1 files changed, 49 insertions, 30 deletions

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index f17a1113f3d6..33e2a9b5d339 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -485,11 +485,12 @@ static void iommu_deinit_device(struct device *dev)
 	dev_iommu_free(dev);
 }
 
+DEFINE_MUTEX(iommu_probe_device_lock);
+
 static int __iommu_probe_device(struct device *dev, struct list_head *group_list)
 {
 	const struct iommu_ops *ops = dev->bus->iommu_ops;
 	struct iommu_group *group;
-	static DEFINE_MUTEX(iommu_probe_device_lock);
 	struct group_device *gdev;
 	int ret;
 
@@ -502,17 +503,15 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list
 	 * probably be able to use device_lock() here to minimise the scope,
 	 * but for now enforcing a simple global ordering is fine.
 	 */
-	mutex_lock(&iommu_probe_device_lock);
+	lockdep_assert_held(&iommu_probe_device_lock);
 
 	/* Device is probed already if in a group */
-	if (dev->iommu_group) {
-		ret = 0;
-		goto out_unlock;
-	}
+	if (dev->iommu_group)
+		return 0;
 
 	ret = iommu_init_device(dev, ops);
 	if (ret)
-		goto out_unlock;
+		return ret;
 
 	group = dev->iommu_group;
 	gdev = iommu_group_alloc_device(group, dev);
@@ -548,7 +547,6 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list
 			list_add_tail(&group->entry, group_list);
 	}
 	mutex_unlock(&group->mutex);
-	mutex_unlock(&iommu_probe_device_lock);
 
 	if (dev_is_pci(dev))
 		iommu_dma_set_pci_32bit_workaround(dev);
@@ -562,8 +560,6 @@ err_put_group:
 	iommu_deinit_device(dev);
 	mutex_unlock(&group->mutex);
 	iommu_group_put(group);
-out_unlock:
-	mutex_unlock(&iommu_probe_device_lock);
 
 	return ret;
 }
@@ -573,7 +569,9 @@ int iommu_probe_device(struct device *dev)
 	const struct iommu_ops *ops;
 	int ret;
 
+	mutex_lock(&iommu_probe_device_lock);
 	ret = __iommu_probe_device(dev, NULL);
+	mutex_unlock(&iommu_probe_device_lock);
 	if (ret)
 		return ret;
 
@@ -1788,7 +1786,7 @@ iommu_group_alloc_default_domain(struct iommu_group *group, int req_type)
 	 */
 	if (ops->default_domain) {
 		if (req_type)
-			return NULL;
+			return ERR_PTR(-EINVAL);
 		return ops->default_domain;
 	}
 
@@ -1797,15 +1795,15 @@ iommu_group_alloc_default_domain(struct iommu_group *group, int req_type)
 
 	/* The driver gave no guidance on what type to use, try the default */
 	dom = __iommu_group_alloc_default_domain(group, iommu_def_domain_type);
-	if (dom)
+	if (!IS_ERR(dom))
 		return dom;
 
 	/* Otherwise IDENTITY and DMA_FQ defaults will try DMA */
 	if (iommu_def_domain_type == IOMMU_DOMAIN_DMA)
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	dom = __iommu_group_alloc_default_domain(group, IOMMU_DOMAIN_DMA);
-	if (!dom)
-		return NULL;
+	if (IS_ERR(dom))
+		return dom;
 
 	pr_warn("Failed to allocate default IOMMU domain of type %u for group %s - Falling back to IOMMU_DOMAIN_DMA",
 		iommu_def_domain_type, group->name);
@@ -1822,7 +1820,9 @@ static int probe_iommu_group(struct device *dev, void *data)
 	struct list_head *group_list = data;
 	int ret;
 
+	mutex_lock(&iommu_probe_device_lock);
 	ret = __iommu_probe_device(dev, group_list);
+	mutex_unlock(&iommu_probe_device_lock);
 	if (ret == -ENODEV)
 		ret = 0;
 
@@ -2094,10 +2094,17 @@ static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops,
 	else if (ops->domain_alloc)
 		domain = ops->domain_alloc(alloc_type);
 	else
-		return NULL;
+		return ERR_PTR(-EOPNOTSUPP);
 
+	/*
+	 * Many domain_alloc ops now return ERR_PTR, make things easier for the
+	 * driver by accepting ERR_PTR from all domain_alloc ops instead of
+	 * having two rules.
+	 */
+	if (IS_ERR(domain))
+		return domain;
 	if (!domain)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	domain->type = type;
 	/*
@@ -2110,9 +2117,14 @@ static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops,
 	if (!domain->ops)
 		domain->ops = ops->default_domain_ops;
 
-	if (iommu_is_dma_domain(domain) && iommu_get_dma_cookie(domain)) {
-		iommu_domain_free(domain);
-		domain = NULL;
+	if (iommu_is_dma_domain(domain)) {
+		int rc;
+
+		rc = iommu_get_dma_cookie(domain);
+		if (rc) {
+			iommu_domain_free(domain);
+			return ERR_PTR(rc);
+		}
 	}
 	return domain;
 }
@@ -2129,10 +2141,15 @@ __iommu_group_domain_alloc(struct iommu_group *group, unsigned int type)
 
 struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus)
 {
+	struct iommu_domain *domain;
+
 	if (bus == NULL || bus->iommu_ops == NULL)
 		return NULL;
-	return __iommu_domain_alloc(bus->iommu_ops, NULL,
+	domain = __iommu_domain_alloc(bus->iommu_ops, NULL,
 				    IOMMU_DOMAIN_UNMANAGED);
+	if (IS_ERR(domain))
+		return NULL;
+	return domain;
 }
 EXPORT_SYMBOL_GPL(iommu_domain_alloc);
 
@@ -3041,8 +3058,8 @@ static int iommu_setup_default_domain(struct iommu_group *group,
 		return -EINVAL;
 
 	dom = iommu_group_alloc_default_domain(group, req_type);
-	if (!dom)
-		return -ENODEV;
+	if (IS_ERR(dom))
+		return PTR_ERR(dom);
 
 	if (group->default_domain == dom)
 		return 0;
@@ -3243,21 +3260,23 @@ void iommu_device_unuse_default_domain(struct device *dev)
 
 static int __iommu_group_alloc_blocking_domain(struct iommu_group *group)
 {
+	struct iommu_domain *domain;
+
 	if (group->blocking_domain)
 		return 0;
 
-	group->blocking_domain =
-		__iommu_group_domain_alloc(group, IOMMU_DOMAIN_BLOCKED);
-	if (!group->blocking_domain) {
+	domain = __iommu_group_domain_alloc(group, IOMMU_DOMAIN_BLOCKED);
+	if (IS_ERR(domain)) {
 		/*
 		 * For drivers that do not yet understand IOMMU_DOMAIN_BLOCKED
 		 * create an empty domain instead.
 		 */
-		group->blocking_domain = __iommu_group_domain_alloc(
-			group, IOMMU_DOMAIN_UNMANAGED);
-		if (!group->blocking_domain)
-			return -EINVAL;
+		domain = __iommu_group_domain_alloc(group,
+						    IOMMU_DOMAIN_UNMANAGED);
+		if (IS_ERR(domain))
+			return PTR_ERR(domain);
 	}
+	group->blocking_domain = domain;
 	return 0;
 }