[PATCH 5/6] iommu: remove IOMMU_DEV_FEAT_AUX

[Christoph Hellwig <hch@lst.de>]

This feature is entirely unused, and was only ever called by unused code
either.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/iommu/intel/iommu.c | 82 -------------------------------------
 drivers/iommu/intel/svm.c   |  6 ---
 include/linux/intel-iommu.h |  1 -
 include/linux/iommu.h       |  2 -
 4 files changed, 91 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 6cae6e4d693226..2603d95ecb4c0e 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2573,7 +2573,6 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 	info->domain = domain;
 	info->iommu = iommu;
 	info->pasid_table = NULL;
-	info->auxd_enabled = 0;
 
 	if (dev && dev_is_pci(dev)) {
 		struct pci_dev *pdev = to_pci_dev(info->dev);
@@ -4546,19 +4545,6 @@ static void intel_iommu_domain_free(struct iommu_domain *domain)
 		domain_exit(to_dmar_domain(domain));
 }
 
-/*
- * Check whether a @domain could be attached to the @dev through the
- * aux-domain attach/detach APIs.
- */
-static inline bool
-is_aux_domain(struct device *dev, struct iommu_domain *domain)
-{
-	struct device_domain_info *info = get_domain_info(dev);
-
-	return info && info->auxd_enabled &&
-			domain->type == IOMMU_DOMAIN_UNMANAGED;
-}
-
 static int prepare_domain_attach_device(struct iommu_domain *domain,
 					struct device *dev)
 {
@@ -4612,9 +4598,6 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
 		return -EPERM;
 	}
 
-	if (is_aux_domain(dev, domain))
-		return -EPERM;
-
 	/* normally dev is not mapped */
 	if (unlikely(domain_context_mapped(dev))) {
 		struct dmar_domain *old_domain;
@@ -5083,52 +5066,9 @@ static struct iommu_group *intel_iommu_device_group(struct device *dev)
 	return generic_device_group(dev);
 }
 
-static int intel_iommu_enable_auxd(struct device *dev)
-{
-	struct device_domain_info *info;
-	struct intel_iommu *iommu;
-	unsigned long flags;
-	int ret;
-
-	iommu = device_to_iommu(dev, NULL, NULL);
-	if (!iommu || dmar_disabled)
-		return -EINVAL;
-
-	if (!sm_supported(iommu) || !pasid_supported(iommu))
-		return -EINVAL;
-
-	ret = intel_iommu_enable_pasid(iommu, dev);
-	if (ret)
-		return -ENODEV;
-
-	spin_lock_irqsave(&device_domain_lock, flags);
-	info = get_domain_info(dev);
-	info->auxd_enabled = 1;
-	spin_unlock_irqrestore(&device_domain_lock, flags);
-
-	return 0;
-}
-
-static int intel_iommu_disable_auxd(struct device *dev)
-{
-	struct device_domain_info *info;
-	unsigned long flags;
-
-	spin_lock_irqsave(&device_domain_lock, flags);
-	info = get_domain_info(dev);
-	if (!WARN_ON(!info))
-		info->auxd_enabled = 0;
-	spin_unlock_irqrestore(&device_domain_lock, flags);
-
-	return 0;
-}
-
 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) {
 		struct device_domain_info *info = get_domain_info(dev);
 
@@ -5152,26 +5092,6 @@ intel_iommu_dev_enable_feat(struct device *dev, enum iommu_dev_features feat)
 	return -ENODEV;
 }
 
-static int
-intel_iommu_dev_disable_feat(struct device *dev, enum iommu_dev_features feat)
-{
-	if (feat == IOMMU_DEV_FEAT_AUX)
-		return intel_iommu_disable_auxd(dev);
-
-	return -ENODEV;
-}
-
-static bool
-intel_iommu_dev_feat_enabled(struct device *dev, enum iommu_dev_features feat)
-{
-	struct device_domain_info *info = get_domain_info(dev);
-
-	if (feat == IOMMU_DEV_FEAT_AUX)
-		return scalable_mode_support() && info && info->auxd_enabled;
-
-	return false;
-}
-
 static bool intel_iommu_is_attach_deferred(struct iommu_domain *domain,
 					   struct device *dev)
 {
@@ -5283,9 +5203,7 @@ 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_feat_enabled	= intel_iommu_dev_feat_enabled,
 	.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		= INTEL_IOMMU_PGSIZES,
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 5165cea904211a..54b55f867438c8 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -347,10 +347,6 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
 	sdev->sid = PCI_DEVID(info->bus, info->devfn);
 	sdev->iommu = iommu;
 
-	/* Only count users if device has aux domains */
-	if (iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX))
-		sdev->users = 1;
-
 	/* Set up device context entry for PASID if not enabled already */
 	ret = intel_iommu_enable_pasid(iommu, sdev->dev);
 	if (ret) {
@@ -412,8 +408,6 @@ int intel_svm_unbind_gpasid(struct device *dev, u32 pasid)
 		goto out;
 
 	if (sdev) {
-		if (iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX))
-			sdev->users--;
 		if (!sdev->users) {
 			list_del_rcu(&sdev->list);
 			intel_pasid_tear_down_entry(iommu, dev,
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index c12b8e6545733c..4b855c42435f7c 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -636,7 +636,6 @@ struct device_domain_info {
 	u8 pri_enabled:1;
 	u8 ats_supported:1;
 	u8 ats_enabled:1;
-	u8 auxd_enabled:1;	/* Multiple domains per device */
 	u8 ats_qdep;
 	struct device *dev; /* it's NULL for PCIe-to-PCI bridge */
 	struct intel_iommu *iommu; /* IOMMU used by this device */
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index b0bf99dfd80d16..ef9e7dcef76e90 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -132,7 +132,6 @@ struct iommu_resv_region {
 
 /**
  * enum iommu_dev_features - Per device IOMMU features
- * @IOMMU_DEV_FEAT_AUX: Auxiliary domain feature
  * @IOMMU_DEV_FEAT_SVA: Shared Virtual Addresses
  * @IOMMU_DEV_FEAT_IOPF: I/O Page Faults such as PRI or Stall. Generally
  *			 enabling %IOMMU_DEV_FEAT_SVA requires
@@ -144,7 +143,6 @@ struct iommu_resv_region {
  * Device drivers enable a feature using iommu_dev_enable_feature().
  */
 enum iommu_dev_features {
-	IOMMU_DEV_FEAT_AUX,
 	IOMMU_DEV_FEAT_SVA,
 	IOMMU_DEV_FEAT_IOPF,
 };
-- 
2.30.2