// SPDX-License-Identifier: GPL-2.0-only

  /*
   * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.

   */
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

  #include <linux/libnvdimm.h>

  #include <linux/sched/mm.h>

  #include <linux/vmalloc.h>

  #include <linux/uaccess.h>

  #include <linux/module.h>

  #include <linux/blkdev.h>

  #include <linux/fcntl.h>

  #include <linux/async.h>

  #include <linux/genhd.h>

  #include <linux/ndctl.h>

  #include <linux/sched.h>

  #include <linux/slab.h>

  #include <linux/cpu.h>

  #include <linux/fs.h>
  #include <linux/io.h>

  #include <linux/mm.h>

  #include <linux/nd.h>

  #include "nd-core.h"

  #include "nd.h"

  #include "pfn.h"

  int nvdimm_major;

  static int nvdimm_bus_major;

  struct class *nd_class;

  static DEFINE_IDA(nd_ida);

  static int to_nd_device_type(struct device *dev)
  {
  	if (is_nvdimm(dev))
  		return ND_DEVICE_DIMM;

  	else if (is_memory(dev))

  		return ND_DEVICE_REGION_PMEM;
  	else if (is_nd_blk(dev))
  		return ND_DEVICE_REGION_BLK;

  	else if (is_nd_dax(dev))
  		return ND_DEVICE_DAX_PMEM;

  	else if (is_nd_region(dev->parent))

  		return nd_region_to_nstype(to_nd_region(dev->parent));

  
  	return 0;
  }
  
  static int nvdimm_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
  {
  	return add_uevent_var(env, "MODALIAS=" ND_DEVICE_MODALIAS_FMT,
  			to_nd_device_type(dev));
  }

  static struct module *to_bus_provider(struct device *dev)
  {
  	/* pin bus providers while regions are enabled */

  	if (is_nd_region(dev)) {

  		struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);

  		return nvdimm_bus->nd_desc->module;

  	}
  	return NULL;
  }

  static void nvdimm_bus_probe_start(struct nvdimm_bus *nvdimm_bus)
  {
  	nvdimm_bus_lock(&nvdimm_bus->dev);
  	nvdimm_bus->probe_active++;
  	nvdimm_bus_unlock(&nvdimm_bus->dev);
  }
  
  static void nvdimm_bus_probe_end(struct nvdimm_bus *nvdimm_bus)
  {
  	nvdimm_bus_lock(&nvdimm_bus->dev);
  	if (--nvdimm_bus->probe_active == 0)

  		wake_up(&nvdimm_bus->wait);

  	nvdimm_bus_unlock(&nvdimm_bus->dev);
  }

  static int nvdimm_bus_probe(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;

  	if (!try_module_get(provider))
  		return -ENXIO;

  	dev_dbg(&nvdimm_bus->dev, "START: %s.probe(%s)
  ",
  			dev->driver->name, dev_name(dev));

  	nvdimm_bus_probe_start(nvdimm_bus);

  	debug_nvdimm_lock(dev);

  	rc = nd_drv->probe(dev);

  	debug_nvdimm_unlock(dev);

  	if ((rc == 0 || rc == -EOPNOTSUPP) &&
  			dev->parent && is_nd_region(dev->parent))

  		nd_region_advance_seeds(to_nd_region(dev->parent), dev);

  	nvdimm_bus_probe_end(nvdimm_bus);

  	dev_dbg(&nvdimm_bus->dev, "END: %s.probe(%s) = %d
  ", dev->driver->name,

  			dev_name(dev), rc);

  	if (rc != 0)
  		module_put(provider);

  	return rc;
  }
  
  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);

  		debug_nvdimm_unlock(dev);
  	}

  	dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d
  ", dev->driver->name,
  			dev_name(dev), rc);

  	module_put(provider);

  	return rc;
  }

  static void nvdimm_bus_shutdown(struct device *dev)
  {
  	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  	struct nd_device_driver *nd_drv = NULL;
  
  	if (dev->driver)
  		nd_drv = to_nd_device_driver(dev->driver);
  
  	if (nd_drv && nd_drv->shutdown) {
  		nd_drv->shutdown(dev);
  		dev_dbg(&nvdimm_bus->dev, "%s.shutdown(%s)
  ",
  				dev->driver->name, dev_name(dev));
  	}
  }

  void nd_device_notify(struct device *dev, enum nvdimm_event event)
  {

  	nd_device_lock(dev);

  	if (dev->driver) {
  		struct nd_device_driver *nd_drv;
  
  		nd_drv = to_nd_device_driver(dev->driver);
  		if (nd_drv->notify)
  			nd_drv->notify(dev, event);
  	}

  	nd_device_unlock(dev);

  }
  EXPORT_SYMBOL(nd_device_notify);
  
  void nvdimm_region_notify(struct nd_region *nd_region, enum nvdimm_event event)
  {
  	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
  
  	if (!nvdimm_bus)
  		return;
  
  	/* caller is responsible for holding a reference on the device */
  	nd_device_notify(&nd_region->dev, event);
  }
  EXPORT_SYMBOL_GPL(nvdimm_region_notify);

  struct clear_badblocks_context {
  	resource_size_t phys, cleared;
  };
  
  static int nvdimm_clear_badblocks_region(struct device *dev, void *data)
  {
  	struct clear_badblocks_context *ctx = data;
  	struct nd_region *nd_region;
  	resource_size_t ndr_end;
  	sector_t sector;
  
  	/* make sure device is a region */

  	if (!is_memory(dev))

  		return 0;
  
  	nd_region = to_nd_region(dev);
  	ndr_end = nd_region->ndr_start + nd_region->ndr_size - 1;
  
  	/* make sure we are in the region */
  	if (ctx->phys < nd_region->ndr_start
  			|| (ctx->phys + ctx->cleared) > ndr_end)
  		return 0;
  
  	sector = (ctx->phys - nd_region->ndr_start) / 512;
  	badblocks_clear(&nd_region->bb, sector, ctx->cleared / 512);

  	if (nd_region->bb_state)
  		sysfs_notify_dirent(nd_region->bb_state);

  	return 0;
  }
  
  static void nvdimm_clear_badblocks_regions(struct nvdimm_bus *nvdimm_bus,
  		phys_addr_t phys, u64 cleared)
  {
  	struct clear_badblocks_context ctx = {
  		.phys = phys,
  		.cleared = cleared,
  	};
  
  	device_for_each_child(&nvdimm_bus->dev, &ctx,
  			nvdimm_clear_badblocks_region);
  }
  
  static void nvdimm_account_cleared_poison(struct nvdimm_bus *nvdimm_bus,
  		phys_addr_t phys, u64 cleared)
  {
  	if (cleared > 0)

  		badrange_forget(&nvdimm_bus->badrange, phys, cleared);

  
  	if (cleared > 0 && cleared / 512)
  		nvdimm_clear_badblocks_regions(nvdimm_bus, phys, cleared);
  }

  long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
  		unsigned int len)
  {
  	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  	struct nvdimm_bus_descriptor *nd_desc;
  	struct nd_cmd_clear_error clear_err;
  	struct nd_cmd_ars_cap ars_cap;
  	u32 clear_err_unit, mask;

  	unsigned int noio_flag;

  	int cmd_rc, rc;
  
  	if (!nvdimm_bus)
  		return -ENXIO;
  
  	nd_desc = nvdimm_bus->nd_desc;

  	/*
  	 * if ndctl does not exist, it's PMEM_LEGACY and
  	 * we want to just pretend everything is handled.
  	 */

  	if (!nd_desc->ndctl)

  		return len;

  
  	memset(&ars_cap, 0, sizeof(ars_cap));
  	ars_cap.address = phys;
  	ars_cap.length = len;

  	noio_flag = memalloc_noio_save();

  	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, &ars_cap,
  			sizeof(ars_cap), &cmd_rc);

  	memalloc_noio_restore(noio_flag);

  	if (rc < 0)
  		return rc;
  	if (cmd_rc < 0)
  		return cmd_rc;
  	clear_err_unit = ars_cap.clear_err_unit;
  	if (!clear_err_unit || !is_power_of_2(clear_err_unit))
  		return -ENXIO;
  
  	mask = clear_err_unit - 1;
  	if ((phys | len) & mask)
  		return -ENXIO;
  	memset(&clear_err, 0, sizeof(clear_err));
  	clear_err.address = phys;
  	clear_err.length = len;

  	noio_flag = memalloc_noio_save();

  	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_CLEAR_ERROR, &clear_err,
  			sizeof(clear_err), &cmd_rc);

  	memalloc_noio_restore(noio_flag);

  	if (rc < 0)
  		return rc;
  	if (cmd_rc < 0)
  		return cmd_rc;

  	nvdimm_account_cleared_poison(nvdimm_bus, phys, clear_err.cleared);

  	return clear_err.cleared;
  }
  EXPORT_SYMBOL_GPL(nvdimm_clear_poison);

  static int nvdimm_bus_match(struct device *dev, struct device_driver *drv);

  static struct bus_type nvdimm_bus_type = {

  	.name = "nd",

  	.uevent = nvdimm_bus_uevent,
  	.match = nvdimm_bus_match,
  	.probe = nvdimm_bus_probe,
  	.remove = nvdimm_bus_remove,

  	.shutdown = nvdimm_bus_shutdown,

  };

  static void nvdimm_bus_release(struct device *dev)
  {
  	struct nvdimm_bus *nvdimm_bus;
  
  	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
  	ida_simple_remove(&nd_ida, nvdimm_bus->id);
  	kfree(nvdimm_bus);
  }

  bool is_nvdimm_bus(struct device *dev)

  {
  	return dev->release == nvdimm_bus_release;
  }
  
  struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
  {
  	struct device *dev;
  
  	for (dev = nd_dev; dev; dev = dev->parent)
  		if (is_nvdimm_bus(dev))
  			break;
  	dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus
  ");
  	if (dev)
  		return to_nvdimm_bus(dev);
  	return NULL;
  }
  
  struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
  {
  	struct nvdimm_bus *nvdimm_bus;
  
  	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
  	WARN_ON(!is_nvdimm_bus(dev));
  	return nvdimm_bus;
  }
  EXPORT_SYMBOL_GPL(to_nvdimm_bus);

  struct nvdimm_bus *nvdimm_to_bus(struct nvdimm *nvdimm)
  {
  	return to_nvdimm_bus(nvdimm->dev.parent);
  }
  EXPORT_SYMBOL_GPL(nvdimm_to_bus);

  struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
  		struct nvdimm_bus_descriptor *nd_desc)
  {
  	struct nvdimm_bus *nvdimm_bus;
  	int rc;
  
  	nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
  	if (!nvdimm_bus)
  		return NULL;
  	INIT_LIST_HEAD(&nvdimm_bus->list);
  	INIT_LIST_HEAD(&nvdimm_bus->mapping_list);

  	init_waitqueue_head(&nvdimm_bus->wait);

  	nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);

  	if (nvdimm_bus->id < 0) {
  		kfree(nvdimm_bus);
  		return NULL;
  	}

  	mutex_init(&nvdimm_bus->reconfig_mutex);
  	badrange_init(&nvdimm_bus->badrange);

  	nvdimm_bus->nd_desc = nd_desc;
  	nvdimm_bus->dev.parent = parent;
  	nvdimm_bus->dev.release = nvdimm_bus_release;
  	nvdimm_bus->dev.groups = nd_desc->attr_groups;
  	nvdimm_bus->dev.bus = &nvdimm_bus_type;

  	nvdimm_bus->dev.of_node = nd_desc->of_node;

  	dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
  	rc = device_register(&nvdimm_bus->dev);
  	if (rc) {
  		dev_dbg(&nvdimm_bus->dev, "registration failed: %d
  ", rc);
  		goto err;
  	}
  
  	return nvdimm_bus;
   err:
  	put_device(&nvdimm_bus->dev);
  	return NULL;
  }
  EXPORT_SYMBOL_GPL(nvdimm_bus_register);
  
  void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
  {
  	if (!nvdimm_bus)
  		return;
  	device_unregister(&nvdimm_bus->dev);
  }
  EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
  
  static int child_unregister(struct device *dev, void *data)
  {
  	/*
  	 * the singular ndctl class device per bus needs to be
  	 * "device_destroy"ed, so skip it here
  	 *
  	 * i.e. remove classless children
  	 */
  	if (dev->class)

  		return 0;
  
  	if (is_nvdimm(dev)) {
  		struct nvdimm *nvdimm = to_nvdimm(dev);
  		bool dev_put = false;
  
  		/* We are shutting down. Make state frozen artificially. */
  		nvdimm_bus_lock(dev);

  		set_bit(NVDIMM_SECURITY_FROZEN, &nvdimm->sec.flags);

  		if (test_and_clear_bit(NDD_WORK_PENDING, &nvdimm->flags))
  			dev_put = true;
  		nvdimm_bus_unlock(dev);
  		cancel_delayed_work_sync(&nvdimm->dwork);
  		if (dev_put)
  			put_device(dev);
  	}
  	nd_device_unregister(dev, ND_SYNC);

  	return 0;
  }

  static void free_badrange_list(struct list_head *badrange_list)

  {

  	struct badrange_entry *bre, *next;

  	list_for_each_entry_safe(bre, next, badrange_list, list) {
  		list_del(&bre->list);
  		kfree(bre);

  	}

  	list_del_init(badrange_list);

  }
  
  static int nd_bus_remove(struct device *dev)
  {
  	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
  
  	mutex_lock(&nvdimm_bus_list_mutex);
  	list_del_init(&nvdimm_bus->list);
  	mutex_unlock(&nvdimm_bus_list_mutex);

  	wait_event(nvdimm_bus->wait,
  			atomic_read(&nvdimm_bus->ioctl_active) == 0);

  	nd_synchronize();
  	device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);

  	spin_lock(&nvdimm_bus->badrange.lock);
  	free_badrange_list(&nvdimm_bus->badrange.list);
  	spin_unlock(&nvdimm_bus->badrange.lock);

  
  	nvdimm_bus_destroy_ndctl(nvdimm_bus);
  
  	return 0;
  }
  
  static int nd_bus_probe(struct device *dev)
  {
  	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
  	int rc;
  
  	rc = nvdimm_bus_create_ndctl(nvdimm_bus);
  	if (rc)
  		return rc;
  
  	mutex_lock(&nvdimm_bus_list_mutex);
  	list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
  	mutex_unlock(&nvdimm_bus_list_mutex);
  
  	/* enable bus provider attributes to look up their local context */
  	dev_set_drvdata(dev, nvdimm_bus->nd_desc);
  
  	return 0;
  }
  
  static struct nd_device_driver nd_bus_driver = {
  	.probe = nd_bus_probe,
  	.remove = nd_bus_remove,
  	.drv = {
  		.name = "nd_bus",
  		.suppress_bind_attrs = true,
  		.bus = &nvdimm_bus_type,
  		.owner = THIS_MODULE,
  		.mod_name = KBUILD_MODNAME,
  	},

  };

  static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
  {
  	struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
  
  	if (is_nvdimm_bus(dev) && nd_drv == &nd_bus_driver)
  		return true;
  
  	return !!test_bit(to_nd_device_type(dev), &nd_drv->type);
  }

  static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
  
  void nd_synchronize(void)
  {
  	async_synchronize_full_domain(&nd_async_domain);
  }
  EXPORT_SYMBOL_GPL(nd_synchronize);
  
  static void nd_async_device_register(void *d, async_cookie_t cookie)
  {
  	struct device *dev = d;
  
  	if (device_add(dev) != 0) {
  		dev_err(dev, "%s: failed
  ", __func__);
  		put_device(dev);
  	}
  	put_device(dev);

  	if (dev->parent)
  		put_device(dev->parent);

  }
  
  static void nd_async_device_unregister(void *d, async_cookie_t cookie)
  {
  	struct device *dev = d;

  	/* flush bus operations before delete */
  	nvdimm_bus_lock(dev);
  	nvdimm_bus_unlock(dev);

  	device_unregister(dev);
  	put_device(dev);
  }

  void __nd_device_register(struct device *dev)

  {

  	if (!dev)
  		return;

  
  	/*
  	 * Ensure that region devices always have their NUMA node set as
  	 * early as possible. This way we are able to make certain that
  	 * any memory associated with the creation and the creation
  	 * itself of the region is associated with the correct node.
  	 */
  	if (is_nd_region(dev))
  		set_dev_node(dev, to_nd_region(dev)->numa_node);

  	dev->bus = &nvdimm_bus_type;

  	if (dev->parent) {

  		get_device(dev->parent);

  		if (dev_to_node(dev) == NUMA_NO_NODE)
  			set_dev_node(dev, dev_to_node(dev->parent));
  	}

  	get_device(dev);

  
  	async_schedule_dev_domain(nd_async_device_register, dev,
  				  &nd_async_domain);

  }

  
  void nd_device_register(struct device *dev)
  {
  	device_initialize(dev);
  	__nd_device_register(dev);
  }

  EXPORT_SYMBOL(nd_device_register);
  
  void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
  {

  	bool killed;

  	switch (mode) {
  	case ND_ASYNC:

  		/*
  		 * In the async case this is being triggered with the
  		 * device lock held and the unregistration work needs to
  		 * be moved out of line iff this is thread has won the
  		 * race to schedule the deletion.
  		 */
  		if (!kill_device(dev))
  			return;

  		get_device(dev);
  		async_schedule_domain(nd_async_device_unregister, dev,
  				&nd_async_domain);
  		break;
  	case ND_SYNC:

  		/*
  		 * In the sync case the device is being unregistered due
  		 * to a state change of the parent. Claim the kill state
  		 * to synchronize against other unregistration requests,
  		 * or otherwise let the async path handle it if the
  		 * unregistration was already queued.
  		 */

  		nd_device_lock(dev);

  		killed = kill_device(dev);

  		nd_device_unlock(dev);

  
  		if (!killed)
  			return;

  		nd_synchronize();
  		device_unregister(dev);
  		break;
  	}
  }
  EXPORT_SYMBOL(nd_device_unregister);
  
  /**
   * __nd_driver_register() - register a region or a namespace driver
   * @nd_drv: driver to register
   * @owner: automatically set by nd_driver_register() macro
   * @mod_name: automatically set by nd_driver_register() macro
   */
  int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
  		const char *mod_name)
  {
  	struct device_driver *drv = &nd_drv->drv;
  
  	if (!nd_drv->type) {

  		pr_debug("driver type bitmask not set (%ps)
  ",

  				__builtin_return_address(0));
  		return -EINVAL;
  	}

  	if (!nd_drv->probe) {
  		pr_debug("%s ->probe() must be specified
  ", mod_name);

  		return -EINVAL;
  	}
  
  	drv->bus = &nvdimm_bus_type;
  	drv->owner = owner;
  	drv->mod_name = mod_name;
  
  	return driver_register(drv);
  }
  EXPORT_SYMBOL(__nd_driver_register);

  int nvdimm_revalidate_disk(struct gendisk *disk)
  {

  	struct device *dev = disk_to_dev(disk)->parent;

  	struct nd_region *nd_region = to_nd_region(dev->parent);

  	int disk_ro = get_disk_ro(disk);

  	/*
  	 * Upgrade to read-only if the region is read-only preserve as
  	 * read-only if the disk is already read-only.
  	 */
  	if (disk_ro || nd_region->ro == disk_ro)

  		return 0;

  	dev_info(dev, "%s read-only, marking %s read-only
  ",
  			dev_name(&nd_region->dev), disk->disk_name);
  	set_disk_ro(disk, 1);

  
  	return 0;
  
  }
  EXPORT_SYMBOL(nvdimm_revalidate_disk);

  static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	return sprintf(buf, ND_DEVICE_MODALIAS_FMT "
  ",
  			to_nd_device_type(dev));
  }
  static DEVICE_ATTR_RO(modalias);
  
  static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	return sprintf(buf, "%s
  ", dev->type->name);
  }
  static DEVICE_ATTR_RO(devtype);
  
  static struct attribute *nd_device_attributes[] = {
  	&dev_attr_modalias.attr,
  	&dev_attr_devtype.attr,
  	NULL,
  };

  /*

   * nd_device_attribute_group - generic attributes for all devices on an nd bus
   */
  struct attribute_group nd_device_attribute_group = {
  	.attrs = nd_device_attributes,

  };

  EXPORT_SYMBOL_GPL(nd_device_attribute_group);

  static ssize_t numa_node_show(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	return sprintf(buf, "%d
  ", dev_to_node(dev));
  }
  static DEVICE_ATTR_RO(numa_node);
  
  static struct attribute *nd_numa_attributes[] = {
  	&dev_attr_numa_node.attr,
  	NULL,
  };
  
  static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
  		int n)
  {
  	if (!IS_ENABLED(CONFIG_NUMA))
  		return 0;
  
  	return a->mode;
  }

  /*

   * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
   */
  struct attribute_group nd_numa_attribute_group = {
  	.attrs = nd_numa_attributes,
  	.is_visible = nd_numa_attr_visible,
  };
  EXPORT_SYMBOL_GPL(nd_numa_attribute_group);

  int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
  {
  	dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
  	struct device *dev;
  
  	dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
  			"ndctl%d", nvdimm_bus->id);

  	if (IS_ERR(dev))

  		dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld
  ",
  				nvdimm_bus->id, PTR_ERR(dev));

  	return PTR_ERR_OR_ZERO(dev);

  }
  
  void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
  {
  	device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
  }

  static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
  	[ND_CMD_IMPLEMENTED] = { },
  	[ND_CMD_SMART] = {
  		.out_num = 2,

  		.out_sizes = { 4, 128, },

  	},
  	[ND_CMD_SMART_THRESHOLD] = {
  		.out_num = 2,
  		.out_sizes = { 4, 8, },
  	},
  	[ND_CMD_DIMM_FLAGS] = {
  		.out_num = 2,
  		.out_sizes = { 4, 4 },
  	},
  	[ND_CMD_GET_CONFIG_SIZE] = {
  		.out_num = 3,
  		.out_sizes = { 4, 4, 4, },
  	},
  	[ND_CMD_GET_CONFIG_DATA] = {
  		.in_num = 2,
  		.in_sizes = { 4, 4, },
  		.out_num = 2,
  		.out_sizes = { 4, UINT_MAX, },
  	},
  	[ND_CMD_SET_CONFIG_DATA] = {
  		.in_num = 3,
  		.in_sizes = { 4, 4, UINT_MAX, },
  		.out_num = 1,
  		.out_sizes = { 4, },
  	},
  	[ND_CMD_VENDOR] = {
  		.in_num = 3,
  		.in_sizes = { 4, 4, UINT_MAX, },
  		.out_num = 3,
  		.out_sizes = { 4, 4, UINT_MAX, },
  	},

  	[ND_CMD_CALL] = {
  		.in_num = 2,
  		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
  		.out_num = 1,
  		.out_sizes = { UINT_MAX, },
  	},

  };
  
  const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
  {
  	if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
  		return &__nd_cmd_dimm_descs[cmd];
  	return NULL;
  }
  EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
  
  static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
  	[ND_CMD_IMPLEMENTED] = { },
  	[ND_CMD_ARS_CAP] = {
  		.in_num = 2,
  		.in_sizes = { 8, 8, },

  		.out_num = 4,
  		.out_sizes = { 4, 4, 4, 4, },

  	},
  	[ND_CMD_ARS_START] = {

  		.in_num = 5,
  		.in_sizes = { 8, 8, 2, 1, 5, },
  		.out_num = 2,
  		.out_sizes = { 4, 4, },

  	},
  	[ND_CMD_ARS_STATUS] = {

  		.out_num = 3,
  		.out_sizes = { 4, 4, UINT_MAX, },

  	},

  	[ND_CMD_CLEAR_ERROR] = {
  		.in_num = 2,
  		.in_sizes = { 8, 8, },
  		.out_num = 3,
  		.out_sizes = { 4, 4, 8, },
  	},

  	[ND_CMD_CALL] = {
  		.in_num = 2,
  		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
  		.out_num = 1,
  		.out_sizes = { UINT_MAX, },
  	},

  };
  
  const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
  {
  	if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
  		return &__nd_cmd_bus_descs[cmd];
  	return NULL;
  }
  EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
  
  u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
  		const struct nd_cmd_desc *desc, int idx, void *buf)
  {
  	if (idx >= desc->in_num)
  		return UINT_MAX;
  
  	if (desc->in_sizes[idx] < UINT_MAX)
  		return desc->in_sizes[idx];
  
  	if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
  		struct nd_cmd_set_config_hdr *hdr = buf;
  
  		return hdr->in_length;
  	} else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
  		struct nd_cmd_vendor_hdr *hdr = buf;
  
  		return hdr->in_length;

  	} else if (cmd == ND_CMD_CALL) {
  		struct nd_cmd_pkg *pkg = buf;
  
  		return pkg->nd_size_in;

  	}
  
  	return UINT_MAX;
  }
  EXPORT_SYMBOL_GPL(nd_cmd_in_size);
  
  u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
  		const struct nd_cmd_desc *desc, int idx, const u32 *in_field,

  		const u32 *out_field, unsigned long remainder)

  {
  	if (idx >= desc->out_num)
  		return UINT_MAX;
  
  	if (desc->out_sizes[idx] < UINT_MAX)
  		return desc->out_sizes[idx];
  
  	if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
  		return in_field[1];
  	else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
  		return out_field[1];

  	else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 2) {
  		/*
  		 * Per table 9-276 ARS Data in ACPI 6.1, out_field[1] is
  		 * "Size of Output Buffer in bytes, including this
  		 * field."
  		 */
  		if (out_field[1] < 4)
  			return 0;
  		/*
  		 * ACPI 6.1 is ambiguous if 'status' is included in the
  		 * output size. If we encounter an output size that
  		 * overshoots the remainder by 4 bytes, assume it was
  		 * including 'status'.
  		 */

  		if (out_field[1] - 4 == remainder)

  			return remainder;

  		return out_field[1] - 8;

  	} else if (cmd == ND_CMD_CALL) {

  		struct nd_cmd_pkg *pkg = (struct nd_cmd_pkg *) in_field;
  
  		return pkg->nd_size_out;
  	}

  
  	return UINT_MAX;
  }
  EXPORT_SYMBOL_GPL(nd_cmd_out_size);

  void wait_nvdimm_bus_probe_idle(struct device *dev)

  {

  	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);

  	do {
  		if (nvdimm_bus->probe_active == 0)
  			break;

  		nvdimm_bus_unlock(dev);

  		nd_device_unlock(dev);

  		wait_event(nvdimm_bus->wait,

  				nvdimm_bus->probe_active == 0);

  		nd_device_lock(dev);

  		nvdimm_bus_lock(dev);

  	} while (true);
  }

  static int nd_pmem_forget_poison_check(struct device *dev, void *data)

  {

  	struct nd_cmd_clear_error *clear_err =
  		(struct nd_cmd_clear_error *)data;
  	struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
  	struct nd_pfn *nd_pfn = is_nd_pfn(dev) ? to_nd_pfn(dev) : NULL;
  	struct nd_dax *nd_dax = is_nd_dax(dev) ? to_nd_dax(dev) : NULL;
  	struct nd_namespace_common *ndns = NULL;
  	struct nd_namespace_io *nsio;
  	resource_size_t offset = 0, end_trunc = 0, start, end, pstart, pend;
  
  	if (nd_dax || !dev->driver)
  		return 0;
  
  	start = clear_err->address;
  	end = clear_err->address + clear_err->cleared - 1;
  
  	if (nd_btt || nd_pfn || nd_dax) {
  		if (nd_btt)
  			ndns = nd_btt->ndns;
  		else if (nd_pfn)
  			ndns = nd_pfn->ndns;
  		else if (nd_dax)
  			ndns = nd_dax->nd_pfn.ndns;
  
  		if (!ndns)
  			return 0;
  	} else
  		ndns = to_ndns(dev);
  
  	nsio = to_nd_namespace_io(&ndns->dev);
  	pstart = nsio->res.start + offset;
  	pend = nsio->res.end - end_trunc;
  
  	if ((pstart >= start) && (pend <= end))

  		return -EBUSY;

  	return 0;

  
  }
  
  static int nd_ns_forget_poison_check(struct device *dev, void *data)
  {
  	return device_for_each_child(dev, data, nd_pmem_forget_poison_check);

  }

  /* set_config requires an idle interleave set */

  static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,

  		struct nvdimm *nvdimm, unsigned int cmd, void *data)

  {

  	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
  
  	/* ask the bus provider if it would like to block this request */
  	if (nd_desc->clear_to_send) {

  		int rc = nd_desc->clear_to_send(nd_desc, nvdimm, cmd, data);

  
  		if (rc)
  			return rc;
  	}

  	/* require clear error to go through the pmem driver */
  	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR)

  		return device_for_each_child(&nvdimm_bus->dev, data,
  				nd_ns_forget_poison_check);

  	if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
  		return 0;

  	/* prevent label manipulation while the kernel owns label updates */

  	wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);

  	if (atomic_read(&nvdimm->busy))
  		return -EBUSY;
  	return 0;
  }

  static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
  		int read_only, unsigned int ioctl_cmd, unsigned long arg)
  {
  	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;

  	const struct nd_cmd_desc *desc = NULL;
  	unsigned int cmd = _IOC_NR(ioctl_cmd);

  	struct device *dev = &nvdimm_bus->dev;

  	void __user *p = (void __user *) arg;

  	char *out_env = NULL, *in_env = NULL;

  	const char *cmd_name, *dimm_name;

  	u32 in_len = 0, out_len = 0;
  	unsigned int func = cmd;

  	unsigned long cmd_mask;

  	struct nd_cmd_pkg pkg;

  	int rc, i, cmd_rc;

  	void *buf = NULL;

  	u64 buf_len = 0;

  
  	if (nvdimm) {
  		desc = nd_cmd_dimm_desc(cmd);
  		cmd_name = nvdimm_cmd_name(cmd);

  		cmd_mask = nvdimm->cmd_mask;

  		dimm_name = dev_name(&nvdimm->dev);
  	} else {
  		desc = nd_cmd_bus_desc(cmd);
  		cmd_name = nvdimm_bus_cmd_name(cmd);

  		cmd_mask = nd_desc->cmd_mask;

  		dimm_name = "bus";
  	}

  	if (cmd == ND_CMD_CALL) {
  		if (copy_from_user(&pkg, p, sizeof(pkg)))
  			return -EFAULT;
  	}

  	if (!desc || (desc->out_num + desc->in_num == 0) ||

  			!test_bit(cmd, &cmd_mask))

  		return -ENOTTY;
  
  	/* fail write commands (when read-only) */
  	if (read_only)

  		switch (cmd) {
  		case ND_CMD_VENDOR:
  		case ND_CMD_SET_CONFIG_DATA:
  		case ND_CMD_ARS_START:

  		case ND_CMD_CLEAR_ERROR:

  		case ND_CMD_CALL:

  			dev_dbg(dev, "'%s' command while read-only.
  ",

  					nvdimm ? nvdimm_cmd_name(cmd)
  					: nvdimm_bus_cmd_name(cmd));
  			return -EPERM;
  		default:
  			break;
  		}
  
  	/* process an input envelope */

  	in_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
  	if (!in_env)
  		return -ENOMEM;

  	for (i = 0; i < desc->in_num; i++) {
  		u32 in_size, copy;
  
  		in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
  		if (in_size == UINT_MAX) {
  			dev_err(dev, "%s:%s unknown input size cmd: %s field: %d
  ",
  					__func__, dimm_name, cmd_name, i);

  			rc = -ENXIO;
  			goto out;

  		}

  		if (in_len < ND_CMD_MAX_ENVELOPE)
  			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - in_len, in_size);

  		else
  			copy = 0;

  		if (copy && copy_from_user(&in_env[in_len], p + in_len, copy)) {
  			rc = -EFAULT;
  			goto out;
  		}

  		in_len += in_size;
  	}

  	if (cmd == ND_CMD_CALL) {

  		func = pkg.nd_command;

  		dev_dbg(dev, "%s, idx: %llu, in: %u, out: %u, len %llu
  ",
  				dimm_name, pkg.nd_command,

  				in_len, out_len, buf_len);

  	}

  	/* process an output envelope */

  	out_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
  	if (!out_env) {
  		rc = -ENOMEM;
  		goto out;
  	}

  	for (i = 0; i < desc->out_num; i++) {
  		u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,

  				(u32 *) in_env, (u32 *) out_env, 0);

  		u32 copy;
  
  		if (out_size == UINT_MAX) {

  			dev_dbg(dev, "%s unknown output size cmd: %s field: %d
  ",
  					dimm_name, cmd_name, i);

  			rc = -EFAULT;
  			goto out;

  		}

  		if (out_len < ND_CMD_MAX_ENVELOPE)
  			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - out_len, out_size);

  		else
  			copy = 0;
  		if (copy && copy_from_user(&out_env[out_len],

  					p + in_len + out_len, copy)) {
  			rc = -EFAULT;
  			goto out;
  		}

  		out_len += out_size;
  	}

  	buf_len = (u64) out_len + (u64) in_len;

  	if (buf_len > ND_IOCTL_MAX_BUFLEN) {

  		dev_dbg(dev, "%s cmd: %s buf_len: %llu > %d
  ", dimm_name,
  				cmd_name, buf_len, ND_IOCTL_MAX_BUFLEN);

  		rc = -EINVAL;
  		goto out;

  	}
  
  	buf = vmalloc(buf_len);

  	if (!buf) {
  		rc = -ENOMEM;
  		goto out;
  	}

  
  	if (copy_from_user(buf, p, buf_len)) {
  		rc = -EFAULT;
  		goto out;
  	}

  	nd_device_lock(dev);

  	nvdimm_bus_lock(dev);

  	rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, func, buf);

  	if (rc)
  		goto out_unlock;

  	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, &cmd_rc);

  	if (rc < 0)

  		goto out_unlock;

  
  	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR && cmd_rc >= 0) {
  		struct nd_cmd_clear_error *clear_err = buf;

  		nvdimm_account_cleared_poison(nvdimm_bus, clear_err->address,
  				clear_err->cleared);

  	}

  	if (copy_to_user(p, buf, buf_len))
  		rc = -EFAULT;

  out_unlock:

  	nvdimm_bus_unlock(dev);

  	nd_device_unlock(dev);

  out:
  	kfree(in_env);
  	kfree(out_env);

  	vfree(buf);
  	return rc;
  }

  enum nd_ioctl_mode {
  	BUS_IOCTL,
  	DIMM_IOCTL,
  };

  
  static int match_dimm(struct device *dev, void *data)
  {
  	long id = (long) data;
  
  	if (is_nvdimm(dev)) {
  		struct nvdimm *nvdimm = to_nvdimm(dev);
  
  		return nvdimm->id == id;
  	}
  
  	return 0;
  }

  static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
  		enum nd_ioctl_mode mode)

  {

  	struct nvdimm_bus *nvdimm_bus, *found = NULL;
  	long id = (long) file->private_data;
  	struct nvdimm *nvdimm = NULL;
  	int rc, ro;

  	ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);

  	mutex_lock(&nvdimm_bus_list_mutex);
  	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {

  		if (mode == DIMM_IOCTL) {
  			struct device *dev;
  
  			dev = device_find_child(&nvdimm_bus->dev,
  					file->private_data, match_dimm);
  			if (!dev)
  				continue;
  			nvdimm = to_nvdimm(dev);
  			found = nvdimm_bus;
  		} else if (nvdimm_bus->id == id) {
  			found = nvdimm_bus;
  		}

  		if (found) {
  			atomic_inc(&nvdimm_bus->ioctl_active);
  			break;
  		}

  	}
  	mutex_unlock(&nvdimm_bus_list_mutex);

  	if (!found)
  		return -ENXIO;
  
  	nvdimm_bus = found;
  	rc = __nd_ioctl(nvdimm_bus, nvdimm, ro, cmd, arg);
  
  	if (nvdimm)
  		put_device(&nvdimm->dev);
  	if (atomic_dec_and_test(&nvdimm_bus->ioctl_active))
  		wake_up(&nvdimm_bus->wait);

  	return rc;
  }

  static long bus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  {
  	return nd_ioctl(file, cmd, arg, BUS_IOCTL);
  }
  
  static long dimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  {
  	return nd_ioctl(file, cmd, arg, DIMM_IOCTL);
  }

  static int nd_open(struct inode *inode, struct file *file)
  {
  	long minor = iminor(inode);
  
  	file->private_data = (void *) minor;
  	return 0;

  }
  
  static const struct file_operations nvdimm_bus_fops = {
  	.owner = THIS_MODULE,

  	.open = nd_open,

  	.unlocked_ioctl = bus_ioctl,
  	.compat_ioctl = bus_ioctl,

  	.llseek = noop_llseek,
  };

  static const struct file_operations nvdimm_fops = {
  	.owner = THIS_MODULE,
  	.open = nd_open,

  	.unlocked_ioctl = dimm_ioctl,
  	.compat_ioctl = dimm_ioctl,

  	.llseek = noop_llseek,
  };

  int __init nvdimm_bus_init(void)
  {
  	int rc;

  	rc = bus_register(&nvdimm_bus_type);
  	if (rc)
  		return rc;

  	rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
  	if (rc < 0)

  		goto err_bus_chrdev;

  	nvdimm_bus_major = rc;

  	rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
  	if (rc < 0)
  		goto err_dimm_chrdev;
  	nvdimm_major = rc;

  	nd_class = class_create(THIS_MODULE, "nd");

  	if (IS_ERR(nd_class)) {
  		rc = PTR_ERR(nd_class);

  		goto err_class;

  	}

  	rc = driver_register(&nd_bus_driver.drv);
  	if (rc)
  		goto err_nd_bus;

  	return 0;

   err_nd_bus:
  	class_destroy(nd_class);

   err_class:

  	unregister_chrdev(nvdimm_major, "dimmctl");
   err_dimm_chrdev:

  	unregister_chrdev(nvdimm_bus_major, "ndctl");

   err_bus_chrdev:

  	bus_unregister(&nvdimm_bus_type);

  
  	return rc;
  }

  void nvdimm_bus_exit(void)

  {

  	driver_unregister(&nd_bus_driver.drv);

  	class_destroy(nd_class);
  	unregister_chrdev(nvdimm_bus_major, "ndctl");

  	unregister_chrdev(nvdimm_major, "dimmctl");

  	bus_unregister(&nvdimm_bus_type);

  	ida_destroy(&nd_ida);

  }