[SCSI] zfcp: provide support for NPIV

N_Port ID Virtualization (NPIV) allows a single FCP port to appear as
multiple, distinct ports providing separate port identification. NPIV
is supported by FC HBAs on System z9. zfcp was adapted to support this
new feature.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 87 insertions, 8 deletions

diff --git a/drivers/s390/scsi/zfcp_erp.c b/drivers/s390/scsi/zfcp_erp.c
index 376cb0f6cb74..c4a6799aed44 100644
--- a/drivers/s390/scsi/zfcp_erp.c
+++ b/drivers/s390/scsi/zfcp_erp.c
@@ -82,6 +82,7 @@ static int zfcp_erp_adapter_strategy_open(struct zfcp_erp_action *);
 static int zfcp_erp_adapter_strategy_open_qdio(struct zfcp_erp_action *);
 static int zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *);
 static int zfcp_erp_adapter_strategy_open_fsf_xconfig(struct zfcp_erp_action *);
+static int zfcp_erp_adapter_strategy_open_fsf_xport(struct zfcp_erp_action *);
 static int zfcp_erp_adapter_strategy_open_fsf_statusread(
         struct zfcp_erp_action *);
 
@@ -2258,16 +2259,21 @@ zfcp_erp_adapter_strategy_close_qdio(struct zfcp_erp_action *erp_action)
 static int
 zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *erp_action)
 {
-        int retval;
+        int xconfig, xport;
+
+        if (atomic_test_mask(ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED,
+                             &erp_action->adapter->status)) {
+                zfcp_erp_adapter_strategy_open_fsf_xport(erp_action);
+                atomic_set(&erp_action->adapter->erp_counter, 0);
+                return ZFCP_ERP_FAILED;
+        }
 
-        /* do 'exchange configuration data' */
-        retval = zfcp_erp_adapter_strategy_open_fsf_xconfig(erp_action);
-        if (retval == ZFCP_ERP_FAILED)
-                return retval;
+        xconfig = zfcp_erp_adapter_strategy_open_fsf_xconfig(erp_action);
+        xport   = zfcp_erp_adapter_strategy_open_fsf_xport(erp_action);
+        if ((xconfig == ZFCP_ERP_FAILED) || (xport == ZFCP_ERP_FAILED))
+                return ZFCP_ERP_FAILED;
 
-        /* start the desired number of Status Reads */
-        retval = zfcp_erp_adapter_strategy_open_fsf_statusread(erp_action);
-        return retval;
+        return zfcp_erp_adapter_strategy_open_fsf_statusread(erp_action);
 }
 
 /*
@@ -2350,6 +2356,76 @@ zfcp_erp_adapter_strategy_open_fsf_xconfig(struct zfcp_erp_action *erp_action)
         return retval;
 }
 
+static int
+zfcp_erp_adapter_strategy_open_fsf_xport(struct zfcp_erp_action *erp_action)
+{
+        int retval = ZFCP_ERP_SUCCEEDED;
+        int retries;
+        int sleep;
+        struct zfcp_adapter *adapter = erp_action->adapter;
+
+        atomic_clear_mask(ZFCP_STATUS_ADAPTER_XPORT_OK, &adapter->status);
+
+        for (retries = 0; ; retries++) {
+                ZFCP_LOG_DEBUG("Doing exchange port data\n");
+                zfcp_erp_action_to_running(erp_action);
+                zfcp_erp_timeout_init(erp_action);
+                if (zfcp_fsf_exchange_port_data(erp_action, adapter, NULL)) {
+                        retval = ZFCP_ERP_FAILED;
+                        debug_text_event(adapter->erp_dbf, 5, "a_fstx_xf");
+                        ZFCP_LOG_INFO("error: initiation of exchange of "
+                                      "port data failed for adapter %s\n",
+                                      zfcp_get_busid_by_adapter(adapter));
+                        break;
+                }
+                debug_text_event(adapter->erp_dbf, 6, "a_fstx_xok");
+                ZFCP_LOG_DEBUG("Xchange underway\n");
+
+                /*
+                 * Why this works:
+                 * Both the normal completion handler as well as the timeout
+                 * handler will do an 'up' when the 'exchange port data'
+                 * request completes or times out. Thus, the signal to go on
+                 * won't be lost utilizing this semaphore.
+                 * Furthermore, this 'adapter_reopen' action is
+                 * guaranteed to be the only action being there (highest action
+                 * which prevents other actions from being created).
+                 * Resulting from that, the wake signal recognized here
+                 * _must_ be the one belonging to the 'exchange port
+                 * data' request.
+                 */
+                down(&adapter->erp_ready_sem);
+                if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT) {
+                        ZFCP_LOG_INFO("error: exchange of port data "
+                                      "for adapter %s timed out\n",
+                                      zfcp_get_busid_by_adapter(adapter));
+                        break;
+                }
+
+                if (!atomic_test_mask(ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED,
+                                      &adapter->status))
+                        break;
+
+                ZFCP_LOG_DEBUG("host connection still initialising... "
+                               "waiting and retrying...\n");
+                /* sleep a little bit before retry */
+                sleep = retries < ZFCP_EXCHANGE_PORT_DATA_SHORT_RETRIES ?
+                                ZFCP_EXCHANGE_PORT_DATA_SHORT_SLEEP :
+                                ZFCP_EXCHANGE_PORT_DATA_LONG_SLEEP;
+                msleep(jiffies_to_msecs(sleep));
+        }
+
+        if (atomic_test_mask(ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED,
+                             &adapter->status)) {
+                ZFCP_LOG_INFO("error: exchange of port data for "
+                              "adapter %s failed\n",
+                              zfcp_get_busid_by_adapter(adapter));
+                retval = ZFCP_ERP_FAILED;
+        }
+
+        return retval;
+}
+
 /*
  * function:    
  *
@@ -3599,6 +3675,9 @@ zfcp_erp_adapter_access_changed(struct zfcp_adapter *adapter)
         struct zfcp_port *port;
         unsigned long flags;
 
+        if (adapter->connection_features & FSF_FEATURE_NPIV_MODE)
+                return;
+
         debug_text_event(adapter->erp_dbf, 3, "a_access_recover");
         debug_event(adapter->erp_dbf, 3, &adapter->name, 8);