summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms/pseries/papr_scm.c
blob: 9c569078a09fd3c8564e46c0af6d5f4a798c222b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
// SPDX-License-Identifier: GPL-2.0

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

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

#include <asm/plpar_wrappers.h>
#include <asm/papr_pdsm.h>

#define BIND_ANY_ADDR (~0ul)

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

/* DIMM health bitmap bitmap indicators */
/* SCM device is unable to persist memory contents */
#define PAPR_PMEM_UNARMED                   (1ULL << (63 - 0))
/* SCM device failed to persist memory contents */
#define PAPR_PMEM_SHUTDOWN_DIRTY            (1ULL << (63 - 1))
/* SCM device contents are persisted from previous IPL */
#define PAPR_PMEM_SHUTDOWN_CLEAN            (1ULL << (63 - 2))
/* SCM device contents are not persisted from previous IPL */
#define PAPR_PMEM_EMPTY                     (1ULL << (63 - 3))
/* SCM device memory life remaining is critically low */
#define PAPR_PMEM_HEALTH_CRITICAL           (1ULL << (63 - 4))
/* SCM device will be garded off next IPL due to failure */
#define PAPR_PMEM_HEALTH_FATAL              (1ULL << (63 - 5))
/* SCM contents cannot persist due to current platform health status */
#define PAPR_PMEM_HEALTH_UNHEALTHY          (1ULL << (63 - 6))
/* SCM device is unable to persist memory contents in certain conditions */
#define PAPR_PMEM_HEALTH_NON_CRITICAL       (1ULL << (63 - 7))
/* SCM device is encrypted */
#define PAPR_PMEM_ENCRYPTED                 (1ULL << (63 - 8))
/* SCM device has been scrubbed and locked */
#define PAPR_PMEM_SCRUBBED_AND_LOCKED       (1ULL << (63 - 9))

/* Bits status indicators for health bitmap indicating unarmed dimm */
#define PAPR_PMEM_UNARMED_MASK (PAPR_PMEM_UNARMED |		\
				PAPR_PMEM_HEALTH_UNHEALTHY)

/* Bits status indicators for health bitmap indicating unflushed dimm */
#define PAPR_PMEM_BAD_SHUTDOWN_MASK (PAPR_PMEM_SHUTDOWN_DIRTY)

/* Bits status indicators for health bitmap indicating unrestored dimm */
#define PAPR_PMEM_BAD_RESTORE_MASK  (PAPR_PMEM_EMPTY)

/* Bit status indicators for smart event notification */
#define PAPR_PMEM_SMART_EVENT_MASK (PAPR_PMEM_HEALTH_CRITICAL | \
				    PAPR_PMEM_HEALTH_FATAL |	\
				    PAPR_PMEM_HEALTH_UNHEALTHY)

/* private struct associated with each region */
struct papr_scm_priv {
	struct platform_device *pdev;
	struct device_node *dn;
	uint32_t drc_index;
	uint64_t blocks;
	uint64_t block_size;
	int metadata_size;
	bool is_volatile;

	uint64_t bound_addr;

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

	/* Protect dimm health data from concurrent read/writes */
	struct mutex health_mutex;

	/* Last time the health information of the dimm was updated */
	unsigned long lasthealth_jiffies;

	/* Health information for the dimm */
	u64 health_bitmap;
};

static int drc_pmem_bind(struct papr_scm_priv *p)
{
	unsigned long ret[PLPAR_HCALL_BUFSIZE];
	uint64_t saved = 0;
	uint64_t token;
	int64_t rc;

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

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

	if (rc)
		return rc;

	p->bound_addr = saved;
	dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n",
		p->drc_index, (unsigned long)saved);
	return rc;
}

static void drc_pmem_unbind(struct papr_scm_priv *p)
{
	unsigned long ret[PLPAR_HCALL_BUFSIZE];
	uint64_t token = 0;
	int64_t rc;

	dev_dbg(&p->pdev->dev, "unbind drc 0x%x\n", p->drc_index);

	/* NB: unbind has the same retry requirements as drc_pmem_bind() */
	do {

		/* Unbind of all SCM resources associated with drcIndex */
		rc = plpar_hcall(H_SCM_UNBIND_ALL, ret, H_UNBIND_SCOPE_DRC,
				 p->drc_index, token);
		token = ret[0];

		/* Check if we are stalled for some time */
		if (H_IS_LONG_BUSY(rc)) {
			msleep(get_longbusy_msecs(rc));
			rc = H_BUSY;
		} else if (rc == H_BUSY) {
			cond_resched();
		}

	} while (rc == H_BUSY);

	if (rc)
		dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);
	else
		dev_dbg(&p->pdev->dev, "unbind drc 0x%x complete\n",
			p->drc_index);

	return;
}

static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
{
	unsigned long start_addr;
	unsigned long end_addr;
	unsigned long ret[PLPAR_HCALL_BUFSIZE];
	int64_t rc;


	rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
			 p->drc_index, 0);
	if (rc)
		goto err_out;
	start_addr = ret[0];

	/* Make sure the full region is bound. */
	rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
			 p->drc_index, p->blocks - 1);
	if (rc)
		goto err_out;
	end_addr = ret[0];

	if ((end_addr - start_addr) != ((p->blocks - 1) * p->block_size))
		goto err_out;

	p->bound_addr = start_addr;
	dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n", p->drc_index, start_addr);
	return rc;

err_out:
	dev_info(&p->pdev->dev,
		 "Failed to query, trying an unbind followed by bind");
	drc_pmem_unbind(p);
	return drc_pmem_bind(p);
}

/*
 * Issue hcall to retrieve dimm health info and populate papr_scm_priv with the
 * health information.
 */
static int __drc_pmem_query_health(struct papr_scm_priv *p)
{
	unsigned long ret[PLPAR_HCALL_BUFSIZE];
	long rc;

	/* issue the hcall */
	rc = plpar_hcall(H_SCM_HEALTH, ret, p->drc_index);
	if (rc != H_SUCCESS) {
		dev_err(&p->pdev->dev,
			"Failed to query health information, Err:%ld\n", rc);
		return -ENXIO;
	}

	p->lasthealth_jiffies = jiffies;
	p->health_bitmap = ret[0] & ret[1];

	dev_dbg(&p->pdev->dev,
		"Queried dimm health info. Bitmap:0x%016lx Mask:0x%016lx\n",
		ret[0], ret[1]);

	return 0;
}

/* Min interval in seconds for assuming stable dimm health */
#define MIN_HEALTH_QUERY_INTERVAL 60

/* Query cached health info and if needed call drc_pmem_query_health */
static int drc_pmem_query_health(struct papr_scm_priv *p)
{
	unsigned long cache_timeout;
	int rc;

	/* Protect concurrent modifications to papr_scm_priv */
	rc = mutex_lock_interruptible(&p->health_mutex);
	if (rc)
		return rc;

	/* Jiffies offset for which the health data is assumed to be same */
	cache_timeout = p->lasthealth_jiffies +
		msecs_to_jiffies(MIN_HEALTH_QUERY_INTERVAL * 1000);

	/* Fetch new health info is its older than MIN_HEALTH_QUERY_INTERVAL */
	if (time_after(jiffies, cache_timeout))
		rc = __drc_pmem_query_health(p);
	else
		/* Assume cached health data is valid */
		rc = 0;

	mutex_unlock(&p->health_mutex);
	return rc;
}

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

	if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
		return -EINVAL;

	for (len = hdr->in_length; len; len -= read) {

		data_offset = hdr->in_length - len;
		offset = hdr->in_offset + data_offset;

		if (len >= 8)
			read = 8;
		else if (len >= 4)
			read = 4;
		else if (len >= 2)
			read = 2;
		else
			read = 1;

		ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
				  offset, read);

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

		switch (read) {
		case 8:
			*(uint64_t *)(hdr->out_buf + data_offset) = be64_to_cpu(data[0]);
			break;
		case 4:
			*(uint32_t *)(hdr->out_buf + data_offset) = be32_to_cpu(data[0] & 0xffffffff);
			break;

		case 2:
			*(uint16_t *)(hdr->out_buf + data_offset) = be16_to_cpu(data[0] & 0xffff);
			break;

		case 1:
			*(uint8_t *)(hdr->out_buf + data_offset) = (data[0] & 0xff);
			break;
		}
	}
	return 0;
}

static int papr_scm_meta_set(struct papr_scm_priv *p,
			     struct nd_cmd_set_config_hdr *hdr)
{
	unsigned long offset, data_offset;
	int len, wrote;
	unsigned long data;
	__be64 data_be;
	int64_t ret;

	if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
		return -EINVAL;

	for (len = hdr->in_length; len; len -= wrote) {

		data_offset = hdr->in_length - len;
		offset = hdr->in_offset + data_offset;

		if (len >= 8) {
			data = *(uint64_t *)(hdr->in_buf + data_offset);
			data_be = cpu_to_be64(data);
			wrote = 8;
		} else if (len >= 4) {
			data = *(uint32_t *)(hdr->in_buf + data_offset);
			data &= 0xffffffff;
			data_be = cpu_to_be32(data);
			wrote = 4;
		} else if (len >= 2) {
			data = *(uint16_t *)(hdr->in_buf + data_offset);
			data &= 0xffff;
			data_be = cpu_to_be16(data);
			wrote = 2;
		} else {
			data_be = *(uint8_t *)(hdr->in_buf + data_offset);
			data_be &= 0xff;
			wrote = 1;
		}

		ret = plpar_hcall_norets(H_SCM_WRITE_METADATA, p->drc_index,
					 offset, data_be, wrote);
		if (ret == H_PARAMETER) /* bad DRC index */
			return -ENODEV;
		if (ret)
			return -EINVAL; /* other invalid parameter */
	}

	return 0;
}

/*
 * Do a sanity checks on the inputs args to dimm-control function and return
 * '0' if valid. Validation of PDSM payloads happens later in
 * papr_scm_service_pdsm.
 */
static int is_cmd_valid(struct nvdimm *nvdimm, unsigned int cmd, void *buf,
			unsigned int buf_len)
{
	unsigned long cmd_mask = PAPR_SCM_DIMM_CMD_MASK;
	struct nd_cmd_pkg *nd_cmd;
	struct papr_scm_priv *p;
	enum papr_pdsm pdsm;

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

	/* get the provider data from struct nvdimm */
	p = nvdimm_provider_data(nvdimm);

	if (!test_bit(cmd, &cmd_mask)) {
		dev_dbg(&p->pdev->dev, "Unsupported cmd=%u\n", cmd);
		return -EINVAL;
	}

	/* For CMD_CALL verify pdsm request */
	if (cmd == ND_CMD_CALL) {
		/* Verify the envelope and envelop size */
		if (!buf ||
		    buf_len < (sizeof(struct nd_cmd_pkg) + ND_PDSM_HDR_SIZE)) {
			dev_dbg(&p->pdev->dev, "Invalid pkg size=%u\n",
				buf_len);
			return -EINVAL;
		}

		/* Verify that the nd_cmd_pkg.nd_family is correct */
		nd_cmd = (struct nd_cmd_pkg *)buf;

		if (nd_cmd->nd_family != NVDIMM_FAMILY_PAPR) {
			dev_dbg(&p->pdev->dev, "Invalid pkg family=0x%llx\n",
				nd_cmd->nd_family);
			return -EINVAL;
		}

		pdsm = (enum papr_pdsm)nd_cmd->nd_command;

		/* Verify if the pdsm command is valid */
		if (pdsm <= PAPR_PDSM_MIN || pdsm >= PAPR_PDSM_MAX) {
			dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid PDSM\n",
				pdsm);
			return -EINVAL;
		}

		/* Have enough space to hold returned 'nd_pkg_pdsm' header */
		if (nd_cmd->nd_size_out < ND_PDSM_HDR_SIZE) {
			dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid payload\n",
				pdsm);
			return -EINVAL;
		}
	}

	/* Let the command be further processed */
	return 0;
}

/* Fetch the DIMM health info and populate it in provided package. */
static int papr_pdsm_health(struct papr_scm_priv *p,
			    union nd_pdsm_payload *payload)
{
	int rc;

	/* Ensure dimm health mutex is taken preventing concurrent access */
	rc = mutex_lock_interruptible(&p->health_mutex);
	if (rc)
		goto out;

	/* Always fetch upto date dimm health data ignoring cached values */
	rc = __drc_pmem_query_health(p);
	if (rc) {
		mutex_unlock(&p->health_mutex);
		goto out;
	}

	/* update health struct with various flags derived from health bitmap */
	payload->health = (struct nd_papr_pdsm_health) {
		.extension_flags = 0,
		.dimm_unarmed = !!(p->health_bitmap & PAPR_PMEM_UNARMED_MASK),
		.dimm_bad_shutdown = !!(p->health_bitmap & PAPR_PMEM_BAD_SHUTDOWN_MASK),
		.dimm_bad_restore = !!(p->health_bitmap & PAPR_PMEM_BAD_RESTORE_MASK),
		.dimm_scrubbed = !!(p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED),
		.dimm_locked = !!(p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED),
		.dimm_encrypted = !!(p->health_bitmap & PAPR_PMEM_ENCRYPTED),
		.dimm_health = PAPR_PDSM_DIMM_HEALTHY,
	};

	/* Update field dimm_health based on health_bitmap flags */
	if (p->health_bitmap & PAPR_PMEM_HEALTH_FATAL)
		payload->health.dimm_health = PAPR_PDSM_DIMM_FATAL;
	else if (p->health_bitmap & PAPR_PMEM_HEALTH_CRITICAL)
		payload->health.dimm_health = PAPR_PDSM_DIMM_CRITICAL;
	else if (p->health_bitmap & PAPR_PMEM_HEALTH_UNHEALTHY)
		payload->health.dimm_health = PAPR_PDSM_DIMM_UNHEALTHY;

	/* struct populated hence can release the mutex now */
	mutex_unlock(&p->health_mutex);
	rc = sizeof(struct nd_papr_pdsm_health);

out:
	return rc;
}

/*
 * 'struct pdsm_cmd_desc'
 * Identifies supported PDSMs' expected length of in/out payloads
 * and pdsm service function.
 *
 * size_in	: Size of input payload if any in the PDSM request.
 * size_out	: Size of output payload if any in the PDSM request.
 * service	: Service function for the PDSM request. Return semantics:
 *		  rc < 0 : Error servicing PDSM and rc indicates the error.
 *		  rc >=0 : Serviced successfully and 'rc' indicate number of
 *			bytes written to payload.
 */
struct pdsm_cmd_desc {
	u32 size_in;
	u32 size_out;
	int (*service)(struct papr_scm_priv *dimm,
		       union nd_pdsm_payload *payload);
};

/* Holds all supported PDSMs' command descriptors */
static const struct pdsm_cmd_desc __pdsm_cmd_descriptors[] = {
	[PAPR_PDSM_MIN] = {
		.size_in = 0,
		.size_out = 0,
		.service = NULL,
	},
	/* New PDSM command descriptors to be added below */

	[PAPR_PDSM_HEALTH] = {
		.size_in = 0,
		.size_out = sizeof(struct nd_papr_pdsm_health),
		.service = papr_pdsm_health,
	},
	/* Empty */
	[PAPR_PDSM_MAX] = {
		.size_in = 0,
		.size_out = 0,
		.service = NULL,
	},
};

/* Given a valid pdsm cmd return its command descriptor else return NULL */
static inline const struct pdsm_cmd_desc *pdsm_cmd_desc(enum papr_pdsm cmd)
{
	if (cmd >= 0 || cmd < ARRAY_SIZE(__pdsm_cmd_descriptors))
		return &__pdsm_cmd_descriptors[cmd];

	return NULL;
}

/*
 * For a given pdsm request call an appropriate service function.
 * Returns errors if any while handling the pdsm command package.
 */
static int papr_scm_service_pdsm(struct papr_scm_priv *p,
				 struct nd_cmd_pkg *pkg)
{
	/* Get the PDSM header and PDSM command */
	struct nd_pkg_pdsm *pdsm_pkg = (struct nd_pkg_pdsm *)pkg->nd_payload;
	enum papr_pdsm pdsm = (enum papr_pdsm)pkg->nd_command;
	const struct pdsm_cmd_desc *pdsc;
	int rc;

	/* Fetch corresponding pdsm descriptor for validation and servicing */
	pdsc = pdsm_cmd_desc(pdsm);

	/* Validate pdsm descriptor */
	/* Ensure that reserved fields are 0 */
	if (pdsm_pkg->reserved[0] || pdsm_pkg->reserved[1]) {
		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid reserved field\n",
			pdsm);
		return -EINVAL;
	}

	/* If pdsm expects some input, then ensure that the size_in matches */
	if (pdsc->size_in &&
	    pkg->nd_size_in != (pdsc->size_in + ND_PDSM_HDR_SIZE)) {
		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_in=%d\n",
			pdsm, pkg->nd_size_in);
		return -EINVAL;
	}

	/* If pdsm wants to return data, then ensure that  size_out matches */
	if (pdsc->size_out &&
	    pkg->nd_size_out != (pdsc->size_out + ND_PDSM_HDR_SIZE)) {
		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_out=%d\n",
			pdsm, pkg->nd_size_out);
		return -EINVAL;
	}

	/* Service the pdsm */
	if (pdsc->service) {
		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Servicing..\n", pdsm);

		rc = pdsc->service(p, &pdsm_pkg->payload);

		if (rc < 0) {
			/* error encountered while servicing pdsm */
			pdsm_pkg->cmd_status = rc;
			pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
		} else {
			/* pdsm serviced and 'rc' bytes written to payload */
			pdsm_pkg->cmd_status = 0;
			pkg->nd_fw_size = ND_PDSM_HDR_SIZE + rc;
		}
	} else {
		dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Unsupported PDSM request\n",
			pdsm);
		pdsm_pkg->cmd_status = -ENOENT;
		pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
	}

	return pdsm_pkg->cmd_status;
}

static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
			  struct nvdimm *nvdimm, unsigned int cmd, void *buf,
			  unsigned int buf_len, int *cmd_rc)
{
	struct nd_cmd_get_config_size *get_size_hdr;
	struct nd_cmd_pkg *call_pkg = NULL;
	struct papr_scm_priv *p;
	int rc;

	rc = is_cmd_valid(nvdimm, cmd, buf, buf_len);
	if (rc) {
		pr_debug("Invalid cmd=0x%x. Err=%d\n", cmd, rc);
		return rc;
	}

	/* Use a local variable in case cmd_rc pointer is NULL */
	if (!cmd_rc)
		cmd_rc = &rc;

	p = nvdimm_provider_data(nvdimm);

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

		get_size_hdr->status = 0;
		get_size_hdr->max_xfer = 8;
		get_size_hdr->config_size = p->metadata_size;
		*cmd_rc = 0;
		break;

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

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

	case ND_CMD_CALL:
		call_pkg = (struct nd_cmd_pkg *)buf;
		*cmd_rc = papr_scm_service_pdsm(p, call_pkg);
		break;

	default:
		dev_dbg(&p->pdev->dev, "Unknown command = %d\n", cmd);
		return -EINVAL;
	}

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

	return 0;
}

static ssize_t flags_show(struct device *dev,
			  struct device_attribute *attr, char *buf)
{
	struct nvdimm *dimm = to_nvdimm(dev);
	struct papr_scm_priv *p = nvdimm_provider_data(dimm);
	struct seq_buf s;
	u64 health;
	int rc;

	rc = drc_pmem_query_health(p);
	if (rc)
		return rc;

	/* Copy health_bitmap locally, check masks & update out buffer */
	health = READ_ONCE(p->health_bitmap);

	seq_buf_init(&s, buf, PAGE_SIZE);
	if (health & PAPR_PMEM_UNARMED_MASK)
		seq_buf_printf(&s, "not_armed ");

	if (health & PAPR_PMEM_BAD_SHUTDOWN_MASK)
		seq_buf_printf(&s, "flush_fail ");

	if (health & PAPR_PMEM_BAD_RESTORE_MASK)
		seq_buf_printf(&s, "restore_fail ");

	if (health & PAPR_PMEM_ENCRYPTED)
		seq_buf_printf(&s, "encrypted ");

	if (health & PAPR_PMEM_SMART_EVENT_MASK)
		seq_buf_printf(&s, "smart_notify ");

	if (health & PAPR_PMEM_SCRUBBED_AND_LOCKED)
		seq_buf_printf(&s, "scrubbed locked ");

	if (seq_buf_used(&s))
		seq_buf_printf(&s, "\n");

	return seq_buf_used(&s);
}
DEVICE_ATTR_RO(flags);

/* papr_scm specific dimm attributes */
static struct attribute *papr_nd_attributes[] = {
	&dev_attr_flags.attr,
	NULL,
};

static struct attribute_group papr_nd_attribute_group = {
	.name = "papr",
	.attrs = papr_nd_attributes,
};

static const struct attribute_group *papr_nd_attr_groups[] = {
	&papr_nd_attribute_group,
	NULL,
};

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

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

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

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

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

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

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

	/* now add the region */

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

	memset(&ndr_desc, 0, sizeof(ndr_desc));
	target_nid = dev_to_node(&p->pdev->dev);
	online_nid = numa_map_to_online_node(target_nid);
	ndr_desc.numa_node = online_nid;
	ndr_desc.target_node = target_nid;
	ndr_desc.res = &p->res;
	ndr_desc.of_node = p->dn;
	ndr_desc.provider_data = p;
	ndr_desc.mapping = &mapping;
	ndr_desc.num_mappings = 1;
	ndr_desc.nd_set = &p->nd_set;

	if (p->is_volatile)
		p->region = nvdimm_volatile_region_create(p->bus, &ndr_desc);
	else {
		set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags);
		p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
	}
	if (!p->region) {
		dev_err(dev, "Error registering region %pR from %pOF\n",
				ndr_desc.res, p->dn);
		goto err;
	}
	if (target_nid != online_nid)
		dev_info(dev, "Region registered with target node %d and online node %d",
			 target_nid, online_nid);

	return 0;

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

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

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

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

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

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


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

	/* Initialize the dimm mutex */
	mutex_init(&p->health_mutex);

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

	p->dn = dn;
	p->drc_index = drc_index;
	p->block_size = block_size;
	p->blocks = blocks;
	p->is_volatile = !of_property_read_bool(dn, "ibm,cache-flush-required");

	/* We just need to ensure that set cookies are unique across */
	uuid_parse(uuid_str, (uuid_t *) uuid);
	/*
	 * cookie1 and cookie2 are not really little endian
	 * we store a little endian representation of the
	 * uuid str so that we can compare this with the label
	 * area cookie irrespective of the endian config with which
	 * the kernel is built.
	 */
	p->nd_set.cookie1 = cpu_to_le64(uuid[0]);
	p->nd_set.cookie2 = cpu_to_le64(uuid[1]);

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

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

	/* If phyp says drc memory still bound then force unbound and retry */
	if (rc == H_OVERLAP)
		rc = drc_pmem_query_n_bind(p);

	if (rc != H_SUCCESS) {
		dev_err(&p->pdev->dev, "bind err: %d\n", rc);
		rc = -ENXIO;
		goto err;
	}

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

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

	platform_set_drvdata(pdev, p);

	return 0;

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

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

	nvdimm_bus_unregister(p->bus);
	drc_pmem_unbind(p);
	kfree(p->bus_desc.provider_name);
	kfree(p);

	return 0;
}

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

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

module_platform_driver(papr_scm_driver);
MODULE_DEVICE_TABLE(of, papr_scm_match);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("IBM Corporation");