[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>

1 files changed, 15 insertions, 12 deletions

diff --git a/drivers/s390/scsi/zfcp_fc.h b/drivers/s390/scsi/zfcp_fc.h
index b464ae01086c..4351b4e81b3c 100644
--- a/drivers/s390/scsi/zfcp_fc.h
+++ b/drivers/s390/scsi/zfcp_fc.h
@@ -123,19 +123,22 @@ struct zfcp_fc_gpn_ft {
 };
 
 /**
- * struct zfcp_fc_els_adisc - everything required in zfcp for issuing ELS ADISC
- * @els: data required for issuing els fsf command
- * @req: scatterlist entry for ELS ADISC request
- * @resp: scatterlist entry for ELS ADISC response
- * @adisc_req: ELS ADISC request data
- * @adisc_resp: ELS ADISC response data
+ * struct zfcp_fc_req - Container for FC ELS and CT requests sent from zfcp
+ * @ct_els: data required for issuing fsf command
+ * @sg_req: scatterlist entry for request data
+ * @sg_rsp: scatterlist entry for response data
+ * @u: request specific data
  */
-struct zfcp_fc_els_adisc {
-        struct zfcp_fsf_ct_els els;
-        struct scatterlist req;
-        struct scatterlist resp;
-        struct fc_els_adisc adisc_req;
-        struct fc_els_adisc adisc_resp;
+struct zfcp_fc_req {
+        struct zfcp_fsf_ct_els                          ct_els;
+        struct scatterlist                              sg_req;
+        struct scatterlist                              sg_rsp;
+        union {
+                struct {
+                        struct fc_els_adisc             req;
+                        struct fc_els_adisc             rsp;
+                } adisc;
+        } u;
 };
 
 /**