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 #include <linux/delay.h>
15 #include <linux/seq_buf.h>
16 #include <linux/nd.h>
17 
18 #include <asm/plpar_wrappers.h>
19 #include <asm/papr_pdsm.h>
20 #include <asm/mce.h>
21 
22 #define BIND_ANY_ADDR (~0ul)
23 
24 #define PAPR_SCM_DIMM_CMD_MASK \
25 	((1ul << ND_CMD_GET_CONFIG_SIZE) | \
26 	 (1ul << ND_CMD_GET_CONFIG_DATA) | \
27 	 (1ul << ND_CMD_SET_CONFIG_DATA) | \
28 	 (1ul << ND_CMD_CALL))
29 
30 /* DIMM health bitmap bitmap indicators */
31 /* SCM device is unable to persist memory contents */
32 #define PAPR_PMEM_UNARMED                   (1ULL << (63 - 0))
33 /* SCM device failed to persist memory contents */
34 #define PAPR_PMEM_SHUTDOWN_DIRTY            (1ULL << (63 - 1))
35 /* SCM device contents are persisted from previous IPL */
36 #define PAPR_PMEM_SHUTDOWN_CLEAN            (1ULL << (63 - 2))
37 /* SCM device contents are not persisted from previous IPL */
38 #define PAPR_PMEM_EMPTY                     (1ULL << (63 - 3))
39 /* SCM device memory life remaining is critically low */
40 #define PAPR_PMEM_HEALTH_CRITICAL           (1ULL << (63 - 4))
41 /* SCM device will be garded off next IPL due to failure */
42 #define PAPR_PMEM_HEALTH_FATAL              (1ULL << (63 - 5))
43 /* SCM contents cannot persist due to current platform health status */
44 #define PAPR_PMEM_HEALTH_UNHEALTHY          (1ULL << (63 - 6))
45 /* SCM device is unable to persist memory contents in certain conditions */
46 #define PAPR_PMEM_HEALTH_NON_CRITICAL       (1ULL << (63 - 7))
47 /* SCM device is encrypted */
48 #define PAPR_PMEM_ENCRYPTED                 (1ULL << (63 - 8))
49 /* SCM device has been scrubbed and locked */
50 #define PAPR_PMEM_SCRUBBED_AND_LOCKED       (1ULL << (63 - 9))
51 
52 /* Bits status indicators for health bitmap indicating unarmed dimm */
53 #define PAPR_PMEM_UNARMED_MASK (PAPR_PMEM_UNARMED |		\
54 				PAPR_PMEM_HEALTH_UNHEALTHY)
55 
56 /* Bits status indicators for health bitmap indicating unflushed dimm */
57 #define PAPR_PMEM_BAD_SHUTDOWN_MASK (PAPR_PMEM_SHUTDOWN_DIRTY)
58 
59 /* Bits status indicators for health bitmap indicating unrestored dimm */
60 #define PAPR_PMEM_BAD_RESTORE_MASK  (PAPR_PMEM_EMPTY)
61 
62 /* Bit status indicators for smart event notification */
63 #define PAPR_PMEM_SMART_EVENT_MASK (PAPR_PMEM_HEALTH_CRITICAL | \
64 				    PAPR_PMEM_HEALTH_FATAL |	\
65 				    PAPR_PMEM_HEALTH_UNHEALTHY)
66 
67 #define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
68 #define PAPR_SCM_PERF_STATS_VERSION 0x1
69 
70 /* Struct holding a single performance metric */
71 struct papr_scm_perf_stat {
72 	u8 stat_id[8];
73 	__be64 stat_val;
74 } __packed;
75 
76 /* Struct exchanged between kernel and PHYP for fetching drc perf stats */
77 struct papr_scm_perf_stats {
78 	u8 eye_catcher[8];
79 	/* Should be PAPR_SCM_PERF_STATS_VERSION */
80 	__be32 stats_version;
81 	/* Number of stats following */
82 	__be32 num_statistics;
83 	/* zero or more performance matrics */
84 	struct papr_scm_perf_stat scm_statistic[];
85 } __packed;
86 
87 /* private struct associated with each region */
88 struct papr_scm_priv {
89 	struct platform_device *pdev;
90 	struct device_node *dn;
91 	uint32_t drc_index;
92 	uint64_t blocks;
93 	uint64_t block_size;
94 	int metadata_size;
95 	bool is_volatile;
96 	bool hcall_flush_required;
97 
98 	uint64_t bound_addr;
99 
100 	struct nvdimm_bus_descriptor bus_desc;
101 	struct nvdimm_bus *bus;
102 	struct nvdimm *nvdimm;
103 	struct resource res;
104 	struct nd_region *region;
105 	struct nd_interleave_set nd_set;
106 	struct list_head region_list;
107 
108 	/* Protect dimm health data from concurrent read/writes */
109 	struct mutex health_mutex;
110 
111 	/* Last time the health information of the dimm was updated */
112 	unsigned long lasthealth_jiffies;
113 
114 	/* Health information for the dimm */
115 	u64 health_bitmap;
116 
117 	/* length of the stat buffer as expected by phyp */
118 	size_t stat_buffer_len;
119 };
120 
121 static int papr_scm_pmem_flush(struct nd_region *nd_region,
122 			       struct bio *bio __maybe_unused)
123 {
124 	struct papr_scm_priv *p = nd_region_provider_data(nd_region);
125 	unsigned long ret_buf[PLPAR_HCALL_BUFSIZE], token = 0;
126 	long rc;
127 
128 	dev_dbg(&p->pdev->dev, "flush drc 0x%x", p->drc_index);
129 
130 	do {
131 		rc = plpar_hcall(H_SCM_FLUSH, ret_buf, p->drc_index, token);
132 		token = ret_buf[0];
133 
134 		/* Check if we are stalled for some time */
135 		if (H_IS_LONG_BUSY(rc)) {
136 			msleep(get_longbusy_msecs(rc));
137 			rc = H_BUSY;
138 		} else if (rc == H_BUSY) {
139 			cond_resched();
140 		}
141 	} while (rc == H_BUSY);
142 
143 	if (rc) {
144 		dev_err(&p->pdev->dev, "flush error: %ld", rc);
145 		rc = -EIO;
146 	} else {
147 		dev_dbg(&p->pdev->dev, "flush drc 0x%x complete", p->drc_index);
148 	}
149 
150 	return rc;
151 }
152 
153 static LIST_HEAD(papr_nd_regions);
154 static DEFINE_MUTEX(papr_ndr_lock);
155 
156 static int drc_pmem_bind(struct papr_scm_priv *p)
157 {
158 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
159 	uint64_t saved = 0;
160 	uint64_t token;
161 	int64_t rc;
162 
163 	/*
164 	 * When the hypervisor cannot map all the requested memory in a single
165 	 * hcall it returns H_BUSY and we call again with the token until
166 	 * we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
167 	 * leave the system in an undefined state, so we wait.
168 	 */
169 	token = 0;
170 
171 	do {
172 		rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
173 				p->blocks, BIND_ANY_ADDR, token);
174 		token = ret[0];
175 		if (!saved)
176 			saved = ret[1];
177 		cond_resched();
178 	} while (rc == H_BUSY);
179 
180 	if (rc)
181 		return rc;
182 
183 	p->bound_addr = saved;
184 	dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n",
185 		p->drc_index, (unsigned long)saved);
186 	return rc;
187 }
188 
189 static void drc_pmem_unbind(struct papr_scm_priv *p)
190 {
191 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
192 	uint64_t token = 0;
193 	int64_t rc;
194 
195 	dev_dbg(&p->pdev->dev, "unbind drc 0x%x\n", p->drc_index);
196 
197 	/* NB: unbind has the same retry requirements as drc_pmem_bind() */
198 	do {
199 
200 		/* Unbind of all SCM resources associated with drcIndex */
201 		rc = plpar_hcall(H_SCM_UNBIND_ALL, ret, H_UNBIND_SCOPE_DRC,
202 				 p->drc_index, token);
203 		token = ret[0];
204 
205 		/* Check if we are stalled for some time */
206 		if (H_IS_LONG_BUSY(rc)) {
207 			msleep(get_longbusy_msecs(rc));
208 			rc = H_BUSY;
209 		} else if (rc == H_BUSY) {
210 			cond_resched();
211 		}
212 
213 	} while (rc == H_BUSY);
214 
215 	if (rc)
216 		dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);
217 	else
218 		dev_dbg(&p->pdev->dev, "unbind drc 0x%x complete\n",
219 			p->drc_index);
220 
221 	return;
222 }
223 
224 static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
225 {
226 	unsigned long start_addr;
227 	unsigned long end_addr;
228 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
229 	int64_t rc;
230 
231 
232 	rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
233 			 p->drc_index, 0);
234 	if (rc)
235 		goto err_out;
236 	start_addr = ret[0];
237 
238 	/* Make sure the full region is bound. */
239 	rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
240 			 p->drc_index, p->blocks - 1);
241 	if (rc)
242 		goto err_out;
243 	end_addr = ret[0];
244 
245 	if ((end_addr - start_addr) != ((p->blocks - 1) * p->block_size))
246 		goto err_out;
247 
248 	p->bound_addr = start_addr;
249 	dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n", p->drc_index, start_addr);
250 	return rc;
251 
252 err_out:
253 	dev_info(&p->pdev->dev,
254 		 "Failed to query, trying an unbind followed by bind");
255 	drc_pmem_unbind(p);
256 	return drc_pmem_bind(p);
257 }
258 
259 /*
260  * Query the Dimm performance stats from PHYP and copy them (if returned) to
261  * provided struct papr_scm_perf_stats instance 'stats' that can hold atleast
262  * (num_stats + header) bytes.
263  * - If buff_stats == NULL the return value is the size in byes of the buffer
264  * needed to hold all supported performance-statistics.
265  * - If buff_stats != NULL and num_stats == 0 then we copy all known
266  * performance-statistics to 'buff_stat' and expect to be large enough to
267  * hold them.
268  * - if buff_stats != NULL and num_stats > 0 then copy the requested
269  * performance-statistics to buff_stats.
270  */
271 static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p,
272 				    struct papr_scm_perf_stats *buff_stats,
273 				    unsigned int num_stats)
274 {
275 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
276 	size_t size;
277 	s64 rc;
278 
279 	/* Setup the out buffer */
280 	if (buff_stats) {
281 		memcpy(buff_stats->eye_catcher,
282 		       PAPR_SCM_PERF_STATS_EYECATCHER, 8);
283 		buff_stats->stats_version =
284 			cpu_to_be32(PAPR_SCM_PERF_STATS_VERSION);
285 		buff_stats->num_statistics =
286 			cpu_to_be32(num_stats);
287 
288 		/*
289 		 * Calculate the buffer size based on num-stats provided
290 		 * or use the prefetched max buffer length
291 		 */
292 		if (num_stats)
293 			/* Calculate size from the num_stats */
294 			size = sizeof(struct papr_scm_perf_stats) +
295 				num_stats * sizeof(struct papr_scm_perf_stat);
296 		else
297 			size = p->stat_buffer_len;
298 	} else {
299 		/* In case of no out buffer ignore the size */
300 		size = 0;
301 	}
302 
303 	/* Do the HCALL asking PHYP for info */
304 	rc = plpar_hcall(H_SCM_PERFORMANCE_STATS, ret, p->drc_index,
305 			 buff_stats ? virt_to_phys(buff_stats) : 0,
306 			 size);
307 
308 	/* Check if the error was due to an unknown stat-id */
309 	if (rc == H_PARTIAL) {
310 		dev_err(&p->pdev->dev,
311 			"Unknown performance stats, Err:0x%016lX\n", ret[0]);
312 		return -ENOENT;
313 	} else if (rc == H_AUTHORITY) {
314 		dev_info(&p->pdev->dev,
315 			 "Permission denied while accessing performance stats");
316 		return -EPERM;
317 	} else if (rc == H_UNSUPPORTED) {
318 		dev_dbg(&p->pdev->dev, "Performance stats unsupported\n");
319 		return -EOPNOTSUPP;
320 	} else if (rc != H_SUCCESS) {
321 		dev_err(&p->pdev->dev,
322 			"Failed to query performance stats, Err:%lld\n", rc);
323 		return -EIO;
324 
325 	} else if (!size) {
326 		/* Handle case where stat buffer size was requested */
327 		dev_dbg(&p->pdev->dev,
328 			"Performance stats size %ld\n", ret[0]);
329 		return ret[0];
330 	}
331 
332 	/* Successfully fetched the requested stats from phyp */
333 	dev_dbg(&p->pdev->dev,
334 		"Performance stats returned %d stats\n",
335 		be32_to_cpu(buff_stats->num_statistics));
336 	return 0;
337 }
338 
339 /*
340  * Issue hcall to retrieve dimm health info and populate papr_scm_priv with the
341  * health information.
342  */
343 static int __drc_pmem_query_health(struct papr_scm_priv *p)
344 {
345 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
346 	long rc;
347 
348 	/* issue the hcall */
349 	rc = plpar_hcall(H_SCM_HEALTH, ret, p->drc_index);
350 	if (rc != H_SUCCESS) {
351 		dev_err(&p->pdev->dev,
352 			"Failed to query health information, Err:%ld\n", rc);
353 		return -ENXIO;
354 	}
355 
356 	p->lasthealth_jiffies = jiffies;
357 	p->health_bitmap = ret[0] & ret[1];
358 
359 	dev_dbg(&p->pdev->dev,
360 		"Queried dimm health info. Bitmap:0x%016lx Mask:0x%016lx\n",
361 		ret[0], ret[1]);
362 
363 	return 0;
364 }
365 
366 /* Min interval in seconds for assuming stable dimm health */
367 #define MIN_HEALTH_QUERY_INTERVAL 60
368 
369 /* Query cached health info and if needed call drc_pmem_query_health */
370 static int drc_pmem_query_health(struct papr_scm_priv *p)
371 {
372 	unsigned long cache_timeout;
373 	int rc;
374 
375 	/* Protect concurrent modifications to papr_scm_priv */
376 	rc = mutex_lock_interruptible(&p->health_mutex);
377 	if (rc)
378 		return rc;
379 
380 	/* Jiffies offset for which the health data is assumed to be same */
381 	cache_timeout = p->lasthealth_jiffies +
382 		msecs_to_jiffies(MIN_HEALTH_QUERY_INTERVAL * 1000);
383 
384 	/* Fetch new health info is its older than MIN_HEALTH_QUERY_INTERVAL */
385 	if (time_after(jiffies, cache_timeout))
386 		rc = __drc_pmem_query_health(p);
387 	else
388 		/* Assume cached health data is valid */
389 		rc = 0;
390 
391 	mutex_unlock(&p->health_mutex);
392 	return rc;
393 }
394 
395 static int papr_scm_meta_get(struct papr_scm_priv *p,
396 			     struct nd_cmd_get_config_data_hdr *hdr)
397 {
398 	unsigned long data[PLPAR_HCALL_BUFSIZE];
399 	unsigned long offset, data_offset;
400 	int len, read;
401 	int64_t ret;
402 
403 	if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
404 		return -EINVAL;
405 
406 	for (len = hdr->in_length; len; len -= read) {
407 
408 		data_offset = hdr->in_length - len;
409 		offset = hdr->in_offset + data_offset;
410 
411 		if (len >= 8)
412 			read = 8;
413 		else if (len >= 4)
414 			read = 4;
415 		else if (len >= 2)
416 			read = 2;
417 		else
418 			read = 1;
419 
420 		ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
421 				  offset, read);
422 
423 		if (ret == H_PARAMETER) /* bad DRC index */
424 			return -ENODEV;
425 		if (ret)
426 			return -EINVAL; /* other invalid parameter */
427 
428 		switch (read) {
429 		case 8:
430 			*(uint64_t *)(hdr->out_buf + data_offset) = be64_to_cpu(data[0]);
431 			break;
432 		case 4:
433 			*(uint32_t *)(hdr->out_buf + data_offset) = be32_to_cpu(data[0] & 0xffffffff);
434 			break;
435 
436 		case 2:
437 			*(uint16_t *)(hdr->out_buf + data_offset) = be16_to_cpu(data[0] & 0xffff);
438 			break;
439 
440 		case 1:
441 			*(uint8_t *)(hdr->out_buf + data_offset) = (data[0] & 0xff);
442 			break;
443 		}
444 	}
445 	return 0;
446 }
447 
448 static int papr_scm_meta_set(struct papr_scm_priv *p,
449 			     struct nd_cmd_set_config_hdr *hdr)
450 {
451 	unsigned long offset, data_offset;
452 	int len, wrote;
453 	unsigned long data;
454 	__be64 data_be;
455 	int64_t ret;
456 
457 	if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
458 		return -EINVAL;
459 
460 	for (len = hdr->in_length; len; len -= wrote) {
461 
462 		data_offset = hdr->in_length - len;
463 		offset = hdr->in_offset + data_offset;
464 
465 		if (len >= 8) {
466 			data = *(uint64_t *)(hdr->in_buf + data_offset);
467 			data_be = cpu_to_be64(data);
468 			wrote = 8;
469 		} else if (len >= 4) {
470 			data = *(uint32_t *)(hdr->in_buf + data_offset);
471 			data &= 0xffffffff;
472 			data_be = cpu_to_be32(data);
473 			wrote = 4;
474 		} else if (len >= 2) {
475 			data = *(uint16_t *)(hdr->in_buf + data_offset);
476 			data &= 0xffff;
477 			data_be = cpu_to_be16(data);
478 			wrote = 2;
479 		} else {
480 			data_be = *(uint8_t *)(hdr->in_buf + data_offset);
481 			data_be &= 0xff;
482 			wrote = 1;
483 		}
484 
485 		ret = plpar_hcall_norets(H_SCM_WRITE_METADATA, p->drc_index,
486 					 offset, data_be, wrote);
487 		if (ret == H_PARAMETER) /* bad DRC index */
488 			return -ENODEV;
489 		if (ret)
490 			return -EINVAL; /* other invalid parameter */
491 	}
492 
493 	return 0;
494 }
495 
496 /*
497  * Do a sanity checks on the inputs args to dimm-control function and return
498  * '0' if valid. Validation of PDSM payloads happens later in
499  * papr_scm_service_pdsm.
500  */
501 static int is_cmd_valid(struct nvdimm *nvdimm, unsigned int cmd, void *buf,
502 			unsigned int buf_len)
503 {
504 	unsigned long cmd_mask = PAPR_SCM_DIMM_CMD_MASK;
505 	struct nd_cmd_pkg *nd_cmd;
506 	struct papr_scm_priv *p;
507 	enum papr_pdsm pdsm;
508 
509 	/* Only dimm-specific calls are supported atm */
510 	if (!nvdimm)
511 		return -EINVAL;
512 
513 	/* get the provider data from struct nvdimm */
514 	p = nvdimm_provider_data(nvdimm);
515 
516 	if (!test_bit(cmd, &cmd_mask)) {
517 		dev_dbg(&p->pdev->dev, "Unsupported cmd=%u\n", cmd);
518 		return -EINVAL;
519 	}
520 
521 	/* For CMD_CALL verify pdsm request */
522 	if (cmd == ND_CMD_CALL) {
523 		/* Verify the envelope and envelop size */
524 		if (!buf ||
525 		    buf_len < (sizeof(struct nd_cmd_pkg) + ND_PDSM_HDR_SIZE)) {
526 			dev_dbg(&p->pdev->dev, "Invalid pkg size=%u\n",
527 				buf_len);
528 			return -EINVAL;
529 		}
530 
531 		/* Verify that the nd_cmd_pkg.nd_family is correct */
532 		nd_cmd = (struct nd_cmd_pkg *)buf;
533 
534 		if (nd_cmd->nd_family != NVDIMM_FAMILY_PAPR) {
535 			dev_dbg(&p->pdev->dev, "Invalid pkg family=0x%llx\n",
536 				nd_cmd->nd_family);
537 			return -EINVAL;
538 		}
539 
540 		pdsm = (enum papr_pdsm)nd_cmd->nd_command;
541 
542 		/* Verify if the pdsm command is valid */
543 		if (pdsm <= PAPR_PDSM_MIN || pdsm >= PAPR_PDSM_MAX) {
544 			dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid PDSM\n",
545 				pdsm);
546 			return -EINVAL;
547 		}
548 
549 		/* Have enough space to hold returned 'nd_pkg_pdsm' header */
550 		if (nd_cmd->nd_size_out < ND_PDSM_HDR_SIZE) {
551 			dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid payload\n",
552 				pdsm);
553 			return -EINVAL;
554 		}
555 	}
556 
557 	/* Let the command be further processed */
558 	return 0;
559 }
560 
561 static int papr_pdsm_fuel_gauge(struct papr_scm_priv *p,
562 				union nd_pdsm_payload *payload)
563 {
564 	int rc, size;
565 	u64 statval;
566 	struct papr_scm_perf_stat *stat;
567 	struct papr_scm_perf_stats *stats;
568 
569 	/* Silently fail if fetching performance metrics isn't  supported */
570 	if (!p->stat_buffer_len)
571 		return 0;
572 
573 	/* Allocate request buffer enough to hold single performance stat */
574 	size = sizeof(struct papr_scm_perf_stats) +
575 		sizeof(struct papr_scm_perf_stat);
576 
577 	stats = kzalloc(size, GFP_KERNEL);
578 	if (!stats)
579 		return -ENOMEM;
580 
581 	stat = &stats->scm_statistic[0];
582 	memcpy(&stat->stat_id, "MemLife ", sizeof(stat->stat_id));
583 	stat->stat_val = 0;
584 
585 	/* Fetch the fuel gauge and populate it in payload */
586 	rc = drc_pmem_query_stats(p, stats, 1);
587 	if (rc < 0) {
588 		dev_dbg(&p->pdev->dev, "Err(%d) fetching fuel gauge\n", rc);
589 		goto free_stats;
590 	}
591 
592 	statval = be64_to_cpu(stat->stat_val);
593 	dev_dbg(&p->pdev->dev,
594 		"Fetched fuel-gauge %llu", statval);
595 	payload->health.extension_flags |=
596 		PDSM_DIMM_HEALTH_RUN_GAUGE_VALID;
597 	payload->health.dimm_fuel_gauge = statval;
598 
599 	rc = sizeof(struct nd_papr_pdsm_health);
600 
601 free_stats:
602 	kfree(stats);
603 	return rc;
604 }
605 
606 /* Fetch the DIMM health info and populate it in provided package. */
607 static int papr_pdsm_health(struct papr_scm_priv *p,
608 			    union nd_pdsm_payload *payload)
609 {
610 	int rc;
611 
612 	/* Ensure dimm health mutex is taken preventing concurrent access */
613 	rc = mutex_lock_interruptible(&p->health_mutex);
614 	if (rc)
615 		goto out;
616 
617 	/* Always fetch upto date dimm health data ignoring cached values */
618 	rc = __drc_pmem_query_health(p);
619 	if (rc) {
620 		mutex_unlock(&p->health_mutex);
621 		goto out;
622 	}
623 
624 	/* update health struct with various flags derived from health bitmap */
625 	payload->health = (struct nd_papr_pdsm_health) {
626 		.extension_flags = 0,
627 		.dimm_unarmed = !!(p->health_bitmap & PAPR_PMEM_UNARMED_MASK),
628 		.dimm_bad_shutdown = !!(p->health_bitmap & PAPR_PMEM_BAD_SHUTDOWN_MASK),
629 		.dimm_bad_restore = !!(p->health_bitmap & PAPR_PMEM_BAD_RESTORE_MASK),
630 		.dimm_scrubbed = !!(p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED),
631 		.dimm_locked = !!(p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED),
632 		.dimm_encrypted = !!(p->health_bitmap & PAPR_PMEM_ENCRYPTED),
633 		.dimm_health = PAPR_PDSM_DIMM_HEALTHY,
634 	};
635 
636 	/* Update field dimm_health based on health_bitmap flags */
637 	if (p->health_bitmap & PAPR_PMEM_HEALTH_FATAL)
638 		payload->health.dimm_health = PAPR_PDSM_DIMM_FATAL;
639 	else if (p->health_bitmap & PAPR_PMEM_HEALTH_CRITICAL)
640 		payload->health.dimm_health = PAPR_PDSM_DIMM_CRITICAL;
641 	else if (p->health_bitmap & PAPR_PMEM_HEALTH_UNHEALTHY)
642 		payload->health.dimm_health = PAPR_PDSM_DIMM_UNHEALTHY;
643 
644 	/* struct populated hence can release the mutex now */
645 	mutex_unlock(&p->health_mutex);
646 
647 	/* Populate the fuel gauge meter in the payload */
648 	papr_pdsm_fuel_gauge(p, payload);
649 
650 	rc = sizeof(struct nd_papr_pdsm_health);
651 
652 out:
653 	return rc;
654 }
655 
656 /*
657  * 'struct pdsm_cmd_desc'
658  * Identifies supported PDSMs' expected length of in/out payloads
659  * and pdsm service function.
660  *
661  * size_in	: Size of input payload if any in the PDSM request.
662  * size_out	: Size of output payload if any in the PDSM request.
663  * service	: Service function for the PDSM request. Return semantics:
664  *		  rc < 0 : Error servicing PDSM and rc indicates the error.
665  *		  rc >=0 : Serviced successfully and 'rc' indicate number of
666  *			bytes written to payload.
667  */
668 struct pdsm_cmd_desc {
669 	u32 size_in;
670 	u32 size_out;
671 	int (*service)(struct papr_scm_priv *dimm,
672 		       union nd_pdsm_payload *payload);
673 };
674 
675 /* Holds all supported PDSMs' command descriptors */
676 static const struct pdsm_cmd_desc __pdsm_cmd_descriptors[] = {
677 	[PAPR_PDSM_MIN] = {
678 		.size_in = 0,
679 		.size_out = 0,
680 		.service = NULL,
681 	},
682 	/* New PDSM command descriptors to be added below */
683 
684 	[PAPR_PDSM_HEALTH] = {
685 		.size_in = 0,
686 		.size_out = sizeof(struct nd_papr_pdsm_health),
687 		.service = papr_pdsm_health,
688 	},
689 	/* Empty */
690 	[PAPR_PDSM_MAX] = {
691 		.size_in = 0,
692 		.size_out = 0,
693 		.service = NULL,
694 	},
695 };
696 
697 /* Given a valid pdsm cmd return its command descriptor else return NULL */
698 static inline const struct pdsm_cmd_desc *pdsm_cmd_desc(enum papr_pdsm cmd)
699 {
700 	if (cmd >= 0 || cmd < ARRAY_SIZE(__pdsm_cmd_descriptors))
701 		return &__pdsm_cmd_descriptors[cmd];
702 
703 	return NULL;
704 }
705 
706 /*
707  * For a given pdsm request call an appropriate service function.
708  * Returns errors if any while handling the pdsm command package.
709  */
710 static int papr_scm_service_pdsm(struct papr_scm_priv *p,
711 				 struct nd_cmd_pkg *pkg)
712 {
713 	/* Get the PDSM header and PDSM command */
714 	struct nd_pkg_pdsm *pdsm_pkg = (struct nd_pkg_pdsm *)pkg->nd_payload;
715 	enum papr_pdsm pdsm = (enum papr_pdsm)pkg->nd_command;
716 	const struct pdsm_cmd_desc *pdsc;
717 	int rc;
718 
719 	/* Fetch corresponding pdsm descriptor for validation and servicing */
720 	pdsc = pdsm_cmd_desc(pdsm);
721 
722 	/* Validate pdsm descriptor */
723 	/* Ensure that reserved fields are 0 */
724 	if (pdsm_pkg->reserved[0] || pdsm_pkg->reserved[1]) {
725 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid reserved field\n",
726 			pdsm);
727 		return -EINVAL;
728 	}
729 
730 	/* If pdsm expects some input, then ensure that the size_in matches */
731 	if (pdsc->size_in &&
732 	    pkg->nd_size_in != (pdsc->size_in + ND_PDSM_HDR_SIZE)) {
733 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_in=%d\n",
734 			pdsm, pkg->nd_size_in);
735 		return -EINVAL;
736 	}
737 
738 	/* If pdsm wants to return data, then ensure that  size_out matches */
739 	if (pdsc->size_out &&
740 	    pkg->nd_size_out != (pdsc->size_out + ND_PDSM_HDR_SIZE)) {
741 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_out=%d\n",
742 			pdsm, pkg->nd_size_out);
743 		return -EINVAL;
744 	}
745 
746 	/* Service the pdsm */
747 	if (pdsc->service) {
748 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Servicing..\n", pdsm);
749 
750 		rc = pdsc->service(p, &pdsm_pkg->payload);
751 
752 		if (rc < 0) {
753 			/* error encountered while servicing pdsm */
754 			pdsm_pkg->cmd_status = rc;
755 			pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
756 		} else {
757 			/* pdsm serviced and 'rc' bytes written to payload */
758 			pdsm_pkg->cmd_status = 0;
759 			pkg->nd_fw_size = ND_PDSM_HDR_SIZE + rc;
760 		}
761 	} else {
762 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Unsupported PDSM request\n",
763 			pdsm);
764 		pdsm_pkg->cmd_status = -ENOENT;
765 		pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
766 	}
767 
768 	return pdsm_pkg->cmd_status;
769 }
770 
771 static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
772 			  struct nvdimm *nvdimm, unsigned int cmd, void *buf,
773 			  unsigned int buf_len, int *cmd_rc)
774 {
775 	struct nd_cmd_get_config_size *get_size_hdr;
776 	struct nd_cmd_pkg *call_pkg = NULL;
777 	struct papr_scm_priv *p;
778 	int rc;
779 
780 	rc = is_cmd_valid(nvdimm, cmd, buf, buf_len);
781 	if (rc) {
782 		pr_debug("Invalid cmd=0x%x. Err=%d\n", cmd, rc);
783 		return rc;
784 	}
785 
786 	/* Use a local variable in case cmd_rc pointer is NULL */
787 	if (!cmd_rc)
788 		cmd_rc = &rc;
789 
790 	p = nvdimm_provider_data(nvdimm);
791 
792 	switch (cmd) {
793 	case ND_CMD_GET_CONFIG_SIZE:
794 		get_size_hdr = buf;
795 
796 		get_size_hdr->status = 0;
797 		get_size_hdr->max_xfer = 8;
798 		get_size_hdr->config_size = p->metadata_size;
799 		*cmd_rc = 0;
800 		break;
801 
802 	case ND_CMD_GET_CONFIG_DATA:
803 		*cmd_rc = papr_scm_meta_get(p, buf);
804 		break;
805 
806 	case ND_CMD_SET_CONFIG_DATA:
807 		*cmd_rc = papr_scm_meta_set(p, buf);
808 		break;
809 
810 	case ND_CMD_CALL:
811 		call_pkg = (struct nd_cmd_pkg *)buf;
812 		*cmd_rc = papr_scm_service_pdsm(p, call_pkg);
813 		break;
814 
815 	default:
816 		dev_dbg(&p->pdev->dev, "Unknown command = %d\n", cmd);
817 		return -EINVAL;
818 	}
819 
820 	dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);
821 
822 	return 0;
823 }
824 
825 static ssize_t perf_stats_show(struct device *dev,
826 			       struct device_attribute *attr, char *buf)
827 {
828 	int index;
829 	ssize_t rc;
830 	struct seq_buf s;
831 	struct papr_scm_perf_stat *stat;
832 	struct papr_scm_perf_stats *stats;
833 	struct nvdimm *dimm = to_nvdimm(dev);
834 	struct papr_scm_priv *p = nvdimm_provider_data(dimm);
835 
836 	if (!p->stat_buffer_len)
837 		return -ENOENT;
838 
839 	/* Allocate the buffer for phyp where stats are written */
840 	stats = kzalloc(p->stat_buffer_len, GFP_KERNEL);
841 	if (!stats)
842 		return -ENOMEM;
843 
844 	/* Ask phyp to return all dimm perf stats */
845 	rc = drc_pmem_query_stats(p, stats, 0);
846 	if (rc)
847 		goto free_stats;
848 	/*
849 	 * Go through the returned output buffer and print stats and
850 	 * values. Since stat_id is essentially a char string of
851 	 * 8 bytes, simply use the string format specifier to print it.
852 	 */
853 	seq_buf_init(&s, buf, PAGE_SIZE);
854 	for (index = 0, stat = stats->scm_statistic;
855 	     index < be32_to_cpu(stats->num_statistics);
856 	     ++index, ++stat) {
857 		seq_buf_printf(&s, "%.8s = 0x%016llX\n",
858 			       stat->stat_id,
859 			       be64_to_cpu(stat->stat_val));
860 	}
861 
862 free_stats:
863 	kfree(stats);
864 	return rc ? rc : (ssize_t)seq_buf_used(&s);
865 }
866 static DEVICE_ATTR_ADMIN_RO(perf_stats);
867 
868 static ssize_t flags_show(struct device *dev,
869 			  struct device_attribute *attr, char *buf)
870 {
871 	struct nvdimm *dimm = to_nvdimm(dev);
872 	struct papr_scm_priv *p = nvdimm_provider_data(dimm);
873 	struct seq_buf s;
874 	u64 health;
875 	int rc;
876 
877 	rc = drc_pmem_query_health(p);
878 	if (rc)
879 		return rc;
880 
881 	/* Copy health_bitmap locally, check masks & update out buffer */
882 	health = READ_ONCE(p->health_bitmap);
883 
884 	seq_buf_init(&s, buf, PAGE_SIZE);
885 	if (health & PAPR_PMEM_UNARMED_MASK)
886 		seq_buf_printf(&s, "not_armed ");
887 
888 	if (health & PAPR_PMEM_BAD_SHUTDOWN_MASK)
889 		seq_buf_printf(&s, "flush_fail ");
890 
891 	if (health & PAPR_PMEM_BAD_RESTORE_MASK)
892 		seq_buf_printf(&s, "restore_fail ");
893 
894 	if (health & PAPR_PMEM_ENCRYPTED)
895 		seq_buf_printf(&s, "encrypted ");
896 
897 	if (health & PAPR_PMEM_SMART_EVENT_MASK)
898 		seq_buf_printf(&s, "smart_notify ");
899 
900 	if (health & PAPR_PMEM_SCRUBBED_AND_LOCKED)
901 		seq_buf_printf(&s, "scrubbed locked ");
902 
903 	if (seq_buf_used(&s))
904 		seq_buf_printf(&s, "\n");
905 
906 	return seq_buf_used(&s);
907 }
908 DEVICE_ATTR_RO(flags);
909 
910 /* papr_scm specific dimm attributes */
911 static struct attribute *papr_nd_attributes[] = {
912 	&dev_attr_flags.attr,
913 	&dev_attr_perf_stats.attr,
914 	NULL,
915 };
916 
917 static struct attribute_group papr_nd_attribute_group = {
918 	.name = "papr",
919 	.attrs = papr_nd_attributes,
920 };
921 
922 static const struct attribute_group *papr_nd_attr_groups[] = {
923 	&papr_nd_attribute_group,
924 	NULL,
925 };
926 
927 static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
928 {
929 	struct device *dev = &p->pdev->dev;
930 	struct nd_mapping_desc mapping;
931 	struct nd_region_desc ndr_desc;
932 	unsigned long dimm_flags;
933 	int target_nid, online_nid;
934 	ssize_t stat_size;
935 
936 	p->bus_desc.ndctl = papr_scm_ndctl;
937 	p->bus_desc.module = THIS_MODULE;
938 	p->bus_desc.of_node = p->pdev->dev.of_node;
939 	p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL);
940 
941 	/* Set the dimm command family mask to accept PDSMs */
942 	set_bit(NVDIMM_FAMILY_PAPR, &p->bus_desc.dimm_family_mask);
943 
944 	if (!p->bus_desc.provider_name)
945 		return -ENOMEM;
946 
947 	p->bus = nvdimm_bus_register(NULL, &p->bus_desc);
948 	if (!p->bus) {
949 		dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
950 		kfree(p->bus_desc.provider_name);
951 		return -ENXIO;
952 	}
953 
954 	dimm_flags = 0;
955 	set_bit(NDD_LABELING, &dimm_flags);
956 
957 	/*
958 	 * Check if the nvdimm is unarmed. No locking needed as we are still
959 	 * initializing. Ignore error encountered if any.
960 	 */
961 	__drc_pmem_query_health(p);
962 
963 	if (p->health_bitmap & PAPR_PMEM_UNARMED_MASK)
964 		set_bit(NDD_UNARMED, &dimm_flags);
965 
966 	p->nvdimm = nvdimm_create(p->bus, p, papr_nd_attr_groups,
967 				  dimm_flags, PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
968 	if (!p->nvdimm) {
969 		dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
970 		goto err;
971 	}
972 
973 	if (nvdimm_bus_check_dimm_count(p->bus, 1))
974 		goto err;
975 
976 	/* now add the region */
977 
978 	memset(&mapping, 0, sizeof(mapping));
979 	mapping.nvdimm = p->nvdimm;
980 	mapping.start = 0;
981 	mapping.size = p->blocks * p->block_size; // XXX: potential overflow?
982 
983 	memset(&ndr_desc, 0, sizeof(ndr_desc));
984 	target_nid = dev_to_node(&p->pdev->dev);
985 	online_nid = numa_map_to_online_node(target_nid);
986 	ndr_desc.numa_node = online_nid;
987 	ndr_desc.target_node = target_nid;
988 	ndr_desc.res = &p->res;
989 	ndr_desc.of_node = p->dn;
990 	ndr_desc.provider_data = p;
991 	ndr_desc.mapping = &mapping;
992 	ndr_desc.num_mappings = 1;
993 	ndr_desc.nd_set = &p->nd_set;
994 
995 	if (p->hcall_flush_required) {
996 		set_bit(ND_REGION_ASYNC, &ndr_desc.flags);
997 		ndr_desc.flush = papr_scm_pmem_flush;
998 	}
999 
1000 	if (p->is_volatile)
1001 		p->region = nvdimm_volatile_region_create(p->bus, &ndr_desc);
1002 	else {
1003 		set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags);
1004 		p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
1005 	}
1006 	if (!p->region) {
1007 		dev_err(dev, "Error registering region %pR from %pOF\n",
1008 				ndr_desc.res, p->dn);
1009 		goto err;
1010 	}
1011 	if (target_nid != online_nid)
1012 		dev_info(dev, "Region registered with target node %d and online node %d",
1013 			 target_nid, online_nid);
1014 
1015 	mutex_lock(&papr_ndr_lock);
1016 	list_add_tail(&p->region_list, &papr_nd_regions);
1017 	mutex_unlock(&papr_ndr_lock);
1018 
1019 	/* Try retriving the stat buffer and see if its supported */
1020 	stat_size = drc_pmem_query_stats(p, NULL, 0);
1021 	if (stat_size > 0) {
1022 		p->stat_buffer_len = stat_size;
1023 		dev_dbg(&p->pdev->dev, "Max perf-stat size %lu-bytes\n",
1024 			p->stat_buffer_len);
1025 	} else {
1026 		dev_info(&p->pdev->dev, "Dimm performance stats unavailable\n");
1027 	}
1028 
1029 	return 0;
1030 
1031 err:	nvdimm_bus_unregister(p->bus);
1032 	kfree(p->bus_desc.provider_name);
1033 	return -ENXIO;
1034 }
1035 
1036 static void papr_scm_add_badblock(struct nd_region *region,
1037 				  struct nvdimm_bus *bus, u64 phys_addr)
1038 {
1039 	u64 aligned_addr = ALIGN_DOWN(phys_addr, L1_CACHE_BYTES);
1040 
1041 	if (nvdimm_bus_add_badrange(bus, aligned_addr, L1_CACHE_BYTES)) {
1042 		pr_err("Bad block registration for 0x%llx failed\n", phys_addr);
1043 		return;
1044 	}
1045 
1046 	pr_debug("Add memory range (0x%llx - 0x%llx) as bad range\n",
1047 		 aligned_addr, aligned_addr + L1_CACHE_BYTES);
1048 
1049 	nvdimm_region_notify(region, NVDIMM_REVALIDATE_POISON);
1050 }
1051 
1052 static int handle_mce_ue(struct notifier_block *nb, unsigned long val,
1053 			 void *data)
1054 {
1055 	struct machine_check_event *evt = data;
1056 	struct papr_scm_priv *p;
1057 	u64 phys_addr;
1058 	bool found = false;
1059 
1060 	if (evt->error_type != MCE_ERROR_TYPE_UE)
1061 		return NOTIFY_DONE;
1062 
1063 	if (list_empty(&papr_nd_regions))
1064 		return NOTIFY_DONE;
1065 
1066 	/*
1067 	 * The physical address obtained here is PAGE_SIZE aligned, so get the
1068 	 * exact address from the effective address
1069 	 */
1070 	phys_addr = evt->u.ue_error.physical_address +
1071 			(evt->u.ue_error.effective_address & ~PAGE_MASK);
1072 
1073 	if (!evt->u.ue_error.physical_address_provided ||
1074 	    !is_zone_device_page(pfn_to_page(phys_addr >> PAGE_SHIFT)))
1075 		return NOTIFY_DONE;
1076 
1077 	/* mce notifier is called from a process context, so mutex is safe */
1078 	mutex_lock(&papr_ndr_lock);
1079 	list_for_each_entry(p, &papr_nd_regions, region_list) {
1080 		if (phys_addr >= p->res.start && phys_addr <= p->res.end) {
1081 			found = true;
1082 			break;
1083 		}
1084 	}
1085 
1086 	if (found)
1087 		papr_scm_add_badblock(p->region, p->bus, phys_addr);
1088 
1089 	mutex_unlock(&papr_ndr_lock);
1090 
1091 	return found ? NOTIFY_OK : NOTIFY_DONE;
1092 }
1093 
1094 static struct notifier_block mce_ue_nb = {
1095 	.notifier_call = handle_mce_ue
1096 };
1097 
1098 static int papr_scm_probe(struct platform_device *pdev)
1099 {
1100 	struct device_node *dn = pdev->dev.of_node;
1101 	u32 drc_index, metadata_size;
1102 	u64 blocks, block_size;
1103 	struct papr_scm_priv *p;
1104 	const char *uuid_str;
1105 	u64 uuid[2];
1106 	int rc;
1107 
1108 	/* check we have all the required DT properties */
1109 	if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) {
1110 		dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
1111 		return -ENODEV;
1112 	}
1113 
1114 	if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
1115 		dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
1116 		return -ENODEV;
1117 	}
1118 
1119 	if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
1120 		dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
1121 		return -ENODEV;
1122 	}
1123 
1124 	if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
1125 		dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
1126 		return -ENODEV;
1127 	}
1128 
1129 
1130 	p = kzalloc(sizeof(*p), GFP_KERNEL);
1131 	if (!p)
1132 		return -ENOMEM;
1133 
1134 	/* Initialize the dimm mutex */
1135 	mutex_init(&p->health_mutex);
1136 
1137 	/* optional DT properties */
1138 	of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);
1139 
1140 	p->dn = dn;
1141 	p->drc_index = drc_index;
1142 	p->block_size = block_size;
1143 	p->blocks = blocks;
1144 	p->is_volatile = !of_property_read_bool(dn, "ibm,cache-flush-required");
1145 	p->hcall_flush_required = of_property_read_bool(dn, "ibm,hcall-flush-required");
1146 
1147 	/* We just need to ensure that set cookies are unique across */
1148 	uuid_parse(uuid_str, (uuid_t *) uuid);
1149 	/*
1150 	 * cookie1 and cookie2 are not really little endian
1151 	 * we store a little endian representation of the
1152 	 * uuid str so that we can compare this with the label
1153 	 * area cookie irrespective of the endian config with which
1154 	 * the kernel is built.
1155 	 */
1156 	p->nd_set.cookie1 = cpu_to_le64(uuid[0]);
1157 	p->nd_set.cookie2 = cpu_to_le64(uuid[1]);
1158 
1159 	/* might be zero */
1160 	p->metadata_size = metadata_size;
1161 	p->pdev = pdev;
1162 
1163 	/* request the hypervisor to bind this region to somewhere in memory */
1164 	rc = drc_pmem_bind(p);
1165 
1166 	/* If phyp says drc memory still bound then force unbound and retry */
1167 	if (rc == H_OVERLAP)
1168 		rc = drc_pmem_query_n_bind(p);
1169 
1170 	if (rc != H_SUCCESS) {
1171 		dev_err(&p->pdev->dev, "bind err: %d\n", rc);
1172 		rc = -ENXIO;
1173 		goto err;
1174 	}
1175 
1176 	/* setup the resource for the newly bound range */
1177 	p->res.start = p->bound_addr;
1178 	p->res.end   = p->bound_addr + p->blocks * p->block_size - 1;
1179 	p->res.name  = pdev->name;
1180 	p->res.flags = IORESOURCE_MEM;
1181 
1182 	rc = papr_scm_nvdimm_init(p);
1183 	if (rc)
1184 		goto err2;
1185 
1186 	platform_set_drvdata(pdev, p);
1187 
1188 	return 0;
1189 
1190 err2:	drc_pmem_unbind(p);
1191 err:	kfree(p);
1192 	return rc;
1193 }
1194 
1195 static int papr_scm_remove(struct platform_device *pdev)
1196 {
1197 	struct papr_scm_priv *p = platform_get_drvdata(pdev);
1198 
1199 	mutex_lock(&papr_ndr_lock);
1200 	list_del(&p->region_list);
1201 	mutex_unlock(&papr_ndr_lock);
1202 
1203 	nvdimm_bus_unregister(p->bus);
1204 	drc_pmem_unbind(p);
1205 	kfree(p->bus_desc.provider_name);
1206 	kfree(p);
1207 
1208 	return 0;
1209 }
1210 
1211 static const struct of_device_id papr_scm_match[] = {
1212 	{ .compatible = "ibm,pmemory" },
1213 	{ .compatible = "ibm,pmemory-v2" },
1214 	{ },
1215 };
1216 
1217 static struct platform_driver papr_scm_driver = {
1218 	.probe = papr_scm_probe,
1219 	.remove = papr_scm_remove,
1220 	.driver = {
1221 		.name = "papr_scm",
1222 		.of_match_table = papr_scm_match,
1223 	},
1224 };
1225 
1226 static int __init papr_scm_init(void)
1227 {
1228 	int ret;
1229 
1230 	ret = platform_driver_register(&papr_scm_driver);
1231 	if (!ret)
1232 		mce_register_notifier(&mce_ue_nb);
1233 
1234 	return ret;
1235 }
1236 module_init(papr_scm_init);
1237 
1238 static void __exit papr_scm_exit(void)
1239 {
1240 	mce_unregister_notifier(&mce_ue_nb);
1241 	platform_driver_unregister(&papr_scm_driver);
1242 }
1243 module_exit(papr_scm_exit);
1244 
1245 MODULE_DEVICE_TABLE(of, papr_scm_match);
1246 MODULE_LICENSE("GPL");
1247 MODULE_AUTHOR("IBM Corporation");
1248