iommu/s390: Add iommu api for s390 pci devices

This adds an IOMMU API implementation for s390 PCI devices.

Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 34d9603..c873e68 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -62,6 +62,8 @@
 	u8		size;		/* order 2 exponent */
 };
 
+struct s390_domain;
+
 /* Private data per function */
 struct zpci_dev {
 	struct pci_dev	*pdev;
@@ -118,6 +120,8 @@
 
 	struct dentry	*debugfs_dev;
 	struct dentry	*debugfs_perf;
+
+	struct s390_domain *s390_domain; /* s390 IOMMU domain data */
 };
 
 static inline bool zdev_enabled(struct zpci_dev *zdev)