From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mitchel Humpherys Subject: Re: [PATCH 0/3] Add support for privileged mappings Date: Fri, 08 Jul 2016 19:09:13 -0700 Message-ID: References: <20160706235136.27854-1-mitchelh@codeaurora.org> <20160707170026.GG20682@arm.com> <20160707205820.GA752@jcrouse-lnx.qualcomm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160707205820.GA752-9PYrDHPZ2Orvke4nUoYGnHL1okKdlPRT@public.gmane.org> (Jordan Crouse's message of "Thu, 7 Jul 2016 14:58:21 -0600") 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: Jordan Crouse Cc: Patrick Daly , Jeremy Gebben , Will Deacon , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Pratik Patel List-Id: iommu@lists.linux-foundation.org On Thu, Jul 07 2016 at 02:58:21 PM, Jordan Crouse wrote: >> Whilst this series is a step in the right direction for fixing that, I >> don't think you can claim that only low-level users need this, given that >> we have in-tree code which would break without it. Perhaps you just need >> to extend things slightly more to expose this to the DMA API as well (or, >> alternatively, hack the PL330 driver some how). > > I agree that hacking the DMA api would be the best long term solution but there > be dragons there. Perhaps a workable compromise might be to white-list > privileged aware devices via the device tree. I'm sending a v2 with an attempt at plumbing this through the DMA layer. Hopefully avoiding dragons while I'm at it :) -Mitch -- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project From mboxrd@z Thu Jan 1 00:00:00 1970 From: mitchelh@codeaurora.org (Mitchel Humpherys) Date: Fri, 08 Jul 2016 19:09:13 -0700 Subject: [PATCH 0/3] Add support for privileged mappings In-Reply-To: <20160707205820.GA752@jcrouse-lnx.qualcomm.com> (Jordan Crouse's message of "Thu, 7 Jul 2016 14:58:21 -0600") References: <20160706235136.27854-1-mitchelh@codeaurora.org> <20160707170026.GG20682@arm.com> <20160707205820.GA752@jcrouse-lnx.qualcomm.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jul 07 2016 at 02:58:21 PM, Jordan Crouse wrote: >> Whilst this series is a step in the right direction for fixing that, I >> don't think you can claim that only low-level users need this, given that >> we have in-tree code which would break without it. Perhaps you just need >> to extend things slightly more to expose this to the DMA API as well (or, >> alternatively, hack the PL330 driver some how). > > I agree that hacking the DMA api would be the best long term solution but there > be dragons there. Perhaps a workable compromise might be to white-list > privileged aware devices via the device tree. I'm sending a v2 with an attempt at plumbing this through the DMA layer. Hopefully avoiding dragons while I'm at it :) -Mitch -- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project