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 #include <asm/unaligned.h>
22 #include <linux/perf_event.h>
23 
24 #define BIND_ANY_ADDR (~0ul)
25 
26 #define PAPR_SCM_DIMM_CMD_MASK \
27 	((1ul << ND_CMD_GET_CONFIG_SIZE) | \
28 	 (1ul << ND_CMD_GET_CONFIG_DATA) | \
29 	 (1ul << ND_CMD_SET_CONFIG_DATA) | \
30 	 (1ul << ND_CMD_CALL))
31 
32 /* DIMM health bitmap indicators */
33 /* SCM device is unable to persist memory contents */
34 #define PAPR_PMEM_UNARMED                   (1ULL << (63 - 0))
35 /* SCM device failed to persist memory contents */
36 #define PAPR_PMEM_SHUTDOWN_DIRTY            (1ULL << (63 - 1))
37 /* SCM device contents are persisted from previous IPL */
38 #define PAPR_PMEM_SHUTDOWN_CLEAN            (1ULL << (63 - 2))
39 /* SCM device contents are not persisted from previous IPL */
40 #define PAPR_PMEM_EMPTY                     (1ULL << (63 - 3))
41 /* SCM device memory life remaining is critically low */
42 #define PAPR_PMEM_HEALTH_CRITICAL           (1ULL << (63 - 4))
43 /* SCM device will be garded off next IPL due to failure */
44 #define PAPR_PMEM_HEALTH_FATAL              (1ULL << (63 - 5))
45 /* SCM contents cannot persist due to current platform health status */
46 #define PAPR_PMEM_HEALTH_UNHEALTHY          (1ULL << (63 - 6))
47 /* SCM device is unable to persist memory contents in certain conditions */
48 #define PAPR_PMEM_HEALTH_NON_CRITICAL       (1ULL << (63 - 7))
49 /* SCM device is encrypted */
50 #define PAPR_PMEM_ENCRYPTED                 (1ULL << (63 - 8))
51 /* SCM device has been scrubbed and locked */
52 #define PAPR_PMEM_SCRUBBED_AND_LOCKED       (1ULL << (63 - 9))
53 
54 /* Bits status indicators for health bitmap indicating unarmed dimm */
55 #define PAPR_PMEM_UNARMED_MASK (PAPR_PMEM_UNARMED |		\
56 				PAPR_PMEM_HEALTH_UNHEALTHY)
57 
58 /* Bits status indicators for health bitmap indicating unflushed dimm */
59 #define PAPR_PMEM_BAD_SHUTDOWN_MASK (PAPR_PMEM_SHUTDOWN_DIRTY)
60 
61 /* Bits status indicators for health bitmap indicating unrestored dimm */
62 #define PAPR_PMEM_BAD_RESTORE_MASK  (PAPR_PMEM_EMPTY)
63 
64 /* Bit status indicators for smart event notification */
65 #define PAPR_PMEM_SMART_EVENT_MASK (PAPR_PMEM_HEALTH_CRITICAL | \
66 				    PAPR_PMEM_HEALTH_FATAL |	\
67 				    PAPR_PMEM_HEALTH_UNHEALTHY)
68 
69 #define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
70 #define PAPR_SCM_PERF_STATS_VERSION 0x1
71 
72 /* Struct holding a single performance metric */
73 struct papr_scm_perf_stat {
74 	u8 stat_id[8];
75 	__be64 stat_val;
76 } __packed;
77 
78 /* Struct exchanged between kernel and PHYP for fetching drc perf stats */
79 struct papr_scm_perf_stats {
80 	u8 eye_catcher[8];
81 	/* Should be PAPR_SCM_PERF_STATS_VERSION */
82 	__be32 stats_version;
83 	/* Number of stats following */
84 	__be32 num_statistics;
85 	/* zero or more performance matrics */
86 	struct papr_scm_perf_stat scm_statistic[];
87 } __packed;
88 
89 /* private struct associated with each region */
90 struct papr_scm_priv {
91 	struct platform_device *pdev;
92 	struct device_node *dn;
93 	uint32_t drc_index;
94 	uint64_t blocks;
95 	uint64_t block_size;
96 	int metadata_size;
97 	bool is_volatile;
98 	bool hcall_flush_required;
99 
100 	uint64_t bound_addr;
101 
102 	struct nvdimm_bus_descriptor bus_desc;
103 	struct nvdimm_bus *bus;
104 	struct nvdimm *nvdimm;
105 	struct resource res;
106 	struct nd_region *region;
107 	struct nd_interleave_set nd_set;
108 	struct list_head region_list;
109 
110 	/* Protect dimm health data from concurrent read/writes */
111 	struct mutex health_mutex;
112 
113 	/* Last time the health information of the dimm was updated */
114 	unsigned long lasthealth_jiffies;
115 
116 	/* Health information for the dimm */
117 	u64 health_bitmap;
118 
119 	/* Holds the last known dirty shutdown counter value */
120 	u64 dirty_shutdown_counter;
121 
122 	/* length of the stat buffer as expected by phyp */
123 	size_t stat_buffer_len;
124 
125 	/* The bits which needs to be overridden */
126 	u64 health_bitmap_inject_mask;
127 
128 	/* array to have event_code and stat_id mappings */
129 	u8 *nvdimm_events_map;
130 };
131 
132 static int papr_scm_pmem_flush(struct nd_region *nd_region,
133 			       struct bio *bio __maybe_unused)
134 {
135 	struct papr_scm_priv *p = nd_region_provider_data(nd_region);
136 	unsigned long ret_buf[PLPAR_HCALL_BUFSIZE], token = 0;
137 	long rc;
138 
139 	dev_dbg(&p->pdev->dev, "flush drc 0x%x", p->drc_index);
140 
141 	do {
142 		rc = plpar_hcall(H_SCM_FLUSH, ret_buf, p->drc_index, token);
143 		token = ret_buf[0];
144 
145 		/* Check if we are stalled for some time */
146 		if (H_IS_LONG_BUSY(rc)) {
147 			msleep(get_longbusy_msecs(rc));
148 			rc = H_BUSY;
149 		} else if (rc == H_BUSY) {
150 			cond_resched();
151 		}
152 	} while (rc == H_BUSY);
153 
154 	if (rc) {
155 		dev_err(&p->pdev->dev, "flush error: %ld", rc);
156 		rc = -EIO;
157 	} else {
158 		dev_dbg(&p->pdev->dev, "flush drc 0x%x complete", p->drc_index);
159 	}
160 
161 	return rc;
162 }
163 
164 static LIST_HEAD(papr_nd_regions);
165 static DEFINE_MUTEX(papr_ndr_lock);
166 
167 static int drc_pmem_bind(struct papr_scm_priv *p)
168 {
169 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
170 	uint64_t saved = 0;
171 	uint64_t token;
172 	int64_t rc;
173 
174 	/*
175 	 * When the hypervisor cannot map all the requested memory in a single
176 	 * hcall it returns H_BUSY and we call again with the token until
177 	 * we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
178 	 * leave the system in an undefined state, so we wait.
179 	 */
180 	token = 0;
181 
182 	do {
183 		rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
184 				p->blocks, BIND_ANY_ADDR, token);
185 		token = ret[0];
186 		if (!saved)
187 			saved = ret[1];
188 		cond_resched();
189 	} while (rc == H_BUSY);
190 
191 	if (rc)
192 		return rc;
193 
194 	p->bound_addr = saved;
195 	dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n",
196 		p->drc_index, (unsigned long)saved);
197 	return rc;
198 }
199 
200 static void drc_pmem_unbind(struct papr_scm_priv *p)
201 {
202 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
203 	uint64_t token = 0;
204 	int64_t rc;
205 
206 	dev_dbg(&p->pdev->dev, "unbind drc 0x%x\n", p->drc_index);
207 
208 	/* NB: unbind has the same retry requirements as drc_pmem_bind() */
209 	do {
210 
211 		/* Unbind of all SCM resources associated with drcIndex */
212 		rc = plpar_hcall(H_SCM_UNBIND_ALL, ret, H_UNBIND_SCOPE_DRC,
213 				 p->drc_index, token);
214 		token = ret[0];
215 
216 		/* Check if we are stalled for some time */
217 		if (H_IS_LONG_BUSY(rc)) {
218 			msleep(get_longbusy_msecs(rc));
219 			rc = H_BUSY;
220 		} else if (rc == H_BUSY) {
221 			cond_resched();
222 		}
223 
224 	} while (rc == H_BUSY);
225 
226 	if (rc)
227 		dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);
228 	else
229 		dev_dbg(&p->pdev->dev, "unbind drc 0x%x complete\n",
230 			p->drc_index);
231 
232 	return;
233 }
234 
235 static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
236 {
237 	unsigned long start_addr;
238 	unsigned long end_addr;
239 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
240 	int64_t rc;
241 
242 
243 	rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
244 			 p->drc_index, 0);
245 	if (rc)
246 		goto err_out;
247 	start_addr = ret[0];
248 
249 	/* Make sure the full region is bound. */
250 	rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
251 			 p->drc_index, p->blocks - 1);
252 	if (rc)
253 		goto err_out;
254 	end_addr = ret[0];
255 
256 	if ((end_addr - start_addr) != ((p->blocks - 1) * p->block_size))
257 		goto err_out;
258 
259 	p->bound_addr = start_addr;
260 	dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n", p->drc_index, start_addr);
261 	return rc;
262 
263 err_out:
264 	dev_info(&p->pdev->dev,
265 		 "Failed to query, trying an unbind followed by bind");
266 	drc_pmem_unbind(p);
267 	return drc_pmem_bind(p);
268 }
269 
270 /*
271  * Query the Dimm performance stats from PHYP and copy them (if returned) to
272  * provided struct papr_scm_perf_stats instance 'stats' that can hold atleast
273  * (num_stats + header) bytes.
274  * - If buff_stats == NULL the return value is the size in bytes of the buffer
275  * needed to hold all supported performance-statistics.
276  * - If buff_stats != NULL and num_stats == 0 then we copy all known
277  * performance-statistics to 'buff_stat' and expect to be large enough to
278  * hold them.
279  * - if buff_stats != NULL and num_stats > 0 then copy the requested
280  * performance-statistics to buff_stats.
281  */
282 static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p,
283 				    struct papr_scm_perf_stats *buff_stats,
284 				    unsigned int num_stats)
285 {
286 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
287 	size_t size;
288 	s64 rc;
289 
290 	/* Setup the out buffer */
291 	if (buff_stats) {
292 		memcpy(buff_stats->eye_catcher,
293 		       PAPR_SCM_PERF_STATS_EYECATCHER, 8);
294 		buff_stats->stats_version =
295 			cpu_to_be32(PAPR_SCM_PERF_STATS_VERSION);
296 		buff_stats->num_statistics =
297 			cpu_to_be32(num_stats);
298 
299 		/*
300 		 * Calculate the buffer size based on num-stats provided
301 		 * or use the prefetched max buffer length
302 		 */
303 		if (num_stats)
304 			/* Calculate size from the num_stats */
305 			size = sizeof(struct papr_scm_perf_stats) +
306 				num_stats * sizeof(struct papr_scm_perf_stat);
307 		else
308 			size = p->stat_buffer_len;
309 	} else {
310 		/* In case of no out buffer ignore the size */
311 		size = 0;
312 	}
313 
314 	/* Do the HCALL asking PHYP for info */
315 	rc = plpar_hcall(H_SCM_PERFORMANCE_STATS, ret, p->drc_index,
316 			 buff_stats ? virt_to_phys(buff_stats) : 0,
317 			 size);
318 
319 	/* Check if the error was due to an unknown stat-id */
320 	if (rc == H_PARTIAL) {
321 		dev_err(&p->pdev->dev,
322 			"Unknown performance stats, Err:0x%016lX\n", ret[0]);
323 		return -ENOENT;
324 	} else if (rc == H_AUTHORITY) {
325 		dev_info(&p->pdev->dev,
326 			 "Permission denied while accessing performance stats");
327 		return -EPERM;
328 	} else if (rc == H_UNSUPPORTED) {
329 		dev_dbg(&p->pdev->dev, "Performance stats unsupported\n");
330 		return -EOPNOTSUPP;
331 	} else if (rc != H_SUCCESS) {
332 		dev_err(&p->pdev->dev,
333 			"Failed to query performance stats, Err:%lld\n", rc);
334 		return -EIO;
335 
336 	} else if (!size) {
337 		/* Handle case where stat buffer size was requested */
338 		dev_dbg(&p->pdev->dev,
339 			"Performance stats size %ld\n", ret[0]);
340 		return ret[0];
341 	}
342 
343 	/* Successfully fetched the requested stats from phyp */
344 	dev_dbg(&p->pdev->dev,
345 		"Performance stats returned %d stats\n",
346 		be32_to_cpu(buff_stats->num_statistics));
347 	return 0;
348 }
349 
350 #ifdef CONFIG_PERF_EVENTS
351 #define to_nvdimm_pmu(_pmu)	container_of(_pmu, struct nvdimm_pmu, pmu)
352 
353 static int papr_scm_pmu_get_value(struct perf_event *event, struct device *dev, u64 *count)
354 {
355 	struct papr_scm_perf_stat *stat;
356 	struct papr_scm_perf_stats *stats;
357 	struct papr_scm_priv *p = dev_get_drvdata(dev);
358 	int rc, size;
359 
360 	/* Allocate request buffer enough to hold single performance stat */
361 	size = sizeof(struct papr_scm_perf_stats) +
362 		sizeof(struct papr_scm_perf_stat);
363 
364 	if (!p || !p->nvdimm_events_map)
365 		return -EINVAL;
366 
367 	stats = kzalloc(size, GFP_KERNEL);
368 	if (!stats)
369 		return -ENOMEM;
370 
371 	stat = &stats->scm_statistic[0];
372 	memcpy(&stat->stat_id,
373 	       &p->nvdimm_events_map[event->attr.config * sizeof(stat->stat_id)],
374 		sizeof(stat->stat_id));
375 	stat->stat_val = 0;
376 
377 	rc = drc_pmem_query_stats(p, stats, 1);
378 	if (rc < 0) {
379 		kfree(stats);
380 		return rc;
381 	}
382 
383 	*count = be64_to_cpu(stat->stat_val);
384 	kfree(stats);
385 	return 0;
386 }
387 
388 static int papr_scm_pmu_event_init(struct perf_event *event)
389 {
390 	struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
391 	struct papr_scm_priv *p;
392 
393 	if (!nd_pmu)
394 		return -EINVAL;
395 
396 	/* test the event attr type for PMU enumeration */
397 	if (event->attr.type != event->pmu->type)
398 		return -ENOENT;
399 
400 	/* it does not support event sampling mode */
401 	if (is_sampling_event(event))
402 		return -EOPNOTSUPP;
403 
404 	/* no branch sampling */
405 	if (has_branch_stack(event))
406 		return -EOPNOTSUPP;
407 
408 	p = (struct papr_scm_priv *)nd_pmu->dev->driver_data;
409 	if (!p)
410 		return -EINVAL;
411 
412 	/* Invalid eventcode */
413 	if (event->attr.config == 0 || event->attr.config > 16)
414 		return -EINVAL;
415 
416 	return 0;
417 }
418 
419 static int papr_scm_pmu_add(struct perf_event *event, int flags)
420 {
421 	u64 count;
422 	int rc;
423 	struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
424 
425 	if (!nd_pmu)
426 		return -EINVAL;
427 
428 	if (flags & PERF_EF_START) {
429 		rc = papr_scm_pmu_get_value(event, nd_pmu->dev, &count);
430 		if (rc)
431 			return rc;
432 
433 		local64_set(&event->hw.prev_count, count);
434 	}
435 
436 	return 0;
437 }
438 
439 static void papr_scm_pmu_read(struct perf_event *event)
440 {
441 	u64 prev, now;
442 	int rc;
443 	struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
444 
445 	if (!nd_pmu)
446 		return;
447 
448 	rc = papr_scm_pmu_get_value(event, nd_pmu->dev, &now);
449 	if (rc)
450 		return;
451 
452 	prev = local64_xchg(&event->hw.prev_count, now);
453 	local64_add(now - prev, &event->count);
454 }
455 
456 static void papr_scm_pmu_del(struct perf_event *event, int flags)
457 {
458 	papr_scm_pmu_read(event);
459 }
460 
461 static int papr_scm_pmu_check_events(struct papr_scm_priv *p, struct nvdimm_pmu *nd_pmu)
462 {
463 	struct papr_scm_perf_stat *stat;
464 	struct papr_scm_perf_stats *stats;
465 	u32 available_events;
466 	int index, rc = 0;
467 
468 	if (!p->stat_buffer_len)
469 		return -ENOENT;
470 
471 	available_events = (p->stat_buffer_len  - sizeof(struct papr_scm_perf_stats))
472 			/ sizeof(struct papr_scm_perf_stat);
473 	if (available_events == 0)
474 		return -EOPNOTSUPP;
475 
476 	/* Allocate the buffer for phyp where stats are written */
477 	stats = kzalloc(p->stat_buffer_len, GFP_KERNEL);
478 	if (!stats) {
479 		rc = -ENOMEM;
480 		return rc;
481 	}
482 
483 	/* Called to get list of events supported */
484 	rc = drc_pmem_query_stats(p, stats, 0);
485 	if (rc)
486 		goto out;
487 
488 	/*
489 	 * Allocate memory and populate nvdimm_event_map.
490 	 * Allocate an extra element for NULL entry
491 	 */
492 	p->nvdimm_events_map = kcalloc(available_events + 1,
493 				       sizeof(stat->stat_id),
494 				       GFP_KERNEL);
495 	if (!p->nvdimm_events_map) {
496 		rc = -ENOMEM;
497 		goto out;
498 	}
499 
500 	/* Copy all stat_ids to event map */
501 	for (index = 0, stat = stats->scm_statistic;
502 	     index < available_events; index++, ++stat) {
503 		memcpy(&p->nvdimm_events_map[index * sizeof(stat->stat_id)],
504 		       &stat->stat_id, sizeof(stat->stat_id));
505 	}
506 out:
507 	kfree(stats);
508 	return rc;
509 }
510 
511 static void papr_scm_pmu_register(struct papr_scm_priv *p)
512 {
513 	struct nvdimm_pmu *nd_pmu;
514 	int rc, nodeid;
515 
516 	nd_pmu = kzalloc(sizeof(*nd_pmu), GFP_KERNEL);
517 	if (!nd_pmu) {
518 		rc = -ENOMEM;
519 		goto pmu_err_print;
520 	}
521 
522 	rc = papr_scm_pmu_check_events(p, nd_pmu);
523 	if (rc)
524 		goto pmu_check_events_err;
525 
526 	nd_pmu->pmu.task_ctx_nr = perf_invalid_context;
527 	nd_pmu->pmu.name = nvdimm_name(p->nvdimm);
528 	nd_pmu->pmu.event_init = papr_scm_pmu_event_init;
529 	nd_pmu->pmu.read = papr_scm_pmu_read;
530 	nd_pmu->pmu.add = papr_scm_pmu_add;
531 	nd_pmu->pmu.del = papr_scm_pmu_del;
532 
533 	nd_pmu->pmu.capabilities = PERF_PMU_CAP_NO_INTERRUPT |
534 				PERF_PMU_CAP_NO_EXCLUDE;
535 
536 	/*updating the cpumask variable */
537 	nodeid = numa_map_to_online_node(dev_to_node(&p->pdev->dev));
538 	nd_pmu->arch_cpumask = *cpumask_of_node(nodeid);
539 
540 	rc = register_nvdimm_pmu(nd_pmu, p->pdev);
541 	if (rc)
542 		goto pmu_register_err;
543 
544 	/*
545 	 * Set archdata.priv value to nvdimm_pmu structure, to handle the
546 	 * unregistering of pmu device.
547 	 */
548 	p->pdev->archdata.priv = nd_pmu;
549 	return;
550 
551 pmu_register_err:
552 	kfree(p->nvdimm_events_map);
553 pmu_check_events_err:
554 	kfree(nd_pmu);
555 pmu_err_print:
556 	dev_info(&p->pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
557 }
558 
559 #else
560 static void papr_scm_pmu_register(struct papr_scm_priv *p) { }
561 #endif
562 
563 /*
564  * Issue hcall to retrieve dimm health info and populate papr_scm_priv with the
565  * health information.
566  */
567 static int __drc_pmem_query_health(struct papr_scm_priv *p)
568 {
569 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
570 	u64 bitmap = 0;
571 	long rc;
572 
573 	/* issue the hcall */
574 	rc = plpar_hcall(H_SCM_HEALTH, ret, p->drc_index);
575 	if (rc == H_SUCCESS)
576 		bitmap = ret[0] & ret[1];
577 	else if (rc == H_FUNCTION)
578 		dev_info_once(&p->pdev->dev,
579 			      "Hcall H_SCM_HEALTH not implemented, assuming empty health bitmap");
580 	else {
581 
582 		dev_err(&p->pdev->dev,
583 			"Failed to query health information, Err:%ld\n", rc);
584 		return -ENXIO;
585 	}
586 
587 	p->lasthealth_jiffies = jiffies;
588 	/* Allow injecting specific health bits via inject mask. */
589 	if (p->health_bitmap_inject_mask)
590 		bitmap = (bitmap & ~p->health_bitmap_inject_mask) |
591 			p->health_bitmap_inject_mask;
592 	WRITE_ONCE(p->health_bitmap, bitmap);
593 	dev_dbg(&p->pdev->dev,
594 		"Queried dimm health info. Bitmap:0x%016lx Mask:0x%016lx\n",
595 		ret[0], ret[1]);
596 
597 	return 0;
598 }
599 
600 /* Min interval in seconds for assuming stable dimm health */
601 #define MIN_HEALTH_QUERY_INTERVAL 60
602 
603 /* Query cached health info and if needed call drc_pmem_query_health */
604 static int drc_pmem_query_health(struct papr_scm_priv *p)
605 {
606 	unsigned long cache_timeout;
607 	int rc;
608 
609 	/* Protect concurrent modifications to papr_scm_priv */
610 	rc = mutex_lock_interruptible(&p->health_mutex);
611 	if (rc)
612 		return rc;
613 
614 	/* Jiffies offset for which the health data is assumed to be same */
615 	cache_timeout = p->lasthealth_jiffies +
616 		msecs_to_jiffies(MIN_HEALTH_QUERY_INTERVAL * 1000);
617 
618 	/* Fetch new health info is its older than MIN_HEALTH_QUERY_INTERVAL */
619 	if (time_after(jiffies, cache_timeout))
620 		rc = __drc_pmem_query_health(p);
621 	else
622 		/* Assume cached health data is valid */
623 		rc = 0;
624 
625 	mutex_unlock(&p->health_mutex);
626 	return rc;
627 }
628 
629 static int papr_scm_meta_get(struct papr_scm_priv *p,
630 			     struct nd_cmd_get_config_data_hdr *hdr)
631 {
632 	unsigned long data[PLPAR_HCALL_BUFSIZE];
633 	unsigned long offset, data_offset;
634 	int len, read;
635 	int64_t ret;
636 
637 	if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
638 		return -EINVAL;
639 
640 	for (len = hdr->in_length; len; len -= read) {
641 
642 		data_offset = hdr->in_length - len;
643 		offset = hdr->in_offset + data_offset;
644 
645 		if (len >= 8)
646 			read = 8;
647 		else if (len >= 4)
648 			read = 4;
649 		else if (len >= 2)
650 			read = 2;
651 		else
652 			read = 1;
653 
654 		ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
655 				  offset, read);
656 
657 		if (ret == H_PARAMETER) /* bad DRC index */
658 			return -ENODEV;
659 		if (ret)
660 			return -EINVAL; /* other invalid parameter */
661 
662 		switch (read) {
663 		case 8:
664 			*(uint64_t *)(hdr->out_buf + data_offset) = be64_to_cpu(data[0]);
665 			break;
666 		case 4:
667 			*(uint32_t *)(hdr->out_buf + data_offset) = be32_to_cpu(data[0] & 0xffffffff);
668 			break;
669 
670 		case 2:
671 			*(uint16_t *)(hdr->out_buf + data_offset) = be16_to_cpu(data[0] & 0xffff);
672 			break;
673 
674 		case 1:
675 			*(uint8_t *)(hdr->out_buf + data_offset) = (data[0] & 0xff);
676 			break;
677 		}
678 	}
679 	return 0;
680 }
681 
682 static int papr_scm_meta_set(struct papr_scm_priv *p,
683 			     struct nd_cmd_set_config_hdr *hdr)
684 {
685 	unsigned long offset, data_offset;
686 	int len, wrote;
687 	unsigned long data;
688 	__be64 data_be;
689 	int64_t ret;
690 
691 	if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
692 		return -EINVAL;
693 
694 	for (len = hdr->in_length; len; len -= wrote) {
695 
696 		data_offset = hdr->in_length - len;
697 		offset = hdr->in_offset + data_offset;
698 
699 		if (len >= 8) {
700 			data = *(uint64_t *)(hdr->in_buf + data_offset);
701 			data_be = cpu_to_be64(data);
702 			wrote = 8;
703 		} else if (len >= 4) {
704 			data = *(uint32_t *)(hdr->in_buf + data_offset);
705 			data &= 0xffffffff;
706 			data_be = cpu_to_be32(data);
707 			wrote = 4;
708 		} else if (len >= 2) {
709 			data = *(uint16_t *)(hdr->in_buf + data_offset);
710 			data &= 0xffff;
711 			data_be = cpu_to_be16(data);
712 			wrote = 2;
713 		} else {
714 			data_be = *(uint8_t *)(hdr->in_buf + data_offset);
715 			data_be &= 0xff;
716 			wrote = 1;
717 		}
718 
719 		ret = plpar_hcall_norets(H_SCM_WRITE_METADATA, p->drc_index,
720 					 offset, data_be, wrote);
721 		if (ret == H_PARAMETER) /* bad DRC index */
722 			return -ENODEV;
723 		if (ret)
724 			return -EINVAL; /* other invalid parameter */
725 	}
726 
727 	return 0;
728 }
729 
730 /*
731  * Do a sanity checks on the inputs args to dimm-control function and return
732  * '0' if valid. Validation of PDSM payloads happens later in
733  * papr_scm_service_pdsm.
734  */
735 static int is_cmd_valid(struct nvdimm *nvdimm, unsigned int cmd, void *buf,
736 			unsigned int buf_len)
737 {
738 	unsigned long cmd_mask = PAPR_SCM_DIMM_CMD_MASK;
739 	struct nd_cmd_pkg *nd_cmd;
740 	struct papr_scm_priv *p;
741 	enum papr_pdsm pdsm;
742 
743 	/* Only dimm-specific calls are supported atm */
744 	if (!nvdimm)
745 		return -EINVAL;
746 
747 	/* get the provider data from struct nvdimm */
748 	p = nvdimm_provider_data(nvdimm);
749 
750 	if (!test_bit(cmd, &cmd_mask)) {
751 		dev_dbg(&p->pdev->dev, "Unsupported cmd=%u\n", cmd);
752 		return -EINVAL;
753 	}
754 
755 	/* For CMD_CALL verify pdsm request */
756 	if (cmd == ND_CMD_CALL) {
757 		/* Verify the envelope and envelop size */
758 		if (!buf ||
759 		    buf_len < (sizeof(struct nd_cmd_pkg) + ND_PDSM_HDR_SIZE)) {
760 			dev_dbg(&p->pdev->dev, "Invalid pkg size=%u\n",
761 				buf_len);
762 			return -EINVAL;
763 		}
764 
765 		/* Verify that the nd_cmd_pkg.nd_family is correct */
766 		nd_cmd = (struct nd_cmd_pkg *)buf;
767 
768 		if (nd_cmd->nd_family != NVDIMM_FAMILY_PAPR) {
769 			dev_dbg(&p->pdev->dev, "Invalid pkg family=0x%llx\n",
770 				nd_cmd->nd_family);
771 			return -EINVAL;
772 		}
773 
774 		pdsm = (enum papr_pdsm)nd_cmd->nd_command;
775 
776 		/* Verify if the pdsm command is valid */
777 		if (pdsm <= PAPR_PDSM_MIN || pdsm >= PAPR_PDSM_MAX) {
778 			dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid PDSM\n",
779 				pdsm);
780 			return -EINVAL;
781 		}
782 
783 		/* Have enough space to hold returned 'nd_pkg_pdsm' header */
784 		if (nd_cmd->nd_size_out < ND_PDSM_HDR_SIZE) {
785 			dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid payload\n",
786 				pdsm);
787 			return -EINVAL;
788 		}
789 	}
790 
791 	/* Let the command be further processed */
792 	return 0;
793 }
794 
795 static int papr_pdsm_fuel_gauge(struct papr_scm_priv *p,
796 				union nd_pdsm_payload *payload)
797 {
798 	int rc, size;
799 	u64 statval;
800 	struct papr_scm_perf_stat *stat;
801 	struct papr_scm_perf_stats *stats;
802 
803 	/* Silently fail if fetching performance metrics isn't  supported */
804 	if (!p->stat_buffer_len)
805 		return 0;
806 
807 	/* Allocate request buffer enough to hold single performance stat */
808 	size = sizeof(struct papr_scm_perf_stats) +
809 		sizeof(struct papr_scm_perf_stat);
810 
811 	stats = kzalloc(size, GFP_KERNEL);
812 	if (!stats)
813 		return -ENOMEM;
814 
815 	stat = &stats->scm_statistic[0];
816 	memcpy(&stat->stat_id, "MemLife ", sizeof(stat->stat_id));
817 	stat->stat_val = 0;
818 
819 	/* Fetch the fuel gauge and populate it in payload */
820 	rc = drc_pmem_query_stats(p, stats, 1);
821 	if (rc < 0) {
822 		dev_dbg(&p->pdev->dev, "Err(%d) fetching fuel gauge\n", rc);
823 		goto free_stats;
824 	}
825 
826 	statval = be64_to_cpu(stat->stat_val);
827 	dev_dbg(&p->pdev->dev,
828 		"Fetched fuel-gauge %llu", statval);
829 	payload->health.extension_flags |=
830 		PDSM_DIMM_HEALTH_RUN_GAUGE_VALID;
831 	payload->health.dimm_fuel_gauge = statval;
832 
833 	rc = sizeof(struct nd_papr_pdsm_health);
834 
835 free_stats:
836 	kfree(stats);
837 	return rc;
838 }
839 
840 /* Add the dirty-shutdown-counter value to the pdsm */
841 static int papr_pdsm_dsc(struct papr_scm_priv *p,
842 			 union nd_pdsm_payload *payload)
843 {
844 	payload->health.extension_flags |= PDSM_DIMM_DSC_VALID;
845 	payload->health.dimm_dsc = p->dirty_shutdown_counter;
846 
847 	return sizeof(struct nd_papr_pdsm_health);
848 }
849 
850 /* Fetch the DIMM health info and populate it in provided package. */
851 static int papr_pdsm_health(struct papr_scm_priv *p,
852 			    union nd_pdsm_payload *payload)
853 {
854 	int rc;
855 
856 	/* Ensure dimm health mutex is taken preventing concurrent access */
857 	rc = mutex_lock_interruptible(&p->health_mutex);
858 	if (rc)
859 		goto out;
860 
861 	/* Always fetch upto date dimm health data ignoring cached values */
862 	rc = __drc_pmem_query_health(p);
863 	if (rc) {
864 		mutex_unlock(&p->health_mutex);
865 		goto out;
866 	}
867 
868 	/* update health struct with various flags derived from health bitmap */
869 	payload->health = (struct nd_papr_pdsm_health) {
870 		.extension_flags = 0,
871 		.dimm_unarmed = !!(p->health_bitmap & PAPR_PMEM_UNARMED_MASK),
872 		.dimm_bad_shutdown = !!(p->health_bitmap & PAPR_PMEM_BAD_SHUTDOWN_MASK),
873 		.dimm_bad_restore = !!(p->health_bitmap & PAPR_PMEM_BAD_RESTORE_MASK),
874 		.dimm_scrubbed = !!(p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED),
875 		.dimm_locked = !!(p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED),
876 		.dimm_encrypted = !!(p->health_bitmap & PAPR_PMEM_ENCRYPTED),
877 		.dimm_health = PAPR_PDSM_DIMM_HEALTHY,
878 	};
879 
880 	/* Update field dimm_health based on health_bitmap flags */
881 	if (p->health_bitmap & PAPR_PMEM_HEALTH_FATAL)
882 		payload->health.dimm_health = PAPR_PDSM_DIMM_FATAL;
883 	else if (p->health_bitmap & PAPR_PMEM_HEALTH_CRITICAL)
884 		payload->health.dimm_health = PAPR_PDSM_DIMM_CRITICAL;
885 	else if (p->health_bitmap & PAPR_PMEM_HEALTH_UNHEALTHY)
886 		payload->health.dimm_health = PAPR_PDSM_DIMM_UNHEALTHY;
887 
888 	/* struct populated hence can release the mutex now */
889 	mutex_unlock(&p->health_mutex);
890 
891 	/* Populate the fuel gauge meter in the payload */
892 	papr_pdsm_fuel_gauge(p, payload);
893 	/* Populate the dirty-shutdown-counter field */
894 	papr_pdsm_dsc(p, payload);
895 
896 	rc = sizeof(struct nd_papr_pdsm_health);
897 
898 out:
899 	return rc;
900 }
901 
902 /* Inject a smart error Add the dirty-shutdown-counter value to the pdsm */
903 static int papr_pdsm_smart_inject(struct papr_scm_priv *p,
904 				  union nd_pdsm_payload *payload)
905 {
906 	int rc;
907 	u32 supported_flags = 0;
908 	u64 inject_mask = 0, clear_mask = 0;
909 	u64 mask;
910 
911 	/* Check for individual smart error flags and update inject/clear masks */
912 	if (payload->smart_inject.flags & PDSM_SMART_INJECT_HEALTH_FATAL) {
913 		supported_flags |= PDSM_SMART_INJECT_HEALTH_FATAL;
914 		if (payload->smart_inject.fatal_enable)
915 			inject_mask |= PAPR_PMEM_HEALTH_FATAL;
916 		else
917 			clear_mask |= PAPR_PMEM_HEALTH_FATAL;
918 	}
919 
920 	if (payload->smart_inject.flags & PDSM_SMART_INJECT_BAD_SHUTDOWN) {
921 		supported_flags |= PDSM_SMART_INJECT_BAD_SHUTDOWN;
922 		if (payload->smart_inject.unsafe_shutdown_enable)
923 			inject_mask |= PAPR_PMEM_SHUTDOWN_DIRTY;
924 		else
925 			clear_mask |= PAPR_PMEM_SHUTDOWN_DIRTY;
926 	}
927 
928 	dev_dbg(&p->pdev->dev, "[Smart-inject] inject_mask=%#llx clear_mask=%#llx\n",
929 		inject_mask, clear_mask);
930 
931 	/* Prevent concurrent access to dimm health bitmap related members */
932 	rc = mutex_lock_interruptible(&p->health_mutex);
933 	if (rc)
934 		return rc;
935 
936 	/* Use inject/clear masks to set health_bitmap_inject_mask */
937 	mask = READ_ONCE(p->health_bitmap_inject_mask);
938 	mask = (mask & ~clear_mask) | inject_mask;
939 	WRITE_ONCE(p->health_bitmap_inject_mask, mask);
940 
941 	/* Invalidate cached health bitmap */
942 	p->lasthealth_jiffies = 0;
943 
944 	mutex_unlock(&p->health_mutex);
945 
946 	/* Return the supported flags back to userspace */
947 	payload->smart_inject.flags = supported_flags;
948 
949 	return sizeof(struct nd_papr_pdsm_health);
950 }
951 
952 /*
953  * 'struct pdsm_cmd_desc'
954  * Identifies supported PDSMs' expected length of in/out payloads
955  * and pdsm service function.
956  *
957  * size_in	: Size of input payload if any in the PDSM request.
958  * size_out	: Size of output payload if any in the PDSM request.
959  * service	: Service function for the PDSM request. Return semantics:
960  *		  rc < 0 : Error servicing PDSM and rc indicates the error.
961  *		  rc >=0 : Serviced successfully and 'rc' indicate number of
962  *			bytes written to payload.
963  */
964 struct pdsm_cmd_desc {
965 	u32 size_in;
966 	u32 size_out;
967 	int (*service)(struct papr_scm_priv *dimm,
968 		       union nd_pdsm_payload *payload);
969 };
970 
971 /* Holds all supported PDSMs' command descriptors */
972 static const struct pdsm_cmd_desc __pdsm_cmd_descriptors[] = {
973 	[PAPR_PDSM_MIN] = {
974 		.size_in = 0,
975 		.size_out = 0,
976 		.service = NULL,
977 	},
978 	/* New PDSM command descriptors to be added below */
979 
980 	[PAPR_PDSM_HEALTH] = {
981 		.size_in = 0,
982 		.size_out = sizeof(struct nd_papr_pdsm_health),
983 		.service = papr_pdsm_health,
984 	},
985 
986 	[PAPR_PDSM_SMART_INJECT] = {
987 		.size_in = sizeof(struct nd_papr_pdsm_smart_inject),
988 		.size_out = sizeof(struct nd_papr_pdsm_smart_inject),
989 		.service = papr_pdsm_smart_inject,
990 	},
991 	/* Empty */
992 	[PAPR_PDSM_MAX] = {
993 		.size_in = 0,
994 		.size_out = 0,
995 		.service = NULL,
996 	},
997 };
998 
999 /* Given a valid pdsm cmd return its command descriptor else return NULL */
1000 static inline const struct pdsm_cmd_desc *pdsm_cmd_desc(enum papr_pdsm cmd)
1001 {
1002 	if (cmd >= 0 || cmd < ARRAY_SIZE(__pdsm_cmd_descriptors))
1003 		return &__pdsm_cmd_descriptors[cmd];
1004 
1005 	return NULL;
1006 }
1007 
1008 /*
1009  * For a given pdsm request call an appropriate service function.
1010  * Returns errors if any while handling the pdsm command package.
1011  */
1012 static int papr_scm_service_pdsm(struct papr_scm_priv *p,
1013 				 struct nd_cmd_pkg *pkg)
1014 {
1015 	/* Get the PDSM header and PDSM command */
1016 	struct nd_pkg_pdsm *pdsm_pkg = (struct nd_pkg_pdsm *)pkg->nd_payload;
1017 	enum papr_pdsm pdsm = (enum papr_pdsm)pkg->nd_command;
1018 	const struct pdsm_cmd_desc *pdsc;
1019 	int rc;
1020 
1021 	/* Fetch corresponding pdsm descriptor for validation and servicing */
1022 	pdsc = pdsm_cmd_desc(pdsm);
1023 
1024 	/* Validate pdsm descriptor */
1025 	/* Ensure that reserved fields are 0 */
1026 	if (pdsm_pkg->reserved[0] || pdsm_pkg->reserved[1]) {
1027 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid reserved field\n",
1028 			pdsm);
1029 		return -EINVAL;
1030 	}
1031 
1032 	/* If pdsm expects some input, then ensure that the size_in matches */
1033 	if (pdsc->size_in &&
1034 	    pkg->nd_size_in != (pdsc->size_in + ND_PDSM_HDR_SIZE)) {
1035 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_in=%d\n",
1036 			pdsm, pkg->nd_size_in);
1037 		return -EINVAL;
1038 	}
1039 
1040 	/* If pdsm wants to return data, then ensure that  size_out matches */
1041 	if (pdsc->size_out &&
1042 	    pkg->nd_size_out != (pdsc->size_out + ND_PDSM_HDR_SIZE)) {
1043 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_out=%d\n",
1044 			pdsm, pkg->nd_size_out);
1045 		return -EINVAL;
1046 	}
1047 
1048 	/* Service the pdsm */
1049 	if (pdsc->service) {
1050 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Servicing..\n", pdsm);
1051 
1052 		rc = pdsc->service(p, &pdsm_pkg->payload);
1053 
1054 		if (rc < 0) {
1055 			/* error encountered while servicing pdsm */
1056 			pdsm_pkg->cmd_status = rc;
1057 			pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
1058 		} else {
1059 			/* pdsm serviced and 'rc' bytes written to payload */
1060 			pdsm_pkg->cmd_status = 0;
1061 			pkg->nd_fw_size = ND_PDSM_HDR_SIZE + rc;
1062 		}
1063 	} else {
1064 		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Unsupported PDSM request\n",
1065 			pdsm);
1066 		pdsm_pkg->cmd_status = -ENOENT;
1067 		pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
1068 	}
1069 
1070 	return pdsm_pkg->cmd_status;
1071 }
1072 
1073 static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
1074 			  struct nvdimm *nvdimm, unsigned int cmd, void *buf,
1075 			  unsigned int buf_len, int *cmd_rc)
1076 {
1077 	struct nd_cmd_get_config_size *get_size_hdr;
1078 	struct nd_cmd_pkg *call_pkg = NULL;
1079 	struct papr_scm_priv *p;
1080 	int rc;
1081 
1082 	rc = is_cmd_valid(nvdimm, cmd, buf, buf_len);
1083 	if (rc) {
1084 		pr_debug("Invalid cmd=0x%x. Err=%d\n", cmd, rc);
1085 		return rc;
1086 	}
1087 
1088 	/* Use a local variable in case cmd_rc pointer is NULL */
1089 	if (!cmd_rc)
1090 		cmd_rc = &rc;
1091 
1092 	p = nvdimm_provider_data(nvdimm);
1093 
1094 	switch (cmd) {
1095 	case ND_CMD_GET_CONFIG_SIZE:
1096 		get_size_hdr = buf;
1097 
1098 		get_size_hdr->status = 0;
1099 		get_size_hdr->max_xfer = 8;
1100 		get_size_hdr->config_size = p->metadata_size;
1101 		*cmd_rc = 0;
1102 		break;
1103 
1104 	case ND_CMD_GET_CONFIG_DATA:
1105 		*cmd_rc = papr_scm_meta_get(p, buf);
1106 		break;
1107 
1108 	case ND_CMD_SET_CONFIG_DATA:
1109 		*cmd_rc = papr_scm_meta_set(p, buf);
1110 		break;
1111 
1112 	case ND_CMD_CALL:
1113 		call_pkg = (struct nd_cmd_pkg *)buf;
1114 		*cmd_rc = papr_scm_service_pdsm(p, call_pkg);
1115 		break;
1116 
1117 	default:
1118 		dev_dbg(&p->pdev->dev, "Unknown command = %d\n", cmd);
1119 		return -EINVAL;
1120 	}
1121 
1122 	dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);
1123 
1124 	return 0;
1125 }
1126 
1127 static ssize_t health_bitmap_inject_show(struct device *dev,
1128 					 struct device_attribute *attr,
1129 					 char *buf)
1130 {
1131 	struct nvdimm *dimm = to_nvdimm(dev);
1132 	struct papr_scm_priv *p = nvdimm_provider_data(dimm);
1133 
1134 	return sprintf(buf, "%#llx\n",
1135 		       READ_ONCE(p->health_bitmap_inject_mask));
1136 }
1137 
1138 static DEVICE_ATTR_ADMIN_RO(health_bitmap_inject);
1139 
1140 static ssize_t perf_stats_show(struct device *dev,
1141 			       struct device_attribute *attr, char *buf)
1142 {
1143 	int index;
1144 	ssize_t rc;
1145 	struct seq_buf s;
1146 	struct papr_scm_perf_stat *stat;
1147 	struct papr_scm_perf_stats *stats;
1148 	struct nvdimm *dimm = to_nvdimm(dev);
1149 	struct papr_scm_priv *p = nvdimm_provider_data(dimm);
1150 
1151 	if (!p->stat_buffer_len)
1152 		return -ENOENT;
1153 
1154 	/* Allocate the buffer for phyp where stats are written */
1155 	stats = kzalloc(p->stat_buffer_len, GFP_KERNEL);
1156 	if (!stats)
1157 		return -ENOMEM;
1158 
1159 	/* Ask phyp to return all dimm perf stats */
1160 	rc = drc_pmem_query_stats(p, stats, 0);
1161 	if (rc)
1162 		goto free_stats;
1163 	/*
1164 	 * Go through the returned output buffer and print stats and
1165 	 * values. Since stat_id is essentially a char string of
1166 	 * 8 bytes, simply use the string format specifier to print it.
1167 	 */
1168 	seq_buf_init(&s, buf, PAGE_SIZE);
1169 	for (index = 0, stat = stats->scm_statistic;
1170 	     index < be32_to_cpu(stats->num_statistics);
1171 	     ++index, ++stat) {
1172 		seq_buf_printf(&s, "%.8s = 0x%016llX\n",
1173 			       stat->stat_id,
1174 			       be64_to_cpu(stat->stat_val));
1175 	}
1176 
1177 free_stats:
1178 	kfree(stats);
1179 	return rc ? rc : (ssize_t)seq_buf_used(&s);
1180 }
1181 static DEVICE_ATTR_ADMIN_RO(perf_stats);
1182 
1183 static ssize_t flags_show(struct device *dev,
1184 			  struct device_attribute *attr, char *buf)
1185 {
1186 	struct nvdimm *dimm = to_nvdimm(dev);
1187 	struct papr_scm_priv *p = nvdimm_provider_data(dimm);
1188 	struct seq_buf s;
1189 	u64 health;
1190 	int rc;
1191 
1192 	rc = drc_pmem_query_health(p);
1193 	if (rc)
1194 		return rc;
1195 
1196 	/* Copy health_bitmap locally, check masks & update out buffer */
1197 	health = READ_ONCE(p->health_bitmap);
1198 
1199 	seq_buf_init(&s, buf, PAGE_SIZE);
1200 	if (health & PAPR_PMEM_UNARMED_MASK)
1201 		seq_buf_printf(&s, "not_armed ");
1202 
1203 	if (health & PAPR_PMEM_BAD_SHUTDOWN_MASK)
1204 		seq_buf_printf(&s, "flush_fail ");
1205 
1206 	if (health & PAPR_PMEM_BAD_RESTORE_MASK)
1207 		seq_buf_printf(&s, "restore_fail ");
1208 
1209 	if (health & PAPR_PMEM_ENCRYPTED)
1210 		seq_buf_printf(&s, "encrypted ");
1211 
1212 	if (health & PAPR_PMEM_SMART_EVENT_MASK)
1213 		seq_buf_printf(&s, "smart_notify ");
1214 
1215 	if (health & PAPR_PMEM_SCRUBBED_AND_LOCKED)
1216 		seq_buf_printf(&s, "scrubbed locked ");
1217 
1218 	if (seq_buf_used(&s))
1219 		seq_buf_printf(&s, "\n");
1220 
1221 	return seq_buf_used(&s);
1222 }
1223 DEVICE_ATTR_RO(flags);
1224 
1225 static ssize_t dirty_shutdown_show(struct device *dev,
1226 			  struct device_attribute *attr, char *buf)
1227 {
1228 	struct nvdimm *dimm = to_nvdimm(dev);
1229 	struct papr_scm_priv *p = nvdimm_provider_data(dimm);
1230 
1231 	return sysfs_emit(buf, "%llu\n", p->dirty_shutdown_counter);
1232 }
1233 DEVICE_ATTR_RO(dirty_shutdown);
1234 
1235 static umode_t papr_nd_attribute_visible(struct kobject *kobj,
1236 					 struct attribute *attr, int n)
1237 {
1238 	struct device *dev = kobj_to_dev(kobj);
1239 	struct nvdimm *nvdimm = to_nvdimm(dev);
1240 	struct papr_scm_priv *p = nvdimm_provider_data(nvdimm);
1241 
1242 	/* For if perf-stats not available remove perf_stats sysfs */
1243 	if (attr == &dev_attr_perf_stats.attr && p->stat_buffer_len == 0)
1244 		return 0;
1245 
1246 	return attr->mode;
1247 }
1248 
1249 /* papr_scm specific dimm attributes */
1250 static struct attribute *papr_nd_attributes[] = {
1251 	&dev_attr_flags.attr,
1252 	&dev_attr_perf_stats.attr,
1253 	&dev_attr_dirty_shutdown.attr,
1254 	&dev_attr_health_bitmap_inject.attr,
1255 	NULL,
1256 };
1257 
1258 static const struct attribute_group papr_nd_attribute_group = {
1259 	.name = "papr",
1260 	.is_visible = papr_nd_attribute_visible,
1261 	.attrs = papr_nd_attributes,
1262 };
1263 
1264 static const struct attribute_group *papr_nd_attr_groups[] = {
1265 	&papr_nd_attribute_group,
1266 	NULL,
1267 };
1268 
1269 static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
1270 {
1271 	struct device *dev = &p->pdev->dev;
1272 	struct nd_mapping_desc mapping;
1273 	struct nd_region_desc ndr_desc;
1274 	unsigned long dimm_flags;
1275 	int target_nid, online_nid;
1276 
1277 	p->bus_desc.ndctl = papr_scm_ndctl;
1278 	p->bus_desc.module = THIS_MODULE;
1279 	p->bus_desc.of_node = p->pdev->dev.of_node;
1280 	p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL);
1281 
1282 	/* Set the dimm command family mask to accept PDSMs */
1283 	set_bit(NVDIMM_FAMILY_PAPR, &p->bus_desc.dimm_family_mask);
1284 
1285 	if (!p->bus_desc.provider_name)
1286 		return -ENOMEM;
1287 
1288 	p->bus = nvdimm_bus_register(NULL, &p->bus_desc);
1289 	if (!p->bus) {
1290 		dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
1291 		kfree(p->bus_desc.provider_name);
1292 		return -ENXIO;
1293 	}
1294 
1295 	dimm_flags = 0;
1296 	set_bit(NDD_LABELING, &dimm_flags);
1297 
1298 	/*
1299 	 * Check if the nvdimm is unarmed. No locking needed as we are still
1300 	 * initializing. Ignore error encountered if any.
1301 	 */
1302 	__drc_pmem_query_health(p);
1303 
1304 	if (p->health_bitmap & PAPR_PMEM_UNARMED_MASK)
1305 		set_bit(NDD_UNARMED, &dimm_flags);
1306 
1307 	p->nvdimm = nvdimm_create(p->bus, p, papr_nd_attr_groups,
1308 				  dimm_flags, PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
1309 	if (!p->nvdimm) {
1310 		dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
1311 		goto err;
1312 	}
1313 
1314 	if (nvdimm_bus_check_dimm_count(p->bus, 1))
1315 		goto err;
1316 
1317 	/* now add the region */
1318 
1319 	memset(&mapping, 0, sizeof(mapping));
1320 	mapping.nvdimm = p->nvdimm;
1321 	mapping.start = 0;
1322 	mapping.size = p->blocks * p->block_size; // XXX: potential overflow?
1323 
1324 	memset(&ndr_desc, 0, sizeof(ndr_desc));
1325 	target_nid = dev_to_node(&p->pdev->dev);
1326 	online_nid = numa_map_to_online_node(target_nid);
1327 	ndr_desc.numa_node = online_nid;
1328 	ndr_desc.target_node = target_nid;
1329 	ndr_desc.res = &p->res;
1330 	ndr_desc.of_node = p->dn;
1331 	ndr_desc.provider_data = p;
1332 	ndr_desc.mapping = &mapping;
1333 	ndr_desc.num_mappings = 1;
1334 	ndr_desc.nd_set = &p->nd_set;
1335 
1336 	if (p->hcall_flush_required) {
1337 		set_bit(ND_REGION_ASYNC, &ndr_desc.flags);
1338 		ndr_desc.flush = papr_scm_pmem_flush;
1339 	}
1340 
1341 	if (p->is_volatile)
1342 		p->region = nvdimm_volatile_region_create(p->bus, &ndr_desc);
1343 	else {
1344 		set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags);
1345 		p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
1346 	}
1347 	if (!p->region) {
1348 		dev_err(dev, "Error registering region %pR from %pOF\n",
1349 				ndr_desc.res, p->dn);
1350 		goto err;
1351 	}
1352 	if (target_nid != online_nid)
1353 		dev_info(dev, "Region registered with target node %d and online node %d",
1354 			 target_nid, online_nid);
1355 
1356 	mutex_lock(&papr_ndr_lock);
1357 	list_add_tail(&p->region_list, &papr_nd_regions);
1358 	mutex_unlock(&papr_ndr_lock);
1359 
1360 	return 0;
1361 
1362 err:	nvdimm_bus_unregister(p->bus);
1363 	kfree(p->bus_desc.provider_name);
1364 	return -ENXIO;
1365 }
1366 
1367 static void papr_scm_add_badblock(struct nd_region *region,
1368 				  struct nvdimm_bus *bus, u64 phys_addr)
1369 {
1370 	u64 aligned_addr = ALIGN_DOWN(phys_addr, L1_CACHE_BYTES);
1371 
1372 	if (nvdimm_bus_add_badrange(bus, aligned_addr, L1_CACHE_BYTES)) {
1373 		pr_err("Bad block registration for 0x%llx failed\n", phys_addr);
1374 		return;
1375 	}
1376 
1377 	pr_debug("Add memory range (0x%llx - 0x%llx) as bad range\n",
1378 		 aligned_addr, aligned_addr + L1_CACHE_BYTES);
1379 
1380 	nvdimm_region_notify(region, NVDIMM_REVALIDATE_POISON);
1381 }
1382 
1383 static int handle_mce_ue(struct notifier_block *nb, unsigned long val,
1384 			 void *data)
1385 {
1386 	struct machine_check_event *evt = data;
1387 	struct papr_scm_priv *p;
1388 	u64 phys_addr;
1389 	bool found = false;
1390 
1391 	if (evt->error_type != MCE_ERROR_TYPE_UE)
1392 		return NOTIFY_DONE;
1393 
1394 	if (list_empty(&papr_nd_regions))
1395 		return NOTIFY_DONE;
1396 
1397 	/*
1398 	 * The physical address obtained here is PAGE_SIZE aligned, so get the
1399 	 * exact address from the effective address
1400 	 */
1401 	phys_addr = evt->u.ue_error.physical_address +
1402 			(evt->u.ue_error.effective_address & ~PAGE_MASK);
1403 
1404 	if (!evt->u.ue_error.physical_address_provided ||
1405 	    !is_zone_device_page(pfn_to_page(phys_addr >> PAGE_SHIFT)))
1406 		return NOTIFY_DONE;
1407 
1408 	/* mce notifier is called from a process context, so mutex is safe */
1409 	mutex_lock(&papr_ndr_lock);
1410 	list_for_each_entry(p, &papr_nd_regions, region_list) {
1411 		if (phys_addr >= p->res.start && phys_addr <= p->res.end) {
1412 			found = true;
1413 			break;
1414 		}
1415 	}
1416 
1417 	if (found)
1418 		papr_scm_add_badblock(p->region, p->bus, phys_addr);
1419 
1420 	mutex_unlock(&papr_ndr_lock);
1421 
1422 	return found ? NOTIFY_OK : NOTIFY_DONE;
1423 }
1424 
1425 static struct notifier_block mce_ue_nb = {
1426 	.notifier_call = handle_mce_ue
1427 };
1428 
1429 static int papr_scm_probe(struct platform_device *pdev)
1430 {
1431 	struct device_node *dn = pdev->dev.of_node;
1432 	u32 drc_index, metadata_size;
1433 	u64 blocks, block_size;
1434 	struct papr_scm_priv *p;
1435 	u8 uuid_raw[UUID_SIZE];
1436 	const char *uuid_str;
1437 	ssize_t stat_size;
1438 	uuid_t uuid;
1439 	int rc;
1440 
1441 	/* check we have all the required DT properties */
1442 	if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) {
1443 		dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
1444 		return -ENODEV;
1445 	}
1446 
1447 	if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
1448 		dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
1449 		return -ENODEV;
1450 	}
1451 
1452 	if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
1453 		dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
1454 		return -ENODEV;
1455 	}
1456 
1457 	if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
1458 		dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
1459 		return -ENODEV;
1460 	}
1461 
1462 
1463 	p = kzalloc(sizeof(*p), GFP_KERNEL);
1464 	if (!p)
1465 		return -ENOMEM;
1466 
1467 	/* Initialize the dimm mutex */
1468 	mutex_init(&p->health_mutex);
1469 
1470 	/* optional DT properties */
1471 	of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);
1472 
1473 	p->dn = dn;
1474 	p->drc_index = drc_index;
1475 	p->block_size = block_size;
1476 	p->blocks = blocks;
1477 	p->is_volatile = !of_property_read_bool(dn, "ibm,cache-flush-required");
1478 	p->hcall_flush_required = of_property_read_bool(dn, "ibm,hcall-flush-required");
1479 
1480 	if (of_property_read_u64(dn, "ibm,persistence-failed-count",
1481 				 &p->dirty_shutdown_counter))
1482 		p->dirty_shutdown_counter = 0;
1483 
1484 	/* We just need to ensure that set cookies are unique across */
1485 	uuid_parse(uuid_str, &uuid);
1486 
1487 	/*
1488 	 * The cookie1 and cookie2 are not really little endian.
1489 	 * We store a raw buffer representation of the
1490 	 * uuid string so that we can compare this with the label
1491 	 * area cookie irrespective of the endian configuration
1492 	 * with which the kernel is built.
1493 	 *
1494 	 * Historically we stored the cookie in the below format.
1495 	 * for a uuid string 72511b67-0b3b-42fd-8d1d-5be3cae8bcaa
1496 	 *	cookie1 was 0xfd423b0b671b5172
1497 	 *	cookie2 was 0xaabce8cae35b1d8d
1498 	 */
1499 	export_uuid(uuid_raw, &uuid);
1500 	p->nd_set.cookie1 = get_unaligned_le64(&uuid_raw[0]);
1501 	p->nd_set.cookie2 = get_unaligned_le64(&uuid_raw[8]);
1502 
1503 	/* might be zero */
1504 	p->metadata_size = metadata_size;
1505 	p->pdev = pdev;
1506 
1507 	/* request the hypervisor to bind this region to somewhere in memory */
1508 	rc = drc_pmem_bind(p);
1509 
1510 	/* If phyp says drc memory still bound then force unbound and retry */
1511 	if (rc == H_OVERLAP)
1512 		rc = drc_pmem_query_n_bind(p);
1513 
1514 	if (rc != H_SUCCESS) {
1515 		dev_err(&p->pdev->dev, "bind err: %d\n", rc);
1516 		rc = -ENXIO;
1517 		goto err;
1518 	}
1519 
1520 	/* setup the resource for the newly bound range */
1521 	p->res.start = p->bound_addr;
1522 	p->res.end   = p->bound_addr + p->blocks * p->block_size - 1;
1523 	p->res.name  = pdev->name;
1524 	p->res.flags = IORESOURCE_MEM;
1525 
1526 	/* Try retrieving the stat buffer and see if its supported */
1527 	stat_size = drc_pmem_query_stats(p, NULL, 0);
1528 	if (stat_size > 0) {
1529 		p->stat_buffer_len = stat_size;
1530 		dev_dbg(&p->pdev->dev, "Max perf-stat size %lu-bytes\n",
1531 			p->stat_buffer_len);
1532 	}
1533 
1534 	rc = papr_scm_nvdimm_init(p);
1535 	if (rc)
1536 		goto err2;
1537 
1538 	platform_set_drvdata(pdev, p);
1539 	papr_scm_pmu_register(p);
1540 
1541 	return 0;
1542 
1543 err2:	drc_pmem_unbind(p);
1544 err:	kfree(p);
1545 	return rc;
1546 }
1547 
1548 static int papr_scm_remove(struct platform_device *pdev)
1549 {
1550 	struct papr_scm_priv *p = platform_get_drvdata(pdev);
1551 
1552 	mutex_lock(&papr_ndr_lock);
1553 	list_del(&p->region_list);
1554 	mutex_unlock(&papr_ndr_lock);
1555 
1556 	nvdimm_bus_unregister(p->bus);
1557 	drc_pmem_unbind(p);
1558 
1559 	if (pdev->archdata.priv)
1560 		unregister_nvdimm_pmu(pdev->archdata.priv);
1561 
1562 	pdev->archdata.priv = NULL;
1563 	kfree(p->nvdimm_events_map);
1564 	kfree(p->bus_desc.provider_name);
1565 	kfree(p);
1566 
1567 	return 0;
1568 }
1569 
1570 static const struct of_device_id papr_scm_match[] = {
1571 	{ .compatible = "ibm,pmemory" },
1572 	{ .compatible = "ibm,pmemory-v2" },
1573 	{ },
1574 };
1575 
1576 static struct platform_driver papr_scm_driver = {
1577 	.probe = papr_scm_probe,
1578 	.remove = papr_scm_remove,
1579 	.driver = {
1580 		.name = "papr_scm",
1581 		.of_match_table = papr_scm_match,
1582 	},
1583 };
1584 
1585 static int __init papr_scm_init(void)
1586 {
1587 	int ret;
1588 
1589 	ret = platform_driver_register(&papr_scm_driver);
1590 	if (!ret)
1591 		mce_register_notifier(&mce_ue_nb);
1592 
1593 	return ret;
1594 }
1595 module_init(papr_scm_init);
1596 
1597 static void __exit papr_scm_exit(void)
1598 {
1599 	mce_unregister_notifier(&mce_ue_nb);
1600 	platform_driver_unregister(&papr_scm_driver);
1601 }
1602 module_exit(papr_scm_exit);
1603 
1604 MODULE_DEVICE_TABLE(of, papr_scm_match);
1605 MODULE_LICENSE("GPL");
1606 MODULE_AUTHOR("IBM Corporation");
1607