arm-smmu-v3/sva: Add SVA domain support

Add support for SVA domain allocation and provide an SVA-specific
iommu_domain_ops. This implementation is based on the existing SVA
code. Possible cleanup and refactoring are left for incremental
changes later.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Link: https://lore.kernel.org/r/20221031005917.45690-9-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

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

@@ -549,3 +549,64 @@ void arm_smmu_sva_notifier_synchronize(void)
 	 */
 	mmu_notifier_synchronize();
 }
+
+void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain,
+				   struct device *dev, ioasid_t id)
+{
+	struct mm_struct *mm = domain->mm;
+	struct arm_smmu_bond *bond = NULL, *t;
+	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+
+	mutex_lock(&sva_lock);
+	list_for_each_entry(t, &master->bonds, list) {
+		if (t->mm == mm) {
+			bond = t;
+			break;
+		}
+	}
+
+	if (!WARN_ON(!bond) && refcount_dec_and_test(&bond->refs)) {
+		list_del(&bond->list);
+		arm_smmu_mmu_notifier_put(bond->smmu_mn);
+		kfree(bond);
+	}
+	mutex_unlock(&sva_lock);
+}
+
+static int arm_smmu_sva_set_dev_pasid(struct iommu_domain *domain,
+				      struct device *dev, ioasid_t id)
+{
+	int ret = 0;
+	struct iommu_sva *handle;
+	struct mm_struct *mm = domain->mm;
+
+	mutex_lock(&sva_lock);
+	handle = __arm_smmu_sva_bind(dev, mm);
+	if (IS_ERR(handle))
+		ret = PTR_ERR(handle);
+	mutex_unlock(&sva_lock);
+
+	return ret;
+}
+
+static void arm_smmu_sva_domain_free(struct iommu_domain *domain)
+{
+	kfree(domain);
+}
+
+static const struct iommu_domain_ops arm_smmu_sva_domain_ops = {
+	.set_dev_pasid		= arm_smmu_sva_set_dev_pasid,
+	.free			= arm_smmu_sva_domain_free
+};
+
+struct iommu_domain *arm_smmu_sva_domain_alloc(void)
+{
+	struct iommu_domain *domain;
+
+	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+	if (!domain)
+		return NULL;
+	domain->ops = &arm_smmu_sva_domain_ops;
+
+	return domain;
+}

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

@@ -2009,6 +2009,9 @@ static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
 {
 	struct arm_smmu_domain *smmu_domain;
 
+	if (type == IOMMU_DOMAIN_SVA)
+		return arm_smmu_sva_domain_alloc();
+
 	if (type != IOMMU_DOMAIN_UNMANAGED &&
 	    type != IOMMU_DOMAIN_DMA &&
 	    type != IOMMU_DOMAIN_DMA_FQ &&
@@ -2838,6 +2841,17 @@ static int arm_smmu_def_domain_type(struct device *dev)
 	return 0;
 }
 
+static void arm_smmu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
+{
+	struct iommu_domain *domain;
+
+	domain = iommu_get_domain_for_dev_pasid(dev, pasid, IOMMU_DOMAIN_SVA);
+	if (WARN_ON(IS_ERR(domain)) || !domain)
+		return;
+
+	arm_smmu_sva_remove_dev_pasid(domain, dev, pasid);
+}
+
 static struct iommu_ops arm_smmu_ops = {
 	.capable		= arm_smmu_capable,
 	.domain_alloc		= arm_smmu_domain_alloc,
@@ -2846,6 +2860,7 @@ 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,
+	.remove_dev_pasid	= arm_smmu_remove_dev_pasid,
 	.dev_enable_feat	= arm_smmu_dev_enable_feature,
 	.dev_disable_feat	= arm_smmu_dev_disable_feature,
 	.sva_bind		= arm_smmu_sva_bind,

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

@@ -758,6 +758,9 @@ struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm);
 void arm_smmu_sva_unbind(struct iommu_sva *handle);
 u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle);
 void arm_smmu_sva_notifier_synchronize(void);
+struct iommu_domain *arm_smmu_sva_domain_alloc(void);
+void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain,
+				   struct device *dev, ioasid_t id);
 #else /* CONFIG_ARM_SMMU_V3_SVA */
 static inline bool arm_smmu_sva_supported(struct arm_smmu_device *smmu)
 {
@@ -803,5 +806,16 @@ static inline u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle)
 }
 
 static inline void arm_smmu_sva_notifier_synchronize(void) {}
+
+static inline struct iommu_domain *arm_smmu_sva_domain_alloc(void)
+{
+	return NULL;
+}
+
+static inline void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain,
+						 struct device *dev,
+						 ioasid_t id)
+{
+}
 #endif /* CONFIG_ARM_SMMU_V3_SVA */
 #endif /* _ARM_SMMU_V3_H */