diff --git a/src/northbridge/amd/agesa/family15tn/iommu.c b/src/northbridge/amd/agesa/family15tn/iommu.c
new file mode 100644
index 0000000..3765f20
--- /dev/null
+++ b/src/northbridge/amd/agesa/family15tn/iommu.c
@@ -0,0 +1,73 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2013 Rudolf Marek <r.marek@assembler.cz>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <device/device.h>
+#include <device/pci.h>
+#include <device/pci_ids.h>
+#include <device/pci_ops.h>
+#include <lib.h>
+
+static void iommu_read_resources(device_t dev)
+{
+	struct resource *res;
+
+	/* Get the normal pci resources of this device */
+	pci_dev_read_resources(dev);
+
+	/* Add an extra subtractive resource for both memory and I/O. */
+	res = new_resource(dev, 0x44);
+	res->size = 512 * 1024;
+	res->align = log2(res->size);
+	res->gran = log2(res->size);
+	res->limit = 0xffffffff;	/* 4G */
+	res->flags = IORESOURCE_MEM;
+}
+
+static void iommu_set_resources(device_t dev)
+{
+	struct resource *res;
+
+	pci_dev_set_resources(dev);
+
+	res = find_resource(dev, 0x44);
+	/* Remember this resource has been stored */
+	res->flags |= IORESOURCE_STORED;
+	/* For now, do only 32-bit space allocation */
+	pci_write_config32(dev, 0x48, 0x0);
+	pci_write_config32(dev, 0x44, res->base | (1 << 0));
+}
+
+static struct pci_operations lops_pci = {
+	.set_subsystem = pci_dev_set_subsystem,
+};
+
+static struct device_operations iommu_ops = {
+	.read_resources = iommu_read_resources,
+	.set_resources = iommu_set_resources,
+	.enable_resources = pci_dev_enable_resources,
+	.init = 0,
+	.scan_bus = 0,
+	.ops_pci = &lops_pci,
+};
+
+static const struct pci_driver iommu_driver __pci_driver = {
+	.ops = &iommu_ops,
+	.vendor = PCI_VENDOR_ID_AMD,
+	.device = PCI_DEVICE_ID_AMD_15H_NB_IOMMU,
+};