[RFC,07/12] iommu/vt-d: Retire struct intel_svm

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index bd7210980fb2..a9e9301b2713 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -860,13 +860,6 @@  int intel_svm_page_response(struct device *dev, struct iommu_fault_event *evt,
 struct iommu_domain *intel_svm_domain_alloc(void);
 void intel_svm_remove_dev_pasid(struct device *dev, ioasid_t pasid);
 void intel_drain_pasid_prq(struct device *dev, u32 pasid);
-
-struct intel_svm {
-	struct mmu_notifier notifier;
-	struct mm_struct *mm;
-	u32 pasid;
-	struct list_head devs;
-};
 #else
 static inline void intel_svm_check(struct intel_iommu *iommu) {}
 static inline void intel_drain_pasid_prq(struct device *dev, u32 pasid) {}
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index e0373586811e..fd61fbf7593a 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -27,30 +27,13 @@ 
 
 static irqreturn_t prq_event_thread(int irq, void *d);
 
-static DEFINE_XARRAY_ALLOC(pasid_private_array);
-static int pasid_private_add(ioasid_t pasid, void *priv)
-{
-	return xa_alloc(&pasid_private_array, &pasid, priv,
-			XA_LIMIT(pasid, pasid), GFP_ATOMIC);
-}
-
-static void pasid_private_remove(ioasid_t pasid)
-{
-	xa_erase(&pasid_private_array, pasid);
-}
-
-static void *pasid_private_find(ioasid_t pasid)
-{
-	return xa_load(&pasid_private_array, pasid);
-}
-
 static struct dev_pasid_info *
-svm_lookup_dev_pasid_info_by_dev(struct intel_svm *svm, struct device *dev)
+domain_lookup_dev_pasid_info_by_dev(struct dmar_domain *domain, struct device *dev)
 {
 	struct dev_pasid_info *dev_pasid = NULL, *t;
 
 	rcu_read_lock();
-	list_for_each_entry_rcu(t, &svm->devs, link_domain) {
+	list_for_each_entry_rcu(t, &domain->dev_pasids, link_domain) {
 		if (t->dev == dev) {
 			dev_pasid = t;
 			break;
@@ -169,28 +152,29 @@  void intel_svm_check(struct intel_iommu *iommu)
 	iommu->flags |= VTD_FLAG_SVM_CAPABLE;
 }
 
-static void __flush_svm_range_dev(struct intel_svm *svm,
+static void __flush_svm_range_dev(struct dmar_domain *domain,
 				  struct dev_pasid_info *dev_pasid,
 				  unsigned long address,
 				  unsigned long pages, int ih)
 {
 	struct device_domain_info *info = dev_iommu_priv_get(dev_pasid->dev);
 	struct intel_iommu *iommu = dev_to_intel_iommu(dev_pasid->dev);
+	u32 pasid = mm_get_enqcmd_pasid(domain->domain.mm);
 
 	if (WARN_ON(!pages))
 		return;
 
-	qi_flush_piotlb(iommu, FLPT_DEFAULT_DID, svm->pasid, address, pages, ih);
+	qi_flush_piotlb(iommu, FLPT_DEFAULT_DID, pasid, address, pages, ih);
 	if (info->ats_enabled) {
 		qi_flush_dev_iotlb_pasid(iommu, dev_pasid->sid, info->pfsid,
-					 svm->pasid, dev_pasid->qdep, address,
+					 pasid, dev_pasid->qdep, address,
 					 order_base_2(pages));
 		quirk_extra_dev_tlb_flush(info, address, order_base_2(pages),
-					  svm->pasid, dev_pasid->qdep);
+					  pasid, dev_pasid->qdep);
 	}
 }
 
-static void intel_flush_svm_range_dev(struct intel_svm *svm,
+static void intel_flush_svm_range_dev(struct dmar_domain *domain,
 				      struct dev_pasid_info *dev_pasid,
 				      unsigned long address,
 				      unsigned long pages, int ih)
@@ -201,19 +185,19 @@  static void intel_flush_svm_range_dev(struct intel_svm *svm,
 	unsigned long end = ALIGN(address + (pages << VTD_PAGE_SHIFT), align);
 
 	while (start < end) {
-		__flush_svm_range_dev(svm, dev_pasid, start, align >> VTD_PAGE_SHIFT, ih);
+		__flush_svm_range_dev(domain, dev_pasid, start, align >> VTD_PAGE_SHIFT, ih);
 		start += align;
 	}
 }
 
-static void intel_flush_svm_range(struct intel_svm *svm, unsigned long address,
+static void intel_flush_svm_range(struct dmar_domain *domain, unsigned long address,
 				unsigned long pages, int ih)
 {
 	struct dev_pasid_info *dev_pasid;
 
 	rcu_read_lock();
-	list_for_each_entry_rcu(dev_pasid, &svm->devs, link_domain)
-		intel_flush_svm_range_dev(svm, dev_pasid, address, pages, ih);
+	list_for_each_entry_rcu(dev_pasid, &domain->dev_pasids, link_domain)
+		intel_flush_svm_range_dev(domain, dev_pasid, address, pages, ih);
 	rcu_read_unlock();
 }
 
@@ -222,15 +206,15 @@  static void intel_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
 					struct mm_struct *mm,
 					unsigned long start, unsigned long end)
 {
-	struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
+	struct iommu_domain *domain = container_of(mn, struct iommu_domain, notifier);
 
-	intel_flush_svm_range(svm, start,
+	intel_flush_svm_range(to_dmar_domain(domain), start,
 			      (end - start + PAGE_SIZE - 1) >> VTD_PAGE_SHIFT, 0);
 }
 
 static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
 {
-	struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
+	struct iommu_domain *domain = container_of(mn, struct iommu_domain, notifier);
 	struct dev_pasid_info *dev_pasid;
 	struct intel_iommu *iommu;
 
@@ -247,10 +231,10 @@  static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
 	 * *has* to handle gracefully without affecting other processes.
 	 */
 	rcu_read_lock();
-	list_for_each_entry_rcu(dev_pasid, &svm->devs, link_domain) {
+	list_for_each_entry_rcu(dev_pasid, &to_dmar_domain(domain)->dev_pasids, link_domain) {
 		iommu = dev_to_intel_iommu(dev_pasid->dev);
 		intel_pasid_tear_down_entry(iommu, dev_pasid->dev,
-					    svm->pasid, true);
+					    mm_get_enqcmd_pasid(domain->mm), true);
 	}
 	rcu_read_unlock();
 
@@ -261,78 +245,32 @@  static const struct mmu_notifier_ops intel_mmuops = {
 	.arch_invalidate_secondary_tlbs = intel_arch_invalidate_secondary_tlbs,
 };
 
-static int pasid_to_dev_pasid_info(struct device *dev, unsigned int pasid,
-			     struct intel_svm **rsvm,
-			     struct dev_pasid_info **rsdev_pasid_info)
-{
-	struct dev_pasid_info *dev_pasid = NULL;
-	struct intel_svm *svm;
-
-	if (pasid == IOMMU_PASID_INVALID || pasid >= PASID_MAX)
-		return -EINVAL;
-
-	svm = pasid_private_find(pasid);
-	if (IS_ERR(svm))
-		return PTR_ERR(svm);
-
-	if (!svm)
-		goto out;
-
-	/*
-	 * If we found svm for the PASID, there must be at least one device
-	 * bond.
-	 */
-	if (WARN_ON(list_empty(&svm->devs)))
-		return -EINVAL;
-	dev_pasid = svm_lookup_dev_pasid_info_by_dev(svm, dev);
-
-out:
-	*rsvm = svm;
-	*rsdev_pasid_info = dev_pasid;
-
-	return 0;
-}
-
 static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
 				   struct device *dev, ioasid_t pasid)
 {
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
 	struct device_domain_info *info = dev_iommu_priv_get(dev);
 	struct intel_iommu *iommu = info->iommu;
 	struct mm_struct *mm = domain->mm;
 	struct dev_pasid_info *dev_pasid;
-	struct intel_svm *svm;
 	unsigned long sflags;
 	int ret = 0;
 
-	svm = pasid_private_find(pasid);
-	if (!svm) {
-		svm = kzalloc(sizeof(*svm), GFP_KERNEL);
-		if (!svm)
-			return -ENOMEM;
-
-		svm->pasid = pasid;
-		svm->mm = mm;
-		INIT_LIST_HEAD_RCU(&svm->devs);
-
-		svm->notifier.ops = &intel_mmuops;
-		ret = mmu_notifier_register(&svm->notifier, mm);
-		if (ret) {
-			kfree(svm);
-			return ret;
-		}
-
-		ret = pasid_private_add(svm->pasid, svm);
-		if (ret) {
-			mmu_notifier_unregister(&svm->notifier, mm);
-			kfree(svm);
+	/*
+	 * The sva domain can be shared among multiple devices. Make sure
+	 * to add the notifier only once to a sva domain.
+	 */
+	if (domain->notifier.ops != &intel_mmuops) {
+		domain->notifier.ops = &intel_mmuops;
+		ret = mmu_notifier_register(&domain->notifier, mm);
+		if (ret)
 			return ret;
-		}
 	}
 
 	dev_pasid = kzalloc(sizeof(*dev_pasid), GFP_KERNEL);
 	if (!dev_pasid) {
 		ret = -ENOMEM;
-		goto free_svm;
+		goto out_unregister;
 	}
 
 	dev_pasid->dev = dev;
@@ -348,46 +286,39 @@  static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
 	ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, pasid,
 					    FLPT_DEFAULT_DID, sflags);
 	if (ret)
-		goto free_dev_pasid;
+		goto out_free_dev_pasid;
 
-	list_add_rcu(&dev_pasid->link_domain, &svm->devs);
+	list_add_rcu(&dev_pasid->link_domain, &dmar_domain->dev_pasids);
 
 	return 0;
 
-free_dev_pasid:
+out_free_dev_pasid:
 	kfree(dev_pasid);
-free_svm:
-	if (list_empty(&svm->devs)) {
-		mmu_notifier_unregister(&svm->notifier, mm);
-		pasid_private_remove(pasid);
-		kfree(svm);
-	}
+out_unregister:
+	if (list_empty(&dmar_domain->dev_pasids))
+		mmu_notifier_unregister(&domain->notifier, mm);
 
 	return ret;
 }
 
 void intel_svm_remove_dev_pasid(struct device *dev, u32 pasid)
 {
+	struct iommu_domain *domain;
 	struct dev_pasid_info *dev_pasid;
-	struct intel_iommu *iommu;
-	struct intel_svm *svm;
-
-	iommu = device_to_iommu(dev, NULL, NULL);
-	if (!iommu)
-		return;
 
-	if (pasid_to_dev_pasid_info(dev, pasid, &svm, &dev_pasid))
+	domain = iommu_get_domain_for_dev_pasid(dev, pasid,
+						IOMMU_DOMAIN_SVA);
+	if (WARN_ON_ONCE(IS_ERR_OR_NULL(domain)))
 		return;
 
+	dev_pasid = domain_lookup_dev_pasid_info_by_dev(to_dmar_domain(domain), dev);
 	if (dev_pasid) {
 		list_del_rcu(&dev_pasid->link_domain);
 		kfree_rcu(dev_pasid, rcu);
 
-		if (list_empty(&svm->devs)) {
-			if (svm->notifier.ops)
-				mmu_notifier_unregister(&svm->notifier, svm->mm);
-			pasid_private_remove(svm->pasid);
-			kfree(svm);
+		if (list_empty(&to_dmar_domain(domain)->dev_pasids)) {
+			if (domain->notifier.ops)
+				mmu_notifier_unregister(&domain->notifier, domain->mm);
 		}
 	}
 }
@@ -803,6 +734,7 @@  struct iommu_domain *intel_svm_domain_alloc(void)
 	if (!domain)
 		return NULL;
 	domain->domain.ops = &intel_svm_domain_ops;
+	INIT_LIST_HEAD(&domain->dev_pasids);
 
 	return &domain->domain;
 }