1 files changed, 57 insertions, 0 deletions
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
new file mode 100644
index 000000000000..43d473989a06
--- /dev/null
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES
+ */
+#include <linux/iommu.h>
+
+#include "iommufd_private.h"
+
+void iommufd_hw_pagetable_destroy(struct iommufd_object *obj)
+{
+	struct iommufd_hw_pagetable *hwpt =
+		container_of(obj, struct iommufd_hw_pagetable, obj);
+
+	WARN_ON(!list_empty(&hwpt->devices));
+
+	iommu_domain_free(hwpt->domain);
+	refcount_dec(&hwpt->ioas->obj.users);
+	mutex_destroy(&hwpt->devices_lock);
+}
+
+/**
+ * iommufd_hw_pagetable_alloc() - Get an iommu_domain for a device
+ * @ictx: iommufd context
+ * @ioas: IOAS to associate the domain with
+ * @dev: Device to get an iommu_domain for
+ *
+ * Allocate a new iommu_domain and return it as a hw_pagetable.
+ */
+struct iommufd_hw_pagetable *
+iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
+			   struct device *dev)
+{
+	struct iommufd_hw_pagetable *hwpt;
+	int rc;
+
+	hwpt = iommufd_object_alloc(ictx, hwpt, IOMMUFD_OBJ_HW_PAGETABLE);
+	if (IS_ERR(hwpt))
+		return hwpt;
+
+	hwpt->domain = iommu_domain_alloc(dev->bus);
+	if (!hwpt->domain) {
+		rc = -ENOMEM;
+		goto out_abort;
+	}
+
+	INIT_LIST_HEAD(&hwpt->devices);
+	INIT_LIST_HEAD(&hwpt->hwpt_item);
+	mutex_init(&hwpt->devices_lock);
+	/* Pairs with iommufd_hw_pagetable_destroy() */
+	refcount_inc(&ioas->obj.users);
+	hwpt->ioas = ioas;
+	return hwpt;
+
+out_abort:
+	iommufd_object_abort(ictx, &hwpt->obj);
+	return ERR_PTR(rc);
+}