scsi: read host_busy via scsi_host_busy()

No functional change.

Just introduce scsi_host_busy() and replace the direct read of
scsi_host->host_busy with this new API.

Cc: Omar Sandoval <osandov@fb.com>,
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
Cc: James Bottomley <james.bottomley@hansenpartnership.com>,
Cc: Christoph Hellwig <hch@lst.de>,
Cc: Don Brace <don.brace@microsemi.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

10 files changed, 26 insertions, 15 deletions

diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c
index c9a52905070e..713f69033f20 100644
--- a/drivers/scsi/advansys.c
+++ b/drivers/scsi/advansys.c
@@ -2416,8 +2416,8 @@ static void asc_prt_scsi_host(struct Scsi_Host *s)
         struct asc_board *boardp = shost_priv(s);
 
         printk("Scsi_Host at addr 0x%p, device %s\n", s, dev_name(boardp->dev));
-        printk(" host_busy %u, host_no %d,\n",
-               atomic_read(&s->host_busy), s->host_no);
+        printk(" host_busy %d, host_no %d,\n",
+               scsi_host_busy(s), s->host_no);
 
         printk(" base 0x%lx, io_port 0x%lx, irq %d,\n",
                (ulong)s->base, (ulong)s->io_port, boardp->irq);
@@ -3182,8 +3182,8 @@ static void asc_prt_driver_conf(struct seq_file *m, struct Scsi_Host *shost)
                 shost->host_no);
 
         seq_printf(m,
-                   " host_busy %u, max_id %u, max_lun %llu, max_channel %u\n",
-                   atomic_read(&shost->host_busy), shost->max_id,
+                   " host_busy %d, max_id %u, max_lun %llu, max_channel %u\n",
+                   scsi_host_busy(shost), shost->max_id,
                    shost->max_lun, shost->max_channel);
 
         seq_printf(m,
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 3771e59a9fae..ea4b0bb0c1cd 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -564,6 +564,16 @@ struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
 EXPORT_SYMBOL(scsi_host_get);
 
 /**
+ * scsi_host_busy - Return the host busy counter
+ * @shost:      Pointer to Scsi_Host to inc.
+ **/
+int scsi_host_busy(struct Scsi_Host *shost)
+{
+        return atomic_read(&shost->host_busy);
+}
+EXPORT_SYMBOL(scsi_host_busy);
+
+/**
  * scsi_host_put - dec a Scsi_Host ref count
  * @shost:      Pointer to Scsi_Host to dec.
  **/
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index ceab5e5c41c2..33229348dcb6 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -759,7 +759,7 @@ retry:
         spin_unlock_irq(shost->host_lock);
 
         SAS_DPRINTK("Enter %s busy: %d failed: %d\n",
-                    __func__, atomic_read(&shost->host_busy), shost->host_failed);
+                    __func__, scsi_host_busy(shost), shost->host_failed);
         /*
          * Deal with commands that still have SAS tasks (i.e. they didn't
          * complete via the normal sas_task completion mechanism),
@@ -801,7 +801,7 @@ out:
                 goto retry;
 
         SAS_DPRINTK("--- Exit %s: busy: %d failed: %d tries: %d\n",
-                    __func__, atomic_read(&shost->host_busy),
+                    __func__, scsi_host_busy(shost),
                     shost->host_failed, tries);
 }
 
diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index e6ba02793610..9aa9590c5373 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -2834,7 +2834,7 @@ static int megasas_reset_bus_host(struct scsi_cmnd *scmd)
                 "SCSI command pointer: (%p)\t SCSI host state: %d\t"
                 " SCSI host busy: %d\t FW outstanding: %d\n",
                 scmd, scmd->device->host->shost_state,
-                atomic_read((atomic_t *)&scmd->device->host->host_busy),
+                scsi_host_busy(scmd->device->host),
                 atomic_read(&instance->fw_outstanding));
 
         /*
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 2053970fc9f8..dc41bd3de08a 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -3250,7 +3250,7 @@ _base_recovery_check(struct MPT3SAS_ADAPTER *ioc)
          * See _wait_for_commands_to_complete() call with regards to this code.
          */
         if (ioc->shost_recovery && ioc->pending_io_count) {
-                ioc->pending_io_count = atomic_read(&ioc->shost->host_busy);
+                ioc->pending_io_count = scsi_host_busy(ioc->shost);
                 if (ioc->pending_io_count == 0)
                         wake_up(&ioc->reset_wq);
         }
@@ -6857,7 +6857,7 @@ mpt3sas_wait_for_commands_to_complete(struct MPT3SAS_ADAPTER *ioc)
                 return;
 
         /* pending command count */
-        ioc->pending_io_count = atomic_read(&ioc->shost->host_busy);
+        ioc->pending_io_count = scsi_host_busy(ioc->shost);
 
         if (!ioc->pending_io_count)
                 return;
diff --git a/drivers/scsi/qlogicpti.c b/drivers/scsi/qlogicpti.c
index 8578e566ab41..9d09228eee28 100644
--- a/drivers/scsi/qlogicpti.c
+++ b/drivers/scsi/qlogicpti.c
@@ -959,7 +959,7 @@ static inline void update_can_queue(struct Scsi_Host *host, u_int in_ptr, u_int
         /* Temporary workaround until bug is found and fixed (one bug has been found
            already, but fixing it makes things even worse) -jj */
         int num_free = QLOGICPTI_REQ_QUEUE_LEN - REQ_QUEUE_DEPTH(in_ptr, out_ptr) - 64;
-        host->can_queue = atomic_read(&host->host_busy) + num_free;
+        host->can_queue = scsi_host_busy(host) + num_free;
         host->sg_tablesize = QLOGICPTI_MAX_SG(num_free);
 }
 
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 70ef3c39061d..fc1356d101b0 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -167,7 +167,7 @@ void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
                         if (level > 3)
                                 scmd_printk(KERN_INFO, cmd,
                                             "scsi host busy %d failed %d\n",
-                                            atomic_read(&cmd->device->host->host_busy),
+                                            scsi_host_busy(cmd->device->host),
                                             cmd->device->host->host_failed);
                 }
         }
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 8932ae81a15a..6a014fd15fe9 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -66,7 +66,7 @@ void scsi_eh_wakeup(struct Scsi_Host *shost)
 {
         lockdep_assert_held(shost->host_lock);
 
-        if (atomic_read(&shost->host_busy) == shost->host_failed) {
+        if (scsi_host_busy(shost) == shost->host_failed) {
                 trace_scsi_eh_wakeup(shost);
                 wake_up_process(shost->ehandler);
                 SCSI_LOG_ERROR_RECOVERY(5, shost_printk(KERN_INFO, shost,
@@ -2155,7 +2155,7 @@ int scsi_error_handler(void *data)
                         break;
 
                 if ((shost->host_failed == 0 && shost->host_eh_scheduled == 0) ||
-                    shost->host_failed != atomic_read(&shost->host_busy)) {
+                    shost->host_failed != scsi_host_busy(shost)) {
                         SCSI_LOG_ERROR_RECOVERY(1,
                                 shost_printk(KERN_INFO, shost,
                                              "scsi_eh_%d: sleeping\n",
@@ -2170,7 +2170,7 @@ int scsi_error_handler(void *data)
                                      "scsi_eh_%d: waking up %d/%d/%d\n",
                                      shost->host_no, shost->host_eh_scheduled,
                                      shost->host_failed,
-                                     atomic_read(&shost->host_busy)));
+                                     scsi_host_busy(shost)));
 
                 /*
                  * We have a host that is failing for some reason.  Figure out
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 7943b762c12d..de122354d09a 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -382,7 +382,7 @@ static ssize_t
 show_host_busy(struct device *dev, struct device_attribute *attr, char *buf)
 {
         struct Scsi_Host *shost = class_to_shost(dev);
-        return snprintf(buf, 20, "%d\n", atomic_read(&shost->host_busy));
+        return snprintf(buf, 20, "%d\n", scsi_host_busy(shost));
 }
 static DEVICE_ATTR(host_busy, S_IRUGO, show_host_busy, NULL);
 
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 53b485fe9b67..5ea06d310a25 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -758,6 +758,7 @@ extern void scsi_scan_host(struct Scsi_Host *);
 extern void scsi_rescan_device(struct device *);
 extern void scsi_remove_host(struct Scsi_Host *);
 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
+extern int scsi_host_busy(struct Scsi_Host *shost);
 extern void scsi_host_put(struct Scsi_Host *t);
 extern struct Scsi_Host *scsi_host_lookup(unsigned short);
 extern const char *scsi_host_state_name(enum scsi_host_state);