iommu: Delete iommu_dev_has_feature()

Function iommu_dev_has_feature() has never been referenced in the tree,
and there does not appear to be anything coming soon to use it, so delete
it.

Signed-off-by: John Garry <john.garry@huawei.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/1609940111-28563-7-git-send-email-john.garry@huawei.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Author: John Garry

drivers/iommu/iommu.c

@@ -2853,17 +2853,6 @@ EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids);
 /*
  * Per device IOMMU features.
  */
-bool iommu_dev_has_feature(struct device *dev, enum iommu_dev_features feat)
-{
-	const struct iommu_ops *ops = dev->bus->iommu_ops;
-
-	if (ops && ops->dev_has_feat)
-		return ops->dev_has_feat(dev, feat);
-
-	return false;
-}
-EXPORT_SYMBOL_GPL(iommu_dev_has_feature);
-
 int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat)
 {
 	const struct iommu_ops *ops = dev->bus->iommu_ops;

include/linux/iommu.h

@@ -626,7 +626,6 @@ static inline void dev_iommu_priv_set(struct device *dev, void *priv)
 int iommu_probe_device(struct device *dev);
 void iommu_release_device(struct device *dev);
 
-bool iommu_dev_has_feature(struct device *dev, enum iommu_dev_features f);
 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);
@@ -975,12 +974,6 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode)
 	return NULL;
 }
 
-static inline bool
-iommu_dev_has_feature(struct device *dev, enum iommu_dev_features feat)
-{
-	return false;
-}
-
 static inline bool
 iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat)
 {