[RFC PATCH 07/34] iommu: Add probe_device() and remove_device() call-backs

From: Joerg Roedel <joro@8bytes.org>
To: Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Kukjin Kim <kgene@kernel.org>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	David Woodhouse <dwmw2@infradead.org>,
	Lu Baolu <baolu.lu@linux.intel.com>,
	Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Rob Clark <robdclark@gmail.com>, Heiko Stuebner <heiko@sntech.de>,
	Gerald Schaefer <gerald.schaefer@de.ibm.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	linux-samsung-soc@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-mediatek@lists.infradead.org,
	linux-rockchip@lists.infradead.org, linux-s390@vger.kernel.org,
	linux-tegra@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	Joerg Roedel <jroedel@suse.de>
Subject: [RFC PATCH 07/34] iommu: Add probe_device() and remove_device() call-backs
Date: Tue,  7 Apr 2020 20:37:15 +0200	[thread overview]
Message-ID: <20200407183742.4344-8-joro@8bytes.org> (raw)
In-Reply-To: <20200407183742.4344-1-joro@8bytes.org>

From: Joerg Roedel <jroedel@suse.de>

Add call-backs to 'struct iommu_ops' as an alternative to the
add_device() and remove_device() call-backs, which will be removed when
all drivers are converted.

The new call-backs will not setupt IOMMU groups and domains anymore,
so also add a probe_finalize() call-back where the IOMMU driver can do
per-device setup work which require the device to be set up with a
group and a domain.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/iommu.c | 63 ++++++++++++++++++++++++++++++++++++++-----
 include/linux/iommu.h |  9 +++++++
 2 files changed, 66 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5877abd9b693..6cfe7799dc8c 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -174,6 +174,36 @@ static void dev_iommu_free(struct device *dev)
 	dev->iommu = NULL;
 }
 
+static int __iommu_probe_device(struct device *dev)
+{
+	const struct iommu_ops *ops = dev->bus->iommu_ops;
+	struct iommu_device *iommu_dev;
+	struct iommu_group *group;
+	int ret;
+
+	iommu_dev = ops->probe_device(dev);
+	if (IS_ERR(iommu_dev))
+		return PTR_ERR(iommu_dev);
+
+	dev->iommu->iommu_dev = iommu_dev;
+
+	group = iommu_group_get_for_dev(dev);
+	if (!IS_ERR(group)) {
+		ret = PTR_ERR(group);
+		goto out_release;
+	}
+	iommu_group_put(group);
+
+	iommu_device_link(iommu_dev, dev);
+
+	return 0;
+
+out_release:
+	ops->release_device(dev);
+
+	return ret;
+}
+
 int iommu_probe_device(struct device *dev)
 {
 	const struct iommu_ops *ops = dev->bus->iommu_ops;
@@ -191,10 +221,17 @@ int iommu_probe_device(struct device *dev)
 		goto err_free_dev_param;
 	}
 
-	ret = ops->add_device(dev);
+	if (ops->probe_device)
+		ret = __iommu_probe_device(dev);
+	else
+		ret = ops->add_device(dev);
+
 	if (ret)
 		goto err_module_put;
 
+	if (ops->probe_finalize)
+		ops->probe_finalize(dev);
+
 	return 0;
 
 err_module_put:
@@ -204,17 +241,31 @@ int iommu_probe_device(struct device *dev)
 	return ret;
 }
 
+static void __iommu_release_device(struct device *dev)
+{
+	const struct iommu_ops *ops = dev->bus->iommu_ops;
+
+	iommu_device_unlink(dev->iommu->iommu_dev, dev);
+
+	iommu_group_remove_device(dev);
+
+	ops->release_device(dev);
+}
+
 void iommu_release_device(struct device *dev)
 {
 	const struct iommu_ops *ops = dev->bus->iommu_ops;
 
-	if (dev->iommu_group)
+	if (!dev->iommu)
+		return;
+
+	if (ops->release_device)
+		__iommu_release_device(dev);
+	else if (dev->iommu_group)
 		ops->remove_device(dev);
 
-	if (dev->iommu) {
-		module_put(ops->owner);
-		dev_iommu_free(dev);
-	}
+	module_put(ops->owner);
+	dev_iommu_free(dev);
 }
 
 static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 1f027b07e499..30170d191e5e 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -225,6 +225,10 @@ struct iommu_iotlb_gather {
  * @iova_to_phys: translate iova to physical address
  * @add_device: add device to iommu grouping
  * @remove_device: remove device from iommu grouping
+ * @probe_device: Add device to iommu driver handling
+ * @release_device: Remove device from iommu driver handling
+ * @probe_finalize: Do final setup work after the device is added to an IOMMU
+ *                  group and attached to the groups domain
  * @device_group: find iommu group for a particular device
  * @domain_get_attr: Query domain attributes
  * @domain_set_attr: Change domain attributes
@@ -275,6 +279,9 @@ struct iommu_ops {
 	phys_addr_t (*iova_to_phys)(struct iommu_domain *domain, dma_addr_t iova);
 	int (*add_device)(struct device *dev);
 	void (*remove_device)(struct device *dev);
+	struct iommu_device *(*probe_device)(struct device *dev);
+	void (*release_device)(struct device *dev);
+	void (*probe_finalize)(struct device *dev);
 	struct iommu_group *(*device_group)(struct device *dev);
 	int (*domain_get_attr)(struct iommu_domain *domain,
 			       enum iommu_attr attr, void *data);
@@ -375,6 +382,7 @@ struct iommu_fault_param {
  *
  * @fault_param: IOMMU detected device fault reporting data
  * @fwspec:	 IOMMU fwspec data
+ * @iommu_dev:	 IOMMU device this device is linked to
  * @priv:	 IOMMU Driver private data
  *
  * TODO: migrate other per device data pointers under iommu_dev_data, e.g.
@@ -384,6 +392,7 @@ struct dev_iommu {
 	struct mutex lock;
 	struct iommu_fault_param	*fault_param;
 	struct iommu_fwspec		*fwspec;
+	struct iommu_device		*iommu_dev;
 	void				*priv;
 };
 
-- 
2.17.1

