drivers/nvdimm/core.c - kernel/bruno - Git at Google

 /*
  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
  * published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  */
 #include <linux/libnvdimm.h>
 #include <linux/export.h>
 #include <linux/module.h>
 #include <linux/blkdev.h>
 #include <linux/device.h>
 #include <linux/ctype.h>
 #include <linux/ndctl.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include "nd-core.h"
 #include "nd.h"

 LIST_HEAD(nvdimm_bus_list);
 DEFINE_MUTEX(nvdimm_bus_list_mutex);
 static DEFINE_IDA(nd_ida);

 void nvdimm_bus_lock(struct device *dev)
 {
 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);

 	if (!nvdimm_bus)
 		return;
 	mutex_lock(&nvdimm_bus->reconfig_mutex);
 }
 EXPORT_SYMBOL(nvdimm_bus_lock);

 void nvdimm_bus_unlock(struct device *dev)
 {
 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);

 	if (!nvdimm_bus)
 		return;
 	mutex_unlock(&nvdimm_bus->reconfig_mutex);
 }
 EXPORT_SYMBOL(nvdimm_bus_unlock);

 bool is_nvdimm_bus_locked(struct device *dev)
 {
 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);

 	if (!nvdimm_bus)
 		return false;
 	return mutex_is_locked(&nvdimm_bus->reconfig_mutex);
 }
 EXPORT_SYMBOL(is_nvdimm_bus_locked);

 u64 nd_fletcher64(void *addr, size_t len, bool le)
 {
 	u32 *buf = addr;
 	u32 lo32 = 0;
 	u64 hi32 = 0;
 	int i;

 	for (i = 0; i < len / sizeof(u32); i++) {
 		lo32 += le ? le32_to_cpu((__le32) buf[i]) : buf[i];
 		hi32 += lo32;
 	}

 	return hi32 << 32 | lo32;
 }
 EXPORT_SYMBOL_GPL(nd_fletcher64);

 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);
 }

 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(nvdimm_bus->dev.release != nvdimm_bus_release);
 	return nvdimm_bus;
 }
 EXPORT_SYMBOL_GPL(to_nvdimm_bus);

 struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus)
 {
 	/* struct nvdimm_bus definition is private to libnvdimm */
 	return nvdimm_bus->nd_desc;
 }
 EXPORT_SYMBOL_GPL(to_nd_desc);

 struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
 {
 	struct device *dev;

 	for (dev = nd_dev; dev; dev = dev->parent)
 		if (dev->release == nvdimm_bus_release)
 			break;
 	dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
 	if (dev)
 		return to_nvdimm_bus(dev);
 	return NULL;
 }

 static bool is_uuid_sep(char sep)
 {
 	if (sep == '\n' || sep == '-' || sep == ':' || sep == '\0')
 		return true;
 	return false;
 }

 static int nd_uuid_parse(struct device *dev, u8 *uuid_out, const char *buf,
 		size_t len)
 {
 	const char *str = buf;
 	u8 uuid[16];
 	int i;

 	for (i = 0; i < 16; i++) {
 		if (!isxdigit(str[0]) || !isxdigit(str[1])) {
 			dev_dbg(dev, "%s: pos: %d buf[%zd]: %c buf[%zd]: %c\n",
 					__func__, i, str - buf, str[0],
 					str + 1 - buf, str[1]);
 			return -EINVAL;
 		}

 		uuid[i] = (hex_to_bin(str[0]) << 4) | hex_to_bin(str[1]);
 		str += 2;
 		if (is_uuid_sep(*str))
 			str++;
 	}

 	memcpy(uuid_out, uuid, sizeof(uuid));
 	return 0;
 }

 /**
  * nd_uuid_store: common implementation for writing 'uuid' sysfs attributes
  * @dev: container device for the uuid property
  * @uuid_out: uuid buffer to replace
  * @buf: raw sysfs buffer to parse
  *
  * Enforce that uuids can only be changed while the device is disabled
  * (driver detached)
  * LOCKING: expects device_lock() is held on entry
  */
 int nd_uuid_store(struct device *dev, u8 **uuid_out, const char *buf,
 		size_t len)
 {
 	u8 uuid[16];
 	int rc;

 	if (dev->driver)
 		return -EBUSY;

 	rc = nd_uuid_parse(dev, uuid, buf, len);
 	if (rc)
 		return rc;

 	kfree(*uuid_out);
 	*uuid_out = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
 	if (!(*uuid_out))
 		return -ENOMEM;

 	return 0;
 }

 ssize_t nd_sector_size_show(unsigned long current_lbasize,
 		const unsigned long *supported, char *buf)
 {
 	ssize_t len = 0;
 	int i;

 	for (i = 0; supported[i]; i++)
 		if (current_lbasize == supported[i])
 			len += sprintf(buf + len, "[%ld] ", supported[i]);
 		else
 			len += sprintf(buf + len, "%ld ", supported[i]);
 	len += sprintf(buf + len, "\n");
 	return len;
 }

 ssize_t nd_sector_size_store(struct device *dev, const char *buf,
 		unsigned long *current_lbasize, const unsigned long *supported)
 {
 	unsigned long lbasize;
 	int rc, i;

 	if (dev->driver)
 		return -EBUSY;

 	rc = kstrtoul(buf, 0, &lbasize);
 	if (rc)
 		return rc;

 	for (i = 0; supported[i]; i++)
 		if (lbasize == supported[i])
 			break;

 	if (supported[i]) {
 		*current_lbasize = lbasize;
 		return 0;
 	} else {
 		return -EINVAL;
 	}
 }

 void __nd_iostat_start(struct bio *bio, unsigned long *start)
 {
 	struct gendisk *disk = bio->bi_bdev->bd_disk;
 	const int rw = bio_data_dir(bio);
 	int cpu = part_stat_lock();

 	*start = jiffies;
 	part_round_stats(cpu, &disk->part0);
 	part_stat_inc(cpu, &disk->part0, ios[rw]);
 	part_stat_add(cpu, &disk->part0, sectors[rw], bio_sectors(bio));
 	part_inc_in_flight(&disk->part0, rw);
 	part_stat_unlock();
 }
 EXPORT_SYMBOL(__nd_iostat_start);

 void nd_iostat_end(struct bio *bio, unsigned long start)
 {
 	struct gendisk *disk = bio->bi_bdev->bd_disk;
 	unsigned long duration = jiffies - start;
 	const int rw = bio_data_dir(bio);
 	int cpu = part_stat_lock();

 	part_stat_add(cpu, &disk->part0, ticks[rw], duration);
 	part_round_stats(cpu, &disk->part0);
 	part_dec_in_flight(&disk->part0, rw);
 	part_stat_unlock();
 }
 EXPORT_SYMBOL(nd_iostat_end);

 static ssize_t commands_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	int cmd, len = 0;
 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;

 	for_each_set_bit(cmd, &nd_desc->dsm_mask, BITS_PER_LONG)
 		len += sprintf(buf + len, "%s ", nvdimm_bus_cmd_name(cmd));
 	len += sprintf(buf + len, "\n");
 	return len;
 }
 static DEVICE_ATTR_RO(commands);

 static const char *nvdimm_bus_provider(struct nvdimm_bus *nvdimm_bus)
 {
 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 	struct device *parent = nvdimm_bus->dev.parent;

 	if (nd_desc->provider_name)
 		return nd_desc->provider_name;
 	else if (parent)
 		return dev_name(parent);
 	else
 		return "unknown";
 }

 static ssize_t provider_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);

 	return sprintf(buf, "%s\n", nvdimm_bus_provider(nvdimm_bus));
 }
 static DEVICE_ATTR_RO(provider);

 static int flush_namespaces(struct device *dev, void *data)
 {
 	device_lock(dev);
 	device_unlock(dev);
 	return 0;
 }

 static int flush_regions_dimms(struct device *dev, void *data)
 {
 	device_lock(dev);
 	device_unlock(dev);
 	device_for_each_child(dev, NULL, flush_namespaces);
 	return 0;
 }

 static ssize_t wait_probe_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	nd_synchronize();
 	device_for_each_child(dev, NULL, flush_regions_dimms);
 	return sprintf(buf, "1\n");
 }
 static DEVICE_ATTR_RO(wait_probe);

 static struct attribute *nvdimm_bus_attributes[] = {
 	&dev_attr_commands.attr,
 	&dev_attr_wait_probe.attr,
 	&dev_attr_provider.attr,
 	NULL,
 };

 struct attribute_group nvdimm_bus_attribute_group = {
 	.attrs = nvdimm_bus_attributes,
 };
 EXPORT_SYMBOL_GPL(nvdimm_bus_attribute_group);

 struct nvdimm_bus *__nvdimm_bus_register(struct device *parent,
 		struct nvdimm_bus_descriptor *nd_desc, struct module *module)
 {
 	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_waitqueue_head(&nvdimm_bus->probe_wait);
 	nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
 	mutex_init(&nvdimm_bus->reconfig_mutex);
 	if (nvdimm_bus->id < 0) {
 		kfree(nvdimm_bus);
 		return NULL;
 	}
 	nvdimm_bus->nd_desc = nd_desc;
 	nvdimm_bus->module = module;
 	nvdimm_bus->dev.parent = parent;
 	nvdimm_bus->dev.release = nvdimm_bus_release;
 	nvdimm_bus->dev.groups = nd_desc->attr_groups;
 	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\n", rc);
 		goto err;
 	}

 	rc = nvdimm_bus_create_ndctl(nvdimm_bus);
 	if (rc)
 		goto err;

 	mutex_lock(&nvdimm_bus_list_mutex);
 	list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
 	mutex_unlock(&nvdimm_bus_list_mutex);

 	return nvdimm_bus;
  err:
 	put_device(&nvdimm_bus->dev);
 	return NULL;
 }
 EXPORT_SYMBOL_GPL(__nvdimm_bus_register);

 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)
 		/* pass */;
 	else
 		nd_device_unregister(dev, ND_SYNC);
 	return 0;
 }

 void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
 {
 	if (!nvdimm_bus)
 		return;

 	mutex_lock(&nvdimm_bus_list_mutex);
 	list_del_init(&nvdimm_bus->list);
 	mutex_unlock(&nvdimm_bus_list_mutex);

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

 	device_unregister(&nvdimm_bus->dev);
 }
 EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);

 #ifdef CONFIG_BLK_DEV_INTEGRITY
 int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
 {
 	struct blk_integrity bi;

 	if (meta_size == 0)
 		return 0;

 	bi.profile = NULL;
 	bi.tuple_size = meta_size;
 	bi.tag_size = meta_size;

 	blk_integrity_register(disk, &bi);
 	blk_queue_max_integrity_segments(disk->queue, 1);

 	return 0;
 }
 EXPORT_SYMBOL(nd_integrity_init);

 #else /* CONFIG_BLK_DEV_INTEGRITY */
 int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
 {
 	return 0;
 }
 EXPORT_SYMBOL(nd_integrity_init);

 #endif

 static __init int libnvdimm_init(void)
 {
 	int rc;

 	rc = nvdimm_bus_init();
 	if (rc)
 		return rc;
 	rc = nvdimm_init();
 	if (rc)
 		goto err_dimm;
 	rc = nd_region_init();
 	if (rc)
 		goto err_region;
 	return 0;
  err_region:
 	nvdimm_exit();
  err_dimm:
 	nvdimm_bus_exit();
 	return rc;
 }

 static __exit void libnvdimm_exit(void)
 {
 	WARN_ON(!list_empty(&nvdimm_bus_list));
 	nd_region_exit();
 	nvdimm_exit();
 	nvdimm_bus_exit();
 }

 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Intel Corporation");
 subsys_initcall(libnvdimm_init);
 module_exit(libnvdimm_exit);
	/*
	* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of version 2 of the GNU General Public License as
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*/
	#include <linux/libnvdimm.h>
	#include <linux/export.h>
	#include <linux/module.h>
	#include <linux/blkdev.h>
	#include <linux/device.h>
	#include <linux/ctype.h>
	#include <linux/ndctl.h>
	#include <linux/mutex.h>
	#include <linux/slab.h>
	#include "nd-core.h"
	#include "nd.h"

	LIST_HEAD(nvdimm_bus_list);
	DEFINE_MUTEX(nvdimm_bus_list_mutex);
	static DEFINE_IDA(nd_ida);

	void nvdimm_bus_lock(struct device *dev)
	{
	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);

	if (!nvdimm_bus)
	return;
	mutex_lock(&nvdimm_bus->reconfig_mutex);
	}
	EXPORT_SYMBOL(nvdimm_bus_lock);

	void nvdimm_bus_unlock(struct device *dev)
	{
	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);

	if (!nvdimm_bus)
	return;
	mutex_unlock(&nvdimm_bus->reconfig_mutex);
	}
	EXPORT_SYMBOL(nvdimm_bus_unlock);

	bool is_nvdimm_bus_locked(struct device *dev)
	{
	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);

	if (!nvdimm_bus)
	return false;
	return mutex_is_locked(&nvdimm_bus->reconfig_mutex);
	}
	EXPORT_SYMBOL(is_nvdimm_bus_locked);

	u64 nd_fletcher64(void *addr, size_t len, bool le)
	{
	u32 *buf = addr;
	u32 lo32 = 0;
	u64 hi32 = 0;
	int i;

	for (i = 0; i < len / sizeof(u32); i++) {
	lo32 += le ? le32_to_cpu((__le32) buf[i]) : buf[i];
	hi32 += lo32;
	}

	return hi32 << 32 \| lo32;
	}
	EXPORT_SYMBOL_GPL(nd_fletcher64);

	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);
	}

	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(nvdimm_bus->dev.release != nvdimm_bus_release);
	return nvdimm_bus;
	}
	EXPORT_SYMBOL_GPL(to_nvdimm_bus);

	struct nvdimm_bus_descriptor to_nd_desc(struct nvdimm_bus nvdimm_bus)
	{
	/* struct nvdimm_bus definition is private to libnvdimm */
	return nvdimm_bus->nd_desc;
	}
	EXPORT_SYMBOL_GPL(to_nd_desc);

	struct nvdimm_bus walk_to_nvdimm_bus(struct device nd_dev)
	{
	struct device *dev;

	for (dev = nd_dev; dev; dev = dev->parent)
	if (dev->release == nvdimm_bus_release)
	break;
	dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
	if (dev)
	return to_nvdimm_bus(dev);
	return NULL;
	}

	static bool is_uuid_sep(char sep)
	{
	if (sep == '\n' \|\| sep == '-' \|\| sep == ':' \|\| sep == '\0')
	return true;
	return false;
	}

	static int nd_uuid_parse(struct device dev, u8 uuid_out, const char *buf,
	size_t len)
	{
	const char *str = buf;
	u8 uuid[16];
	int i;

	for (i = 0; i < 16; i++) {
	if (!isxdigit(str[0]) \|\| !isxdigit(str[1])) {
	dev_dbg(dev, "%s: pos: %d buf[%zd]: %c buf[%zd]: %c\n",
	__func__, i, str - buf, str[0],
	str + 1 - buf, str[1]);
	return -EINVAL;
	}

	uuid[i] = (hex_to_bin(str[0]) << 4) \| hex_to_bin(str[1]);
	str += 2;
	if (is_uuid_sep(*str))
	str++;
	}

	memcpy(uuid_out, uuid, sizeof(uuid));
	return 0;
	}

	/**
	* nd_uuid_store: common implementation for writing 'uuid' sysfs attributes
	* @dev: container device for the uuid property
	* @uuid_out: uuid buffer to replace
	* @buf: raw sysfs buffer to parse
	*
	* Enforce that uuids can only be changed while the device is disabled
	* (driver detached)
	* LOCKING: expects device_lock() is held on entry
	*/
	int nd_uuid_store(struct device dev, u8 uuid_out, const char buf,
	size_t len)
	{
	u8 uuid[16];
	int rc;

	if (dev->driver)
	return -EBUSY;

	rc = nd_uuid_parse(dev, uuid, buf, len);
	if (rc)
	return rc;

	kfree(*uuid_out);
	*uuid_out = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
	if (!(*uuid_out))
	return -ENOMEM;

	return 0;
	}

	ssize_t nd_sector_size_show(unsigned long current_lbasize,
	const unsigned long supported, char buf)
	{
	ssize_t len = 0;
	int i;

	for (i = 0; supported[i]; i++)
	if (current_lbasize == supported[i])
	len += sprintf(buf + len, "[%ld] ", supported[i]);
	else
	len += sprintf(buf + len, "%ld ", supported[i]);
	len += sprintf(buf + len, "\n");
	return len;
	}

	ssize_t nd_sector_size_store(struct device dev, const char buf,
	unsigned long current_lbasize, const unsigned long supported)
	{
	unsigned long lbasize;
	int rc, i;

	if (dev->driver)
	return -EBUSY;

	rc = kstrtoul(buf, 0, &lbasize);
	if (rc)
	return rc;

	for (i = 0; supported[i]; i++)
	if (lbasize == supported[i])
	break;

	if (supported[i]) {
	*current_lbasize = lbasize;
	return 0;
	} else {
	return -EINVAL;
	}
	}

	void __nd_iostat_start(struct bio bio, unsigned long start)
	{
	struct gendisk *disk = bio->bi_bdev->bd_disk;
	const int rw = bio_data_dir(bio);
	int cpu = part_stat_lock();

	*start = jiffies;
	part_round_stats(cpu, &disk->part0);
	part_stat_inc(cpu, &disk->part0, ios[rw]);
	part_stat_add(cpu, &disk->part0, sectors[rw], bio_sectors(bio));
	part_inc_in_flight(&disk->part0, rw);
	part_stat_unlock();
	}
	EXPORT_SYMBOL(__nd_iostat_start);

	void nd_iostat_end(struct bio *bio, unsigned long start)
	{
	struct gendisk *disk = bio->bi_bdev->bd_disk;
	unsigned long duration = jiffies - start;
	const int rw = bio_data_dir(bio);
	int cpu = part_stat_lock();

	part_stat_add(cpu, &disk->part0, ticks[rw], duration);
	part_round_stats(cpu, &disk->part0);
	part_dec_in_flight(&disk->part0, rw);
	part_stat_unlock();
	}
	EXPORT_SYMBOL(nd_iostat_end);

	static ssize_t commands_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	int cmd, len = 0;
	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;

	for_each_set_bit(cmd, &nd_desc->dsm_mask, BITS_PER_LONG)
	len += sprintf(buf + len, "%s ", nvdimm_bus_cmd_name(cmd));
	len += sprintf(buf + len, "\n");
	return len;
	}
	static DEVICE_ATTR_RO(commands);

	static const char nvdimm_bus_provider(struct nvdimm_bus nvdimm_bus)
	{
	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
	struct device *parent = nvdimm_bus->dev.parent;

	if (nd_desc->provider_name)
	return nd_desc->provider_name;
	else if (parent)
	return dev_name(parent);
	else
	return "unknown";
	}

	static ssize_t provider_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);

	return sprintf(buf, "%s\n", nvdimm_bus_provider(nvdimm_bus));
	}
	static DEVICE_ATTR_RO(provider);

	static int flush_namespaces(struct device dev, void data)
	{
	device_lock(dev);
	device_unlock(dev);
	return 0;
	}

	static int flush_regions_dimms(struct device dev, void data)
	{
	device_lock(dev);
	device_unlock(dev);
	device_for_each_child(dev, NULL, flush_namespaces);
	return 0;
	}

	static ssize_t wait_probe_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	nd_synchronize();
	device_for_each_child(dev, NULL, flush_regions_dimms);
	return sprintf(buf, "1\n");
	}
	static DEVICE_ATTR_RO(wait_probe);

	static struct attribute *nvdimm_bus_attributes[] = {
	&dev_attr_commands.attr,
	&dev_attr_wait_probe.attr,
	&dev_attr_provider.attr,
	NULL,
	};

	struct attribute_group nvdimm_bus_attribute_group = {
	.attrs = nvdimm_bus_attributes,
	};
	EXPORT_SYMBOL_GPL(nvdimm_bus_attribute_group);

	struct nvdimm_bus __nvdimm_bus_register(struct device parent,
	struct nvdimm_bus_descriptor nd_desc, struct module module)
	{
	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_waitqueue_head(&nvdimm_bus->probe_wait);
	nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
	mutex_init(&nvdimm_bus->reconfig_mutex);
	if (nvdimm_bus->id < 0) {
	kfree(nvdimm_bus);
	return NULL;
	}
	nvdimm_bus->nd_desc = nd_desc;
	nvdimm_bus->module = module;
	nvdimm_bus->dev.parent = parent;
	nvdimm_bus->dev.release = nvdimm_bus_release;
	nvdimm_bus->dev.groups = nd_desc->attr_groups;
	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\n", rc);
	goto err;
	}

	rc = nvdimm_bus_create_ndctl(nvdimm_bus);
	if (rc)
	goto err;

	mutex_lock(&nvdimm_bus_list_mutex);
	list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
	mutex_unlock(&nvdimm_bus_list_mutex);

	return nvdimm_bus;
	err:
	put_device(&nvdimm_bus->dev);
	return NULL;
	}
	EXPORT_SYMBOL_GPL(__nvdimm_bus_register);

	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)
	/* pass */;
	else
	nd_device_unregister(dev, ND_SYNC);
	return 0;
	}

	void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
	{
	if (!nvdimm_bus)
	return;

	mutex_lock(&nvdimm_bus_list_mutex);
	list_del_init(&nvdimm_bus->list);
	mutex_unlock(&nvdimm_bus_list_mutex);

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

	device_unregister(&nvdimm_bus->dev);
	}
	EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);

	#ifdef CONFIG_BLK_DEV_INTEGRITY
	int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
	{
	struct blk_integrity bi;

	if (meta_size == 0)
	return 0;

	bi.profile = NULL;
	bi.tuple_size = meta_size;
	bi.tag_size = meta_size;

	blk_integrity_register(disk, &bi);
	blk_queue_max_integrity_segments(disk->queue, 1);

	return 0;
	}
	EXPORT_SYMBOL(nd_integrity_init);

	#else /* CONFIG_BLK_DEV_INTEGRITY */
	int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
	{
	return 0;
	}
	EXPORT_SYMBOL(nd_integrity_init);

	#endif

	static __init int libnvdimm_init(void)
	{
	int rc;

	rc = nvdimm_bus_init();
	if (rc)
	return rc;
	rc = nvdimm_init();
	if (rc)
	goto err_dimm;
	rc = nd_region_init();
	if (rc)
	goto err_region;
	return 0;
	err_region:
	nvdimm_exit();
	err_dimm:
	nvdimm_bus_exit();
	return rc;
	}

	static __exit void libnvdimm_exit(void)
	{
	WARN_ON(!list_empty(&nvdimm_bus_list));
	nd_region_exit();
	nvdimm_exit();
	nvdimm_bus_exit();
	}

	MODULE_LICENSE("GPL v2");
	MODULE_AUTHOR("Intel Corporation");
	subsys_initcall(libnvdimm_init);
	module_exit(libnvdimm_exit);