Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752362AbaBXR3E (ORCPT ); Mon, 24 Feb 2014 12:29:04 -0500 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:38510 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752240AbaBXR3B (ORCPT ); Mon, 24 Feb 2014 12:29:01 -0500 Date: Mon, 24 Feb 2014 17:28:50 +0000 From: Will Deacon To: srikanth TS Cc: "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , "ts.srikanth@samsung.com" , "sungjinn.chung@samsung.com" Subject: Re: your mail Message-ID: <20140224172850.GG2553@mudshark.cambridge.arm.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. (2) Describe the RID -> SID mapping in the device-tree. We probably want to avoid an enormous table, so this would only work for simple `SID = RID + offset' or 'SID = RID & mask' cases. How do your IDs map to each other? Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/