dmaengine: idxd: Remove unnecessary IOMMU_DEV_FEAT_IOPF

The IOMMU_DEV_FEAT_IOPF implementation in the iommu driver is just a no-op.
It will also be removed from the iommu driver in the subsequent patch.
Remove it to avoid dead code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Link: https://lore.kernel.org/r/20250418080130.1844424-6-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Author: LuBaolu

drivers/dma/idxd/init.c

@@ -626,21 +626,6 @@ static void idxd_disable_system_pasid(struct idxd_device *idxd)
 	idxd->pasid = IOMMU_PASID_INVALID;
 }
 
-static int idxd_enable_sva(struct pci_dev *pdev)
-{
-	int ret;
-
-	ret = iommu_dev_enable_feature(&pdev->dev, IOMMU_DEV_FEAT_IOPF);
-	if (ret)
-		return ret;
-	return 0;
-}
-
-static void idxd_disable_sva(struct pci_dev *pdev)
-{
-	iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_IOPF);
-}
-
 static int idxd_probe(struct idxd_device *idxd)
 {
 	struct pci_dev *pdev = idxd->pdev;
@@ -655,17 +640,13 @@ static int idxd_probe(struct idxd_device *idxd)
 	dev_dbg(dev, "IDXD reset complete\n");
 
 	if (IS_ENABLED(CONFIG_INTEL_IDXD_SVM) && sva) {
-		if (idxd_enable_sva(pdev)) {
-			dev_warn(dev, "Unable to turn on user SVA feature.\n");
-		} else {
-			set_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags);
+		set_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags);
 
-			rc = idxd_enable_system_pasid(idxd);
-			if (rc)
-				dev_warn(dev, "No in-kernel DMA with PASID. %d\n", rc);
-			else
-				set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
-		}
+		rc = idxd_enable_system_pasid(idxd);
+		if (rc)
+			dev_warn(dev, "No in-kernel DMA with PASID. %d\n", rc);
+		else
+			set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
 	} else if (!sva) {
 		dev_warn(dev, "User forced SVA off via module param.\n");
 	}
@@ -703,8 +684,6 @@ static int idxd_probe(struct idxd_device *idxd)
  err:
 	if (device_pasid_enabled(idxd))
 		idxd_disable_system_pasid(idxd);
-	if (device_user_pasid_enabled(idxd))
-		idxd_disable_sva(pdev);
 	return rc;
 }
 
@@ -715,8 +694,6 @@ static void idxd_cleanup(struct idxd_device *idxd)
 	idxd_cleanup_internals(idxd);
 	if (device_pasid_enabled(idxd))
 		idxd_disable_system_pasid(idxd);
-	if (device_user_pasid_enabled(idxd))
-		idxd_disable_sva(idxd->pdev);
 }
 
 /*
@@ -1247,8 +1224,6 @@ static void idxd_remove(struct pci_dev *pdev)
 	free_irq(irq_entry->vector, irq_entry);
 	pci_free_irq_vectors(pdev);
 	pci_iounmap(pdev, idxd->reg_base);
-	if (device_user_pasid_enabled(idxd))
-		idxd_disable_sva(pdev);
 	pci_disable_device(pdev);
 	destroy_workqueue(idxd->wq);
 	perfmon_pmu_remove(idxd);