s390/hmcdrv: HMC drive CD/DVD access

This device driver allows accessing a HMC drive CD/DVD-ROM.
It can be used in a LPAR and z/VM environment.

Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Ralf Hoppe <rhoppe@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/char/hmcdrv_cache.h

@@ -0,0 +1,24 @@
+/*
+ *    SE/HMC Drive (Read) Cache Functions
+ *
+ *    Copyright IBM Corp. 2013
+ *    Author(s): Ralf Hoppe (rhoppe@de.ibm.com)
+ */
+
+#ifndef __HMCDRV_CACHE_H__
+#define __HMCDRV_CACHE_H__
+
+#include <linux/mmzone.h>
+#include "hmcdrv_ftp.h"
+
+#define HMCDRV_CACHE_SIZE_DFLT	(MAX_ORDER_NR_PAGES * PAGE_SIZE / 2UL)
+
+typedef ssize_t (*hmcdrv_cache_ftpfunc)(const struct hmcdrv_ftp_cmdspec *ftp,
+					size_t *fsize);
+
+ssize_t hmcdrv_cache_cmd(const struct hmcdrv_ftp_cmdspec *ftp,
+			 hmcdrv_cache_ftpfunc func);
+int hmcdrv_cache_startup(size_t cachesize);
+void hmcdrv_cache_shutdown(void);
+
+#endif	 /* __HMCDRV_CACHE_H__ */