[RFC PATCH 33/34] iommu: Remove add_device()/remove_device() code-paths

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 33/34] iommu: Remove add_device()/remove_device() code-paths
Date: Tue,  7 Apr 2020 20:37:41 +0200	[thread overview]
Message-ID: <20200407183742.4344-34-joro@8bytes.org> (raw)
In-Reply-To: <20200407183742.4344-1-joro@8bytes.org>

From: Joerg Roedel <jroedel@suse.de>

All drivers are converted to use the probe/release_device()
call-backs, so the add_device/remove_device() pointers are unused and
the code using them can be removed.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/iommu.c | 145 ++++++++----------------------------------
 include/linux/iommu.h |   4 --
 2 files changed, 27 insertions(+), 122 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index cf25c1e48830..d9032f9d597c 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -220,7 +220,7 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list
 	return ret;
 }
 
-static int __iommu_probe_device_helper(struct device *dev)
+int iommu_probe_device(struct device *dev)
 {
 	const struct iommu_ops *ops = dev->bus->iommu_ops;
 	struct iommu_group *group;
@@ -264,70 +264,17 @@ static int __iommu_probe_device_helper(struct device *dev)
 
 }
 
-int iommu_probe_device(struct device *dev)
+void iommu_release_device(struct device *dev)
 {
 	const struct iommu_ops *ops = dev->bus->iommu_ops;
-	struct iommu_group *group;
-	int ret;
-
-	WARN_ON(dev->iommu_group);
-
-	if (!ops)
-		return -EINVAL;
-
-	if (!dev_iommu_get(dev))
-		return -ENOMEM;
-
-	if (!try_module_get(ops->owner)) {
-		ret = -EINVAL;
-		goto err_free_dev_param;
-	}
-
-	if (ops->probe_device)
-		return __iommu_probe_device_helper(dev);
-
-	ret = ops->add_device(dev);
-	if (ret)
-		goto err_module_put;
 
-	group = iommu_group_get(dev);
-	iommu_create_device_direct_mappings(group, dev);
-	iommu_group_put(group);
-
-	if (ops->probe_finalize)
-		ops->probe_finalize(dev);
-
-	return 0;
-
-err_module_put:
-	module_put(ops->owner);
-err_free_dev_param:
-	dev_iommu_free(dev);
-	return ret;
-}
-
-static void __iommu_release_device(struct device *dev)
-{
-	const struct iommu_ops *ops = dev->bus->iommu_ops;
+	if (!dev->iommu)
+		return;
 
 	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)
-		return;
-
-	if (ops->release_device)
-		__iommu_release_device(dev);
-	else if (dev->iommu_group)
-		ops->remove_device(dev);
 
 	module_put(ops->owner);
 	dev_iommu_free(dev);
@@ -1560,23 +1507,6 @@ struct iommu_group *iommu_group_get_for_dev(struct device *dev)
 	if (ret)
 		goto out_put_group;
 
-	/*
-	 * Try to allocate a default domain - needs support from the
-	 * IOMMU driver. There are still some drivers which don't support
-	 * default domains, so the return value is not yet checked. Only
-	 * allocate the domain here when the driver still has the
-	 * add_device/remove_device call-backs implemented.
-	 */
-	if (!ops->probe_device) {
-		iommu_alloc_default_domain(dev);
-
-		if (group->default_domain)
-			ret = __iommu_attach_device(group->default_domain, dev);
-
-		if (ret)
-			goto out_put_group;
-	}
-
 	return group;
 
 out_put_group:
@@ -1591,21 +1521,6 @@ struct iommu_domain *iommu_group_default_domain(struct iommu_group *group)
 	return group->default_domain;
 }
 
-static int add_iommu_group(struct device *dev, void *data)
-{
-	int ret = iommu_probe_device(dev);
-
-	/*
-	 * We ignore -ENODEV errors for now, as they just mean that the
-	 * device is not translated by an IOMMU. We still care about
-	 * other errors and fail to initialize when they happen.
-	 */
-	if (ret == -ENODEV)
-		ret = 0;
-
-	return ret;
-}
-
 static int probe_iommu_group(struct device *dev, void *data)
 {
 	const struct iommu_ops *ops = dev->bus->iommu_ops;
@@ -1789,45 +1704,39 @@ static int iommu_group_create_direct_mappings(struct iommu_group *group)
 
 int bus_iommu_probe(struct bus_type *bus)
 {
-	const struct iommu_ops *ops = bus->iommu_ops;
+	struct iommu_group *group, *next;
+	LIST_HEAD(group_list);
 	int ret;
 
-	if (ops->probe_device) {
-		struct iommu_group *group, *next;
-		LIST_HEAD(group_list);
-
-		/*
-		 * This code-path does not allocate the default domain when
-		 * creating the iommu group, so do it after the groups are
-		 * created.
-		 */
-		ret = bus_for_each_dev(bus, NULL, &group_list, probe_iommu_group);
-		if (ret)
-			return ret;
+	/*
+	 * This code-path does not allocate the default domain when
+	 * creating the iommu group, so do it after the groups are
+	 * created.
+	 */
+	ret = bus_for_each_dev(bus, NULL, &group_list, probe_iommu_group);
+	if (ret)
+		return ret;
 
-		list_for_each_entry_safe(group, next, &group_list, entry) {
-			/* Remove item from the list */
-			list_del_init(&group->entry);
+	list_for_each_entry_safe(group, next, &group_list, entry) {
+		/* Remove item from the list */
+		list_del_init(&group->entry);
 
-			mutex_lock(&group->mutex);
+		mutex_lock(&group->mutex);
 
-			/* Try to allocate default domain */
-			probe_alloc_default_domain(bus, group);
+		/* Try to allocate default domain */
+		probe_alloc_default_domain(bus, group);
 
-			if (!group->default_domain)
-				continue;
+		if (!group->default_domain)
+			continue;
 
-			iommu_group_create_direct_mappings(group);
+		iommu_group_create_direct_mappings(group);
 
-			ret = __iommu_group_dma_attach(group);
+		ret = __iommu_group_dma_attach(group);
 
-			mutex_unlock(&group->mutex);
+		mutex_unlock(&group->mutex);
 
-			if (ret)
-				break;
-		}
-	} else {
-		ret = bus_for_each_dev(bus, NULL, NULL, add_iommu_group);
+		if (ret)
+			break;
 	}
 
 	return ret;
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index fea1622408ad..dd076366383f 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -223,8 +223,6 @@ struct iommu_iotlb_gather {
  * @iotlb_sync: Flush all queued ranges from the hardware TLBs and empty flush
  *            queue
  * @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
@@ -277,8 +275,6 @@ struct iommu_ops {
 	void (*iotlb_sync)(struct iommu_domain *domain,
 			   struct iommu_iotlb_gather *iotlb_gather);
 	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);
-- 
2.17.1

