Merge tag 'libnvdimm-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm and device-dax updates from Dan Williams:

- Fix the error code polarity for the device-dax/mapping attribute

- For the device-dax and libnvdimm bus implementations stop
implementing a useless return code for the remove() callback.

- Miscellaneous cleanups

* tag 'libnvdimm-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
dax-device: Make remove callback return void
device-dax: Drop an empty .remove callback
device-dax: Fix error path in dax_driver_register
device-dax: Properly handle drivers without remove callback
device-dax: Prevent registering drivers without probe callback
libnvdimm: Make remove callback return void
libnvdimm/dimm: Simplify nvdimm_remove()
device-dax: Fix default return code of range_parse()

drivers/dax/bus.c

···
 	struct dax_device_driver *dax_drv = to_dax_drv(dev->driver);
 	struct dev_dax *dev_dax = to_dev_dax(dev);
 
-	return dax_drv->remove(dev_dax);
+	if (dax_drv->remove)
+		dax_drv->remove(dev_dax);
+
+	return 0;
 }
 
 static struct bus_type dax_bus_type = {
···
 {
 	unsigned long long addr = 0;
 	char *start, *end, *str;
-	ssize_t rc = EINVAL;
+	ssize_t rc = -EINVAL;
 
 	str = kstrdup(opt, GFP_KERNEL);
 	if (!str)
···
 	struct device_driver *drv = &dax_drv->drv;
 	int rc = 0;
 
+	/*
+	 * dax_bus_probe() calls dax_drv->probe() unconditionally.
+	 * So better be safe than sorry and ensure it is provided.
+	 */
+	if (!dax_drv->probe)
+		return -EINVAL;
+
 	INIT_LIST_HEAD(&dax_drv->ids);
 	drv->owner = module;
 	drv->name = mod_name;
···
 	mutex_unlock(&dax_bus_lock);
 	if (rc)
 		return rc;
-	return driver_register(drv);
+
+	rc = driver_register(drv);
+	if (rc && dax_drv->match_always) {
+		mutex_lock(&dax_bus_lock);
+		match_always_count -= dax_drv->match_always;
+		mutex_unlock(&dax_bus_lock);
+	}
+
+	return rc;
 }
 EXPORT_SYMBOL_GPL(__dax_driver_register);
 

drivers/dax/bus.h

···
 	struct list_head ids;
 	int match_always;
 	int (*probe)(struct dev_dax *dev);
-	int (*remove)(struct dev_dax *dev);
+	void (*remove)(struct dev_dax *dev);
 };
 
 int __dax_driver_register(struct dax_device_driver *dax_drv,

drivers/dax/device.c

···
 }
 EXPORT_SYMBOL_GPL(dev_dax_probe);
 
-static int dev_dax_remove(struct dev_dax *dev_dax)
-{
-	/* all probe actions are unwound by devm */
-	return 0;
-}
-
 static struct dax_device_driver device_dax_driver = {
 	.probe = dev_dax_probe,
-	.remove = dev_dax_remove,
+	/* all probe actions are unwound by devm, so .remove isn't necessary */
 	.match_always = 1,
 };
 

drivers/dax/kmem.c

···
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
-static int dev_dax_kmem_remove(struct dev_dax *dev_dax)
+static void dev_dax_kmem_remove(struct dev_dax *dev_dax)
 {
 	int i, success = 0;
 	struct device *dev = &dev_dax->dev;
···
 		kfree(data);
 		dev_set_drvdata(dev, NULL);
 	}
-
-	return 0;
 }
 #else
-static int dev_dax_kmem_remove(struct dev_dax *dev_dax)
+static void dev_dax_kmem_remove(struct dev_dax *dev_dax)
 {
 	/*
 	 * Without hotremove purposely leak the request_mem_region() for the
···
 	 * request_mem_region().
 	 */
 	any_hotremove_failed = true;
-	return 0;
 }
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 

drivers/dax/pmem/compat.c

···
 	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

···
 		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

···
 	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)
···
 	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);
 
···
 	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

···
 	return rc;
 }
 
-static int nvdimm_remove(struct device *dev)
+static void nvdimm_remove(struct device *dev)
 {
 	struct nvdimm_drvdata *ndd = dev_get_drvdata(dev);
-
-	if (!ndd)
-		return 0;
 
 	nvdimm_bus_lock(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

···
 	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);
 
···
 		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

···
 	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);
 
···
 	 */
 	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

···
 	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);
 };