[SCSI] zfcp: Introduce new kmem_cache for FC request and response data

A data buffer that is passed to the hardware must not cross a page
boundary. zfcp uses a series of kmem_caches to align the data to not
cross a page boundary. Introduce a new kmem_cache for the FC requests
sent from the zfcp driver and use it for the ELS ADISC data.  The goal
is to migrate to the FC kmem_cache in later patches and remove the
request specific kmem_caches.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index 6e32528..fa1834f 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -80,6 +80,7 @@
 extern void zfcp_erp_timeout_handler(unsigned long);
 
 /* zfcp_fc.c */
+extern struct kmem_cache *zfcp_fc_req_cache;
 extern void zfcp_fc_enqueue_event(struct zfcp_adapter *,
 				enum fc_host_event_code event_code, u32);
 extern void zfcp_fc_post_event(struct work_struct *);