RE: your mail

Varun Sethi
2014-02-25T11:28:55Z

> -----Original Message-----
> From: iommu-bounces@lists.linux-foundation.org [mailto:iommu-
> bounces@lists.linux-foundation.org] On Behalf Of Will Deacon
> Sent: Monday, February 24, 2014 10:59 PM
> To: srikanth TS
> Cc: iommu@lists.linux-foundation.org; sungjinn.chung@samsung.com; linux-
> kernel@vger.kernel.org; ts.srikanth@samsung.com
> Subject: Re: your mail
>
> On Mon, Feb 24, 2014 at 03:12:21PM +0000, srikanth TS wrote:
> > Hi Will Deacon,
>
> Hello,
>
> > Currently SMMU driver expecting all stream ID used by respective
> > master should be defined in the DT.
> >
> > We want to know how to handle in the case of virtual functions
> > dynamically created and destroyed.
> >
> > Is PCI driver responsible for creating stream ID respective BDand
> > requesting SMMU to add to the mapping table[stream Id to context
> > mapping table]?
> >
> > Or is there any right way of doing it?
>
> Correct, the driver currently doesn't support dynamic mappings (mainly
> because I didn't want to try and invent something that I couldn't test).
>
> There are a couple of ways to solve this:
>
> (1) Add a way for a PCI RC to dynamically allocate StreamIDs on an SMMU
> within a fixed range. That would probably need some code in the bus
> layer, so that a bus notifier can kick and call back to the
> relevant
> SMMU.
This could be done in add device notifier. I am working on similar(not PCI) hot plug device infrastructure for arm smmu driver. I will post an RFC patch by next week.

-Varun