[mirror_ubuntu-jammy-kernel.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/genhd.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, u8 *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 u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
	u64 checksum;

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

	if (!guid_is_null((guid_t *)&super->parent_uuid))
		if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
			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, 16, 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>
	7	#include <linux/genhd.h>
	8	#include <linux/sizes.h>
	9	#include <linux/slab.h>
	10	#include <linux/fs.h>
	11	#include <linux/mm.h>
	12	#include "nd-core.h"
	13	#include "btt.h"
	14	#include "nd.h"
	15
8c2f7e86 DW	16	static void nd_btt_release(struct device *dev)
	17	{
	18	struct nd_region *nd_region = to_nd_region(dev->parent);
	19	struct nd_btt *nd_btt = to_nd_btt(dev);
	20
426824d6	21	dev_dbg(dev, "trace\n");
e1455744	22	nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
8c2f7e86 DW	23	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
	24	kfree(nd_btt->uuid);
	25	kfree(nd_btt);
	26	}
	27
8c2f7e86 DW	28	struct nd_btt to_nd_btt(struct device dev)
	29	{
	30	struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
	31
	32	WARN_ON(!is_nd_btt(dev));
	33	return nd_btt;
	34	}
	35	EXPORT_SYMBOL(to_nd_btt);
	36
41cd8b70 VV	37	static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
41cd8b70 VV	38	4096, 4104, 4160, 4224, 0 };
8c2f7e86 DW	39
	40	static ssize_t sector_size_show(struct device *dev,
	41	struct device_attribute attr, char buf)
	42	{
	43	struct nd_btt *nd_btt = to_nd_btt(dev);
	44
b2c48f9f	45	return nd_size_select_show(nd_btt->lbasize, btt_lbasize_supported, buf);
8c2f7e86 DW	46	}
	47
	48	static ssize_t sector_size_store(struct device *dev,
	49	struct device_attribute attr, const char buf, size_t len)
	50	{
	51	struct nd_btt *nd_btt = to_nd_btt(dev);
	52	ssize_t rc;
	53
87a30e1f	54	nd_device_lock(dev);
8c2f7e86	55	nvdimm_bus_lock(dev);
b2c48f9f	56	rc = nd_size_select_store(dev, buf, &nd_btt->lbasize,
8c2f7e86	57	btt_lbasize_supported);
426824d6 DW	58	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
426824d6 DW	59	buf[len - 1] == '\n' ? "" : "\n");
8c2f7e86	60	nvdimm_bus_unlock(dev);
87a30e1f	61	nd_device_unlock(dev);
8c2f7e86 DW	62
	63	return rc ? rc : len;
	64	}
	65	static DEVICE_ATTR_RW(sector_size);
	66
	67	static ssize_t uuid_show(struct device *dev,
	68	struct device_attribute attr, char buf)
	69	{
	70	struct nd_btt *nd_btt = to_nd_btt(dev);
	71
	72	if (nd_btt->uuid)
	73	return sprintf(buf, "%pUb\n", nd_btt->uuid);
	74	return sprintf(buf, "\n");
	75	}
	76
	77	static ssize_t uuid_store(struct device *dev,
	78	struct device_attribute attr, const char buf, size_t len)
	79	{
	80	struct nd_btt *nd_btt = to_nd_btt(dev);
	81	ssize_t rc;
	82
87a30e1f	83	nd_device_lock(dev);
8c2f7e86	84	rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
426824d6 DW	85	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
426824d6 DW	86	buf[len - 1] == '\n' ? "" : "\n");
87a30e1f	87	nd_device_unlock(dev);
8c2f7e86 DW	88
	89	return rc ? rc : len;
	90	}
	91	static DEVICE_ATTR_RW(uuid);
	92
	93	static ssize_t namespace_show(struct device *dev,
	94	struct device_attribute attr, char buf)
	95	{
	96	struct nd_btt *nd_btt = to_nd_btt(dev);
	97	ssize_t rc;
	98
	99	nvdimm_bus_lock(dev);
	100	rc = sprintf(buf, "%s\n", nd_btt->ndns
	101	? dev_name(&nd_btt->ndns->dev) : "");
	102	nvdimm_bus_unlock(dev);
	103	return rc;
	104	}
	105
8c2f7e86 DW	106	static ssize_t namespace_store(struct device *dev,
	107	struct device_attribute attr, const char buf, size_t len)
	108	{
e1455744	109	struct nd_btt *nd_btt = to_nd_btt(dev);
8c2f7e86 DW	110	ssize_t rc;
8c2f7e86 DW	111
87a30e1f	112	nd_device_lock(dev);
4be9c1fc	113	nvdimm_bus_lock(dev);
e1455744	114	rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
426824d6 DW	115	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
426824d6 DW	116	buf[len - 1] == '\n' ? "" : "\n");
8c2f7e86	117	nvdimm_bus_unlock(dev);
87a30e1f	118	nd_device_unlock(dev);
8c2f7e86 DW	119
	120	return rc;
	121	}
	122	static DEVICE_ATTR_RW(namespace);
	123
abe8b4e3 VV	124	static ssize_t size_show(struct device *dev,
	125	struct device_attribute attr, char buf)
	126	{
	127	struct nd_btt *nd_btt = to_nd_btt(dev);
	128	ssize_t rc;
	129
87a30e1f	130	nd_device_lock(dev);
abe8b4e3 VV	131	if (dev->driver)
	132	rc = sprintf(buf, "%llu\n", nd_btt->size);
	133	else {
	134	/* no size to convey if the btt instance is disabled */
	135	rc = -ENXIO;
	136	}
87a30e1f	137	nd_device_unlock(dev);
abe8b4e3 VV	138
	139	return rc;
	140	}
	141	static DEVICE_ATTR_RO(size);
	142
9dedc73a VV	143	static ssize_t log_zero_flags_show(struct device *dev,
	144	struct device_attribute attr, char buf)
	145	{
	146	return sprintf(buf, "Y\n");
	147	}
	148	static DEVICE_ATTR_RO(log_zero_flags);
	149
8c2f7e86 DW	150	static struct attribute *nd_btt_attributes[] = {
	151	&dev_attr_sector_size.attr,
	152	&dev_attr_namespace.attr,
	153	&dev_attr_uuid.attr,
abe8b4e3	154	&dev_attr_size.attr,
9dedc73a	155	&dev_attr_log_zero_flags.attr,
8c2f7e86 DW	156	NULL,
	157	};
	158
	159	static struct attribute_group nd_btt_attribute_group = {
	160	.attrs = nd_btt_attributes,
	161	};
	162
	163	static const struct attribute_group *nd_btt_attribute_groups[] = {
	164	&nd_btt_attribute_group,
	165	&nd_device_attribute_group,
74ae66c3	166	&nd_numa_attribute_group,
8c2f7e86 DW	167	NULL,
	168	};
	169
78c81cc8 DW	170	static const struct device_type nd_btt_device_type = {
	171	.name = "nd_btt",
	172	.release = nd_btt_release,
	173	.groups = nd_btt_attribute_groups,
	174	};
	175
	176	bool is_nd_btt(struct device *dev)
	177	{
	178	return dev->type == &nd_btt_device_type;
	179	}
	180	EXPORT_SYMBOL(is_nd_btt);
	181
8c2f7e86 DW	182	static struct device __nd_btt_create(struct nd_region nd_region,
	183	unsigned long lbasize, u8 *uuid,
	184	struct nd_namespace_common *ndns)
	185	{
	186	struct nd_btt *nd_btt;
	187	struct device *dev;
	188
	189	nd_btt = kzalloc(sizeof(*nd_btt), GFP_KERNEL);
	190	if (!nd_btt)
	191	return NULL;
	192
	193	nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL);
486fa92d AP	194	if (nd_btt->id < 0)
486fa92d AP	195	goto out_nd_btt;
8c2f7e86 DW	196
8c2f7e86 DW	197	nd_btt->lbasize = lbasize;
486fa92d	198	if (uuid) {
8c2f7e86	199	uuid = kmemdup(uuid, 16, GFP_KERNEL);
486fa92d AP	200	if (!uuid)
	201	goto out_put_id;
	202	}
8c2f7e86 DW	203	nd_btt->uuid = uuid;
	204	dev = &nd_btt->dev;
	205	dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
	206	dev->parent = &nd_region->dev;
	207	dev->type = &nd_btt_device_type;
8c2f7e86	208	device_initialize(&nd_btt->dev);
e1455744	209	if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
426824d6 DW	210	dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
426824d6 DW	211	dev_name(ndns->claim));
8c2f7e86 DW	212	put_device(dev);
	213	return NULL;
	214	}
	215	return dev;
486fa92d AP	216
	217	out_put_id:
	218	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
	219
	220	out_nd_btt:
	221	kfree(nd_btt);
	222	return NULL;
8c2f7e86 DW	223	}
	224
	225	struct device nd_btt_create(struct nd_region nd_region)
	226	{
	227	struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);
	228
d4c5725d	229	__nd_device_register(dev);
8c2f7e86 DW	230	return dev;
	231	}
	232
ab45e763 VV	233	/**
	234	* nd_btt_arena_is_valid - check if the metadata layout is valid
	235	* @nd_btt: device with BTT geometry and backing device info
	236	* @super: pointer to the arena's info block being tested
	237	*
	238	* Check consistency of the btt info block with itself by validating
6ec68954 VV	239	* the checksum, and with the parent namespace by verifying the
6ec68954 VV	240	* parent_uuid contained in the info block with the one supplied in.
ab45e763 VV	241	*
	242	* Returns:
	243	* false for an invalid info block, true for a valid one
	244	*/
	245	bool nd_btt_arena_is_valid(struct nd_btt nd_btt, struct btt_sb super)
	246	{
6ec68954	247	const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
ab45e763 VV	248	u64 checksum;
	249
	250	if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
	251	return false;
	252
ef40dda5	253	if (!guid_is_null((guid_t *)&super->parent_uuid))
6ec68954 VV	254	if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
	255	return false;
	256
ab45e763 VV	257	checksum = le64_to_cpu(super->checksum);
ab45e763 VV	258	super->checksum = 0;
e1455744	259	if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
ab45e763 VV	260	return false;
	261	super->checksum = cpu_to_le64(checksum);
	262
	263	/* TODO: figure out action for this */
	264	if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
	265	dev_info(&nd_btt->dev, "Found arena with an error flag\n");
	266
	267	return true;
	268	}
	269	EXPORT_SYMBOL(nd_btt_arena_is_valid);
	270
14e49454 VV	271	int nd_btt_version(struct nd_btt nd_btt, struct nd_namespace_common ndns,
	272	struct btt_sb *btt_sb)
	273	{
	274	if (ndns->claim_class == NVDIMM_CCLASS_BTT2) {
	275	/* Probe/setup for BTT v2.0 */
	276	nd_btt->initial_offset = 0;
	277	nd_btt->version_major = 2;
	278	nd_btt->version_minor = 0;
	279	if (nvdimm_read_bytes(ndns, 0, btt_sb, sizeof(*btt_sb), 0))
	280	return -ENXIO;
	281	if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
	282	return -ENODEV;
	283	if ((le16_to_cpu(btt_sb->version_major) != 2) \|\|
	284	(le16_to_cpu(btt_sb->version_minor) != 0))
	285	return -ENODEV;
	286	} else {
	287	/*
	288	* Probe/setup for BTT v1.1 (NVDIMM_CCLASS_NONE or
	289	* NVDIMM_CCLASS_BTT)
	290	*/
	291	nd_btt->initial_offset = SZ_4K;
	292	nd_btt->version_major = 1;
	293	nd_btt->version_minor = 1;
	294	if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb), 0))
	295	return -ENXIO;
	296	if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
	297	return -ENODEV;
	298	if ((le16_to_cpu(btt_sb->version_major) != 1) \|\|
	299	(le16_to_cpu(btt_sb->version_minor) != 1))
	300	return -ENODEV;
	301	}
	302	return 0;
	303	}
	304	EXPORT_SYMBOL(nd_btt_version);
	305
8c2f7e86 DW	306	static int __nd_btt_probe(struct nd_btt *nd_btt,
	307	struct nd_namespace_common ndns, struct btt_sb btt_sb)
	308	{
14e49454 VV	309	int rc;
14e49454 VV	310
8c2f7e86 DW	311	if (!btt_sb \|\| !ndns \|\| !nd_btt)
	312	return -ENODEV;
	313
8c2f7e86 DW	314	if (nvdimm_namespace_capacity(ndns) < SZ_16M)
	315	return -ENXIO;
	316
14e49454 VV	317	rc = nd_btt_version(nd_btt, ndns, btt_sb);
	318	if (rc < 0)
	319	return rc;
8c2f7e86 DW	320
	321	nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
	322	nd_btt->uuid = kmemdup(btt_sb->uuid, 16, GFP_KERNEL);
	323	if (!nd_btt->uuid)
	324	return -ENOMEM;
	325
	326	__nd_device_register(&nd_btt->dev);
	327
	328	return 0;
	329	}
	330
200c79da	331	int nd_btt_probe(struct device dev, struct nd_namespace_common ndns)
8c2f7e86 DW	332	{
8c2f7e86 DW	333	int rc;
e32bc729	334	struct device *btt_dev;
8c2f7e86 DW	335	struct btt_sb *btt_sb;
	336	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
	337
	338	if (ndns->force_raw)
	339	return -ENODEV;
	340
b3fde74e DW	341	switch (ndns->claim_class) {
	342	case NVDIMM_CCLASS_NONE:
	343	case NVDIMM_CCLASS_BTT:
14e49454	344	case NVDIMM_CCLASS_BTT2:
b3fde74e DW	345	break;
	346	default:
	347	return -ENODEV;
	348	}
	349
8c2f7e86	350	nvdimm_bus_lock(&ndns->dev);
e32bc729	351	btt_dev = __nd_btt_create(nd_region, 0, NULL, ndns);
8c2f7e86	352	nvdimm_bus_unlock(&ndns->dev);
e32bc729	353	if (!btt_dev)
8c2f7e86	354	return -ENOMEM;
e32bc729 DW	355	btt_sb = devm_kzalloc(dev, sizeof(*btt_sb), GFP_KERNEL);
e32bc729 DW	356	rc = __nd_btt_probe(to_nd_btt(btt_dev), ndns, btt_sb);
426824d6	357	dev_dbg(dev, "btt: %s\n", rc == 0 ? dev_name(btt_dev) : "<none>");
8c2f7e86	358	if (rc < 0) {
e32bc729	359	struct nd_btt *nd_btt = to_nd_btt(btt_dev);
e1455744	360
452bae0a	361	nd_detach_ndns(btt_dev, &nd_btt->ndns);
e32bc729	362	put_device(btt_dev);
8c2f7e86 DW	363	}
	364
	365	return rc;
	366	}
	367	EXPORT_SYMBOL(nd_btt_probe);