[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) {
			nd_pfn->mode = PFN_MODE_PMEM;
		} 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)
{
	u64 checksum, offset;
	struct nd_namespace_io *nsio;
	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
	struct nd_namespace_common *ndns = nd_pfn->ndns;
	const u8 *parent_uuid = nd_dev_to_uuid(&ndns->dev);

	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);

	if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
		return -ENODEV;

	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) {
d2c0f041	86	nd_pfn->mode = PFN_MODE_PMEM;
e1455744 DW	87	} else if (strncmp(buf, "ram\n", n) == 0
	88	\|\| strncmp(buf, "ram", n) == 0)
	89	nd_pfn->mode = PFN_MODE_RAM;
	90	else if (strncmp(buf, "none\n", n) == 0
	91	\|\| strncmp(buf, "none", n) == 0)
	92	nd_pfn->mode = PFN_MODE_NONE;
	93	else
	94	rc = -EINVAL;
	95	}
	96	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
	97	rc, buf, buf[len - 1] == '\n' ? "" : "\n");
	98	nvdimm_bus_unlock(dev);
	99	device_unlock(dev);
	100
	101	return rc ? rc : len;
	102	}
	103	static DEVICE_ATTR_RW(mode);
	104
315c5625 DW	105	static ssize_t align_show(struct device *dev,
	106	struct device_attribute attr, char buf)
	107	{
	108	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	109
	110	return sprintf(buf, "%lx\n", nd_pfn->align);
	111	}
	112
	113	static ssize_t __align_store(struct nd_pfn nd_pfn, const char buf)
	114	{
	115	unsigned long val;
	116	int rc;
	117
	118	rc = kstrtoul(buf, 0, &val);
	119	if (rc)
	120	return rc;
	121
	122	if (!is_power_of_2(val) \|\| val < PAGE_SIZE \|\| val > SZ_1G)
	123	return -EINVAL;
	124
	125	if (nd_pfn->dev.driver)
	126	return -EBUSY;
	127	else
	128	nd_pfn->align = val;
	129
	130	return 0;
	131	}
	132
	133	static ssize_t align_store(struct device *dev,
	134	struct device_attribute attr, const char buf, size_t len)
	135	{
	136	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	137	ssize_t rc;
	138
	139	device_lock(dev);
	140	nvdimm_bus_lock(dev);
	141	rc = __align_store(nd_pfn, buf);
	142	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
	143	rc, buf, buf[len - 1] == '\n' ? "" : "\n");
	144	nvdimm_bus_unlock(dev);
	145	device_unlock(dev);
	146
	147	return rc ? rc : len;
	148	}
	149	static DEVICE_ATTR_RW(align);
	150
e1455744 DW	151	static ssize_t uuid_show(struct device *dev,
	152	struct device_attribute attr, char buf)
	153	{
	154	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	155
	156	if (nd_pfn->uuid)
	157	return sprintf(buf, "%pUb\n", nd_pfn->uuid);
	158	return sprintf(buf, "\n");
	159	}
	160
	161	static ssize_t uuid_store(struct device *dev,
	162	struct device_attribute attr, const char buf, size_t len)
	163	{
	164	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	165	ssize_t rc;
	166
	167	device_lock(dev);
	168	rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
	169	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
	170	rc, buf, buf[len - 1] == '\n' ? "" : "\n");
	171	device_unlock(dev);
	172
	173	return rc ? rc : len;
	174	}
	175	static DEVICE_ATTR_RW(uuid);
	176
	177	static ssize_t namespace_show(struct device *dev,
	178	struct device_attribute attr, char buf)
	179	{
	180	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	181	ssize_t rc;
	182
	183	nvdimm_bus_lock(dev);
	184	rc = sprintf(buf, "%s\n", nd_pfn->ndns
	185	? dev_name(&nd_pfn->ndns->dev) : "");
	186	nvdimm_bus_unlock(dev);
	187	return rc;
	188	}
	189
	190	static ssize_t namespace_store(struct device *dev,
	191	struct device_attribute attr, const char buf, size_t len)
	192	{
	193	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
	194	ssize_t rc;
	195
e1455744	196	device_lock(dev);
4ca8b57a	197	nvdimm_bus_lock(dev);
e1455744 DW	198	rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
	199	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
	200	rc, buf, buf[len - 1] == '\n' ? "" : "\n");
e1455744	201	nvdimm_bus_unlock(dev);
4ca8b57a	202	device_unlock(dev);
e1455744 DW	203
	204	return rc;
	205	}
	206	static DEVICE_ATTR_RW(namespace);
	207
	208	static struct attribute *nd_pfn_attributes[] = {
	209	&dev_attr_mode.attr,
	210	&dev_attr_namespace.attr,
	211	&dev_attr_uuid.attr,
315c5625	212	&dev_attr_align.attr,
e1455744 DW	213	NULL,
	214	};
	215
	216	static struct attribute_group nd_pfn_attribute_group = {
	217	.attrs = nd_pfn_attributes,
	218	};
	219
	220	static const struct attribute_group *nd_pfn_attribute_groups[] = {
	221	&nd_pfn_attribute_group,
	222	&nd_device_attribute_group,
	223	&nd_numa_attribute_group,
	224	NULL,
	225	};
	226
	227	static struct device __nd_pfn_create(struct nd_region nd_region,
e1455744 DW	228	struct nd_namespace_common *ndns)
	229	{
	230	struct nd_pfn *nd_pfn;
	231	struct device *dev;
	232
	233	/* we can only create pages for contiguous ranged of pmem */
	234	if (!is_nd_pmem(&nd_region->dev))
	235	return NULL;
	236
	237	nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL);
	238	if (!nd_pfn)
	239	return NULL;
	240
	241	nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL);
	242	if (nd_pfn->id < 0) {
	243	kfree(nd_pfn);
	244	return NULL;
	245	}
	246
f7c6ab80	247	nd_pfn->mode = PFN_MODE_NONE;
315c5625	248	nd_pfn->align = HPAGE_SIZE;
e1455744 DW	249	dev = &nd_pfn->dev;
	250	dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
	251	dev->parent = &nd_region->dev;
	252	dev->type = &nd_pfn_device_type;
	253	dev->groups = nd_pfn_attribute_groups;
	254	device_initialize(&nd_pfn->dev);
	255	if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
	256	dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
	257	__func__, dev_name(ndns->claim));
	258	put_device(dev);
	259	return NULL;
	260	}
	261	return dev;
	262	}
	263
	264	struct device nd_pfn_create(struct nd_region nd_region)
	265	{
f7c6ab80	266	struct device *dev = __nd_pfn_create(nd_region, NULL);
e1455744 DW	267
	268	if (dev)
	269	__nd_device_register(dev);
	270	return dev;
	271	}
	272
32ab0a3f	273	int nd_pfn_validate(struct nd_pfn *nd_pfn)
e1455744	274	{
e1455744	275	u64 checksum, offset;
a34d5e8a DW	276	struct nd_namespace_io *nsio;
	277	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
	278	struct nd_namespace_common *ndns = nd_pfn->ndns;
	279	const u8 *parent_uuid = nd_dev_to_uuid(&ndns->dev);
e1455744 DW	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
a34d5e8a DW	299	if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
	300	return -ENODEV;
	301
e1455744 DW	302	switch (le32_to_cpu(pfn_sb->mode)) {
	303	case PFN_MODE_RAM:
	304	break;
	305	case PFN_MODE_PMEM:
	306	/* TODO: allocate from PMEM support */
	307	return -ENOTTY;
	308	default:
	309	return -ENXIO;
	310	}
	311
	312	if (!nd_pfn->uuid) {
	313	/* from probe we allocate */
	314	nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
	315	if (!nd_pfn->uuid)
	316	return -ENOMEM;
	317	} else {
	318	/* from init we validate */
	319	if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
	320	return -EINVAL;
	321	}
	322
315c5625 DW	323	if (nd_pfn->align > nvdimm_namespace_capacity(ndns)) {
	324	dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
	325	nd_pfn->align, nvdimm_namespace_capacity(ndns));
	326	return -EINVAL;
	327	}
	328
e1455744 DW	329	/*
	330	* These warnings are verbose because they can only trigger in
	331	* the case where the physical address alignment of the
	332	* namespace has changed since the pfn superblock was
	333	* established.
	334	*/
	335	offset = le64_to_cpu(pfn_sb->dataoff);
	336	nsio = to_nd_namespace_io(&ndns->dev);
9f1e8cee	337	if (offset >= resource_size(&nsio->res)) {
e1455744 DW	338	dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
	339	dev_name(&ndns->dev));
	340	return -EBUSY;
	341	}
	342
315c5625 DW	343	nd_pfn->align = 1UL << ilog2(offset);
	344	if (!is_power_of_2(offset) \|\| offset < PAGE_SIZE) {
	345	dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
	346	offset);
	347	return -ENXIO;
	348	}
	349
e1455744 DW	350	return 0;
e1455744 DW	351	}
32ab0a3f	352	EXPORT_SYMBOL(nd_pfn_validate);
e1455744 DW	353
	354	int nd_pfn_probe(struct nd_namespace_common ndns, void drvdata)
	355	{
	356	int rc;
	357	struct device *dev;
	358	struct nd_pfn *nd_pfn;
	359	struct nd_pfn_sb *pfn_sb;
	360	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
	361
	362	if (ndns->force_raw)
	363	return -ENODEV;
	364
	365	nvdimm_bus_lock(&ndns->dev);
f7c6ab80	366	dev = __nd_pfn_create(nd_region, ndns);
e1455744 DW	367	nvdimm_bus_unlock(&ndns->dev);
	368	if (!dev)
	369	return -ENOMEM;
	370	dev_set_drvdata(dev, drvdata);
	371	pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
	372	nd_pfn = to_nd_pfn(dev);
	373	nd_pfn->pfn_sb = pfn_sb;
	374	rc = nd_pfn_validate(nd_pfn);
	375	nd_pfn->pfn_sb = NULL;
	376	kfree(pfn_sb);
	377	dev_dbg(&ndns->dev, "%s: pfn: %s\n", __func__,
	378	rc == 0 ? dev_name(dev) : "<none>");
	379	if (rc < 0) {
	380	__nd_detach_ndns(dev, &nd_pfn->ndns);
	381	put_device(dev);
	382	} else
	383	__nd_device_register(&nd_pfn->dev);
	384
	385	return rc;
	386	}
	387	EXPORT_SYMBOL(nd_pfn_probe);