drivers/nvdimm/core.c - kernel/msm-4.19 - Gitiles

 /*
  * 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/badblocks.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 <linux/io.h>
 #include "nd-core.h"
 #include "nd.h"

 LIST_HEAD(nvdimm_bus_list);
 DEFINE_MUTEX(nvdimm_bus_list_mutex);

 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);

 struct nvdimm_map {
 	struct nvdimm_bus *nvdimm_bus;
 	struct list_head list;
 	resource_size_t offset;
 	unsigned long flags;
 	size_t size;
 	union {
 		void *mem;
 		void __iomem *iomem;
 	};
 	struct kref kref;
 };

 static struct nvdimm_map *find_nvdimm_map(struct device *dev,
 		resource_size_t offset)
 {
 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 	struct nvdimm_map *nvdimm_map;

 	list_for_each_entry(nvdimm_map, &nvdimm_bus->mapping_list, list)
 		if (nvdimm_map->offset == offset)
 			return nvdimm_map;
 	return NULL;
 }

 static struct nvdimm_map *alloc_nvdimm_map(struct device *dev,
 		resource_size_t offset, size_t size, unsigned long flags)
 {
 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 	struct nvdimm_map *nvdimm_map;

 	nvdimm_map = kzalloc(sizeof(*nvdimm_map), GFP_KERNEL);
 	if (!nvdimm_map)
 		return NULL;

 	INIT_LIST_HEAD(&nvdimm_map->list);
 	nvdimm_map->nvdimm_bus = nvdimm_bus;
 	nvdimm_map->offset = offset;
 	nvdimm_map->flags = flags;
 	nvdimm_map->size = size;
 	kref_init(&nvdimm_map->kref);

 	if (!request_mem_region(offset, size, dev_name(&nvdimm_bus->dev)))
 		goto err_request_region;

 	if (flags)
 		nvdimm_map->mem = memremap(offset, size, flags);
 	else
 		nvdimm_map->iomem = ioremap(offset, size);

 	if (!nvdimm_map->mem)
 		goto err_map;

 	dev_WARN_ONCE(dev, !is_nvdimm_bus_locked(dev), "%s: bus unlocked!",
 			__func__);
 	list_add(&nvdimm_map->list, &nvdimm_bus->mapping_list);

 	return nvdimm_map;

  err_map:
 	release_mem_region(offset, size);
  err_request_region:
 	kfree(nvdimm_map);
 	return NULL;
 }

 static void nvdimm_map_release(struct kref *kref)
 {
 	struct nvdimm_bus *nvdimm_bus;
 	struct nvdimm_map *nvdimm_map;

 	nvdimm_map = container_of(kref, struct nvdimm_map, kref);
 	nvdimm_bus = nvdimm_map->nvdimm_bus;

 	dev_dbg(&nvdimm_bus->dev, "%s: %pa\n", __func__, &nvdimm_map->offset);
 	list_del(&nvdimm_map->list);
 	if (nvdimm_map->flags)
 		memunmap(nvdimm_map->mem);
 	else
 		iounmap(nvdimm_map->iomem);
 	release_mem_region(nvdimm_map->offset, nvdimm_map->size);
 	kfree(nvdimm_map);
 }

 static void nvdimm_map_put(void *data)
 {
 	struct nvdimm_map *nvdimm_map = data;
 	struct nvdimm_bus *nvdimm_bus = nvdimm_map->nvdimm_bus;

 	nvdimm_bus_lock(&nvdimm_bus->dev);
 	kref_put(&nvdimm_map->kref, nvdimm_map_release);
 	nvdimm_bus_unlock(&nvdimm_bus->dev);
 }

 /**
  * devm_nvdimm_memremap - map a resource that is shared across regions
  * @dev: device that will own a reference to the shared mapping
  * @offset: physical base address of the mapping
  * @size: mapping size
  * @flags: memremap flags, or, if zero, perform an ioremap instead
  */
 void *devm_nvdimm_memremap(struct device *dev, resource_size_t offset,
 		size_t size, unsigned long flags)
 {
 	struct nvdimm_map *nvdimm_map;

 	nvdimm_bus_lock(dev);
 	nvdimm_map = find_nvdimm_map(dev, offset);
 	if (!nvdimm_map)
 		nvdimm_map = alloc_nvdimm_map(dev, offset, size, flags);
 	else
 		kref_get(&nvdimm_map->kref);
 	nvdimm_bus_unlock(dev);

 	if (devm_add_action_or_reset(dev, nvdimm_map_put, nvdimm_map))
 		return NULL;

 	return nvdimm_map->mem;
 }
 EXPORT_SYMBOL_GPL(devm_nvdimm_memremap);

 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);

 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);

 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->cmd_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)
 {
 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 	int rc;

 	if (nd_desc->flush_probe) {
 		rc = nd_desc->flush_probe(nd_desc);
 		if (rc)
 			return rc;
 	}
 	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);

 static void set_badblock(struct badblocks *bb, sector_t s, int num)
 {
 	dev_dbg(bb->dev, "Found a poison range (0x%llx, 0x%llx)\n",
 			(u64) s * 512, (u64) num * 512);
 	/* this isn't an error as the hardware will still throw an exception */
 	if (badblocks_set(bb, s, num, 1))
 		dev_info_once(bb->dev, "%s: failed for sector %llx\n",
 				__func__, (u64) s);
 }

 /**
  * __add_badblock_range() - Convert a physical address range to bad sectors
  * @bb:		badblocks instance to populate
  * @ns_offset:	namespace offset where the error range begins (in bytes)
  * @len:	number of bytes of poison to be added
  *
  * This assumes that the range provided with (ns_offset, len) is within
  * the bounds of physical addresses for this namespace, i.e. lies in the
  * interval [ns_start, ns_start + ns_size)
  */
 static void __add_badblock_range(struct badblocks *bb, u64 ns_offset, u64 len)
 {
 	const unsigned int sector_size = 512;
 	sector_t start_sector;
 	u64 num_sectors;
 	u32 rem;

 	start_sector = div_u64(ns_offset, sector_size);
 	num_sectors = div_u64_rem(len, sector_size, &rem);
 	if (rem)
 		num_sectors++;

 	if (unlikely(num_sectors > (u64)INT_MAX)) {
 		u64 remaining = num_sectors;
 		sector_t s = start_sector;

 		while (remaining) {
 			int done = min_t(u64, remaining, INT_MAX);

 			set_badblock(bb, s, done);
 			remaining -= done;
 			s += done;
 		}
 	} else
 		set_badblock(bb, start_sector, num_sectors);
 }

 static void badblocks_populate(struct list_head *poison_list,
 		struct badblocks *bb, const struct resource *res)
 {
 	struct nd_poison *pl;

 	if (list_empty(poison_list))
 		return;

 	list_for_each_entry(pl, poison_list, list) {
 		u64 pl_end = pl->start + pl->length - 1;

 		/* Discard intervals with no intersection */
 		if (pl_end < res->start)
 			continue;
 		if (pl->start >  res->end)
 			continue;
 		/* Deal with any overlap after start of the namespace */
 		if (pl->start >= res->start) {
 			u64 start = pl->start;
 			u64 len;

 			if (pl_end <= res->end)
 				len = pl->length;
 			else
 				len = res->start + resource_size(res)
 					- pl->start;
 			__add_badblock_range(bb, start - res->start, len);
 			continue;
 		}
 		/* Deal with overlap for poison starting before the namespace */
 		if (pl->start < res->start) {
 			u64 len;

 			if (pl_end < res->end)
 				len = pl->start + pl->length - res->start;
 			else
 				len = resource_size(res);
 			__add_badblock_range(bb, 0, len);
 		}
 	}
 }

 /**
  * nvdimm_badblocks_populate() - Convert a list of poison ranges to badblocks
  * @region: parent region of the range to interrogate
  * @bb: badblocks instance to populate
  * @res: resource range to consider
  *
  * The poison list generated during bus initialization may contain
  * multiple, possibly overlapping physical address ranges.  Compare each
  * of these ranges to the resource range currently being initialized,
  * and add badblocks entries for all matching sub-ranges
  */
 void nvdimm_badblocks_populate(struct nd_region *nd_region,
 		struct badblocks *bb, const struct resource *res)
 {
 	struct nvdimm_bus *nvdimm_bus;
 	struct list_head *poison_list;

 	if (!is_nd_pmem(&nd_region->dev)) {
 		dev_WARN_ONCE(&nd_region->dev, 1,
 				"%s only valid for pmem regions\n", __func__);
 		return;
 	}
 	nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
 	poison_list = &nvdimm_bus->poison_list;

 	nvdimm_bus_lock(&nvdimm_bus->dev);
 	badblocks_populate(poison_list, bb, res);
 	nvdimm_bus_unlock(&nvdimm_bus->dev);
 }
 EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate);

 static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
 {
 	struct nd_poison *pl;

 	pl = kzalloc(sizeof(*pl), GFP_KERNEL);
 	if (!pl)
 		return -ENOMEM;

 	pl->start = addr;
 	pl->length = length;
 	list_add_tail(&pl->list, &nvdimm_bus->poison_list);

 	return 0;
 }

 static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
 {
 	struct nd_poison *pl;

 	if (list_empty(&nvdimm_bus->poison_list))
 		return add_poison(nvdimm_bus, addr, length);

 	/*
 	 * There is a chance this is a duplicate, check for those first.
 	 * This will be the common case as ARS_STATUS returns all known
 	 * errors in the SPA space, and we can't query it per region
 	 */
 	list_for_each_entry(pl, &nvdimm_bus->poison_list, list)
 		if (pl->start == addr) {
 			/* If length has changed, update this list entry */
 			if (pl->length != length)
 				pl->length = length;
 			return 0;
 		}

 	/*
 	 * If not a duplicate or a simple length update, add the entry as is,
 	 * as any overlapping ranges will get resolved when the list is consumed
 	 * and converted to badblocks
 	 */
 	return add_poison(nvdimm_bus, addr, length);
 }

 int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
 {
 	int rc;

 	nvdimm_bus_lock(&nvdimm_bus->dev);
 	rc = bus_add_poison(nvdimm_bus, addr, length);
 	nvdimm_bus_unlock(&nvdimm_bus->dev);

 	return rc;
 }
 EXPORT_SYMBOL_GPL(nvdimm_bus_add_poison);

 #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;

 	memset(&bi, 0, sizeof(bi));

 	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();
 	nd_region_devs_exit();
 	nvdimm_devs_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/badblocks.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 <linux/io.h>
	#include "nd-core.h"
	#include "nd.h"

	LIST_HEAD(nvdimm_bus_list);
	DEFINE_MUTEX(nvdimm_bus_list_mutex);

	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);

	struct nvdimm_map {
	struct nvdimm_bus *nvdimm_bus;
	struct list_head list;
	resource_size_t offset;
	unsigned long flags;
	size_t size;
	union {
	void *mem;
	void __iomem *iomem;
	};
	struct kref kref;
	};

	static struct nvdimm_map find_nvdimm_map(struct device dev,
	resource_size_t offset)
	{
	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
	struct nvdimm_map *nvdimm_map;

	list_for_each_entry(nvdimm_map, &nvdimm_bus->mapping_list, list)
	if (nvdimm_map->offset == offset)
	return nvdimm_map;
	return NULL;
	}

	static struct nvdimm_map alloc_nvdimm_map(struct device dev,
	resource_size_t offset, size_t size, unsigned long flags)
	{
	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
	struct nvdimm_map *nvdimm_map;

	nvdimm_map = kzalloc(sizeof(*nvdimm_map), GFP_KERNEL);
	if (!nvdimm_map)
	return NULL;

	INIT_LIST_HEAD(&nvdimm_map->list);
	nvdimm_map->nvdimm_bus = nvdimm_bus;
	nvdimm_map->offset = offset;
	nvdimm_map->flags = flags;
	nvdimm_map->size = size;
	kref_init(&nvdimm_map->kref);

	if (!request_mem_region(offset, size, dev_name(&nvdimm_bus->dev)))
	goto err_request_region;

	if (flags)
	nvdimm_map->mem = memremap(offset, size, flags);
	else
	nvdimm_map->iomem = ioremap(offset, size);

	if (!nvdimm_map->mem)
	goto err_map;

	dev_WARN_ONCE(dev, !is_nvdimm_bus_locked(dev), "%s: bus unlocked!",
	__func__);
	list_add(&nvdimm_map->list, &nvdimm_bus->mapping_list);

	return nvdimm_map;

	err_map:
	release_mem_region(offset, size);
	err_request_region:
	kfree(nvdimm_map);
	return NULL;
	}

	static void nvdimm_map_release(struct kref *kref)
	{
	struct nvdimm_bus *nvdimm_bus;
	struct nvdimm_map *nvdimm_map;

	nvdimm_map = container_of(kref, struct nvdimm_map, kref);
	nvdimm_bus = nvdimm_map->nvdimm_bus;

	dev_dbg(&nvdimm_bus->dev, "%s: %pa\n", __func__, &nvdimm_map->offset);
	list_del(&nvdimm_map->list);
	if (nvdimm_map->flags)
	memunmap(nvdimm_map->mem);
	else
	iounmap(nvdimm_map->iomem);
	release_mem_region(nvdimm_map->offset, nvdimm_map->size);
	kfree(nvdimm_map);
	}

	static void nvdimm_map_put(void *data)
	{
	struct nvdimm_map *nvdimm_map = data;
	struct nvdimm_bus *nvdimm_bus = nvdimm_map->nvdimm_bus;

	nvdimm_bus_lock(&nvdimm_bus->dev);
	kref_put(&nvdimm_map->kref, nvdimm_map_release);
	nvdimm_bus_unlock(&nvdimm_bus->dev);
	}

	/**
	* devm_nvdimm_memremap - map a resource that is shared across regions
	* @dev: device that will own a reference to the shared mapping
	* @offset: physical base address of the mapping
	* @size: mapping size
	* @flags: memremap flags, or, if zero, perform an ioremap instead
	*/
	void devm_nvdimm_memremap(struct device dev, resource_size_t offset,
	size_t size, unsigned long flags)
	{
	struct nvdimm_map *nvdimm_map;

	nvdimm_bus_lock(dev);
	nvdimm_map = find_nvdimm_map(dev, offset);
	if (!nvdimm_map)
	nvdimm_map = alloc_nvdimm_map(dev, offset, size, flags);
	else
	kref_get(&nvdimm_map->kref);
	nvdimm_bus_unlock(dev);

	if (devm_add_action_or_reset(dev, nvdimm_map_put, nvdimm_map))
	return NULL;

	return nvdimm_map->mem;
	}
	EXPORT_SYMBOL_GPL(devm_nvdimm_memremap);

	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);

	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);

	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->cmd_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)
	{
	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
	int rc;

	if (nd_desc->flush_probe) {
	rc = nd_desc->flush_probe(nd_desc);
	if (rc)
	return rc;
	}
	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);

	static void set_badblock(struct badblocks *bb, sector_t s, int num)
	{
	dev_dbg(bb->dev, "Found a poison range (0x%llx, 0x%llx)\n",
	(u64) s * 512, (u64) num * 512);
	/* this isn't an error as the hardware will still throw an exception */
	if (badblocks_set(bb, s, num, 1))
	dev_info_once(bb->dev, "%s: failed for sector %llx\n",
	__func__, (u64) s);
	}

	/**
	* __add_badblock_range() - Convert a physical address range to bad sectors
	* @bb: badblocks instance to populate
	* @ns_offset: namespace offset where the error range begins (in bytes)
	* @len: number of bytes of poison to be added
	*
	* This assumes that the range provided with (ns_offset, len) is within
	* the bounds of physical addresses for this namespace, i.e. lies in the
	* interval [ns_start, ns_start + ns_size)
	*/
	static void __add_badblock_range(struct badblocks *bb, u64 ns_offset, u64 len)
	{
	const unsigned int sector_size = 512;
	sector_t start_sector;
	u64 num_sectors;
	u32 rem;

	start_sector = div_u64(ns_offset, sector_size);
	num_sectors = div_u64_rem(len, sector_size, &rem);
	if (rem)
	num_sectors++;

	if (unlikely(num_sectors > (u64)INT_MAX)) {
	u64 remaining = num_sectors;
	sector_t s = start_sector;

	while (remaining) {
	int done = min_t(u64, remaining, INT_MAX);

	set_badblock(bb, s, done);
	remaining -= done;
	s += done;
	}
	} else
	set_badblock(bb, start_sector, num_sectors);
	}

	static void badblocks_populate(struct list_head *poison_list,
	struct badblocks bb, const struct resource res)
	{
	struct nd_poison *pl;

	if (list_empty(poison_list))
	return;

	list_for_each_entry(pl, poison_list, list) {
	u64 pl_end = pl->start + pl->length - 1;

	/* Discard intervals with no intersection */
	if (pl_end < res->start)
	continue;
	if (pl->start > res->end)
	continue;
	/* Deal with any overlap after start of the namespace */
	if (pl->start >= res->start) {
	u64 start = pl->start;
	u64 len;

	if (pl_end <= res->end)
	len = pl->length;
	else
	len = res->start + resource_size(res)
	- pl->start;
	__add_badblock_range(bb, start - res->start, len);
	continue;
	}
	/* Deal with overlap for poison starting before the namespace */
	if (pl->start < res->start) {
	u64 len;

	if (pl_end < res->end)
	len = pl->start + pl->length - res->start;
	else
	len = resource_size(res);
	__add_badblock_range(bb, 0, len);
	}
	}
	}

	/**
	* nvdimm_badblocks_populate() - Convert a list of poison ranges to badblocks
	* @region: parent region of the range to interrogate
	* @bb: badblocks instance to populate
	* @res: resource range to consider
	*
	* The poison list generated during bus initialization may contain
	* multiple, possibly overlapping physical address ranges. Compare each
	* of these ranges to the resource range currently being initialized,
	* and add badblocks entries for all matching sub-ranges
	*/
	void nvdimm_badblocks_populate(struct nd_region *nd_region,
	struct badblocks bb, const struct resource res)
	{
	struct nvdimm_bus *nvdimm_bus;
	struct list_head *poison_list;

	if (!is_nd_pmem(&nd_region->dev)) {
	dev_WARN_ONCE(&nd_region->dev, 1,
	"%s only valid for pmem regions\n", __func__);
	return;
	}
	nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
	poison_list = &nvdimm_bus->poison_list;

	nvdimm_bus_lock(&nvdimm_bus->dev);
	badblocks_populate(poison_list, bb, res);
	nvdimm_bus_unlock(&nvdimm_bus->dev);
	}
	EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate);

	static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
	{
	struct nd_poison *pl;

	pl = kzalloc(sizeof(*pl), GFP_KERNEL);
	if (!pl)
	return -ENOMEM;

	pl->start = addr;
	pl->length = length;
	list_add_tail(&pl->list, &nvdimm_bus->poison_list);

	return 0;
	}

	static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
	{
	struct nd_poison *pl;

	if (list_empty(&nvdimm_bus->poison_list))
	return add_poison(nvdimm_bus, addr, length);

	/*
	* There is a chance this is a duplicate, check for those first.
	* This will be the common case as ARS_STATUS returns all known
	* errors in the SPA space, and we can't query it per region
	*/
	list_for_each_entry(pl, &nvdimm_bus->poison_list, list)
	if (pl->start == addr) {
	/* If length has changed, update this list entry */
	if (pl->length != length)
	pl->length = length;
	return 0;
	}

	/*
	* If not a duplicate or a simple length update, add the entry as is,
	* as any overlapping ranges will get resolved when the list is consumed
	* and converted to badblocks
	*/
	return add_poison(nvdimm_bus, addr, length);
	}

	int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
	{
	int rc;

	nvdimm_bus_lock(&nvdimm_bus->dev);
	rc = bus_add_poison(nvdimm_bus, addr, length);
	nvdimm_bus_unlock(&nvdimm_bus->dev);

	return rc;
	}
	EXPORT_SYMBOL_GPL(nvdimm_bus_add_poison);

	#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;

	memset(&bi, 0, sizeof(bi));

	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();
	nd_region_devs_exit();
	nvdimm_devs_exit();
	}

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