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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 4B28EC4BA11 for ; Wed, 26 Feb 2020 08:45:15 +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 222F2206E6 for ; Wed, 26 Feb 2020 08:45:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ENoq3vxz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 222F2206E6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.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=j5BC7KllhQGu5wt0RvM41HNhytXmstVbnQkKlGTgrT8=; b=ENoq3vxzoENUEzgG4MHSEKtGa rfQiu7QqGOg76h8Z9ZuYbhAYZT+clW1b1RIUICa1uF0Cl22qtPrhlIU+8PA/SpRcVc+DTtm5GsnM3 GLeD2Zq/zNBprSSz0dNKp1DGTgwo7eQGfi/jZnqvr/4h/Dr1f2zSuReKEbzIGYbZbCNkmXFVJvc8B ZFL1VW7xuTVKkIlLwRtvPuNs9jofCjkSXZ+cXSfTUeNiNFVIf6OeqeX5vLnBr6f6ouM2/Qc5hOIad siAOX/+GKw3d4MSst7GWMNGUMpd7tZwKwT++xUhzchWt7qpPDhzzfhu097k0nzfNmDuveR5YWx5St DBZOscNfA==; 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 1j6sJW-0005eR-DB; Wed, 26 Feb 2020 08:45:06 +0000 Received: from szxga07-in.huawei.com ([45.249.212.35] helo=huawei.com) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6sJT-0005Dx-0r for linux-arm-kernel@lists.infradead.org; Wed, 26 Feb 2020 08:45:04 +0000 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 730B97C1AE6C45ED5204; Wed, 26 Feb 2020 16:44:54 +0800 (CST) Received: from [127.0.0.1] (10.67.101.242) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.439.0; Wed, 26 Feb 2020 16:44:53 +0800 Subject: Re: [PATCH v4 23/26] iommu/arm-smmu-v3: Add stall support for platform devices To: Jean-Philippe Brucker , , , , , References: <20200224182401.353359-1-jean-philippe@linaro.org> <20200224182401.353359-24-jean-philippe@linaro.org> From: Xu Zaibo Message-ID: Date: Wed, 26 Feb 2020 16:44:53 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <20200224182401.353359-24-jean-philippe@linaro.org> X-Originating-IP: [10.67.101.242] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200226_004503_251145_F8D30B54 X-CRM114-Status: GOOD ( 18.83 ) 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: mark.rutland@arm.com, kevin.tian@intel.com, will@kernel.org, Jean-Philippe Brucker , catalin.marinas@arm.com, robh+dt@kernel.org, zhangfei.gao@linaro.org, robin.murphy@arm.com, christian.koenig@amd.com 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 Hi, On 2020/2/25 2:23, Jean-Philippe Brucker wrote: > From: Jean-Philippe Brucker > > The SMMU provides a Stall model for handling page faults in platform > devices. It is similar to PCI PRI, but doesn't require devices to have > their own translation cache. Instead, faulting transactions are parked and > the OS is given a chance to fix the page tables and retry the transaction. > > Enable stall for devices that support it (opt-in by firmware). When an > event corresponds to a translation error, call the IOMMU fault handler. If > the fault is recoverable, it will call us back to terminate or continue > the stall. > > Signed-off-by: Jean-Philippe Brucker > --- > drivers/iommu/arm-smmu-v3.c | 271 ++++++++++++++++++++++++++++++++++-- > drivers/iommu/of_iommu.c | 5 +- > include/linux/iommu.h | 2 + > 3 files changed, 269 insertions(+), 9 deletions(-) > > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > index 6a5987cce03f..da5dda5ba26a 100644 > --- a/drivers/iommu/arm-smmu-v3.c > +++ b/drivers/iommu/arm-smmu-v3.c > @@ -374,6 +374,13 @@ > #define CMDQ_PRI_1_GRPID GENMASK_ULL(8, 0) > #define CMDQ_PRI_1_RESP GENMASK_ULL(13, 12) > [...] > +static int arm_smmu_page_response(struct device *dev, > + struct iommu_fault_event *unused, > + struct iommu_page_response *resp) > +{ > + struct arm_smmu_cmdq_ent cmd = {0}; > + struct arm_smmu_master *master = dev_iommu_fwspec_get(dev)->iommu_priv; Here can use 'dev_to_master' ? Cheers, Zaibo . > + int sid = master->streams[0].id; > + > + if (master->stall_enabled) { > + cmd.opcode = CMDQ_OP_RESUME; > + cmd.resume.sid = sid; > + cmd.resume.stag = resp->grpid; > + switch (resp->code) { > + case IOMMU_PAGE_RESP_INVALID: > + case IOMMU_PAGE_RESP_FAILURE: > + cmd.resume.resp = CMDQ_RESUME_0_RESP_ABORT; > + break; > + case IOMMU_PAGE_RESP_SUCCESS: > + cmd.resume.resp = CMDQ_RESUME_0_RESP_RETRY; > + break; > + default: > + return -EINVAL; > + } > + } else { > + /* TODO: insert PRI response here */ > + return -ENODEV; > + } > + > + arm_smmu_cmdq_issue_cmd(master->smmu, &cmd); > + /* > + * Don't send a SYNC, it doesn't do anything for RESUME or PRI_RESP. > + * RESUME consumption guarantees that the stalled transaction will be > + * terminated... at some point in the future. PRI_RESP is fire and > + * forget. > + */ > + > + return 0; > +} > + [...] _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel