[mirror_ubuntu-artful-kernel.git] / drivers / nvdimm / claim.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/device.h>
#include <linux/sizes.h>
#include <linux/pmem.h>
#include "nd-core.h"
#include "pfn.h"
#include "btt.h"
#include "nd.h"

void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns)
{
	struct nd_namespace_common *ndns = *_ndns;

	dev_WARN_ONCE(dev, !mutex_is_locked(&ndns->dev.mutex)
			|| ndns->claim != dev,
			"%s: invalid claim\n", __func__);
	ndns->claim = NULL;
	*_ndns = NULL;
	put_device(&ndns->dev);
}

void nd_detach_ndns(struct device *dev,
		struct nd_namespace_common **_ndns)
{
	struct nd_namespace_common *ndns = *_ndns;

	if (!ndns)
		return;
	get_device(&ndns->dev);
	device_lock(&ndns->dev);
	__nd_detach_ndns(dev, _ndns);
	device_unlock(&ndns->dev);
	put_device(&ndns->dev);
}

bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
		struct nd_namespace_common **_ndns)
{
	if (attach->claim)
		return false;
	dev_WARN_ONCE(dev, !mutex_is_locked(&attach->dev.mutex)
			|| *_ndns,
			"%s: invalid claim\n", __func__);
	attach->claim = dev;
	*_ndns = attach;
	get_device(&attach->dev);
	return true;
}

bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
		struct nd_namespace_common **_ndns)
{
	bool claimed;

	device_lock(&attach->dev);
	claimed = __nd_attach_ndns(dev, attach, _ndns);
	device_unlock(&attach->dev);
	return claimed;
}

static int namespace_match(struct device *dev, void *data)
{
	char *name = data;

	return strcmp(name, dev_name(dev)) == 0;
}

static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
{
	struct nd_region *nd_region = to_nd_region(dev->parent);
	struct device *seed = NULL;

	if (is_nd_btt(dev))
		seed = nd_region->btt_seed;
	else if (is_nd_pfn(dev))
		seed = nd_region->pfn_seed;
	else if (is_nd_dax(dev))
		seed = nd_region->dax_seed;

	if (seed == dev || ndns || dev->driver)
		return false;
	return true;
}

struct nd_pfn *to_nd_pfn_safe(struct device *dev)
{
	/*
	 * pfn device attributes are re-used by dax device instances, so we
	 * need to be careful to correct device-to-nd_pfn conversion.
	 */
	if (is_nd_pfn(dev))
		return to_nd_pfn(dev);

	if (is_nd_dax(dev)) {
		struct nd_dax *nd_dax = to_nd_dax(dev);

		return &nd_dax->nd_pfn;
	}

	WARN_ON(1);
	return NULL;
}

static void nd_detach_and_reset(struct device *dev,
		struct nd_namespace_common **_ndns)
{
	/* detach the namespace and destroy / reset the device */
	nd_detach_ndns(dev, _ndns);
	if (is_idle(dev, *_ndns)) {
		nd_device_unregister(dev, ND_ASYNC);
	} else if (is_nd_btt(dev)) {
		struct nd_btt *nd_btt = to_nd_btt(dev);

		nd_btt->lbasize = 0;
		kfree(nd_btt->uuid);
		nd_btt->uuid = NULL;
	} else if (is_nd_pfn(dev) || is_nd_dax(dev)) {
		struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);

		kfree(nd_pfn->uuid);
		nd_pfn->uuid = NULL;
		nd_pfn->mode = PFN_MODE_NONE;
	}
}

ssize_t nd_namespace_store(struct device *dev,
		struct nd_namespace_common **_ndns, const char *buf,
		size_t len)
{
	struct nd_namespace_common *ndns;
	struct device *found;
	char *name;

	if (dev->driver) {
		dev_dbg(dev, "%s: -EBUSY\n", __func__);
		return -EBUSY;
	}

	name = kstrndup(buf, len, GFP_KERNEL);
	if (!name)
		return -ENOMEM;
	strim(name);

	if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0)
		/* pass */;
	else {
		len = -EINVAL;
		goto out;
	}

	ndns = *_ndns;
	if (strcmp(name, "") == 0) {
		nd_detach_and_reset(dev, _ndns);
		goto out;
	} else if (ndns) {
		dev_dbg(dev, "namespace already set to: %s\n",
				dev_name(&ndns->dev));
		len = -EBUSY;
		goto out;
	}

	found = device_find_child(dev->parent, name, namespace_match);
	if (!found) {
		dev_dbg(dev, "'%s' not found under %s\n", name,
				dev_name(dev->parent));
		len = -ENODEV;
		goto out;
	}

	ndns = to_ndns(found);
	if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
		dev_dbg(dev, "%s too small to host\n", name);
		len = -ENXIO;
		goto out_attach;
	}

	WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
	if (!nd_attach_ndns(dev, ndns, _ndns)) {
		dev_dbg(dev, "%s already claimed\n",
				dev_name(&ndns->dev));
		len = -EBUSY;
	}

 out_attach:
	put_device(&ndns->dev); /* from device_find_child */
 out:
	kfree(name);
	return len;
}

/*
 * nd_sb_checksum: compute checksum for a generic info block
 *
 * Returns a fletcher64 checksum of everything in the given info block
 * except the last field (since that's where the checksum lives).
 */
u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
{
	u64 sum;
	__le64 sum_save;

	BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
	BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
	BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);

	sum_save = nd_gen_sb->checksum;
	nd_gen_sb->checksum = 0;
	sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
	nd_gen_sb->checksum = sum_save;
	return sum;
}
EXPORT_SYMBOL(nd_sb_checksum);

static int nsio_rw_bytes(struct nd_namespace_common *ndns,
		resource_size_t offset, void *buf, size_t size, int rw)
{
	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);

	if (unlikely(offset + size > nsio->size)) {
		dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
		return -EFAULT;
	}

	if (rw == READ) {
		unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);

		if (unlikely(is_bad_pmem(&nsio->bb, offset / 512, sz_align)))
			return -EIO;
		return memcpy_from_pmem(buf, nsio->addr + offset, size);
	} else {
		memcpy_to_pmem(nsio->addr + offset, buf, size);
		nvdimm_flush(to_nd_region(ndns->dev.parent));
	}

	return 0;
}

int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio)
{
	struct resource *res = &nsio->res;
	struct nd_namespace_common *ndns = &nsio->common;

	nsio->size = resource_size(res);
	if (!devm_request_mem_region(dev, res->start, resource_size(res),
				dev_name(dev))) {
		dev_warn(dev, "could not reserve region %pR\n", res);
		return -EBUSY;
	}

	ndns->rw_bytes = nsio_rw_bytes;
	if (devm_init_badblocks(dev, &nsio->bb))
		return -ENOMEM;
	nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
			&nsio->res);

	nsio->addr = devm_memremap(dev, res->start, resource_size(res),
			ARCH_MEMREMAP_PMEM);

	return PTR_ERR_OR_ZERO(nsio->addr);
}
EXPORT_SYMBOL_GPL(devm_nsio_enable);

void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio)
{
	struct resource *res = &nsio->res;

	devm_memunmap(dev, nsio->addr);
	devm_exit_badblocks(dev, &nsio->bb);
	devm_release_mem_region(dev, res->start, resource_size(res));
}
EXPORT_SYMBOL_GPL(devm_nsio_disable);
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/device.h>
	14	#include <linux/sizes.h>
200c79da	15	#include <linux/pmem.h>
e1455744 DW	16	#include "nd-core.h"
	17	#include "pfn.h"
	18	#include "btt.h"
	19	#include "nd.h"
	20
	21	void __nd_detach_ndns(struct device dev, struct nd_namespace_common *_ndns)
	22	{
	23	struct nd_namespace_common ndns = _ndns;
	24
	25	dev_WARN_ONCE(dev, !mutex_is_locked(&ndns->dev.mutex)
	26	\|\| ndns->claim != dev,
	27	"%s: invalid claim\n", __func__);
	28	ndns->claim = NULL;
	29	*_ndns = NULL;
	30	put_device(&ndns->dev);
	31	}
	32
	33	void nd_detach_ndns(struct device *dev,
	34	struct nd_namespace_common **_ndns)
	35	{
	36	struct nd_namespace_common ndns = _ndns;
	37
	38	if (!ndns)
	39	return;
	40	get_device(&ndns->dev);
	41	device_lock(&ndns->dev);
	42	__nd_detach_ndns(dev, _ndns);
	43	device_unlock(&ndns->dev);
	44	put_device(&ndns->dev);
	45	}
	46
	47	bool __nd_attach_ndns(struct device dev, struct nd_namespace_common attach,
	48	struct nd_namespace_common **_ndns)
	49	{
	50	if (attach->claim)
	51	return false;
	52	dev_WARN_ONCE(dev, !mutex_is_locked(&attach->dev.mutex)
	53	\|\| *_ndns,
	54	"%s: invalid claim\n", __func__);
	55	attach->claim = dev;
	56	*_ndns = attach;
	57	get_device(&attach->dev);
	58	return true;
	59	}
	60
	61	bool nd_attach_ndns(struct device dev, struct nd_namespace_common attach,
	62	struct nd_namespace_common **_ndns)
	63	{
	64	bool claimed;
	65
	66	device_lock(&attach->dev);
	67	claimed = __nd_attach_ndns(dev, attach, _ndns);
	68	device_unlock(&attach->dev);
	69	return claimed;
	70	}
	71
	72	static int namespace_match(struct device dev, void data)
	73	{
	74	char *name = data;
	75
	76	return strcmp(name, dev_name(dev)) == 0;
	77	}
	78
	79	static bool is_idle(struct device dev, struct nd_namespace_common ndns)
80	{
81	struct nd_region *nd_region = to_nd_region(dev->parent);
82	struct device *seed = NULL;
83
84	if (is_nd_btt(dev))
85	seed = nd_region->btt_seed;
86	else if (is_nd_pfn(dev))
87	seed = nd_region->pfn_seed;
cd03412a DW	88	else if (is_nd_dax(dev))
cd03412a DW	89	seed = nd_region->dax_seed;
e1455744 DW	90
	91	if (seed == dev \|\| ndns \|\| dev->driver)
	92	return false;
	93	return true;
	94	}
	95
03dca343 DW	96	struct nd_pfn to_nd_pfn_safe(struct device dev)
	97	{
	98	/*
	99	* pfn device attributes are re-used by dax device instances, so we
	100	* need to be careful to correct device-to-nd_pfn conversion.
	101	*/
	102	if (is_nd_pfn(dev))
	103	return to_nd_pfn(dev);
	104
	105	if (is_nd_dax(dev)) {
	106	struct nd_dax *nd_dax = to_nd_dax(dev);
	107
	108	return &nd_dax->nd_pfn;
	109	}
	110
	111	WARN_ON(1);
	112	return NULL;
	113	}
	114
e1455744 DW	115	static void nd_detach_and_reset(struct device *dev,
	116	struct nd_namespace_common **_ndns)
	117	{
	118	/* detach the namespace and destroy / reset the device */
	119	nd_detach_ndns(dev, _ndns);
	120	if (is_idle(dev, *_ndns)) {
	121	nd_device_unregister(dev, ND_ASYNC);
	122	} else if (is_nd_btt(dev)) {
	123	struct nd_btt *nd_btt = to_nd_btt(dev);
	124
	125	nd_btt->lbasize = 0;
	126	kfree(nd_btt->uuid);
	127	nd_btt->uuid = NULL;
03dca343 DW	128	} else if (is_nd_pfn(dev) \|\| is_nd_dax(dev)) {
03dca343 DW	129	struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
e1455744 DW	130
	131	kfree(nd_pfn->uuid);
	132	nd_pfn->uuid = NULL;
	133	nd_pfn->mode = PFN_MODE_NONE;
	134	}
	135	}
	136
	137	ssize_t nd_namespace_store(struct device *dev,
	138	struct nd_namespace_common *_ndns, const char buf,
	139	size_t len)
	140	{
	141	struct nd_namespace_common *ndns;
	142	struct device *found;
	143	char *name;
	144
	145	if (dev->driver) {
	146	dev_dbg(dev, "%s: -EBUSY\n", __func__);
	147	return -EBUSY;
	148	}
	149
	150	name = kstrndup(buf, len, GFP_KERNEL);
	151	if (!name)
	152	return -ENOMEM;
	153	strim(name);
	154
	155	if (strncmp(name, "namespace", 9) == 0 \|\| strcmp(name, "") == 0)
	156	/* pass */;
	157	else {
	158	len = -EINVAL;
	159	goto out;
	160	}
	161
	162	ndns = *_ndns;
	163	if (strcmp(name, "") == 0) {
	164	nd_detach_and_reset(dev, _ndns);
	165	goto out;
	166	} else if (ndns) {
	167	dev_dbg(dev, "namespace already set to: %s\n",
	168	dev_name(&ndns->dev));
	169	len = -EBUSY;
	170	goto out;
	171	}
	172
	173	found = device_find_child(dev->parent, name, namespace_match);
	174	if (!found) {
	175	dev_dbg(dev, "'%s' not found under %s\n", name,
	176	dev_name(dev->parent));
	177	len = -ENODEV;
	178	goto out;
	179	}
	180
	181	ndns = to_ndns(found);
	182	if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
	183	dev_dbg(dev, "%s too small to host\n", name);
	184	len = -ENXIO;
	185	goto out_attach;
	186	}
	187
	188	WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
	189	if (!nd_attach_ndns(dev, ndns, _ndns)) {
	190	dev_dbg(dev, "%s already claimed\n",
	191	dev_name(&ndns->dev));
	192	len = -EBUSY;
	193	}
194
195	out_attach:
196	put_device(&ndns->dev); /* from device_find_child */
197	out:
198	kfree(name);
199	return len;
200	}
201
202	/*
203	* nd_sb_checksum: compute checksum for a generic info block
204	*
205	* Returns a fletcher64 checksum of everything in the given info block
206	* except the last field (since that's where the checksum lives).
207	*/
208	u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
209	{
210	u64 sum;
211	__le64 sum_save;
212
213	BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
214	BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
215	BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);
216
217	sum_save = nd_gen_sb->checksum;
218	nd_gen_sb->checksum = 0;
219	sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
220	nd_gen_sb->checksum = sum_save;
221	return sum;
222	}
223	EXPORT_SYMBOL(nd_sb_checksum);
200c79da DW	224
	225	static int nsio_rw_bytes(struct nd_namespace_common *ndns,
	226	resource_size_t offset, void *buf, size_t size, int rw)
	227	{
	228	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
	229
	230	if (unlikely(offset + size > nsio->size)) {
	231	dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
	232	return -EFAULT;
	233	}
	234
	235	if (rw == READ) {
	236	unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
	237
	238	if (unlikely(is_bad_pmem(&nsio->bb, offset / 512, sz_align)))
	239	return -EIO;
	240	return memcpy_from_pmem(buf, nsio->addr + offset, size);
	241	} else {
	242	memcpy_to_pmem(nsio->addr + offset, buf, size);
91131dbd	243	nvdimm_flush(to_nd_region(ndns->dev.parent));
200c79da DW	244	}
	245
	246	return 0;
	247	}
	248
	249	int devm_nsio_enable(struct device dev, struct nd_namespace_io nsio)
	250	{
	251	struct resource *res = &nsio->res;
	252	struct nd_namespace_common *ndns = &nsio->common;
	253
	254	nsio->size = resource_size(res);
	255	if (!devm_request_mem_region(dev, res->start, resource_size(res),
	256	dev_name(dev))) {
	257	dev_warn(dev, "could not reserve region %pR\n", res);
	258	return -EBUSY;
	259	}
	260
	261	ndns->rw_bytes = nsio_rw_bytes;
	262	if (devm_init_badblocks(dev, &nsio->bb))
	263	return -ENOMEM;
	264	nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
	265	&nsio->res);
	266
	267	nsio->addr = devm_memremap(dev, res->start, resource_size(res),
	268	ARCH_MEMREMAP_PMEM);
42588958 DW	269
42588958 DW	270	return PTR_ERR_OR_ZERO(nsio->addr);
200c79da DW	271	}
	272	EXPORT_SYMBOL_GPL(devm_nsio_enable);
	273
	274	void devm_nsio_disable(struct device dev, struct nd_namespace_io nsio)
	275	{
	276	struct resource *res = &nsio->res;
	277
	278	devm_memunmap(dev, nsio->addr);
	279	devm_exit_badblocks(dev, &nsio->bb);
	280	devm_release_mem_region(dev, res->start, resource_size(res));
	281	}
	282	EXPORT_SYMBOL_GPL(devm_nsio_disable);