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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 1BC0AC38A24 for ; Thu, 7 May 2020 14:56:39 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DC1AB20736 for ; Thu, 7 May 2020 14:56:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="QAIlTmRC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DC1AB20736 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+Pe9/59ilGOCh1Gz6fmKnkr39s9QDlQcbUbO0i4YWyg=; b=QAIlTmRCX1A7Ai0uP5EszYZ9F WlR/3CqEUgiYJgFd2s4pY6KoVNxif1mMlN9mqukNnWCh2Cx94Bv2K5pRf0OFTEH78MoNSy+Ef3wk7 L73E7e+uBev/Az+E9JU1WV61jvu7WxYnZS0R0+RW58GIHXNaGcJBDhkOFQFbci1pOlA+xN1K0n1T9 3hhqptieF00BLiAHRoFxzbloo7yf56c7euzoW+zW7B8aORNWR6Ipb5Dot9D9+Kq4WBOORbai6xbMT x8NSExDE0ErI2UBTmV1BsVV6tPJ4sF899HBi18ksH7AMGyVg14n6WpbJiXL55ZpKZ7zkmIzFHTqiw E4vk5PdDQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWhwv-00089y-Mf; Thu, 07 May 2020 14:56:33 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWhwt-00089b-LV for linux-arm-kernel@lists.infradead.org; Thu, 07 May 2020 14:56:32 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 75A1C1FB; Thu, 7 May 2020 07:56:30 -0700 (PDT) Received: from [10.57.36.85] (unknown [10.57.36.85]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1D63D3F68F; Thu, 7 May 2020 07:56:28 -0700 (PDT) Subject: Re: [PATCH] iomm/arm-smmu: Add stall implementation hook To: Sai Prakash Ranjan , Rob Clark References: <20200421202004.11686-1-saiprakash.ranjan@codeaurora.org> <1ced023b-157c-21a0-ac75-1adef7f029f0@arm.com> From: Robin Murphy Message-ID: <80a3b07d-f3a7-07c4-4e8f-76e28563027c@arm.com> Date: Thu, 7 May 2020 15:56:28 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200507_075631_746075_D5C72F03 X-CRM114-Status: GOOD ( 14.24 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arm-msm@vger.kernel.org, Joerg Roedel , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Jordan Crouse , Will Deacon , linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2020-05-07 1:06 pm, Sai Prakash Ranjan wrote: [...] > We could have our own context fault handler in QCOM implementation, > but that would just be duplicating things from arm-smmu context fault > handler. So I did not think it makes much sense to have our own > fault handler in qcom impl just for enabling stall model. Hmm, it's probably worth thinking ahead a bit here, to the "actually doing things with stalls" plan. I don't have a clear picture off-hand of how well the new device fault handler API might fit into arm-smmu - at the very least trying to make it truly generic implies having to play nasty tricks with disable_irq() for the general case given the "IRQ may remain asserted while SS is active" possibility, and that isn't particularly inviting. Not to mention tying it into the pretend-auxdomain stuff that *is* rather dependent on the qcom impl. If it turns out that you'll eventually have to reimplement the IRQ handler anyway for all that, then starting off down that route *might* work out cleaner and less hassle overall. Robin. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel