1 files changed, 137 insertions, 4 deletions

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index a94ec648c88b..bf22992beb98 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -43,6 +43,7 @@ struct iommu_group {
 	struct kobject kobj;
 	struct kobject *devices_kobj;
 	struct list_head devices;
+	struct xarray pasid_array;
 	struct mutex mutex;
 	void *iommu_data;
 	void (*iommu_data_release)(void *iommu_data);
@@ -723,6 +724,7 @@ struct iommu_group *iommu_group_alloc(void)
 	mutex_init(&group->mutex);
 	INIT_LIST_HEAD(&group->devices);
 	INIT_LIST_HEAD(&group->entry);
+	xa_init(&group->pasid_array);
 
 	ret = ida_alloc(&iommu_group_ida, GFP_KERNEL);
 	if (ret < 0) {
@@ -3106,7 +3108,8 @@ int iommu_device_use_default_domain(struct device *dev)
 
 	mutex_lock(&group->mutex);
 	if (group->owner_cnt) {
-		if (group->owner || !iommu_is_default_domain(group)) {
+		if (group->owner || !iommu_is_default_domain(group) ||
+		    !xa_empty(&group->pasid_array)) {
 			ret = -EBUSY;
 			goto unlock_out;
 		}
@@ -3137,7 +3140,7 @@ void iommu_device_unuse_default_domain(struct device *dev)
 		return;
 
 	mutex_lock(&group->mutex);
-	if (!WARN_ON(!group->owner_cnt))
+	if (!WARN_ON(!group->owner_cnt || !xa_empty(&group->pasid_array)))
 		group->owner_cnt--;
 
 	mutex_unlock(&group->mutex);
@@ -3185,7 +3188,8 @@ int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner)
 		ret = -EPERM;
 		goto unlock_out;
 	} else {
-		if (group->domain && group->domain != group->default_domain) {
+		if ((group->domain && group->domain != group->default_domain) ||
+		    !xa_empty(&group->pasid_array)) {
 			ret = -EBUSY;
 			goto unlock_out;
 		}
@@ -3219,7 +3223,8 @@ void iommu_group_release_dma_owner(struct iommu_group *group)
 	int ret;
 
 	mutex_lock(&group->mutex);
-	if (WARN_ON(!group->owner_cnt || !group->owner))
+	if (WARN_ON(!group->owner_cnt || !group->owner ||
+		    !xa_empty(&group->pasid_array)))
 		goto unlock_out;
 
 	group->owner_cnt = 0;
@@ -3250,3 +3255,131 @@ bool iommu_group_dma_owner_claimed(struct iommu_group *group)
 	return user;
 }
 EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed);
+
+static int __iommu_set_group_pasid(struct iommu_domain *domain,
+				   struct iommu_group *group, ioasid_t pasid)
+{
+	struct group_device *device;
+	int ret = 0;
+
+	list_for_each_entry(device, &group->devices, list) {
+		ret = domain->ops->set_dev_pasid(domain, device->dev, pasid);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+static void __iommu_remove_group_pasid(struct iommu_group *group,
+				       ioasid_t pasid)
+{
+	struct group_device *device;
+	const struct iommu_ops *ops;
+
+	list_for_each_entry(device, &group->devices, list) {
+		ops = dev_iommu_ops(device->dev);
+		ops->remove_dev_pasid(device->dev, pasid);
+	}
+}
+
+/*
+ * iommu_attach_device_pasid() - Attach a domain to pasid of device
+ * @domain: the iommu domain.
+ * @dev: the attached device.
+ * @pasid: the pasid of the device.
+ *
+ * Return: 0 on success, or an error.
+ */
+int iommu_attach_device_pasid(struct iommu_domain *domain,
+			      struct device *dev, ioasid_t pasid)
+{
+	struct iommu_group *group;
+	void *curr;
+	int ret;
+
+	if (!domain->ops->set_dev_pasid)
+		return -EOPNOTSUPP;
+
+	group = iommu_group_get(dev);
+	if (!group)
+		return -ENODEV;
+
+	mutex_lock(&group->mutex);
+	curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, GFP_KERNEL);
+	if (curr) {
+		ret = xa_err(curr) ? : -EBUSY;
+		goto out_unlock;
+	}
+
+	ret = __iommu_set_group_pasid(domain, group, pasid);
+	if (ret) {
+		__iommu_remove_group_pasid(group, pasid);
+		xa_erase(&group->pasid_array, pasid);
+	}
+out_unlock:
+	mutex_unlock(&group->mutex);
+	iommu_group_put(group);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_attach_device_pasid);
+
+/*
+ * iommu_detach_device_pasid() - Detach the domain from pasid of device
+ * @domain: the iommu domain.
+ * @dev: the attached device.
+ * @pasid: the pasid of the device.
+ *
+ * The @domain must have been attached to @pasid of the @dev with
+ * iommu_attach_device_pasid().
+ */
+void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev,
+			       ioasid_t pasid)
+{
+	struct iommu_group *group = iommu_group_get(dev);
+
+	mutex_lock(&group->mutex);
+	__iommu_remove_group_pasid(group, pasid);
+	WARN_ON(xa_erase(&group->pasid_array, pasid) != domain);
+	mutex_unlock(&group->mutex);
+
+	iommu_group_put(group);
+}
+EXPORT_SYMBOL_GPL(iommu_detach_device_pasid);
+
+/*
+ * iommu_get_domain_for_dev_pasid() - Retrieve domain for @pasid of @dev
+ * @dev: the queried device
+ * @pasid: the pasid of the device
+ * @type: matched domain type, 0 for any match
+ *
+ * This is a variant of iommu_get_domain_for_dev(). It returns the existing
+ * domain attached to pasid of a device. Callers must hold a lock around this
+ * function, and both iommu_attach/detach_dev_pasid() whenever a domain of
+ * type is being manipulated. This API does not internally resolve races with
+ * attach/detach.
+ *
+ * Return: attached domain on success, NULL otherwise.
+ */
+struct iommu_domain *iommu_get_domain_for_dev_pasid(struct device *dev,
+						    ioasid_t pasid,
+						    unsigned int type)
+{
+	struct iommu_domain *domain;
+	struct iommu_group *group;
+
+	group = iommu_group_get(dev);
+	if (!group)
+		return NULL;
+
+	xa_lock(&group->pasid_array);
+	domain = xa_load(&group->pasid_array, pasid);
+	if (type && domain && domain->type != type)
+		domain = ERR_PTR(-EBUSY);
+	xa_unlock(&group->pasid_array);
+	iommu_group_put(group);
+
+	return domain;
+}
+EXPORT_SYMBOL_GPL(iommu_get_domain_for_dev_pasid);