vfio/ccw: Use functions for alloc/free of the vfio_ccw_private

Makes the code easier to understand what is memory lifecycle and what is
other stuff.
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v4-cea4f5bd2c00+b52-ccw_mdev_jgg@nvidia.comSigned-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/s390/cio/vfio_ccw_drv.c

@@ -137,77 +137,107 @@ static void vfio_ccw_sch_irq(struct subchannel *sch)
 	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INTERRUPT);
 }
 
-static void vfio_ccw_free_regions(struct vfio_ccw_private *private)
+static struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch)
 {
-	if (private->crw_region)
-		kmem_cache_free(vfio_ccw_crw_region, private->crw_region);
-	if (private->schib_region)
-		kmem_cache_free(vfio_ccw_schib_region, private->schib_region);
-	if (private->cmd_region)
-		kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region);
-	if (private->io_region)
-		kmem_cache_free(vfio_ccw_io_region, private->io_region);
-}
-
-static int vfio_ccw_sch_probe(struct subchannel *sch)
-{
-	struct pmcw *pmcw = &sch->schib.pmcw;
 	struct vfio_ccw_private *private;
-	int ret = -ENOMEM;
-
-	if (pmcw->qf) {
-		dev_warn(&sch->dev, "vfio: ccw: does not support QDIO: %s\n",
-			 dev_name(&sch->dev));
-		return -ENODEV;
-	}
 
 	private = kzalloc(sizeof(*private), GFP_KERNEL);
 	if (!private)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
+
+	private->sch = sch;
+	mutex_init(&private->io_mutex);
+	private->state = VFIO_CCW_STATE_NOT_OPER;
+	INIT_LIST_HEAD(&private->crw);
+	INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo);
+	INIT_WORK(&private->crw_work, vfio_ccw_crw_todo);
+	atomic_set(&private->avail, 1);
 
 	private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX, sizeof(struct ccw1),
 				       GFP_KERNEL);
 	if (!private->cp.guest_cp)
-		goto out_free;
+		goto out_free_private;
 
 	private->io_region = kmem_cache_zalloc(vfio_ccw_io_region,
 					       GFP_KERNEL | GFP_DMA);
 	if (!private->io_region)
-		goto out_free;
+		goto out_free_cp;
 
 	private->cmd_region = kmem_cache_zalloc(vfio_ccw_cmd_region,
 						GFP_KERNEL | GFP_DMA);
 	if (!private->cmd_region)
-		goto out_free;
+		goto out_free_io;
 
 	private->schib_region = kmem_cache_zalloc(vfio_ccw_schib_region,
 						  GFP_KERNEL | GFP_DMA);
 
 	if (!private->schib_region)
-		goto out_free;
+		goto out_free_cmd;
 
 	private->crw_region = kmem_cache_zalloc(vfio_ccw_crw_region,
 						GFP_KERNEL | GFP_DMA);
 
 	if (!private->crw_region)
-		goto out_free;
+		goto out_free_schib;
+	return private;
+
+out_free_schib:
+	kmem_cache_free(vfio_ccw_schib_region, private->schib_region);
+out_free_cmd:
+	kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region);
+out_free_io:
+	kmem_cache_free(vfio_ccw_io_region, private->io_region);
+out_free_cp:
+	kfree(private->cp.guest_cp);
+out_free_private:
+	mutex_destroy(&private->io_mutex);
+	kfree(private);
+	return ERR_PTR(-ENOMEM);
+}
+
+static void vfio_ccw_free_private(struct vfio_ccw_private *private)
+{
+	struct vfio_ccw_crw *crw, *temp;
+
+	list_for_each_entry_safe(crw, temp, &private->crw, next) {
+		list_del(&crw->next);
+		kfree(crw);
+	}
+
+	kmem_cache_free(vfio_ccw_crw_region, private->crw_region);
+	kmem_cache_free(vfio_ccw_schib_region, private->schib_region);
+	kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region);
+	kmem_cache_free(vfio_ccw_io_region, private->io_region);
+	kfree(private->cp.guest_cp);
+	mutex_destroy(&private->io_mutex);
+	kfree(private);
+}
+
+static int vfio_ccw_sch_probe(struct subchannel *sch)
+{
+	struct pmcw *pmcw = &sch->schib.pmcw;
+	struct vfio_ccw_private *private;
+	int ret = -ENOMEM;
+
+	if (pmcw->qf) {
+		dev_warn(&sch->dev, "vfio: ccw: does not support QDIO: %s\n",
+			 dev_name(&sch->dev));
+		return -ENODEV;
+	}
+
+	private = vfio_ccw_alloc_private(sch);
+	if (IS_ERR(private))
+		return PTR_ERR(private);
 
-	private->sch = sch;
 	dev_set_drvdata(&sch->dev, private);
-	mutex_init(&private->io_mutex);
 
 	spin_lock_irq(sch->lock);
-	private->state = VFIO_CCW_STATE_NOT_OPER;
 	sch->isc = VFIO_CCW_ISC;
 	ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
 	spin_unlock_irq(sch->lock);
 	if (ret)
 		goto out_free;
 
-	INIT_LIST_HEAD(&private->crw);
-	INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo);
-	INIT_WORK(&private->crw_work, vfio_ccw_crw_todo);
-	atomic_set(&private->avail, 1);
 	private->state = VFIO_CCW_STATE_STANDBY;
 
 	ret = vfio_ccw_mdev_reg(sch);
@@ -228,31 +258,20 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 	cio_disable_subchannel(sch);
 out_free:
 	dev_set_drvdata(&sch->dev, NULL);
-	vfio_ccw_free_regions(private);
-	kfree(private->cp.guest_cp);
-	kfree(private);
+	vfio_ccw_free_private(private);
 	return ret;
 }
 
 static void vfio_ccw_sch_remove(struct subchannel *sch)
 {
 	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
-	struct vfio_ccw_crw *crw, *temp;
 
 	vfio_ccw_sch_quiesce(sch);
-
-	list_for_each_entry_safe(crw, temp, &private->crw, next) {
-		list_del(&crw->next);
-		kfree(crw);
-	}
-
 	vfio_ccw_mdev_unreg(sch);
 
 	dev_set_drvdata(&sch->dev, NULL);
 
-	vfio_ccw_free_regions(private);
-	kfree(private->cp.guest_cp);
-	kfree(private);
+	vfio_ccw_free_private(private);
 
 	VFIO_CCW_MSG_EVENT(4, "unbound from subchannel %x.%x.%04x\n",
 			   sch->schid.cssid, sch->schid.ssid,