scsi: cxlflash: Introduce OCXL backend

Add initial infrastructure to support a new cxlflash transport, OCXL.

Claim a dependency on OCXL and add a new file, ocxl_hw.c, which will host the
backend routines that are specific to OCXL.
Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/cxlflash/Kconfig

@@ -4,7 +4,7 @@
 
 config CXLFLASH
 	tristate "Support for IBM CAPI Flash"
-	depends on PCI && SCSI && CXL && EEH
+	depends on PCI && SCSI && CXL && OCXL && EEH
 	select IRQ_POLL
 	default m
 	help

drivers/scsi/cxlflash/Makefile

 obj-$(CONFIG_CXLFLASH) += cxlflash.o
-cxlflash-y += main.o superpipe.o lunmgt.o vlun.o cxl_hw.o
+cxlflash-y += main.o superpipe.o lunmgt.o vlun.o cxl_hw.o ocxl_hw.o

drivers/scsi/cxlflash/backend.h

@@ -13,6 +13,7 @@
  */
 
 extern const struct cxlflash_backend_ops cxlflash_cxl_ops;
+extern const struct cxlflash_backend_ops cxlflash_ocxl_ops;
 
 struct cxlflash_backend_ops {
 	struct module *module;

drivers/scsi/cxlflash/ocxl_hw.c

+/*
+ * CXL Flash Device Driver
+ *
+ * Written by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
+ *             Uma Krishnan <ukrishn@linux.vnet.ibm.com>, IBM Corporation
+ *
+ * Copyright (C) 2018 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <misc/ocxl.h>
+
+#include "backend.h"
+
+/* Backend ops to ocxlflash services */
+const struct cxlflash_backend_ops cxlflash_ocxl_ops = {
+	.module			= THIS_MODULE,
+};