[SCSI] zfcp: Trigger logging in the FCP channel on qdio error conditions

Exploit the cio siosl function to trigger logging in the FCP channel
on qdio error conditions. Add a helper function in zfcp_qdio to ensure
that tracing is only triggered once before calling qdio_shutdown.

Trigger in zfcp for hardware logs are:
 - timeout for FSF requests to the FCP channel
 - "no recommendation" status from FCP channel
 - invalid FSF protocol status
 - stalled outbound queue
 - unknown request id on inbound queue
 - QDIO_ERROR_SLSB_STATE

All of the above triggers run from the Linux qdio softirq context, so
no additional synchronization is necessary for the handling of the
ZFCP_STATUS_ADAPTER_SIOSL_ISSUED flag.

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>

4 files changed, 40 insertions, 4 deletions

diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 6c6374ba1807..e1c6b6e05a75 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -73,6 +73,7 @@ struct zfcp_reqlist;
 
 /* adapter status */
 #define ZFCP_STATUS_ADAPTER_QDIOUP              0x00000002
+#define ZFCP_STATUS_ADAPTER_SIOSL_ISSUED        0x00000004
 #define ZFCP_STATUS_ADAPTER_XCONFIG_OK          0x00000008
 #define ZFCP_STATUS_ADAPTER_HOST_CON_INIT       0x00000010
 #define ZFCP_STATUS_ADAPTER_ERP_PENDING         0x00000100
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index de0925f25dcc..3b93239c6f69 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -152,6 +152,7 @@ extern int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *, struct zfcp_qdio_req *,
                                    struct scatterlist *);
 extern int zfcp_qdio_open(struct zfcp_qdio *);
 extern void zfcp_qdio_close(struct zfcp_qdio *);
+extern void zfcp_qdio_siosl(struct zfcp_adapter *);
 
 /* zfcp_scsi.c */
 extern struct zfcp_data zfcp_data;
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index f9be5d60d92a..9d1d7d1842ce 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -21,6 +21,7 @@
 static void zfcp_fsf_request_timeout_handler(unsigned long data)
 {
         struct zfcp_adapter *adapter = (struct zfcp_adapter *) data;
+        zfcp_qdio_siosl(adapter);
         zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
                                 "fsrth_1", NULL);
 }
@@ -326,6 +327,7 @@ static void zfcp_fsf_fsfstatus_qual_eval(struct zfcp_fsf_req *req)
                 dev_err(&req->adapter->ccw_device->dev,
                         "The FCP adapter reported a problem "
                         "that cannot be recovered\n");
+                zfcp_qdio_siosl(req->adapter);
                 zfcp_erp_adapter_shutdown(req->adapter, 0, "fsfsqe1", req);
                 break;
         }
@@ -416,6 +418,7 @@ static void zfcp_fsf_protstatus_eval(struct zfcp_fsf_req *req)
                 dev_err(&adapter->ccw_device->dev,
                         "0x%x is not a valid transfer protocol status\n",
                         qtcb->prefix.prot_status);
+                zfcp_qdio_siosl(adapter);
                 zfcp_erp_adapter_shutdown(adapter, 0, "fspse_9", req);
         }
         req->status |= ZFCP_STATUS_FSFREQ_ERROR;
@@ -2485,13 +2488,15 @@ void zfcp_fsf_reqid_check(struct zfcp_qdio *qdio, int sbal_idx)
                 req_id = (unsigned long) sbale->addr;
                 fsf_req = zfcp_reqlist_find_rm(adapter->req_list, req_id);
 
-                if (!fsf_req)
+                if (!fsf_req) {
                         /*
                          * Unknown request means that we have potentially memory
                          * corruption and must stop the machine immediately.
                          */
+                        zfcp_qdio_siosl(adapter);
                         panic("error: unknown req_id (%lx) on adapter %s.\n",
                               req_id, dev_name(&adapter->ccw_device->dev));
+                }
 
                 fsf_req->qdio_req.sbal_response = sbal_idx;
                 zfcp_fsf_req_complete(fsf_req);
diff --git a/drivers/s390/scsi/zfcp_qdio.c b/drivers/s390/scsi/zfcp_qdio.c
index aceced8ec7e4..b2635759721c 100644
--- a/drivers/s390/scsi/zfcp_qdio.c
+++ b/drivers/s390/scsi/zfcp_qdio.c
@@ -30,12 +30,15 @@ static int zfcp_qdio_buffers_enqueue(struct qdio_buffer **sbal)
         return 0;
 }
 
-static void zfcp_qdio_handler_error(struct zfcp_qdio *qdio, char *id)
+static void zfcp_qdio_handler_error(struct zfcp_qdio *qdio, char *id,
+                                    unsigned int qdio_err)
 {
         struct zfcp_adapter *adapter = qdio->adapter;
 
         dev_warn(&adapter->ccw_device->dev, "A QDIO problem occurred\n");
 
+        if (qdio_err & QDIO_ERROR_SLSB_STATE)
+                zfcp_qdio_siosl(adapter);
         zfcp_erp_adapter_reopen(adapter,
                                 ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
                                 ZFCP_STATUS_COMMON_ERP_FAILED, id, NULL);
@@ -74,7 +77,7 @@ static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err,
 
         if (unlikely(qdio_err)) {
                 zfcp_dbf_hba_qdio(qdio->adapter->dbf, qdio_err, idx, count);
-                zfcp_qdio_handler_error(qdio, "qdireq1");
+                zfcp_qdio_handler_error(qdio, "qdireq1", qdio_err);
                 return;
         }
 
@@ -95,7 +98,7 @@ static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
 
         if (unlikely(qdio_err)) {
                 zfcp_dbf_hba_qdio(qdio->adapter->dbf, qdio_err, idx, count);
-                zfcp_qdio_handler_error(qdio, "qdires1");
+                zfcp_qdio_handler_error(qdio, "qdires1", qdio_err);
                 return;
         }
 
@@ -361,6 +364,9 @@ int zfcp_qdio_open(struct zfcp_qdio *qdio)
         if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
                 return -EIO;
 
+        atomic_clear_mask(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
+                          &qdio->adapter->status);
+
         zfcp_qdio_setup_init_data(&init_data, qdio);
 
         if (qdio_establish(&init_data))
@@ -440,3 +446,26 @@ int zfcp_qdio_setup(struct zfcp_adapter *adapter)
         return 0;
 }
 
+/**
+ * zfcp_qdio_siosl - Trigger logging in FCP channel
+ * @adapter: The zfcp_adapter where to trigger logging
+ *
+ * Call the cio siosl function to trigger hardware logging.  This
+ * wrapper function sets a flag to ensure hardware logging is only
+ * triggered once before going through qdio shutdown.
+ *
+ * The triggers are always run from qdio tasklet context, so no
+ * additional synchronization is necessary.
+ */
+void zfcp_qdio_siosl(struct zfcp_adapter *adapter)
+{
+        int rc;
+
+        if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_SIOSL_ISSUED)
+                return;
+
+        rc = ccw_device_siosl(adapter->ccw_device);
+        if (!rc)
+                atomic_set_mask(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
+                                &adapter->status);
+}