[mirror_ubuntu-bionic-kernel.git] / drivers / nvdimm / pfn_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 "pfn.h"
#include "nd.h"

static void nd_pfn_release(struct device *dev)
{
	struct nd_region *nd_region = to_nd_region(dev->parent);
	struct nd_pfn *nd_pfn = to_nd_pfn(dev);

	dev_dbg(dev, "%s\n", __func__);
	nd_detach_ndns(&nd_pfn->dev, &nd_pfn->ndns);
	ida_simple_remove(&nd_region->pfn_ida, nd_pfn->id);
	kfree(nd_pfn->uuid);
	kfree(nd_pfn);
}

static struct device_type nd_pfn_device_type = {
	.name = "nd_pfn",
	.release = nd_pfn_release,
};

bool is_nd_pfn(struct device *dev)
{
	return dev ? dev->type == &nd_pfn_device_type : false;
}
EXPORT_SYMBOL(is_nd_pfn);

struct nd_pfn *to_nd_pfn(struct device *dev)
{
	struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev);

	WARN_ON(!is_nd_pfn(dev));
	return nd_pfn;
}
EXPORT_SYMBOL(to_nd_pfn);

static ssize_t mode_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct nd_pfn *nd_pfn = to_nd_pfn(dev);

	switch (nd_pfn->mode) {
	case PFN_MODE_RAM:
		return sprintf(buf, "ram\n");
	case PFN_MODE_PMEM:
		return sprintf(buf, "pmem\n");
	default:
		return sprintf(buf, "none\n");
	}
}

static ssize_t mode_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t len)
{
	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	ssize_t rc = 0;

	device_lock(dev);
	nvdimm_bus_lock(dev);
	if (dev->driver)
		rc = -EBUSY;
	else {
		size_t n = len - 1;

		if (strncmp(buf, "pmem\n", n) == 0
				|| strncmp(buf, "pmem", n) == 0) {
			/* TODO: allocate from PMEM support */
			rc = -ENOTTY;
		} else if (strncmp(buf, "ram\n", n) == 0
				|| strncmp(buf, "ram", n) == 0)
			nd_pfn->mode = PFN_MODE_RAM;
		else if (strncmp(buf, "none\n", n) == 0
				|| strncmp(buf, "none", n) == 0)
			nd_pfn->mode = PFN_MODE_NONE;
		else
			rc = -EINVAL;
	}
	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
	nvdimm_bus_unlock(dev);
	device_unlock(dev);

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

static ssize_t align_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct nd_pfn *nd_pfn = to_nd_pfn(dev);

	return sprintf(buf, "%lx\n", nd_pfn->align);
}

static ssize_t __align_store(struct nd_pfn *nd_pfn, const char *buf)
{
	unsigned long val;
	int rc;

	rc = kstrtoul(buf, 0, &val);
	if (rc)
		return rc;

	if (!is_power_of_2(val) || val < PAGE_SIZE || val > SZ_1G)
		return -EINVAL;

	if (nd_pfn->dev.driver)
		return -EBUSY;
	else
		nd_pfn->align = val;

	return 0;
}

static ssize_t align_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t len)
{
	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	ssize_t rc;

	device_lock(dev);
	nvdimm_bus_lock(dev);
	rc = __align_store(nd_pfn, buf);
	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
	nvdimm_bus_unlock(dev);
	device_unlock(dev);

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

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

	if (nd_pfn->uuid)
		return sprintf(buf, "%pUb\n", nd_pfn->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_pfn *nd_pfn = to_nd_pfn(dev);
	ssize_t rc;

	device_lock(dev);
	rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
			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_pfn *nd_pfn = to_nd_pfn(dev);
	ssize_t rc;

	nvdimm_bus_lock(dev);
	rc = sprintf(buf, "%s\n", nd_pfn->ndns
			? dev_name(&nd_pfn->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_pfn *nd_pfn = to_nd_pfn(dev);
	ssize_t rc;

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

	return rc;
}
static DEVICE_ATTR_RW(namespace);

static struct attribute *nd_pfn_attributes[] = {
	&dev_attr_mode.attr,
	&dev_attr_namespace.attr,
	&dev_attr_uuid.attr,
	&dev_attr_align.attr,
	NULL,
};

static struct attribute_group nd_pfn_attribute_group = {
	.attrs = nd_pfn_attributes,
};

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

static struct device *__nd_pfn_create(struct nd_region *nd_region,
		struct nd_namespace_common *ndns)
{
	struct nd_pfn *nd_pfn;
	struct device *dev;

	/* we can only create pages for contiguous ranged of pmem */
	if (!is_nd_pmem(&nd_region->dev))
		return NULL;

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

	nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL);
	if (nd_pfn->id < 0) {
		kfree(nd_pfn);
		return NULL;
	}

	nd_pfn->mode = PFN_MODE_NONE;
	nd_pfn->align = HPAGE_SIZE;
	dev = &nd_pfn->dev;
	dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
	dev->parent = &nd_region->dev;
	dev->type = &nd_pfn_device_type;
	dev->groups = nd_pfn_attribute_groups;
	device_initialize(&nd_pfn->dev);
	if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
		dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
				__func__, dev_name(ndns->claim));
		put_device(dev);
		return NULL;
	}
	return dev;
}

struct device *nd_pfn_create(struct nd_region *nd_region)
{
	struct device *dev = __nd_pfn_create(nd_region, NULL);

	if (dev)
		__nd_device_register(dev);
	return dev;
}

int nd_pfn_validate(struct nd_pfn *nd_pfn)
{
	struct nd_namespace_common *ndns = nd_pfn->ndns;
	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
	struct nd_namespace_io *nsio;
	u64 checksum, offset;

	if (!pfn_sb || !ndns)
		return -ENODEV;

	if (!is_nd_pmem(nd_pfn->dev.parent))
		return -ENODEV;

	if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb)))
		return -ENXIO;

	if (memcmp(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN) != 0)
		return -ENODEV;

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

	switch (le32_to_cpu(pfn_sb->mode)) {
	case PFN_MODE_RAM:
		break;
	case PFN_MODE_PMEM:
		/* TODO: allocate from PMEM support */
		return -ENOTTY;
	default:
		return -ENXIO;
	}

	if (!nd_pfn->uuid) {
		/* from probe we allocate */
		nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
		if (!nd_pfn->uuid)
			return -ENOMEM;
	} else {
		/* from init we validate */
		if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
			return -EINVAL;
	}

	if (nd_pfn->align > nvdimm_namespace_capacity(ndns)) {
		dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
				nd_pfn->align, nvdimm_namespace_capacity(ndns));
		return -EINVAL;
	}

	/*
	 * These warnings are verbose because they can only trigger in
	 * the case where the physical address alignment of the
	 * namespace has changed since the pfn superblock was
	 * established.
	 */
	offset = le64_to_cpu(pfn_sb->dataoff);
	nsio = to_nd_namespace_io(&ndns->dev);
	if (offset >= resource_size(&nsio->res)) {
		dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
				dev_name(&ndns->dev));
		return -EBUSY;
	}

	nd_pfn->align = 1UL << ilog2(offset);
	if (!is_power_of_2(offset) || offset < PAGE_SIZE) {
		dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
				offset);
		return -ENXIO;
	}

	return 0;
}
EXPORT_SYMBOL(nd_pfn_validate);

int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata)
{
	int rc;
	struct device *dev;
	struct nd_pfn *nd_pfn;
	struct nd_pfn_sb *pfn_sb;
	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);

	if (ndns->force_raw)
		return -ENODEV;

	nvdimm_bus_lock(&ndns->dev);
	dev = __nd_pfn_create(nd_region, ndns);
	nvdimm_bus_unlock(&ndns->dev);
	if (!dev)
		return -ENOMEM;
	dev_set_drvdata(dev, drvdata);
	pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
	nd_pfn = to_nd_pfn(dev);
	nd_pfn->pfn_sb = pfn_sb;
	rc = nd_pfn_validate(nd_pfn);
	nd_pfn->pfn_sb = NULL;
	kfree(pfn_sb);
	dev_dbg(&ndns->dev, "%s: pfn: %s\n", __func__,
			rc == 0 ? dev_name(dev) : "<none>");
	if (rc < 0) {
		__nd_detach_ndns(dev, &nd_pfn->ndns);
		put_device(dev);
	} else
		__nd_device_register(&nd_pfn->dev);

	return rc;
}
EXPORT_SYMBOL(nd_pfn_probe);
Commit	Line	Data
e1455744 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 "pfn.h"
	22	#include "nd.h"
	23
	24	static void nd_pfn_release(struct device *dev)
	25	{
	26	struct nd_region *nd_region = to_nd_region(dev->parent);
	27	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	28
	29	dev_dbg(dev, "%s\n", __func__);
	30	nd_detach_ndns(&nd_pfn->dev, &nd_pfn->ndns);
	31	ida_simple_remove(&nd_region->pfn_ida, nd_pfn->id);
	32	kfree(nd_pfn->uuid);
	33	kfree(nd_pfn);
	34	}
	35
	36	static struct device_type nd_pfn_device_type = {
	37	.name = "nd_pfn",
	38	.release = nd_pfn_release,
	39	};
	40
	41	bool is_nd_pfn(struct device *dev)
	42	{
	43	return dev ? dev->type == &nd_pfn_device_type : false;
	44	}
	45	EXPORT_SYMBOL(is_nd_pfn);
	46
	47	struct nd_pfn to_nd_pfn(struct device dev)
	48	{
	49	struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev);
	50
	51	WARN_ON(!is_nd_pfn(dev));
	52	return nd_pfn;
	53	}
	54	EXPORT_SYMBOL(to_nd_pfn);
	55
	56	static ssize_t mode_show(struct device *dev,
	57	struct device_attribute attr, char buf)
	58	{
	59	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	60
	61	switch (nd_pfn->mode) {
	62	case PFN_MODE_RAM:
	63	return sprintf(buf, "ram\n");
	64	case PFN_MODE_PMEM:
65	return sprintf(buf, "pmem\n");
66	default:
67	return sprintf(buf, "none\n");
68	}
69	}
70
71	static ssize_t mode_store(struct device *dev,
72	struct device_attribute attr, const char buf, size_t len)
73	{
74	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
75	ssize_t rc = 0;
76
77	device_lock(dev);
78	nvdimm_bus_lock(dev);
79	if (dev->driver)
80	rc = -EBUSY;
81	else {
82	size_t n = len - 1;
83
84	if (strncmp(buf, "pmem\n", n) == 0
85	\|\| strncmp(buf, "pmem", n) == 0) {
86	/* TODO: allocate from PMEM support */
87	rc = -ENOTTY;
88	} else if (strncmp(buf, "ram\n", n) == 0
89	\|\| strncmp(buf, "ram", n) == 0)
90	nd_pfn->mode = PFN_MODE_RAM;
91	else if (strncmp(buf, "none\n", n) == 0
92	\|\| strncmp(buf, "none", n) == 0)
93	nd_pfn->mode = PFN_MODE_NONE;
94	else
95	rc = -EINVAL;
96	}
97	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
98	rc, buf, buf[len - 1] == '\n' ? "" : "\n");
99	nvdimm_bus_unlock(dev);
100	device_unlock(dev);
101
102	return rc ? rc : len;
103	}
104	static DEVICE_ATTR_RW(mode);
105
315c5625 DW	106	static ssize_t align_show(struct device *dev,
	107	struct device_attribute attr, char buf)
	108	{
	109	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	110
	111	return sprintf(buf, "%lx\n", nd_pfn->align);
	112	}
	113
	114	static ssize_t __align_store(struct nd_pfn nd_pfn, const char buf)
	115	{
	116	unsigned long val;
	117	int rc;
	118
	119	rc = kstrtoul(buf, 0, &val);
	120	if (rc)
	121	return rc;
	122
	123	if (!is_power_of_2(val) \|\| val < PAGE_SIZE \|\| val > SZ_1G)
	124	return -EINVAL;
	125
	126	if (nd_pfn->dev.driver)
	127	return -EBUSY;
	128	else
	129	nd_pfn->align = val;
	130
	131	return 0;
	132	}
	133
	134	static ssize_t align_store(struct device *dev,
	135	struct device_attribute attr, const char buf, size_t len)
	136	{
	137	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	138	ssize_t rc;
	139
	140	device_lock(dev);
	141	nvdimm_bus_lock(dev);
	142	rc = __align_store(nd_pfn, buf);
	143	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
	144	rc, buf, buf[len - 1] == '\n' ? "" : "\n");
	145	nvdimm_bus_unlock(dev);
	146	device_unlock(dev);
	147
	148	return rc ? rc : len;
	149	}
	150	static DEVICE_ATTR_RW(align);
	151
e1455744 DW	152	static ssize_t uuid_show(struct device *dev,
	153	struct device_attribute attr, char buf)
	154	{
	155	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	156
	157	if (nd_pfn->uuid)
	158	return sprintf(buf, "%pUb\n", nd_pfn->uuid);
	159	return sprintf(buf, "\n");
	160	}
	161
	162	static ssize_t uuid_store(struct device *dev,
	163	struct device_attribute attr, const char buf, size_t len)
	164	{
	165	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	166	ssize_t rc;
	167
	168	device_lock(dev);
	169	rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
	170	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
	171	rc, buf, buf[len - 1] == '\n' ? "" : "\n");
	172	device_unlock(dev);
	173
	174	return rc ? rc : len;
	175	}
	176	static DEVICE_ATTR_RW(uuid);
	177
	178	static ssize_t namespace_show(struct device *dev,
	179	struct device_attribute attr, char buf)
	180	{
	181	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	182	ssize_t rc;
	183
	184	nvdimm_bus_lock(dev);
	185	rc = sprintf(buf, "%s\n", nd_pfn->ndns
	186	? dev_name(&nd_pfn->ndns->dev) : "");
	187	nvdimm_bus_unlock(dev);
	188	return rc;
	189	}
	190
	191	static ssize_t namespace_store(struct device *dev,
	192	struct device_attribute attr, const char buf, size_t len)
	193	{
	194	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	195	ssize_t rc;
	196
e1455744	197	device_lock(dev);
4ca8b57a	198	nvdimm_bus_lock(dev);
e1455744 DW	199	rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
	200	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
	201	rc, buf, buf[len - 1] == '\n' ? "" : "\n");
e1455744	202	nvdimm_bus_unlock(dev);
4ca8b57a	203	device_unlock(dev);
e1455744 DW	204
	205	return rc;
	206	}
	207	static DEVICE_ATTR_RW(namespace);
	208
	209	static struct attribute *nd_pfn_attributes[] = {
	210	&dev_attr_mode.attr,
	211	&dev_attr_namespace.attr,
	212	&dev_attr_uuid.attr,
315c5625	213	&dev_attr_align.attr,
e1455744 DW	214	NULL,
	215	};
	216
	217	static struct attribute_group nd_pfn_attribute_group = {
	218	.attrs = nd_pfn_attributes,
	219	};
	220
	221	static const struct attribute_group *nd_pfn_attribute_groups[] = {
	222	&nd_pfn_attribute_group,
	223	&nd_device_attribute_group,
	224	&nd_numa_attribute_group,
	225	NULL,
	226	};
	227
	228	static struct device __nd_pfn_create(struct nd_region nd_region,
e1455744 DW	229	struct nd_namespace_common *ndns)
	230	{
	231	struct nd_pfn *nd_pfn;
	232	struct device *dev;
	233
	234	/* we can only create pages for contiguous ranged of pmem */
	235	if (!is_nd_pmem(&nd_region->dev))
	236	return NULL;
	237
	238	nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL);
	239	if (!nd_pfn)
	240	return NULL;
	241
	242	nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL);
	243	if (nd_pfn->id < 0) {
	244	kfree(nd_pfn);
	245	return NULL;
	246	}
	247
f7c6ab80	248	nd_pfn->mode = PFN_MODE_NONE;
315c5625	249	nd_pfn->align = HPAGE_SIZE;
e1455744 DW	250	dev = &nd_pfn->dev;
	251	dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
	252	dev->parent = &nd_region->dev;
	253	dev->type = &nd_pfn_device_type;
	254	dev->groups = nd_pfn_attribute_groups;
	255	device_initialize(&nd_pfn->dev);
	256	if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
	257	dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
	258	__func__, dev_name(ndns->claim));
	259	put_device(dev);
	260	return NULL;
	261	}
	262	return dev;
	263	}
	264
	265	struct device nd_pfn_create(struct nd_region nd_region)
	266	{
f7c6ab80	267	struct device *dev = __nd_pfn_create(nd_region, NULL);
e1455744 DW	268
	269	if (dev)
	270	__nd_device_register(dev);
	271	return dev;
	272	}
	273
32ab0a3f	274	int nd_pfn_validate(struct nd_pfn *nd_pfn)
e1455744 DW	275	{
	276	struct nd_namespace_common *ndns = nd_pfn->ndns;
	277	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
	278	struct nd_namespace_io *nsio;
	279	u64 checksum, offset;
	280
	281	if (!pfn_sb \|\| !ndns)
	282	return -ENODEV;
	283
	284	if (!is_nd_pmem(nd_pfn->dev.parent))
	285	return -ENODEV;
	286
e1455744 DW	287	if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb)))
	288	return -ENXIO;
	289
	290	if (memcmp(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN) != 0)
	291	return -ENODEV;
	292
	293	checksum = le64_to_cpu(pfn_sb->checksum);
	294	pfn_sb->checksum = 0;
	295	if (checksum != nd_sb_checksum((struct nd_gen_sb *) pfn_sb))
	296	return -ENODEV;
	297	pfn_sb->checksum = cpu_to_le64(checksum);
	298
	299	switch (le32_to_cpu(pfn_sb->mode)) {
	300	case PFN_MODE_RAM:
	301	break;
	302	case PFN_MODE_PMEM:
	303	/* TODO: allocate from PMEM support */
	304	return -ENOTTY;
	305	default:
	306	return -ENXIO;
	307	}
	308
	309	if (!nd_pfn->uuid) {
	310	/* from probe we allocate */
	311	nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
	312	if (!nd_pfn->uuid)
	313	return -ENOMEM;
	314	} else {
	315	/* from init we validate */
	316	if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
	317	return -EINVAL;
	318	}
	319
315c5625 DW	320	if (nd_pfn->align > nvdimm_namespace_capacity(ndns)) {
	321	dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
	322	nd_pfn->align, nvdimm_namespace_capacity(ndns));
	323	return -EINVAL;
	324	}
	325
e1455744 DW	326	/*
	327	* These warnings are verbose because they can only trigger in
	328	* the case where the physical address alignment of the
	329	* namespace has changed since the pfn superblock was
	330	* established.
	331	*/
	332	offset = le64_to_cpu(pfn_sb->dataoff);
	333	nsio = to_nd_namespace_io(&ndns->dev);
9f1e8cee	334	if (offset >= resource_size(&nsio->res)) {
e1455744 DW	335	dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
	336	dev_name(&ndns->dev));
	337	return -EBUSY;
	338	}
	339
315c5625 DW	340	nd_pfn->align = 1UL << ilog2(offset);
	341	if (!is_power_of_2(offset) \|\| offset < PAGE_SIZE) {
	342	dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
	343	offset);
	344	return -ENXIO;
	345	}
	346
e1455744 DW	347	return 0;
e1455744 DW	348	}
32ab0a3f	349	EXPORT_SYMBOL(nd_pfn_validate);
e1455744 DW	350
	351	int nd_pfn_probe(struct nd_namespace_common ndns, void drvdata)
	352	{
	353	int rc;
	354	struct device *dev;
	355	struct nd_pfn *nd_pfn;
	356	struct nd_pfn_sb *pfn_sb;
	357	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
	358
	359	if (ndns->force_raw)
	360	return -ENODEV;
	361
	362	nvdimm_bus_lock(&ndns->dev);
f7c6ab80	363	dev = __nd_pfn_create(nd_region, ndns);
e1455744 DW	364	nvdimm_bus_unlock(&ndns->dev);
	365	if (!dev)
	366	return -ENOMEM;
	367	dev_set_drvdata(dev, drvdata);
	368	pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
	369	nd_pfn = to_nd_pfn(dev);
	370	nd_pfn->pfn_sb = pfn_sb;
	371	rc = nd_pfn_validate(nd_pfn);
	372	nd_pfn->pfn_sb = NULL;
	373	kfree(pfn_sb);
	374	dev_dbg(&ndns->dev, "%s: pfn: %s\n", __func__,
	375	rc == 0 ? dev_name(dev) : "<none>");
	376	if (rc < 0) {
	377	__nd_detach_ndns(dev, &nd_pfn->ndns);
	378	put_device(dev);
	379	} else
	380	__nd_device_register(&nd_pfn->dev);
	381
	382	return rc;
	383	}
	384	EXPORT_SYMBOL(nd_pfn_probe);