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  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Performance event support for s390x - CPU-measurement Counter Facility
  4 *
  5 *  Copyright IBM Corp. 2012, 2017
  6 *  Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
  7 */
  8#define KMSG_COMPONENT	"cpum_cf"
  9#define pr_fmt(fmt)	KMSG_COMPONENT ": " fmt
 10
 11#include <linux/kernel.h>
 12#include <linux/kernel_stat.h>
 13#include <linux/perf_event.h>
 14#include <linux/percpu.h>
 15#include <linux/notifier.h>
 16#include <linux/init.h>
 17#include <linux/export.h>
 18#include <asm/ctl_reg.h>
 19#include <asm/irq.h>
 20#include <asm/cpu_mf.h>
 21
 22enum cpumf_ctr_set {
 23	CPUMF_CTR_SET_BASIC   = 0,    /* Basic Counter Set */
 24	CPUMF_CTR_SET_USER    = 1,    /* Problem-State Counter Set */
 25	CPUMF_CTR_SET_CRYPTO  = 2,    /* Crypto-Activity Counter Set */
 26	CPUMF_CTR_SET_EXT     = 3,    /* Extended Counter Set */
 27	CPUMF_CTR_SET_MT_DIAG = 4,    /* MT-diagnostic Counter Set */
 28
 29	/* Maximum number of counter sets */
 30	CPUMF_CTR_SET_MAX,
 31};
 32
 33#define CPUMF_LCCTL_ENABLE_SHIFT    16
 34#define CPUMF_LCCTL_ACTCTL_SHIFT     0
 35static const u64 cpumf_state_ctl[CPUMF_CTR_SET_MAX] = {
 36	[CPUMF_CTR_SET_BASIC]	= 0x02,
 37	[CPUMF_CTR_SET_USER]	= 0x04,
 38	[CPUMF_CTR_SET_CRYPTO]	= 0x08,
 39	[CPUMF_CTR_SET_EXT]	= 0x01,
 40	[CPUMF_CTR_SET_MT_DIAG] = 0x20,
 41};
 42
 43static void ctr_set_enable(u64 *state, int ctr_set)
 44{
 45	*state |= cpumf_state_ctl[ctr_set] << CPUMF_LCCTL_ENABLE_SHIFT;
 46}
 47static void ctr_set_disable(u64 *state, int ctr_set)
 48{
 49	*state &= ~(cpumf_state_ctl[ctr_set] << CPUMF_LCCTL_ENABLE_SHIFT);
 50}
 51static void ctr_set_start(u64 *state, int ctr_set)
 52{
 53	*state |= cpumf_state_ctl[ctr_set] << CPUMF_LCCTL_ACTCTL_SHIFT;
 54}
 55static void ctr_set_stop(u64 *state, int ctr_set)
 56{
 57	*state &= ~(cpumf_state_ctl[ctr_set] << CPUMF_LCCTL_ACTCTL_SHIFT);
 58}
 59
 60/* Local CPUMF event structure */
 61struct cpu_hw_events {
 62	struct cpumf_ctr_info	info;
 63	atomic_t		ctr_set[CPUMF_CTR_SET_MAX];
 64	u64			state, tx_state;
 65	unsigned int		flags;
 66	unsigned int		txn_flags;
 67};
 68static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
 69	.ctr_set = {
 70		[CPUMF_CTR_SET_BASIC]	= ATOMIC_INIT(0),
 71		[CPUMF_CTR_SET_USER]	= ATOMIC_INIT(0),
 72		[CPUMF_CTR_SET_CRYPTO]	= ATOMIC_INIT(0),
 73		[CPUMF_CTR_SET_EXT]	= ATOMIC_INIT(0),
 74		[CPUMF_CTR_SET_MT_DIAG] = ATOMIC_INIT(0),
 75	},
 76	.state = 0,
 77	.flags = 0,
 78	.txn_flags = 0,
 79};
 80
 81static enum cpumf_ctr_set get_counter_set(u64 event)
 82{
 83	int set = CPUMF_CTR_SET_MAX;
 84
 85	if (event < 32)
 86		set = CPUMF_CTR_SET_BASIC;
 87	else if (event < 64)
 88		set = CPUMF_CTR_SET_USER;
 89	else if (event < 128)
 90		set = CPUMF_CTR_SET_CRYPTO;
 91	else if (event < 256)
 92		set = CPUMF_CTR_SET_EXT;
 93	else if (event >= 448 && event < 496)
 94		set = CPUMF_CTR_SET_MT_DIAG;
 95
 96	return set;
 97}
 98
 99static int validate_ctr_version(const struct hw_perf_event *hwc)
100{
101	struct cpu_hw_events *cpuhw;
102	int err = 0;
103	u16 mtdiag_ctl;
104
105	cpuhw = &get_cpu_var(cpu_hw_events);
106
107	/* check required version for counter sets */
108	switch (hwc->config_base) {
109	case CPUMF_CTR_SET_BASIC:
110	case CPUMF_CTR_SET_USER:
111		if (cpuhw->info.cfvn < 1)
112			err = -EOPNOTSUPP;
113		break;
114	case CPUMF_CTR_SET_CRYPTO:
115	case CPUMF_CTR_SET_EXT:
116		if (cpuhw->info.csvn < 1)
117			err = -EOPNOTSUPP;
118		if ((cpuhw->info.csvn == 1 && hwc->config > 159) ||
119		    (cpuhw->info.csvn == 2 && hwc->config > 175) ||
120		    (cpuhw->info.csvn  > 2 && hwc->config > 255))
121			err = -EOPNOTSUPP;
122		break;
123	case CPUMF_CTR_SET_MT_DIAG:
124		if (cpuhw->info.csvn <= 3)
125			err = -EOPNOTSUPP;
126		/*
127		 * MT-diagnostic counters are read-only.  The counter set
128		 * is automatically enabled and activated on all CPUs with
129		 * multithreading (SMT).  Deactivation of multithreading
130		 * also disables the counter set.  State changes are ignored
131		 * by lcctl().	Because Linux controls SMT enablement through
132		 * a kernel parameter only, the counter set is either disabled
133		 * or enabled and active.
134		 *
135		 * Thus, the counters can only be used if SMT is on and the
136		 * counter set is enabled and active.
137		 */
138		mtdiag_ctl = cpumf_state_ctl[CPUMF_CTR_SET_MT_DIAG];
139		if (!((cpuhw->info.auth_ctl & mtdiag_ctl) &&
140		      (cpuhw->info.enable_ctl & mtdiag_ctl) &&
141		      (cpuhw->info.act_ctl & mtdiag_ctl)))
142			err = -EOPNOTSUPP;
143		break;
144	}
145
146	put_cpu_var(cpu_hw_events);
147	return err;
148}
149
150static int validate_ctr_auth(const struct hw_perf_event *hwc)
151{
152	struct cpu_hw_events *cpuhw;
153	u64 ctrs_state;
154	int err = 0;
155
156	cpuhw = &get_cpu_var(cpu_hw_events);
157
158	/* Check authorization for cpu counter sets.
159	 * If the particular CPU counter set is not authorized,
160	 * return with -ENOENT in order to fall back to other
161	 * PMUs that might suffice the event request.
162	 */
163	ctrs_state = cpumf_state_ctl[hwc->config_base];
164	if (!(ctrs_state & cpuhw->info.auth_ctl))
165		err = -ENOENT;
166
167	put_cpu_var(cpu_hw_events);
168	return err;
169}
170
171/*
172 * Change the CPUMF state to active.
173 * Enable and activate the CPU-counter sets according
174 * to the per-cpu control state.
175 */
176static void cpumf_pmu_enable(struct pmu *pmu)
177{
178	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
179	int err;
180
181	if (cpuhw->flags & PMU_F_ENABLED)
182		return;
183
184	err = lcctl(cpuhw->state);
185	if (err) {
186		pr_err("Enabling the performance measuring unit "
187		       "failed with rc=%x\n", err);
188		return;
189	}
190
191	cpuhw->flags |= PMU_F_ENABLED;
192}
193
194/*
195 * Change the CPUMF state to inactive.
196 * Disable and enable (inactive) the CPU-counter sets according
197 * to the per-cpu control state.
198 */
199static void cpumf_pmu_disable(struct pmu *pmu)
200{
201	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
202	int err;
203	u64 inactive;
204
205	if (!(cpuhw->flags & PMU_F_ENABLED))
206		return;
207
208	inactive = cpuhw->state & ~((1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1);
209	err = lcctl(inactive);
210	if (err) {
211		pr_err("Disabling the performance measuring unit "
212		       "failed with rc=%x\n", err);
213		return;
214	}
215
216	cpuhw->flags &= ~PMU_F_ENABLED;
217}
218
219
220/* Number of perf events counting hardware events */
221static atomic_t num_events = ATOMIC_INIT(0);
222/* Used to avoid races in calling reserve/release_cpumf_hardware */
223static DEFINE_MUTEX(pmc_reserve_mutex);
224
225/* CPU-measurement alerts for the counter facility */
226static void cpumf_measurement_alert(struct ext_code ext_code,
227				    unsigned int alert, unsigned long unused)
228{
229	struct cpu_hw_events *cpuhw;
230
231	if (!(alert & CPU_MF_INT_CF_MASK))
232		return;
233
234	inc_irq_stat(IRQEXT_CMC);
235	cpuhw = this_cpu_ptr(&cpu_hw_events);
236
237	/* Measurement alerts are shared and might happen when the PMU
238	 * is not reserved.  Ignore these alerts in this case. */
239	if (!(cpuhw->flags & PMU_F_RESERVED))
240		return;
241
242	/* counter authorization change alert */
243	if (alert & CPU_MF_INT_CF_CACA)
244		qctri(&cpuhw->info);
245
246	/* loss of counter data alert */
247	if (alert & CPU_MF_INT_CF_LCDA)
248		pr_err("CPU[%i] Counter data was lost\n", smp_processor_id());
249
250	/* loss of MT counter data alert */
251	if (alert & CPU_MF_INT_CF_MTDA)
252		pr_warn("CPU[%i] MT counter data was lost\n",
253			smp_processor_id());
254}
255
256#define PMC_INIT      0
257#define PMC_RELEASE   1
258static void setup_pmc_cpu(void *flags)
259{
260	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
261
262	switch (*((int *) flags)) {
263	case PMC_INIT:
264		memset(&cpuhw->info, 0, sizeof(cpuhw->info));
265		qctri(&cpuhw->info);
266		cpuhw->flags |= PMU_F_RESERVED;
267		break;
268
269	case PMC_RELEASE:
270		cpuhw->flags &= ~PMU_F_RESERVED;
271		break;
272	}
273
274	/* Disable CPU counter sets */
275	lcctl(0);
276}
277
278/* Initialize the CPU-measurement facility */
279static int reserve_pmc_hardware(void)
280{
281	int flags = PMC_INIT;
282
283	on_each_cpu(setup_pmc_cpu, &flags, 1);
284	irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT);
285
286	return 0;
287}
288
289/* Release the CPU-measurement facility */
290static void release_pmc_hardware(void)
291{
292	int flags = PMC_RELEASE;
293
294	on_each_cpu(setup_pmc_cpu, &flags, 1);
295	irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT);
296}
297
298/* Release the PMU if event is the last perf event */
299static void hw_perf_event_destroy(struct perf_event *event)
300{
301	if (!atomic_add_unless(&num_events, -1, 1)) {
302		mutex_lock(&pmc_reserve_mutex);
303		if (atomic_dec_return(&num_events) == 0)
304			release_pmc_hardware();
305		mutex_unlock(&pmc_reserve_mutex);
306	}
307}
308
309/* CPUMF <-> perf event mappings for kernel+userspace (basic set) */
310static const int cpumf_generic_events_basic[] = {
311	[PERF_COUNT_HW_CPU_CYCLES]	    = 0,
312	[PERF_COUNT_HW_INSTRUCTIONS]	    = 1,
313	[PERF_COUNT_HW_CACHE_REFERENCES]    = -1,
314	[PERF_COUNT_HW_CACHE_MISSES]	    = -1,
315	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = -1,
316	[PERF_COUNT_HW_BRANCH_MISSES]	    = -1,
317	[PERF_COUNT_HW_BUS_CYCLES]	    = -1,
318};
319/* CPUMF <-> perf event mappings for userspace (problem-state set) */
320static const int cpumf_generic_events_user[] = {
321	[PERF_COUNT_HW_CPU_CYCLES]	    = 32,
322	[PERF_COUNT_HW_INSTRUCTIONS]	    = 33,
323	[PERF_COUNT_HW_CACHE_REFERENCES]    = -1,
324	[PERF_COUNT_HW_CACHE_MISSES]	    = -1,
325	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = -1,
326	[PERF_COUNT_HW_BRANCH_MISSES]	    = -1,
327	[PERF_COUNT_HW_BUS_CYCLES]	    = -1,
328};
329
330static int __hw_perf_event_init(struct perf_event *event)
331{
332	struct perf_event_attr *attr = &event->attr;
333	struct hw_perf_event *hwc = &event->hw;
334	enum cpumf_ctr_set set;
335	int err;
336	u64 ev;
337
338	switch (attr->type) {
339	case PERF_TYPE_RAW:
340		/* Raw events are used to access counters directly,
341		 * hence do not permit excludes */
342		if (attr->exclude_kernel || attr->exclude_user ||
343		    attr->exclude_hv)
344			return -EOPNOTSUPP;
345		ev = attr->config;
346		break;
347
348	case PERF_TYPE_HARDWARE:
349		ev = attr->config;
350		/* Count user space (problem-state) only */
351		if (!attr->exclude_user && attr->exclude_kernel) {
352			if (ev >= ARRAY_SIZE(cpumf_generic_events_user))
353				return -EOPNOTSUPP;
354			ev = cpumf_generic_events_user[ev];
355
356		/* No support for kernel space counters only */
357		} else if (!attr->exclude_kernel && attr->exclude_user) {
358			return -EOPNOTSUPP;
359
360		/* Count user and kernel space */
361		} else {
362			if (ev >= ARRAY_SIZE(cpumf_generic_events_basic))
363				return -EOPNOTSUPP;
364			ev = cpumf_generic_events_basic[ev];
365		}
366		break;
367
368	default:
369		return -ENOENT;
370	}
371
372	if (ev == -1)
373		return -ENOENT;
374
375	if (ev > PERF_CPUM_CF_MAX_CTR)
376		return -EINVAL;
377
378	/* Obtain the counter set to which the specified counter belongs */
379	set = get_counter_set(ev);
380	switch (set) {
381	case CPUMF_CTR_SET_BASIC:
382	case CPUMF_CTR_SET_USER:
383	case CPUMF_CTR_SET_CRYPTO:
384	case CPUMF_CTR_SET_EXT:
385	case CPUMF_CTR_SET_MT_DIAG:
386		/*
387		 * Use the hardware perf event structure to store the
388		 * counter number in the 'config' member and the counter
389		 * set number in the 'config_base'.  The counter set number
390		 * is then later used to enable/disable the counter(s).
391		 */
392		hwc->config = ev;
393		hwc->config_base = set;
394		break;
395	case CPUMF_CTR_SET_MAX:
396		/* The counter could not be associated to a counter set */
397		return -EINVAL;
398	};
399
400	/* Initialize for using the CPU-measurement counter facility */
401	if (!atomic_inc_not_zero(&num_events)) {
402		mutex_lock(&pmc_reserve_mutex);
403		if (atomic_read(&num_events) == 0 && reserve_pmc_hardware())
404			err = -EBUSY;
405		else
406			atomic_inc(&num_events);
407		mutex_unlock(&pmc_reserve_mutex);
408	}
409	event->destroy = hw_perf_event_destroy;
410
411	/* Finally, validate version and authorization of the counter set */
412	err = validate_ctr_auth(hwc);
413	if (!err)
414		err = validate_ctr_version(hwc);
415
416	return err;
417}
418
419static int cpumf_pmu_event_init(struct perf_event *event)
420{
421	int err;
422
423	switch (event->attr.type) {
424	case PERF_TYPE_HARDWARE:
425	case PERF_TYPE_HW_CACHE:
426	case PERF_TYPE_RAW:
427		err = __hw_perf_event_init(event);
428		break;
429	default:
430		return -ENOENT;
431	}
432
433	if (unlikely(err) && event->destroy)
434		event->destroy(event);
435
436	return err;
437}
438
439static int hw_perf_event_reset(struct perf_event *event)
440{
441	u64 prev, new;
442	int err;
443
444	do {
445		prev = local64_read(&event->hw.prev_count);
446		err = ecctr(event->hw.config, &new);
447		if (err) {
448			if (err != 3)
449				break;
450			/* The counter is not (yet) available. This
451			 * might happen if the counter set to which
452			 * this counter belongs is in the disabled
453			 * state.
454			 */
455			new = 0;
456		}
457	} while (local64_cmpxchg(&event->hw.prev_count, prev, new) != prev);
458
459	return err;
460}
461
462static void hw_perf_event_update(struct perf_event *event)
463{
464	u64 prev, new, delta;
465	int err;
466
467	do {
468		prev = local64_read(&event->hw.prev_count);
469		err = ecctr(event->hw.config, &new);
470		if (err)
471			return;
472	} while (local64_cmpxchg(&event->hw.prev_count, prev, new) != prev);
473
474	delta = (prev <= new) ? new - prev
475			      : (-1ULL - prev) + new + 1;	 /* overflow */
476	local64_add(delta, &event->count);
477}
478
479static void cpumf_pmu_read(struct perf_event *event)
480{
481	if (event->hw.state & PERF_HES_STOPPED)
482		return;
483
484	hw_perf_event_update(event);
485}
486
487static void cpumf_pmu_start(struct perf_event *event, int flags)
488{
489	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
490	struct hw_perf_event *hwc = &event->hw;
491
492	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
493		return;
494
495	if (WARN_ON_ONCE(hwc->config == -1))
496		return;
497
498	if (flags & PERF_EF_RELOAD)
499		WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
500
501	hwc->state = 0;
502
503	/* (Re-)enable and activate the counter set */
504	ctr_set_enable(&cpuhw->state, hwc->config_base);
505	ctr_set_start(&cpuhw->state, hwc->config_base);
506
507	/* The counter set to which this counter belongs can be already active.
508	 * Because all counters in a set are active, the event->hw.prev_count
509	 * needs to be synchronized.  At this point, the counter set can be in
510	 * the inactive or disabled state.
511	 */
512	hw_perf_event_reset(event);
513
514	/* increment refcount for this counter set */
515	atomic_inc(&cpuhw->ctr_set[hwc->config_base]);
516}
517
518static void cpumf_pmu_stop(struct perf_event *event, int flags)
519{
520	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
521	struct hw_perf_event *hwc = &event->hw;
522
523	if (!(hwc->state & PERF_HES_STOPPED)) {
524		/* Decrement reference count for this counter set and if this
525		 * is the last used counter in the set, clear activation
526		 * control and set the counter set state to inactive.
527		 */
528		if (!atomic_dec_return(&cpuhw->ctr_set[hwc->config_base]))
529			ctr_set_stop(&cpuhw->state, hwc->config_base);
530		event->hw.state |= PERF_HES_STOPPED;
531	}
532
533	if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
534		hw_perf_event_update(event);
535		event->hw.state |= PERF_HES_UPTODATE;
536	}
537}
538
539static int cpumf_pmu_add(struct perf_event *event, int flags)
540{
541	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
542
543	/* Check authorization for the counter set to which this
544	 * counter belongs.
545	 * For group events transaction, the authorization check is
546	 * done in cpumf_pmu_commit_txn().
547	 */
548	if (!(cpuhw->txn_flags & PERF_PMU_TXN_ADD))
549		if (validate_ctr_auth(&event->hw))
550			return -ENOENT;
551
552	ctr_set_enable(&cpuhw->state, event->hw.config_base);
553	event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
554
555	if (flags & PERF_EF_START)
556		cpumf_pmu_start(event, PERF_EF_RELOAD);
557
558	perf_event_update_userpage(event);
559
560	return 0;
561}
562
563static void cpumf_pmu_del(struct perf_event *event, int flags)
564{
565	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
566
567	cpumf_pmu_stop(event, PERF_EF_UPDATE);
568
569	/* Check if any counter in the counter set is still used.  If not used,
570	 * change the counter set to the disabled state.  This also clears the
571	 * content of all counters in the set.
572	 *
573	 * When a new perf event has been added but not yet started, this can
574	 * clear enable control and resets all counters in a set.  Therefore,
575	 * cpumf_pmu_start() always has to reenable a counter set.
576	 */
577	if (!atomic_read(&cpuhw->ctr_set[event->hw.config_base]))
578		ctr_set_disable(&cpuhw->state, event->hw.config_base);
579
580	perf_event_update_userpage(event);
581}
582
583/*
584 * Start group events scheduling transaction.
585 * Set flags to perform a single test at commit time.
586 *
587 * We only support PERF_PMU_TXN_ADD transactions. Save the
588 * transaction flags but otherwise ignore non-PERF_PMU_TXN_ADD
589 * transactions.
590 */
591static void cpumf_pmu_start_txn(struct pmu *pmu, unsigned int txn_flags)
592{
593	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
594
595	WARN_ON_ONCE(cpuhw->txn_flags);		/* txn already in flight */
596
597	cpuhw->txn_flags = txn_flags;
598	if (txn_flags & ~PERF_PMU_TXN_ADD)
599		return;
600
601	perf_pmu_disable(pmu);
602	cpuhw->tx_state = cpuhw->state;
603}
604
605/*
606 * Stop and cancel a group events scheduling tranctions.
607 * Assumes cpumf_pmu_del() is called for each successful added
608 * cpumf_pmu_add() during the transaction.
609 */
610static void cpumf_pmu_cancel_txn(struct pmu *pmu)
611{
612	unsigned int txn_flags;
613	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
614
615	WARN_ON_ONCE(!cpuhw->txn_flags);	/* no txn in flight */
616
617	txn_flags = cpuhw->txn_flags;
618	cpuhw->txn_flags = 0;
619	if (txn_flags & ~PERF_PMU_TXN_ADD)
620		return;
621
622	WARN_ON(cpuhw->tx_state != cpuhw->state);
623
624	perf_pmu_enable(pmu);
625}
626
627/*
628 * Commit the group events scheduling transaction.  On success, the
629 * transaction is closed.   On error, the transaction is kept open
630 * until cpumf_pmu_cancel_txn() is called.
631 */
632static int cpumf_pmu_commit_txn(struct pmu *pmu)
633{
634	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
635	u64 state;
636
637	WARN_ON_ONCE(!cpuhw->txn_flags);	/* no txn in flight */
638
639	if (cpuhw->txn_flags & ~PERF_PMU_TXN_ADD) {
640		cpuhw->txn_flags = 0;
641		return 0;
642	}
643
644	/* check if the updated state can be scheduled */
645	state = cpuhw->state & ~((1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1);
646	state >>= CPUMF_LCCTL_ENABLE_SHIFT;
647	if ((state & cpuhw->info.auth_ctl) != state)
648		return -ENOENT;
649
650	cpuhw->txn_flags = 0;
651	perf_pmu_enable(pmu);
652	return 0;
653}
654
655/* Performance monitoring unit for s390x */
656static struct pmu cpumf_pmu = {
657	.task_ctx_nr  = perf_sw_context,
658	.capabilities = PERF_PMU_CAP_NO_INTERRUPT,
659	.pmu_enable   = cpumf_pmu_enable,
660	.pmu_disable  = cpumf_pmu_disable,
661	.event_init   = cpumf_pmu_event_init,
662	.add	      = cpumf_pmu_add,
663	.del	      = cpumf_pmu_del,
664	.start	      = cpumf_pmu_start,
665	.stop	      = cpumf_pmu_stop,
666	.read	      = cpumf_pmu_read,
667	.start_txn    = cpumf_pmu_start_txn,
668	.commit_txn   = cpumf_pmu_commit_txn,
669	.cancel_txn   = cpumf_pmu_cancel_txn,
670};
671
672static int cpumf_pmf_setup(unsigned int cpu, int flags)
673{
674	local_irq_disable();
675	setup_pmc_cpu(&flags);
676	local_irq_enable();
677	return 0;
678}
679
680static int s390_pmu_online_cpu(unsigned int cpu)
681{
682	return cpumf_pmf_setup(cpu, PMC_INIT);
683}
684
685static int s390_pmu_offline_cpu(unsigned int cpu)
686{
687	return cpumf_pmf_setup(cpu, PMC_RELEASE);
688}
689
690static int __init cpumf_pmu_init(void)
691{
692	int rc;
693
694	if (!cpum_cf_avail())
695		return -ENODEV;
696
697	/* clear bit 15 of cr0 to unauthorize problem-state to
698	 * extract measurement counters */
699	ctl_clear_bit(0, 48);
700
701	/* register handler for measurement-alert interruptions */
702	rc = register_external_irq(EXT_IRQ_MEASURE_ALERT,
703				   cpumf_measurement_alert);
704	if (rc) {
705		pr_err("Registering for CPU-measurement alerts "
706		       "failed with rc=%i\n", rc);
707		return rc;
708	}
709
710	cpumf_pmu.attr_groups = cpumf_cf_event_group();
711	rc = perf_pmu_register(&cpumf_pmu, "cpum_cf", PERF_TYPE_RAW);
712	if (rc) {
713		pr_err("Registering the cpum_cf PMU failed with rc=%i\n", rc);
714		unregister_external_irq(EXT_IRQ_MEASURE_ALERT,
715					cpumf_measurement_alert);
716		return rc;
717	}
718	return cpuhp_setup_state(CPUHP_AP_PERF_S390_CF_ONLINE,
719				 "perf/s390/cf:online",
720				 s390_pmu_online_cpu, s390_pmu_offline_cpu);
721}
722early_initcall(cpumf_pmu_init);