[PATCH v5 8/8] iommu: Remove iommu_dev_enable/disable_feature()

Lu Baolu
2025-04-18T08:01:29Z

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>
---
drivers/iommu/amd/iommu.c | 32 -------------------
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 34 ---------------------
drivers/iommu/intel/iommu.c | 25 ---------------
drivers/iommu/iommu.c | 32 -------------------
include/linux/iommu.h | 28 -----------------
5 files changed, 151 deletions(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 17aab6d04a13..a9d539fce982 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/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,
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 73f9885d20f1..e91d20e5785e 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3654,38 +3654,6 @@ 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
@@ -3718,8 +3686,6 @@ 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,
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 9af558390d42..93bc6574d148 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3963,29 +3963,6 @@ 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);
@@ -4428,8 +4405,6 @@ 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,
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 264383b507bc..df283bddf6cd 100644
--- a/drivers/iommu/iommu.c
+++ b/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
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index bfdd2e71e124..5c05c0851f9f 100644
--- a/include/linux/iommu.h
+++ b/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;
--
2.43.0