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

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

   */
  #include <linux/module.h>
  #include <linux/device.h>

  #include <linux/sort.h>

  #include <linux/slab.h>

  #include <linux/list.h>

  #include <linux/nd.h>

  #include "nd-core.h"

  #include "pmem.h"

  #include "pfn.h"

  #include "nd.h"
  
  static void namespace_io_release(struct device *dev)
  {
  	struct nd_namespace_io *nsio = to_nd_namespace_io(dev);
  
  	kfree(nsio);
  }

  static void namespace_pmem_release(struct device *dev)
  {
  	struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);

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

  	if (nspm->id >= 0)
  		ida_simple_remove(&nd_region->ns_ida, nspm->id);

  	kfree(nspm->alt_name);
  	kfree(nspm->uuid);
  	kfree(nspm);
  }
  
  static void namespace_blk_release(struct device *dev)
  {

  	struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
  	struct nd_region *nd_region = to_nd_region(dev->parent);
  
  	if (nsblk->id >= 0)
  		ida_simple_remove(&nd_region->ns_ida, nsblk->id);
  	kfree(nsblk->alt_name);
  	kfree(nsblk->uuid);
  	kfree(nsblk->res);
  	kfree(nsblk);

  }

  static bool is_namespace_pmem(const struct device *dev);
  static bool is_namespace_blk(const struct device *dev);
  static bool is_namespace_io(const struct device *dev);

  static int is_uuid_busy(struct device *dev, void *data)
  {
  	u8 *uuid1 = data, *uuid2 = NULL;
  
  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
  
  		uuid2 = nspm->uuid;
  	} else if (is_namespace_blk(dev)) {
  		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
  
  		uuid2 = nsblk->uuid;
  	} else if (is_nd_btt(dev)) {
  		struct nd_btt *nd_btt = to_nd_btt(dev);
  
  		uuid2 = nd_btt->uuid;
  	} else if (is_nd_pfn(dev)) {
  		struct nd_pfn *nd_pfn = to_nd_pfn(dev);
  
  		uuid2 = nd_pfn->uuid;
  	}
  
  	if (uuid2 && memcmp(uuid1, uuid2, NSLABEL_UUID_LEN) == 0)
  		return -EBUSY;
  
  	return 0;
  }
  
  static int is_namespace_uuid_busy(struct device *dev, void *data)
  {

  	if (is_nd_region(dev))

  		return device_for_each_child(dev, data, is_uuid_busy);
  	return 0;
  }
  
  /**
   * nd_is_uuid_unique - verify that no other namespace has @uuid
   * @dev: any device on a nvdimm_bus
   * @uuid: uuid to check
   */
  bool nd_is_uuid_unique(struct device *dev, u8 *uuid)
  {
  	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  
  	if (!nvdimm_bus)
  		return false;
  	WARN_ON_ONCE(!is_nvdimm_bus_locked(&nvdimm_bus->dev));
  	if (device_for_each_child(&nvdimm_bus->dev, uuid,
  				is_namespace_uuid_busy) != 0)
  		return false;
  	return true;
  }

  bool pmem_should_map_pages(struct device *dev)
  {
  	struct nd_region *nd_region = to_nd_region(dev->parent);

  	struct nd_namespace_common *ndns = to_ndns(dev);

  	struct nd_namespace_io *nsio;

  
  	if (!IS_ENABLED(CONFIG_ZONE_DEVICE))
  		return false;
  
  	if (!test_bit(ND_REGION_PAGEMAP, &nd_region->flags))
  		return false;
  
  	if (is_nd_pfn(dev) || is_nd_btt(dev))
  		return false;

  	if (ndns->force_raw)
  		return false;

  	nsio = to_nd_namespace_io(dev);
  	if (region_intersects(nsio->res.start, resource_size(&nsio->res),
  				IORESOURCE_SYSTEM_RAM,
  				IORES_DESC_NONE) == REGION_MIXED)
  		return false;

  	return ARCH_MEMREMAP_PMEM == MEMREMAP_WB;

  }
  EXPORT_SYMBOL(pmem_should_map_pages);

  unsigned int pmem_sector_size(struct nd_namespace_common *ndns)
  {
  	if (is_namespace_pmem(&ndns->dev)) {
  		struct nd_namespace_pmem *nspm;
  
  		nspm = to_nd_namespace_pmem(&ndns->dev);
  		if (nspm->lbasize == 0 || nspm->lbasize == 512)
  			/* default */;
  		else if (nspm->lbasize == 4096)
  			return 4096;
  		else
  			dev_WARN(&ndns->dev, "unsupported sector size: %ld
  ",
  					nspm->lbasize);
  	}
  
  	/*
  	 * There is no namespace label (is_namespace_io()), or the label
  	 * indicates the default sector size.
  	 */
  	return 512;
  }
  EXPORT_SYMBOL(pmem_sector_size);

  const char *nvdimm_namespace_disk_name(struct nd_namespace_common *ndns,
  		char *name)
  {
  	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);

  	const char *suffix = NULL;

  	if (ndns->claim && is_nd_btt(ndns->claim))
  		suffix = "s";

  	if (is_namespace_pmem(&ndns->dev) || is_namespace_io(&ndns->dev)) {

  		int nsidx = 0;
  
  		if (is_namespace_pmem(&ndns->dev)) {
  			struct nd_namespace_pmem *nspm;
  
  			nspm = to_nd_namespace_pmem(&ndns->dev);
  			nsidx = nspm->id;
  		}
  
  		if (nsidx)
  			sprintf(name, "pmem%d.%d%s", nd_region->id, nsidx,
  					suffix ? suffix : "");
  		else
  			sprintf(name, "pmem%d%s", nd_region->id,
  					suffix ? suffix : "");

  	} else if (is_namespace_blk(&ndns->dev)) {

  		struct nd_namespace_blk *nsblk;
  
  		nsblk = to_nd_namespace_blk(&ndns->dev);

  		sprintf(name, "ndblk%d.%d%s", nd_region->id, nsblk->id,
  				suffix ? suffix : "");

  	} else {
  		return NULL;
  	}
  
  	return name;
  }
  EXPORT_SYMBOL(nvdimm_namespace_disk_name);

  const u8 *nd_dev_to_uuid(struct device *dev)
  {
  	static const u8 null_uuid[16];
  
  	if (!dev)
  		return null_uuid;
  
  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
  
  		return nspm->uuid;
  	} else if (is_namespace_blk(dev)) {
  		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
  
  		return nsblk->uuid;
  	} else
  		return null_uuid;
  }
  EXPORT_SYMBOL(nd_dev_to_uuid);

  static ssize_t nstype_show(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	struct nd_region *nd_region = to_nd_region(dev->parent);
  
  	return sprintf(buf, "%d
  ", nd_region_to_nstype(nd_region));
  }
  static DEVICE_ATTR_RO(nstype);

  static ssize_t __alt_name_store(struct device *dev, const char *buf,
  		const size_t len)
  {
  	char *input, *pos, *alt_name, **ns_altname;
  	ssize_t rc;
  
  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
  
  		ns_altname = &nspm->alt_name;
  	} else if (is_namespace_blk(dev)) {

  		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
  
  		ns_altname = &nsblk->alt_name;

  	} else
  		return -ENXIO;

  	if (dev->driver || to_ndns(dev)->claim)

  		return -EBUSY;

  	input = kstrndup(buf, len, GFP_KERNEL);

  	if (!input)
  		return -ENOMEM;

  	pos = strim(input);
  	if (strlen(pos) + 1 > NSLABEL_NAME_LEN) {
  		rc = -EINVAL;
  		goto out;
  	}
  
  	alt_name = kzalloc(NSLABEL_NAME_LEN, GFP_KERNEL);
  	if (!alt_name) {
  		rc = -ENOMEM;
  		goto out;
  	}
  	kfree(*ns_altname);
  	*ns_altname = alt_name;
  	sprintf(*ns_altname, "%s", pos);
  	rc = len;
  
  out:
  	kfree(input);
  	return rc;
  }

  static resource_size_t nd_namespace_blk_size(struct nd_namespace_blk *nsblk)
  {

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

  	struct nd_mapping *nd_mapping = &nd_region->mapping[0];
  	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
  	struct nd_label_id label_id;
  	resource_size_t size = 0;
  	struct resource *res;
  
  	if (!nsblk->uuid)
  		return 0;
  	nd_label_gen_id(&label_id, nsblk->uuid, NSLABEL_FLAG_LOCAL);
  	for_each_dpa_resource(ndd, res)
  		if (strcmp(res->name, label_id.id) == 0)
  			size += resource_size(res);
  	return size;
  }

  static bool __nd_namespace_blk_validate(struct nd_namespace_blk *nsblk)
  {
  	struct nd_region *nd_region = to_nd_region(nsblk->common.dev.parent);
  	struct nd_mapping *nd_mapping = &nd_region->mapping[0];
  	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
  	struct nd_label_id label_id;
  	struct resource *res;
  	int count, i;
  
  	if (!nsblk->uuid || !nsblk->lbasize || !ndd)
  		return false;
  
  	count = 0;
  	nd_label_gen_id(&label_id, nsblk->uuid, NSLABEL_FLAG_LOCAL);
  	for_each_dpa_resource(ndd, res) {
  		if (strcmp(res->name, label_id.id) != 0)
  			continue;
  		/*

  		 * Resources with unacknowledged adjustments indicate a

  		 * failure to update labels
  		 */
  		if (res->flags & DPA_RESOURCE_ADJUSTED)
  			return false;
  		count++;
  	}
  
  	/* These values match after a successful label update */
  	if (count != nsblk->num_resources)
  		return false;
  
  	for (i = 0; i < nsblk->num_resources; i++) {
  		struct resource *found = NULL;
  
  		for_each_dpa_resource(ndd, res)
  			if (res == nsblk->res[i]) {
  				found = res;
  				break;
  			}
  		/* stale resource */
  		if (!found)
  			return false;
  	}
  
  	return true;
  }
  
  resource_size_t nd_namespace_blk_validate(struct nd_namespace_blk *nsblk)
  {
  	resource_size_t size;
  
  	nvdimm_bus_lock(&nsblk->common.dev);
  	size = __nd_namespace_blk_validate(nsblk);
  	nvdimm_bus_unlock(&nsblk->common.dev);
  
  	return size;
  }
  EXPORT_SYMBOL(nd_namespace_blk_validate);

  static int nd_namespace_label_update(struct nd_region *nd_region,
  		struct device *dev)
  {

  	dev_WARN_ONCE(dev, dev->driver || to_ndns(dev)->claim,

  			"namespace must be idle during label update
  ");

  	if (dev->driver || to_ndns(dev)->claim)

  		return 0;
  
  	/*
  	 * Only allow label writes that will result in a valid namespace
  	 * or deletion of an existing namespace.
  	 */
  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);

  		resource_size_t size = resource_size(&nspm->nsio.res);

  
  		if (size == 0 && nspm->uuid)
  			/* delete allocation */;
  		else if (!nspm->uuid)
  			return 0;
  
  		return nd_pmem_namespace_label_update(nd_region, nspm, size);
  	} else if (is_namespace_blk(dev)) {

  		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
  		resource_size_t size = nd_namespace_blk_size(nsblk);
  
  		if (size == 0 && nsblk->uuid)
  			/* delete allocation */;
  		else if (!nsblk->uuid || !nsblk->lbasize)
  			return 0;
  
  		return nd_blk_namespace_label_update(nd_region, nsblk, size);

  	} else
  		return -ENXIO;
  }

  static ssize_t alt_name_store(struct device *dev,
  		struct device_attribute *attr, const char *buf, size_t len)
  {

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

  	ssize_t rc;

  	nd_device_lock(dev);

  	nvdimm_bus_lock(dev);
  	wait_nvdimm_bus_probe_idle(dev);
  	rc = __alt_name_store(dev, buf, len);

  	if (rc >= 0)
  		rc = nd_namespace_label_update(nd_region, dev);

  	dev_dbg(dev, "%s(%zd)
  ", rc < 0 ? "fail " : "", rc);

  	nvdimm_bus_unlock(dev);

  	nd_device_unlock(dev);

  	return rc < 0 ? rc : len;

  }
  
  static ssize_t alt_name_show(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	char *ns_altname;
  
  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
  
  		ns_altname = nspm->alt_name;
  	} else if (is_namespace_blk(dev)) {

  		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
  
  		ns_altname = nsblk->alt_name;

  	} else
  		return -ENXIO;
  
  	return sprintf(buf, "%s
  ", ns_altname ? ns_altname : "");
  }
  static DEVICE_ATTR_RW(alt_name);
  
  static int scan_free(struct nd_region *nd_region,
  		struct nd_mapping *nd_mapping, struct nd_label_id *label_id,
  		resource_size_t n)
  {
  	bool is_blk = strncmp(label_id->id, "blk", 3) == 0;
  	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
  	int rc = 0;
  
  	while (n) {
  		struct resource *res, *last;
  		resource_size_t new_start;
  
  		last = NULL;
  		for_each_dpa_resource(ndd, res)
  			if (strcmp(res->name, label_id->id) == 0)
  				last = res;
  		res = last;
  		if (!res)
  			return 0;
  
  		if (n >= resource_size(res)) {
  			n -= resource_size(res);
  			nd_dbg_dpa(nd_region, ndd, res, "delete %d
  ", rc);
  			nvdimm_free_dpa(ndd, res);
  			/* retry with last resource deleted */
  			continue;
  		}
  
  		/*
  		 * Keep BLK allocations relegated to high DPA as much as
  		 * possible
  		 */
  		if (is_blk)
  			new_start = res->start + n;
  		else
  			new_start = res->start;
  
  		rc = adjust_resource(res, new_start, resource_size(res) - n);

  		if (rc == 0)
  			res->flags |= DPA_RESOURCE_ADJUSTED;

  		nd_dbg_dpa(nd_region, ndd, res, "shrink %d
  ", rc);
  		break;
  	}
  
  	return rc;
  }
  
  /**
   * shrink_dpa_allocation - for each dimm in region free n bytes for label_id
   * @nd_region: the set of dimms to reclaim @n bytes from
   * @label_id: unique identifier for the namespace consuming this dpa range
   * @n: number of bytes per-dimm to release
   *
   * Assumes resources are ordered.  Starting from the end try to
   * adjust_resource() the allocation to @n, but if @n is larger than the
   * allocation delete it and find the 'new' last allocation in the label
   * set.
   */
  static int shrink_dpa_allocation(struct nd_region *nd_region,
  		struct nd_label_id *label_id, resource_size_t n)
  {
  	int i;
  
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
  		int rc;
  
  		rc = scan_free(nd_region, nd_mapping, label_id, n);
  		if (rc)
  			return rc;
  	}
  
  	return 0;
  }
  
  static resource_size_t init_dpa_allocation(struct nd_label_id *label_id,
  		struct nd_region *nd_region, struct nd_mapping *nd_mapping,
  		resource_size_t n)
  {
  	bool is_blk = strncmp(label_id->id, "blk", 3) == 0;
  	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
  	resource_size_t first_dpa;
  	struct resource *res;
  	int rc = 0;
  
  	/* allocate blk from highest dpa first */
  	if (is_blk)
  		first_dpa = nd_mapping->start + nd_mapping->size - n;
  	else
  		first_dpa = nd_mapping->start;
  
  	/* first resource allocation for this label-id or dimm */
  	res = nvdimm_allocate_dpa(ndd, label_id, first_dpa, n);
  	if (!res)
  		rc = -EBUSY;
  
  	nd_dbg_dpa(nd_region, ndd, res, "init %d
  ", rc);
  	return rc ? n : 0;
  }

  
  /**
   * space_valid() - validate free dpa space against constraints
   * @nd_region: hosting region of the free space
   * @ndd: dimm device data for debug
   * @label_id: namespace id to allocate space
   * @prev: potential allocation that precedes free space
   * @next: allocation that follows the given free space range
   * @exist: first allocation with same id in the mapping
   * @n: range that must satisfied for pmem allocations
   * @valid: free space range to validate
   *
   * BLK-space is valid as long as it does not precede a PMEM
   * allocation in a given region. PMEM-space must be contiguous
   * and adjacent to an existing existing allocation (if one
   * exists).  If reserving PMEM any space is valid.
   */
  static void space_valid(struct nd_region *nd_region, struct nvdimm_drvdata *ndd,
  		struct nd_label_id *label_id, struct resource *prev,
  		struct resource *next, struct resource *exist,
  		resource_size_t n, struct resource *valid)

  {

  	bool is_reserve = strcmp(label_id->id, "pmem-reserve") == 0;
  	bool is_pmem = strncmp(label_id->id, "pmem", 4) == 0;

  	unsigned long align;
  
  	align = nd_region->align / nd_region->ndr_mappings;
  	valid->start = ALIGN(valid->start, align);
  	valid->end = ALIGN_DOWN(valid->end + 1, align) - 1;

  
  	if (valid->start >= valid->end)
  		goto invalid;
  
  	if (is_reserve)
  		return;
  
  	if (!is_pmem) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[0];
  		struct nvdimm_bus *nvdimm_bus;
  		struct blk_alloc_info info = {
  			.nd_mapping = nd_mapping,
  			.available = nd_mapping->size,
  			.res = valid,
  		};
  
  		WARN_ON(!is_nd_blk(&nd_region->dev));
  		nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
  		device_for_each_child(&nvdimm_bus->dev, &info, alias_dpa_busy);
  		return;
  	}
  
  	/* allocation needs to be contiguous, so this is all or nothing */
  	if (resource_size(valid) < n)
  		goto invalid;
  
  	/* we've got all the space we need and no existing allocation */
  	if (!exist)
  		return;
  
  	/* allocation needs to be contiguous with the existing namespace */
  	if (valid->start == exist->end + 1
  			|| valid->end == exist->start - 1)
  		return;
  
   invalid:
  	/* truncate @valid size to 0 */
  	valid->end = valid->start - 1;

  }
  
  enum alloc_loc {
  	ALLOC_ERR = 0, ALLOC_BEFORE, ALLOC_MID, ALLOC_AFTER,
  };
  
  static resource_size_t scan_allocate(struct nd_region *nd_region,
  		struct nd_mapping *nd_mapping, struct nd_label_id *label_id,
  		resource_size_t n)
  {
  	resource_size_t mapping_end = nd_mapping->start + nd_mapping->size - 1;
  	bool is_pmem = strncmp(label_id->id, "pmem", 4) == 0;
  	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);

  	struct resource *res, *exist = NULL, valid;

  	const resource_size_t to_allocate = n;

  	int first;

  	for_each_dpa_resource(ndd, res)
  		if (strcmp(label_id->id, res->name) == 0)
  			exist = res;
  
  	valid.start = nd_mapping->start;
  	valid.end = mapping_end;
  	valid.name = "free space";

   retry:
  	first = 0;
  	for_each_dpa_resource(ndd, res) {

  		struct resource *next = res->sibling, *new_res = NULL;

  		resource_size_t allocate, available = 0;

  		enum alloc_loc loc = ALLOC_ERR;
  		const char *action;
  		int rc = 0;
  
  		/* ignore resources outside this nd_mapping */
  		if (res->start > mapping_end)
  			continue;
  		if (res->end < nd_mapping->start)
  			continue;
  
  		/* space at the beginning of the mapping */
  		if (!first++ && res->start > nd_mapping->start) {

  			valid.start = nd_mapping->start;
  			valid.end = res->start - 1;
  			space_valid(nd_region, ndd, label_id, NULL, next, exist,
  					to_allocate, &valid);
  			available = resource_size(&valid);
  			if (available)

  				loc = ALLOC_BEFORE;
  		}
  
  		/* space between allocations */
  		if (!loc && next) {

  			valid.start = res->start + resource_size(res);
  			valid.end = min(mapping_end, next->start - 1);
  			space_valid(nd_region, ndd, label_id, res, next, exist,
  					to_allocate, &valid);
  			available = resource_size(&valid);
  			if (available)

  				loc = ALLOC_MID;

  		}
  
  		/* space at the end of the mapping */
  		if (!loc && !next) {

  			valid.start = res->start + resource_size(res);
  			valid.end = mapping_end;
  			space_valid(nd_region, ndd, label_id, res, next, exist,
  					to_allocate, &valid);
  			available = resource_size(&valid);
  			if (available)

  				loc = ALLOC_AFTER;

  		}
  
  		if (!loc || !available)
  			continue;
  		allocate = min(available, n);
  		switch (loc) {
  		case ALLOC_BEFORE:
  			if (strcmp(res->name, label_id->id) == 0) {
  				/* adjust current resource up */

  				rc = adjust_resource(res, res->start - allocate,
  						resource_size(res) + allocate);
  				action = "cur grow up";
  			} else
  				action = "allocate";
  			break;
  		case ALLOC_MID:
  			if (strcmp(next->name, label_id->id) == 0) {
  				/* adjust next resource up */

  				rc = adjust_resource(next, next->start
  						- allocate, resource_size(next)
  						+ allocate);
  				new_res = next;
  				action = "next grow up";
  			} else if (strcmp(res->name, label_id->id) == 0) {
  				action = "grow down";
  			} else
  				action = "allocate";
  			break;
  		case ALLOC_AFTER:
  			if (strcmp(res->name, label_id->id) == 0)
  				action = "grow down";
  			else
  				action = "allocate";
  			break;
  		default:
  			return n;
  		}
  
  		if (strcmp(action, "allocate") == 0) {
  			/* BLK allocate bottom up */
  			if (!is_pmem)

  				valid.start += available - allocate;

  
  			new_res = nvdimm_allocate_dpa(ndd, label_id,

  					valid.start, allocate);

  			if (!new_res)
  				rc = -EBUSY;
  		} else if (strcmp(action, "grow down") == 0) {
  			/* adjust current resource down */
  			rc = adjust_resource(res, res->start, resource_size(res)
  					+ allocate);

  			if (rc == 0)
  				res->flags |= DPA_RESOURCE_ADJUSTED;

  		}
  
  		if (!new_res)
  			new_res = res;
  
  		nd_dbg_dpa(nd_region, ndd, new_res, "%s(%d) %d
  ",
  				action, loc, rc);
  
  		if (rc)
  			return n;
  
  		n -= allocate;
  		if (n) {
  			/*
  			 * Retry scan with newly inserted resources.
  			 * For example, if we did an ALLOC_BEFORE
  			 * insertion there may also have been space
  			 * available for an ALLOC_AFTER insertion, so we
  			 * need to check this same resource again
  			 */
  			goto retry;
  		} else
  			return 0;
  	}

  	/*
  	 * If we allocated nothing in the BLK case it may be because we are in
  	 * an initial "pmem-reserve pass".  Only do an initial BLK allocation
  	 * when none of the DPA space is reserved.
  	 */
  	if ((is_pmem || !ndd->dpa.child) && n == to_allocate)

  		return init_dpa_allocation(label_id, nd_region, nd_mapping, n);
  	return n;
  }

  static int merge_dpa(struct nd_region *nd_region,
  		struct nd_mapping *nd_mapping, struct nd_label_id *label_id)
  {
  	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
  	struct resource *res;
  
  	if (strncmp("pmem", label_id->id, 4) == 0)
  		return 0;
   retry:
  	for_each_dpa_resource(ndd, res) {
  		int rc;
  		struct resource *next = res->sibling;
  		resource_size_t end = res->start + resource_size(res);
  
  		if (!next || strcmp(res->name, label_id->id) != 0
  				|| strcmp(next->name, label_id->id) != 0
  				|| end != next->start)
  			continue;
  		end += resource_size(next);
  		nvdimm_free_dpa(ndd, next);
  		rc = adjust_resource(res, res->start, end - res->start);
  		nd_dbg_dpa(nd_region, ndd, res, "merge %d
  ", rc);
  		if (rc)
  			return rc;
  		res->flags |= DPA_RESOURCE_ADJUSTED;
  		goto retry;
  	}
  
  	return 0;
  }

  int __reserve_free_pmem(struct device *dev, void *data)

  {
  	struct nvdimm *nvdimm = data;
  	struct nd_region *nd_region;
  	struct nd_label_id label_id;
  	int i;

  	if (!is_memory(dev))

  		return 0;
  
  	nd_region = to_nd_region(dev);
  	if (nd_region->ndr_mappings == 0)
  		return 0;
  
  	memset(&label_id, 0, sizeof(label_id));
  	strcat(label_id.id, "pmem-reserve");
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
  		resource_size_t n, rem = 0;
  
  		if (nd_mapping->nvdimm != nvdimm)
  			continue;
  
  		n = nd_pmem_available_dpa(nd_region, nd_mapping, &rem);
  		if (n == 0)
  			return 0;
  		rem = scan_allocate(nd_region, nd_mapping, &label_id, n);
  		dev_WARN_ONCE(&nd_region->dev, rem,
  				"pmem reserve underrun: %#llx of %#llx bytes
  ",
  				(unsigned long long) n - rem,
  				(unsigned long long) n);
  		return rem ? -ENXIO : 0;
  	}
  
  	return 0;
  }

  void release_free_pmem(struct nvdimm_bus *nvdimm_bus,

  		struct nd_mapping *nd_mapping)
  {
  	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
  	struct resource *res, *_res;
  
  	for_each_dpa_resource_safe(ndd, res, _res)
  		if (strcmp(res->name, "pmem-reserve") == 0)
  			nvdimm_free_dpa(ndd, res);
  }
  
  static int reserve_free_pmem(struct nvdimm_bus *nvdimm_bus,
  		struct nd_mapping *nd_mapping)
  {
  	struct nvdimm *nvdimm = nd_mapping->nvdimm;
  	int rc;
  
  	rc = device_for_each_child(&nvdimm_bus->dev, nvdimm,
  			__reserve_free_pmem);
  	if (rc)
  		release_free_pmem(nvdimm_bus, nd_mapping);
  	return rc;
  }

  /**
   * grow_dpa_allocation - for each dimm allocate n bytes for @label_id
   * @nd_region: the set of dimms to allocate @n more bytes from
   * @label_id: unique identifier for the namespace consuming this dpa range
   * @n: number of bytes per-dimm to add to the existing allocation
   *
   * Assumes resources are ordered.  For BLK regions, first consume
   * BLK-only available DPA free space, then consume PMEM-aliased DPA
   * space starting at the highest DPA.  For PMEM regions start
   * allocations from the start of an interleave set and end at the first
   * BLK allocation or the end of the interleave set, whichever comes
   * first.
   */
  static int grow_dpa_allocation(struct nd_region *nd_region,
  		struct nd_label_id *label_id, resource_size_t n)
  {

  	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
  	bool is_pmem = strncmp(label_id->id, "pmem", 4) == 0;

  	int i;
  
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[i];

  		resource_size_t rem = n;
  		int rc, j;
  
  		/*
  		 * In the BLK case try once with all unallocated PMEM
  		 * reserved, and once without
  		 */
  		for (j = is_pmem; j < 2; j++) {
  			bool blk_only = j == 0;
  
  			if (blk_only) {
  				rc = reserve_free_pmem(nvdimm_bus, nd_mapping);
  				if (rc)
  					return rc;
  			}
  			rem = scan_allocate(nd_region, nd_mapping,
  					label_id, rem);
  			if (blk_only)
  				release_free_pmem(nvdimm_bus, nd_mapping);

  			/* try again and allow encroachments into PMEM */
  			if (rem == 0)
  				break;
  		}
  
  		dev_WARN_ONCE(&nd_region->dev, rem,
  				"allocation underrun: %#llx of %#llx bytes
  ",
  				(unsigned long long) n - rem,
  				(unsigned long long) n);
  		if (rem)
  			return -ENXIO;
  
  		rc = merge_dpa(nd_region, nd_mapping, label_id);

  		if (rc)
  			return rc;
  	}
  
  	return 0;
  }

  static void nd_namespace_pmem_set_resource(struct nd_region *nd_region,

  		struct nd_namespace_pmem *nspm, resource_size_t size)
  {
  	struct resource *res = &nspm->nsio.res;

  	resource_size_t offset = 0;

  	if (size && !nspm->uuid) {
  		WARN_ON_ONCE(1);
  		size = 0;
  	}
  
  	if (size && nspm->uuid) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[0];
  		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
  		struct nd_label_id label_id;
  		struct resource *res;
  
  		if (!ndd) {
  			size = 0;
  			goto out;
  		}
  
  		nd_label_gen_id(&label_id, nspm->uuid, 0);
  
  		/* calculate a spa offset from the dpa allocation offset */
  		for_each_dpa_resource(ndd, res)
  			if (strcmp(res->name, label_id.id) == 0) {
  				offset = (res->start - nd_mapping->start)
  					* nd_region->ndr_mappings;
  				goto out;
  			}
  
  		WARN_ON_ONCE(1);
  		size = 0;
  	}
  
   out:
  	res->start = nd_region->ndr_start + offset;
  	res->end = res->start + size - 1;

  }

  static bool uuid_not_set(const u8 *uuid, struct device *dev, const char *where)
  {
  	if (!uuid) {
  		dev_dbg(dev, "%s: uuid not set
  ", where);
  		return true;
  	}
  	return false;
  }

  static ssize_t __size_store(struct device *dev, unsigned long long val)
  {
  	resource_size_t allocated = 0, available = 0;
  	struct nd_region *nd_region = to_nd_region(dev->parent);

  	struct nd_namespace_common *ndns = to_ndns(dev);

  	struct nd_mapping *nd_mapping;
  	struct nvdimm_drvdata *ndd;
  	struct nd_label_id label_id;
  	u32 flags = 0, remainder;

  	int rc, i, id = -1;

  	u8 *uuid = NULL;

  	if (dev->driver || ndns->claim)

  		return -EBUSY;
  
  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
  
  		uuid = nspm->uuid;

  		id = nspm->id;

  	} else if (is_namespace_blk(dev)) {

  		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
  
  		uuid = nsblk->uuid;
  		flags = NSLABEL_FLAG_LOCAL;

  		id = nsblk->id;

  	}
  
  	/*
  	 * We need a uuid for the allocation-label and dimm(s) on which
  	 * to store the label.
  	 */

  	if (uuid_not_set(uuid, dev, __func__))

  		return -ENXIO;

  	if (nd_region->ndr_mappings == 0) {

  		dev_dbg(dev, "not associated with dimm(s)
  ");

  		return -ENXIO;
  	}

  	div_u64_rem(val, nd_region->align, &remainder);

  	if (remainder) {

  		dev_dbg(dev, "%llu is not %ldK aligned
  ", val,

  				nd_region->align / SZ_1K);

  		return -EINVAL;
  	}
  
  	nd_label_gen_id(&label_id, uuid, flags);
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		nd_mapping = &nd_region->mapping[i];
  		ndd = to_ndd(nd_mapping);
  
  		/*
  		 * All dimms in an interleave set, or the base dimm for a blk
  		 * region, need to be enabled for the size to be changed.
  		 */
  		if (!ndd)
  			return -ENXIO;
  
  		allocated += nvdimm_allocated_dpa(ndd, &label_id);
  	}

  	available = nd_region_allocatable_dpa(nd_region);

  
  	if (val > available + allocated)
  		return -ENOSPC;
  
  	if (val == allocated)
  		return 0;
  
  	val = div_u64(val, nd_region->ndr_mappings);
  	allocated = div_u64(allocated, nd_region->ndr_mappings);
  	if (val < allocated)
  		rc = shrink_dpa_allocation(nd_region, &label_id,
  				allocated - val);
  	else
  		rc = grow_dpa_allocation(nd_region, &label_id, val - allocated);
  
  	if (rc)
  		return rc;
  
  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);

  		nd_namespace_pmem_set_resource(nd_region, nspm,

  				val * nd_region->ndr_mappings);
  	}

  	/*
  	 * Try to delete the namespace if we deleted all of its

  	 * allocation, this is not the seed or 0th device for the
  	 * region, and it is not actively claimed by a btt, pfn, or dax
  	 * instance.

  	 */

  	if (val == 0 && id != 0 && nd_region->ns_seed != dev && !ndns->claim)

  		nd_device_unregister(dev, ND_ASYNC);

  	return rc;
  }
  
  static ssize_t size_store(struct device *dev,
  		struct device_attribute *attr, const char *buf, size_t len)
  {

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

  	unsigned long long val;
  	u8 **uuid = NULL;
  	int rc;
  
  	rc = kstrtoull(buf, 0, &val);
  	if (rc)
  		return rc;

  	nd_device_lock(dev);

  	nvdimm_bus_lock(dev);
  	wait_nvdimm_bus_probe_idle(dev);
  	rc = __size_store(dev, val);

  	if (rc >= 0)
  		rc = nd_namespace_label_update(nd_region, dev);

  
  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
  
  		uuid = &nspm->uuid;
  	} else if (is_namespace_blk(dev)) {

  		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
  
  		uuid = &nsblk->uuid;

  	}
  
  	if (rc == 0 && val == 0 && uuid) {
  		/* setting size zero == 'delete namespace' */
  		kfree(*uuid);
  		*uuid = NULL;
  	}

  	dev_dbg(dev, "%llx %s (%d)
  ", val, rc < 0 ? "fail" : "success", rc);

  
  	nvdimm_bus_unlock(dev);

  	nd_device_unlock(dev);

  	return rc < 0 ? rc : len;

  }

  resource_size_t __nvdimm_namespace_capacity(struct nd_namespace_common *ndns)

  {

  	struct device *dev = &ndns->dev;

  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);

  		return resource_size(&nspm->nsio.res);

  	} else if (is_namespace_blk(dev)) {

  		return nd_namespace_blk_size(to_nd_namespace_blk(dev));

  	} else if (is_namespace_io(dev)) {
  		struct nd_namespace_io *nsio = to_nd_namespace_io(dev);

  		return resource_size(&nsio->res);
  	} else
  		WARN_ONCE(1, "unknown namespace type
  ");
  	return 0;
  }
  
  resource_size_t nvdimm_namespace_capacity(struct nd_namespace_common *ndns)
  {
  	resource_size_t size;

  	nvdimm_bus_lock(&ndns->dev);
  	size = __nvdimm_namespace_capacity(ndns);
  	nvdimm_bus_unlock(&ndns->dev);
  
  	return size;
  }
  EXPORT_SYMBOL(nvdimm_namespace_capacity);

  bool nvdimm_namespace_locked(struct nd_namespace_common *ndns)
  {
  	int i;
  	bool locked = false;
  	struct device *dev = &ndns->dev;
  	struct nd_region *nd_region = to_nd_region(dev->parent);
  
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
  		struct nvdimm *nvdimm = nd_mapping->nvdimm;
  
  		if (test_bit(NDD_LOCKED, &nvdimm->flags)) {
  			dev_dbg(dev, "%s locked
  ", nvdimm_name(nvdimm));
  			locked = true;
  		}
  	}
  	return locked;
  }
  EXPORT_SYMBOL(nvdimm_namespace_locked);

  static ssize_t size_show(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	return sprintf(buf, "%llu
  ", (unsigned long long)
  			nvdimm_namespace_capacity(to_ndns(dev)));

  }

  static DEVICE_ATTR(size, 0444, size_show, size_store);

  static u8 *namespace_to_uuid(struct device *dev)

  {

  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);

  		return nspm->uuid;

  	} else if (is_namespace_blk(dev)) {

  		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);

  		return nsblk->uuid;

  	} else

  		return ERR_PTR(-ENXIO);
  }
  
  static ssize_t uuid_show(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	u8 *uuid = namespace_to_uuid(dev);

  	if (IS_ERR(uuid))
  		return PTR_ERR(uuid);

  	if (uuid)
  		return sprintf(buf, "%pUb
  ", uuid);
  	return sprintf(buf, "
  ");
  }
  
  /**
   * namespace_update_uuid - check for a unique uuid and whether we're "renaming"
   * @nd_region: parent region so we can updates all dimms in the set
   * @dev: namespace type for generating label_id
   * @new_uuid: incoming uuid
   * @old_uuid: reference to the uuid storage location in the namespace object
   */
  static int namespace_update_uuid(struct nd_region *nd_region,
  		struct device *dev, u8 *new_uuid, u8 **old_uuid)
  {
  	u32 flags = is_namespace_blk(dev) ? NSLABEL_FLAG_LOCAL : 0;
  	struct nd_label_id old_label_id;
  	struct nd_label_id new_label_id;

  	int i;

  	if (!nd_is_uuid_unique(dev, new_uuid))
  		return -EINVAL;

  
  	if (*old_uuid == NULL)
  		goto out;

  	/*
  	 * If we've already written a label with this uuid, then it's
  	 * too late to rename because we can't reliably update the uuid
  	 * without losing the old namespace.  Userspace must delete this
  	 * namespace to abandon the old uuid.
  	 */
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
  
  		/*
  		 * This check by itself is sufficient because old_uuid
  		 * would be NULL above if this uuid did not exist in the
  		 * currently written set.
  		 *
  		 * FIXME: can we delete uuid with zero dpa allocated?
  		 */

  		if (list_empty(&nd_mapping->labels))

  			return -EBUSY;
  	}

  	nd_label_gen_id(&old_label_id, *old_uuid, flags);
  	nd_label_gen_id(&new_label_id, new_uuid, flags);
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
  		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);

  		struct nd_label_ent *label_ent;

  		struct resource *res;
  
  		for_each_dpa_resource(ndd, res)
  			if (strcmp(res->name, old_label_id.id) == 0)
  				sprintf((void *) res->name, "%s",
  						new_label_id.id);

  
  		mutex_lock(&nd_mapping->lock);
  		list_for_each_entry(label_ent, &nd_mapping->labels, list) {
  			struct nd_namespace_label *nd_label = label_ent->label;
  			struct nd_label_id label_id;
  
  			if (!nd_label)
  				continue;
  			nd_label_gen_id(&label_id, nd_label->uuid,
  					__le32_to_cpu(nd_label->flags));
  			if (strcmp(old_label_id.id, label_id.id) == 0)
  				set_bit(ND_LABEL_REAP, &label_ent->flags);
  		}
  		mutex_unlock(&nd_mapping->lock);

  	}
  	kfree(*old_uuid);
   out:
  	*old_uuid = new_uuid;
  	return 0;
  }
  
  static ssize_t uuid_store(struct device *dev,
  		struct device_attribute *attr, const char *buf, size_t len)
  {
  	struct nd_region *nd_region = to_nd_region(dev->parent);
  	u8 *uuid = NULL;

  	ssize_t rc = 0;

  	u8 **ns_uuid;

  
  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
  
  		ns_uuid = &nspm->uuid;
  	} else if (is_namespace_blk(dev)) {

  		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
  
  		ns_uuid = &nsblk->uuid;

  	} else
  		return -ENXIO;

  	nd_device_lock(dev);

  	nvdimm_bus_lock(dev);
  	wait_nvdimm_bus_probe_idle(dev);

  	if (to_ndns(dev)->claim)
  		rc = -EBUSY;
  	if (rc >= 0)
  		rc = nd_uuid_store(dev, &uuid, buf, len);

  	if (rc >= 0)
  		rc = namespace_update_uuid(nd_region, dev, uuid, ns_uuid);

  	if (rc >= 0)
  		rc = nd_namespace_label_update(nd_region, dev);
  	else
  		kfree(uuid);

  	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
  			buf[len - 1] == '
  ' ? "" : "
  ");

  	nvdimm_bus_unlock(dev);

  	nd_device_unlock(dev);

  	return rc < 0 ? rc : len;

  }
  static DEVICE_ATTR_RW(uuid);
  
  static ssize_t resource_show(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	struct resource *res;
  
  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
  
  		res = &nspm->nsio.res;
  	} else if (is_namespace_io(dev)) {
  		struct nd_namespace_io *nsio = to_nd_namespace_io(dev);
  
  		res = &nsio->res;
  	} else
  		return -ENXIO;
  
  	/* no address to convey if the namespace has no allocation */
  	if (resource_size(res) == 0)
  		return -ENXIO;
  	return sprintf(buf, "%#llx
  ", (unsigned long long) res->start);
  }

  static DEVICE_ATTR_ADMIN_RO(resource);

  static const unsigned long blk_lbasize_supported[] = { 512, 520, 528,

  	4096, 4104, 4160, 4224, 0 };

  static const unsigned long pmem_lbasize_supported[] = { 512, 4096, 0 };

  static ssize_t sector_size_show(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {

  	if (is_namespace_blk(dev)) {
  		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);

  		return nd_size_select_show(nsblk->lbasize,

  				blk_lbasize_supported, buf);
  	}

  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);

  		return nd_size_select_show(nspm->lbasize,

  				pmem_lbasize_supported, buf);
  	}
  	return -ENXIO;

  }
  
  static ssize_t sector_size_store(struct device *dev,
  		struct device_attribute *attr, const char *buf, size_t len)
  {

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

  	const unsigned long *supported;
  	unsigned long *lbasize;

  	ssize_t rc = 0;

  	if (is_namespace_blk(dev)) {
  		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
  
  		lbasize = &nsblk->lbasize;
  		supported = blk_lbasize_supported;
  	} else if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
  
  		lbasize = &nspm->lbasize;
  		supported = pmem_lbasize_supported;
  	} else

  		return -ENXIO;

  	nd_device_lock(dev);

  	nvdimm_bus_lock(dev);

  	if (to_ndns(dev)->claim)
  		rc = -EBUSY;
  	if (rc >= 0)

  		rc = nd_size_select_store(dev, buf, lbasize, supported);

  	if (rc >= 0)
  		rc = nd_namespace_label_update(nd_region, dev);

  	dev_dbg(dev, "result: %zd %s: %s%s", rc, rc < 0 ? "tried" : "wrote",
  			buf, buf[len - 1] == '
  ' ? "" : "
  ");

  	nvdimm_bus_unlock(dev);

  	nd_device_unlock(dev);

  
  	return rc ? rc : len;
  }
  static DEVICE_ATTR_RW(sector_size);

  static ssize_t dpa_extents_show(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	struct nd_region *nd_region = to_nd_region(dev->parent);
  	struct nd_label_id label_id;
  	int count = 0, i;
  	u8 *uuid = NULL;
  	u32 flags = 0;
  
  	nvdimm_bus_lock(dev);
  	if (is_namespace_pmem(dev)) {
  		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
  
  		uuid = nspm->uuid;
  		flags = 0;
  	} else if (is_namespace_blk(dev)) {
  		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
  
  		uuid = nsblk->uuid;
  		flags = NSLABEL_FLAG_LOCAL;
  	}
  
  	if (!uuid)
  		goto out;
  
  	nd_label_gen_id(&label_id, uuid, flags);
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
  		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
  		struct resource *res;
  
  		for_each_dpa_resource(ndd, res)
  			if (strcmp(res->name, label_id.id) == 0)
  				count++;
  	}
   out:
  	nvdimm_bus_unlock(dev);
  
  	return sprintf(buf, "%d
  ", count);
  }
  static DEVICE_ATTR_RO(dpa_extents);

  static int btt_claim_class(struct device *dev)
  {
  	struct nd_region *nd_region = to_nd_region(dev->parent);
  	int i, loop_bitmask = 0;
  
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
  		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
  		struct nd_namespace_index *nsindex;

  		/*
  		 * If any of the DIMMs do not support labels the only
  		 * possible BTT format is v1.
  		 */
  		if (!ndd) {
  			loop_bitmask = 0;
  			break;
  		}

  		nsindex = to_namespace_index(ndd, ndd->ns_current);
  		if (nsindex == NULL)
  			loop_bitmask |= 1;
  		else {
  			/* check whether existing labels are v1.1 or v1.2 */
  			if (__le16_to_cpu(nsindex->major) == 1
  					&& __le16_to_cpu(nsindex->minor) == 1)
  				loop_bitmask |= 2;
  			else
  				loop_bitmask |= 4;
  		}
  	}
  	/*
  	 * If nsindex is null loop_bitmask's bit 0 will be set, and if an index
  	 * block is found, a v1.1 label for any mapping will set bit 1, and a
  	 * v1.2 label will set bit 2.
  	 *
  	 * At the end of the loop, at most one of the three bits must be set.
  	 * If multiple bits were set, it means the different mappings disagree
  	 * about their labels, and this must be cleaned up first.
  	 *
  	 * If all the label index blocks are found to agree, nsindex of NULL
  	 * implies labels haven't been initialized yet, and when they will,
  	 * they will be of the 1.2 format, so we can assume BTT2.0
  	 *
  	 * If 1.1 labels are found, we enforce BTT1.1, and if 1.2 labels are
  	 * found, we enforce BTT2.0
  	 *
  	 * If the loop was never entered, default to BTT1.1 (legacy namespaces)
  	 */
  	switch (loop_bitmask) {
  	case 0:
  	case 2:
  		return NVDIMM_CCLASS_BTT;
  	case 1:
  	case 4:
  		return NVDIMM_CCLASS_BTT2;
  	default:
  		return -ENXIO;
  	}
  }

  static ssize_t holder_show(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	struct nd_namespace_common *ndns = to_ndns(dev);
  	ssize_t rc;

  	nd_device_lock(dev);

  	rc = sprintf(buf, "%s
  ", ndns->claim ? dev_name(ndns->claim) : "");

  	nd_device_unlock(dev);

  
  	return rc;
  }
  static DEVICE_ATTR_RO(holder);

  static int __holder_class_store(struct device *dev, const char *buf)

  {
  	struct nd_namespace_common *ndns = to_ndns(dev);
  
  	if (dev->driver || ndns->claim)
  		return -EBUSY;

  	if (sysfs_streq(buf, "btt")) {
  		int rc = btt_claim_class(dev);
  
  		if (rc < NVDIMM_CCLASS_NONE)
  			return rc;
  		ndns->claim_class = rc;
  	} else if (sysfs_streq(buf, "pfn"))

  		ndns->claim_class = NVDIMM_CCLASS_PFN;

  	else if (sysfs_streq(buf, "dax"))

  		ndns->claim_class = NVDIMM_CCLASS_DAX;

  	else if (sysfs_streq(buf, ""))

  		ndns->claim_class = NVDIMM_CCLASS_NONE;
  	else
  		return -EINVAL;
  
  	return 0;
  }
  
  static ssize_t holder_class_store(struct device *dev,
  		struct device_attribute *attr, const char *buf, size_t len)
  {
  	struct nd_region *nd_region = to_nd_region(dev->parent);

  	int rc;

  	nd_device_lock(dev);

  	nvdimm_bus_lock(dev);
  	wait_nvdimm_bus_probe_idle(dev);
  	rc = __holder_class_store(dev, buf);
  	if (rc >= 0)
  		rc = nd_namespace_label_update(nd_region, dev);

  	dev_dbg(dev, "%s(%d)
  ", rc < 0 ? "fail " : "", rc);

  	nvdimm_bus_unlock(dev);

  	nd_device_unlock(dev);

  
  	return rc < 0 ? rc : len;
  }
  
  static ssize_t holder_class_show(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	struct nd_namespace_common *ndns = to_ndns(dev);
  	ssize_t rc;

  	nd_device_lock(dev);

  	if (ndns->claim_class == NVDIMM_CCLASS_NONE)
  		rc = sprintf(buf, "
  ");

  	else if ((ndns->claim_class == NVDIMM_CCLASS_BTT) ||
  			(ndns->claim_class == NVDIMM_CCLASS_BTT2))

  		rc = sprintf(buf, "btt
  ");
  	else if (ndns->claim_class == NVDIMM_CCLASS_PFN)
  		rc = sprintf(buf, "pfn
  ");
  	else if (ndns->claim_class == NVDIMM_CCLASS_DAX)
  		rc = sprintf(buf, "dax
  ");
  	else
  		rc = sprintf(buf, "<unknown>
  ");

  	nd_device_unlock(dev);

  
  	return rc;
  }
  static DEVICE_ATTR_RW(holder_class);

  static ssize_t mode_show(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	struct nd_namespace_common *ndns = to_ndns(dev);
  	struct device *claim;
  	char *mode;
  	ssize_t rc;

  	nd_device_lock(dev);

  	claim = ndns->claim;

  	if (claim && is_nd_btt(claim))

  		mode = "safe";

  	else if (claim && is_nd_pfn(claim))
  		mode = "memory";

  	else if (claim && is_nd_dax(claim))
  		mode = "dax";

  	else if (!claim && pmem_should_map_pages(dev))
  		mode = "memory";

  	else
  		mode = "raw";
  	rc = sprintf(buf, "%s
  ", mode);

  	nd_device_unlock(dev);

  
  	return rc;
  }
  static DEVICE_ATTR_RO(mode);

  static ssize_t force_raw_store(struct device *dev,
  		struct device_attribute *attr, const char *buf, size_t len)
  {
  	bool force_raw;
  	int rc = strtobool(buf, &force_raw);
  
  	if (rc)
  		return rc;
  
  	to_ndns(dev)->force_raw = force_raw;
  	return len;
  }
  
  static ssize_t force_raw_show(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	return sprintf(buf, "%d
  ", to_ndns(dev)->force_raw);
  }
  static DEVICE_ATTR_RW(force_raw);

  static struct attribute *nd_namespace_attributes[] = {
  	&dev_attr_nstype.attr,

  	&dev_attr_size.attr,

  	&dev_attr_mode.attr,

  	&dev_attr_uuid.attr,

  	&dev_attr_holder.attr,

  	&dev_attr_resource.attr,
  	&dev_attr_alt_name.attr,

  	&dev_attr_force_raw.attr,

  	&dev_attr_sector_size.attr,

  	&dev_attr_dpa_extents.attr,

  	&dev_attr_holder_class.attr,

  	NULL,
  };

  static umode_t namespace_visible(struct kobject *kobj,
  		struct attribute *a, int n)
  {
  	struct device *dev = container_of(kobj, struct device, kobj);

  	if (a == &dev_attr_resource.attr && is_namespace_blk(dev))
  		return 0;

  
  	if (is_namespace_pmem(dev) || is_namespace_blk(dev)) {
  		if (a == &dev_attr_size.attr)

  			return 0644;

  		return a->mode;
  	}

  	if (a == &dev_attr_nstype.attr || a == &dev_attr_size.attr
  			|| a == &dev_attr_holder.attr

  			|| a == &dev_attr_holder_class.attr

  			|| a == &dev_attr_force_raw.attr
  			|| a == &dev_attr_mode.attr)

  		return a->mode;
  
  	return 0;
  }

  static struct attribute_group nd_namespace_attribute_group = {
  	.attrs = nd_namespace_attributes,

  	.is_visible = namespace_visible,

  };
  
  static const struct attribute_group *nd_namespace_attribute_groups[] = {
  	&nd_device_attribute_group,
  	&nd_namespace_attribute_group,

  	&nd_numa_attribute_group,

  	NULL,
  };

  static const struct device_type namespace_io_device_type = {
  	.name = "nd_namespace_io",
  	.release = namespace_io_release,
  	.groups = nd_namespace_attribute_groups,
  };
  
  static const struct device_type namespace_pmem_device_type = {
  	.name = "nd_namespace_pmem",
  	.release = namespace_pmem_release,
  	.groups = nd_namespace_attribute_groups,
  };
  
  static const struct device_type namespace_blk_device_type = {
  	.name = "nd_namespace_blk",
  	.release = namespace_blk_release,
  	.groups = nd_namespace_attribute_groups,
  };
  
  static bool is_namespace_pmem(const struct device *dev)
  {
  	return dev ? dev->type == &namespace_pmem_device_type : false;
  }
  
  static bool is_namespace_blk(const struct device *dev)
  {
  	return dev ? dev->type == &namespace_blk_device_type : false;
  }
  
  static bool is_namespace_io(const struct device *dev)
  {
  	return dev ? dev->type == &namespace_io_device_type : false;
  }

  struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev)
  {
  	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;

  	resource_size_t size;

  	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 ERR_PTR(-ENODEV);
  
  		/*
  		 * Flush any in-progess probes / removals in the driver
  		 * for the raw personality of this namespace.
  		 */

  		nd_device_lock(&ndns->dev);
  		nd_device_unlock(&ndns->dev);

  		if (ndns->dev.driver) {
  			dev_dbg(&ndns->dev, "is active, can't bind %s
  ",

  					dev_name(dev));

  			return ERR_PTR(-EBUSY);
  		}

  		if (dev_WARN_ONCE(&ndns->dev, ndns->claim != dev,

  					"host (%s) vs claim (%s) mismatch
  ",

  					dev_name(dev),

  					dev_name(ndns->claim)))
  			return ERR_PTR(-ENXIO);
  	} else {
  		ndns = to_ndns(dev);
  		if (ndns->claim) {
  			dev_dbg(dev, "claimed by %s, failing probe
  ",
  				dev_name(ndns->claim));
  
  			return ERR_PTR(-ENXIO);
  		}
  	}

  	if (nvdimm_namespace_locked(ndns))
  		return ERR_PTR(-EACCES);

  	size = nvdimm_namespace_capacity(ndns);
  	if (size < ND_MIN_NAMESPACE_SIZE) {
  		dev_dbg(&ndns->dev, "%pa, too small must be at least %#x
  ",
  				&size, ND_MIN_NAMESPACE_SIZE);
  		return ERR_PTR(-ENODEV);
  	}

  	/*
  	 * Note, alignment validation for fsdax and devdax mode
  	 * namespaces happens in nd_pfn_validate() where infoblock
  	 * padding parameters can be applied.
  	 */
  	if (pmem_should_map_pages(dev)) {
  		struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
  		struct resource *res = &nsio->res;
  
  		if (!IS_ALIGNED(res->start | (res->end + 1),
  					memremap_compat_align())) {
  			dev_err(&ndns->dev, "%pr misaligned, unable to map
  ", res);
  			return ERR_PTR(-EOPNOTSUPP);
  		}
  	}

  	if (is_namespace_pmem(&ndns->dev)) {
  		struct nd_namespace_pmem *nspm;
  
  		nspm = to_nd_namespace_pmem(&ndns->dev);

  		if (uuid_not_set(nspm->uuid, &ndns->dev, __func__))

  			return ERR_PTR(-ENODEV);

  	} else if (is_namespace_blk(&ndns->dev)) {

  		struct nd_namespace_blk *nsblk;
  
  		nsblk = to_nd_namespace_blk(&ndns->dev);

  		if (uuid_not_set(nsblk->uuid, &ndns->dev, __func__))
  			return ERR_PTR(-ENODEV);
  		if (!nsblk->lbasize) {

  			dev_dbg(&ndns->dev, "sector size not set
  ");

  			return ERR_PTR(-ENODEV);
  		}

  		if (!nd_namespace_blk_validate(nsblk))
  			return ERR_PTR(-ENODEV);

  	}
  
  	return ndns;
  }
  EXPORT_SYMBOL(nvdimm_namespace_common_probe);

  int devm_namespace_enable(struct device *dev, struct nd_namespace_common *ndns,
  		resource_size_t size)
  {
  	if (is_namespace_blk(&ndns->dev))
  		return 0;
  	return devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev), size);
  }
  EXPORT_SYMBOL_GPL(devm_namespace_enable);
  
  void devm_namespace_disable(struct device *dev, struct nd_namespace_common *ndns)
  {
  	if (is_namespace_blk(&ndns->dev))
  		return;
  	devm_nsio_disable(dev, to_nd_namespace_io(&ndns->dev));
  }
  EXPORT_SYMBOL_GPL(devm_namespace_disable);

  static struct device **create_namespace_io(struct nd_region *nd_region)
  {
  	struct nd_namespace_io *nsio;
  	struct device *dev, **devs;
  	struct resource *res;
  
  	nsio = kzalloc(sizeof(*nsio), GFP_KERNEL);
  	if (!nsio)
  		return NULL;
  
  	devs = kcalloc(2, sizeof(struct device *), GFP_KERNEL);
  	if (!devs) {
  		kfree(nsio);
  		return NULL;
  	}

  	dev = &nsio->common.dev;

  	dev->type = &namespace_io_device_type;
  	dev->parent = &nd_region->dev;
  	res = &nsio->res;
  	res->name = dev_name(&nd_region->dev);
  	res->flags = IORESOURCE_MEM;
  	res->start = nd_region->ndr_start;
  	res->end = res->start + nd_region->ndr_size - 1;
  
  	devs[0] = dev;
  	return devs;
  }

  static bool has_uuid_at_pos(struct nd_region *nd_region, u8 *uuid,
  		u64 cookie, u16 pos)
  {
  	struct nd_namespace_label *found = NULL;
  	int i;
  
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[i];

  		struct nd_interleave_set *nd_set = nd_region->nd_set;
  		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);

  		struct nd_label_ent *label_ent;

  		bool found_uuid = false;

  		list_for_each_entry(label_ent, &nd_mapping->labels, list) {
  			struct nd_namespace_label *nd_label = label_ent->label;
  			u16 position, nlabel;
  			u64 isetcookie;
  
  			if (!nd_label)
  				continue;
  			isetcookie = __le64_to_cpu(nd_label->isetcookie);
  			position = __le16_to_cpu(nd_label->position);
  			nlabel = __le16_to_cpu(nd_label->nlabel);

  
  			if (isetcookie != cookie)
  				continue;
  
  			if (memcmp(nd_label->uuid, uuid, NSLABEL_UUID_LEN) != 0)
  				continue;

  			if (namespace_label_has(ndd, type_guid)
  					&& !guid_equal(&nd_set->type_guid,
  						&nd_label->type_guid)) {
  				dev_dbg(ndd->dev, "expect type_guid %pUb got %pUb
  ",

  						&nd_set->type_guid,
  						&nd_label->type_guid);

  				continue;
  			}

  			if (found_uuid) {

  				dev_dbg(ndd->dev, "duplicate entry for uuid
  ");

  				return false;
  			}
  			found_uuid = true;
  			if (nlabel != nd_region->ndr_mappings)
  				continue;
  			if (position != pos)
  				continue;
  			found = nd_label;
  			break;
  		}
  		if (found)
  			break;
  	}
  	return found != NULL;
  }
  
  static int select_pmem_id(struct nd_region *nd_region, u8 *pmem_id)
  {

  	int i;
  
  	if (!pmem_id)
  		return -ENODEV;
  
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[i];

  		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);

  		struct nd_namespace_label *nd_label = NULL;

  		u64 hw_start, hw_end, pmem_start, pmem_end;

  		struct nd_label_ent *label_ent;

  		lockdep_assert_held(&nd_mapping->lock);

  		list_for_each_entry(label_ent, &nd_mapping->labels, list) {
  			nd_label = label_ent->label;
  			if (!nd_label)
  				continue;

  			if (memcmp(nd_label->uuid, pmem_id, NSLABEL_UUID_LEN) == 0)
  				break;

  			nd_label = NULL;
  		}

  
  		if (!nd_label) {
  			WARN_ON(1);
  			return -EINVAL;
  		}

  		/*
  		 * Check that this label is compliant with the dpa
  		 * range published in NFIT
  		 */
  		hw_start = nd_mapping->start;
  		hw_end = hw_start + nd_mapping->size;

  		pmem_start = __le64_to_cpu(nd_label->dpa);
  		pmem_end = pmem_start + __le64_to_cpu(nd_label->rawsize);

  		if (pmem_start >= hw_start && pmem_start < hw_end
  				&& pmem_end <= hw_end && pmem_end > hw_start)

  			/* pass */;

  		else {
  			dev_dbg(&nd_region->dev, "%s invalid label for %pUb
  ",
  					dev_name(ndd->dev), nd_label->uuid);

  			return -EINVAL;

  		}

  		/* move recently validated label to the front of the list */
  		list_move(&label_ent->list, &nd_mapping->labels);

  	}
  	return 0;
  }
  
  /**

   * create_namespace_pmem - validate interleave set labelling, retrieve label0

   * @nd_region: region with mappings to validate

   * @nspm: target namespace to create
   * @nd_label: target pmem namespace label to evaluate

   */

  static struct device *create_namespace_pmem(struct nd_region *nd_region,

  		struct nd_namespace_index *nsindex,

  		struct nd_namespace_label *nd_label)

  {

  	u64 cookie = nd_region_interleave_set_cookie(nd_region, nsindex);

  	u64 altcookie = nd_region_interleave_set_altcookie(nd_region);

  	struct nd_label_ent *label_ent;

  	struct nd_namespace_pmem *nspm;

  	struct nd_mapping *nd_mapping;

  	resource_size_t size = 0;

  	struct resource *res;
  	struct device *dev;

  	int rc = 0;

  	u16 i;

  	if (cookie == 0) {
  		dev_dbg(&nd_region->dev, "invalid interleave-set-cookie
  ");

  		return ERR_PTR(-ENXIO);

  	}

  	if (__le64_to_cpu(nd_label->isetcookie) != cookie) {
  		dev_dbg(&nd_region->dev, "invalid cookie in label: %pUb
  ",
  				nd_label->uuid);

  		if (__le64_to_cpu(nd_label->isetcookie) != altcookie)
  			return ERR_PTR(-EAGAIN);
  
  		dev_dbg(&nd_region->dev, "valid altcookie in label: %pUb
  ",
  				nd_label->uuid);

  	}

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

  	nspm->id = -1;

  	dev = &nspm->nsio.common.dev;
  	dev->type = &namespace_pmem_device_type;
  	dev->parent = &nd_region->dev;
  	res = &nspm->nsio.res;
  	res->name = dev_name(&nd_region->dev);
  	res->flags = IORESOURCE_MEM;

  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		if (has_uuid_at_pos(nd_region, nd_label->uuid, cookie, i))
  			continue;
  		if (has_uuid_at_pos(nd_region, nd_label->uuid, altcookie, i))
  			continue;
  		break;
  	}

  	if (i < nd_region->ndr_mappings) {

  		struct nvdimm *nvdimm = nd_region->mapping[i].nvdimm;

  		/*
  		 * Give up if we don't find an instance of a uuid at each
  		 * position (from 0 to nd_region->ndr_mappings - 1), or if we
  		 * find a dimm with two instances of the same uuid.
  		 */

  		dev_err(&nd_region->dev, "%s missing label for %pUb
  ",

  				nvdimm_name(nvdimm), nd_label->uuid);

  		rc = -EINVAL;

  		goto err;

  	}

  
  	/*
  	 * Fix up each mapping's 'labels' to have the validated pmem label for
  	 * that position at labels[0], and NULL at labels[1].  In the process,
  	 * check that the namespace aligns with interleave-set.  We know
  	 * that it does not overlap with any blk namespaces by virtue of
  	 * the dimm being enabled (i.e. nd_label_reserve_dpa()
  	 * succeeded).
  	 */

  	rc = select_pmem_id(nd_region, nd_label->uuid);

  	if (rc)
  		goto err;
  
  	/* Calculate total size and populate namespace properties from label0 */
  	for (i = 0; i < nd_region->ndr_mappings; i++) {

  		struct nd_namespace_label *label0;

  		struct nvdimm_drvdata *ndd;

  
  		nd_mapping = &nd_region->mapping[i];

  		label_ent = list_first_entry_or_null(&nd_mapping->labels,
  				typeof(*label_ent), list);

  		label0 = label_ent ? label_ent->label : NULL;

  
  		if (!label0) {
  			WARN_ON(1);
  			continue;
  		}

  
  		size += __le64_to_cpu(label0->rawsize);
  		if (__le16_to_cpu(label0->position) != 0)
  			continue;
  		WARN_ON(nspm->alt_name || nspm->uuid);
  		nspm->alt_name = kmemdup((void __force *) label0->name,
  				NSLABEL_NAME_LEN, GFP_KERNEL);
  		nspm->uuid = kmemdup((void __force *) label0->uuid,
  				NSLABEL_UUID_LEN, GFP_KERNEL);

  		nspm->lbasize = __le64_to_cpu(label0->lbasize);

  		ndd = to_ndd(nd_mapping);
  		if (namespace_label_has(ndd, abstraction_guid))
  			nspm->nsio.common.claim_class
  				= to_nvdimm_cclass(&label0->abstraction_guid);

  	}
  
  	if (!nspm->alt_name || !nspm->uuid) {
  		rc = -ENOMEM;
  		goto err;
  	}

  	nd_namespace_pmem_set_resource(nd_region, nspm, size);

  	return dev;

   err:

  	namespace_pmem_release(dev);

  	switch (rc) {
  	case -EINVAL:

  		dev_dbg(&nd_region->dev, "invalid label(s)
  ");

  		break;
  	case -ENODEV:

  		dev_dbg(&nd_region->dev, "label not found
  ");

  		break;
  	default:

  		dev_dbg(&nd_region->dev, "unexpected err: %d
  ", rc);

  		break;
  	}

  	return ERR_PTR(rc);

  }

  struct resource *nsblk_add_resource(struct nd_region *nd_region,
  		struct nvdimm_drvdata *ndd, struct nd_namespace_blk *nsblk,
  		resource_size_t start)
  {
  	struct nd_label_id label_id;
  	struct resource *res;
  
  	nd_label_gen_id(&label_id, nsblk->uuid, NSLABEL_FLAG_LOCAL);
  	res = krealloc(nsblk->res,
  			sizeof(void *) * (nsblk->num_resources + 1),
  			GFP_KERNEL);
  	if (!res)
  		return NULL;
  	nsblk->res = (struct resource **) res;
  	for_each_dpa_resource(ndd, res)
  		if (strcmp(res->name, label_id.id) == 0
  				&& res->start == start) {
  			nsblk->res[nsblk->num_resources++] = res;
  			return res;
  		}
  	return NULL;
  }
  
  static struct device *nd_namespace_blk_create(struct nd_region *nd_region)
  {
  	struct nd_namespace_blk *nsblk;
  	struct device *dev;
  
  	if (!is_nd_blk(&nd_region->dev))
  		return NULL;
  
  	nsblk = kzalloc(sizeof(*nsblk), GFP_KERNEL);
  	if (!nsblk)
  		return NULL;

  	dev = &nsblk->common.dev;

  	dev->type = &namespace_blk_device_type;
  	nsblk->id = ida_simple_get(&nd_region->ns_ida, 0, 0, GFP_KERNEL);
  	if (nsblk->id < 0) {
  		kfree(nsblk);
  		return NULL;
  	}
  	dev_set_name(dev, "namespace%d.%d", nd_region->id, nsblk->id);
  	dev->parent = &nd_region->dev;

  	return &nsblk->common.dev;

  }

  static struct device *nd_namespace_pmem_create(struct nd_region *nd_region)
  {
  	struct nd_namespace_pmem *nspm;
  	struct resource *res;
  	struct device *dev;

  	if (!is_memory(&nd_region->dev))

  		return NULL;
  
  	nspm = kzalloc(sizeof(*nspm), GFP_KERNEL);
  	if (!nspm)
  		return NULL;
  
  	dev = &nspm->nsio.common.dev;
  	dev->type = &namespace_pmem_device_type;
  	dev->parent = &nd_region->dev;
  	res = &nspm->nsio.res;
  	res->name = dev_name(&nd_region->dev);
  	res->flags = IORESOURCE_MEM;
  
  	nspm->id = ida_simple_get(&nd_region->ns_ida, 0, 0, GFP_KERNEL);
  	if (nspm->id < 0) {
  		kfree(nspm);
  		return NULL;
  	}
  	dev_set_name(dev, "namespace%d.%d", nd_region->id, nspm->id);

  	nd_namespace_pmem_set_resource(nd_region, nspm, 0);
  
  	return dev;
  }
  
  void nd_region_create_ns_seed(struct nd_region *nd_region)

  {
  	WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));

  
  	if (nd_region_to_nstype(nd_region) == ND_DEVICE_NAMESPACE_IO)
  		return;
  
  	if (is_nd_blk(&nd_region->dev))
  		nd_region->ns_seed = nd_namespace_blk_create(nd_region);
  	else
  		nd_region->ns_seed = nd_namespace_pmem_create(nd_region);

  	/*
  	 * Seed creation failures are not fatal, provisioning is simply
  	 * disabled until memory becomes available
  	 */
  	if (!nd_region->ns_seed)

  		dev_err(&nd_region->dev, "failed to create %s namespace
  ",
  				is_nd_blk(&nd_region->dev) ? "blk" : "pmem");

  	else
  		nd_device_register(nd_region->ns_seed);
  }

  void nd_region_create_dax_seed(struct nd_region *nd_region)
  {
  	WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
  	nd_region->dax_seed = nd_dax_create(nd_region);
  	/*
  	 * Seed creation failures are not fatal, provisioning is simply
  	 * disabled until memory becomes available
  	 */
  	if (!nd_region->dax_seed)
  		dev_err(&nd_region->dev, "failed to create dax namespace
  ");
  }

  void nd_region_create_pfn_seed(struct nd_region *nd_region)
  {
  	WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
  	nd_region->pfn_seed = nd_pfn_create(nd_region);
  	/*
  	 * Seed creation failures are not fatal, provisioning is simply
  	 * disabled until memory becomes available
  	 */
  	if (!nd_region->pfn_seed)
  		dev_err(&nd_region->dev, "failed to create pfn namespace
  ");
  }

  void nd_region_create_btt_seed(struct nd_region *nd_region)
  {
  	WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
  	nd_region->btt_seed = nd_btt_create(nd_region);
  	/*
  	 * Seed creation failures are not fatal, provisioning is simply
  	 * disabled until memory becomes available
  	 */
  	if (!nd_region->btt_seed)
  		dev_err(&nd_region->dev, "failed to create btt namespace
  ");
  }

  static int add_namespace_resource(struct nd_region *nd_region,
  		struct nd_namespace_label *nd_label, struct device **devs,
  		int count)

  {

  	struct nd_mapping *nd_mapping = &nd_region->mapping[0];
  	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
  	int i;
  
  	for (i = 0; i < count; i++) {
  		u8 *uuid = namespace_to_uuid(devs[i]);
  		struct resource *res;
  
  		if (IS_ERR_OR_NULL(uuid)) {
  			WARN_ON(1);
  			continue;
  		}
  
  		if (memcmp(uuid, nd_label->uuid, NSLABEL_UUID_LEN) != 0)
  			continue;
  		if (is_namespace_blk(devs[i])) {
  			res = nsblk_add_resource(nd_region, ndd,
  					to_nd_namespace_blk(devs[i]),
  					__le64_to_cpu(nd_label->dpa));
  			if (!res)
  				return -ENXIO;
  			nd_dbg_dpa(nd_region, ndd, res, "%d assign
  ", count);
  		} else {
  			dev_err(&nd_region->dev,
  					"error: conflicting extents for uuid: %pUb
  ",
  					nd_label->uuid);
  			return -ENXIO;
  		}
  		break;
  	}
  
  	return i;
  }

  static struct device *create_namespace_blk(struct nd_region *nd_region,

  		struct nd_namespace_label *nd_label, int count)
  {
  
  	struct nd_mapping *nd_mapping = &nd_region->mapping[0];

  	struct nd_interleave_set *nd_set = nd_region->nd_set;

  	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);

  	struct nd_namespace_blk *nsblk;

  	char name[NSLABEL_NAME_LEN];

  	struct device *dev = NULL;
  	struct resource *res;

  	if (namespace_label_has(ndd, type_guid)) {
  		if (!guid_equal(&nd_set->type_guid, &nd_label->type_guid)) {
  			dev_dbg(ndd->dev, "expect type_guid %pUb got %pUb
  ",

  					&nd_set->type_guid,
  					&nd_label->type_guid);

  			return ERR_PTR(-EAGAIN);
  		}
  
  		if (nd_label->isetcookie != __cpu_to_le64(nd_set->cookie2)) {
  			dev_dbg(ndd->dev, "expect cookie %#llx got %#llx
  ",
  					nd_set->cookie2,
  					__le64_to_cpu(nd_label->isetcookie));
  			return ERR_PTR(-EAGAIN);
  		}

  	}

  	nsblk = kzalloc(sizeof(*nsblk), GFP_KERNEL);
  	if (!nsblk)
  		return ERR_PTR(-ENOMEM);
  	dev = &nsblk->common.dev;
  	dev->type = &namespace_blk_device_type;
  	dev->parent = &nd_region->dev;
  	nsblk->id = -1;
  	nsblk->lbasize = __le64_to_cpu(nd_label->lbasize);
  	nsblk->uuid = kmemdup(nd_label->uuid, NSLABEL_UUID_LEN,
  			GFP_KERNEL);

  	if (namespace_label_has(ndd, abstraction_guid))
  		nsblk->common.claim_class
  			= to_nvdimm_cclass(&nd_label->abstraction_guid);

  	if (!nsblk->uuid)
  		goto blk_err;
  	memcpy(name, nd_label->name, NSLABEL_NAME_LEN);

  	if (name[0]) {

  		nsblk->alt_name = kmemdup(name, NSLABEL_NAME_LEN,
  				GFP_KERNEL);

  		if (!nsblk->alt_name)
  			goto blk_err;
  	}

  	res = nsblk_add_resource(nd_region, ndd, nsblk,
  			__le64_to_cpu(nd_label->dpa));
  	if (!res)
  		goto blk_err;
  	nd_dbg_dpa(nd_region, ndd, res, "%d: assign
  ", count);
  	return dev;
   blk_err:
  	namespace_blk_release(dev);
  	return ERR_PTR(-ENXIO);
  }

  static int cmp_dpa(const void *a, const void *b)
  {
  	const struct device *dev_a = *(const struct device **) a;
  	const struct device *dev_b = *(const struct device **) b;
  	struct nd_namespace_blk *nsblk_a, *nsblk_b;
  	struct nd_namespace_pmem *nspm_a, *nspm_b;
  
  	if (is_namespace_io(dev_a))
  		return 0;
  
  	if (is_namespace_blk(dev_a)) {
  		nsblk_a = to_nd_namespace_blk(dev_a);
  		nsblk_b = to_nd_namespace_blk(dev_b);
  
  		return memcmp(&nsblk_a->res[0]->start, &nsblk_b->res[0]->start,
  				sizeof(resource_size_t));
  	}
  
  	nspm_a = to_nd_namespace_pmem(dev_a);
  	nspm_b = to_nd_namespace_pmem(dev_b);
  
  	return memcmp(&nspm_a->nsio.res.start, &nspm_b->nsio.res.start,
  			sizeof(resource_size_t));
  }

  static struct device **scan_labels(struct nd_region *nd_region)
  {

  	int i, count = 0;

  	struct device *dev, **devs = NULL;
  	struct nd_label_ent *label_ent, *e;

  	struct nd_mapping *nd_mapping = &nd_region->mapping[0];
  	resource_size_t map_end = nd_mapping->start + nd_mapping->size - 1;

  	/* "safe" because create_namespace_pmem() might list_move() label_ent */
  	list_for_each_entry_safe(label_ent, e, &nd_mapping->labels, list) {

  		struct nd_namespace_label *nd_label = label_ent->label;

  		struct device **__devs;

  		u32 flags;

  		if (!nd_label)
  			continue;
  		flags = __le32_to_cpu(nd_label->flags);

  		if (is_nd_blk(&nd_region->dev)
  				== !!(flags & NSLABEL_FLAG_LOCAL))
  			/* pass, region matches label type */;

  		else
  			continue;

  		/* skip labels that describe extents outside of the region */

  		if (__le64_to_cpu(nd_label->dpa) < nd_mapping->start ||
  		    __le64_to_cpu(nd_label->dpa) > map_end)
  				continue;

  		i = add_namespace_resource(nd_region, nd_label, devs, count);
  		if (i < 0)
  			goto err;

  		if (i < count)
  			continue;
  		__devs = kcalloc(count + 2, sizeof(dev), GFP_KERNEL);
  		if (!__devs)
  			goto err;
  		memcpy(__devs, devs, sizeof(dev) * count);
  		kfree(devs);
  		devs = __devs;

  		if (is_nd_blk(&nd_region->dev))

  			dev = create_namespace_blk(nd_region, nd_label, count);

  		else {

  			struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
  			struct nd_namespace_index *nsindex;
  
  			nsindex = to_namespace_index(ndd, ndd->ns_current);
  			dev = create_namespace_pmem(nd_region, nsindex, nd_label);

  		}

  
  		if (IS_ERR(dev)) {
  			switch (PTR_ERR(dev)) {
  			case -EAGAIN:
  				/* skip invalid labels */
  				continue;
  			case -ENODEV:
  				/* fallthrough to seed creation */
  				break;
  			default:
  				goto err;
  			}
  		} else
  			devs[count++] = dev;

  	}

  	dev_dbg(&nd_region->dev, "discovered %d %s namespace%s
  ",
  			count, is_nd_blk(&nd_region->dev)

  			? "blk" : "pmem", count == 1 ? "" : "s");

  
  	if (count == 0) {
  		/* Publish a zero-sized namespace for userspace to configure. */

  		nd_mapping_free_labels(nd_mapping);

  
  		devs = kcalloc(2, sizeof(dev), GFP_KERNEL);
  		if (!devs)
  			goto err;

  		if (is_nd_blk(&nd_region->dev)) {
  			struct nd_namespace_blk *nsblk;
  
  			nsblk = kzalloc(sizeof(*nsblk), GFP_KERNEL);
  			if (!nsblk)
  				goto err;
  			dev = &nsblk->common.dev;
  			dev->type = &namespace_blk_device_type;
  		} else {
  			struct nd_namespace_pmem *nspm;
  
  			nspm = kzalloc(sizeof(*nspm), GFP_KERNEL);
  			if (!nspm)
  				goto err;
  			dev = &nspm->nsio.common.dev;
  			dev->type = &namespace_pmem_device_type;

  			nd_namespace_pmem_set_resource(nd_region, nspm, 0);

  		}

  		dev->parent = &nd_region->dev;
  		devs[count++] = dev;

  	} else if (is_memory(&nd_region->dev)) {

  		/* clean unselected labels */
  		for (i = 0; i < nd_region->ndr_mappings; i++) {

  			struct list_head *l, *e;
  			LIST_HEAD(list);
  			int j;

  			nd_mapping = &nd_region->mapping[i];
  			if (list_empty(&nd_mapping->labels)) {
  				WARN_ON(1);
  				continue;
  			}

  
  			j = count;
  			list_for_each_safe(l, e, &nd_mapping->labels) {
  				if (!j--)
  					break;
  				list_move_tail(l, &list);
  			}

  			nd_mapping_free_labels(nd_mapping);

  			list_splice_init(&list, &nd_mapping->labels);

  		}

  	}

  	if (count > 1)
  		sort(devs, count, sizeof(struct device *), cmp_dpa, NULL);

  	return devs;

   err:

  	if (devs) {
  		for (i = 0; devs[i]; i++)
  			if (is_nd_blk(&nd_region->dev))
  				namespace_blk_release(devs[i]);
  			else
  				namespace_pmem_release(devs[i]);
  		kfree(devs);
  	}

  	return NULL;
  }

  static struct device **create_namespaces(struct nd_region *nd_region)

  {

  	struct nd_mapping *nd_mapping;

  	struct device **devs;

  	int i;

  
  	if (nd_region->ndr_mappings == 0)
  		return NULL;

  	/* lock down all mappings while we scan labels */
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		nd_mapping = &nd_region->mapping[i];
  		mutex_lock_nested(&nd_mapping->lock, i);
  	}
  
  	devs = scan_labels(nd_region);
  
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		int reverse = nd_region->ndr_mappings - 1 - i;
  
  		nd_mapping = &nd_region->mapping[reverse];
  		mutex_unlock(&nd_mapping->lock);
  	}

  
  	return devs;
  }

  static void deactivate_labels(void *region)
  {
  	struct nd_region *nd_region = region;
  	int i;
  
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
  		struct nvdimm_drvdata *ndd = nd_mapping->ndd;
  		struct nvdimm *nvdimm = nd_mapping->nvdimm;
  
  		mutex_lock(&nd_mapping->lock);
  		nd_mapping_free_labels(nd_mapping);
  		mutex_unlock(&nd_mapping->lock);
  
  		put_ndd(ndd);
  		nd_mapping->ndd = NULL;
  		if (ndd)
  			atomic_dec(&nvdimm->busy);
  	}
  }

  static int init_active_labels(struct nd_region *nd_region)
  {
  	int i;
  
  	for (i = 0; i < nd_region->ndr_mappings; i++) {
  		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
  		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
  		struct nvdimm *nvdimm = nd_mapping->nvdimm;

  		struct nd_label_ent *label_ent;

  		int count, j;
  
  		/*

  		 * If the dimm is disabled then we may need to prevent
  		 * the region from being activated.

  		 */
  		if (!ndd) {

  			if (test_bit(NDD_LOCKED, &nvdimm->flags))
  				/* fail, label data may be unreadable */;

  			else if (test_bit(NDD_LABELING, &nvdimm->flags))

  				/* fail, labels needed to disambiguate dpa */;
  			else

  				return 0;

  
  			dev_err(&nd_region->dev, "%s: is %s, failing probe
  ",
  					dev_name(&nd_mapping->nvdimm->dev),
  					test_bit(NDD_LOCKED, &nvdimm->flags)
  					? "locked" : "disabled");

  			return -ENXIO;
  		}
  		nd_mapping->ndd = ndd;
  		atomic_inc(&nvdimm->busy);
  		get_ndd(ndd);
  
  		count = nd_label_active_count(ndd);

  		dev_dbg(ndd->dev, "count: %d
  ", count);

  		if (!count)
  			continue;

  		for (j = 0; j < count; j++) {
  			struct nd_namespace_label *label;

  			label_ent = kzalloc(sizeof(*label_ent), GFP_KERNEL);
  			if (!label_ent)
  				break;

  			label = nd_label_active(ndd, j);

  			if (test_bit(NDD_NOBLK, &nvdimm->flags)) {
  				u32 flags = __le32_to_cpu(label->flags);
  
  				flags &= ~NSLABEL_FLAG_LOCAL;
  				label->flags = __cpu_to_le32(flags);
  			}

  			label_ent->label = label;
  
  			mutex_lock(&nd_mapping->lock);
  			list_add_tail(&label_ent->list, &nd_mapping->labels);
  			mutex_unlock(&nd_mapping->lock);

  		}

  		if (j < count)
  			break;
  	}

  	if (i < nd_region->ndr_mappings) {
  		deactivate_labels(nd_region);

  		return -ENOMEM;

  	}

  	return devm_add_action_or_reset(&nd_region->dev, deactivate_labels,
  			nd_region);

  }

  int nd_region_register_namespaces(struct nd_region *nd_region, int *err)
  {
  	struct device **devs = NULL;

  	int i, rc = 0, type;

  
  	*err = 0;

  	nvdimm_bus_lock(&nd_region->dev);
  	rc = init_active_labels(nd_region);
  	if (rc) {
  		nvdimm_bus_unlock(&nd_region->dev);
  		return rc;
  	}
  
  	type = nd_region_to_nstype(nd_region);
  	switch (type) {

  	case ND_DEVICE_NAMESPACE_IO:
  		devs = create_namespace_io(nd_region);
  		break;

  	case ND_DEVICE_NAMESPACE_PMEM:

  	case ND_DEVICE_NAMESPACE_BLK:

  		devs = create_namespaces(nd_region);

  		break;

  	default:
  		break;
  	}

  	nvdimm_bus_unlock(&nd_region->dev);

  
  	if (!devs)
  		return -ENODEV;
  
  	for (i = 0; devs[i]; i++) {
  		struct device *dev = devs[i];

  		int id;

  		if (type == ND_DEVICE_NAMESPACE_BLK) {
  			struct nd_namespace_blk *nsblk;
  
  			nsblk = to_nd_namespace_blk(dev);
  			id = ida_simple_get(&nd_region->ns_ida, 0, 0,
  					GFP_KERNEL);
  			nsblk->id = id;

  		} else if (type == ND_DEVICE_NAMESPACE_PMEM) {
  			struct nd_namespace_pmem *nspm;
  
  			nspm = to_nd_namespace_pmem(dev);
  			id = ida_simple_get(&nd_region->ns_ida, 0, 0,
  					GFP_KERNEL);
  			nspm->id = id;

  		} else
  			id = i;
  
  		if (id < 0)
  			break;
  		dev_set_name(dev, "namespace%d.%d", nd_region->id, id);

  		nd_device_register(dev);
  	}

  	if (i)
  		nd_region->ns_seed = devs[0];
  
  	if (devs[i]) {
  		int j;
  
  		for (j = i; devs[j]; j++) {
  			struct device *dev = devs[j];
  
  			device_initialize(dev);
  			put_device(dev);
  		}
  		*err = j - i;
  		/*
  		 * All of the namespaces we tried to register failed, so
  		 * fail region activation.
  		 */
  		if (*err == 0)
  			rc = -ENODEV;
  	}

  	kfree(devs);

  	if (rc == -ENODEV)
  		return rc;

  	return i;
  }