4 files changed, 82 insertions, 1 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 8c7e2b778ef1..d23027a2f2f0 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -847,6 +847,14 @@ zfcp_unit_enqueue(struct zfcp_port *port, fcp_lun_t fcp_lun)
         /* mark unit unusable as long as sysfs registration is not complete */
         atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
 
+        spin_lock_init(&unit->latencies.lock);
+        unit->latencies.write.channel.min = 0xFFFFFFFF;
+        unit->latencies.write.fabric.min = 0xFFFFFFFF;
+        unit->latencies.read.channel.min = 0xFFFFFFFF;
+        unit->latencies.read.fabric.min = 0xFFFFFFFF;
+        unit->latencies.cmd.channel.min = 0xFFFFFFFF;
+        unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
+
         if (device_register(&unit->sysfs_device)) {
                 kfree(unit);
                 return NULL;
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index bda8c77b22da..306fcd0cae31 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -708,6 +708,24 @@ struct zfcp_erp_action {
         struct timer_list timer;
 };
 
+struct fsf_latency_record {
+        u32 min;
+        u32 max;
+        u64 sum;
+};
+
+struct latency_cont {
+        struct fsf_latency_record channel;
+        struct fsf_latency_record fabric;
+        u64 counter;
+};
+
+struct zfcp_latencies {
+        struct latency_cont read;
+        struct latency_cont write;
+        struct latency_cont cmd;
+        spinlock_t lock;
+};
 
 struct zfcp_adapter {
         struct list_head        list;              /* list of adapters */
@@ -723,6 +741,7 @@ struct zfcp_adapter {
         u32                     adapter_features;  /* FCP channel features */
         u32                     connection_features; /* host connection features */
         u32                     hardware_version;  /* of FCP channel */
+        u16                     timer_ticks;       /* time int for a tick */
         struct Scsi_Host        *scsi_host;        /* Pointer to mid-layer */
         struct list_head        port_list_head;    /* remote port list */
         struct list_head        port_remove_lh;    /* head of ports to be
@@ -822,6 +841,7 @@ struct zfcp_unit {
         struct scsi_device     *device;        /* scsi device struct pointer */
         struct zfcp_erp_action erp_action;     /* pending error recovery */
         atomic_t               erp_counter;
+        struct zfcp_latencies   latencies;
 };
 
 /* FSF request */
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index b2ea4ea051f5..1e7136483c1b 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -2005,6 +2005,7 @@ zfcp_fsf_exchange_config_evaluate(struct zfcp_fsf_req *fsf_req, int xchg_ok)
                 fc_host_supported_classes(shost) =
                                 FC_COS_CLASS2 | FC_COS_CLASS3;
                 adapter->hydra_version = bottom->adapter_type;
+                adapter->timer_ticks = bottom->timer_interval;
                 if (fc_host_permanent_port_name(shost) == -1)
                         fc_host_permanent_port_name(shost) =
                                 fc_host_port_name(shost);
@@ -3649,6 +3650,46 @@ zfcp_fsf_send_fcp_command_task_management(struct zfcp_adapter *adapter,
         return fsf_req;
 }
 
+static void zfcp_fsf_update_lat(struct fsf_latency_record *lat_rec, u32 lat)
+{
+        lat_rec->sum += lat;
+        if (lat_rec->min > lat)
+                lat_rec->min = lat;
+        if (lat_rec->max < lat)
+                lat_rec->max = lat;
+}
+
+static void zfcp_fsf_req_latency(struct zfcp_fsf_req *fsf_req)
+{
+        struct fsf_qual_latency_info *lat_inf;
+        struct latency_cont *lat;
+        struct zfcp_unit *unit;
+        unsigned long flags;
+
+        lat_inf = &fsf_req->qtcb->prefix.prot_status_qual.latency_info;
+        unit = fsf_req->unit;
+
+        switch (fsf_req->qtcb->bottom.io.data_direction) {
+        case FSF_DATADIR_READ:
+                lat = &unit->latencies.read;
+                break;
+        case FSF_DATADIR_WRITE:
+                lat = &unit->latencies.write;
+                break;
+        case FSF_DATADIR_CMND:
+                lat = &unit->latencies.cmd;
+                break;
+        default:
+                return;
+        }
+
+        spin_lock_irqsave(&unit->latencies.lock, flags);
+        zfcp_fsf_update_lat(&lat->channel, lat_inf->channel_lat);
+        zfcp_fsf_update_lat(&lat->fabric, lat_inf->fabric_lat);
+        lat->counter++;
+        spin_unlock_irqrestore(&unit->latencies.lock, flags);
+}
+
 /*
  * function:    zfcp_fsf_send_fcp_command_handler
  *
@@ -3922,6 +3963,9 @@ zfcp_fsf_send_fcp_command_task_handler(struct zfcp_fsf_req *fsf_req)
                               fcp_rsp_iu->fcp_sns_len);
         }
 
+        if (fsf_req->adapter->adapter_features & FSF_FEATURE_MEASUREMENT_DATA)
+                zfcp_fsf_req_latency(fsf_req);
+
         /* check FCP_RSP_INFO */
         if (unlikely(fcp_rsp_iu->validity.bits.fcp_rsp_len_valid)) {
                 ZFCP_LOG_DEBUG("rsp_len is valid\n");
diff --git a/drivers/s390/scsi/zfcp_fsf.h b/drivers/s390/scsi/zfcp_fsf.h
index 099970b27001..8b1a7d9c840f 100644
--- a/drivers/s390/scsi/zfcp_fsf.h
+++ b/drivers/s390/scsi/zfcp_fsf.h
@@ -323,11 +323,18 @@ struct fsf_link_down_info {
         u8 vendor_specific_code;
 } __attribute__ ((packed));
 
+struct fsf_qual_latency_info {
+        u32 channel_lat;
+        u32 fabric_lat;
+        u8 res1[8];
+} __attribute__ ((packed));
+
 union fsf_prot_status_qual {
         u64 doubleword[FSF_PROT_STATUS_QUAL_SIZE / sizeof(u64)];
         struct fsf_qual_version_error   version_error;
         struct fsf_qual_sequence_error  sequence_error;
         struct fsf_link_down_info link_down_info;
+        struct fsf_qual_latency_info latency_info;
 } __attribute__ ((packed));
 
 struct fsf_qtcb_prefix {
@@ -437,7 +444,9 @@ struct fsf_qtcb_bottom_config {
         u32 fc_link_speed;
         u32 adapter_type;
         u32 peer_d_id;
-        u8 res2[12];
+        u8 res1[2];
+        u16 timer_interval;
+        u8 res2[8];
         u32 s_id;
         struct fsf_nport_serv_param nport_serv_param;
         u8 reserved_nport_serv_param[16];