iommu: remove the unused dev_has_feat method

This method is never actually called.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20220708080616.238833-2-hch@lst.deSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

@@ -2853,7 +2853,6 @@ static struct iommu_ops arm_smmu_ops = {
 	.of_xlate		= arm_smmu_of_xlate,
 	.get_resv_regions	= arm_smmu_get_resv_regions,
 	.put_resv_regions	= generic_iommu_put_resv_regions,
-	.dev_has_feat		= arm_smmu_dev_has_feature,
 	.dev_feat_enabled	= arm_smmu_dev_feature_enabled,
 	.dev_enable_feat	= arm_smmu_dev_enable_feature,
 	.dev_disable_feat	= arm_smmu_dev_disable_feature,

include/linux/iommu.h

@@ -164,8 +164,7 @@ struct iommu_iort_rmr_data {
  *			 supported, this feature must be enabled before and
  *			 disabled after %IOMMU_DEV_FEAT_SVA.
  *
- * Device drivers query whether a feature is supported using
- * iommu_dev_has_feature(), and enable it using iommu_dev_enable_feature().
+ * Device drivers enable a feature using iommu_dev_enable_feature().
  */
 enum iommu_dev_features {
 	IOMMU_DEV_FEAT_SVA,
@@ -248,7 +247,6 @@ struct iommu_ops {
 	bool (*is_attach_deferred)(struct device *dev);
 
 	/* Per device IOMMU features */
-	bool (*dev_has_feat)(struct device *dev, enum iommu_dev_features f);
 	bool (*dev_feat_enabled)(struct device *dev, enum iommu_dev_features f);
 	int (*dev_enable_feat)(struct device *dev, enum iommu_dev_features f);
 	int (*dev_disable_feat)(struct device *dev, enum iommu_dev_features f);