On 01/29/2015 07:24 PM, Laurent Pinchart wrote:
Hi Rob,
On Thursday 29 January 2015 10:49:38 Rob Herring wrote:
On Wed, Jan 28, 2015 at 5:32 PM, Laurent Pinchart wrote:
On Wednesday 28 January 2015 13:32:19 Will Deacon wrote:
On Wed, Jan 28, 2015 at 01:15:10PM +0000, Laurent Pinchart wrote:
On Wednesday 28 January 2015 12:29:42 Will Deacon wrote:
On Wed, Jan 28, 2015 at 12:23:03PM +0000, Laurent Pinchart wrote:
On Wednesday 28 January 2015 11:33:00 Will Deacon wrote:
On Mon, Jan 26, 2015 at 06:49:01PM +0000, Murali Karicheri wrote:
On 01/25/2015 08:32 AM, Laurent Pinchart wrote:
On Friday 23 January 2015 17:32:34 Murali Karicheri wrote:
Function of_iommu_configure() is called from of_dma_configure()
to setup iommu ops using DT property. This API is currently used
for platform devices for which DMA configuration (including iommu
ops) may come from device's parent. To extend this functionality
for PCI devices, this API need to take a parent node ptr as an
argument instead of assuming device's parent. This is needed since
for PCI, the dma configuration may be defined in the DT node of
the root bus bridge's parent device. Currently only dma-range is
used for PCI and iommu is not supported. So return error if the
device is PCI.
[...]
If I understand Murali's patch set right (please correct me if that's
not the case) the PCI code walks up the DT nodes hierarchy to the
parent node that contains the iommus attribute and passes a pointer to
that node to this function. It's thus a PCI-specific solution. As a
temporary hack that's OK I suppose, but if implementing it right
straight away isn't difficult that would be better.
It looks to me like the code walks the PCI topology to get the DT node
for the host controller, and passes *that* to of_dma_configure. That
sounds like the right thing to do to me, especially since the PCI
topology is likely not encoded in the device-tree. So actually, it is
passing the first parent node afaict.
Indeed, that's right. I forgot for a moment that we have non-DT devices
;-)
Acked-by: Laurent Pinchart<laurent.pinchart@xxxxxxxxxxxxxxxx>
Murali, nitpicking a bit, shouldn't the iommu_np parameter be renamed ? It
points to the node containing the iommus parameter, not to the iommu node,
so the current name is slightly confusing. A brief kerneldoc above the
function would also help. This can be the subject of a separate patch.
It was more confusing having np and node within the function.
Agreed.
How about master_np or iommu_master_np ? The latter might be a bit long.
Probabaly master_np suffice as this function is named
of_iommu_configure(). I will update it.
--
Murali Karicheri
Linux Kernel, Texas Instruments
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