iommu: Remove iommu_dev_enable/disable_feature()

No external drivers use these interfaces anymore. Furthermore, no existing
iommu drivers implement anything in the callbacks. Remove them to avoid
dead code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20250418080130.1844424-9-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Author: LuBaolu

drivers/iommu/amd/iommu.c

@@ -2984,36 +2984,6 @@ static const struct iommu_dirty_ops amd_dirty_ops = {
 	.read_and_clear_dirty = amd_iommu_read_and_clear_dirty,
 };
 
-static int amd_iommu_dev_enable_feature(struct device *dev,
-					enum iommu_dev_features feat)
-{
-	int ret = 0;
-
-	switch (feat) {
-	case IOMMU_DEV_FEAT_IOPF:
-		break;
-	default:
-		ret = -EINVAL;
-		break;
-	}
-	return ret;
-}
-
-static int amd_iommu_dev_disable_feature(struct device *dev,
-					 enum iommu_dev_features feat)
-{
-	int ret = 0;
-
-	switch (feat) {
-	case IOMMU_DEV_FEAT_IOPF:
-		break;
-	default:
-		ret = -EINVAL;
-		break;
-	}
-	return ret;
-}
-
 const struct iommu_ops amd_iommu_ops = {
 	.capable = amd_iommu_capable,
 	.blocked_domain = &blocked_domain,
@@ -3027,8 +2997,6 @@ const struct iommu_ops amd_iommu_ops = {
 	.get_resv_regions = amd_iommu_get_resv_regions,
 	.is_attach_deferred = amd_iommu_is_attach_deferred,
 	.def_domain_type = amd_iommu_def_domain_type,
-	.dev_enable_feat = amd_iommu_dev_enable_feature,
-	.dev_disable_feat = amd_iommu_dev_disable_feature,
 	.page_response = amd_iommu_page_response,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= amd_iommu_attach_device,

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

@@ -3643,38 +3643,6 @@ static void arm_smmu_get_resv_regions(struct device *dev,
 	iommu_dma_get_resv_regions(dev, head);
 }
 
-static int arm_smmu_dev_enable_feature(struct device *dev,
-				       enum iommu_dev_features feat)
-{
-	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
-
-	if (!master)
-		return -ENODEV;
-
-	switch (feat) {
-	case IOMMU_DEV_FEAT_IOPF:
-		return 0;
-	default:
-		return -EINVAL;
-	}
-}
-
-static int arm_smmu_dev_disable_feature(struct device *dev,
-					enum iommu_dev_features feat)
-{
-	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
-
-	if (!master)
-		return -EINVAL;
-
-	switch (feat) {
-	case IOMMU_DEV_FEAT_IOPF:
-		return 0;
-	default:
-		return -EINVAL;
-	}
-}
-
 /*
  * HiSilicon PCIe tune and trace device can be used to trace TLP headers on the
  * PCIe link and save the data to memory by DMA. The hardware is restricted to
@@ -3707,8 +3675,6 @@ static struct iommu_ops arm_smmu_ops = {
 	.device_group		= arm_smmu_device_group,
 	.of_xlate		= arm_smmu_of_xlate,
 	.get_resv_regions	= arm_smmu_get_resv_regions,
-	.dev_enable_feat	= arm_smmu_dev_enable_feature,
-	.dev_disable_feat	= arm_smmu_dev_disable_feature,
 	.page_response		= arm_smmu_page_response,
 	.def_domain_type	= arm_smmu_def_domain_type,
 	.viommu_alloc		= arm_vsmmu_alloc,

drivers/iommu/intel/iommu.c

@@ -3957,29 +3957,6 @@ void intel_iommu_disable_iopf(struct device *dev)
 	iopf_queue_remove_device(iommu->iopf_queue, dev);
 }
 
-static int
-intel_iommu_dev_enable_feat(struct device *dev, enum iommu_dev_features feat)
-{
-	switch (feat) {
-	case IOMMU_DEV_FEAT_IOPF:
-		return 0;
-	default:
-		return -ENODEV;
-	}
-}
-
-static int
-intel_iommu_dev_disable_feat(struct device *dev, enum iommu_dev_features feat)
-{
-	switch (feat) {
-	case IOMMU_DEV_FEAT_IOPF:
-		return 0;
-
-	default:
-		return -ENODEV;
-	}
-}
-
 static bool intel_iommu_is_attach_deferred(struct device *dev)
 {
 	struct device_domain_info *info = dev_iommu_priv_get(dev);
@@ -4421,8 +4398,6 @@ const struct iommu_ops intel_iommu_ops = {
 	.release_device		= intel_iommu_release_device,
 	.get_resv_regions	= intel_iommu_get_resv_regions,
 	.device_group		= intel_iommu_device_group,
-	.dev_enable_feat	= intel_iommu_dev_enable_feat,
-	.dev_disable_feat	= intel_iommu_dev_disable_feat,
 	.is_attach_deferred	= intel_iommu_is_attach_deferred,
 	.def_domain_type	= device_def_domain_type,
 	.pgsize_bitmap		= SZ_4K,

drivers/iommu/iommu.c

@@ -2910,38 +2910,6 @@ int iommu_fwspec_add_ids(struct device *dev, const u32 *ids, int num_ids)
 }
 EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids);
 
-/*
- * Per device IOMMU features.
- */
-int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat)
-{
-	if (dev_has_iommu(dev)) {
-		const struct iommu_ops *ops = dev_iommu_ops(dev);
-
-		if (ops->dev_enable_feat)
-			return ops->dev_enable_feat(dev, feat);
-	}
-
-	return -ENODEV;
-}
-EXPORT_SYMBOL_GPL(iommu_dev_enable_feature);
-
-/*
- * The device drivers should do the necessary cleanups before calling this.
- */
-int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat)
-{
-	if (dev_has_iommu(dev)) {
-		const struct iommu_ops *ops = dev_iommu_ops(dev);
-
-		if (ops->dev_disable_feat)
-			return ops->dev_disable_feat(dev, feat);
-	}
-
-	return -EBUSY;
-}
-EXPORT_SYMBOL_GPL(iommu_dev_disable_feature);
-
 /**
  * iommu_setup_default_domain - Set the default_domain for the group
  * @group: Group to change

include/linux/iommu.h

@@ -316,16 +316,6 @@ struct iommu_iort_rmr_data {
 	u32 num_sids;
 };
 
-/**
- * enum iommu_dev_features - Per device IOMMU features
- * @IOMMU_DEV_FEAT_IOPF: I/O Page Faults such as PRI or Stall.
- *
- * Device drivers enable a feature using iommu_dev_enable_feature().
- */
-enum iommu_dev_features {
-	IOMMU_DEV_FEAT_IOPF,
-};
-
 #define IOMMU_NO_PASID	(0U) /* Reserved for DMA w/o PASID */
 #define IOMMU_FIRST_GLOBAL_PASID	(1U) /*starting range for allocation */
 #define IOMMU_PASID_INVALID	(-1U)
@@ -657,9 +647,6 @@ struct iommu_ops {
 	bool (*is_attach_deferred)(struct device *dev);
 
 	/* Per device IOMMU features */
-	int (*dev_enable_feat)(struct device *dev, enum iommu_dev_features f);
-	int (*dev_disable_feat)(struct device *dev, enum iommu_dev_features f);
-
 	void (*page_response)(struct device *dev, struct iopf_fault *evt,
 			      struct iommu_page_response *msg);
 
@@ -1128,9 +1115,6 @@ void dev_iommu_priv_set(struct device *dev, void *priv);
 extern struct mutex iommu_probe_device_lock;
 int iommu_probe_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);
-
 int iommu_device_use_default_domain(struct device *dev);
 void iommu_device_unuse_default_domain(struct device *dev);
 
@@ -1415,18 +1399,6 @@ static inline int iommu_fwspec_add_ids(struct device *dev, u32 *ids,
 	return -ENODEV;
 }
 
-static inline int
-iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat)
-{
-	return -ENODEV;
-}
-
-static inline int
-iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat)
-{
-	return -ENODEV;
-}
-
 static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev)
 {
 	return NULL;