[linux-2.6-block.git] / arch / powerpc / platforms / pseries / papr_scm.c

// SPDX-License-Identifier: GPL-2.0

#define pr_fmt(fmt)	"papr-scm: " fmt

#include <linux/of.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/ndctl.h>
#include <linux/sched.h>
#include <linux/libnvdimm.h>
#include <linux/platform_device.h>

#include <asm/plpar_wrappers.h>

#define BIND_ANY_ADDR (~0ul)

#define PAPR_SCM_DIMM_CMD_MASK \
	((1ul << ND_CMD_GET_CONFIG_SIZE) | \
	 (1ul << ND_CMD_GET_CONFIG_DATA) | \
	 (1ul << ND_CMD_SET_CONFIG_DATA))

struct papr_scm_priv {
	struct platform_device *pdev;
	struct device_node *dn;
	uint32_t drc_index;
	uint64_t blocks;
	uint64_t block_size;
	int metadata_size;

	uint64_t bound_addr;

	struct nvdimm_bus_descriptor bus_desc;
	struct nvdimm_bus *bus;
	struct nvdimm *nvdimm;
	struct resource res;
	struct nd_region *region;
	struct nd_interleave_set nd_set;
};

static int drc_pmem_bind(struct papr_scm_priv *p)
{
	unsigned long ret[PLPAR_HCALL_BUFSIZE];
	uint64_t rc, token;
	uint64_t saved = 0;

	/*
	 * When the hypervisor cannot map all the requested memory in a single
	 * hcall it returns H_BUSY and we call again with the token until
	 * we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
	 * leave the system in an undefined state, so we wait.
	 */
	token = 0;

	do {
		rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
				p->blocks, BIND_ANY_ADDR, token);
		token = ret[0];
		if (!saved)
			saved = ret[1];
		cond_resched();
	} while (rc == H_BUSY);

	if (rc) {
		dev_err(&p->pdev->dev, "bind err: %lld\n", rc);
		return -ENXIO;
	}

	p->bound_addr = saved;

	dev_dbg(&p->pdev->dev, "bound drc %x to %pR\n", p->drc_index, &p->res);

	return 0;
}

static int drc_pmem_unbind(struct papr_scm_priv *p)
{
	unsigned long ret[PLPAR_HCALL_BUFSIZE];
	uint64_t rc, token;

	token = 0;

	/* NB: unbind has the same retry requirements mentioned above */
	do {
		rc = plpar_hcall(H_SCM_UNBIND_MEM, ret, p->drc_index,
				p->bound_addr, p->blocks, token);
		token = ret[0];
		cond_resched();
	} while (rc == H_BUSY);

	if (rc)
		dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);

	return !!rc;
}

static int papr_scm_meta_get(struct papr_scm_priv *p,
			struct nd_cmd_get_config_data_hdr *hdr)
{
	unsigned long data[PLPAR_HCALL_BUFSIZE];
	int64_t ret;

	if (hdr->in_offset >= p->metadata_size || hdr->in_length != 1)
		return -EINVAL;

	ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
			hdr->in_offset, 1);

	if (ret == H_PARAMETER) /* bad DRC index */
		return -ENODEV;
	if (ret)
		return -EINVAL; /* other invalid parameter */

	hdr->out_buf[0] = data[0] & 0xff;

	return 0;
}

static int papr_scm_meta_set(struct papr_scm_priv *p,
			struct nd_cmd_set_config_hdr *hdr)
{
	int64_t ret;

	if (hdr->in_offset >= p->metadata_size || hdr->in_length != 1)
		return -EINVAL;

	ret = plpar_hcall_norets(H_SCM_WRITE_METADATA,
			p->drc_index, hdr->in_offset, hdr->in_buf[0], 1);

	if (ret == H_PARAMETER) /* bad DRC index */
		return -ENODEV;
	if (ret)
		return -EINVAL; /* other invalid parameter */

	return 0;
}

int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
		unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc)
{
	struct nd_cmd_get_config_size *get_size_hdr;
	struct papr_scm_priv *p;

	/* Only dimm-specific calls are supported atm */
	if (!nvdimm)
		return -EINVAL;

	p = nvdimm_provider_data(nvdimm);

	switch (cmd) {
	case ND_CMD_GET_CONFIG_SIZE:
		get_size_hdr = buf;

		get_size_hdr->status = 0;
		get_size_hdr->max_xfer = 1;
		get_size_hdr->config_size = p->metadata_size;
		*cmd_rc = 0;
		break;

	case ND_CMD_GET_CONFIG_DATA:
		*cmd_rc = papr_scm_meta_get(p, buf);
		break;

	case ND_CMD_SET_CONFIG_DATA:
		*cmd_rc = papr_scm_meta_set(p, buf);
		break;

	default:
		return -EINVAL;
	}

	dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);

	return 0;
}

static const struct attribute_group *region_attr_groups[] = {
	&nd_region_attribute_group,
	&nd_device_attribute_group,
	&nd_mapping_attribute_group,
	&nd_numa_attribute_group,
	NULL,
};

static const struct attribute_group *bus_attr_groups[] = {
	&nvdimm_bus_attribute_group,
	NULL,
};

static const struct attribute_group *papr_scm_dimm_groups[] = {
	&nvdimm_attribute_group,
	&nd_device_attribute_group,
	NULL,
};

static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
{
	struct device *dev = &p->pdev->dev;
	struct nd_mapping_desc mapping;
	struct nd_region_desc ndr_desc;
	unsigned long dimm_flags;

	p->bus_desc.ndctl = papr_scm_ndctl;
	p->bus_desc.module = THIS_MODULE;
	p->bus_desc.of_node = p->pdev->dev.of_node;
	p->bus_desc.attr_groups = bus_attr_groups;
	p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL);

	if (!p->bus_desc.provider_name)
		return -ENOMEM;

	p->bus = nvdimm_bus_register(NULL, &p->bus_desc);
	if (!p->bus) {
		dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
		return -ENXIO;
	}

	dimm_flags = 0;
	set_bit(NDD_ALIASING, &dimm_flags);

	p->nvdimm = nvdimm_create(p->bus, p, papr_scm_dimm_groups,
				dimm_flags, PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
	if (!p->nvdimm) {
		dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
		goto err;
	}

	if (nvdimm_bus_check_dimm_count(p->bus, 1))
		goto err;

	/* now add the region */

	memset(&mapping, 0, sizeof(mapping));
	mapping.nvdimm = p->nvdimm;
	mapping.start = 0;
	mapping.size = p->blocks * p->block_size; // XXX: potential overflow?

	memset(&ndr_desc, 0, sizeof(ndr_desc));
	ndr_desc.attr_groups = region_attr_groups;
	ndr_desc.numa_node = dev_to_node(&p->pdev->dev);
	ndr_desc.target_node = ndr_desc.numa_node;
	ndr_desc.res = &p->res;
	ndr_desc.of_node = p->dn;
	ndr_desc.provider_data = p;
	ndr_desc.mapping = &mapping;
	ndr_desc.num_mappings = 1;
	ndr_desc.nd_set = &p->nd_set;
	set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);

	p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
	if (!p->region) {
		dev_err(dev, "Error registering region %pR from %pOF\n",
				ndr_desc.res, p->dn);
		goto err;
	}

	return 0;

err:	nvdimm_bus_unregister(p->bus);
	kfree(p->bus_desc.provider_name);
	return -ENXIO;
}

static int papr_scm_probe(struct platform_device *pdev)
{
	struct device_node *dn = pdev->dev.of_node;
	u32 drc_index, metadata_size;
	u64 blocks, block_size;
	struct papr_scm_priv *p;
	const char *uuid_str;
	u64 uuid[2];
	int rc;

	/* check we have all the required DT properties */
	if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) {
		dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
		return -ENODEV;
	}

	if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
		dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
		return -ENODEV;
	}

	if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
		dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
		return -ENODEV;
	}

	if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
		dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
		return -ENODEV;
	}

	p = kzalloc(sizeof(*p), GFP_KERNEL);
	if (!p)
		return -ENOMEM;

	/* optional DT properties */
	of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);

	p->dn = dn;
	p->drc_index = drc_index;
	p->block_size = block_size;
	p->blocks = blocks;

	/* We just need to ensure that set cookies are unique across */
	uuid_parse(uuid_str, (uuid_t *) uuid);
	p->nd_set.cookie1 = uuid[0];
	p->nd_set.cookie2 = uuid[1];

	/* might be zero */
	p->metadata_size = metadata_size;
	p->pdev = pdev;

	/* request the hypervisor to bind this region to somewhere in memory */
	rc = drc_pmem_bind(p);
	if (rc)
		goto err;

	/* setup the resource for the newly bound range */
	p->res.start = p->bound_addr;
	p->res.end   = p->bound_addr + p->blocks * p->block_size - 1;
	p->res.name  = pdev->name;
	p->res.flags = IORESOURCE_MEM;

	rc = papr_scm_nvdimm_init(p);
	if (rc)
		goto err2;

	platform_set_drvdata(pdev, p);

	return 0;

err2:	drc_pmem_unbind(p);
err:	kfree(p);
	return rc;
}

static int papr_scm_remove(struct platform_device *pdev)
{
	struct papr_scm_priv *p = platform_get_drvdata(pdev);

	nvdimm_bus_unregister(p->bus);
	drc_pmem_unbind(p);
	kfree(p);

	return 0;
}

static const struct of_device_id papr_scm_match[] = {
	{ .compatible = "ibm,pmemory" },
	{ },
};

static struct platform_driver papr_scm_driver = {
	.probe = papr_scm_probe,
	.remove = papr_scm_remove,
	.driver = {
		.name = "papr_scm",
		.owner = THIS_MODULE,
		.of_match_table = papr_scm_match,
	},
};

module_platform_driver(papr_scm_driver);
MODULE_DEVICE_TABLE(of, papr_scm_match);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("IBM Corporation");
Commit	Line	Data
b5beae5e OH	1	// SPDX-License-Identifier: GPL-2.0
	2
	3	#define pr_fmt(fmt) "papr-scm: " fmt
	4
	5	#include <linux/of.h>
	6	#include <linux/kernel.h>
	7	#include <linux/module.h>
	8	#include <linux/ioport.h>
	9	#include <linux/slab.h>
	10	#include <linux/ndctl.h>
	11	#include <linux/sched.h>
	12	#include <linux/libnvdimm.h>
	13	#include <linux/platform_device.h>
	14
	15	#include <asm/plpar_wrappers.h>
	16
	17	#define BIND_ANY_ADDR (~0ul)
	18
	19	#define PAPR_SCM_DIMM_CMD_MASK \
	20	((1ul << ND_CMD_GET_CONFIG_SIZE) \| \
	21	(1ul << ND_CMD_GET_CONFIG_DATA) \| \
	22	(1ul << ND_CMD_SET_CONFIG_DATA))
	23
	24	struct papr_scm_priv {
	25	struct platform_device *pdev;
	26	struct device_node *dn;
	27	uint32_t drc_index;
	28	uint64_t blocks;
	29	uint64_t block_size;
	30	int metadata_size;
	31
	32	uint64_t bound_addr;
	33
	34	struct nvdimm_bus_descriptor bus_desc;
	35	struct nvdimm_bus *bus;
	36	struct nvdimm *nvdimm;
	37	struct resource res;
	38	struct nd_region *region;
	39	struct nd_interleave_set nd_set;
	40	};
	41
	42	static int drc_pmem_bind(struct papr_scm_priv *p)
	43	{
	44	unsigned long ret[PLPAR_HCALL_BUFSIZE];
	45	uint64_t rc, token;
5a3840a4	46	uint64_t saved = 0;
b5beae5e OH	47
	48	/*
	49	* When the hypervisor cannot map all the requested memory in a single
	50	* hcall it returns H_BUSY and we call again with the token until
	51	* we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
	52	* leave the system in an undefined state, so we wait.
	53	*/
	54	token = 0;
	55
	56	do {
	57	rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
	58	p->blocks, BIND_ANY_ADDR, token);
409dd7dc	59	token = ret[0];
5a3840a4 OH	60	if (!saved)
5a3840a4 OH	61	saved = ret[1];
b5beae5e OH	62	cond_resched();
	63	} while (rc == H_BUSY);
	64
	65	if (rc) {
	66	dev_err(&p->pdev->dev, "bind err: %lld\n", rc);
	67	return -ENXIO;
	68	}
	69
5a3840a4	70	p->bound_addr = saved;
b5beae5e OH	71
	72	dev_dbg(&p->pdev->dev, "bound drc %x to %pR\n", p->drc_index, &p->res);
	73
	74	return 0;
	75	}
	76
	77	static int drc_pmem_unbind(struct papr_scm_priv *p)
	78	{
	79	unsigned long ret[PLPAR_HCALL_BUFSIZE];
	80	uint64_t rc, token;
	81
	82	token = 0;
	83
	84	/* NB: unbind has the same retry requirements mentioned above */
	85	do {
	86	rc = plpar_hcall(H_SCM_UNBIND_MEM, ret, p->drc_index,
	87	p->bound_addr, p->blocks, token);
409dd7dc	88	token = ret[0];
b5beae5e OH	89	cond_resched();
	90	} while (rc == H_BUSY);
	91
	92	if (rc)
	93	dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);
	94
	95	return !!rc;
	96	}
	97
	98	static int papr_scm_meta_get(struct papr_scm_priv *p,
	99	struct nd_cmd_get_config_data_hdr *hdr)
	100	{
	101	unsigned long data[PLPAR_HCALL_BUFSIZE];
	102	int64_t ret;
	103
	104	if (hdr->in_offset >= p->metadata_size \|\| hdr->in_length != 1)
	105	return -EINVAL;
	106
	107	ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
	108	hdr->in_offset, 1);
	109
	110	if (ret == H_PARAMETER) /* bad DRC index */
	111	return -ENODEV;
	112	if (ret)
	113	return -EINVAL; /* other invalid parameter */
	114
	115	hdr->out_buf[0] = data[0] & 0xff;
	116
	117	return 0;
	118	}
	119
	120	static int papr_scm_meta_set(struct papr_scm_priv *p,
	121	struct nd_cmd_set_config_hdr *hdr)
	122	{
	123	int64_t ret;
	124
	125	if (hdr->in_offset >= p->metadata_size \|\| hdr->in_length != 1)
	126	return -EINVAL;
	127
	128	ret = plpar_hcall_norets(H_SCM_WRITE_METADATA,
	129	p->drc_index, hdr->in_offset, hdr->in_buf[0], 1);
	130
	131	if (ret == H_PARAMETER) /* bad DRC index */
	132	return -ENODEV;
	133	if (ret)
	134	return -EINVAL; /* other invalid parameter */
	135
	136	return 0;
	137	}
	138
	139	int papr_scm_ndctl(struct nvdimm_bus_descriptor nd_desc, struct nvdimm nvdimm,
	140	unsigned int cmd, void buf, unsigned int buf_len, int cmd_rc)
	141	{
	142	struct nd_cmd_get_config_size *get_size_hdr;
	143	struct papr_scm_priv *p;
	144
	145	/* Only dimm-specific calls are supported atm */
	146	if (!nvdimm)
	147	return -EINVAL;
	148
	149	p = nvdimm_provider_data(nvdimm);
	150
	151	switch (cmd) {
	152	case ND_CMD_GET_CONFIG_SIZE:
153	get_size_hdr = buf;
154
155	get_size_hdr->status = 0;
156	get_size_hdr->max_xfer = 1;
157	get_size_hdr->config_size = p->metadata_size;
158	*cmd_rc = 0;
159	break;
160
161	case ND_CMD_GET_CONFIG_DATA:
162	*cmd_rc = papr_scm_meta_get(p, buf);
163	break;
164
165	case ND_CMD_SET_CONFIG_DATA:
166	*cmd_rc = papr_scm_meta_set(p, buf);
167	break;
168
169	default:
170	return -EINVAL;
171	}
172
173	dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);
174
175	return 0;
176	}
177
178	static const struct attribute_group *region_attr_groups[] = {
179	&nd_region_attribute_group,
180	&nd_device_attribute_group,
181	&nd_mapping_attribute_group,
182	&nd_numa_attribute_group,
183	NULL,
184	};
185
186	static const struct attribute_group *bus_attr_groups[] = {
187	&nvdimm_bus_attribute_group,
188	NULL,
189	};
190
191	static const struct attribute_group *papr_scm_dimm_groups[] = {
192	&nvdimm_attribute_group,
193	&nd_device_attribute_group,
194	NULL,
195	};
196
197	static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
198	{
199	struct device *dev = &p->pdev->dev;
200	struct nd_mapping_desc mapping;
201	struct nd_region_desc ndr_desc;
202	unsigned long dimm_flags;
203
204	p->bus_desc.ndctl = papr_scm_ndctl;
205	p->bus_desc.module = THIS_MODULE;
206	p->bus_desc.of_node = p->pdev->dev.of_node;
207	p->bus_desc.attr_groups = bus_attr_groups;
208	p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL);
209
210	if (!p->bus_desc.provider_name)
211	return -ENOMEM;
212
213	p->bus = nvdimm_bus_register(NULL, &p->bus_desc);
214	if (!p->bus) {
215	dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
216	return -ENXIO;
217	}
218
219	dimm_flags = 0;
220	set_bit(NDD_ALIASING, &dimm_flags);
221
222	p->nvdimm = nvdimm_create(p->bus, p, papr_scm_dimm_groups,
223	dimm_flags, PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
224	if (!p->nvdimm) {
225	dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
226	goto err;
227	}
228
b0d65a8c OH	229	if (nvdimm_bus_check_dimm_count(p->bus, 1))
	230	goto err;
	231
b5beae5e OH	232	/* now add the region */
	233
	234	memset(&mapping, 0, sizeof(mapping));
	235	mapping.nvdimm = p->nvdimm;
	236	mapping.start = 0;
	237	mapping.size = p->blocks * p->block_size; // XXX: potential overflow?
	238
	239	memset(&ndr_desc, 0, sizeof(ndr_desc));
	240	ndr_desc.attr_groups = region_attr_groups;
	241	ndr_desc.numa_node = dev_to_node(&p->pdev->dev);
8fc5c735	242	ndr_desc.target_node = ndr_desc.numa_node;
b5beae5e OH	243	ndr_desc.res = &p->res;
	244	ndr_desc.of_node = p->dn;
	245	ndr_desc.provider_data = p;
	246	ndr_desc.mapping = &mapping;
	247	ndr_desc.num_mappings = 1;
	248	ndr_desc.nd_set = &p->nd_set;
	249	set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
	250
	251	p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
	252	if (!p->region) {
	253	dev_err(dev, "Error registering region %pR from %pOF\n",
	254	ndr_desc.res, p->dn);
	255	goto err;
	256	}
	257
	258	return 0;
	259
	260	err: nvdimm_bus_unregister(p->bus);
	261	kfree(p->bus_desc.provider_name);
	262	return -ENXIO;
	263	}
	264
	265	static int papr_scm_probe(struct platform_device *pdev)
	266	{
b5beae5e	267	struct device_node *dn = pdev->dev.of_node;
683ec0e0 OH	268	u32 drc_index, metadata_size;
683ec0e0 OH	269	u64 blocks, block_size;
b5beae5e	270	struct papr_scm_priv *p;
43001c52 OH	271	const char *uuid_str;
43001c52 OH	272	u64 uuid[2];
b5beae5e OH	273	int rc;
	274
	275	/* check we have all the required DT properties */
	276	if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) {
	277	dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
	278	return -ENODEV;
	279	}
	280
683ec0e0 OH	281	if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
	282	dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
	283	return -ENODEV;
	284	}
	285
	286	if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
	287	dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
b5beae5e OH	288	return -ENODEV;
	289	}
	290
43001c52 OH	291	if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
	292	dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
	293	return -ENODEV;
	294	}
	295
b5beae5e OH	296	p = kzalloc(sizeof(*p), GFP_KERNEL);
	297	if (!p)
	298	return -ENOMEM;
	299
	300	/* optional DT properties */
	301	of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);
	302
	303	p->dn = dn;
	304	p->drc_index = drc_index;
683ec0e0 OH	305	p->block_size = block_size;
683ec0e0 OH	306	p->blocks = blocks;
b5beae5e	307
43001c52 OH	308	/* We just need to ensure that set cookies are unique across */
	309	uuid_parse(uuid_str, (uuid_t *) uuid);
	310	p->nd_set.cookie1 = uuid[0];
	311	p->nd_set.cookie2 = uuid[1];
	312
b5beae5e OH	313	/* might be zero */
	314	p->metadata_size = metadata_size;
	315	p->pdev = pdev;
	316
	317	/* request the hypervisor to bind this region to somewhere in memory */
	318	rc = drc_pmem_bind(p);
	319	if (rc)
	320	goto err;
	321
	322	/* setup the resource for the newly bound range */
	323	p->res.start = p->bound_addr;
59613526	324	p->res.end = p->bound_addr + p->blocks * p->block_size - 1;
b5beae5e OH	325	p->res.name = pdev->name;
	326	p->res.flags = IORESOURCE_MEM;
	327
	328	rc = papr_scm_nvdimm_init(p);
	329	if (rc)
	330	goto err2;
	331
	332	platform_set_drvdata(pdev, p);
	333
	334	return 0;
	335
	336	err2: drc_pmem_unbind(p);
	337	err: kfree(p);
	338	return rc;
	339	}
	340
	341	static int papr_scm_remove(struct platform_device *pdev)
	342	{
	343	struct papr_scm_priv *p = platform_get_drvdata(pdev);
	344
	345	nvdimm_bus_unregister(p->bus);
	346	drc_pmem_unbind(p);
	347	kfree(p);
	348
	349	return 0;
	350	}
	351
	352	static const struct of_device_id papr_scm_match[] = {
	353	{ .compatible = "ibm,pmemory" },
	354	{ },
	355	};
	356
	357	static struct platform_driver papr_scm_driver = {
	358	.probe = papr_scm_probe,
	359	.remove = papr_scm_remove,
	360	.driver = {
	361	.name = "papr_scm",
	362	.owner = THIS_MODULE,
	363	.of_match_table = papr_scm_match,
	364	},
	365	};
	366
	367	module_platform_driver(papr_scm_driver);
	368	MODULE_DEVICE_TABLE(of, papr_scm_match);
	369	MODULE_LICENSE("GPL");
	370	MODULE_AUTHOR("IBM Corporation");