1 files changed, 85 insertions, 86 deletions

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5f6a85aea501..b3f847b25b4f 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -371,6 +371,30 @@ err_unlock:
 	return ret;
 }
 
+static bool iommu_is_attach_deferred(struct device *dev)
+{
+	const struct iommu_ops *ops = dev_iommu_ops(dev);
+
+	if (ops->is_attach_deferred)
+		return ops->is_attach_deferred(dev);
+
+	return false;
+}
+
+static int iommu_group_do_dma_first_attach(struct device *dev, void *data)
+{
+	struct iommu_domain *domain = data;
+
+	lockdep_assert_held(&dev->iommu_group->mutex);
+
+	if (iommu_is_attach_deferred(dev)) {
+		dev->iommu->attach_deferred = 1;
+		return 0;
+	}
+
+	return __iommu_attach_device(domain, dev);
+}
+
 int iommu_probe_device(struct device *dev)
 {
 	const struct iommu_ops *ops;
@@ -401,7 +425,7 @@ int iommu_probe_device(struct device *dev)
 	 * attach the default domain.
 	 */
 	if (group->default_domain && !group->owner) {
-		ret = __iommu_attach_device(group->default_domain, dev);
+		ret = iommu_group_do_dma_first_attach(dev, group->default_domain);
 		if (ret) {
 			mutex_unlock(&group->mutex);
 			iommu_group_put(group);
@@ -774,12 +798,16 @@ struct iommu_group *iommu_group_alloc(void)
 
 	ret = iommu_group_create_file(group,
 				      &iommu_group_attr_reserved_regions);
-	if (ret)
+	if (ret) {
+		kobject_put(group->devices_kobj);
 		return ERR_PTR(ret);
+	}
 
 	ret = iommu_group_create_file(group, &iommu_group_attr_type);
-	if (ret)
+	if (ret) {
+		kobject_put(group->devices_kobj);
 		return ERR_PTR(ret);
+	}
 
 	pr_debug("Allocated group %d\n", group->id);
 
@@ -930,7 +958,7 @@ map_end:
 			if (map_size) {
 				ret = iommu_map(domain, addr - map_size,
 						addr - map_size, map_size,
-						entry->prot);
+						entry->prot, GFP_KERNEL);
 				if (ret)
 					goto out;
 				map_size = 0;
@@ -947,16 +975,6 @@ out:
 	return ret;
 }
 
-static bool iommu_is_attach_deferred(struct device *dev)
-{
-	const struct iommu_ops *ops = dev_iommu_ops(dev);
-
-	if (ops->is_attach_deferred)
-		return ops->is_attach_deferred(dev);
-
-	return false;
-}
-
 /**
  * iommu_group_add_device - add a device to an iommu group
  * @group: the group into which to add the device (reference should be held)
@@ -1009,8 +1027,8 @@ rename:
 
 	mutex_lock(&group->mutex);
 	list_add_tail(&device->list, &group->devices);
-	if (group->domain  && !iommu_is_attach_deferred(dev))
-		ret = __iommu_attach_device(group->domain, dev);
+	if (group->domain)
+		ret = iommu_group_do_dma_first_attach(dev, group->domain);
 	mutex_unlock(&group->mutex);
 	if (ret)
 		goto err_put_group;
@@ -1776,21 +1794,10 @@ static void probe_alloc_default_domain(struct bus_type *bus,
 
 }
 
-static int iommu_group_do_dma_attach(struct device *dev, void *data)
-{
-	struct iommu_domain *domain = data;
-	int ret = 0;
-
-	if (!iommu_is_attach_deferred(dev))
-		ret = __iommu_attach_device(domain, dev);
-
-	return ret;
-}
-
-static int __iommu_group_dma_attach(struct iommu_group *group)
+static int __iommu_group_dma_first_attach(struct iommu_group *group)
 {
 	return __iommu_group_for_each_dev(group, group->default_domain,
-					  iommu_group_do_dma_attach);
+					  iommu_group_do_dma_first_attach);
 }
 
 static int iommu_group_do_probe_finalize(struct device *dev, void *data)
@@ -1855,7 +1862,7 @@ int bus_iommu_probe(struct bus_type *bus)
 
 		iommu_group_create_direct_mappings(group);
 
-		ret = __iommu_group_dma_attach(group);
+		ret = __iommu_group_dma_first_attach(group);
 
 		mutex_unlock(&group->mutex);
 
@@ -1987,9 +1994,11 @@ static int __iommu_attach_device(struct iommu_domain *domain,
 		return -ENODEV;
 
 	ret = domain->ops->attach_dev(domain, dev);
-	if (!ret)
-		trace_attach_device_to_domain(dev);
-	return ret;
+	if (ret)
+		return ret;
+	dev->iommu->attach_deferred = 0;
+	trace_attach_device_to_domain(dev);
+	return 0;
 }
 
 /**
@@ -2034,22 +2043,12 @@ EXPORT_SYMBOL_GPL(iommu_attach_device);
 
 int iommu_deferred_attach(struct device *dev, struct iommu_domain *domain)
 {
-	if (iommu_is_attach_deferred(dev))
+	if (dev->iommu && dev->iommu->attach_deferred)
 		return __iommu_attach_device(domain, dev);
 
 	return 0;
 }
 
-static void __iommu_detach_device(struct iommu_domain *domain,
-				  struct device *dev)
-{
-	if (iommu_is_attach_deferred(dev))
-		return;
-
-	domain->ops->detach_dev(domain, dev);
-	trace_detach_device_from_domain(dev);
-}
-
 void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
 {
 	struct iommu_group *group;
@@ -2124,8 +2123,22 @@ static int __iommu_attach_group(struct iommu_domain *domain,
 
 	ret = __iommu_group_for_each_dev(group, domain,
 					 iommu_group_do_attach_device);
-	if (ret == 0)
+	if (ret == 0) {
 		group->domain = domain;
+	} else {
+		/*
+		 * To recover from the case when certain device within the
+		 * group fails to attach to the new domain, we need force
+		 * attaching all devices back to the old domain. The old
+		 * domain is compatible for all devices in the group,
+		 * hence the iommu driver should always return success.
+		 */
+		struct iommu_domain *old_domain = group->domain;
+
+		group->domain = NULL;
+		WARN(__iommu_group_set_domain(group, old_domain),
+		     "iommu driver failed to attach a compatible domain");
+	}
 
 	return ret;
 }
@@ -2154,11 +2167,12 @@ int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group)
 }
 EXPORT_SYMBOL_GPL(iommu_attach_group);
 
-static int iommu_group_do_detach_device(struct device *dev, void *data)
+static int iommu_group_do_set_platform_dma(struct device *dev, void *data)
 {
-	struct iommu_domain *domain = data;
+	const struct iommu_ops *ops = dev_iommu_ops(dev);
 
-	__iommu_detach_device(domain, dev);
+	if (!WARN_ON(!ops->set_platform_dma_ops))
+		ops->set_platform_dma_ops(dev);
 
 	return 0;
 }
@@ -2172,15 +2186,13 @@ static int __iommu_group_set_domain(struct iommu_group *group,
 		return 0;
 
 	/*
-	 * New drivers should support default domains and so the detach_dev() op
-	 * will never be called. Otherwise the NULL domain represents some
+	 * New drivers should support default domains, so set_platform_dma()
+	 * op will never be called. Otherwise the NULL domain represents some
 	 * platform specific behavior.
 	 */
 	if (!new_domain) {
-		if (WARN_ON(!group->domain->ops->detach_dev))
-			return -EINVAL;
-		__iommu_group_for_each_dev(group, group->domain,
-					   iommu_group_do_detach_device);
+		__iommu_group_for_each_dev(group, NULL,
+					   iommu_group_do_set_platform_dma);
 		group->domain = NULL;
 		return 0;
 	}
@@ -2360,34 +2372,27 @@ static int __iommu_map(struct iommu_domain *domain, unsigned long iova,
 	return ret;
 }
 
-static int _iommu_map(struct iommu_domain *domain, unsigned long iova,
-		      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
+int iommu_map(struct iommu_domain *domain, unsigned long iova,
+	      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
 {
 	const struct iommu_domain_ops *ops = domain->ops;
 	int ret;
 
+	might_sleep_if(gfpflags_allow_blocking(gfp));
+
+	/* Discourage passing strange GFP flags */
+	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |
+				__GFP_HIGHMEM)))
+		return -EINVAL;
+
 	ret = __iommu_map(domain, iova, paddr, size, prot, gfp);
 	if (ret == 0 && ops->iotlb_sync_map)
 		ops->iotlb_sync_map(domain, iova, size);
 
 	return ret;
 }
-
-int iommu_map(struct iommu_domain *domain, unsigned long iova,
-	      phys_addr_t paddr, size_t size, int prot)
-{
-	might_sleep();
-	return _iommu_map(domain, iova, paddr, size, prot, GFP_KERNEL);
-}
 EXPORT_SYMBOL_GPL(iommu_map);
 
-int iommu_map_atomic(struct iommu_domain *domain, unsigned long iova,
-	      phys_addr_t paddr, size_t size, int prot)
-{
-	return _iommu_map(domain, iova, paddr, size, prot, GFP_ATOMIC);
-}
-EXPORT_SYMBOL_GPL(iommu_map_atomic);
-
 static size_t __iommu_unmap_pages(struct iommu_domain *domain,
 				  unsigned long iova, size_t size,
 				  struct iommu_iotlb_gather *iotlb_gather)
@@ -2477,9 +2482,9 @@ size_t iommu_unmap_fast(struct iommu_domain *domain,
 }
 EXPORT_SYMBOL_GPL(iommu_unmap_fast);
 
-static ssize_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
-		struct scatterlist *sg, unsigned int nents, int prot,
-		gfp_t gfp)
+ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
+		     struct scatterlist *sg, unsigned int nents, int prot,
+		     gfp_t gfp)
 {
 	const struct iommu_domain_ops *ops = domain->ops;
 	size_t len = 0, mapped = 0;
@@ -2487,6 +2492,13 @@ static ssize_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
 	unsigned int i = 0;
 	int ret;
 
+	might_sleep_if(gfpflags_allow_blocking(gfp));
+
+	/* Discourage passing strange GFP flags */
+	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |
+				__GFP_HIGHMEM)))
+		return -EINVAL;
+
 	while (i <= nents) {
 		phys_addr_t s_phys = sg_phys(sg);
 
@@ -2526,21 +2538,8 @@ out_err:
 
 	return ret;
 }
-
-ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
-		     struct scatterlist *sg, unsigned int nents, int prot)
-{
-	might_sleep();
-	return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_KERNEL);
-}
 EXPORT_SYMBOL_GPL(iommu_map_sg);
 
-ssize_t iommu_map_sg_atomic(struct iommu_domain *domain, unsigned long iova,
-		    struct scatterlist *sg, unsigned int nents, int prot)
-{
-	return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_ATOMIC);
-}
-
 /**
  * report_iommu_fault() - report about an IOMMU fault to the IOMMU framework
  * @domain: the iommu domain where the fault has happened