From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46CE2C18E5B for ; Tue, 10 Mar 2020 16:23:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 20A5521D56 for ; Tue, 10 Mar 2020 16:23:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726757AbgCJQXY (ORCPT ); Tue, 10 Mar 2020 12:23:24 -0400 Received: from 8bytes.org ([81.169.241.247]:50882 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726488AbgCJQXY (ORCPT ); Tue, 10 Mar 2020 12:23:24 -0400 Received: by theia.8bytes.org (Postfix, from userid 1000) id BF8F2396; Tue, 10 Mar 2020 17:23:21 +0100 (CET) Date: Tue, 10 Mar 2020 17:23:20 +0100 From: Joerg Roedel To: Sibi Sankar Cc: bjorn.andersson@linaro.org, robh+dt@kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org, iommu@lists.linux-foundation.org, linux-remoteproc@vger.kernel.org, ohad@wizery.com, agross@kernel.org, linux-kernel-owner@vger.kernel.org Subject: Re: [PATCH 0/3] Request direct mapping for modem firmware subdevice Message-ID: <20200310162320.GL3794@8bytes.org> References: <20200309182255.20142-1-sibis@codeaurora.org> <20200310112332.GG3794@8bytes.org> <4ed6ddd667a3e6f670084a443d141474@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4ed6ddd667a3e6f670084a443d141474@codeaurora.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 10, 2020 at 07:30:50PM +0530, Sibi Sankar wrote: > The accesses are initiated by the firmware > and they access modem reserved regions. > However as explained in ^^ any accesses > outside the region will result in a violation > and is controlled through XPUs (protection units). Okay, this sounds like a case for arm_smmu_get_resv_region(). It should return an entry for the reserved memory region the firmware needs to access, so that generic iommu can setup this mapping. Note that it should return that entry only for your device, not for all devices. Maybe there is a property in DT or IORT you can set to transport this information into the arm-smmu driver. This is pretty similar to RMRR mapping on the Intel VT-d IOMMU or Unity-mapped ranges in the AMD-Vi IOMMU. Regards, Joerg