[PATCH 1/6] iommu: remove the unused dev_has_feat method

Christoph Hellwig
2021-05-10T06:54:35Z

This method is never actually called. Simplify the instance in
intel-iommu that is directly called by inlining the relevant code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 1 -
drivers/iommu/intel/iommu.c | 67 ++-------------------
include/linux/iommu.h | 4 +-
3 files changed, 7 insertions(+), 65 deletions(-)

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 54b2f27b81d439..9689563eec0f30 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2666,7 +2666,6 @@ 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,
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 708f430af1c440..ba1060f6785119 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -5326,72 +5326,18 @@ static int intel_iommu_disable_auxd(struct device *dev)
return 0;
}

-/*
- * A PCI express designated vendor specific extended capability is defined
- * in the section 3.7 of Intel scalable I/O virtualization technical spec
- * for system software and tools to detect endpoint devices supporting the
- * Intel scalable IO virtualization without host driver dependency.
- *
- * Returns the address of the matching extended capability structure within
- * the device's PCI configuration space or 0 if the device does not support
- * it.
- */
-static int siov_find_pci_dvsec(struct pci_dev *pdev)
-{
- int pos;
- u16 vendor, id;
-
- pos = pci_find_next_ext_capability(pdev, 0, 0x23);
- while (pos) {
- pci_read_config_word(pdev, pos + 4, &vendor);
- pci_read_config_word(pdev, pos + 8, &id);
- if (vendor == PCI_VENDOR_ID_INTEL && id == 5)
- return pos;
-
- pos = pci_find_next_ext_capability(pdev, pos, 0x23);
- }
-
- return 0;
-}
-
-static bool
-intel_iommu_dev_has_feat(struct device *dev, enum iommu_dev_features feat)
-{
- struct device_domain_info *info = get_domain_info(dev);
-
- if (feat == IOMMU_DEV_FEAT_AUX) {
- int ret;
-
- if (!dev_is_pci(dev) || dmar_disabled ||
- !scalable_mode_support() || !pasid_mode_support())
- return false;
-
- ret = pci_pasid_features(to_pci_dev(dev));
- if (ret < 0)
- return false;
-
- return !!siov_find_pci_dvsec(to_pci_dev(dev));
- }
-
- if (feat == IOMMU_DEV_FEAT_IOPF)
- return info && info->pri_supported;
-
- if (feat == IOMMU_DEV_FEAT_SVA)
- return info && (info->iommu->flags & VTD_FLAG_SVM_CAPABLE) &&
- info->pasid_supported && info->pri_supported &&
- info->ats_supported;
-
- return false;
-}
-
static int
intel_iommu_dev_enable_feat(struct device *dev, enum iommu_dev_features feat)
{
if (feat == IOMMU_DEV_FEAT_AUX)
return intel_iommu_enable_auxd(dev);

- if (feat == IOMMU_DEV_FEAT_IOPF)
- return intel_iommu_dev_has_feat(dev, feat) ? 0 : -ENODEV;
+ if (feat == IOMMU_DEV_FEAT_IOPF) {
+ struct device_domain_info *info = get_domain_info(dev);
+
+ if (info && info->pri_supported)
+ return 0;
+ }

if (feat == IOMMU_DEV_FEAT_SVA) {
struct device_domain_info *info = get_domain_info(dev);
@@ -5552,7 +5498,6 @@ const struct iommu_ops intel_iommu_ops = {
.get_resv_regions = intel_iommu_get_resv_regions,
.put_resv_regions = generic_iommu_put_resv_regions,
.device_group = intel_iommu_device_group,
- .dev_has_feat = intel_iommu_dev_has_feat,
.dev_feat_enabled = intel_iommu_dev_feat_enabled,
.dev_enable_feat = intel_iommu_dev_enable_feat,
.dev_disable_feat = intel_iommu_dev_disable_feat,
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 32d448050bf76e..1092a7f967a5e8 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -141,8 +141,7 @@ struct iommu_resv_region {
* 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_AUX,
@@ -256,7 +255,6 @@ struct iommu_ops {
bool (*is_attach_deferred)(struct iommu_domain *domain, 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);
--
2.30.2