iommu/amd: Add driver stub for AMD IOMMUv2 support

Add a Kconfig option for the optional driver. Since it is
optional it can be compiled as a module and will only be
loaded when required by another driver.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

drivers/iommu/Kconfig

@@ -60,6 +60,14 @@ config AMD_IOMMU_STATS
 	  information to userspace via debugfs.
 	  If unsure, say N.
 
+config AMD_IOMMU_V2
+	tristate "AMD IOMMU Version 2 driver (EXPERIMENTAL)"
+	depends on AMD_IOMMU && EXPERIMENTAL
+	---help---
+	  This option enables support for the AMD IOMMUv2 features of the IOMMU
+	  hardware. Select this option if you want to use devices that support
+	  the the PCI PRI and PASID interface.
+
 # Intel IOMMU support
 config DMAR_TABLE
 	bool

drivers/iommu/Makefile

@@ -1,6 +1,7 @@
 obj-$(CONFIG_IOMMU_API) += iommu.o
 obj-$(CONFIG_MSM_IOMMU) += msm_iommu.o msm_iommu_dev.o
 obj-$(CONFIG_AMD_IOMMU) += amd_iommu.o amd_iommu_init.o
+obj-$(CONFIG_AMD_IOMMU_V2) += amd_iommu_v2.o
 obj-$(CONFIG_DMAR_TABLE) += dmar.o
 obj-$(CONFIG_INTEL_IOMMU) += iova.o intel-iommu.o
 obj-$(CONFIG_IRQ_REMAP) += intr_remapping.o

drivers/iommu/amd_iommu_v2.c

@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2010-2012 Advanced Micro Devices, Inc.
+ * Author: Joerg Roedel <joerg.roedel@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include <linux/module.h>
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Joerg Roedel <joerg.roedel@amd.com>");
+
+static int __init amd_iommu_v2_init(void)
+{
+	pr_info("AMD IOMMUv2 driver by Joerg Roedel <joerg.roedel@amd.com>");
+
+	return 0;
+}
+
+static void __exit amd_iommu_v2_exit(void)
+{
+}
+
+module_init(amd_iommu_v2_init);
+module_exit(amd_iommu_v2_exit);