[linux-block.git] / drivers / nvdimm / btt_devs.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
 */
#include <linux/blkdev.h>
#include <linux/device.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include "nd-core.h"
#include "btt.h"
#include "nd.h"

static void nd_btt_release(struct device *dev)
{
	struct nd_region *nd_region = to_nd_region(dev->parent);
	struct nd_btt *nd_btt = to_nd_btt(dev);

	dev_dbg(dev, "trace\n");
	nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
	kfree(nd_btt->uuid);
	kfree(nd_btt);
}

struct nd_btt *to_nd_btt(struct device *dev)
{
	struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);

	WARN_ON(!is_nd_btt(dev));
	return nd_btt;
}
EXPORT_SYMBOL(to_nd_btt);

static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
	4096, 4104, 4160, 4224, 0 };

static ssize_t sector_size_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct nd_btt *nd_btt = to_nd_btt(dev);

	return nd_size_select_show(nd_btt->lbasize, btt_lbasize_supported, buf);
}

static ssize_t sector_size_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t len)
{
	struct nd_btt *nd_btt = to_nd_btt(dev);
	ssize_t rc;

	nd_device_lock(dev);
	nvdimm_bus_lock(dev);
	rc = nd_size_select_store(dev, buf, &nd_btt->lbasize,
			btt_lbasize_supported);
	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
			buf[len - 1] == '\n' ? "" : "\n");
	nvdimm_bus_unlock(dev);
	nd_device_unlock(dev);

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

static ssize_t uuid_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct nd_btt *nd_btt = to_nd_btt(dev);

	if (nd_btt->uuid)
		return sprintf(buf, "%pUb\n", nd_btt->uuid);
	return sprintf(buf, "\n");
}

static ssize_t uuid_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t len)
{
	struct nd_btt *nd_btt = to_nd_btt(dev);
	ssize_t rc;

	nd_device_lock(dev);
	rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
			buf[len - 1] == '\n' ? "" : "\n");
	nd_device_unlock(dev);

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

static ssize_t namespace_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct nd_btt *nd_btt = to_nd_btt(dev);
	ssize_t rc;

	nvdimm_bus_lock(dev);
	rc = sprintf(buf, "%s\n", nd_btt->ndns
			? dev_name(&nd_btt->ndns->dev) : "");
	nvdimm_bus_unlock(dev);
	return rc;
}

static ssize_t namespace_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t len)
{
	struct nd_btt *nd_btt = to_nd_btt(dev);
	ssize_t rc;

	nd_device_lock(dev);
	nvdimm_bus_lock(dev);
	rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
			buf[len - 1] == '\n' ? "" : "\n");
	nvdimm_bus_unlock(dev);
	nd_device_unlock(dev);

	return rc;
}
static DEVICE_ATTR_RW(namespace);

static ssize_t size_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct nd_btt *nd_btt = to_nd_btt(dev);
	ssize_t rc;

	nd_device_lock(dev);
	if (dev->driver)
		rc = sprintf(buf, "%llu\n", nd_btt->size);
	else {
		/* no size to convey if the btt instance is disabled */
		rc = -ENXIO;
	}
	nd_device_unlock(dev);

	return rc;
}
static DEVICE_ATTR_RO(size);

static ssize_t log_zero_flags_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "Y\n");
}
static DEVICE_ATTR_RO(log_zero_flags);

static struct attribute *nd_btt_attributes[] = {
	&dev_attr_sector_size.attr,
	&dev_attr_namespace.attr,
	&dev_attr_uuid.attr,
	&dev_attr_size.attr,
	&dev_attr_log_zero_flags.attr,
	NULL,
};

static struct attribute_group nd_btt_attribute_group = {
	.attrs = nd_btt_attributes,
};

static const struct attribute_group *nd_btt_attribute_groups[] = {
	&nd_btt_attribute_group,
	&nd_device_attribute_group,
	&nd_numa_attribute_group,
	NULL,
};

static const struct device_type nd_btt_device_type = {
	.name = "nd_btt",
	.release = nd_btt_release,
	.groups = nd_btt_attribute_groups,
};

bool is_nd_btt(struct device *dev)
{
	return dev->type == &nd_btt_device_type;
}
EXPORT_SYMBOL(is_nd_btt);

static struct device *__nd_btt_create(struct nd_region *nd_region,
				      unsigned long lbasize, uuid_t *uuid,
				      struct nd_namespace_common *ndns)
{
	struct nd_btt *nd_btt;
	struct device *dev;

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

	nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL);
	if (nd_btt->id < 0)
		goto out_nd_btt;

	nd_btt->lbasize = lbasize;
	if (uuid) {
		uuid = kmemdup(uuid, 16, GFP_KERNEL);
		if (!uuid)
			goto out_put_id;
	}
	nd_btt->uuid = uuid;
	dev = &nd_btt->dev;
	dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
	dev->parent = &nd_region->dev;
	dev->type = &nd_btt_device_type;
	device_initialize(&nd_btt->dev);
	if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
		dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
				dev_name(ndns->claim));
		put_device(dev);
		return NULL;
	}
	return dev;

out_put_id:
	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);

out_nd_btt:
	kfree(nd_btt);
	return NULL;
}

struct device *nd_btt_create(struct nd_region *nd_region)
{
	struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);

	__nd_device_register(dev);
	return dev;
}

/**
 * nd_btt_arena_is_valid - check if the metadata layout is valid
 * @nd_btt:	device with BTT geometry and backing device info
 * @super:	pointer to the arena's info block being tested
 *
 * Check consistency of the btt info block with itself by validating
 * the checksum, and with the parent namespace by verifying the
 * parent_uuid contained in the info block with the one supplied in.
 *
 * Returns:
 * false for an invalid info block, true for a valid one
 */
bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
{
	const uuid_t *ns_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
	uuid_t parent_uuid;
	u64 checksum;

	if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
		return false;

	import_uuid(&parent_uuid, super->parent_uuid);
	if (!uuid_is_null(&parent_uuid))
		if (!uuid_equal(&parent_uuid, ns_uuid))
			return false;

	checksum = le64_to_cpu(super->checksum);
	super->checksum = 0;
	if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
		return false;
	super->checksum = cpu_to_le64(checksum);

	/* TODO: figure out action for this */
	if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
		dev_info(&nd_btt->dev, "Found arena with an error flag\n");

	return true;
}
EXPORT_SYMBOL(nd_btt_arena_is_valid);

int nd_btt_version(struct nd_btt *nd_btt, struct nd_namespace_common *ndns,
		struct btt_sb *btt_sb)
{
	if (ndns->claim_class == NVDIMM_CCLASS_BTT2) {
		/* Probe/setup for BTT v2.0 */
		nd_btt->initial_offset = 0;
		nd_btt->version_major = 2;
		nd_btt->version_minor = 0;
		if (nvdimm_read_bytes(ndns, 0, btt_sb, sizeof(*btt_sb), 0))
			return -ENXIO;
		if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
			return -ENODEV;
		if ((le16_to_cpu(btt_sb->version_major) != 2) ||
				(le16_to_cpu(btt_sb->version_minor) != 0))
			return -ENODEV;
	} else {
		/*
		 * Probe/setup for BTT v1.1 (NVDIMM_CCLASS_NONE or
		 * NVDIMM_CCLASS_BTT)
		 */
		nd_btt->initial_offset = SZ_4K;
		nd_btt->version_major = 1;
		nd_btt->version_minor = 1;
		if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb), 0))
			return -ENXIO;
		if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
			return -ENODEV;
		if ((le16_to_cpu(btt_sb->version_major) != 1) ||
				(le16_to_cpu(btt_sb->version_minor) != 1))
			return -ENODEV;
	}
	return 0;
}
EXPORT_SYMBOL(nd_btt_version);

static int __nd_btt_probe(struct nd_btt *nd_btt,
		struct nd_namespace_common *ndns, struct btt_sb *btt_sb)
{
	int rc;

	if (!btt_sb || !ndns || !nd_btt)
		return -ENODEV;

	if (nvdimm_namespace_capacity(ndns) < SZ_16M)
		return -ENXIO;

	rc = nd_btt_version(nd_btt, ndns, btt_sb);
	if (rc < 0)
		return rc;

	nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
	nd_btt->uuid = kmemdup(&btt_sb->uuid, sizeof(uuid_t), GFP_KERNEL);
	if (!nd_btt->uuid)
		return -ENOMEM;

	__nd_device_register(&nd_btt->dev);

	return 0;
}

int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns)
{
	int rc;
	struct device *btt_dev;
	struct btt_sb *btt_sb;
	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);

	if (ndns->force_raw)
		return -ENODEV;

	switch (ndns->claim_class) {
	case NVDIMM_CCLASS_NONE:
	case NVDIMM_CCLASS_BTT:
	case NVDIMM_CCLASS_BTT2:
		break;
	default:
		return -ENODEV;
	}

	nvdimm_bus_lock(&ndns->dev);
	btt_dev = __nd_btt_create(nd_region, 0, NULL, ndns);
	nvdimm_bus_unlock(&ndns->dev);
	if (!btt_dev)
		return -ENOMEM;
	btt_sb = devm_kzalloc(dev, sizeof(*btt_sb), GFP_KERNEL);
	rc = __nd_btt_probe(to_nd_btt(btt_dev), ndns, btt_sb);
	dev_dbg(dev, "btt: %s\n", rc == 0 ? dev_name(btt_dev) : "<none>");
	if (rc < 0) {
		struct nd_btt *nd_btt = to_nd_btt(btt_dev);

		nd_detach_ndns(btt_dev, &nd_btt->ndns);
		put_device(btt_dev);
	}

	return rc;
}
EXPORT_SYMBOL(nd_btt_probe);
Commit	Line	Data
5b497af4	1	// SPDX-License-Identifier: GPL-2.0-only
8c2f7e86 DW	2	/*
8c2f7e86 DW	3	* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
8c2f7e86 DW	4	*/
	5	#include <linux/blkdev.h>
	6	#include <linux/device.h>
8c2f7e86 DW	7	#include <linux/sizes.h>
	8	#include <linux/slab.h>
	9	#include <linux/fs.h>
	10	#include <linux/mm.h>
	11	#include "nd-core.h"
	12	#include "btt.h"
	13	#include "nd.h"
	14
8c2f7e86 DW	15	static void nd_btt_release(struct device *dev)
	16	{
	17	struct nd_region *nd_region = to_nd_region(dev->parent);
	18	struct nd_btt *nd_btt = to_nd_btt(dev);
	19
426824d6	20	dev_dbg(dev, "trace\n");
e1455744	21	nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
8c2f7e86 DW	22	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
	23	kfree(nd_btt->uuid);
	24	kfree(nd_btt);
	25	}
	26
8c2f7e86 DW	27	struct nd_btt to_nd_btt(struct device dev)
	28	{
	29	struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
	30
	31	WARN_ON(!is_nd_btt(dev));
	32	return nd_btt;
	33	}
	34	EXPORT_SYMBOL(to_nd_btt);
	35
41cd8b70 VV	36	static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
41cd8b70 VV	37	4096, 4104, 4160, 4224, 0 };
8c2f7e86 DW	38
	39	static ssize_t sector_size_show(struct device *dev,
	40	struct device_attribute attr, char buf)
	41	{
	42	struct nd_btt *nd_btt = to_nd_btt(dev);
	43
b2c48f9f	44	return nd_size_select_show(nd_btt->lbasize, btt_lbasize_supported, buf);
8c2f7e86 DW	45	}
	46
	47	static ssize_t sector_size_store(struct device *dev,
	48	struct device_attribute attr, const char buf, size_t len)
	49	{
	50	struct nd_btt *nd_btt = to_nd_btt(dev);
	51	ssize_t rc;
	52
87a30e1f	53	nd_device_lock(dev);
8c2f7e86	54	nvdimm_bus_lock(dev);
b2c48f9f	55	rc = nd_size_select_store(dev, buf, &nd_btt->lbasize,
8c2f7e86	56	btt_lbasize_supported);
426824d6 DW	57	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
426824d6 DW	58	buf[len - 1] == '\n' ? "" : "\n");
8c2f7e86	59	nvdimm_bus_unlock(dev);
87a30e1f	60	nd_device_unlock(dev);
8c2f7e86 DW	61
	62	return rc ? rc : len;
	63	}
	64	static DEVICE_ATTR_RW(sector_size);
	65
	66	static ssize_t uuid_show(struct device *dev,
	67	struct device_attribute attr, char buf)
	68	{
	69	struct nd_btt *nd_btt = to_nd_btt(dev);
	70
	71	if (nd_btt->uuid)
	72	return sprintf(buf, "%pUb\n", nd_btt->uuid);
	73	return sprintf(buf, "\n");
	74	}
	75
	76	static ssize_t uuid_store(struct device *dev,
	77	struct device_attribute attr, const char buf, size_t len)
	78	{
	79	struct nd_btt *nd_btt = to_nd_btt(dev);
	80	ssize_t rc;
	81
87a30e1f	82	nd_device_lock(dev);
8c2f7e86	83	rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
426824d6 DW	84	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
426824d6 DW	85	buf[len - 1] == '\n' ? "" : "\n");
87a30e1f	86	nd_device_unlock(dev);
8c2f7e86 DW	87
	88	return rc ? rc : len;
	89	}
	90	static DEVICE_ATTR_RW(uuid);
	91
	92	static ssize_t namespace_show(struct device *dev,
	93	struct device_attribute attr, char buf)
	94	{
	95	struct nd_btt *nd_btt = to_nd_btt(dev);
	96	ssize_t rc;
	97
	98	nvdimm_bus_lock(dev);
	99	rc = sprintf(buf, "%s\n", nd_btt->ndns
	100	? dev_name(&nd_btt->ndns->dev) : "");
	101	nvdimm_bus_unlock(dev);
	102	return rc;
	103	}
	104
8c2f7e86 DW	105	static ssize_t namespace_store(struct device *dev,
	106	struct device_attribute attr, const char buf, size_t len)
	107	{
e1455744	108	struct nd_btt *nd_btt = to_nd_btt(dev);
8c2f7e86 DW	109	ssize_t rc;
8c2f7e86 DW	110
87a30e1f	111	nd_device_lock(dev);
4be9c1fc	112	nvdimm_bus_lock(dev);
e1455744	113	rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
426824d6 DW	114	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
426824d6 DW	115	buf[len - 1] == '\n' ? "" : "\n");
8c2f7e86	116	nvdimm_bus_unlock(dev);
87a30e1f	117	nd_device_unlock(dev);
8c2f7e86 DW	118
	119	return rc;
	120	}
	121	static DEVICE_ATTR_RW(namespace);
	122
abe8b4e3 VV	123	static ssize_t size_show(struct device *dev,
	124	struct device_attribute attr, char buf)
	125	{
	126	struct nd_btt *nd_btt = to_nd_btt(dev);
	127	ssize_t rc;
	128
87a30e1f	129	nd_device_lock(dev);
abe8b4e3 VV	130	if (dev->driver)
	131	rc = sprintf(buf, "%llu\n", nd_btt->size);
	132	else {
	133	/* no size to convey if the btt instance is disabled */
	134	rc = -ENXIO;
	135	}
87a30e1f	136	nd_device_unlock(dev);
abe8b4e3 VV	137
	138	return rc;
	139	}
	140	static DEVICE_ATTR_RO(size);
	141
9dedc73a VV	142	static ssize_t log_zero_flags_show(struct device *dev,
	143	struct device_attribute attr, char buf)
	144	{
	145	return sprintf(buf, "Y\n");
	146	}
	147	static DEVICE_ATTR_RO(log_zero_flags);
	148
8c2f7e86 DW	149	static struct attribute *nd_btt_attributes[] = {
	150	&dev_attr_sector_size.attr,
	151	&dev_attr_namespace.attr,
	152	&dev_attr_uuid.attr,
abe8b4e3	153	&dev_attr_size.attr,
9dedc73a	154	&dev_attr_log_zero_flags.attr,
8c2f7e86 DW	155	NULL,
	156	};
	157
	158	static struct attribute_group nd_btt_attribute_group = {
	159	.attrs = nd_btt_attributes,
	160	};
	161
	162	static const struct attribute_group *nd_btt_attribute_groups[] = {
	163	&nd_btt_attribute_group,
	164	&nd_device_attribute_group,
74ae66c3	165	&nd_numa_attribute_group,
8c2f7e86 DW	166	NULL,
	167	};
	168
78c81cc8 DW	169	static const struct device_type nd_btt_device_type = {
	170	.name = "nd_btt",
	171	.release = nd_btt_release,
	172	.groups = nd_btt_attribute_groups,
	173	};
	174
	175	bool is_nd_btt(struct device *dev)
	176	{
	177	return dev->type == &nd_btt_device_type;
	178	}
	179	EXPORT_SYMBOL(is_nd_btt);
	180
8c2f7e86	181	static struct device __nd_btt_create(struct nd_region nd_region,
d1c6e08e DW	182	unsigned long lbasize, uuid_t *uuid,
d1c6e08e DW	183	struct nd_namespace_common *ndns)
8c2f7e86 DW	184	{
	185	struct nd_btt *nd_btt;
	186	struct device *dev;
	187
	188	nd_btt = kzalloc(sizeof(*nd_btt), GFP_KERNEL);
	189	if (!nd_btt)
	190	return NULL;
	191
	192	nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL);
486fa92d AP	193	if (nd_btt->id < 0)
486fa92d AP	194	goto out_nd_btt;
8c2f7e86 DW	195
8c2f7e86 DW	196	nd_btt->lbasize = lbasize;
486fa92d	197	if (uuid) {
8c2f7e86	198	uuid = kmemdup(uuid, 16, GFP_KERNEL);
486fa92d AP	199	if (!uuid)
	200	goto out_put_id;
	201	}
8c2f7e86 DW	202	nd_btt->uuid = uuid;
	203	dev = &nd_btt->dev;
	204	dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
	205	dev->parent = &nd_region->dev;
	206	dev->type = &nd_btt_device_type;
8c2f7e86	207	device_initialize(&nd_btt->dev);
e1455744	208	if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
426824d6 DW	209	dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
426824d6 DW	210	dev_name(ndns->claim));
8c2f7e86 DW	211	put_device(dev);
	212	return NULL;
	213	}
	214	return dev;
486fa92d AP	215
	216	out_put_id:
	217	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
	218
	219	out_nd_btt:
	220	kfree(nd_btt);
	221	return NULL;
8c2f7e86 DW	222	}
	223
	224	struct device nd_btt_create(struct nd_region nd_region)
	225	{
	226	struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);
	227
d4c5725d	228	__nd_device_register(dev);
8c2f7e86 DW	229	return dev;
	230	}
	231
ab45e763 VV	232	/**
	233	* nd_btt_arena_is_valid - check if the metadata layout is valid
	234	* @nd_btt: device with BTT geometry and backing device info
	235	* @super: pointer to the arena's info block being tested
	236	*
	237	* Check consistency of the btt info block with itself by validating
6ec68954 VV	238	* the checksum, and with the parent namespace by verifying the
6ec68954 VV	239	* parent_uuid contained in the info block with the one supplied in.
ab45e763 VV	240	*
	241	* Returns:
	242	* false for an invalid info block, true for a valid one
	243	*/
	244	bool nd_btt_arena_is_valid(struct nd_btt nd_btt, struct btt_sb super)
	245	{
d1c6e08e DW	246	const uuid_t *ns_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
d1c6e08e DW	247	uuid_t parent_uuid;
ab45e763 VV	248	u64 checksum;
	249
	250	if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
	251	return false;
	252
d1c6e08e DW	253	import_uuid(&parent_uuid, super->parent_uuid);
	254	if (!uuid_is_null(&parent_uuid))
	255	if (!uuid_equal(&parent_uuid, ns_uuid))
6ec68954 VV	256	return false;
6ec68954 VV	257
ab45e763 VV	258	checksum = le64_to_cpu(super->checksum);
ab45e763 VV	259	super->checksum = 0;
e1455744	260	if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
ab45e763 VV	261	return false;
	262	super->checksum = cpu_to_le64(checksum);
	263
	264	/* TODO: figure out action for this */
	265	if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
	266	dev_info(&nd_btt->dev, "Found arena with an error flag\n");
	267
	268	return true;
	269	}
	270	EXPORT_SYMBOL(nd_btt_arena_is_valid);
	271
14e49454 VV	272	int nd_btt_version(struct nd_btt nd_btt, struct nd_namespace_common ndns,
	273	struct btt_sb *btt_sb)
	274	{
	275	if (ndns->claim_class == NVDIMM_CCLASS_BTT2) {
	276	/* Probe/setup for BTT v2.0 */
	277	nd_btt->initial_offset = 0;
	278	nd_btt->version_major = 2;
	279	nd_btt->version_minor = 0;
	280	if (nvdimm_read_bytes(ndns, 0, btt_sb, sizeof(*btt_sb), 0))
	281	return -ENXIO;
	282	if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
	283	return -ENODEV;
	284	if ((le16_to_cpu(btt_sb->version_major) != 2) \|\|
	285	(le16_to_cpu(btt_sb->version_minor) != 0))
	286	return -ENODEV;
	287	} else {
	288	/*
	289	* Probe/setup for BTT v1.1 (NVDIMM_CCLASS_NONE or
	290	* NVDIMM_CCLASS_BTT)
	291	*/
	292	nd_btt->initial_offset = SZ_4K;
	293	nd_btt->version_major = 1;
	294	nd_btt->version_minor = 1;
	295	if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb), 0))
	296	return -ENXIO;
	297	if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
	298	return -ENODEV;
	299	if ((le16_to_cpu(btt_sb->version_major) != 1) \|\|
	300	(le16_to_cpu(btt_sb->version_minor) != 1))
	301	return -ENODEV;
	302	}
	303	return 0;
	304	}
	305	EXPORT_SYMBOL(nd_btt_version);
	306
8c2f7e86 DW	307	static int __nd_btt_probe(struct nd_btt *nd_btt,
	308	struct nd_namespace_common ndns, struct btt_sb btt_sb)
	309	{
14e49454 VV	310	int rc;
14e49454 VV	311
8c2f7e86 DW	312	if (!btt_sb \|\| !ndns \|\| !nd_btt)
	313	return -ENODEV;
	314
8c2f7e86 DW	315	if (nvdimm_namespace_capacity(ndns) < SZ_16M)
	316	return -ENXIO;
	317
14e49454 VV	318	rc = nd_btt_version(nd_btt, ndns, btt_sb);
	319	if (rc < 0)
	320	return rc;
8c2f7e86 DW	321
8c2f7e86 DW	322	nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
d1c6e08e	323	nd_btt->uuid = kmemdup(&btt_sb->uuid, sizeof(uuid_t), GFP_KERNEL);
8c2f7e86 DW	324	if (!nd_btt->uuid)
	325	return -ENOMEM;
	326
	327	__nd_device_register(&nd_btt->dev);
	328
	329	return 0;
	330	}
	331
200c79da	332	int nd_btt_probe(struct device dev, struct nd_namespace_common ndns)
8c2f7e86 DW	333	{
8c2f7e86 DW	334	int rc;
e32bc729	335	struct device *btt_dev;
8c2f7e86 DW	336	struct btt_sb *btt_sb;
	337	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
	338
	339	if (ndns->force_raw)
	340	return -ENODEV;
	341
b3fde74e DW	342	switch (ndns->claim_class) {
	343	case NVDIMM_CCLASS_NONE:
	344	case NVDIMM_CCLASS_BTT:
14e49454	345	case NVDIMM_CCLASS_BTT2:
b3fde74e DW	346	break;
	347	default:
	348	return -ENODEV;
	349	}
	350
8c2f7e86	351	nvdimm_bus_lock(&ndns->dev);
e32bc729	352	btt_dev = __nd_btt_create(nd_region, 0, NULL, ndns);
8c2f7e86	353	nvdimm_bus_unlock(&ndns->dev);
e32bc729	354	if (!btt_dev)
8c2f7e86	355	return -ENOMEM;
e32bc729 DW	356	btt_sb = devm_kzalloc(dev, sizeof(*btt_sb), GFP_KERNEL);
e32bc729 DW	357	rc = __nd_btt_probe(to_nd_btt(btt_dev), ndns, btt_sb);
426824d6	358	dev_dbg(dev, "btt: %s\n", rc == 0 ? dev_name(btt_dev) : "<none>");
8c2f7e86	359	if (rc < 0) {
e32bc729	360	struct nd_btt *nd_btt = to_nd_btt(btt_dev);
e1455744	361
452bae0a	362	nd_detach_ndns(btt_dev, &nd_btt->ndns);
e32bc729	363	put_device(btt_dev);
8c2f7e86 DW	364	}
	365
	366	return rc;
	367	}
	368	EXPORT_SYMBOL(nd_btt_probe);