-10-27 16:02 ` Will Deacon
2014-10-27 16:33 ` jroedel at suse.de
2014-09-22 17:46 ` Will Deacon [this message]
2014-09-12 16:34 ` [RFC PATCH v3 6/7] arm: call iommu_init before of_platform_populate Will Deacon
2014-09-22 9:36 ` Thierry Reding
2014-09-22 11:08 ` Arnd Bergmann
2014-09-22 11:40 ` Thierry Reding
2014-09-22 16:03 ` Arnd Bergmann
2014-09-23 7:02 ` Thierry Reding
2014-09-23 7:44 ` Arnd Bergmann
2014-09-23 8:59 ` Thierry Reding
2014-10-14 13:07 ` Laurent Pinchart
2014-10-14 13:20 ` Arnd Bergmann
2014-10-14 13:37 ` Thierry Reding
2014-10-14 15:01 ` Laurent Pinchart
2014-10-14 15:05 ` Thierry Reding
2014-10-14 15:10 ` Laurent Pinchart
2014-09-12 16:34 ` [RFC PATCH v3 7/7] arm: dma-mapping: plumb our iommu mapping ops into arch_setup_dma_ops Will Deacon
2014-09-22 9:19 ` Thierry Reding
2014-09-22 9:22 ` Laurent Pinchart
2014-09-22 17:43 ` Will Deacon
2014-09-23 7:14 ` Thierry Reding
2014-09-24 16:33 ` Will Deacon
2014-09-25 6:40 ` Thierry Reding
2014-09-30 16:00 ` Will Deacon
2014-10-01 8:46 ` Thierry Reding
2014-10-03 15:08 ` Will Deacon
2014-10-06 9:52 ` Thierry Reding
2014-10-06 10:50 ` Laurent Pinchart
2014-10-06 13:05 ` Thierry Reding
2014-09-16 11:40 ` [RFC PATCH v3 0/7] Introduce automatic DMA configuration for IOMMU masters Robin Murphy
2014-09-17 1:19 ` Will Deacon
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