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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 C7F97C3815B for ; Mon, 20 Apr 2020 18:11:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A4C2A2074F for ; Mon, 20 Apr 2020 18:11:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="RQB1iEKR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727846AbgDTSLB (ORCPT ); Mon, 20 Apr 2020 14:11:01 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:37876 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726316AbgDTSLB (ORCPT ); Mon, 20 Apr 2020 14:11:01 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1587406261; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=wos3Ak73xOXHzWR83+yksTYRpe5mwIS/buxq9eAwCz8=; b=RQB1iEKRGcSu218jO4hi+FgvLOLmZKLvZKC5tL2RxE9MzdKkD/tmFVqKfPcPtH4Y74i7RiCq HZRuLGW4yffItJy7rFirdWhT2hU8z9HfY+IhfeKk0bCKCHnpoZFyL0ODqy2PQFNjM/6RsVWC xMoSklDcRGIMv/2VaBrUDZIONTE= X-Mailgun-Sending-Ip: 104.130.122.27 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5e9de5a5.7f8e56643570-smtp-out-n04; Mon, 20 Apr 2020 18:10:45 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id DB666C433F2; Mon, 20 Apr 2020 18:10:43 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: saiprakash.ranjan) by smtp.codeaurora.org (Postfix) with ESMTPSA id 5DCECC433D2; Mon, 20 Apr 2020 18:10:42 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 20 Apr 2020 23:40:42 +0530 From: Sai Prakash Ranjan To: Robin Murphy Cc: Will Deacon , Joerg Roedel , Sibi Sankar , Bjorn Andersson , Jordan Crouse , Rob Clark , Stephen Boyd , iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Matthias Kaehlcke , Evan Green Subject: Re: [PATCHv3 4/6] iommu/arm-smmu-qcom: Request direct mapping for modem device In-Reply-To: <49c8c377-961b-3f95-a99c-08528def4cb7@arm.com> References: <509d88fbe7592aa15f867933c177b61bc7ba8efa.1587400573.git.saiprakash.ranjan@codeaurora.org> <49c8c377-961b-3f95-a99c-08528def4cb7@arm.com> Message-ID: <98fa2940456ade2bd0998dfaa6386653@codeaurora.org> X-Sender: saiprakash.ranjan@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Robin, On 2020-04-20 22:39, Robin Murphy wrote: > On 2020-04-20 5:42 pm, Sai Prakash Ranjan wrote: >> From: Sibi Sankar >> >> Request direct mapping for modem on platforms which don't have >> TrustZone >> (which programs the modem SIDs) to prevent the following global faults >> seen >> on Cheza/Trogdor: > > Not strictly true - it's patch #6/6 that prevents *those* faults (and > these days the driver should be reporting unmatched streams a little > more helpfully). This change would resolve the context faults and/or > weird memory corruption that might result from applying patch #6 alone > - this is the crazy thing where transactions sometimes go directly to > DRAM round the side of the SMMU so we can never safely remap anything, > right? > True this doesnt prevent global faults, the fault details should go to patch6. I'll update the commit msg something like below: The Q6 modem sub-system has direct access to DDR through memnoc. Also SMMU is not expected to provide access control/translation for these SIDs (sandboxing of the modem is achieved through XPUs engaged using SMC calls). Thanks, Sai -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation