iommu: Remove aux-domain related interfaces and iommu_ops

The aux-domain related interfaces and iommu_ops are not referenced
anywhere in the tree. We've also reached a consensus to redesign it
based the new iommufd framework. Remove them to avoid dead code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220216025249.3459465-5-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/iommu.c

@@ -2749,8 +2749,6 @@ EXPORT_SYMBOL_GPL(iommu_dev_enable_feature);
 
 /*
  * The device drivers should do the necessary cleanups before calling this.
- * For example, before disabling the aux-domain feature, the device driver
- * should detach all aux-domains. Otherwise, this will return -EBUSY.
  */
 int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat)
 {
@@ -2778,50 +2776,6 @@ bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat)
 }
 EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled);
 
-/*
- * Aux-domain specific attach/detach.
- *
- * Only works if iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX) returns
- * true. Also, as long as domains are attached to a device through this
- * interface, any tries to call iommu_attach_device() should fail
- * (iommu_detach_device() can't fail, so we fail when trying to re-attach).
- * This should make us safe against a device being attached to a guest as a
- * whole while there are still pasid users on it (aux and sva).
- */
-int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev)
-{
-	int ret = -ENODEV;
-
-	if (domain->ops->aux_attach_dev)
-		ret = domain->ops->aux_attach_dev(domain, dev);
-
-	if (!ret)
-		trace_attach_device_to_domain(dev);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(iommu_aux_attach_device);
-
-void iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev)
-{
-	if (domain->ops->aux_detach_dev) {
-		domain->ops->aux_detach_dev(domain, dev);
-		trace_detach_device_from_domain(dev);
-	}
-}
-EXPORT_SYMBOL_GPL(iommu_aux_detach_device);
-
-int iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev)
-{
-	int ret = -ENODEV;
-
-	if (domain->ops->aux_get_pasid)
-		ret = domain->ops->aux_get_pasid(domain, dev);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(iommu_aux_get_pasid);
-
 /**
  * iommu_sva_bind_device() - Bind a process address space to a device
  * @dev: the device

include/linux/iommu.h

@@ -144,7 +144,6 @@ struct iommu_resv_region {
 
 /**
  * enum iommu_dev_features - Per device IOMMU features
- * @IOMMU_DEV_FEAT_AUX: Auxiliary domain feature
  * @IOMMU_DEV_FEAT_SVA: Shared Virtual Addresses
  * @IOMMU_DEV_FEAT_IOPF: I/O Page Faults such as PRI or Stall. Generally
  *			 enabling %IOMMU_DEV_FEAT_SVA requires
@@ -157,7 +156,6 @@ struct iommu_resv_region {
  * iommu_dev_has_feature(), and enable it using iommu_dev_enable_feature().
  */
 enum iommu_dev_features {
-	IOMMU_DEV_FEAT_AUX,
 	IOMMU_DEV_FEAT_SVA,
 	IOMMU_DEV_FEAT_IOPF,
 };
@@ -223,8 +221,6 @@ struct iommu_iotlb_gather {
  * @dev_has/enable/disable_feat: per device entries to check/enable/disable
  *                               iommu specific features.
  * @dev_feat_enabled: check enabled feature
- * @aux_attach/detach_dev: aux-domain specific attach/detach entries.
- * @aux_get_pasid: get the pasid given an aux-domain
  * @sva_bind: Bind process address space to device
  * @sva_unbind: Unbind process address space from device
  * @sva_get_pasid: Get PASID associated to a SVA handle
@@ -285,11 +281,6 @@ struct iommu_ops {
 	int (*dev_enable_feat)(struct device *dev, enum iommu_dev_features f);
 	int (*dev_disable_feat)(struct device *dev, enum iommu_dev_features f);
 
-	/* Aux-domain specific attach/detach entries */
-	int (*aux_attach_dev)(struct iommu_domain *domain, struct device *dev);
-	void (*aux_detach_dev)(struct iommu_domain *domain, struct device *dev);
-	int (*aux_get_pasid)(struct iommu_domain *domain, struct device *dev);
-
 	struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct *mm,
 				      void *drvdata);
 	void (*sva_unbind)(struct iommu_sva *handle);
@@ -655,9 +646,6 @@ void iommu_release_device(struct device *dev);
 int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f);
 int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features f);
 bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features f);
-int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev);
-void iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev);
-int iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev);
 
 struct iommu_sva *iommu_sva_bind_device(struct device *dev,
 					struct mm_struct *mm,
@@ -1002,23 +990,6 @@ iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat)
 	return -ENODEV;
 }
 
-static inline int
-iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev)
-{
-	return -ENODEV;
-}
-
-static inline void
-iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev)
-{
-}
-
-static inline int
-iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev)
-{
-	return -ENODEV;
-}
-
 static inline struct iommu_sva *
 iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
 {