[S390] cio: Introduce struct chp_id.

Introduce data type for channel-path IDs.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/drivers/s390/cio/chpid.h b/drivers/s390/cio/chpid.h
new file mode 100644
index 0000000..44cc00e
--- /dev/null
+++ b/drivers/s390/cio/chpid.h
@@ -0,0 +1,51 @@
+/*
+ *  drivers/s390/cio/chpid.h
+ *
+ *    Copyright IBM Corp. 2007
+ *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
+ */
+
+#ifndef S390_CHP_ID_H
+#define S390_CHP_ID_H S390_CHP_ID_H
+
+#include <linux/string.h>
+#include <asm/types.h>
+#include "css.h"
+
+struct chp_id {
+	u8 reserved1;
+	u8 cssid;
+	u8 reserved2;
+	u8 id;
+} __attribute__((packed));
+
+static inline void chp_id_init(struct chp_id *chpid)
+{
+	memset(chpid, 0, sizeof(struct chp_id));
+}
+
+static inline int chp_id_is_equal(struct chp_id *a, struct chp_id *b)
+{
+	return (a->id == b->id) && (a->cssid == b->cssid);
+}
+
+static inline void chp_id_next(struct chp_id *chpid)
+{
+	if (chpid->id < __MAX_CHPID)
+		chpid->id++;
+	else {
+		chpid->id = 0;
+		chpid->cssid++;
+	}
+}
+
+static inline int chp_id_is_valid(struct chp_id *chpid)
+{
+	return (chpid->cssid <= __MAX_CSSID);
+}
+
+
+#define chp_id_for_each(c) \
+	for (chp_id_init(c); chp_id_is_valid(c); chp_id_next(c))
+
+#endif /* S390_CHP_ID_H */