thunderbolt: Add tb_property_copy_dir()

This function takes a deep copy of the properties. We need this in order
to support more dynamic properties per XDomain connection as required by
the USB4 inter-domain service spec.

Signed-off-by: Mika Westerberg <[e-mail]>

drivers/thunderbolt/property.c

···
 }
 
 /**
+ * tb_property_copy_dir() - Take a deep copy of directory
+ * @dir: Directory to copy
+ *
+ * This function takes a deep copy of @dir and returns back the copy. In
+ * case of error returns %NULL. The resulting directory needs to be
+ * released by calling tb_property_free_dir().
+ */
+struct tb_property_dir *tb_property_copy_dir(const struct tb_property_dir *dir)
+{
+	struct tb_property *property, *p = NULL;
+	struct tb_property_dir *d;
+
+	if (!dir)
+		return NULL;
+
+	d = tb_property_create_dir(dir->uuid);
+	if (!d)
+		return NULL;
+
+	list_for_each_entry(property, &dir->properties, list) {
+		struct tb_property *p;
+
+		p = tb_property_alloc(property->key, property->type);
+		if (!p)
+			goto err_free;
+
+		p->length = property->length;
+
+		switch (property->type) {
+		case TB_PROPERTY_TYPE_DIRECTORY:
+			p->value.dir = tb_property_copy_dir(property->value.dir);
+			if (!p->value.dir)
+				goto err_free;
+			break;
+
+		case TB_PROPERTY_TYPE_DATA:
+			p->value.data = kmemdup(property->value.data,
+						property->length * 4,
+						GFP_KERNEL);
+			if (!p->value.data)
+				goto err_free;
+			break;
+
+		case TB_PROPERTY_TYPE_TEXT:
+			p->value.text = kzalloc(p->length * 4, GFP_KERNEL);
+			if (!p->value.text)
+				goto err_free;
+			strcpy(p->value.text, property->value.text);
+			break;
+
+		case TB_PROPERTY_TYPE_VALUE:
+			p->value.immediate = property->value.immediate;
+			break;
+
+		default:
+			break;
+		}
+
+		list_add_tail(&p->list, &d->properties);
+	}
+
+	return d;
+
+err_free:
+	kfree(p);
+	tb_property_free_dir(d);
+
+	return NULL;
+}
+
+/**
  * tb_property_add_immediate() - Add immediate property to directory
  * @parent: Directory to add the property
  * @key: Key for the property

include/linux/thunderbolt.h

···
 					      size_t block_len);
 ssize_t tb_property_format_dir(const struct tb_property_dir *dir, u32 *block,
 			       size_t block_len);
+struct tb_property_dir *tb_property_copy_dir(const struct tb_property_dir *dir);
 struct tb_property_dir *tb_property_create_dir(const uuid_t *uuid);
 void tb_property_free_dir(struct tb_property_dir *dir);
 int tb_property_add_immediate(struct tb_property_dir *parent, const char *key,