summaryrefslogtreecommitdiff
path: root/arch/s390/kernel/perf_cpum_cf_diag.c
blob: b6854812d2ed56f11cbd03865c16b26290518611 (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
// SPDX-License-Identifier: GPL-2.0
/*
 * Performance event support for s390x - CPU-measurement Counter Sets
 *
 *  Copyright IBM Corp. 2019
 *  Author(s): Hendrik Brueckner <brueckner@linux.ibm.com>
 *	       Thomas Richer <tmricht@linux.ibm.com>
 */
#define KMSG_COMPONENT	"cpum_cf_diag"
#define pr_fmt(fmt)	KMSG_COMPONENT ": " fmt

#include <linux/kernel.h>
#include <linux/kernel_stat.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/processor.h>

#include <asm/ctl_reg.h>
#include <asm/irq.h>
#include <asm/cpu_mcf.h>
#include <asm/timex.h>
#include <asm/debug.h>

#define	CF_DIAG_CTRSET_DEF		0xfeef	/* Counter set header mark */

static unsigned int cf_diag_cpu_speed;
static debug_info_t *cf_diag_dbg;

struct cf_diag_csd {		/* Counter set data per CPU */
	size_t used;			/* Bytes used in data/start */
	unsigned char start[PAGE_SIZE];	/* Counter set at event start */
	unsigned char data[PAGE_SIZE];	/* Counter set at event delete */
};
DEFINE_PER_CPU(struct cf_diag_csd, cf_diag_csd);

/* Counter sets are stored as data stream in a page sized memory buffer and
 * exported to user space via raw data attached to the event sample data.
 * Each counter set starts with an eight byte header consisting of:
 * - a two byte eye catcher (0xfeef)
 * - a one byte counter set number
 * - a two byte counter set size (indicates the number of counters in this set)
 * - a three byte reserved value (must be zero) to make the header the same
 *   size as a counter value.
 * All counter values are eight byte in size.
 *
 * All counter sets are followed by a 64 byte trailer.
 * The trailer consists of a:
 * - flag field indicating valid fields when corresponding bit set
 * - the counter facility first and second version number
 * - the CPU speed if nonzero
 * - the time stamp the counter sets have been collected
 * - the time of day (TOD) base value
 * - the machine type.
 *
 * The counter sets are saved when the process is prepared to be executed on a
 * CPU and saved again when the process is going to be removed from a CPU.
 * The difference of both counter sets are calculated and stored in the event
 * sample data area.
 */

struct cf_ctrset_entry {	/* CPU-M CF counter set entry (8 byte) */
	unsigned int def:16;	/* 0-15  Data Entry Format */
	unsigned int set:16;	/* 16-31 Counter set identifier */
	unsigned int ctr:16;	/* 32-47 Number of stored counters */
	unsigned int res1:16;	/* 48-63 Reserved */
};

struct cf_trailer_entry {	/* CPU-M CF_DIAG trailer (64 byte) */
	/* 0 - 7 */
	union {
		struct {
			unsigned int clock_base:1;	/* TOD clock base set */
			unsigned int speed:1;		/* CPU speed set */
			/* Measurement alerts */
			unsigned int mtda:1;	/* Loss of MT ctr. data alert */
			unsigned int caca:1;	/* Counter auth. change alert */
			unsigned int lcda:1;	/* Loss of counter data alert */
		};
		unsigned long flags;	/* 0-63    All indicators */
	};
	/* 8 - 15 */
	unsigned int cfvn:16;			/* 64-79   Ctr First Version */
	unsigned int csvn:16;			/* 80-95   Ctr Second Version */
	unsigned int cpu_speed:32;		/* 96-127  CPU speed */
	/* 16 - 23 */
	unsigned long timestamp;		/* 128-191 Timestamp (TOD) */
	/* 24 - 55 */
	union {
		struct {
			unsigned long progusage1;
			unsigned long progusage2;
			unsigned long progusage3;
			unsigned long tod_base;
		};
		unsigned long progusage[4];
	};
	/* 56 - 63 */
	unsigned int mach_type:16;		/* Machine type */
	unsigned int res1:16;			/* Reserved */
	unsigned int res2:32;			/* Reserved */
};

/* Create the trailer data at the end of a page. */
static void cf_diag_trailer(struct cf_trailer_entry *te)
{
	struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
	struct cpuid cpuid;

	te->cfvn = cpuhw->info.cfvn;		/* Counter version numbers */
	te->csvn = cpuhw->info.csvn;

	get_cpu_id(&cpuid);			/* Machine type */
	te->mach_type = cpuid.machine;
	te->cpu_speed = cf_diag_cpu_speed;
	if (te->cpu_speed)
		te->speed = 1;
	te->clock_base = 1;			/* Save clock base */
	memcpy(&te->tod_base, &tod_clock_base[1], 8);
	store_tod_clock((__u64 *)&te->timestamp);
}

/*
 * Change the CPUMF state to active.
 * Enable and activate the CPU-counter sets according
 * to the per-cpu control state.
 */
static void cf_diag_enable(struct pmu *pmu)
{
	struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
	int err;

	debug_sprintf_event(cf_diag_dbg, 5,
			    "%s pmu %p cpu %d flags %#x state %#llx\n",
			    __func__, pmu, smp_processor_id(), cpuhw->flags,
			    cpuhw->state);
	if (cpuhw->flags & PMU_F_ENABLED)
		return;

	err = lcctl(cpuhw->state);
	if (err) {
		pr_err("Enabling the performance measuring unit "
		       "failed with rc=%x\n", err);
		return;
	}
	cpuhw->flags |= PMU_F_ENABLED;
}

/*
 * Change the CPUMF state to inactive.
 * Disable and enable (inactive) the CPU-counter sets according
 * to the per-cpu control state.
 */
static void cf_diag_disable(struct pmu *pmu)
{
	struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
	u64 inactive;
	int err;

	debug_sprintf_event(cf_diag_dbg, 5,
			    "%s pmu %p cpu %d flags %#x state %#llx\n",
			    __func__, pmu, smp_processor_id(), cpuhw->flags,
			    cpuhw->state);
	if (!(cpuhw->flags & PMU_F_ENABLED))
		return;

	inactive = cpuhw->state & ~((1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1);
	err = lcctl(inactive);
	if (err) {
		pr_err("Disabling the performance measuring unit "
		       "failed with rc=%x\n", err);
		return;
	}
	cpuhw->flags &= ~PMU_F_ENABLED;
}

/* Number of perf events counting hardware events */
static atomic_t cf_diag_events = ATOMIC_INIT(0);

/* Release the PMU if event is the last perf event */
static void cf_diag_perf_event_destroy(struct perf_event *event)
{
	debug_sprintf_event(cf_diag_dbg, 5,
			    "%s event %p cpu %d cf_diag_events %d\n",
			    __func__, event, event->cpu,
			    atomic_read(&cf_diag_events));
	if (atomic_dec_return(&cf_diag_events) == 0)
		__kernel_cpumcf_end();
}

/* Setup the event. Test for authorized counter sets and only include counter
 * sets which are authorized at the time of the setup. Including unauthorized
 * counter sets result in specification exception (and panic).
 */
static int __hw_perf_event_init(struct perf_event *event)
{
	struct perf_event_attr *attr = &event->attr;
	struct cpu_cf_events *cpuhw;
	enum cpumf_ctr_set i;
	int err = 0;

	debug_sprintf_event(cf_diag_dbg, 5, "%s event %p cpu %d\n", __func__,
			    event, event->cpu);

	event->hw.config = attr->config;
	event->hw.config_base = 0;

	/* Add all authorized counter sets to config_base. The
	 * the hardware init function is either called per-cpu or just once
	 * for all CPUS (event->cpu == -1).  This depends on the whether
	 * counting is started for all CPUs or on a per workload base where
	 * the perf event moves from one CPU to another CPU.
	 * Checking the authorization on any CPU is fine as the hardware
	 * applies the same authorization settings to all CPUs.
	 */
	cpuhw = &get_cpu_var(cpu_cf_events);
	for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i)
		if (cpuhw->info.auth_ctl & cpumf_ctr_ctl[i])
			event->hw.config_base |= cpumf_ctr_ctl[i];
	put_cpu_var(cpu_cf_events);

	/* No authorized counter sets, nothing to count/sample */
	if (!event->hw.config_base) {
		err = -EINVAL;
		goto out;
	}

	/* Set sample_period to indicate sampling */
	event->hw.sample_period = attr->sample_period;
	local64_set(&event->hw.period_left, event->hw.sample_period);
	event->hw.last_period  = event->hw.sample_period;
out:
	debug_sprintf_event(cf_diag_dbg, 5, "%s err %d config_base %#lx\n",
			    __func__, err, event->hw.config_base);
	return err;
}

static int cf_diag_event_init(struct perf_event *event)
{
	struct perf_event_attr *attr = &event->attr;
	int err = -ENOENT;

	debug_sprintf_event(cf_diag_dbg, 5,
			    "%s event %p cpu %d config %#llx "
			    "sample_type %#llx cf_diag_events %d\n", __func__,
			    event, event->cpu, attr->config, attr->sample_type,
			    atomic_read(&cf_diag_events));

	if (event->attr.config != PERF_EVENT_CPUM_CF_DIAG ||
	    event->attr.type != PERF_TYPE_RAW)
		goto out;

	/* Raw events are used to access counters directly,
	 * hence do not permit excludes.
	 * This event is usesless without PERF_SAMPLE_RAW to return counter set
	 * values as raw data.
	 */
	if (attr->exclude_kernel || attr->exclude_user || attr->exclude_hv ||
	    !(attr->sample_type & (PERF_SAMPLE_CPU | PERF_SAMPLE_RAW))) {
		err = -EOPNOTSUPP;
		goto out;
	}

	/* Initialize for using the CPU-measurement counter facility */
	if (atomic_inc_return(&cf_diag_events) == 1) {
		if (__kernel_cpumcf_begin()) {
			atomic_dec(&cf_diag_events);
			err = -EBUSY;
			goto out;
		}
	}
	event->destroy = cf_diag_perf_event_destroy;

	err = __hw_perf_event_init(event);
	if (unlikely(err))
		event->destroy(event);
out:
	debug_sprintf_event(cf_diag_dbg, 5, "%s err %d\n", __func__, err);
	return err;
}

static void cf_diag_read(struct perf_event *event)
{
	debug_sprintf_event(cf_diag_dbg, 5, "%s event %p\n", __func__, event);
}

/* Return the maximum possible counter set size (in number of 8 byte counters)
 * depending on type and model number.
 */
static size_t cf_diag_ctrset_size(enum cpumf_ctr_set ctrset,
				 struct cpumf_ctr_info *info)
{
	size_t ctrset_size = 0;

	switch (ctrset) {
	case CPUMF_CTR_SET_BASIC:
		if (info->cfvn >= 1)
			ctrset_size = 6;
		break;
	case CPUMF_CTR_SET_USER:
		if (info->cfvn == 1)
			ctrset_size = 6;
		else if (info->cfvn >= 3)
			ctrset_size = 2;
		break;
	case CPUMF_CTR_SET_CRYPTO:
		ctrset_size = 16;
		break;
	case CPUMF_CTR_SET_EXT:
		if (info->csvn == 1)
			ctrset_size = 32;
		else if (info->csvn == 2)
			ctrset_size = 48;
		else if (info->csvn >= 3)
			ctrset_size = 128;
		break;
	case CPUMF_CTR_SET_MT_DIAG:
		if (info->csvn > 3)
			ctrset_size = 48;
		break;
	case CPUMF_CTR_SET_MAX:
		break;
	}

	return ctrset_size;
}

/* Calculate memory needed to store all counter sets together with header and
 * trailer data. This is independend of the counter set authorization which
 * can vary depending on the configuration.
 */
static size_t cf_diag_ctrset_maxsize(struct cpumf_ctr_info *info)
{
	size_t max_size = sizeof(struct cf_trailer_entry);
	enum cpumf_ctr_set i;

	for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
		size_t size = cf_diag_ctrset_size(i, info);

		if (size)
			max_size += size * sizeof(u64) +
				    sizeof(struct cf_ctrset_entry);
	}
	debug_sprintf_event(cf_diag_dbg, 5, "%s max_size %zu\n", __func__,
			    max_size);

	return max_size;
}

/* Read a counter set. The counter set number determines which counter set and
 * the CPUM-CF first and second version number determine the number of
 * available counters in this counter set.
 * Each counter set starts with header containing the counter set number and
 * the number of 8 byte counters.
 *
 * The functions returns the number of bytes occupied by this counter set
 * including the header.
 * If there is no counter in the counter set, this counter set is useless and
 * zero is returned on this case.
 */
static size_t cf_diag_getctrset(struct cf_ctrset_entry *ctrdata, int ctrset,
				size_t room)
{
	struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
	size_t ctrset_size, need = 0;
	int rc = 3;				/* Assume write failure */

	ctrdata->def = CF_DIAG_CTRSET_DEF;
	ctrdata->set = ctrset;
	ctrdata->res1 = 0;
	ctrset_size = cf_diag_ctrset_size(ctrset, &cpuhw->info);

	if (ctrset_size) {			/* Save data */
		need = ctrset_size * sizeof(u64) + sizeof(*ctrdata);
		if (need <= room)
			rc = ctr_stcctm(ctrset, ctrset_size,
					(u64 *)(ctrdata + 1));
		if (rc != 3)
			ctrdata->ctr = ctrset_size;
		else
			need = 0;
	}

	debug_sprintf_event(cf_diag_dbg, 6,
			    "%s ctrset %d ctrset_size %zu cfvn %d csvn %d"
			    " need %zd rc:%d\n",
			    __func__, ctrset, ctrset_size, cpuhw->info.cfvn,
			    cpuhw->info.csvn, need, rc);
	return need;
}

/* Read out all counter sets and save them in the provided data buffer.
 * The last 64 byte host an artificial trailer entry.
 */
static size_t cf_diag_getctr(void *data, size_t sz, unsigned long auth)
{
	struct cf_trailer_entry *trailer;
	size_t offset = 0, done;
	int i;

	memset(data, 0, sz);
	sz -= sizeof(*trailer);			/* Always room for trailer */
	for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
		struct cf_ctrset_entry *ctrdata = data + offset;

		if (!(auth & cpumf_ctr_ctl[i]))
			continue;	/* Counter set not authorized */

		done = cf_diag_getctrset(ctrdata, i, sz - offset);
		offset += done;
		debug_sprintf_event(cf_diag_dbg, 6,
				    "%s ctrset %d offset %zu done %zu\n",
				     __func__, i, offset, done);
	}
	trailer = data + offset;
	cf_diag_trailer(trailer);
	return offset + sizeof(*trailer);
}

/* Calculate the difference for each counter in a counter set. */
static void cf_diag_diffctrset(u64 *pstart, u64 *pstop, int counters)
{
	for (; --counters >= 0; ++pstart, ++pstop)
		if (*pstop >= *pstart)
			*pstop -= *pstart;
		else
			*pstop = *pstart - *pstop;
}

/* Scan the counter sets and calculate the difference of each counter
 * in each set. The result is the increment of each counter during the
 * period the counter set has been activated.
 *
 * Return true on success.
 */
static int cf_diag_diffctr(struct cf_diag_csd *csd, unsigned long auth)
{
	struct cf_trailer_entry *trailer_start, *trailer_stop;
	struct cf_ctrset_entry *ctrstart, *ctrstop;
	size_t offset = 0;

	auth &= (1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1;
	do {
		ctrstart = (struct cf_ctrset_entry *)(csd->start + offset);
		ctrstop = (struct cf_ctrset_entry *)(csd->data + offset);

		if (memcmp(ctrstop, ctrstart, sizeof(*ctrstop))) {
			pr_err("cpum_cf_diag counter set compare error "
				"in set %i\n", ctrstart->set);
			return 0;
		}
		auth &= ~cpumf_ctr_ctl[ctrstart->set];
		if (ctrstart->def == CF_DIAG_CTRSET_DEF) {
			cf_diag_diffctrset((u64 *)(ctrstart + 1),
					  (u64 *)(ctrstop + 1), ctrstart->ctr);
			offset += ctrstart->ctr * sizeof(u64) +
				  sizeof(*ctrstart);
		}
		debug_sprintf_event(cf_diag_dbg, 6,
				    "%s set %d ctr %d offset %zu auth %lx\n",
				    __func__, ctrstart->set, ctrstart->ctr,
				    offset, auth);
	} while (ctrstart->def && auth);

	/* Save time_stamp from start of event in stop's trailer */
	trailer_start = (struct cf_trailer_entry *)(csd->start + offset);
	trailer_stop = (struct cf_trailer_entry *)(csd->data + offset);
	trailer_stop->progusage[0] = trailer_start->timestamp;

	return 1;
}

/* Create perf event sample with the counter sets as raw data.	The sample
 * is then pushed to the event subsystem and the function checks for
 * possible event overflows. If an event overflow occurs, the PMU is
 * stopped.
 *
 * Return non-zero if an event overflow occurred.
 */
static int cf_diag_push_sample(struct perf_event *event,
			       struct cf_diag_csd *csd)
{
	struct perf_sample_data data;
	struct perf_raw_record raw;
	struct pt_regs regs;
	int overflow;

	/* Setup perf sample */
	perf_sample_data_init(&data, 0, event->hw.last_period);
	memset(&regs, 0, sizeof(regs));
	memset(&raw, 0, sizeof(raw));

	if (event->attr.sample_type & PERF_SAMPLE_CPU)
		data.cpu_entry.cpu = event->cpu;
	if (event->attr.sample_type & PERF_SAMPLE_RAW) {
		raw.frag.size = csd->used;
		raw.frag.data = csd->data;
		raw.size = csd->used;
		data.raw = &raw;
	}

	overflow = perf_event_overflow(event, &data, &regs);
	debug_sprintf_event(cf_diag_dbg, 6,
			    "%s event %p cpu %d sample_type %#llx raw %d "
			    "ov %d\n", __func__, event, event->cpu,
			    event->attr.sample_type, raw.size, overflow);
	if (overflow)
		event->pmu->stop(event, 0);

	perf_event_update_userpage(event);
	return overflow;
}

static void cf_diag_start(struct perf_event *event, int flags)
{
	struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
	struct cf_diag_csd *csd = this_cpu_ptr(&cf_diag_csd);
	struct hw_perf_event *hwc = &event->hw;

	debug_sprintf_event(cf_diag_dbg, 5,
			    "%s event %p cpu %d flags %#x hwc-state %#x\n",
			    __func__, event, event->cpu, flags, hwc->state);
	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
		return;

	/* (Re-)enable and activate all counter sets */
	lcctl(0);		/* Reset counter sets */
	hwc->state = 0;
	ctr_set_multiple_enable(&cpuhw->state, hwc->config_base);
	lcctl(cpuhw->state);	/* Enable counter sets */
	csd->used = cf_diag_getctr(csd->start, sizeof(csd->start),
				   event->hw.config_base);
	ctr_set_multiple_start(&cpuhw->state, hwc->config_base);
	/* Function cf_diag_enable() starts the counter sets. */
}

static void cf_diag_stop(struct perf_event *event, int flags)
{
	struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
	struct cf_diag_csd *csd = this_cpu_ptr(&cf_diag_csd);
	struct hw_perf_event *hwc = &event->hw;

	debug_sprintf_event(cf_diag_dbg, 5,
			    "%s event %p cpu %d flags %#x hwc-state %#x\n",
			    __func__, event, event->cpu, flags, hwc->state);

	/* Deactivate all counter sets */
	ctr_set_multiple_stop(&cpuhw->state, hwc->config_base);
	local64_inc(&event->count);
	csd->used = cf_diag_getctr(csd->data, sizeof(csd->data),
				   event->hw.config_base);
	if (cf_diag_diffctr(csd, event->hw.config_base))
		cf_diag_push_sample(event, csd);
	hwc->state |= PERF_HES_STOPPED;
}

static int cf_diag_add(struct perf_event *event, int flags)
{
	struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
	int err = 0;

	debug_sprintf_event(cf_diag_dbg, 5,
			    "%s event %p cpu %d flags %#x cpuhw:%p\n",
			    __func__, event, event->cpu, flags, cpuhw);

	if (cpuhw->flags & PMU_F_IN_USE) {
		err = -EAGAIN;
		goto out;
	}

	event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;

	cpuhw->flags |= PMU_F_IN_USE;
	if (flags & PERF_EF_START)
		cf_diag_start(event, PERF_EF_RELOAD);
out:
	debug_sprintf_event(cf_diag_dbg, 5, "%s err %d\n", __func__, err);
	return err;
}

static void cf_diag_del(struct perf_event *event, int flags)
{
	struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);

	debug_sprintf_event(cf_diag_dbg, 5,
			    "%s event %p cpu %d flags %#x\n",
			   __func__, event, event->cpu, flags);

	cf_diag_stop(event, PERF_EF_UPDATE);
	ctr_set_multiple_stop(&cpuhw->state, event->hw.config_base);
	ctr_set_multiple_disable(&cpuhw->state, event->hw.config_base);
	cpuhw->flags &= ~PMU_F_IN_USE;
}

CPUMF_EVENT_ATTR(CF_DIAG, CF_DIAG, PERF_EVENT_CPUM_CF_DIAG);

static struct attribute *cf_diag_events_attr[] = {
	CPUMF_EVENT_PTR(CF_DIAG, CF_DIAG),
	NULL,
};

PMU_FORMAT_ATTR(event, "config:0-63");

static struct attribute *cf_diag_format_attr[] = {
	&format_attr_event.attr,
	NULL,
};

static struct attribute_group cf_diag_events_group = {
	.name = "events",
	.attrs = cf_diag_events_attr,
};
static struct attribute_group cf_diag_format_group = {
	.name = "format",
	.attrs = cf_diag_format_attr,
};
static const struct attribute_group *cf_diag_attr_groups[] = {
	&cf_diag_events_group,
	&cf_diag_format_group,
	NULL,
};

/* Performance monitoring unit for s390x */
static struct pmu cf_diag = {
	.task_ctx_nr  = perf_sw_context,
	.pmu_enable   = cf_diag_enable,
	.pmu_disable  = cf_diag_disable,
	.event_init   = cf_diag_event_init,
	.add	      = cf_diag_add,
	.del	      = cf_diag_del,
	.start	      = cf_diag_start,
	.stop	      = cf_diag_stop,
	.read	      = cf_diag_read,

	.attr_groups  = cf_diag_attr_groups
};

/* Get the CPU speed, try sampling facility first and CPU attributes second. */
static void cf_diag_get_cpu_speed(void)
{
	if (cpum_sf_avail()) {			/* Sampling facility first */
		struct hws_qsi_info_block si;

		memset(&si, 0, sizeof(si));
		if (!qsi(&si)) {
			cf_diag_cpu_speed = si.cpu_speed;
			return;
		}
	}

	if (test_facility(34)) {		/* CPU speed extract static part */
		unsigned long mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);

		if (mhz != -1UL)
			cf_diag_cpu_speed = mhz & 0xffffffff;
	}
}

/* Initialize the counter set PMU to generate complete counter set data as
 * event raw data. This relies on the CPU Measurement Counter Facility device
 * already being loaded and initialized.
 */
static int __init cf_diag_init(void)
{
	struct cpumf_ctr_info info;
	size_t need;
	int rc;

	if (!kernel_cpumcf_avail() || !stccm_avail() || qctri(&info))
		return -ENODEV;
	cf_diag_get_cpu_speed();

	/* Make sure the counter set data fits into predefined buffer. */
	need = cf_diag_ctrset_maxsize(&info);
	if (need > sizeof(((struct cf_diag_csd *)0)->start)) {
		pr_err("Insufficient memory for PMU(cpum_cf_diag) need=%zu\n",
		       need);
		return -ENOMEM;
	}

	/* Setup s390dbf facility */
	cf_diag_dbg = debug_register(KMSG_COMPONENT, 2, 1, 128);
	if (!cf_diag_dbg) {
		pr_err("Registration of s390dbf(cpum_cf_diag) failed\n");
		return -ENOMEM;
	}
	debug_register_view(cf_diag_dbg, &debug_sprintf_view);

	rc = perf_pmu_register(&cf_diag, "cpum_cf_diag", PERF_TYPE_RAW);
	if (rc) {
		debug_unregister_view(cf_diag_dbg, &debug_sprintf_view);
		debug_unregister(cf_diag_dbg);
		pr_err("Registration of PMU(cpum_cf_diag) failed with rc=%i\n",
		       rc);
	}
	return rc;
}
arch_initcall(cf_diag_init);