[S390] cio: provide helper functions for fcx enabled I/O

Provide functions which can be used to incrementally construct fcx
enabled I/O control blocks.
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>

drivers/s390/cio/Makefile

@@ -2,7 +2,8 @@
 # Makefile for the S/390 common i/o drivers
 #
 
-obj-y += airq.o blacklist.o chsc.o cio.o css.o chp.o idset.o scsw.o fcx.o
+obj-y += airq.o blacklist.o chsc.o cio.o css.o chp.o idset.o scsw.o fcx.o \
+	 itcw.o
 ccw_device-objs += device.o device_fsm.o device_ops.o
 ccw_device-objs += device_id.o device_pgid.o device_status.o
 obj-y += ccw_device.o cmf.o

include/asm-s390/itcw.h

+/*
+ *  Functions for incremental construction of fcx enabled I/O control blocks.
+ *
+ *    Copyright IBM Corp. 2008
+ *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
+ */
+
+#ifndef _ASM_S390_ITCW_H
+#define _ASM_S390_ITCW_H _ASM_S390_ITCW_H
+
+#include <linux/types.h>
+#include <asm/fcx.h>
+
+#define ITCW_OP_READ	0
+#define ITCW_OP_WRITE	1
+
+struct itcw;
+
+struct tcw *itcw_get_tcw(struct itcw *itcw);
+size_t itcw_calc_size(int intrg, int max_tidaws, int intrg_max_tidaws);
+struct itcw *itcw_init(void *buffer, size_t size, int op, int intrg,
+		       int max_tidaws, int intrg_max_tidaws);
+struct dcw *itcw_add_dcw(struct itcw *itcw, u8 cmd, u8 flags, void *cd,
+			 u8 cd_count, u32 count);
+struct tidaw *itcw_add_tidaw(struct itcw *itcw, u8 flags, void *addr,
+			     u32 count);
+void itcw_set_data(struct itcw *itcw, void *addr, int use_tidal);
+void itcw_finalize(struct itcw *itcw);
+
+#endif /* _ASM_S390_ITCW_H */