[SCSI] zfcp: Move sbale handling to zfcp_qdio files

Move the code accessing the qdio sbales and zfcp_qdio_req struct to
the zfcp_qdio files and provide helper functions for accessing the
qdio related parts.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

7 files changed, 191 insertions, 151 deletions

diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 72132c13f45b..0b2ae60a6f9f 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -44,23 +44,6 @@ struct zfcp_reqlist;
 /********************* SCSI SPECIFIC DEFINES *********************************/
 #define ZFCP_SCSI_ER_TIMEOUT                    (10*HZ)
 
-/********************* CIO/QDIO SPECIFIC DEFINES *****************************/
-
-/* DMQ bug workaround: don't use last SBALE */
-#define ZFCP_MAX_SBALES_PER_SBAL        (QDIO_MAX_ELEMENTS_PER_BUFFER - 1)
-
-/* index of last SBALE (with respect to DMQ bug workaround) */
-#define ZFCP_LAST_SBALE_PER_SBAL        (ZFCP_MAX_SBALES_PER_SBAL - 1)
-
-/* max. number of (data buffer) SBALEs in largest SBAL chain */
-#define ZFCP_MAX_SBALES_PER_REQ         \
-        (FSF_MAX_SBALS_PER_REQ * ZFCP_MAX_SBALES_PER_SBAL - 2)
-        /* request ID + QTCB in SBALE 0 + 1 of first SBAL in chain */
-
-#define ZFCP_MAX_SECTORS (ZFCP_MAX_SBALES_PER_REQ * 8)
-        /* max. number of (data buffer) SBALEs in largest SBAL chain
-           multiplied with number of sectors per 4k block */
-
 /********************* FSF SPECIFIC DEFINES *********************************/
 
 /* ATTENTION: value must not be used by hardware */
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index 8786a79c7f8f..172da12a2d02 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -3,7 +3,7 @@
  *
  * External function declarations.
  *
- * Copyright IBM Corporation 2002, 2009
+ * Copyright IBM Corporation 2002, 2010
  */
 
 #ifndef ZFCP_EXT_H
@@ -144,8 +144,7 @@ extern void zfcp_fsf_reqid_check(struct zfcp_qdio *, int);
 extern int zfcp_qdio_setup(struct zfcp_adapter *);
 extern void zfcp_qdio_destroy(struct zfcp_qdio *);
 extern int zfcp_qdio_send(struct zfcp_qdio *, struct zfcp_qdio_req *);
-extern int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *,
-                                   struct zfcp_qdio_req *, unsigned long,
+extern int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *, struct zfcp_qdio_req *,
                                    struct scatterlist *, int);
 extern int zfcp_qdio_open(struct zfcp_qdio *);
 extern void zfcp_qdio_close(struct zfcp_qdio *);
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 18564891ea61..ec1b49a75532 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -705,10 +705,9 @@ static struct fsf_qtcb *zfcp_qtcb_alloc(mempool_t *pool)
 }
 
 static struct zfcp_fsf_req *zfcp_fsf_req_create(struct zfcp_qdio *qdio,
-                                                u32 fsf_cmd, mempool_t *pool)
+                                                u32 fsf_cmd, u32 sbtype,
+                                                mempool_t *pool)
 {
-        struct qdio_buffer_element *sbale;
-        struct zfcp_qdio_queue *req_q = &qdio->req_q;
         struct zfcp_adapter *adapter = qdio->adapter;
         struct zfcp_fsf_req *req = zfcp_fsf_alloc(pool);
 
@@ -725,14 +724,6 @@ static struct zfcp_fsf_req *zfcp_fsf_req_create(struct zfcp_qdio *qdio,
         req->adapter = adapter;
         req->fsf_command = fsf_cmd;
         req->req_id = adapter->req_no;
-        req->qdio_req.sbal_number = 1;
-        req->qdio_req.sbal_first = req_q->first;
-        req->qdio_req.sbal_last = req_q->first;
-        req->qdio_req.sbale_curr = 1;
-
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].addr = (void *) req->req_id;
-        sbale[0].flags |= SBAL_FLAGS0_COMMAND;
 
         if (likely(fsf_cmd != FSF_QTCB_UNSOLICITED_STATUS)) {
                 if (likely(pool))
@@ -753,10 +744,11 @@ static struct zfcp_fsf_req *zfcp_fsf_req_create(struct zfcp_qdio *qdio,
                 req->qtcb->prefix.qtcb_version = FSF_QTCB_CURRENT_VERSION;
                 req->qtcb->header.req_handle = req->req_id;
                 req->qtcb->header.fsf_command = req->fsf_command;
-                sbale[1].addr = (void *) req->qtcb;
-                sbale[1].length = sizeof(struct fsf_qtcb);
         }
 
+        zfcp_qdio_req_init(adapter->qdio, &req->qdio_req, req->req_id, sbtype,
+                           req->qtcb, sizeof(struct fsf_qtcb));
+
         if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)) {
                 zfcp_fsf_req_free(req);
                 return ERR_PTR(-EIO);
@@ -803,24 +795,19 @@ int zfcp_fsf_status_read(struct zfcp_qdio *qdio)
         struct zfcp_adapter *adapter = qdio->adapter;
         struct zfcp_fsf_req *req;
         struct fsf_status_read_buffer *sr_buf;
-        struct qdio_buffer_element *sbale;
         int retval = -EIO;
 
         spin_lock_bh(&qdio->req_q_lock);
         if (zfcp_fsf_req_sbal_get(qdio))
                 goto out;
 
-        req = zfcp_fsf_req_create(qdio, FSF_QTCB_UNSOLICITED_STATUS,
+        req = zfcp_fsf_req_create(qdio, FSF_QTCB_UNSOLICITED_STATUS, 0,
                                   adapter->pool.status_read_req);
         if (IS_ERR(req)) {
                 retval = PTR_ERR(req);
                 goto out;
         }
 
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[2].flags |= SBAL_FLAGS_LAST_ENTRY;
-        req->qdio_req.sbale_curr = 2;
-
         sr_buf = mempool_alloc(adapter->pool.status_read_data, GFP_ATOMIC);
         if (!sr_buf) {
                 retval = -ENOMEM;
@@ -828,9 +815,9 @@ int zfcp_fsf_status_read(struct zfcp_qdio *qdio)
         }
         memset(sr_buf, 0, sizeof(*sr_buf));
         req->data = sr_buf;
-        sbale = zfcp_qdio_sbale_curr(qdio, &req->qdio_req);
-        sbale->addr = (void *) sr_buf;
-        sbale->length = sizeof(*sr_buf);
+
+        zfcp_qdio_fill_next(qdio, &req->qdio_req, sr_buf, sizeof(*sr_buf));
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         retval = zfcp_fsf_req_send(req);
         if (retval)
@@ -907,7 +894,6 @@ static void zfcp_fsf_abort_fcp_command_handler(struct zfcp_fsf_req *req)
 struct zfcp_fsf_req *zfcp_fsf_abort_fcp_command(unsigned long old_req_id,
                                                 struct zfcp_unit *unit)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_fsf_req *req = NULL;
         struct zfcp_qdio *qdio = unit->port->adapter->qdio;
 
@@ -915,6 +901,7 @@ struct zfcp_fsf_req *zfcp_fsf_abort_fcp_command(unsigned long old_req_id,
         if (zfcp_fsf_req_sbal_get(qdio))
                 goto out;
         req = zfcp_fsf_req_create(qdio, FSF_QTCB_ABORT_FCP_CMND,
+                                  SBAL_FLAGS0_TYPE_READ,
                                   qdio->adapter->pool.scsi_abort);
         if (IS_ERR(req)) {
                 req = NULL;
@@ -925,9 +912,7 @@ struct zfcp_fsf_req *zfcp_fsf_abort_fcp_command(unsigned long old_req_id,
                        ZFCP_STATUS_COMMON_UNBLOCKED)))
                 goto out_error_free;
 
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         req->data = unit;
         req->handler = zfcp_fsf_abort_fcp_command_handler;
@@ -996,21 +981,14 @@ skip_fsfstatus:
                 ct->handler(ct->handler_data);
 }
 
-static void zfcp_fsf_setup_ct_els_unchained(struct qdio_buffer_element *sbale,
+static void zfcp_fsf_setup_ct_els_unchained(struct zfcp_qdio *qdio,
+                                            struct zfcp_qdio_req *q_req,
                                             struct scatterlist *sg_req,
                                             struct scatterlist *sg_resp)
 {
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_WRITE_READ;
-        sbale[2].addr   = sg_virt(sg_req);
-        sbale[2].length = sg_req->length;
-        sbale[3].addr   = sg_virt(sg_resp);
-        sbale[3].length = sg_resp->length;
-        sbale[3].flags |= SBAL_FLAGS_LAST_ENTRY;
-}
-
-static int zfcp_fsf_one_sbal(struct scatterlist *sg)
-{
-        return sg_is_last(sg) && sg->length <= PAGE_SIZE;
+        zfcp_qdio_fill_next(qdio, q_req, sg_virt(sg_req), sg_req->length);
+        zfcp_qdio_fill_next(qdio, q_req, sg_virt(sg_resp), sg_resp->length);
+        zfcp_qdio_set_sbale_last(qdio, q_req);
 }
 
 static int zfcp_fsf_setup_ct_els_sbals(struct zfcp_fsf_req *req,
@@ -1019,35 +997,34 @@ static int zfcp_fsf_setup_ct_els_sbals(struct zfcp_fsf_req *req,
                                        int max_sbals)
 {
         struct zfcp_adapter *adapter = req->adapter;
-        struct qdio_buffer_element *sbale = zfcp_qdio_sbale_req(adapter->qdio,
-                                                               &req->qdio_req);
         u32 feat = adapter->adapter_features;
         int bytes;
 
         if (!(feat & FSF_FEATURE_ELS_CT_CHAINED_SBALS)) {
-                if (!zfcp_fsf_one_sbal(sg_req) || !zfcp_fsf_one_sbal(sg_resp))
+                if (!zfcp_qdio_sg_one_sbale(sg_req) ||
+                    !zfcp_qdio_sg_one_sbale(sg_resp))
                         return -EOPNOTSUPP;
 
-                zfcp_fsf_setup_ct_els_unchained(sbale, sg_req, sg_resp);
+                zfcp_fsf_setup_ct_els_unchained(adapter->qdio, &req->qdio_req,
+                                                sg_req, sg_resp);
                 return 0;
         }
 
         /* use single, unchained SBAL if it can hold the request */
-        if (zfcp_fsf_one_sbal(sg_req) && zfcp_fsf_one_sbal(sg_resp)) {
-                zfcp_fsf_setup_ct_els_unchained(sbale, sg_req, sg_resp);
+        if (zfcp_qdio_sg_one_sbale(sg_req) || zfcp_qdio_sg_one_sbale(sg_resp)) {
+                zfcp_fsf_setup_ct_els_unchained(adapter->qdio, &req->qdio_req,
+                                                sg_req, sg_resp);
                 return 0;
         }
 
         bytes = zfcp_qdio_sbals_from_sg(adapter->qdio, &req->qdio_req,
-                                        SBAL_FLAGS0_TYPE_WRITE_READ,
                                         sg_req, max_sbals);
         if (bytes <= 0)
                 return -EIO;
         req->qtcb->bottom.support.req_buf_length = bytes;
-        req->qdio_req.sbale_curr = ZFCP_LAST_SBALE_PER_SBAL;
+        zfcp_qdio_skip_to_last_sbale(&req->qdio_req);
 
         bytes = zfcp_qdio_sbals_from_sg(adapter->qdio, &req->qdio_req,
-                                        SBAL_FLAGS0_TYPE_WRITE_READ,
                                         sg_resp, max_sbals);
         req->qtcb->bottom.support.resp_buf_length = bytes;
         if (bytes <= 0)
@@ -1094,7 +1071,8 @@ int zfcp_fsf_send_ct(struct zfcp_fc_wka_port *wka_port,
         if (zfcp_fsf_req_sbal_get(qdio))
                 goto out;
 
-        req = zfcp_fsf_req_create(qdio, FSF_QTCB_SEND_GENERIC, pool);
+        req = zfcp_fsf_req_create(qdio, FSF_QTCB_SEND_GENERIC,
+                                  SBAL_FLAGS0_TYPE_WRITE_READ, pool);
 
         if (IS_ERR(req)) {
                 ret = PTR_ERR(req);
@@ -1103,7 +1081,7 @@ int zfcp_fsf_send_ct(struct zfcp_fc_wka_port *wka_port,
 
         req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
         ret = zfcp_fsf_setup_ct_els(req, ct->req, ct->resp,
-                                    FSF_MAX_SBALS_PER_REQ, timeout);
+                                    ZFCP_FSF_MAX_SBALS_PER_REQ, timeout);
         if (ret)
                 goto failed_send;
 
@@ -1190,7 +1168,8 @@ int zfcp_fsf_send_els(struct zfcp_adapter *adapter, u32 d_id,
         if (zfcp_fsf_req_sbal_get(qdio))
                 goto out;
 
-        req = zfcp_fsf_req_create(qdio, FSF_QTCB_SEND_ELS, NULL);
+        req = zfcp_fsf_req_create(qdio, FSF_QTCB_SEND_ELS,
+                                  SBAL_FLAGS0_TYPE_WRITE_READ, NULL);
 
         if (IS_ERR(req)) {
                 ret = PTR_ERR(req);
@@ -1224,7 +1203,6 @@ out:
 
 int zfcp_fsf_exchange_config_data(struct zfcp_erp_action *erp_action)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_fsf_req *req;
         struct zfcp_qdio *qdio = erp_action->adapter->qdio;
         int retval = -EIO;
@@ -1234,6 +1212,7 @@ int zfcp_fsf_exchange_config_data(struct zfcp_erp_action *erp_action)
                 goto out;
 
         req = zfcp_fsf_req_create(qdio, FSF_QTCB_EXCHANGE_CONFIG_DATA,
+                                  SBAL_FLAGS0_TYPE_READ,
                                   qdio->adapter->pool.erp_req);
 
         if (IS_ERR(req)) {
@@ -1242,9 +1221,7 @@ int zfcp_fsf_exchange_config_data(struct zfcp_erp_action *erp_action)
         }
 
         req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         req->qtcb->bottom.config.feature_selection =
                         FSF_FEATURE_CFDC |
@@ -1269,7 +1246,6 @@ out:
 int zfcp_fsf_exchange_config_data_sync(struct zfcp_qdio *qdio,
                                        struct fsf_qtcb_bottom_config *data)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_fsf_req *req = NULL;
         int retval = -EIO;
 
@@ -1277,16 +1253,15 @@ int zfcp_fsf_exchange_config_data_sync(struct zfcp_qdio *qdio,
         if (zfcp_fsf_req_sbal_get(qdio))
                 goto out_unlock;
 
-        req = zfcp_fsf_req_create(qdio, FSF_QTCB_EXCHANGE_CONFIG_DATA, NULL);
+        req = zfcp_fsf_req_create(qdio, FSF_QTCB_EXCHANGE_CONFIG_DATA,
+                                  SBAL_FLAGS0_TYPE_READ, NULL);
 
         if (IS_ERR(req)) {
                 retval = PTR_ERR(req);
                 goto out_unlock;
         }
 
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
         req->handler = zfcp_fsf_exchange_config_data_handler;
 
         req->qtcb->bottom.config.feature_selection =
@@ -1320,7 +1295,6 @@ out_unlock:
 int zfcp_fsf_exchange_port_data(struct zfcp_erp_action *erp_action)
 {
         struct zfcp_qdio *qdio = erp_action->adapter->qdio;
-        struct qdio_buffer_element *sbale;
         struct zfcp_fsf_req *req;
         int retval = -EIO;
 
@@ -1332,6 +1306,7 @@ int zfcp_fsf_exchange_port_data(struct zfcp_erp_action *erp_action)
                 goto out;
 
         req = zfcp_fsf_req_create(qdio, FSF_QTCB_EXCHANGE_PORT_DATA,
+                                  SBAL_FLAGS0_TYPE_READ,
                                   qdio->adapter->pool.erp_req);
 
         if (IS_ERR(req)) {
@@ -1340,9 +1315,7 @@ int zfcp_fsf_exchange_port_data(struct zfcp_erp_action *erp_action)
         }
 
         req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         req->handler = zfcp_fsf_exchange_port_data_handler;
         req->erp_action = erp_action;
@@ -1368,7 +1341,6 @@ out:
 int zfcp_fsf_exchange_port_data_sync(struct zfcp_qdio *qdio,
                                      struct fsf_qtcb_bottom_port *data)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_fsf_req *req = NULL;
         int retval = -EIO;
 
@@ -1379,7 +1351,8 @@ int zfcp_fsf_exchange_port_data_sync(struct zfcp_qdio *qdio,
         if (zfcp_fsf_req_sbal_get(qdio))
                 goto out_unlock;
 
-        req = zfcp_fsf_req_create(qdio, FSF_QTCB_EXCHANGE_PORT_DATA, NULL);
+        req = zfcp_fsf_req_create(qdio, FSF_QTCB_EXCHANGE_PORT_DATA,
+                                  SBAL_FLAGS0_TYPE_READ, NULL);
 
         if (IS_ERR(req)) {
                 retval = PTR_ERR(req);
@@ -1389,9 +1362,7 @@ int zfcp_fsf_exchange_port_data_sync(struct zfcp_qdio *qdio,
         if (data)
                 req->data = data;
 
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         req->handler = zfcp_fsf_exchange_port_data_handler;
         zfcp_fsf_start_timer(req, ZFCP_FSF_REQUEST_TIMEOUT);
@@ -1485,7 +1456,6 @@ out:
  */
 int zfcp_fsf_open_port(struct zfcp_erp_action *erp_action)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_qdio *qdio = erp_action->adapter->qdio;
         struct zfcp_port *port = erp_action->port;
         struct zfcp_fsf_req *req;
@@ -1496,6 +1466,7 @@ int zfcp_fsf_open_port(struct zfcp_erp_action *erp_action)
                 goto out;
 
         req = zfcp_fsf_req_create(qdio, FSF_QTCB_OPEN_PORT_WITH_DID,
+                                  SBAL_FLAGS0_TYPE_READ,
                                   qdio->adapter->pool.erp_req);
 
         if (IS_ERR(req)) {
@@ -1504,9 +1475,7 @@ int zfcp_fsf_open_port(struct zfcp_erp_action *erp_action)
         }
 
         req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         req->handler = zfcp_fsf_open_port_handler;
         hton24(req->qtcb->bottom.support.d_id, port->d_id);
@@ -1556,7 +1525,6 @@ static void zfcp_fsf_close_port_handler(struct zfcp_fsf_req *req)
  */
 int zfcp_fsf_close_port(struct zfcp_erp_action *erp_action)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_qdio *qdio = erp_action->adapter->qdio;
         struct zfcp_fsf_req *req;
         int retval = -EIO;
@@ -1566,6 +1534,7 @@ int zfcp_fsf_close_port(struct zfcp_erp_action *erp_action)
                 goto out;
 
         req = zfcp_fsf_req_create(qdio, FSF_QTCB_CLOSE_PORT,
+                                  SBAL_FLAGS0_TYPE_READ,
                                   qdio->adapter->pool.erp_req);
 
         if (IS_ERR(req)) {
@@ -1574,9 +1543,7 @@ int zfcp_fsf_close_port(struct zfcp_erp_action *erp_action)
         }
 
         req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         req->handler = zfcp_fsf_close_port_handler;
         req->data = erp_action->port;
@@ -1633,7 +1600,6 @@ out:
  */
 int zfcp_fsf_open_wka_port(struct zfcp_fc_wka_port *wka_port)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_qdio *qdio = wka_port->adapter->qdio;
         struct zfcp_fsf_req *req;
         int retval = -EIO;
@@ -1643,6 +1609,7 @@ int zfcp_fsf_open_wka_port(struct zfcp_fc_wka_port *wka_port)
                 goto out;
 
         req = zfcp_fsf_req_create(qdio, FSF_QTCB_OPEN_PORT_WITH_DID,
+                                  SBAL_FLAGS0_TYPE_READ,
                                   qdio->adapter->pool.erp_req);
 
         if (unlikely(IS_ERR(req))) {
@@ -1651,9 +1618,7 @@ int zfcp_fsf_open_wka_port(struct zfcp_fc_wka_port *wka_port)
         }
 
         req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         req->handler = zfcp_fsf_open_wka_port_handler;
         hton24(req->qtcb->bottom.support.d_id, wka_port->d_id);
@@ -1688,7 +1653,6 @@ static void zfcp_fsf_close_wka_port_handler(struct zfcp_fsf_req *req)
  */
 int zfcp_fsf_close_wka_port(struct zfcp_fc_wka_port *wka_port)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_qdio *qdio = wka_port->adapter->qdio;
         struct zfcp_fsf_req *req;
         int retval = -EIO;
@@ -1698,6 +1662,7 @@ int zfcp_fsf_close_wka_port(struct zfcp_fc_wka_port *wka_port)
                 goto out;
 
         req = zfcp_fsf_req_create(qdio, FSF_QTCB_CLOSE_PORT,
+                                  SBAL_FLAGS0_TYPE_READ,
                                   qdio->adapter->pool.erp_req);
 
         if (unlikely(IS_ERR(req))) {
@@ -1706,9 +1671,7 @@ int zfcp_fsf_close_wka_port(struct zfcp_fc_wka_port *wka_port)
         }
 
         req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         req->handler = zfcp_fsf_close_wka_port_handler;
         req->data = wka_port;
@@ -1782,7 +1745,6 @@ static void zfcp_fsf_close_physical_port_handler(struct zfcp_fsf_req *req)
  */
 int zfcp_fsf_close_physical_port(struct zfcp_erp_action *erp_action)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_qdio *qdio = erp_action->adapter->qdio;
         struct zfcp_fsf_req *req;
         int retval = -EIO;
@@ -1792,6 +1754,7 @@ int zfcp_fsf_close_physical_port(struct zfcp_erp_action *erp_action)
                 goto out;
 
         req = zfcp_fsf_req_create(qdio, FSF_QTCB_CLOSE_PHYSICAL_PORT,
+                                  SBAL_FLAGS0_TYPE_READ,
                                   qdio->adapter->pool.erp_req);
 
         if (IS_ERR(req)) {
@@ -1800,9 +1763,7 @@ int zfcp_fsf_close_physical_port(struct zfcp_erp_action *erp_action)
         }
 
         req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         req->data = erp_action->port;
         req->qtcb->header.port_handle = erp_action->port->handle;
@@ -1954,7 +1915,6 @@ static void zfcp_fsf_open_unit_handler(struct zfcp_fsf_req *req)
  */
 int zfcp_fsf_open_unit(struct zfcp_erp_action *erp_action)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_adapter *adapter = erp_action->adapter;
         struct zfcp_qdio *qdio = adapter->qdio;
         struct zfcp_fsf_req *req;
@@ -1965,6 +1925,7 @@ int zfcp_fsf_open_unit(struct zfcp_erp_action *erp_action)
                 goto out;
 
         req = zfcp_fsf_req_create(qdio, FSF_QTCB_OPEN_LUN,
+                                  SBAL_FLAGS0_TYPE_READ,
                                   adapter->pool.erp_req);
 
         if (IS_ERR(req)) {
@@ -1973,9 +1934,7 @@ int zfcp_fsf_open_unit(struct zfcp_erp_action *erp_action)
         }
 
         req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         req->qtcb->header.port_handle = erp_action->port->handle;
         req->qtcb->bottom.support.fcp_lun = erp_action->unit->fcp_lun;
@@ -2041,7 +2000,6 @@ static void zfcp_fsf_close_unit_handler(struct zfcp_fsf_req *req)
  */
 int zfcp_fsf_close_unit(struct zfcp_erp_action *erp_action)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_qdio *qdio = erp_action->adapter->qdio;
         struct zfcp_fsf_req *req;
         int retval = -EIO;
@@ -2051,6 +2009,7 @@ int zfcp_fsf_close_unit(struct zfcp_erp_action *erp_action)
                 goto out;
 
         req = zfcp_fsf_req_create(qdio, FSF_QTCB_CLOSE_LUN,
+                                  SBAL_FLAGS0_TYPE_READ,
                                   qdio->adapter->pool.erp_req);
 
         if (IS_ERR(req)) {
@@ -2059,9 +2018,7 @@ int zfcp_fsf_close_unit(struct zfcp_erp_action *erp_action)
         }
 
         req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         req->qtcb->header.port_handle = erp_action->port->handle;
         req->qtcb->header.lun_handle = erp_action->unit->handle;
@@ -2289,8 +2246,11 @@ int zfcp_fsf_send_fcp_command_task(struct zfcp_unit *unit,
                 goto out;
         }
 
+        if (scsi_cmnd->sc_data_direction == DMA_TO_DEVICE)
+                sbtype = SBAL_FLAGS0_TYPE_WRITE;
+
         req = zfcp_fsf_req_create(qdio, FSF_QTCB_FCP_CMND,
-                                  adapter->pool.scsi_req);
+                                  sbtype, adapter->pool.scsi_req);
 
         if (IS_ERR(req)) {
                 retval = PTR_ERR(req);
@@ -2298,7 +2258,6 @@ int zfcp_fsf_send_fcp_command_task(struct zfcp_unit *unit,
         }
 
         req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
-        get_device(&unit->dev);
         req->unit = unit;
         req->data = scsi_cmnd;
         req->handler = zfcp_fsf_send_fcp_command_handler;
@@ -2323,20 +2282,21 @@ int zfcp_fsf_send_fcp_command_task(struct zfcp_unit *unit,
                 break;
         case DMA_TO_DEVICE:
                 req->qtcb->bottom.io.data_direction = FSF_DATADIR_WRITE;
-                sbtype = SBAL_FLAGS0_TYPE_WRITE;
                 break;
         case DMA_BIDIRECTIONAL:
                 goto failed_scsi_cmnd;
         }
 
+        get_device(&unit->dev);
+
         fcp_cmnd = (struct fcp_cmnd *) &req->qtcb->bottom.io.fcp_cmnd;
         zfcp_fc_scsi_to_fcp(fcp_cmnd, scsi_cmnd);
 
-        real_bytes = zfcp_qdio_sbals_from_sg(qdio, &req->qdio_req, sbtype,
+        real_bytes = zfcp_qdio_sbals_from_sg(qdio, &req->qdio_req,
                                              scsi_sglist(scsi_cmnd),
-                                             FSF_MAX_SBALS_PER_REQ);
+                                             ZFCP_FSF_MAX_SBALS_PER_REQ);
         if (unlikely(real_bytes < 0)) {
-                if (req->qdio_req.sbal_number >= FSF_MAX_SBALS_PER_REQ) {
+                if (req->qdio_req.sbal_number >= ZFCP_FSF_MAX_SBALS_PER_REQ) {
                         dev_err(&adapter->ccw_device->dev,
                                 "Oversize data package, unit 0x%016Lx "
                                 "on port 0x%016Lx closed\n",
@@ -2371,7 +2331,6 @@ out:
  */
 struct zfcp_fsf_req *zfcp_fsf_send_fcp_ctm(struct zfcp_unit *unit, u8 tm_flags)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_fsf_req *req = NULL;
         struct fcp_cmnd *fcp_cmnd;
         struct zfcp_qdio *qdio = unit->port->adapter->qdio;
@@ -2385,6 +2344,7 @@ struct zfcp_fsf_req *zfcp_fsf_send_fcp_ctm(struct zfcp_unit *unit, u8 tm_flags)
                 goto out;
 
         req = zfcp_fsf_req_create(qdio, FSF_QTCB_FCP_CMND,
+                                  SBAL_FLAGS0_TYPE_WRITE,
                                   qdio->adapter->pool.scsi_req);
 
         if (IS_ERR(req)) {
@@ -2401,9 +2361,7 @@ struct zfcp_fsf_req *zfcp_fsf_send_fcp_ctm(struct zfcp_unit *unit, u8 tm_flags)
         req->qtcb->bottom.io.service_class = FSF_CLASS_3;
         req->qtcb->bottom.io.fcp_cmnd_length = FCP_CMND_LEN;
 
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= SBAL_FLAGS0_TYPE_WRITE;
-        sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
+        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
         fcp_cmnd = (struct fcp_cmnd *) &req->qtcb->bottom.io.fcp_cmnd;
         zfcp_fc_fcp_tm(fcp_cmnd, unit->device, tm_flags);
@@ -2432,7 +2390,6 @@ static void zfcp_fsf_control_file_handler(struct zfcp_fsf_req *req)
 struct zfcp_fsf_req *zfcp_fsf_control_file(struct zfcp_adapter *adapter,
                                            struct zfcp_fsf_cfdc *fsf_cfdc)
 {
-        struct qdio_buffer_element *sbale;
         struct zfcp_qdio *qdio = adapter->qdio;
         struct zfcp_fsf_req *req = NULL;
         struct fsf_qtcb_bottom_support *bottom;
@@ -2456,7 +2413,7 @@ struct zfcp_fsf_req *zfcp_fsf_control_file(struct zfcp_adapter *adapter,
         if (zfcp_fsf_req_sbal_get(qdio))
                 goto out;
 
-        req = zfcp_fsf_req_create(qdio, fsf_cfdc->command, NULL);
+        req = zfcp_fsf_req_create(qdio, fsf_cfdc->command, direction, NULL);
         if (IS_ERR(req)) {
                 retval = -EPERM;
                 goto out;
@@ -2464,16 +2421,13 @@ struct zfcp_fsf_req *zfcp_fsf_control_file(struct zfcp_adapter *adapter,
 
         req->handler = zfcp_fsf_control_file_handler;
 
-        sbale = zfcp_qdio_sbale_req(qdio, &req->qdio_req);
-        sbale[0].flags |= direction;
-
         bottom = &req->qtcb->bottom.support;
         bottom->operation_subtype = FSF_CFDC_OPERATION_SUBTYPE;
         bottom->option = fsf_cfdc->option;
 
         bytes = zfcp_qdio_sbals_from_sg(qdio, &req->qdio_req,
-                                        direction, fsf_cfdc->sg,
-                                        FSF_MAX_SBALS_PER_REQ);
+                                        fsf_cfdc->sg,
+                                        ZFCP_FSF_MAX_SBALS_PER_REQ);
         if (bytes != ZFCP_CFDC_MAX_SIZE) {
                 zfcp_fsf_req_free(req);
                 goto out;
diff --git a/drivers/s390/scsi/zfcp_fsf.h b/drivers/s390/scsi/zfcp_fsf.h
index b3de682b64cf..4008bd786793 100644
--- a/drivers/s390/scsi/zfcp_fsf.h
+++ b/drivers/s390/scsi/zfcp_fsf.h
@@ -3,7 +3,7 @@
  *
  * Interface to the FSF support functions.
  *
- * Copyright IBM Corporation 2002, 2009
+ * Copyright IBM Corporation 2002, 2010
  */
 
 #ifndef FSF_H
@@ -152,7 +152,12 @@
 #define FSF_CLASS_3                             0x00000003
 
 /* SBAL chaining */
-#define FSF_MAX_SBALS_PER_REQ                   36
+#define ZFCP_FSF_MAX_SBALS_PER_REQ              36
+
+/* max. number of (data buffer) SBALEs in largest SBAL chain
+ * request ID + QTCB in SBALE 0 + 1 of first SBAL in chain   */
+#define ZFCP_FSF_MAX_SBALES_PER_REQ     \
+        (ZFCP_FSF_MAX_SBALS_PER_REQ * ZFCP_QDIO_MAX_SBALES_PER_SBAL - 2)
 
 /* logging space behind QTCB */
 #define FSF_QTCB_LOG_SIZE                       1024
diff --git a/drivers/s390/scsi/zfcp_qdio.c b/drivers/s390/scsi/zfcp_qdio.c
index aa68515abe21..98d54a9cd563 100644
--- a/drivers/s390/scsi/zfcp_qdio.c
+++ b/drivers/s390/scsi/zfcp_qdio.c
@@ -3,7 +3,7 @@
  *
  * Setup and helper functions to access QDIO.
  *
- * Copyright IBM Corporation 2002, 2009
+ * Copyright IBM Corporation 2002, 2010
  */
 
 #define KMSG_COMPONENT "zfcp"
@@ -151,8 +151,7 @@ static void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
 }
 
 static struct qdio_buffer_element *
-zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
-                     unsigned long sbtype)
+zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 {
         struct qdio_buffer_element *sbale;
 
@@ -180,17 +179,16 @@ zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
 
         /* set storage-block type for new SBAL */
         sbale = zfcp_qdio_sbale_curr(qdio, q_req);
-        sbale->flags |= sbtype;
+        sbale->flags |= q_req->sbtype;
 
         return sbale;
 }
 
 static struct qdio_buffer_element *
-zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
-                     unsigned int sbtype)
+zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 {
-        if (q_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
-                return zfcp_qdio_sbal_chain(qdio, q_req, sbtype);
+        if (q_req->sbale_curr == ZFCP_QDIO_LAST_SBALE_PER_SBAL)
+                return zfcp_qdio_sbal_chain(qdio, q_req);
         q_req->sbale_curr++;
         return zfcp_qdio_sbale_curr(qdio, q_req);
 }
@@ -208,15 +206,14 @@ static void zfcp_qdio_undo_sbals(struct zfcp_qdio *qdio,
 
 /**
  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
- * @fsf_req: request to be processed
- * @sbtype: SBALE flags
+ * @qdio: pointer to struct zfcp_qdio
+ * @q_req: pointer to struct zfcp_qdio_req
  * @sg: scatter-gather list
  * @max_sbals: upper bound for number of SBALs to be used
  * Returns: number of bytes, or error (negativ)
  */
 int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
-                            unsigned long sbtype, struct scatterlist *sg,
-                            int max_sbals)
+                            struct scatterlist *sg, int max_sbals)
 {
         struct qdio_buffer_element *sbale;
         int bytes = 0;
@@ -226,10 +223,10 @@ int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
 
         /* set storage-block type for this request */
         sbale = zfcp_qdio_sbale_req(qdio, q_req);
-        sbale->flags |= sbtype;
+        sbale->flags |= q_req->sbtype;
 
         for (; sg; sg = sg_next(sg)) {
-                sbale = zfcp_qdio_sbale_next(qdio, q_req, sbtype);
+                sbale = zfcp_qdio_sbale_next(qdio, q_req);
                 if (!sbale) {
                         atomic_inc(&qdio->req_q_full);
                         zfcp_qdio_undo_sbals(qdio, q_req);
diff --git a/drivers/s390/scsi/zfcp_qdio.h b/drivers/s390/scsi/zfcp_qdio.h
index f2b5a363bb84..138fba577b48 100644
--- a/drivers/s390/scsi/zfcp_qdio.h
+++ b/drivers/s390/scsi/zfcp_qdio.h
@@ -13,6 +13,12 @@
 
 #define ZFCP_QDIO_SBALE_LEN     PAGE_SIZE
 
+/* DMQ bug workaround: don't use last SBALE */
+#define ZFCP_QDIO_MAX_SBALES_PER_SBAL   (QDIO_MAX_ELEMENTS_PER_BUFFER - 1)
+
+/* index of last SBALE (with respect to DMQ bug workaround) */
+#define ZFCP_QDIO_LAST_SBALE_PER_SBAL   (ZFCP_QDIO_MAX_SBALES_PER_SBAL - 1)
+
 /**
  * struct zfcp_qdio_queue - qdio queue buffer, zfcp index and free count
  * @sbal: qdio buffers
@@ -51,6 +57,7 @@ struct zfcp_qdio {
 
 /**
  * struct zfcp_qdio_req - qdio queue related values for a request
+ * @sbtype: sbal type flags for sbale 0
  * @sbal_number: number of free sbals
  * @sbal_first: first sbal for this request
  * @sbal_last: last sbal for this request
@@ -61,6 +68,7 @@ struct zfcp_qdio {
  * @qdio_inb_usage: usage of inbound queue
  */
 struct zfcp_qdio_req {
+        u32     sbtype;
         u8      sbal_number;
         u8      sbal_first;
         u8      sbal_last;
@@ -108,4 +116,98 @@ zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
                                q_req->sbale_curr);
 }
 
+/**
+ * zfcp_qdio_req_init - initialize qdio request
+ * @qdio: request queue where to start putting the request
+ * @q_req: the qdio request to start
+ * @req_id: The request id
+ * @sbtype: type flags to set for all sbals
+ * @data: First data block
+ * @len: Length of first data block
+ *
+ * This is the start of putting the request into the queue, the last
+ * step is passing the request to zfcp_qdio_send. The request queue
+ * lock must be held during the whole process from init to send.
+ */
+static inline
+void zfcp_qdio_req_init(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
+                        unsigned long req_id, u32 sbtype, void *data, u32 len)
+{
+        struct qdio_buffer_element *sbale;
+
+        q_req->sbal_first = q_req->sbal_last = qdio->req_q.first;
+        q_req->sbal_number = 1;
+        q_req->sbtype = sbtype;
+
+        sbale = zfcp_qdio_sbale_req(qdio, q_req);
+        sbale->addr = (void *) req_id;
+        sbale->flags |= SBAL_FLAGS0_COMMAND;
+        sbale->flags |= sbtype;
+
+        q_req->sbale_curr = 1;
+        sbale++;
+        sbale->addr = data;
+        if (likely(data))
+                sbale->length = len;
+}
+
+/**
+ * zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests
+ * @qdio: pointer to struct zfcp_qdio
+ * @q_req: pointer to struct zfcp_queue_req
+ *
+ * This is only required for single sbal requests, calling it when
+ * wrapping around to the next sbal is a bug.
+ */
+static inline
+void zfcp_qdio_fill_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
+                         void *data, u32 len)
+{
+        struct qdio_buffer_element *sbale;
+
+        BUG_ON(q_req->sbale_curr == ZFCP_QDIO_LAST_SBALE_PER_SBAL);
+        q_req->sbale_curr++;
+        sbale = zfcp_qdio_sbale_curr(qdio, q_req);
+        sbale->addr = data;
+        sbale->length = len;
+}
+
+/**
+ * zfcp_qdio_set_sbale_last - set last entry flag in current sbale
+ * @qdio: pointer to struct zfcp_qdio
+ * @q_req: pointer to struct zfcp_queue_req
+ */
+static inline
+void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio,
+                              struct zfcp_qdio_req *q_req)
+{
+        struct qdio_buffer_element *sbale;
+
+        sbale = zfcp_qdio_sbale_curr(qdio, q_req);
+        sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
+}
+
+/**
+ * zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data
+ * @sg: The scatterlist where to check the data size
+ *
+ * Returns: 1 when one sbale is enough for the data in the scatterlist,
+ *          0 if not.
+ */
+static inline
+int zfcp_qdio_sg_one_sbale(struct scatterlist *sg)
+{
+        return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN;
+}
+
+/**
+ * zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal
+ * @q_req: The current zfcp_qdio_req
+ */
+static inline
+void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio_req *q_req)
+{
+        q_req->sbale_curr = ZFCP_QDIO_LAST_SBALE_PER_SBAL;
+}
+
 #endif /* ZFCP_QDIO_H */
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index 066b0507a639..be5d2c60453d 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -677,11 +677,11 @@ struct zfcp_data zfcp_data = {
                 .eh_host_reset_handler   = zfcp_scsi_eh_host_reset_handler,
                 .can_queue               = 4096,
                 .this_id                 = -1,
-                .sg_tablesize            = ZFCP_MAX_SBALES_PER_REQ,
+                .sg_tablesize            = ZFCP_FSF_MAX_SBALES_PER_REQ,
                 .cmd_per_lun             = 1,
                 .use_clustering          = 1,
                 .sdev_attrs              = zfcp_sysfs_sdev_attrs,
-                .max_sectors             = (ZFCP_MAX_SBALES_PER_REQ * 8),
+                .max_sectors             = (ZFCP_FSF_MAX_SBALES_PER_REQ * 8),
                 .dma_boundary            = ZFCP_QDIO_SBALE_LEN - 1,
                 .shost_attrs             = zfcp_sysfs_shost_attrs,
         },