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

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

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

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

	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);
	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;

	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");
	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;

	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);
	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;

	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;
	}
	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 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;
	dev->groups = nd_btt_attribute_groups;
	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
8c2f7e86 DW	1	/*
	2	* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of version 2 of the GNU General Public License as
	6	* published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful, but
	9	* WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* General Public License for more details.
	12	*/
	13	#include <linux/blkdev.h>
	14	#include <linux/device.h>
	15	#include <linux/genhd.h>
	16	#include <linux/sizes.h>
	17	#include <linux/slab.h>
	18	#include <linux/fs.h>
	19	#include <linux/mm.h>
	20	#include "nd-core.h"
	21	#include "btt.h"
	22	#include "nd.h"
	23
8c2f7e86 DW	24	static void nd_btt_release(struct device *dev)
	25	{
	26	struct nd_region *nd_region = to_nd_region(dev->parent);
	27	struct nd_btt *nd_btt = to_nd_btt(dev);
	28
426824d6	29	dev_dbg(dev, "trace\n");
e1455744	30	nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
8c2f7e86 DW	31	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
	32	kfree(nd_btt->uuid);
	33	kfree(nd_btt);
	34	}
	35
	36	static struct device_type nd_btt_device_type = {
	37	.name = "nd_btt",
	38	.release = nd_btt_release,
	39	};
	40
	41	bool is_nd_btt(struct device *dev)
	42	{
	43	return dev->type == &nd_btt_device_type;
	44	}
	45	EXPORT_SYMBOL(is_nd_btt);
	46
	47	struct nd_btt to_nd_btt(struct device dev)
	48	{
	49	struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
	50
	51	WARN_ON(!is_nd_btt(dev));
	52	return nd_btt;
	53	}
	54	EXPORT_SYMBOL(to_nd_btt);
	55
41cd8b70 VV	56	static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
41cd8b70 VV	57	4096, 4104, 4160, 4224, 0 };
8c2f7e86 DW	58
	59	static ssize_t sector_size_show(struct device *dev,
	60	struct device_attribute attr, char buf)
	61	{
	62	struct nd_btt *nd_btt = to_nd_btt(dev);
	63
b2c48f9f	64	return nd_size_select_show(nd_btt->lbasize, btt_lbasize_supported, buf);
8c2f7e86 DW	65	}
	66
	67	static ssize_t sector_size_store(struct device *dev,
	68	struct device_attribute attr, const char buf, size_t len)
	69	{
	70	struct nd_btt *nd_btt = to_nd_btt(dev);
	71	ssize_t rc;
	72
	73	device_lock(dev);
	74	nvdimm_bus_lock(dev);
b2c48f9f	75	rc = nd_size_select_store(dev, buf, &nd_btt->lbasize,
8c2f7e86	76	btt_lbasize_supported);
426824d6 DW	77	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
426824d6 DW	78	buf[len - 1] == '\n' ? "" : "\n");
8c2f7e86 DW	79	nvdimm_bus_unlock(dev);
	80	device_unlock(dev);
	81
	82	return rc ? rc : len;
	83	}
	84	static DEVICE_ATTR_RW(sector_size);
	85
	86	static ssize_t uuid_show(struct device *dev,
	87	struct device_attribute attr, char buf)
	88	{
	89	struct nd_btt *nd_btt = to_nd_btt(dev);
	90
	91	if (nd_btt->uuid)
	92	return sprintf(buf, "%pUb\n", nd_btt->uuid);
	93	return sprintf(buf, "\n");
	94	}
	95
	96	static ssize_t uuid_store(struct device *dev,
	97	struct device_attribute attr, const char buf, size_t len)
	98	{
	99	struct nd_btt *nd_btt = to_nd_btt(dev);
	100	ssize_t rc;
	101
	102	device_lock(dev);
	103	rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
426824d6 DW	104	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
426824d6 DW	105	buf[len - 1] == '\n' ? "" : "\n");
8c2f7e86 DW	106	device_unlock(dev);
	107
	108	return rc ? rc : len;
	109	}
	110	static DEVICE_ATTR_RW(uuid);
	111
	112	static ssize_t namespace_show(struct device *dev,
	113	struct device_attribute attr, char buf)
	114	{
	115	struct nd_btt *nd_btt = to_nd_btt(dev);
	116	ssize_t rc;
	117
	118	nvdimm_bus_lock(dev);
	119	rc = sprintf(buf, "%s\n", nd_btt->ndns
	120	? dev_name(&nd_btt->ndns->dev) : "");
	121	nvdimm_bus_unlock(dev);
	122	return rc;
	123	}
	124
8c2f7e86 DW	125	static ssize_t namespace_store(struct device *dev,
	126	struct device_attribute attr, const char buf, size_t len)
	127	{
e1455744	128	struct nd_btt *nd_btt = to_nd_btt(dev);
8c2f7e86 DW	129	ssize_t rc;
8c2f7e86 DW	130
8c2f7e86	131	device_lock(dev);
4be9c1fc	132	nvdimm_bus_lock(dev);
e1455744	133	rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
426824d6 DW	134	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
426824d6 DW	135	buf[len - 1] == '\n' ? "" : "\n");
8c2f7e86	136	nvdimm_bus_unlock(dev);
4be9c1fc	137	device_unlock(dev);
8c2f7e86 DW	138
	139	return rc;
	140	}
	141	static DEVICE_ATTR_RW(namespace);
	142
abe8b4e3 VV	143	static ssize_t size_show(struct device *dev,
	144	struct device_attribute attr, char buf)
	145	{
	146	struct nd_btt *nd_btt = to_nd_btt(dev);
	147	ssize_t rc;
	148
	149	device_lock(dev);
	150	if (dev->driver)
	151	rc = sprintf(buf, "%llu\n", nd_btt->size);
	152	else {
	153	/* no size to convey if the btt instance is disabled */
	154	rc = -ENXIO;
	155	}
	156	device_unlock(dev);
	157
	158	return rc;
	159	}
	160	static DEVICE_ATTR_RO(size);
	161
9dedc73a VV	162	static ssize_t log_zero_flags_show(struct device *dev,
	163	struct device_attribute attr, char buf)
	164	{
	165	return sprintf(buf, "Y\n");
	166	}
	167	static DEVICE_ATTR_RO(log_zero_flags);
	168
8c2f7e86 DW	169	static struct attribute *nd_btt_attributes[] = {
	170	&dev_attr_sector_size.attr,
	171	&dev_attr_namespace.attr,
	172	&dev_attr_uuid.attr,
abe8b4e3	173	&dev_attr_size.attr,
9dedc73a	174	&dev_attr_log_zero_flags.attr,
8c2f7e86 DW	175	NULL,
	176	};
	177
	178	static struct attribute_group nd_btt_attribute_group = {
	179	.attrs = nd_btt_attributes,
	180	};
	181
	182	static const struct attribute_group *nd_btt_attribute_groups[] = {
	183	&nd_btt_attribute_group,
	184	&nd_device_attribute_group,
74ae66c3	185	&nd_numa_attribute_group,
8c2f7e86 DW	186	NULL,
	187	};
	188
	189	static struct device __nd_btt_create(struct nd_region nd_region,
	190	unsigned long lbasize, u8 *uuid,
	191	struct nd_namespace_common *ndns)
	192	{
	193	struct nd_btt *nd_btt;
	194	struct device *dev;
	195
	196	nd_btt = kzalloc(sizeof(*nd_btt), GFP_KERNEL);
	197	if (!nd_btt)
	198	return NULL;
	199
	200	nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL);
486fa92d AP	201	if (nd_btt->id < 0)
486fa92d AP	202	goto out_nd_btt;
8c2f7e86 DW	203
8c2f7e86 DW	204	nd_btt->lbasize = lbasize;
486fa92d	205	if (uuid) {
8c2f7e86	206	uuid = kmemdup(uuid, 16, GFP_KERNEL);
486fa92d AP	207	if (!uuid)
	208	goto out_put_id;
	209	}
8c2f7e86 DW	210	nd_btt->uuid = uuid;
	211	dev = &nd_btt->dev;
	212	dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
	213	dev->parent = &nd_region->dev;
	214	dev->type = &nd_btt_device_type;
	215	dev->groups = nd_btt_attribute_groups;
	216	device_initialize(&nd_btt->dev);
e1455744	217	if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
426824d6 DW	218	dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
426824d6 DW	219	dev_name(ndns->claim));
8c2f7e86 DW	220	put_device(dev);
	221	return NULL;
	222	}
	223	return dev;
486fa92d AP	224
	225	out_put_id:
	226	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
	227
	228	out_nd_btt:
	229	kfree(nd_btt);
	230	return NULL;
8c2f7e86 DW	231	}
	232
	233	struct device nd_btt_create(struct nd_region nd_region)
	234	{
	235	struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);
	236
d4c5725d	237	__nd_device_register(dev);
8c2f7e86 DW	238	return dev;
	239	}
	240
ab45e763 VV	241	/**
	242	* nd_btt_arena_is_valid - check if the metadata layout is valid
	243	* @nd_btt: device with BTT geometry and backing device info
	244	* @super: pointer to the arena's info block being tested
	245	*
	246	* Check consistency of the btt info block with itself by validating
6ec68954 VV	247	* the checksum, and with the parent namespace by verifying the
6ec68954 VV	248	* parent_uuid contained in the info block with the one supplied in.
ab45e763 VV	249	*
	250	* Returns:
	251	* false for an invalid info block, true for a valid one
	252	*/
	253	bool nd_btt_arena_is_valid(struct nd_btt nd_btt, struct btt_sb super)
	254	{
6ec68954	255	const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
ab45e763 VV	256	u64 checksum;
	257
	258	if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
	259	return false;
	260
ef40dda5	261	if (!guid_is_null((guid_t *)&super->parent_uuid))
6ec68954 VV	262	if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
	263	return false;
	264
ab45e763 VV	265	checksum = le64_to_cpu(super->checksum);
ab45e763 VV	266	super->checksum = 0;
e1455744	267	if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
ab45e763 VV	268	return false;
	269	super->checksum = cpu_to_le64(checksum);
	270
	271	/* TODO: figure out action for this */
	272	if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
	273	dev_info(&nd_btt->dev, "Found arena with an error flag\n");
	274
	275	return true;
	276	}
	277	EXPORT_SYMBOL(nd_btt_arena_is_valid);
	278
14e49454 VV	279	int nd_btt_version(struct nd_btt nd_btt, struct nd_namespace_common ndns,
	280	struct btt_sb *btt_sb)
	281	{
	282	if (ndns->claim_class == NVDIMM_CCLASS_BTT2) {
	283	/* Probe/setup for BTT v2.0 */
	284	nd_btt->initial_offset = 0;
	285	nd_btt->version_major = 2;
	286	nd_btt->version_minor = 0;
	287	if (nvdimm_read_bytes(ndns, 0, btt_sb, sizeof(*btt_sb), 0))
	288	return -ENXIO;
	289	if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
	290	return -ENODEV;
	291	if ((le16_to_cpu(btt_sb->version_major) != 2) \|\|
	292	(le16_to_cpu(btt_sb->version_minor) != 0))
	293	return -ENODEV;
	294	} else {
	295	/*
	296	* Probe/setup for BTT v1.1 (NVDIMM_CCLASS_NONE or
	297	* NVDIMM_CCLASS_BTT)
	298	*/
	299	nd_btt->initial_offset = SZ_4K;
	300	nd_btt->version_major = 1;
	301	nd_btt->version_minor = 1;
	302	if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb), 0))
	303	return -ENXIO;
	304	if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
	305	return -ENODEV;
	306	if ((le16_to_cpu(btt_sb->version_major) != 1) \|\|
	307	(le16_to_cpu(btt_sb->version_minor) != 1))
	308	return -ENODEV;
	309	}
	310	return 0;
	311	}
	312	EXPORT_SYMBOL(nd_btt_version);
	313
8c2f7e86 DW	314	static int __nd_btt_probe(struct nd_btt *nd_btt,
	315	struct nd_namespace_common ndns, struct btt_sb btt_sb)
	316	{
14e49454 VV	317	int rc;
14e49454 VV	318
8c2f7e86 DW	319	if (!btt_sb \|\| !ndns \|\| !nd_btt)
	320	return -ENODEV;
	321
8c2f7e86 DW	322	if (nvdimm_namespace_capacity(ndns) < SZ_16M)
	323	return -ENXIO;
	324
14e49454 VV	325	rc = nd_btt_version(nd_btt, ndns, btt_sb);
	326	if (rc < 0)
	327	return rc;
8c2f7e86 DW	328
	329	nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
	330	nd_btt->uuid = kmemdup(btt_sb->uuid, 16, GFP_KERNEL);
	331	if (!nd_btt->uuid)
	332	return -ENOMEM;
	333
	334	__nd_device_register(&nd_btt->dev);
	335
	336	return 0;
	337	}
	338
200c79da	339	int nd_btt_probe(struct device dev, struct nd_namespace_common ndns)
8c2f7e86 DW	340	{
8c2f7e86 DW	341	int rc;
e32bc729	342	struct device *btt_dev;
8c2f7e86 DW	343	struct btt_sb *btt_sb;
	344	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
	345
	346	if (ndns->force_raw)
	347	return -ENODEV;
	348
b3fde74e DW	349	switch (ndns->claim_class) {
	350	case NVDIMM_CCLASS_NONE:
	351	case NVDIMM_CCLASS_BTT:
14e49454	352	case NVDIMM_CCLASS_BTT2:
b3fde74e DW	353	break;
	354	default:
	355	return -ENODEV;
	356	}
	357
8c2f7e86	358	nvdimm_bus_lock(&ndns->dev);
e32bc729	359	btt_dev = __nd_btt_create(nd_region, 0, NULL, ndns);
8c2f7e86	360	nvdimm_bus_unlock(&ndns->dev);
e32bc729	361	if (!btt_dev)
8c2f7e86	362	return -ENOMEM;
e32bc729 DW	363	btt_sb = devm_kzalloc(dev, sizeof(*btt_sb), GFP_KERNEL);
e32bc729 DW	364	rc = __nd_btt_probe(to_nd_btt(btt_dev), ndns, btt_sb);
426824d6	365	dev_dbg(dev, "btt: %s\n", rc == 0 ? dev_name(btt_dev) : "<none>");
8c2f7e86	366	if (rc < 0) {
e32bc729	367	struct nd_btt *nd_btt = to_nd_btt(btt_dev);
e1455744	368
452bae0a	369	nd_detach_ndns(btt_dev, &nd_btt->ndns);
e32bc729	370	put_device(btt_dev);
8c2f7e86 DW	371	}
	372
	373	return rc;
	374	}
	375	EXPORT_SYMBOL(nd_btt_probe);