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
129	static int papr_scm_pmem_flush(struct nd_region *nd_region,
130	struct bio *bio __maybe_unused)
131	{
132	struct papr_scm_priv *p = nd_region_provider_data(nd_region);
133	unsigned long ret_buf[PLPAR_HCALL_BUFSIZE], token = 0;
134	long rc;
135
136	dev_dbg(&p->pdev->dev, "flush drc 0x%x", p->drc_index);
137
138	do {
139	rc = plpar_hcall(H_SCM_FLUSH, ret_buf, p->drc_index, token);
140	token = ret_buf[0];
141
142	/* Check if we are stalled for some time */
143	if (H_IS_LONG_BUSY(rc)) {
144	msleep(get_longbusy_msecs(rc));
145	rc = H_BUSY;
146	} else if (rc == H_BUSY) {
147	cond_resched();
148	}
149	} while (rc == H_BUSY);
150
151	if (rc) {
152	dev_err(&p->pdev->dev, "flush error: %ld", rc);
153	rc = -EIO;
154	} else {
155	dev_dbg(&p->pdev->dev, "flush drc 0x%x complete", p->drc_index);
156	}
157
158	return rc;
159	}
160
161	static LIST_HEAD(papr_nd_regions);
162	static DEFINE_MUTEX(papr_ndr_lock);
163
164	static int drc_pmem_bind(struct papr_scm_priv *p)
165	{
166	unsigned long ret[PLPAR_HCALL_BUFSIZE];
167	uint64_t saved = 0;
168	uint64_t token;
169	int64_t rc;
170
171	/*
172	* When the hypervisor cannot map all the requested memory in a single
173	* hcall it returns H_BUSY and we call again with the token until
174	* we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
175	* leave the system in an undefined state, so we wait.
176	*/
177	token = 0;
178
179	do {
180	rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
181	p->blocks, BIND_ANY_ADDR, token);
182	token = ret[0];
183	if (!saved)
184	saved = ret[1];
185	cond_resched();
186	} while (rc == H_BUSY);
187
188	if (rc)
189	return rc;
190
191	p->bound_addr = saved;
192	dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n",
193	p->drc_index, (unsigned long)saved);
194	return rc;
195	}
196
197	static void drc_pmem_unbind(struct papr_scm_priv *p)
198	{
199	unsigned long ret[PLPAR_HCALL_BUFSIZE];
200	uint64_t token = 0;
201	int64_t rc;
202
203	dev_dbg(&p->pdev->dev, "unbind drc 0x%x\n", p->drc_index);
204
205	/* NB: unbind has the same retry requirements as drc_pmem_bind() */
206	do {
207
208	/* Unbind of all SCM resources associated with drcIndex */
209	rc = plpar_hcall(H_SCM_UNBIND_ALL, ret, H_UNBIND_SCOPE_DRC,
210	p->drc_index, token);
211	token = ret[0];
212
213	/* Check if we are stalled for some time */
214	if (H_IS_LONG_BUSY(rc)) {
215	msleep(get_longbusy_msecs(rc));
216	rc = H_BUSY;
217	} else if (rc == H_BUSY) {
218	cond_resched();
219	}
220
221	} while (rc == H_BUSY);
222
223	if (rc)
224	dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);
225	else
226	dev_dbg(&p->pdev->dev, "unbind drc 0x%x complete\n",
227	p->drc_index);
228
229	return;
230	}
231
232	static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
233	{
234	unsigned long start_addr;
235	unsigned long end_addr;
236	unsigned long ret[PLPAR_HCALL_BUFSIZE];
237	int64_t rc;
238
239
240	rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
241	p->drc_index, 0);
242	if (rc)
243	goto err_out;
244	start_addr = ret[0];
245
246	/* Make sure the full region is bound. */
247	rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
248	p->drc_index, p->blocks - 1);
249	if (rc)
250	goto err_out;
251	end_addr = ret[0];
252
253	if ((end_addr - start_addr) != ((p->blocks - 1) * p->block_size))
254	goto err_out;
255
256	p->bound_addr = start_addr;
257	dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n", p->drc_index, start_addr);
258	return rc;
259
260	err_out:
261	dev_info(&p->pdev->dev,
262	"Failed to query, trying an unbind followed by bind");
263	drc_pmem_unbind(p);
264	return drc_pmem_bind(p);
265	}
266
267	/*
268	* Query the Dimm performance stats from PHYP and copy them (if returned) to
269	* provided struct papr_scm_perf_stats instance 'stats' that can hold atleast
270	* (num_stats + header) bytes.
271	* - If buff_stats == NULL the return value is the size in bytes of the buffer
272	* needed to hold all supported performance-statistics.
273	* - If buff_stats != NULL and num_stats == 0 then we copy all known
274	* performance-statistics to 'buff_stat' and expect to be large enough to
275	* hold them.
276	* - if buff_stats != NULL and num_stats > 0 then copy the requested
277	* performance-statistics to buff_stats.
278	*/
279	static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p,
280	struct papr_scm_perf_stats *buff_stats,
281	unsigned int num_stats)
282	{
283	unsigned long ret[PLPAR_HCALL_BUFSIZE];
284	size_t size;
285	s64 rc;
286
287	/* Setup the out buffer */
288	if (buff_stats) {
289	memcpy(buff_stats->eye_catcher,
290	PAPR_SCM_PERF_STATS_EYECATCHER, 8);
291	buff_stats->stats_version =
292	cpu_to_be32(PAPR_SCM_PERF_STATS_VERSION);
293	buff_stats->num_statistics =
294	cpu_to_be32(num_stats);
295
296	/*
297	* Calculate the buffer size based on num-stats provided
298	* or use the prefetched max buffer length
299	*/
300	if (num_stats)
301	/* Calculate size from the num_stats */
302	size = sizeof(struct papr_scm_perf_stats) +
303	num_stats * sizeof(struct papr_scm_perf_stat);
304	else
305	size = p->stat_buffer_len;
306	} else {
307	/* In case of no out buffer ignore the size */
308	size = 0;
309	}
310
311	/* Do the HCALL asking PHYP for info */
312	rc = plpar_hcall(H_SCM_PERFORMANCE_STATS, ret, p->drc_index,
313	buff_stats ? virt_to_phys(buff_stats) : 0,
314	size);
315
316	/* Check if the error was due to an unknown stat-id */
317	if (rc == H_PARTIAL) {
318	dev_err(&p->pdev->dev,
319	"Unknown performance stats, Err:0x%016lX\n", ret[0]);
320	return -ENOENT;
321	} else if (rc == H_AUTHORITY) {
322	dev_info(&p->pdev->dev,
323	"Permission denied while accessing performance stats");
324	return -EPERM;
325	} else if (rc == H_UNSUPPORTED) {
326	dev_dbg(&p->pdev->dev, "Performance stats unsupported\n");
327	return -EOPNOTSUPP;
328	} else if (rc != H_SUCCESS) {
329	dev_err(&p->pdev->dev,
330	"Failed to query performance stats, Err:%lld\n", rc);
331	return -EIO;
332
333	} else if (!size) {
334	/* Handle case where stat buffer size was requested */
335	dev_dbg(&p->pdev->dev,
336	"Performance stats size %ld\n", ret[0]);
337	return ret[0];
338	}
339
340	/* Successfully fetched the requested stats from phyp */
341	dev_dbg(&p->pdev->dev,
342	"Performance stats returned %d stats\n",
343	be32_to_cpu(buff_stats->num_statistics));
344	return 0;
345	}
346
347	#ifdef CONFIG_PERF_EVENTS
348	#define to_nvdimm_pmu(_pmu) container_of(_pmu, struct nvdimm_pmu, pmu)
349
350	static const char * const nvdimm_events_map[] = {
351	[1] = "CtlResCt",
352	[2] = "CtlResTm",
353	[3] = "PonSecs ",
354	[4] = "MemLife ",
355	[5] = "CritRscU",
356	[6] = "HostLCnt",
357	[7] = "HostSCnt",
358	[8] = "HostSDur",
359	[9] = "HostLDur",
360	[10] = "MedRCnt ",
361	[11] = "MedWCnt ",
362	[12] = "MedRDur ",
363	[13] = "MedWDur ",
364	[14] = "CchRHCnt",
365	[15] = "CchWHCnt",
366	[16] = "FastWCnt",
367	};
368
369	static int papr_scm_pmu_get_value(struct perf_event *event, struct device *dev, u64 *count)
370	{
371	struct papr_scm_perf_stat *stat;
372	struct papr_scm_perf_stats *stats;
373	struct papr_scm_priv *p = dev_get_drvdata(dev);
374	int rc, size;
375
376	/* Invalid eventcode */
377	if (event->attr.config == 0 || event->attr.config >= ARRAY_SIZE(nvdimm_events_map))
378	return -EINVAL;
379
380	/* Allocate request buffer enough to hold single performance stat */
381	size = sizeof(struct papr_scm_perf_stats) +
382	sizeof(struct papr_scm_perf_stat);
383
384	if (!p)
385	return -EINVAL;
386
387	stats = kzalloc(size, GFP_KERNEL);
388	if (!stats)
389	return -ENOMEM;
390
391	stat = &stats->scm_statistic[0];
392	memcpy(&stat->stat_id,
393	nvdimm_events_map[event->attr.config],
394	sizeof(stat->stat_id));
395	stat->stat_val = 0;
396
397	rc = drc_pmem_query_stats(p, buff_stats: stats, num_stats: 1);
398	if (rc < 0) {
399	kfree(objp: stats);
400	return rc;
401	}
402
403	*count = be64_to_cpu(stat->stat_val);
404	kfree(objp: stats);
405	return 0;
406	}
407
408	static int papr_scm_pmu_event_init(struct perf_event *event)
409	{
410	struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
411	struct papr_scm_priv *p;
412
413	if (!nd_pmu)
414	return -EINVAL;
415
416	/* test the event attr type for PMU enumeration */
417	if (event->attr.type != event->pmu->type)
418	return -ENOENT;
419
420	/* it does not support event sampling mode */
421	if (is_sampling_event(event))
422	return -EOPNOTSUPP;
423
424	/* no branch sampling */
425	if (has_branch_stack(event))
426	return -EOPNOTSUPP;
427
428	p = (struct papr_scm_priv *)nd_pmu->dev->driver_data;
429	if (!p)
430	return -EINVAL;
431
432	/* Invalid eventcode */
433	if (event->attr.config == 0 || event->attr.config > 16)
434	return -EINVAL;
435
436	return 0;
437	}
438
439	static int papr_scm_pmu_add(struct perf_event *event, int flags)
440	{
441	u64 count;
442	int rc;
443	struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
444
445	if (!nd_pmu)
446	return -EINVAL;
447
448	if (flags & PERF_EF_START) {
449	rc = papr_scm_pmu_get_value(event, dev: nd_pmu->dev, count: &count);
450	if (rc)
451	return rc;
452
453	local64_set(&event->hw.prev_count, count);
454	}
455
456	return 0;
457	}
458
459	static void papr_scm_pmu_read(struct perf_event *event)
460	{
461	u64 prev, now;
462	int rc;
463	struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
464
465	if (!nd_pmu)
466	return;
467
468	rc = papr_scm_pmu_get_value(event, dev: nd_pmu->dev, count: &now);
469	if (rc)
470	return;
471
472	prev = local64_xchg(&event->hw.prev_count, now);
473	local64_add(now - prev, &event->count);
474	}
475
476	static void papr_scm_pmu_del(struct perf_event *event, int flags)
477	{
478	papr_scm_pmu_read(event);
479	}
480
481	static void papr_scm_pmu_register(struct papr_scm_priv *p)
482	{
483	struct nvdimm_pmu *nd_pmu;
484	int rc, nodeid;
485
486	nd_pmu = kzalloc(size: sizeof(*nd_pmu), GFP_KERNEL);
487	if (!nd_pmu) {
488	rc = -ENOMEM;
489	goto pmu_err_print;
490	}
491
492	if (!p->stat_buffer_len) {
493	rc = -ENOENT;
494	goto pmu_check_events_err;
495	}
496
497	nd_pmu->pmu.task_ctx_nr = perf_invalid_context;
498	nd_pmu->pmu.name = nvdimm_name(nvdimm: p->nvdimm);
499	nd_pmu->pmu.event_init = papr_scm_pmu_event_init;
500	nd_pmu->pmu.read = papr_scm_pmu_read;
501	nd_pmu->pmu.add = papr_scm_pmu_add;
502	nd_pmu->pmu.del = papr_scm_pmu_del;
503
504	nd_pmu->pmu.capabilities = PERF_PMU_CAP_NO_INTERRUPT |
505	PERF_PMU_CAP_NO_EXCLUDE;
506
507	/*updating the cpumask variable */
508	nodeid = numa_map_to_online_node(dev_to_node(&p->pdev->dev));
509	nd_pmu->arch_cpumask = *cpumask_of_node(node: nodeid);
510
511	rc = register_nvdimm_pmu(nvdimm: nd_pmu, pdev: p->pdev);
512	if (rc)
513	goto pmu_check_events_err;
514
515	/*
516	* Set archdata.priv value to nvdimm_pmu structure, to handle the
517	* unregistering of pmu device.
518	*/
519	p->pdev->archdata.priv = nd_pmu;
520	return;
521
522	pmu_check_events_err:
523	kfree(objp: nd_pmu);
524	pmu_err_print:
525	dev_info(&p->pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
526	}
527
528	#else
529	static void papr_scm_pmu_register(struct papr_scm_priv *p) { }
530	#endif
531
532	/*
533	* Issue hcall to retrieve dimm health info and populate papr_scm_priv with the
534	* health information.
535	*/
536	static int __drc_pmem_query_health(struct papr_scm_priv *p)
537	{
538	unsigned long ret[PLPAR_HCALL_BUFSIZE];
539	u64 bitmap = 0;
540	long rc;
541
542	/* issue the hcall */
543	rc = plpar_hcall(H_SCM_HEALTH, ret, p->drc_index);
544	if (rc == H_SUCCESS)
545	bitmap = ret[0] & ret[1];
546	else if (rc == H_FUNCTION)
547	dev_info_once(&p->pdev->dev,
548	"Hcall H_SCM_HEALTH not implemented, assuming empty health bitmap");
549	else {
550
551	dev_err(&p->pdev->dev,
552	"Failed to query health information, Err:%ld\n", rc);
553	return -ENXIO;
554	}
555
556	p->lasthealth_jiffies = jiffies;
557	/* Allow injecting specific health bits via inject mask. */
558	if (p->health_bitmap_inject_mask)
559	bitmap = (bitmap & ~p->health_bitmap_inject_mask) |
560	p->health_bitmap_inject_mask;
561	WRITE_ONCE(p->health_bitmap, bitmap);
562	dev_dbg(&p->pdev->dev,
563	"Queried dimm health info. Bitmap:0x%016lx Mask:0x%016lx\n",
564	ret[0], ret[1]);
565
566	return 0;
567	}
568
569	/* Min interval in seconds for assuming stable dimm health */
570	#define MIN_HEALTH_QUERY_INTERVAL 60
571
572	/* Query cached health info and if needed call drc_pmem_query_health */
573	static int drc_pmem_query_health(struct papr_scm_priv *p)
574	{
575	unsigned long cache_timeout;
576	int rc;
577
578	/* Protect concurrent modifications to papr_scm_priv */
579	rc = mutex_lock_interruptible(&p->health_mutex);
580	if (rc)
581	return rc;
582
583	/* Jiffies offset for which the health data is assumed to be same */
584	cache_timeout = p->lasthealth_jiffies +
585	msecs_to_jiffies(MIN_HEALTH_QUERY_INTERVAL * 1000);
586
587	/* Fetch new health info is its older than MIN_HEALTH_QUERY_INTERVAL */
588	if (time_after(jiffies, cache_timeout))
589	rc = __drc_pmem_query_health(p);
590	else
591	/* Assume cached health data is valid */
592	rc = 0;
593
594	mutex_unlock(lock: &p->health_mutex);
595	return rc;
596	}
597
598	static int papr_scm_meta_get(struct papr_scm_priv *p,
599	struct nd_cmd_get_config_data_hdr *hdr)
600	{
601	unsigned long data[PLPAR_HCALL_BUFSIZE];
602	unsigned long offset, data_offset;
603	int len, read;
604	int64_t ret;
605
606	if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
607	return -EINVAL;
608
609	for (len = hdr->in_length; len; len -= read) {
610
611	data_offset = hdr->in_length - len;
612	offset = hdr->in_offset + data_offset;
613
614	if (len >= 8)
615	read = 8;
616	else if (len >= 4)
617	read = 4;
618	else if (len >= 2)
619	read = 2;
620	else
621	read = 1;
622
623	ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
624	offset, read);
625
626	if (ret == H_PARAMETER) /* bad DRC index */
627	return -ENODEV;
628	if (ret)
629	return -EINVAL; /* other invalid parameter */
630
631	switch (read) {
632	case 8:
633	*(uint64_t *)(hdr->out_buf + data_offset) = be64_to_cpu(data[0]);
634	break;
635	case 4:
636	*(uint32_t *)(hdr->out_buf + data_offset) = be32_to_cpu(data[0] & 0xffffffff);
637	break;
638
639	case 2:
640	*(uint16_t *)(hdr->out_buf + data_offset) = be16_to_cpu(data[0] & 0xffff);
641	break;
642
643	case 1:
644	*(uint8_t *)(hdr->out_buf + data_offset) = (data[0] & 0xff);
645	break;
646	}
647	}
648	return 0;
649	}
650
651	static int papr_scm_meta_set(struct papr_scm_priv *p,
652	struct nd_cmd_set_config_hdr *hdr)
653	{
654	unsigned long offset, data_offset;
655	int len, wrote;
656	unsigned long data;
657	__be64 data_be;
658	int64_t ret;
659
660	if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
661	return -EINVAL;
662
663	for (len = hdr->in_length; len; len -= wrote) {
664
665	data_offset = hdr->in_length - len;
666	offset = hdr->in_offset + data_offset;
667
668	if (len >= 8) {
669	data = *(uint64_t *)(hdr->in_buf + data_offset);
670	data_be = cpu_to_be64(data);
671	wrote = 8;
672	} else if (len >= 4) {
673	data = *(uint32_t *)(hdr->in_buf + data_offset);
674	data &= 0xffffffff;
675	data_be = cpu_to_be32(data);
676	wrote = 4;
677	} else if (len >= 2) {
678	data = *(uint16_t *)(hdr->in_buf + data_offset);
679	data &= 0xffff;
680	data_be = cpu_to_be16(data);
681	wrote = 2;
682	} else {
683	data_be = *(uint8_t *)(hdr->in_buf + data_offset);
684	data_be &= 0xff;
685	wrote = 1;
686	}
687
688	ret = plpar_hcall_norets(H_SCM_WRITE_METADATA, p->drc_index,
689	offset, data_be, wrote);
690	if (ret == H_PARAMETER) /* bad DRC index */
691	return -ENODEV;
692	if (ret)
693	return -EINVAL; /* other invalid parameter */
694	}
695
696	return 0;
697	}
698
699	/*
700	* Do a sanity checks on the inputs args to dimm-control function and return
701	* '0' if valid. Validation of PDSM payloads happens later in
702	* papr_scm_service_pdsm.
703	*/
704	static int is_cmd_valid(struct nvdimm *nvdimm, unsigned int cmd, void *buf,
705	unsigned int buf_len)
706	{
707	unsigned long cmd_mask = PAPR_SCM_DIMM_CMD_MASK;
708	struct nd_cmd_pkg *nd_cmd;
709	struct papr_scm_priv *p;
710	enum papr_pdsm pdsm;
711
712	/* Only dimm-specific calls are supported atm */
713	if (!nvdimm)
714	return -EINVAL;
715
716	/* get the provider data from struct nvdimm */
717	p = nvdimm_provider_data(nvdimm);
718
719	if (!test_bit(cmd, &cmd_mask)) {
720	dev_dbg(&p->pdev->dev, "Unsupported cmd=%u\n", cmd);
721	return -EINVAL;
722	}
723
724	/* For CMD_CALL verify pdsm request */
725	if (cmd == ND_CMD_CALL) {
726	/* Verify the envelope and envelop size */
727	if (!buf ||
728	buf_len < (sizeof(struct nd_cmd_pkg) + ND_PDSM_HDR_SIZE)) {
729	dev_dbg(&p->pdev->dev, "Invalid pkg size=%u\n",
730	buf_len);
731	return -EINVAL;
732	}
733
734	/* Verify that the nd_cmd_pkg.nd_family is correct */
735	nd_cmd = (struct nd_cmd_pkg *)buf;
736
737	if (nd_cmd->nd_family != NVDIMM_FAMILY_PAPR) {
738	dev_dbg(&p->pdev->dev, "Invalid pkg family=0x%llx\n",
739	nd_cmd->nd_family);
740	return -EINVAL;
741	}
742
743	pdsm = (enum papr_pdsm)nd_cmd->nd_command;
744
745	/* Verify if the pdsm command is valid */
746	if (pdsm <= PAPR_PDSM_MIN || pdsm >= PAPR_PDSM_MAX) {
747	dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid PDSM\n",
748	pdsm);
749	return -EINVAL;
750	}
751
752	/* Have enough space to hold returned 'nd_pkg_pdsm' header */
753	if (nd_cmd->nd_size_out < ND_PDSM_HDR_SIZE) {
754	dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid payload\n",
755	pdsm);
756	return -EINVAL;
757	}
758	}
759
760	/* Let the command be further processed */
761	return 0;
762	}
763
764	static int papr_pdsm_fuel_gauge(struct papr_scm_priv *p,
765	union nd_pdsm_payload *payload)
766	{
767	int rc, size;
768	u64 statval;
769	struct papr_scm_perf_stat *stat;
770	struct papr_scm_perf_stats *stats;
771
772	/* Silently fail if fetching performance metrics isn't supported */
773	if (!p->stat_buffer_len)
774	return 0;
775
776	/* Allocate request buffer enough to hold single performance stat */
777	size = sizeof(struct papr_scm_perf_stats) +
778	sizeof(struct papr_scm_perf_stat);
779
780	stats = kzalloc(size, GFP_KERNEL);
781	if (!stats)
782	return -ENOMEM;
783
784	stat = &stats->scm_statistic[0];
785	memcpy(&stat->stat_id, "MemLife ", sizeof(stat->stat_id));
786	stat->stat_val = 0;
787
788	/* Fetch the fuel gauge and populate it in payload */
789	rc = drc_pmem_query_stats(p, buff_stats: stats, num_stats: 1);
790	if (rc < 0) {
791	dev_dbg(&p->pdev->dev, "Err(%d) fetching fuel gauge\n", rc);
792	goto free_stats;
793	}
794
795	statval = be64_to_cpu(stat->stat_val);
796	dev_dbg(&p->pdev->dev,
797	"Fetched fuel-gauge %llu", statval);
798	payload->health.extension_flags |=
799	PDSM_DIMM_HEALTH_RUN_GAUGE_VALID;
800	payload->health.dimm_fuel_gauge = statval;
801
802	rc = sizeof(struct nd_papr_pdsm_health);
803
804	free_stats:
805	kfree(objp: stats);
806	return rc;
807	}
808
809	/* Add the dirty-shutdown-counter value to the pdsm */
810	static int papr_pdsm_dsc(struct papr_scm_priv *p,
811	union nd_pdsm_payload *payload)
812	{
813	payload->health.extension_flags |= PDSM_DIMM_DSC_VALID;
814	payload->health.dimm_dsc = p->dirty_shutdown_counter;
815
816	return sizeof(struct nd_papr_pdsm_health);
817	}
818
819	/* Fetch the DIMM health info and populate it in provided package. */
820	static int papr_pdsm_health(struct papr_scm_priv *p,
821	union nd_pdsm_payload *payload)
822	{
823	int rc;
824
825	/* Ensure dimm health mutex is taken preventing concurrent access */
826	rc = mutex_lock_interruptible(&p->health_mutex);
827	if (rc)
828	goto out;
829
830	/* Always fetch upto date dimm health data ignoring cached values */
831	rc = __drc_pmem_query_health(p);
832	if (rc) {
833	mutex_unlock(lock: &p->health_mutex);
834	goto out;
835	}
836
837	/* update health struct with various flags derived from health bitmap */
838	payload->health = (struct nd_papr_pdsm_health) {
839	.extension_flags = 0,
840	.dimm_unarmed = !!(p->health_bitmap & PAPR_PMEM_UNARMED_MASK),
841	.dimm_bad_shutdown = !!(p->health_bitmap & PAPR_PMEM_BAD_SHUTDOWN_MASK),
842	.dimm_bad_restore = !!(p->health_bitmap & PAPR_PMEM_BAD_RESTORE_MASK),
843	.dimm_scrubbed = !!(p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED),
844	.dimm_locked = !!(p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED),
845	.dimm_encrypted = !!(p->health_bitmap & PAPR_PMEM_ENCRYPTED),
846	.dimm_health = PAPR_PDSM_DIMM_HEALTHY,
847	};
848
849	/* Update field dimm_health based on health_bitmap flags */
850	if (p->health_bitmap & PAPR_PMEM_HEALTH_FATAL)
851	payload->health.dimm_health = PAPR_PDSM_DIMM_FATAL;
852	else if (p->health_bitmap & PAPR_PMEM_HEALTH_CRITICAL)
853	payload->health.dimm_health = PAPR_PDSM_DIMM_CRITICAL;
854	else if (p->health_bitmap & PAPR_PMEM_HEALTH_UNHEALTHY)
855	payload->health.dimm_health = PAPR_PDSM_DIMM_UNHEALTHY;
856
857	/* struct populated hence can release the mutex now */
858	mutex_unlock(lock: &p->health_mutex);
859
860	/* Populate the fuel gauge meter in the payload */
861	papr_pdsm_fuel_gauge(p, payload);
862	/* Populate the dirty-shutdown-counter field */
863	papr_pdsm_dsc(p, payload);
864
865	rc = sizeof(struct nd_papr_pdsm_health);
866
867	out:
868	return rc;
869	}
870
871	/* Inject a smart error Add the dirty-shutdown-counter value to the pdsm */
872	static int papr_pdsm_smart_inject(struct papr_scm_priv *p,
873	union nd_pdsm_payload *payload)
874	{
875	int rc;
876	u32 supported_flags = 0;
877	u64 inject_mask = 0, clear_mask = 0;
878	u64 mask;
879
880	/* Check for individual smart error flags and update inject/clear masks */
881	if (payload->smart_inject.flags & PDSM_SMART_INJECT_HEALTH_FATAL) {
882	supported_flags |= PDSM_SMART_INJECT_HEALTH_FATAL;
883	if (payload->smart_inject.fatal_enable)
884	inject_mask |= PAPR_PMEM_HEALTH_FATAL;
885	else
886	clear_mask |= PAPR_PMEM_HEALTH_FATAL;
887	}
888
889	if (payload->smart_inject.flags & PDSM_SMART_INJECT_BAD_SHUTDOWN) {
890	supported_flags |= PDSM_SMART_INJECT_BAD_SHUTDOWN;
891	if (payload->smart_inject.unsafe_shutdown_enable)
892	inject_mask |= PAPR_PMEM_SHUTDOWN_DIRTY;
893	else
894	clear_mask |= PAPR_PMEM_SHUTDOWN_DIRTY;
895	}
896
897	dev_dbg(&p->pdev->dev, "[Smart-inject] inject_mask=%#llx clear_mask=%#llx\n",
898	inject_mask, clear_mask);
899
900	/* Prevent concurrent access to dimm health bitmap related members */
901	rc = mutex_lock_interruptible(&p->health_mutex);
902	if (rc)
903	return rc;
904
905	/* Use inject/clear masks to set health_bitmap_inject_mask */
906	mask = READ_ONCE(p->health_bitmap_inject_mask);
907	mask = (mask & ~clear_mask) | inject_mask;
908	WRITE_ONCE(p->health_bitmap_inject_mask, mask);
909
910	/* Invalidate cached health bitmap */
911	p->lasthealth_jiffies = 0;
912
913	mutex_unlock(lock: &p->health_mutex);
914
915	/* Return the supported flags back to userspace */
916	payload->smart_inject.flags = supported_flags;
917
918	return sizeof(struct nd_papr_pdsm_health);
919	}
920
921	/*
922	* 'struct pdsm_cmd_desc'
923	* Identifies supported PDSMs' expected length of in/out payloads
924	* and pdsm service function.
925	*
926	* size_in : Size of input payload if any in the PDSM request.
927	* size_out : Size of output payload if any in the PDSM request.
928	* service : Service function for the PDSM request. Return semantics:
929	* rc < 0 : Error servicing PDSM and rc indicates the error.
930	* rc >=0 : Serviced successfully and 'rc' indicate number of
931	* bytes written to payload.
932	*/
933	struct pdsm_cmd_desc {
934	u32 size_in;
935	u32 size_out;
936	int (*service)(struct papr_scm_priv *dimm,
937	union nd_pdsm_payload *payload);
938	};
939
940	/* Holds all supported PDSMs' command descriptors */
941	static const struct pdsm_cmd_desc __pdsm_cmd_descriptors[] = {
942	[PAPR_PDSM_MIN] = {
943	.size_in = 0,
944	.size_out = 0,
945	.service = NULL,
946	},
947	/* New PDSM command descriptors to be added below */
948
949	[PAPR_PDSM_HEALTH] = {
950	.size_in = 0,
951	.size_out = sizeof(struct nd_papr_pdsm_health),
952	.service = papr_pdsm_health,
953	},
954
955	[PAPR_PDSM_SMART_INJECT] = {
956	.size_in = sizeof(struct nd_papr_pdsm_smart_inject),
957	.size_out = sizeof(struct nd_papr_pdsm_smart_inject),
958	.service = papr_pdsm_smart_inject,
959	},
960	/* Empty */
961	[PAPR_PDSM_MAX] = {
962	.size_in = 0,
963	.size_out = 0,
964	.service = NULL,
965	},
966	};
967
968	/* Given a valid pdsm cmd return its command descriptor else return NULL */
969	static inline const struct pdsm_cmd_desc *pdsm_cmd_desc(enum papr_pdsm cmd)
970	{
971	if (cmd >= 0 || cmd < ARRAY_SIZE(__pdsm_cmd_descriptors))
972	return &__pdsm_cmd_descriptors[cmd];
973
974	return NULL;
975	}
976
977	/*
978	* For a given pdsm request call an appropriate service function.
979	* Returns errors if any while handling the pdsm command package.
980	*/
981	static int papr_scm_service_pdsm(struct papr_scm_priv *p,
982	struct nd_cmd_pkg *pkg)
983	{
984	/* Get the PDSM header and PDSM command */
985	struct nd_pkg_pdsm *pdsm_pkg = (struct nd_pkg_pdsm *)pkg->nd_payload;
986	enum papr_pdsm pdsm = (enum papr_pdsm)pkg->nd_command;
987	const struct pdsm_cmd_desc *pdsc;
988	int rc;
989
990	/* Fetch corresponding pdsm descriptor for validation and servicing */
991	pdsc = pdsm_cmd_desc(cmd: pdsm);
992
993	/* Validate pdsm descriptor */
994	/* Ensure that reserved fields are 0 */
995	if (pdsm_pkg->reserved[0] || pdsm_pkg->reserved[1]) {
996	dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid reserved field\n",
997	pdsm);
998	return -EINVAL;
999	}
1000
1001	/* If pdsm expects some input, then ensure that the size_in matches */
1002	if (pdsc->size_in &&
1003	pkg->nd_size_in != (pdsc->size_in + ND_PDSM_HDR_SIZE)) {
1004	dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_in=%d\n",
1005	pdsm, pkg->nd_size_in);
1006	return -EINVAL;
1007	}
1008
1009	/* If pdsm wants to return data, then ensure that size_out matches */
1010	if (pdsc->size_out &&
1011	pkg->nd_size_out != (pdsc->size_out + ND_PDSM_HDR_SIZE)) {
1012	dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_out=%d\n",
1013	pdsm, pkg->nd_size_out);
1014	return -EINVAL;
1015	}
1016
1017	/* Service the pdsm */
1018	if (pdsc->service) {
1019	dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Servicing..\n", pdsm);
1020
1021	rc = pdsc->service(p, &pdsm_pkg->payload);
1022
1023	if (rc < 0) {
1024	/* error encountered while servicing pdsm */
1025	pdsm_pkg->cmd_status = rc;
1026	pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
1027	} else {
1028	/* pdsm serviced and 'rc' bytes written to payload */
1029	pdsm_pkg->cmd_status = 0;
1030	pkg->nd_fw_size = ND_PDSM_HDR_SIZE + rc;
1031	}
1032	} else {
1033	dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Unsupported PDSM request\n",
1034	pdsm);
1035	pdsm_pkg->cmd_status = -ENOENT;
1036	pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
1037	}
1038
1039	return pdsm_pkg->cmd_status;
1040	}
1041
1042	static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
1043	struct nvdimm *nvdimm, unsigned int cmd, void *buf,
1044	unsigned int buf_len, int *cmd_rc)
1045	{
1046	struct nd_cmd_get_config_size *get_size_hdr;
1047	struct nd_cmd_pkg *call_pkg = NULL;
1048	struct papr_scm_priv *p;
1049	int rc;
1050
1051	rc = is_cmd_valid(nvdimm, cmd, buf, buf_len);
1052	if (rc) {
1053	pr_debug("Invalid cmd=0x%x. Err=%d\n", cmd, rc);
1054	return rc;
1055	}
1056
1057	/* Use a local variable in case cmd_rc pointer is NULL */
1058	if (!cmd_rc)
1059	cmd_rc = &rc;
1060
1061	p = nvdimm_provider_data(nvdimm);
1062
1063	switch (cmd) {
1064	case ND_CMD_GET_CONFIG_SIZE:
1065	get_size_hdr = buf;
1066
1067	get_size_hdr->status = 0;
1068	get_size_hdr->max_xfer = 8;
1069	get_size_hdr->config_size = p->metadata_size;
1070	*cmd_rc = 0;
1071	break;
1072
1073	case ND_CMD_GET_CONFIG_DATA:
1074	*cmd_rc = papr_scm_meta_get(p, hdr: buf);
1075	break;
1076
1077	case ND_CMD_SET_CONFIG_DATA:
1078	*cmd_rc = papr_scm_meta_set(p, hdr: buf);
1079	break;
1080
1081	case ND_CMD_CALL:
1082	call_pkg = (struct nd_cmd_pkg *)buf;
1083	*cmd_rc = papr_scm_service_pdsm(p, pkg: call_pkg);
1084	break;
1085
1086	default:
1087	dev_dbg(&p->pdev->dev, "Unknown command = %d\n", cmd);
1088	return -EINVAL;
1089	}
1090
1091	dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);
1092
1093	return 0;
1094	}
1095
1096	static ssize_t health_bitmap_inject_show(struct device *dev,
1097	struct device_attribute *attr,
1098	char *buf)
1099	{
1100	struct nvdimm *dimm = to_nvdimm(dev);
1101	struct papr_scm_priv *p = nvdimm_provider_data(nvdimm: dimm);
1102
1103	return sprintf(buf, fmt: "%#llx\n",
1104	READ_ONCE(p->health_bitmap_inject_mask));
1105	}
1106
1107	static DEVICE_ATTR_ADMIN_RO(health_bitmap_inject);
1108
1109	static ssize_t perf_stats_show(struct device *dev,
1110	struct device_attribute *attr, char *buf)
1111	{
1112	int index;
1113	ssize_t rc;
1114	struct seq_buf s;
1115	struct papr_scm_perf_stat *stat;
1116	struct papr_scm_perf_stats *stats;
1117	struct nvdimm *dimm = to_nvdimm(dev);
1118	struct papr_scm_priv *p = nvdimm_provider_data(nvdimm: dimm);
1119
1120	if (!p->stat_buffer_len)
1121	return -ENOENT;
1122
1123	/* Allocate the buffer for phyp where stats are written */
1124	stats = kzalloc(size: p->stat_buffer_len, GFP_KERNEL);
1125	if (!stats)
1126	return -ENOMEM;
1127
1128	/* Ask phyp to return all dimm perf stats */
1129	rc = drc_pmem_query_stats(p, buff_stats: stats, num_stats: 0);
1130	if (rc)
1131	goto free_stats;
1132	/*
1133	* Go through the returned output buffer and print stats and
1134	* values. Since stat_id is essentially a char string of
1135	* 8 bytes, simply use the string format specifier to print it.
1136	*/
1137	seq_buf_init(s: &s, buf, PAGE_SIZE);
1138	for (index = 0, stat = stats->scm_statistic;
1139	index < be32_to_cpu(stats->num_statistics);
1140	++index, ++stat) {
1141	seq_buf_printf(s: &s, fmt: "%.8s = 0x%016llX\n",
1142	stat->stat_id,
1143	be64_to_cpu(stat->stat_val));
1144	}
1145
1146	free_stats:
1147	kfree(objp: stats);
1148	return rc ? rc : (ssize_t)seq_buf_used(s: &s);
1149	}
1150	static DEVICE_ATTR_ADMIN_RO(perf_stats);
1151
1152	static ssize_t flags_show(struct device *dev,
1153	struct device_attribute *attr, char *buf)
1154	{
1155	struct nvdimm *dimm = to_nvdimm(dev);
1156	struct papr_scm_priv *p = nvdimm_provider_data(nvdimm: dimm);
1157	struct seq_buf s;
1158	u64 health;
1159	int rc;
1160
1161	rc = drc_pmem_query_health(p);
1162	if (rc)
1163	return rc;
1164
1165	/* Copy health_bitmap locally, check masks & update out buffer */
1166	health = READ_ONCE(p->health_bitmap);
1167
1168	seq_buf_init(s: &s, buf, PAGE_SIZE);
1169	if (health & PAPR_PMEM_UNARMED_MASK)
1170	seq_buf_printf(s: &s, fmt: "not_armed ");
1171
1172	if (health & PAPR_PMEM_BAD_SHUTDOWN_MASK)
1173	seq_buf_printf(s: &s, fmt: "flush_fail ");
1174
1175	if (health & PAPR_PMEM_BAD_RESTORE_MASK)
1176	seq_buf_printf(s: &s, fmt: "restore_fail ");
1177
1178	if (health & PAPR_PMEM_ENCRYPTED)
1179	seq_buf_printf(s: &s, fmt: "encrypted ");
1180
1181	if (health & PAPR_PMEM_SMART_EVENT_MASK)
1182	seq_buf_printf(s: &s, fmt: "smart_notify ");
1183
1184	if (health & PAPR_PMEM_SCRUBBED_AND_LOCKED)
1185	seq_buf_printf(s: &s, fmt: "scrubbed locked ");
1186
1187	if (seq_buf_used(s: &s))
1188	seq_buf_printf(s: &s, fmt: "\n");
1189
1190	return seq_buf_used(s: &s);
1191	}
1192	DEVICE_ATTR_RO(flags);
1193
1194	static ssize_t dirty_shutdown_show(struct device *dev,
1195	struct device_attribute *attr, char *buf)
1196	{
1197	struct nvdimm *dimm = to_nvdimm(dev);
1198	struct papr_scm_priv *p = nvdimm_provider_data(nvdimm: dimm);
1199
1200	return sysfs_emit(buf, fmt: "%llu\n", p->dirty_shutdown_counter);
1201	}
1202	DEVICE_ATTR_RO(dirty_shutdown);
1203
1204	static umode_t papr_nd_attribute_visible(struct kobject *kobj,
1205	struct attribute *attr, int n)
1206	{
1207	struct device *dev = kobj_to_dev(kobj);
1208	struct nvdimm *nvdimm = to_nvdimm(dev);
1209	struct papr_scm_priv *p = nvdimm_provider_data(nvdimm);
1210
1211	/* For if perf-stats not available remove perf_stats sysfs */
1212	if (attr == &dev_attr_perf_stats.attr && p->stat_buffer_len == 0)
1213	return 0;
1214
1215	return attr->mode;
1216	}
1217
1218	/* papr_scm specific dimm attributes */
1219	static struct attribute *papr_nd_attributes[] = {
1220	&dev_attr_flags.attr,
1221	&dev_attr_perf_stats.attr,
1222	&dev_attr_dirty_shutdown.attr,
1223	&dev_attr_health_bitmap_inject.attr,
1224	NULL,
1225	};
1226
1227	static const struct attribute_group papr_nd_attribute_group = {
1228	.name = "papr",
1229	.is_visible = papr_nd_attribute_visible,
1230	.attrs = papr_nd_attributes,
1231	};
1232
1233	static const struct attribute_group *papr_nd_attr_groups[] = {
1234	&papr_nd_attribute_group,
1235	NULL,
1236	};
1237
1238	static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
1239	{
1240	struct device *dev = &p->pdev->dev;
1241	struct nd_mapping_desc mapping;
1242	struct nd_region_desc ndr_desc;
1243	unsigned long dimm_flags;
1244	int target_nid, online_nid;
1245
1246	p->bus_desc.ndctl = papr_scm_ndctl;
1247	p->bus_desc.module = THIS_MODULE;
1248	p->bus_desc.of_node = p->pdev->dev.of_node;
1249	p->bus_desc.provider_name = kstrdup(s: p->pdev->name, GFP_KERNEL);
1250
1251	/* Set the dimm command family mask to accept PDSMs */
1252	set_bit(NVDIMM_FAMILY_PAPR, addr: &p->bus_desc.dimm_family_mask);
1253
1254	if (!p->bus_desc.provider_name)
1255	return -ENOMEM;
1256
1257	p->bus = nvdimm_bus_register(NULL, nfit_desc: &p->bus_desc);
1258	if (!p->bus) {
1259	dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
1260	kfree(objp: p->bus_desc.provider_name);
1261	return -ENXIO;
1262	}
1263
1264	dimm_flags = 0;
1265	set_bit(nr: NDD_LABELING, addr: &dimm_flags);
1266
1267	/*
1268	* Check if the nvdimm is unarmed. No locking needed as we are still
1269	* initializing. Ignore error encountered if any.
1270	*/
1271	__drc_pmem_query_health(p);
1272
1273	if (p->health_bitmap & PAPR_PMEM_UNARMED_MASK)
1274	set_bit(nr: NDD_UNARMED, addr: &dimm_flags);
1275
1276	p->nvdimm = nvdimm_create(nvdimm_bus: p->bus, provider_data: p, groups: papr_nd_attr_groups,
1277	flags: dimm_flags, PAPR_SCM_DIMM_CMD_MASK, num_flush: 0, NULL);
1278	if (!p->nvdimm) {
1279	dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
1280	goto err;
1281	}
1282
1283	if (nvdimm_bus_check_dimm_count(nvdimm_bus: p->bus, dimm_count: 1))
1284	goto err;
1285
1286	/* now add the region */
1287
1288	memset(&mapping, 0, sizeof(mapping));
1289	mapping.nvdimm = p->nvdimm;
1290	mapping.start = 0;
1291	mapping.size = p->blocks * p->block_size; // XXX: potential overflow?
1292
1293	memset(&ndr_desc, 0, sizeof(ndr_desc));
1294	target_nid = dev_to_node(dev: &p->pdev->dev);
1295	online_nid = numa_map_to_online_node(target_nid);
1296	ndr_desc.numa_node = online_nid;
1297	ndr_desc.target_node = target_nid;
1298	ndr_desc.res = &p->res;
1299	ndr_desc.of_node = p->dn;
1300	ndr_desc.provider_data = p;
1301	ndr_desc.mapping = &mapping;
1302	ndr_desc.num_mappings = 1;
1303	ndr_desc.nd_set = &p->nd_set;
1304
1305	if (p->hcall_flush_required) {
1306	set_bit(nr: ND_REGION_ASYNC, addr: &ndr_desc.flags);
1307	ndr_desc.flush = papr_scm_pmem_flush;
1308	}
1309
1310	if (p->is_volatile)
1311	p->region = nvdimm_volatile_region_create(nvdimm_bus: p->bus, ndr_desc: &ndr_desc);
1312	else {
1313	set_bit(nr: ND_REGION_PERSIST_MEMCTRL, addr: &ndr_desc.flags);
1314	p->region = nvdimm_pmem_region_create(nvdimm_bus: p->bus, ndr_desc: &ndr_desc);
1315	}
1316	if (!p->region) {
1317	dev_err(dev, "Error registering region %pR from %pOF\n",
1318	ndr_desc.res, p->dn);
1319	goto err;
1320	}
1321	if (target_nid != online_nid)
1322	dev_info(dev, "Region registered with target node %d and online node %d",
1323	target_nid, online_nid);
1324
1325	mutex_lock(&papr_ndr_lock);
1326	list_add_tail(new: &p->region_list, head: &papr_nd_regions);
1327	mutex_unlock(lock: &papr_ndr_lock);
1328
1329	return 0;
1330
1331	err: nvdimm_bus_unregister(nvdimm_bus: p->bus);
1332	kfree(objp: p->bus_desc.provider_name);
1333	return -ENXIO;
1334	}
1335
1336	static void papr_scm_add_badblock(struct nd_region *region,
1337	struct nvdimm_bus *bus, u64 phys_addr)
1338	{
1339	u64 aligned_addr = ALIGN_DOWN(phys_addr, L1_CACHE_BYTES);
1340
1341	if (nvdimm_bus_add_badrange(nvdimm_bus: bus, addr: aligned_addr, L1_CACHE_BYTES)) {
1342	pr_err("Bad block registration for 0x%llx failed\n", phys_addr);
1343	return;
1344	}
1345
1346	pr_debug("Add memory range (0x%llx - 0x%llx) as bad range\n",
1347	aligned_addr, aligned_addr + L1_CACHE_BYTES);
1348
1349	nvdimm_region_notify(nd_region: region, event: NVDIMM_REVALIDATE_POISON);
1350	}
1351
1352	static int handle_mce_ue(struct notifier_block *nb, unsigned long val,
1353	void *data)
1354	{
1355	struct machine_check_event *evt = data;
1356	struct papr_scm_priv *p;
1357	u64 phys_addr;
1358	bool found = false;
1359
1360	if (evt->error_type != MCE_ERROR_TYPE_UE)
1361	return NOTIFY_DONE;
1362
1363	if (list_empty(head: &papr_nd_regions))
1364	return NOTIFY_DONE;
1365
1366	/*
1367	* The physical address obtained here is PAGE_SIZE aligned, so get the
1368	* exact address from the effective address
1369	*/
1370	phys_addr = evt->u.ue_error.physical_address +
1371	(evt->u.ue_error.effective_address & ~PAGE_MASK);
1372
1373	if (!evt->u.ue_error.physical_address_provided ||
1374	!is_zone_device_page(pfn_to_page(phys_addr >> PAGE_SHIFT)))
1375	return NOTIFY_DONE;
1376
1377	/* mce notifier is called from a process context, so mutex is safe */
1378	mutex_lock(&papr_ndr_lock);
1379	list_for_each_entry(p, &papr_nd_regions, region_list) {
1380	if (phys_addr >= p->res.start && phys_addr <= p->res.end) {
1381	found = true;
1382	break;
1383	}
1384	}
1385
1386	if (found)
1387	papr_scm_add_badblock(region: p->region, bus: p->bus, phys_addr);
1388
1389	mutex_unlock(lock: &papr_ndr_lock);
1390
1391	return found ? NOTIFY_OK : NOTIFY_DONE;
1392	}
1393
1394	static struct notifier_block mce_ue_nb = {
1395	.notifier_call = handle_mce_ue
1396	};
1397
1398	static int papr_scm_probe(struct platform_device *pdev)
1399	{
1400	struct device_node *dn = pdev->dev.of_node;
1401	u32 drc_index, metadata_size;
1402	u64 blocks, block_size;
1403	struct papr_scm_priv *p;
1404	u8 uuid_raw[UUID_SIZE];
1405	const char *uuid_str;
1406	ssize_t stat_size;
1407	uuid_t uuid;
1408	int rc;
1409
1410	/* check we have all the required DT properties */
1411	if (of_property_read_u32(np: dn, propname: "ibm,my-drc-index", out_value: &drc_index)) {
1412	dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
1413	return -ENODEV;
1414	}
1415
1416	if (of_property_read_u64(np: dn, propname: "ibm,block-size", out_value: &block_size)) {
1417	dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
1418	return -ENODEV;
1419	}
1420
1421	if (of_property_read_u64(np: dn, propname: "ibm,number-of-blocks", out_value: &blocks)) {
1422	dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
1423	return -ENODEV;
1424	}
1425
1426	if (of_property_read_string(np: dn, propname: "ibm,unit-guid", out_string: &uuid_str)) {
1427	dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
1428	return -ENODEV;
1429	}
1430
1431	/*
1432	* open firmware platform device create won't update the NUMA
1433	* distance table. For PAPR SCM devices we use numa_map_to_online_node()
1434	* to find the nearest online NUMA node and that requires correct
1435	* distance table information.
1436	*/
1437	update_numa_distance(dn);
1438
1439	p = kzalloc(size: sizeof(*p), GFP_KERNEL);
1440	if (!p)
1441	return -ENOMEM;
1442
1443	/* Initialize the dimm mutex */
1444	mutex_init(&p->health_mutex);
1445
1446	/* optional DT properties */
1447	of_property_read_u32(np: dn, propname: "ibm,metadata-size", out_value: &metadata_size);
1448
1449	p->dn = dn;
1450	p->drc_index = drc_index;
1451	p->block_size = block_size;
1452	p->blocks = blocks;
1453	p->is_volatile = !of_property_read_bool(np: dn, propname: "ibm,cache-flush-required");
1454	p->hcall_flush_required = of_property_read_bool(np: dn, propname: "ibm,hcall-flush-required");
1455
1456	if (of_property_read_u64(np: dn, propname: "ibm,persistence-failed-count",
1457	out_value: &p->dirty_shutdown_counter))
1458	p->dirty_shutdown_counter = 0;
1459
1460	/* We just need to ensure that set cookies are unique across */
1461	uuid_parse(uuid: uuid_str, u: &uuid);
1462
1463	/*
1464	* The cookie1 and cookie2 are not really little endian.
1465	* We store a raw buffer representation of the
1466	* uuid string so that we can compare this with the label
1467	* area cookie irrespective of the endian configuration
1468	* with which the kernel is built.
1469	*
1470	* Historically we stored the cookie in the below format.
1471	* for a uuid string 72511b67-0b3b-42fd-8d1d-5be3cae8bcaa
1472	* cookie1 was 0xfd423b0b671b5172
1473	* cookie2 was 0xaabce8cae35b1d8d
1474	*/
1475	export_uuid(dst: uuid_raw, src: &uuid);
1476	p->nd_set.cookie1 = get_unaligned_le64(p: &uuid_raw[0]);
1477	p->nd_set.cookie2 = get_unaligned_le64(p: &uuid_raw[8]);
1478
1479	/* might be zero */
1480	p->metadata_size = metadata_size;
1481	p->pdev = pdev;
1482
1483	/* request the hypervisor to bind this region to somewhere in memory */
1484	rc = drc_pmem_bind(p);
1485
1486	/* If phyp says drc memory still bound then force unbound and retry */
1487	if (rc == H_OVERLAP)
1488	rc = drc_pmem_query_n_bind(p);
1489
1490	if (rc != H_SUCCESS) {
1491	dev_err(&p->pdev->dev, "bind err: %d\n", rc);
1492	rc = -ENXIO;
1493	goto err;
1494	}
1495
1496	/* setup the resource for the newly bound range */
1497	p->res.start = p->bound_addr;
1498	p->res.end = p->bound_addr + p->blocks * p->block_size - 1;
1499	p->res.name = pdev->name;
1500	p->res.flags = IORESOURCE_MEM;
1501
1502	/* Try retrieving the stat buffer and see if its supported */
1503	stat_size = drc_pmem_query_stats(p, NULL, num_stats: 0);
1504	if (stat_size > 0) {
1505	p->stat_buffer_len = stat_size;
1506	dev_dbg(&p->pdev->dev, "Max perf-stat size %lu-bytes\n",
1507	p->stat_buffer_len);
1508	}
1509
1510	rc = papr_scm_nvdimm_init(p);
1511	if (rc)
1512	goto err2;
1513
1514	platform_set_drvdata(pdev, data: p);
1515	papr_scm_pmu_register(p);
1516
1517	return 0;
1518
1519	err2: drc_pmem_unbind(p);
1520	err: kfree(objp: p);
1521	return rc;
1522	}
1523
1524	static int papr_scm_remove(struct platform_device *pdev)
1525	{
1526	struct papr_scm_priv *p = platform_get_drvdata(pdev);
1527
1528	mutex_lock(&papr_ndr_lock);
1529	list_del(entry: &p->region_list);
1530	mutex_unlock(lock: &papr_ndr_lock);
1531
1532	nvdimm_bus_unregister(nvdimm_bus: p->bus);
1533	drc_pmem_unbind(p);
1534
1535	if (pdev->archdata.priv)
1536	unregister_nvdimm_pmu(nd_pmu: pdev->archdata.priv);
1537
1538	pdev->archdata.priv = NULL;
1539	kfree(objp: p->bus_desc.provider_name);
1540	kfree(objp: p);
1541
1542	return 0;
1543	}
1544
1545	static const struct of_device_id papr_scm_match[] = {
1546	{ .compatible = "ibm,pmemory" },
1547	{ .compatible = "ibm,pmemory-v2" },
1548	{ },
1549	};
1550
1551	static struct platform_driver papr_scm_driver = {
1552	.probe = papr_scm_probe,
1553	.remove = papr_scm_remove,
1554	.driver = {
1555	.name = "papr_scm",
1556	.of_match_table = papr_scm_match,
1557	},
1558	};
1559
1560	static int __init papr_scm_init(void)
1561	{
1562	int ret;
1563
1564	ret = platform_driver_register(&papr_scm_driver);
1565	if (!ret)
1566	mce_register_notifier(&mce_ue_nb);
1567
1568	return ret;
1569	}
1570	module_init(papr_scm_init);
1571
1572	static void __exit papr_scm_exit(void)
1573	{
1574	mce_unregister_notifier(&mce_ue_nb);
1575	platform_driver_unregister(&papr_scm_driver);
1576	}
1577	module_exit(papr_scm_exit);
1578
1579	MODULE_DEVICE_TABLE(of, papr_scm_match);
1580	MODULE_LICENSE("GPL");
1581	MODULE_AUTHOR("IBM Corporation");
1582