[PATCH v2 2/3] iommu: Retire detach_dev domain ops

[Lu Baolu <baolu.lu@linux.intel.com>]

As no IOMMU driver provides detach_dev domain ops callback now, retire
this callback and make the detach_dev calls in iommu core through the
blocking domain.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h |  2 --
 drivers/iommu/iommu.c | 31 ++++---------------------------
 2 files changed, 4 insertions(+), 29 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 266ef281cbd5..1e9fecfb23a7 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -274,7 +274,6 @@ struct iommu_ops {
 /**
  * struct iommu_domain_ops - domain specific operations
  * @attach_dev: attach an iommu domain to a device
- * @detach_dev: detach an iommu domain from a device
  * @set_dev_pasid: set an iommu domain to a pasid of device
  * @map: map a physically contiguous memory region to an iommu domain
  * @map_pages: map a physically contiguous set of pages of the same size to
@@ -295,7 +294,6 @@ struct iommu_ops {
  */
 struct iommu_domain_ops {
 	int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
-	void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
 	int (*set_dev_pasid)(struct iommu_domain *domain, struct device *dev,
 			     ioasid_t pasid);
 
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 9e84f58440dd..ad34e4df1aad 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2047,16 +2047,6 @@ int iommu_deferred_attach(struct device *dev, struct iommu_domain *domain)
 	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;
@@ -2149,15 +2139,6 @@ 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)
-{
-	struct iommu_domain *domain = data;
-
-	__iommu_detach_device(domain, dev);
-
-	return 0;
-}
-
 static int __iommu_group_set_domain(struct iommu_group *group,
 				    struct iommu_domain *new_domain)
 {
@@ -2167,17 +2148,13 @@ 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
-	 * platform specific behavior.
+	 * The NULL domain represents some platform specific behavior.
+	 * Attaching the blocking domain instead.
 	 */
 	if (!new_domain) {
-		if (WARN_ON(!group->domain->ops->detach_dev))
+		if (WARN_ON(!group->blocking_domain))
 			return -EINVAL;
-		__iommu_group_for_each_dev(group, group->domain,
-					   iommu_group_do_detach_device);
-		group->domain = NULL;
-		return 0;
+		new_domain = group->blocking_domain;
 	}
 
 	/*
-- 
2.25.1