From: joro@8bytes•org (Joerg Roedel)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v5 5/6] iommu/mediatek: Add mt8173 IOMMU driver
Date: Wed, 14 Oct 2015 14:53:09 +0200 [thread overview]
Message-ID: <20151014125309.GO27420@8bytes.org> (raw)
In-Reply-To: <1444357388-30257-6-git-send-email-yong.wu@mediatek.com>
On Fri, Oct 09, 2015 at 10:23:07AM +0800, Yong Wu wrote:
> + /*
> + * There is a domain for each a iommu device in normal case.
> + * But MTK only has one iommu domain called the m4u domain which all
> + * the multimedia HW share. Here we reserve one as the m4u domain and
> + * free the others.
> + *
> + * And the attach_device that from __iommu_setup_dma_ops
> + * will be called earlier than probe.
> + */
Okay, with this being the case, you need to put all devices behind one
IOMMU into the same iommu-group, because the IOMMU can't really isolate
the devices from each other.
> +static int mtk_iommu_add_device(struct device *dev)
> +{
> + struct iommu_group *group;
> + struct mtk_iommu_client_priv *priv;
> + struct mtk_iommu_domain *m4udom;
> + struct iommu_domain *domain;
> + int ret;
> +
> + if (!dev->archdata.iommu) /* Not a iommu client device */
> + return -ENODEV;
> +
> + group = iommu_group_get(dev);
> + if (!group) {
> + group = iommu_group_alloc();
> + if (IS_ERR(group)) {
> + dev_err(dev, "Failed to allocate IOMMU group\n");
> + return PTR_ERR(group);
> + }
> + }
> +
> + ret = iommu_group_add_device(group, dev);
> + if (ret) {
> + dev_err(dev, "Failed to add IOMMU group\n");
> + goto err_group_put;
> + }
> +
> + domain = iommu_get_domain_for_dev(dev);
> + if (!domain) {
> + /*
> + * Get the m4u iommu domain from the m4u device.
> + * Attach all the client devices into the m4u domain.
> + */
> + priv = dev->archdata.iommu;
> + m4udom = dev_get_drvdata(priv->m4udev);
> + ret = iommu_attach_group(&m4udom->domain, group);
> + if (ret)
> + dev_err(dev, "Failed to attach IOMMU group\n");
> + }
> +
> +err_group_put:
> + iommu_group_put(group);
> + return ret;
> +}
Here it looks like you are allocating one group for each device. As I
said, all devices need to be in one group.
Joerg
next prev parent reply other threads:[~2015-10-14 12:53 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-09 2:23 [PATCH v5 0/6] MT8173 IOMMU SUPPORT Yong Wu
2015-10-09 2:23 ` [PATCH v5 1/6] dt-bindings: iommu: Add binding for mediatek IOMMU Yong Wu
2015-10-09 2:23 ` [PATCH v5 2/6] dt-bindings: mediatek: Add smi dts binding Yong Wu
2015-10-09 2:23 ` [PATCH v5 3/6] iommu: add ARM short descriptor page table allocator Yong Wu
2015-10-14 12:54 ` Joerg Roedel
2015-10-15 17:20 ` Will Deacon
2015-11-06 8:42 ` Yong Wu
2015-11-06 11:42 ` Will Deacon
2015-10-09 2:23 ` [PATCH v5 4/6] memory: mediatek: Add SMI driver Yong Wu
2015-10-27 13:24 ` Robin Murphy
2015-10-31 8:32 ` Yong Wu
2015-10-09 2:23 ` [PATCH v5 5/6] iommu/mediatek: Add mt8173 IOMMU driver Yong Wu
2015-10-14 12:53 ` Joerg Roedel [this message]
2015-10-26 5:23 ` Yong Wu
2015-10-27 13:25 ` Robin Murphy
2015-10-31 8:28 ` Yong Wu
2015-10-09 2:23 ` [PATCH v5 6/6] dts: mt8173: Add iommu/smi nodes for mt8173 Yong Wu
2015-10-14 12:56 ` [PATCH v5 0/6] MT8173 IOMMU SUPPORT Joerg Roedel
2015-10-22 4:40 ` Yong Wu
2015-10-23 9:26 ` Joerg Roedel
2015-11-24 5:58 ` Yong Wu
2015-11-24 10:38 ` Thierry Reding
2015-11-25 1:30 ` Yong Wu
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