[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;
	struct nvdimm_bus *nvdimm_bus;

	if (!ndns)
		return;

	nvdimm_bus = walk_to_nvdimm_bus(&ndns->dev);
	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
	dev_WARN_ONCE(dev, 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);
	nvdimm_bus_lock(&ndns->dev);
	__nd_detach_ndns(dev, _ndns);
	nvdimm_bus_unlock(&ndns->dev);
	put_device(&ndns->dev);
}

bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
		struct nd_namespace_common **_ndns)
{
	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&attach->dev);

	if (attach->claim)
		return false;
	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
	dev_WARN_ONCE(dev, *_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;

	nvdimm_bus_lock(&attach->dev);
	claimed = __nd_attach_ndns(dev, attach, _ndns);
	nvdimm_bus_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,
		unsigned long flags)
{
	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
	unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
	sector_t sector = offset >> 9;
	int rc = 0;

	if (unlikely(!size))
		return 0;

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

	if (rw == READ) {
		if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
			return -EIO;
		return memcpy_mcsafe(buf, nsio->addr + offset, size);
	}

	if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
		/*
		 * FIXME: nsio_rw_bytes() may be called from atomic
		 * context in the btt case and the ACPI DSM path for
		 * clearing the error takes sleeping locks and allocates
		 * memory. An explicit error clearing path, and support
		 * for tracking badblocks in BTT metadata is needed to
		 * work around this collision.
		 */
		if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
				&& !(flags & NVDIMM_IO_ATOMIC)
				&& !ndns->claim) {
			long cleared;

			cleared = nvdimm_clear_poison(&ndns->dev,
					nsio->res.start + offset, size);
			if (cleared < size)
				rc = -EIO;
			if (cleared > 0 && cleared / 512) {
				cleared /= 512;
				badblocks_clear(&nsio->bb, sector, cleared);
			}
			invalidate_pmem(nsio->addr + offset, size);
		} else
			rc = -EIO;
	}

	memcpy_to_pmem(nsio->addr + offset, buf, size);
	nvdimm_flush(to_nd_region(ndns->dev.parent));

	return rc;
}

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(&ndns->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;
452bae0a	24	struct nvdimm_bus *nvdimm_bus;
e1455744	25
452bae0a DW	26	if (!ndns)
	27	return;
	28
	29	nvdimm_bus = walk_to_nvdimm_bus(&ndns->dev);
	30	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
9cf8bd52	31	dev_WARN_ONCE(dev, ndns->claim != dev, "%s: invalid claim\n", __func__);
e1455744 DW	32	ndns->claim = NULL;
	33	*_ndns = NULL;
	34	put_device(&ndns->dev);
	35	}
	36
	37	void nd_detach_ndns(struct device *dev,
	38	struct nd_namespace_common **_ndns)
	39	{
	40	struct nd_namespace_common ndns = _ndns;
	41
	42	if (!ndns)
	43	return;
	44	get_device(&ndns->dev);
452bae0a	45	nvdimm_bus_lock(&ndns->dev);
e1455744	46	__nd_detach_ndns(dev, _ndns);
452bae0a	47	nvdimm_bus_unlock(&ndns->dev);
e1455744 DW	48	put_device(&ndns->dev);
	49	}
	50
	51	bool __nd_attach_ndns(struct device dev, struct nd_namespace_common attach,
	52	struct nd_namespace_common **_ndns)
	53	{
452bae0a DW	54	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&attach->dev);
452bae0a DW	55
e1455744 DW	56	if (attach->claim)
e1455744 DW	57	return false;
452bae0a	58	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
9cf8bd52	59	dev_WARN_ONCE(dev, *_ndns, "%s: invalid claim\n", __func__);
e1455744 DW	60	attach->claim = dev;
	61	*_ndns = attach;
	62	get_device(&attach->dev);
	63	return true;
	64	}
	65
	66	bool nd_attach_ndns(struct device dev, struct nd_namespace_common attach,
	67	struct nd_namespace_common **_ndns)
	68	{
	69	bool claimed;
	70
452bae0a	71	nvdimm_bus_lock(&attach->dev);
e1455744	72	claimed = __nd_attach_ndns(dev, attach, _ndns);
452bae0a	73	nvdimm_bus_unlock(&attach->dev);
e1455744 DW	74	return claimed;
	75	}
	76
	77	static int namespace_match(struct device dev, void data)
	78	{
	79	char *name = data;
	80
	81	return strcmp(name, dev_name(dev)) == 0;
	82	}
	83
	84	static bool is_idle(struct device dev, struct nd_namespace_common ndns)
	85	{
	86	struct nd_region *nd_region = to_nd_region(dev->parent);
	87	struct device *seed = NULL;
	88
	89	if (is_nd_btt(dev))
	90	seed = nd_region->btt_seed;
	91	else if (is_nd_pfn(dev))
	92	seed = nd_region->pfn_seed;
cd03412a DW	93	else if (is_nd_dax(dev))
cd03412a DW	94	seed = nd_region->dax_seed;
e1455744 DW	95
	96	if (seed == dev \|\| ndns \|\| dev->driver)
	97	return false;
	98	return true;
	99	}
	100
03dca343 DW	101	struct nd_pfn to_nd_pfn_safe(struct device dev)
	102	{
	103	/*
	104	* pfn device attributes are re-used by dax device instances, so we
	105	* need to be careful to correct device-to-nd_pfn conversion.
	106	*/
	107	if (is_nd_pfn(dev))
	108	return to_nd_pfn(dev);
	109
	110	if (is_nd_dax(dev)) {
	111	struct nd_dax *nd_dax = to_nd_dax(dev);
	112
	113	return &nd_dax->nd_pfn;
	114	}
	115
	116	WARN_ON(1);
	117	return NULL;
	118	}
	119
e1455744 DW	120	static void nd_detach_and_reset(struct device *dev,
	121	struct nd_namespace_common **_ndns)
	122	{
	123	/* detach the namespace and destroy / reset the device */
452bae0a	124	__nd_detach_ndns(dev, _ndns);
e1455744 DW	125	if (is_idle(dev, *_ndns)) {
	126	nd_device_unregister(dev, ND_ASYNC);
	127	} else if (is_nd_btt(dev)) {
	128	struct nd_btt *nd_btt = to_nd_btt(dev);
	129
	130	nd_btt->lbasize = 0;
	131	kfree(nd_btt->uuid);
	132	nd_btt->uuid = NULL;
03dca343 DW	133	} else if (is_nd_pfn(dev) \|\| is_nd_dax(dev)) {
03dca343 DW	134	struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
e1455744 DW	135
	136	kfree(nd_pfn->uuid);
	137	nd_pfn->uuid = NULL;
	138	nd_pfn->mode = PFN_MODE_NONE;
	139	}
	140	}
	141
	142	ssize_t nd_namespace_store(struct device *dev,
	143	struct nd_namespace_common *_ndns, const char buf,
	144	size_t len)
	145	{
	146	struct nd_namespace_common *ndns;
	147	struct device *found;
	148	char *name;
	149
	150	if (dev->driver) {
	151	dev_dbg(dev, "%s: -EBUSY\n", __func__);
	152	return -EBUSY;
	153	}
	154
	155	name = kstrndup(buf, len, GFP_KERNEL);
	156	if (!name)
	157	return -ENOMEM;
	158	strim(name);
	159
	160	if (strncmp(name, "namespace", 9) == 0 \|\| strcmp(name, "") == 0)
	161	/* pass */;
	162	else {
	163	len = -EINVAL;
	164	goto out;
	165	}
	166
	167	ndns = *_ndns;
	168	if (strcmp(name, "") == 0) {
	169	nd_detach_and_reset(dev, _ndns);
	170	goto out;
	171	} else if (ndns) {
	172	dev_dbg(dev, "namespace already set to: %s\n",
	173	dev_name(&ndns->dev));
	174	len = -EBUSY;
	175	goto out;
	176	}
	177
	178	found = device_find_child(dev->parent, name, namespace_match);
	179	if (!found) {
	180	dev_dbg(dev, "'%s' not found under %s\n", name,
	181	dev_name(dev->parent));
	182	len = -ENODEV;
	183	goto out;
	184	}
	185
	186	ndns = to_ndns(found);
	187	if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
	188	dev_dbg(dev, "%s too small to host\n", name);
	189	len = -ENXIO;
	190	goto out_attach;
	191	}
	192
	193	WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
452bae0a	194	if (!__nd_attach_ndns(dev, ndns, _ndns)) {
e1455744 DW	195	dev_dbg(dev, "%s already claimed\n",
	196	dev_name(&ndns->dev));
	197	len = -EBUSY;
	198	}
	199
	200	out_attach:
	201	put_device(&ndns->dev); /* from device_find_child */
	202	out:
	203	kfree(name);
	204	return len;
	205	}
	206
	207	/*
	208	* nd_sb_checksum: compute checksum for a generic info block
	209	*
	210	* Returns a fletcher64 checksum of everything in the given info block
	211	* except the last field (since that's where the checksum lives).
	212	*/
	213	u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
	214	{
	215	u64 sum;
	216	__le64 sum_save;
	217
	218	BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
	219	BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
	220	BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);
	221
	222	sum_save = nd_gen_sb->checksum;
	223	nd_gen_sb->checksum = 0;
	224	sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
	225	nd_gen_sb->checksum = sum_save;
	226	return sum;
	227	}
	228	EXPORT_SYMBOL(nd_sb_checksum);
200c79da DW	229
200c79da DW	230	static int nsio_rw_bytes(struct nd_namespace_common *ndns,
3ae3d67b VV	231	resource_size_t offset, void *buf, size_t size, int rw,
3ae3d67b VV	232	unsigned long flags)
200c79da DW	233	{
200c79da DW	234	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
82bf1037 DJ	235	unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
	236	sector_t sector = offset >> 9;
	237	int rc = 0;
	238
	239	if (unlikely(!size))
	240	return 0;
200c79da DW	241
	242	if (unlikely(offset + size > nsio->size)) {
	243	dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
	244	return -EFAULT;
	245	}
	246
	247	if (rw == READ) {
82bf1037	248	if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
200c79da	249	return -EIO;
6abccd1b	250	return memcpy_mcsafe(buf, nsio->addr + offset, size);
d37806dc FF	251	}
	252
	253	if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
a3e9af95 DW	254	/*
	255	* FIXME: nsio_rw_bytes() may be called from atomic
	256	* context in the btt case and the ACPI DSM path for
	257	* clearing the error takes sleeping locks and allocates
	258	* memory. An explicit error clearing path, and support
	259	* for tracking badblocks in BTT metadata is needed to
	260	* work around this collision.
	261	*/
	262	if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
3ae3d67b VV	263	&& !(flags & NVDIMM_IO_ATOMIC)
3ae3d67b VV	264	&& !ndns->claim) {
d37806dc FF	265	long cleared;
d37806dc FF	266
97681f9b TK	267	cleared = nvdimm_clear_poison(&ndns->dev,
97681f9b TK	268	nsio->res.start + offset, size);
868f036f	269	if (cleared < size)
82bf1037	270	rc = -EIO;
868f036f DW	271	if (cleared > 0 && cleared / 512) {
	272	cleared /= 512;
	273	badblocks_clear(&nsio->bb, sector, cleared);
d37806dc	274	}
868f036f	275	invalidate_pmem(nsio->addr + offset, size);
d37806dc FF	276	} else
d37806dc FF	277	rc = -EIO;
200c79da DW	278	}
200c79da DW	279
d37806dc FF	280	memcpy_to_pmem(nsio->addr + offset, buf, size);
	281	nvdimm_flush(to_nd_region(ndns->dev.parent));
	282
82bf1037	283	return rc;
200c79da DW	284	}
	285
	286	int devm_nsio_enable(struct device dev, struct nd_namespace_io nsio)
	287	{
	288	struct resource *res = &nsio->res;
	289	struct nd_namespace_common *ndns = &nsio->common;
	290
	291	nsio->size = resource_size(res);
	292	if (!devm_request_mem_region(dev, res->start, resource_size(res),
450c6633	293	dev_name(&ndns->dev))) {
200c79da DW	294	dev_warn(dev, "could not reserve region %pR\n", res);
	295	return -EBUSY;
	296	}
	297
	298	ndns->rw_bytes = nsio_rw_bytes;
	299	if (devm_init_badblocks(dev, &nsio->bb))
	300	return -ENOMEM;
	301	nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
	302	&nsio->res);
	303
	304	nsio->addr = devm_memremap(dev, res->start, resource_size(res),
	305	ARCH_MEMREMAP_PMEM);
42588958 DW	306
42588958 DW	307	return PTR_ERR_OR_ZERO(nsio->addr);
200c79da DW	308	}
	309	EXPORT_SYMBOL_GPL(devm_nsio_enable);
	310
	311	void devm_nsio_disable(struct device dev, struct nd_namespace_io nsio)
	312	{
	313	struct resource *res = &nsio->res;
	314
	315	devm_memunmap(dev, nsio->addr);
	316	devm_exit_badblocks(dev, &nsio->bb);
	317	devm_release_mem_region(dev, res->start, resource_size(res));
	318	}
	319	EXPORT_SYMBOL_GPL(devm_nsio_disable);