libnvdimm: Make remove callback return void

All drivers return 0 in their remove callback and the driver core ignores
the return value of nvdimm_bus_remove() anyhow. So simplify by changing
the driver remove callback to return void and return 0 unconditionally
to the upper layer.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210212171043.2136580-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/dax/pmem/compat.c

@@ -41,10 +41,9 @@ static int dax_pmem_compat_release(struct device *dev, void *data)
 	return 0;
 }
 
-static int dax_pmem_compat_remove(struct device *dev)
+static void dax_pmem_compat_remove(struct device *dev)
 {
 	device_for_each_child(dev, NULL, dax_pmem_compat_release);
-	return 0;
 }
 
 static struct nd_device_driver dax_pmem_compat_driver = {

drivers/nvdimm/blk.c

@@ -310,11 +310,10 @@ static int nd_blk_probe(struct device *dev)
 		return nsblk_attach_disk(nsblk);
 }
 
-static int nd_blk_remove(struct device *dev)
+static void nd_blk_remove(struct device *dev)
 {
 	if (is_nd_btt(dev))
 		nvdimm_namespace_detach_btt(to_nd_btt(dev));
-	return 0;
 }
 
 static struct nd_device_driver nd_blk_driver = {

drivers/nvdimm/bus.c

@@ -113,18 +113,17 @@ static int nvdimm_bus_remove(struct device *dev)
 	struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
 	struct module *provider = to_bus_provider(dev);
 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
-	int rc = 0;
 
 	if (nd_drv->remove) {
 		debug_nvdimm_lock(dev);
-		rc = nd_drv->remove(dev);
+		nd_drv->remove(dev);
 		debug_nvdimm_unlock(dev);
 	}
 
-	dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
-			dev_name(dev), rc);
+	dev_dbg(&nvdimm_bus->dev, "%s.remove(%s)\n", dev->driver->name,
+			dev_name(dev));
 	module_put(provider);
-	return rc;
+	return 0;
 }
 
 static void nvdimm_bus_shutdown(struct device *dev)
@@ -427,7 +426,7 @@ static void free_badrange_list(struct list_head *badrange_list)
 	list_del_init(badrange_list);
 }
 
-static int nd_bus_remove(struct device *dev)
+static void nd_bus_remove(struct device *dev)
 {
 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 
@@ -446,8 +445,6 @@ static int nd_bus_remove(struct device *dev)
 	spin_unlock(&nvdimm_bus->badrange.lock);
 
 	nvdimm_bus_destroy_ndctl(nvdimm_bus);
-
-	return 0;
 }
 
 static int nd_bus_probe(struct device *dev)

drivers/nvdimm/dimm.c

@@ -113,7 +113,7 @@ static int nvdimm_probe(struct device *dev)
 	return rc;
 }
 
-static int nvdimm_remove(struct device *dev)
+static void nvdimm_remove(struct device *dev)
 {
 	struct nvdimm_drvdata *ndd = dev_get_drvdata(dev);
 
@@ -121,8 +121,6 @@ static int nvdimm_remove(struct device *dev)
 	dev_set_drvdata(dev, NULL);
 	nvdimm_bus_unlock(dev);
 	put_ndd(ndd);
-
-	return 0;
 }
 
 static struct nd_device_driver nvdimm_driver = {

drivers/nvdimm/pmem.c

@@ -564,7 +564,7 @@ static int nd_pmem_probe(struct device *dev)
 	return pmem_attach_disk(dev, ndns);
 }
 
-static int nd_pmem_remove(struct device *dev)
+static void nd_pmem_remove(struct device *dev)
 {
 	struct pmem_device *pmem = dev_get_drvdata(dev);
 
@@ -579,8 +579,6 @@ static int nd_pmem_remove(struct device *dev)
 		pmem->bb_state = NULL;
 	}
 	nvdimm_flush(to_nd_region(dev->parent), NULL);
-
-	return 0;
 }
 
 static void nd_pmem_shutdown(struct device *dev)

drivers/nvdimm/region.c

@@ -87,7 +87,7 @@ static int child_unregister(struct device *dev, void *data)
 	return 0;
 }
 
-static int nd_region_remove(struct device *dev)
+static void nd_region_remove(struct device *dev)
 {
 	struct nd_region *nd_region = to_nd_region(dev);
 
@@ -108,8 +108,6 @@ static int nd_region_remove(struct device *dev)
 	 */
 	sysfs_put(nd_region->bb_state);
 	nd_region->bb_state = NULL;
-
-	return 0;
 }
 
 static int child_notify(struct device *dev, void *data)

include/linux/nd.h

@@ -26,7 +26,7 @@ struct nd_device_driver {
 	struct device_driver drv;
 	unsigned long type;
 	int (*probe)(struct device *dev);
-	int (*remove)(struct device *dev);
+	void (*remove)(struct device *dev);
 	void (*shutdown)(struct device *dev);
 	void (*notify)(struct device *dev, enum nvdimm_event event);
 };