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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 B51B7C3F68F for ; Wed, 18 Dec 2019 16:13:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A4862176D for ; Wed, 18 Dec 2019 16:13:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="TO3udsaM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727031AbfLRQNd (ORCPT ); Wed, 18 Dec 2019 11:13:33 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:39083 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727021AbfLRQNc (ORCPT ); Wed, 18 Dec 2019 11:13:32 -0500 Received: by mail-wr1-f65.google.com with SMTP id y11so2918761wrt.6 for ; Wed, 18 Dec 2019 08:13:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=PXvdq6qWFeAmRkgUP6ivkMlcnTIDIWAWnzZnITD9gIQ=; b=TO3udsaM0wHSFHtqq3lx9Vpw/cuxpABpx0ZL6fQor8a23g56txPXE2jNc4FuScZ3Fi LXZKSp/98TUo9nRfA1Ld8V1forbku0Bk8tJ7SeCtxPlk3DYZ/BK9L2TwV3xh0U+J3QHt JSei+y68UXeLCYVSEiEOrmRm+hf9jKrLSy3waZ06SVfY3S32E4pocftRNi7yO6SsbTOE unPpzZIPwL0bn7imVjhmGKGqJ7kxahOEYFOwX2CzXvusbd5u0aHn0r4+JtE8EWQKZb4G tXYPPjKJCaNiGfLjAylBAAaSiaK44cjKb9WiZ+3GgVPYjq+oQZQM5pfgoyCaaxXTBT4G e4hA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=PXvdq6qWFeAmRkgUP6ivkMlcnTIDIWAWnzZnITD9gIQ=; b=V/s9DEVJqRzMLZW0H9haErg8GRmUwvKhAGBUELDlQo0hkB21sUP2rrBVe450QmCDDs ovD0JelfRYKc4h4NIerpvLT0i1EUx9qkvBOancFQb3nOJIij3Aw6Sw6Kcsr6ZBh5vK65 b8zCqmHccB/H12bYL3XrvzlrIU9JBl0nJuv9vARiljyDc1z9WGS0lqsMlSBqGNIi6gNH mo9yO6TDeoUfMHFBPVPtb8ssqhCJTFaei5pwNFzoIH2xS2ma4kuxG127VGWOHShBv2gU IHkkwdPxXMGelyYVQ65ZxDOvegTXK5RSQM7e7YheeMH29yYi24qx+f2iGjSpV918+PaN 6+UQ== X-Gm-Message-State: APjAAAU5ORJdgGOUrzznwbQ/rFFuvSuucBlN5p+EX8zeQTAT+vJbtRyO 2H2B09ZNYVnvWPlGKlxLL3imkg== X-Google-Smtp-Source: APXvYqz3/O6xngUMvfQZDBfpU617F1qkmNRS56a4TzmWh1A2QPAdGPRnlUyBsXlERsvvTcYDCOXcBA== X-Received: by 2002:adf:f244:: with SMTP id b4mr3692481wrp.88.1576685610515; Wed, 18 Dec 2019 08:13:30 -0800 (PST) Received: from myrica (adsl-84-227-176-239.adslplus.ch. [84.227.176.239]) by smtp.gmail.com with ESMTPSA id b17sm3034639wrp.49.2019.12.18.08.13.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Dec 2019 08:13:29 -0800 (PST) Date: Wed, 18 Dec 2019 17:13:23 +0100 From: Jean-Philippe Brucker To: Auger Eric Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, devicetree@vger.kernel.org, iommu@lists.linux-foundation.org, joro@8bytes.org, robh+dt@kernel.org, mark.rutland@arm.com, lorenzo.pieralisi@arm.com, guohanjun@huawei.com, sudeep.holla@arm.com, rjw@rjwysocki.net, lenb@kernel.org, will@kernel.org, robin.murphy@arm.com, bhelgaas@google.com, jonathan.cameron@huawei.com, zhangfei.gao@linaro.org Subject: Re: [PATCH v3 13/13] iommu/arm-smmu-v3: Add support for PCI PASID Message-ID: <20191218161323.GI2371701@myrica> References: <20191209180514.272727-1-jean-philippe@linaro.org> <20191209180514.272727-14-jean-philippe@linaro.org> <551ce08c-4160-72c9-05b5-97799f6e5d25@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <551ce08c-4160-72c9-05b5-97799f6e5d25@redhat.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Dec 18, 2019 at 11:17:55AM +0100, Auger Eric wrote: > > +static int arm_smmu_enable_pasid(struct arm_smmu_master *master) > > +{ > > + int ret; > > + int features; > > + int num_pasids; > > + struct pci_dev *pdev; > > + > > + if (!dev_is_pci(master->dev)) > > + return -ENODEV; > > + > > + pdev = to_pci_dev(master->dev); > > + > > + features = pci_pasid_features(pdev); > > + if (features < 0) > > + return -ENODEV; > why -ENODEV? Right that should return features. The below should return num_pasids. > > + > > + num_pasids = pci_max_pasids(pdev); > > + if (num_pasids <= 0) > > + return -ENODEV; > > + > > + ret = pci_enable_pasid(pdev, features); > > + if (!ret) > > + master->ssid_bits = min_t(u8, ilog2(num_pasids), > > + master->smmu->ssid_bits); > so here we are ;-) > > + return ret; > > +} > > + > > +static void arm_smmu_disable_pasid(struct arm_smmu_master *master) > > +{ > > + struct pci_dev *pdev; > > + > > + if (!dev_is_pci(master->dev)) > > + return; > > + > > + pdev = to_pci_dev(master->dev); > > + > > + if (!pdev->pasid_enabled) > > + return; > > + > > + master->ssid_bits = 0; > > + pci_disable_pasid(pdev); > > +} > > + > > static void arm_smmu_detach_dev(struct arm_smmu_master *master) > > { > > unsigned long flags; > > @@ -2851,13 +2894,16 @@ static int arm_smmu_add_device(struct device *dev) > > > > master->ssid_bits = min(smmu->ssid_bits, fwspec->num_pasid_bits); > > > > + /* Note that PASID must be enabled before, and disabled after ATS */ > > + arm_smmu_enable_pasid(master); > No error handling? The device still works if PASID isn't supported or cannot be enabled, it just won't have some capabilities (IOMMU_DEV_FEAT_AUX and IOMMU_DEV_FEAT_SVA), so I don't think add_device should return an error. But it's a good point, I think at least printing an error like arm_smmu_enable_ats() does would be better. Thanks, Jean