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>

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,

drivers/scsi/hosts.c

@@ -563,6 +563,16 @@ 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.

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);
 }
 

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));
 
 	/*

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;

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);
 }
 

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);
 		}
 	}

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

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);
 

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);