From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: your mail Date: Tue, 25 Feb 2014 15:01:25 +0000 Message-ID: <20140225150125.GC23136@mudshark.cambridge.arm.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: srikanth TS Cc: "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , "sungjinn.chung-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "ts.srikanth-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org" List-Id: iommu@lists.linux-foundation.org On Tue, Feb 25, 2014 at 11:20:11AM +0000, srikanth TS wrote: > > On Feb 25, 2014 2:28 AM, "Will Deacon" > wrote: > > > > 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. > > I think first way of solving seems to be better, because we don't know how many > > VF are used and i feel its not good idea to keep whole list of streamID [which is > > equal to max num vf] in DT. Again in this method we need to generate the stream ID > > dynamically whenever VF is added in pci iov driver side. And then pass that > > stream ID to SMMU. > > Is it ok this way? Or you prefer 2nd way which is simpler. I'm happy either way, but I'd need to see some patches before I can merge anything ;) Will