perf_cpum_cf.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Performance event support for s390x - CPU-measurement Counter Facility
   4 *
   5 *  Copyright IBM Corp. 2012, 2023
   6 *  Author(s): Hendrik Brueckner <brueckner@linux.ibm.com>
   7 *	       Thomas Richter <tmricht@linux.ibm.com>
   8 */
   9#define pr_fmt(fmt) "cpum_cf: " fmt
  10
  11#include <linux/kernel.h>
  12#include <linux/kernel_stat.h>
  13#include <linux/percpu.h>
  14#include <linux/notifier.h>
  15#include <linux/init.h>
  16#include <linux/miscdevice.h>
  17#include <linux/perf_event.h>
  18
  19#include <asm/cpu_mf.h>
  20#include <asm/hwctrset.h>
  21#include <asm/debug.h>
  22
  23/* Perf PMU definitions for the counter facility */
  24#define PERF_CPUM_CF_MAX_CTR		0xffffUL  /* Max ctr for ECCTR */
  25#define PERF_EVENT_CPUM_CF_DIAG		0xBC000UL /* Event: Counter sets */
  26
  27enum cpumf_ctr_set {
  28	CPUMF_CTR_SET_BASIC   = 0,    /* Basic Counter Set */
  29	CPUMF_CTR_SET_USER    = 1,    /* Problem-State Counter Set */
  30	CPUMF_CTR_SET_CRYPTO  = 2,    /* Crypto-Activity Counter Set */
  31	CPUMF_CTR_SET_EXT     = 3,    /* Extended Counter Set */
  32	CPUMF_CTR_SET_MT_DIAG = 4,    /* MT-diagnostic Counter Set */
  33
  34	/* Maximum number of counter sets */
  35	CPUMF_CTR_SET_MAX,
  36};
  37
  38#define CPUMF_LCCTL_ENABLE_SHIFT    16
  39#define CPUMF_LCCTL_ACTCTL_SHIFT     0
  40
  41static inline void ctr_set_enable(u64 *state, u64 ctrsets)
  42{
  43	*state |= ctrsets << CPUMF_LCCTL_ENABLE_SHIFT;
  44}
  45
  46static inline void ctr_set_disable(u64 *state, u64 ctrsets)
  47{
  48	*state &= ~(ctrsets << CPUMF_LCCTL_ENABLE_SHIFT);
  49}
  50
  51static inline void ctr_set_start(u64 *state, u64 ctrsets)
  52{
  53	*state |= ctrsets << CPUMF_LCCTL_ACTCTL_SHIFT;
  54}
  55
  56static inline void ctr_set_stop(u64 *state, u64 ctrsets)
  57{
  58	*state &= ~(ctrsets << CPUMF_LCCTL_ACTCTL_SHIFT);
  59}
  60
  61static inline int ctr_stcctm(enum cpumf_ctr_set set, u64 range, u64 *dest)
  62{
  63	switch (set) {
  64	case CPUMF_CTR_SET_BASIC:
  65		return stcctm(BASIC, range, dest);
  66	case CPUMF_CTR_SET_USER:
  67		return stcctm(PROBLEM_STATE, range, dest);
  68	case CPUMF_CTR_SET_CRYPTO:
  69		return stcctm(CRYPTO_ACTIVITY, range, dest);
  70	case CPUMF_CTR_SET_EXT:
  71		return stcctm(EXTENDED, range, dest);
  72	case CPUMF_CTR_SET_MT_DIAG:
  73		return stcctm(MT_DIAG_CLEARING, range, dest);
  74	case CPUMF_CTR_SET_MAX:
  75		return 3;
  76	}
  77	return 3;
  78}
  79
  80struct cpu_cf_events {
  81	refcount_t refcnt;		/* Reference count */
  82	atomic_t		ctr_set[CPUMF_CTR_SET_MAX];
  83	u64			state;		/* For perf_event_open SVC */
  84	u64			dev_state;	/* For /dev/hwctr */
  85	unsigned int		flags;
  86	size_t used;			/* Bytes used in data */
  87	size_t usedss;			/* Bytes used in start/stop */
  88	unsigned char start[PAGE_SIZE];	/* Counter set at event add */
  89	unsigned char stop[PAGE_SIZE];	/* Counter set at event delete */
  90	unsigned char data[PAGE_SIZE];	/* Counter set at /dev/hwctr */
  91	unsigned int sets;		/* # Counter set saved in memory */
  92};
  93
  94static unsigned int cfdiag_cpu_speed;	/* CPU speed for CF_DIAG trailer */
  95static debug_info_t *cf_dbg;
  96
  97/*
  98 * The CPU Measurement query counter information instruction contains
  99 * information which varies per machine generation, but is constant and
 100 * does not change when running on a particular machine, such as counter
 101 * first and second version number. This is needed to determine the size
 102 * of counter sets. Extract this information at device driver initialization.
 103 */
 104static struct cpumf_ctr_info	cpumf_ctr_info;
 105
 106struct cpu_cf_ptr {
 107	struct cpu_cf_events *cpucf;
 108};
 109
 110static struct cpu_cf_root {		/* Anchor to per CPU data */
 111	refcount_t refcnt;		/* Overall active events */
 112	struct cpu_cf_ptr __percpu *cfptr;
 113} cpu_cf_root;
 114
 115/*
 116 * Serialize event initialization and event removal. Both are called from
 117 * user space in task context with perf_event_open() and close()
 118 * system calls.
 119 *
 120 * This mutex serializes functions cpum_cf_alloc_cpu() called at event
 121 * initialization via cpumf_pmu_event_init() and function cpum_cf_free_cpu()
 122 * called at event removal via call back function hw_perf_event_destroy()
 123 * when the event is deleted. They are serialized to enforce correct
 124 * bookkeeping of pointer and reference counts anchored by
 125 * struct cpu_cf_root and the access to cpu_cf_root::refcnt and the
 126 * per CPU pointers stored in cpu_cf_root::cfptr.
 127 */
 128static DEFINE_MUTEX(pmc_reserve_mutex);
 129
 130/*
 131 * Get pointer to per-cpu structure.
 132 *
 133 * Function get_cpu_cfhw() is called from
 134 * - cfset_copy_all(): This function is protected by cpus_read_lock(), so
 135 *   CPU hot plug remove can not happen. Event removal requires a close()
 136 *   first.
 137 *
 138 * Function this_cpu_cfhw() is called from perf common code functions:
 139 * - pmu_{en|dis}able(), pmu_{add|del}()and pmu_{start|stop}():
 140 *   All functions execute with interrupts disabled on that particular CPU.
 141 * - cfset_ioctl_{on|off}, cfset_cpu_read(): see comment cfset_copy_all().
 142 *
 143 * Therefore it is safe to access the CPU specific pointer to the event.
 144 */
 145static struct cpu_cf_events *get_cpu_cfhw(int cpu)
 146{
 147	struct cpu_cf_ptr __percpu *p = cpu_cf_root.cfptr;
 148
 149	if (p) {
 150		struct cpu_cf_ptr *q = per_cpu_ptr(p, cpu);
 151
 152		return q->cpucf;
 153	}
 154	return NULL;
 155}
 156
 157static struct cpu_cf_events *this_cpu_cfhw(void)
 158{
 159	return get_cpu_cfhw(smp_processor_id());
 160}
 161
 162/* Disable counter sets on dedicated CPU */
 163static void cpum_cf_reset_cpu(void *flags)
 164{
 165	lcctl(0);
 166}
 167
 168/* Free per CPU data when the last event is removed. */
 169static void cpum_cf_free_root(void)
 170{
 171	if (!refcount_dec_and_test(&cpu_cf_root.refcnt))
 172		return;
 173	free_percpu(cpu_cf_root.cfptr);
 174	cpu_cf_root.cfptr = NULL;
 175	irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT);
 176	on_each_cpu(cpum_cf_reset_cpu, NULL, 1);
 177	debug_sprintf_event(cf_dbg, 4, "%s root.refcnt %u cfptr %d\n",
 178			    __func__, refcount_read(&cpu_cf_root.refcnt),
 179			    !cpu_cf_root.cfptr);
 180}
 181
 182/*
 183 * On initialization of first event also allocate per CPU data dynamically.
 184 * Start with an array of pointers, the array size is the maximum number of
 185 * CPUs possible, which might be larger than the number of CPUs currently
 186 * online.
 187 */
 188static int cpum_cf_alloc_root(void)
 189{
 190	int rc = 0;
 191
 192	if (refcount_inc_not_zero(&cpu_cf_root.refcnt))
 193		return rc;
 194
 195	/* The memory is already zeroed. */
 196	cpu_cf_root.cfptr = alloc_percpu(struct cpu_cf_ptr);
 197	if (cpu_cf_root.cfptr) {
 198		refcount_set(&cpu_cf_root.refcnt, 1);
 199		on_each_cpu(cpum_cf_reset_cpu, NULL, 1);
 200		irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT);
 201	} else {
 202		rc = -ENOMEM;
 203	}
 204
 205	return rc;
 206}
 207
 208/* Free CPU counter data structure for a PMU */
 209static void cpum_cf_free_cpu(int cpu)
 210{
 211	struct cpu_cf_events *cpuhw;
 212	struct cpu_cf_ptr *p;
 213
 214	mutex_lock(&pmc_reserve_mutex);
 215	/*
 216	 * When invoked via CPU hotplug handler, there might be no events
 217	 * installed or that particular CPU might not have an
 218	 * event installed. This anchor pointer can be NULL!
 219	 */
 220	if (!cpu_cf_root.cfptr)
 221		goto out;
 222	p = per_cpu_ptr(cpu_cf_root.cfptr, cpu);
 223	cpuhw = p->cpucf;
 224	/*
 225	 * Might be zero when called from CPU hotplug handler and no event
 226	 * installed on that CPU, but on different CPUs.
 227	 */
 228	if (!cpuhw)
 229		goto out;
 230
 231	if (refcount_dec_and_test(&cpuhw->refcnt)) {
 232		kfree(cpuhw);
 233		p->cpucf = NULL;
 234	}
 235	cpum_cf_free_root();
 236out:
 237	mutex_unlock(&pmc_reserve_mutex);
 238}
 239
 240/* Allocate CPU counter data structure for a PMU. Called under mutex lock. */
 241static int cpum_cf_alloc_cpu(int cpu)
 242{
 243	struct cpu_cf_events *cpuhw;
 244	struct cpu_cf_ptr *p;
 245	int rc;
 246
 247	mutex_lock(&pmc_reserve_mutex);
 248	rc = cpum_cf_alloc_root();
 249	if (rc)
 250		goto unlock;
 251	p = per_cpu_ptr(cpu_cf_root.cfptr, cpu);
 252	cpuhw = p->cpucf;
 253
 254	if (!cpuhw) {
 255		cpuhw = kzalloc(sizeof(*cpuhw), GFP_KERNEL);
 256		if (cpuhw) {
 257			p->cpucf = cpuhw;
 258			refcount_set(&cpuhw->refcnt, 1);
 259		} else {
 260			rc = -ENOMEM;
 261		}
 262	} else {
 263		refcount_inc(&cpuhw->refcnt);
 264	}
 265	if (rc) {
 266		/*
 267		 * Error in allocation of event, decrement anchor. Since
 268		 * cpu_cf_event in not created, its destroy() function is not
 269		 * invoked. Adjust the reference counter for the anchor.
 270		 */
 271		cpum_cf_free_root();
 272	}
 273unlock:
 274	mutex_unlock(&pmc_reserve_mutex);
 275	return rc;
 276}
 277
 278/*
 279 * Create/delete per CPU data structures for /dev/hwctr interface and events
 280 * created by perf_event_open().
 281 * If cpu is -1, track task on all available CPUs. This requires
 282 * allocation of hardware data structures for all CPUs. This setup handles
 283 * perf_event_open() with task context and /dev/hwctr interface.
 284 * If cpu is non-zero install event on this CPU only. This setup handles
 285 * perf_event_open() with CPU context.
 286 */
 287static int cpum_cf_alloc(int cpu)
 288{
 289	cpumask_var_t mask;
 290	int rc;
 291
 292	if (cpu == -1) {
 293		if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
 294			return -ENOMEM;
 295		for_each_online_cpu(cpu) {
 296			rc = cpum_cf_alloc_cpu(cpu);
 297			if (rc) {
 298				for_each_cpu(cpu, mask)
 299					cpum_cf_free_cpu(cpu);
 300				break;
 301			}
 302			cpumask_set_cpu(cpu, mask);
 303		}
 304		free_cpumask_var(mask);
 305	} else {
 306		rc = cpum_cf_alloc_cpu(cpu);
 307	}
 308	return rc;
 309}
 310
 311static void cpum_cf_free(int cpu)
 312{
 313	if (cpu == -1) {
 314		for_each_online_cpu(cpu)
 315			cpum_cf_free_cpu(cpu);
 316	} else {
 317		cpum_cf_free_cpu(cpu);
 318	}
 319}
 320
 321#define	CF_DIAG_CTRSET_DEF		0xfeef	/* Counter set header mark */
 322						/* interval in seconds */
 323
 324/* Counter sets are stored as data stream in a page sized memory buffer and
 325 * exported to user space via raw data attached to the event sample data.
 326 * Each counter set starts with an eight byte header consisting of:
 327 * - a two byte eye catcher (0xfeef)
 328 * - a one byte counter set number
 329 * - a two byte counter set size (indicates the number of counters in this set)
 330 * - a three byte reserved value (must be zero) to make the header the same
 331 *   size as a counter value.
 332 * All counter values are eight byte in size.
 333 *
 334 * All counter sets are followed by a 64 byte trailer.
 335 * The trailer consists of a:
 336 * - flag field indicating valid fields when corresponding bit set
 337 * - the counter facility first and second version number
 338 * - the CPU speed if nonzero
 339 * - the time stamp the counter sets have been collected
 340 * - the time of day (TOD) base value
 341 * - the machine type.
 342 *
 343 * The counter sets are saved when the process is prepared to be executed on a
 344 * CPU and saved again when the process is going to be removed from a CPU.
 345 * The difference of both counter sets are calculated and stored in the event
 346 * sample data area.
 347 */
 348struct cf_ctrset_entry {	/* CPU-M CF counter set entry (8 byte) */
 349	unsigned int def:16;	/* 0-15  Data Entry Format */
 350	unsigned int set:16;	/* 16-31 Counter set identifier */
 351	unsigned int ctr:16;	/* 32-47 Number of stored counters */
 352	unsigned int res1:16;	/* 48-63 Reserved */
 353};
 354
 355struct cf_trailer_entry {	/* CPU-M CF_DIAG trailer (64 byte) */
 356	/* 0 - 7 */
 357	union {
 358		struct {
 359			unsigned int clock_base:1;	/* TOD clock base set */
 360			unsigned int speed:1;		/* CPU speed set */
 361			/* Measurement alerts */
 362			unsigned int mtda:1;	/* Loss of MT ctr. data alert */
 363			unsigned int caca:1;	/* Counter auth. change alert */
 364			unsigned int lcda:1;	/* Loss of counter data alert */
 365		};
 366		unsigned long flags;	/* 0-63    All indicators */
 367	};
 368	/* 8 - 15 */
 369	unsigned int cfvn:16;			/* 64-79   Ctr First Version */
 370	unsigned int csvn:16;			/* 80-95   Ctr Second Version */
 371	unsigned int cpu_speed:32;		/* 96-127  CPU speed */
 372	/* 16 - 23 */
 373	unsigned long timestamp;		/* 128-191 Timestamp (TOD) */
 374	/* 24 - 55 */
 375	union {
 376		struct {
 377			unsigned long progusage1;
 378			unsigned long progusage2;
 379			unsigned long progusage3;
 380			unsigned long tod_base;
 381		};
 382		unsigned long progusage[4];
 383	};
 384	/* 56 - 63 */
 385	unsigned int mach_type:16;		/* Machine type */
 386	unsigned int res1:16;			/* Reserved */
 387	unsigned int res2:32;			/* Reserved */
 388};
 389
 390/* Create the trailer data at the end of a page. */
 391static void cfdiag_trailer(struct cf_trailer_entry *te)
 392{
 393	struct cpuid cpuid;
 394
 395	te->cfvn = cpumf_ctr_info.cfvn;		/* Counter version numbers */
 396	te->csvn = cpumf_ctr_info.csvn;
 397
 398	get_cpu_id(&cpuid);			/* Machine type */
 399	te->mach_type = cpuid.machine;
 400	te->cpu_speed = cfdiag_cpu_speed;
 401	if (te->cpu_speed)
 402		te->speed = 1;
 403	te->clock_base = 1;			/* Save clock base */
 404	te->tod_base = tod_clock_base.tod;
 405	te->timestamp = get_tod_clock_fast();
 406}
 407
 408/*
 409 * The number of counters per counter set varies between machine generations,
 410 * but is constant when running on a particular machine generation.
 411 * Determine each counter set size at device driver initialization and
 412 * retrieve it later.
 413 */
 414static size_t cpumf_ctr_setsizes[CPUMF_CTR_SET_MAX];
 415static void cpum_cf_make_setsize(enum cpumf_ctr_set ctrset)
 416{
 417	size_t ctrset_size = 0;
 418
 419	switch (ctrset) {
 420	case CPUMF_CTR_SET_BASIC:
 421		if (cpumf_ctr_info.cfvn >= 1)
 422			ctrset_size = 6;
 423		break;
 424	case CPUMF_CTR_SET_USER:
 425		if (cpumf_ctr_info.cfvn == 1)
 426			ctrset_size = 6;
 427		else if (cpumf_ctr_info.cfvn >= 3)
 428			ctrset_size = 2;
 429		break;
 430	case CPUMF_CTR_SET_CRYPTO:
 431		if (cpumf_ctr_info.csvn >= 1 && cpumf_ctr_info.csvn <= 5)
 432			ctrset_size = 16;
 433		else if (cpumf_ctr_info.csvn >= 6)
 434			ctrset_size = 20;
 435		break;
 436	case CPUMF_CTR_SET_EXT:
 437		if (cpumf_ctr_info.csvn == 1)
 438			ctrset_size = 32;
 439		else if (cpumf_ctr_info.csvn == 2)
 440			ctrset_size = 48;
 441		else if (cpumf_ctr_info.csvn >= 3 && cpumf_ctr_info.csvn <= 5)
 442			ctrset_size = 128;
 443		else if (cpumf_ctr_info.csvn >= 6 && cpumf_ctr_info.csvn <= 8)
 444			ctrset_size = 160;
 445		break;
 446	case CPUMF_CTR_SET_MT_DIAG:
 447		if (cpumf_ctr_info.csvn > 3)
 448			ctrset_size = 48;
 449		break;
 450	case CPUMF_CTR_SET_MAX:
 451		break;
 452	}
 453	cpumf_ctr_setsizes[ctrset] = ctrset_size;
 454}
 455
 456/*
 457 * Return the maximum possible counter set size (in number of 8 byte counters)
 458 * depending on type and model number.
 459 */
 460static size_t cpum_cf_read_setsize(enum cpumf_ctr_set ctrset)
 461{
 462	return cpumf_ctr_setsizes[ctrset];
 463}
 464
 465/* Read a counter set. The counter set number determines the counter set and
 466 * the CPUM-CF first and second version number determine the number of
 467 * available counters in each counter set.
 468 * Each counter set starts with header containing the counter set number and
 469 * the number of eight byte counters.
 470 *
 471 * The functions returns the number of bytes occupied by this counter set
 472 * including the header.
 473 * If there is no counter in the counter set, this counter set is useless and
 474 * zero is returned on this case.
 475 *
 476 * Note that the counter sets may not be enabled or active and the stcctm
 477 * instruction might return error 3. Depending on error_ok value this is ok,
 478 * for example when called from cpumf_pmu_start() call back function.
 479 */
 480static size_t cfdiag_getctrset(struct cf_ctrset_entry *ctrdata, int ctrset,
 481			       size_t room, bool error_ok)
 482{
 483	size_t ctrset_size, need = 0;
 484	int rc = 3;				/* Assume write failure */
 485
 486	ctrdata->def = CF_DIAG_CTRSET_DEF;
 487	ctrdata->set = ctrset;
 488	ctrdata->res1 = 0;
 489	ctrset_size = cpum_cf_read_setsize(ctrset);
 490
 491	if (ctrset_size) {			/* Save data */
 492		need = ctrset_size * sizeof(u64) + sizeof(*ctrdata);
 493		if (need <= room) {
 494			rc = ctr_stcctm(ctrset, ctrset_size,
 495					(u64 *)(ctrdata + 1));
 496		}
 497		if (rc != 3 || error_ok)
 498			ctrdata->ctr = ctrset_size;
 499		else
 500			need = 0;
 501	}
 502
 503	return need;
 504}
 505
 506static const u64 cpumf_ctr_ctl[CPUMF_CTR_SET_MAX] = {
 507	[CPUMF_CTR_SET_BASIC]	= 0x02,
 508	[CPUMF_CTR_SET_USER]	= 0x04,
 509	[CPUMF_CTR_SET_CRYPTO]	= 0x08,
 510	[CPUMF_CTR_SET_EXT]	= 0x01,
 511	[CPUMF_CTR_SET_MT_DIAG] = 0x20,
 512};
 513
 514/* Read out all counter sets and save them in the provided data buffer.
 515 * The last 64 byte host an artificial trailer entry.
 516 */
 517static size_t cfdiag_getctr(void *data, size_t sz, unsigned long auth,
 518			    bool error_ok)
 519{
 520	struct cf_trailer_entry *trailer;
 521	size_t offset = 0, done;
 522	int i;
 523
 524	memset(data, 0, sz);
 525	sz -= sizeof(*trailer);		/* Always room for trailer */
 526	for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
 527		struct cf_ctrset_entry *ctrdata = data + offset;
 528
 529		if (!(auth & cpumf_ctr_ctl[i]))
 530			continue;	/* Counter set not authorized */
 531
 532		done = cfdiag_getctrset(ctrdata, i, sz - offset, error_ok);
 533		offset += done;
 534	}
 535	trailer = data + offset;
 536	cfdiag_trailer(trailer);
 537	return offset + sizeof(*trailer);
 538}
 539
 540/* Calculate the difference for each counter in a counter set. */
 541static void cfdiag_diffctrset(u64 *pstart, u64 *pstop, int counters)
 542{
 543	for (; --counters >= 0; ++pstart, ++pstop)
 544		if (*pstop >= *pstart)
 545			*pstop -= *pstart;
 546		else
 547			*pstop = *pstart - *pstop + 1;
 548}
 549
 550/* Scan the counter sets and calculate the difference of each counter
 551 * in each set. The result is the increment of each counter during the
 552 * period the counter set has been activated.
 553 *
 554 * Return true on success.
 555 */
 556static int cfdiag_diffctr(struct cpu_cf_events *cpuhw, unsigned long auth)
 557{
 558	struct cf_trailer_entry *trailer_start, *trailer_stop;
 559	struct cf_ctrset_entry *ctrstart, *ctrstop;
 560	size_t offset = 0;
 561	int i;
 562
 563	for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
 564		ctrstart = (struct cf_ctrset_entry *)(cpuhw->start + offset);
 565		ctrstop = (struct cf_ctrset_entry *)(cpuhw->stop + offset);
 566
 567		/* Counter set not authorized */
 568		if (!(auth & cpumf_ctr_ctl[i]))
 569			continue;
 570		/* Counter set size zero was not saved */
 571		if (!cpum_cf_read_setsize(i))
 572			continue;
 573
 574		if (memcmp(ctrstop, ctrstart, sizeof(*ctrstop))) {
 575			pr_err_once("cpum_cf_diag counter set compare error "
 576				    "in set %i\n", ctrstart->set);
 577			return 0;
 578		}
 579		if (ctrstart->def == CF_DIAG_CTRSET_DEF) {
 580			cfdiag_diffctrset((u64 *)(ctrstart + 1),
 581					  (u64 *)(ctrstop + 1), ctrstart->ctr);
 582			offset += ctrstart->ctr * sizeof(u64) +
 583							sizeof(*ctrstart);
 584		}
 585	}
 586
 587	/* Save time_stamp from start of event in stop's trailer */
 588	trailer_start = (struct cf_trailer_entry *)(cpuhw->start + offset);
 589	trailer_stop = (struct cf_trailer_entry *)(cpuhw->stop + offset);
 590	trailer_stop->progusage[0] = trailer_start->timestamp;
 591
 592	return 1;
 593}
 594
 595static enum cpumf_ctr_set get_counter_set(u64 event)
 596{
 597	int set = CPUMF_CTR_SET_MAX;
 598
 599	if (event < 32)
 600		set = CPUMF_CTR_SET_BASIC;
 601	else if (event < 64)
 602		set = CPUMF_CTR_SET_USER;
 603	else if (event < 128)
 604		set = CPUMF_CTR_SET_CRYPTO;
 605	else if (event < 288)
 606		set = CPUMF_CTR_SET_EXT;
 607	else if (event >= 448 && event < 496)
 608		set = CPUMF_CTR_SET_MT_DIAG;
 609
 610	return set;
 611}
 612
 613static int validate_ctr_version(const u64 config, enum cpumf_ctr_set set)
 614{
 615	u16 mtdiag_ctl;
 616	int err = 0;
 617
 618	/* check required version for counter sets */
 619	switch (set) {
 620	case CPUMF_CTR_SET_BASIC:
 621	case CPUMF_CTR_SET_USER:
 622		if (cpumf_ctr_info.cfvn < 1)
 623			err = -EOPNOTSUPP;
 624		break;
 625	case CPUMF_CTR_SET_CRYPTO:
 626		if ((cpumf_ctr_info.csvn >= 1 && cpumf_ctr_info.csvn <= 5 &&
 627		     config > 79) || (cpumf_ctr_info.csvn >= 6 && config > 83))
 628			err = -EOPNOTSUPP;
 629		break;
 630	case CPUMF_CTR_SET_EXT:
 631		if (cpumf_ctr_info.csvn < 1)
 632			err = -EOPNOTSUPP;
 633		if ((cpumf_ctr_info.csvn == 1 && config > 159) ||
 634		    (cpumf_ctr_info.csvn == 2 && config > 175) ||
 635		    (cpumf_ctr_info.csvn >= 3 && cpumf_ctr_info.csvn <= 5 &&
 636		     config > 255) ||
 637		    (cpumf_ctr_info.csvn >= 6 && config > 287))
 638			err = -EOPNOTSUPP;
 639		break;
 640	case CPUMF_CTR_SET_MT_DIAG:
 641		if (cpumf_ctr_info.csvn <= 3)
 642			err = -EOPNOTSUPP;
 643		/*
 644		 * MT-diagnostic counters are read-only.  The counter set
 645		 * is automatically enabled and activated on all CPUs with
 646		 * multithreading (SMT).  Deactivation of multithreading
 647		 * also disables the counter set.  State changes are ignored
 648		 * by lcctl().	Because Linux controls SMT enablement through
 649		 * a kernel parameter only, the counter set is either disabled
 650		 * or enabled and active.
 651		 *
 652		 * Thus, the counters can only be used if SMT is on and the
 653		 * counter set is enabled and active.
 654		 */
 655		mtdiag_ctl = cpumf_ctr_ctl[CPUMF_CTR_SET_MT_DIAG];
 656		if (!((cpumf_ctr_info.auth_ctl & mtdiag_ctl) &&
 657		      (cpumf_ctr_info.enable_ctl & mtdiag_ctl) &&
 658		      (cpumf_ctr_info.act_ctl & mtdiag_ctl)))
 659			err = -EOPNOTSUPP;
 660		break;
 661	case CPUMF_CTR_SET_MAX:
 662		err = -EOPNOTSUPP;
 663	}
 664
 665	return err;
 666}
 667
 668/*
 669 * Change the CPUMF state to active.
 670 * Enable and activate the CPU-counter sets according
 671 * to the per-cpu control state.
 672 */
 673static void cpumf_pmu_enable(struct pmu *pmu)
 674{
 675	struct cpu_cf_events *cpuhw = this_cpu_cfhw();
 676	int err;
 677
 678	if (!cpuhw || (cpuhw->flags & PMU_F_ENABLED))
 679		return;
 680
 681	err = lcctl(cpuhw->state | cpuhw->dev_state);
 682	if (err)
 683		pr_err("Enabling the performance measuring unit failed with rc=%x\n", err);
 684	else
 685		cpuhw->flags |= PMU_F_ENABLED;
 686}
 687
 688/*
 689 * Change the CPUMF state to inactive.
 690 * Disable and enable (inactive) the CPU-counter sets according
 691 * to the per-cpu control state.
 692 */
 693static void cpumf_pmu_disable(struct pmu *pmu)
 694{
 695	struct cpu_cf_events *cpuhw = this_cpu_cfhw();
 696	u64 inactive;
 697	int err;
 698
 699	if (!cpuhw || !(cpuhw->flags & PMU_F_ENABLED))
 700		return;
 701
 702	inactive = cpuhw->state & ~((1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1);
 703	inactive |= cpuhw->dev_state;
 704	err = lcctl(inactive);
 705	if (err)
 706		pr_err("Disabling the performance measuring unit failed with rc=%x\n", err);
 707	else
 708		cpuhw->flags &= ~PMU_F_ENABLED;
 709}
 710
 711/* Release the PMU if event is the last perf event */
 712static void hw_perf_event_destroy(struct perf_event *event)
 713{
 714	cpum_cf_free(event->cpu);
 715}
 716
 717/* CPUMF <-> perf event mappings for kernel+userspace (basic set) */
 718static const int cpumf_generic_events_basic[] = {
 719	[PERF_COUNT_HW_CPU_CYCLES]	    = 0,
 720	[PERF_COUNT_HW_INSTRUCTIONS]	    = 1,
 721	[PERF_COUNT_HW_CACHE_REFERENCES]    = -1,
 722	[PERF_COUNT_HW_CACHE_MISSES]	    = -1,
 723	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = -1,
 724	[PERF_COUNT_HW_BRANCH_MISSES]	    = -1,
 725	[PERF_COUNT_HW_BUS_CYCLES]	    = -1,
 726};
 727/* CPUMF <-> perf event mappings for userspace (problem-state set) */
 728static const int cpumf_generic_events_user[] = {
 729	[PERF_COUNT_HW_CPU_CYCLES]	    = 32,
 730	[PERF_COUNT_HW_INSTRUCTIONS]	    = 33,
 731	[PERF_COUNT_HW_CACHE_REFERENCES]    = -1,
 732	[PERF_COUNT_HW_CACHE_MISSES]	    = -1,
 733	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = -1,
 734	[PERF_COUNT_HW_BRANCH_MISSES]	    = -1,
 735	[PERF_COUNT_HW_BUS_CYCLES]	    = -1,
 736};
 737
 738static int is_userspace_event(u64 ev)
 739{
 740	return cpumf_generic_events_user[PERF_COUNT_HW_CPU_CYCLES] == ev ||
 741	       cpumf_generic_events_user[PERF_COUNT_HW_INSTRUCTIONS] == ev;
 742}
 743
 744static int __hw_perf_event_init(struct perf_event *event, unsigned int type)
 745{
 746	struct perf_event_attr *attr = &event->attr;
 747	struct hw_perf_event *hwc = &event->hw;
 748	enum cpumf_ctr_set set;
 749	u64 ev;
 750
 751	switch (type) {
 752	case PERF_TYPE_RAW:
 753		/* Raw events are used to access counters directly,
 754		 * hence do not permit excludes */
 755		if (attr->exclude_kernel || attr->exclude_user ||
 756		    attr->exclude_hv)
 757			return -EOPNOTSUPP;
 758		ev = attr->config;
 759		break;
 760
 761	case PERF_TYPE_HARDWARE:
 762		ev = attr->config;
 763		if (!attr->exclude_user && attr->exclude_kernel) {
 764			/*
 765			 * Count user space (problem-state) only
 766			 * Handle events 32 and 33 as 0:u and 1:u
 767			 */
 768			if (!is_userspace_event(ev)) {
 769				if (ev >= ARRAY_SIZE(cpumf_generic_events_user))
 770					return -EOPNOTSUPP;
 771				ev = cpumf_generic_events_user[ev];
 772			}
 773		} else if (!attr->exclude_kernel && attr->exclude_user) {
 774			/* No support for kernel space counters only */
 775			return -EOPNOTSUPP;
 776		} else {
 777			/* Count user and kernel space, incl. events 32 + 33 */
 778			if (!is_userspace_event(ev)) {
 779				if (ev >= ARRAY_SIZE(cpumf_generic_events_basic))
 780					return -EOPNOTSUPP;
 781				ev = cpumf_generic_events_basic[ev];
 782			}
 783		}
 784		break;
 785
 786	default:
 787		return -ENOENT;
 788	}
 789
 790	if (ev == -1)
 791		return -ENOENT;
 792
 793	if (ev > PERF_CPUM_CF_MAX_CTR)
 794		return -ENOENT;
 795
 796	/* Obtain the counter set to which the specified counter belongs */
 797	set = get_counter_set(ev);
 798	switch (set) {
 799	case CPUMF_CTR_SET_BASIC:
 800	case CPUMF_CTR_SET_USER:
 801	case CPUMF_CTR_SET_CRYPTO:
 802	case CPUMF_CTR_SET_EXT:
 803	case CPUMF_CTR_SET_MT_DIAG:
 804		/*
 805		 * Use the hardware perf event structure to store the
 806		 * counter number in the 'config' member and the counter
 807		 * set number in the 'config_base' as bit mask.
 808		 * It is later used to enable/disable the counter(s).
 809		 */
 810		hwc->config = ev;
 811		hwc->config_base = cpumf_ctr_ctl[set];
 812		break;
 813	case CPUMF_CTR_SET_MAX:
 814		/* The counter could not be associated to a counter set */
 815		return -EINVAL;
 816	}
 817
 818	/* Initialize for using the CPU-measurement counter facility */
 819	if (cpum_cf_alloc(event->cpu))
 820		return -ENOMEM;
 821	event->destroy = hw_perf_event_destroy;
 822
 823	/*
 824	 * Finally, validate version and authorization of the counter set.
 825	 * If the particular CPU counter set is not authorized,
 826	 * return with -ENOENT in order to fall back to other
 827	 * PMUs that might suffice the event request.
 828	 */
 829	if (!(hwc->config_base & cpumf_ctr_info.auth_ctl))
 830		return -ENOENT;
 831	return validate_ctr_version(hwc->config, set);
 832}
 833
 834/* Events CPU_CYCLES and INSTRUCTIONS can be submitted with two different
 835 * attribute::type values:
 836 * - PERF_TYPE_HARDWARE:
 837 * - pmu->type:
 838 * Handle both type of invocations identical. They address the same hardware.
 839 * The result is different when event modifiers exclude_kernel and/or
 840 * exclude_user are also set.
 841 */
 842static int cpumf_pmu_event_type(struct perf_event *event)
 843{
 844	u64 ev = event->attr.config;
 845
 846	if (cpumf_generic_events_basic[PERF_COUNT_HW_CPU_CYCLES] == ev ||
 847	    cpumf_generic_events_basic[PERF_COUNT_HW_INSTRUCTIONS] == ev ||
 848	    cpumf_generic_events_user[PERF_COUNT_HW_CPU_CYCLES] == ev ||
 849	    cpumf_generic_events_user[PERF_COUNT_HW_INSTRUCTIONS] == ev)
 850		return PERF_TYPE_HARDWARE;
 851	return PERF_TYPE_RAW;
 852}
 853
 854static int cpumf_pmu_event_init(struct perf_event *event)
 855{
 856	unsigned int type = event->attr.type;
 857	int err = -ENOENT;
 858
 859	if (is_sampling_event(event))	/* No sampling support */
 860		return err;
 861	if (type == PERF_TYPE_HARDWARE || type == PERF_TYPE_RAW)
 862		err = __hw_perf_event_init(event, type);
 863	else if (event->pmu->type == type)
 864		/* Registered as unknown PMU */
 865		err = __hw_perf_event_init(event, cpumf_pmu_event_type(event));
 866
 867	return err;
 868}
 869
 870static int hw_perf_event_reset(struct perf_event *event)
 871{
 872	u64 prev, new;
 873	int err;
 874
 875	prev = local64_read(&event->hw.prev_count);
 876	do {
 877		err = ecctr(event->hw.config, &new);
 878		if (err) {
 879			if (err != 3)
 880				break;
 881			/* The counter is not (yet) available. This
 882			 * might happen if the counter set to which
 883			 * this counter belongs is in the disabled
 884			 * state.
 885			 */
 886			new = 0;
 887		}
 888	} while (!local64_try_cmpxchg(&event->hw.prev_count, &prev, new));
 889
 890	return err;
 891}
 892
 893static void hw_perf_event_update(struct perf_event *event)
 894{
 895	u64 prev, new, delta;
 896	int err;
 897
 898	prev = local64_read(&event->hw.prev_count);
 899	do {
 900		err = ecctr(event->hw.config, &new);
 901		if (err)
 902			return;
 903	} while (!local64_try_cmpxchg(&event->hw.prev_count, &prev, new));
 904
 905	delta = (prev <= new) ? new - prev
 906			      : (-1ULL - prev) + new + 1;	 /* overflow */
 907	local64_add(delta, &event->count);
 908}
 909
 910static void cpumf_pmu_read(struct perf_event *event)
 911{
 912	if (event->hw.state & PERF_HES_STOPPED)
 913		return;
 914
 915	hw_perf_event_update(event);
 916}
 917
 918static void cpumf_pmu_start(struct perf_event *event, int flags)
 919{
 920	struct cpu_cf_events *cpuhw = this_cpu_cfhw();
 921	struct hw_perf_event *hwc = &event->hw;
 922	int i;
 923
 924	if (!(hwc->state & PERF_HES_STOPPED))
 925		return;
 926
 927	hwc->state = 0;
 928
 929	/* (Re-)enable and activate the counter set */
 930	ctr_set_enable(&cpuhw->state, hwc->config_base);
 931	ctr_set_start(&cpuhw->state, hwc->config_base);
 932
 933	/* The counter set to which this counter belongs can be already active.
 934	 * Because all counters in a set are active, the event->hw.prev_count
 935	 * needs to be synchronized.  At this point, the counter set can be in
 936	 * the inactive or disabled state.
 937	 */
 938	if (hwc->config == PERF_EVENT_CPUM_CF_DIAG) {
 939		cpuhw->usedss = cfdiag_getctr(cpuhw->start,
 940					      sizeof(cpuhw->start),
 941					      hwc->config_base, true);
 942	} else {
 943		hw_perf_event_reset(event);
 944	}
 945
 946	/* Increment refcount for counter sets */
 947	for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i)
 948		if ((hwc->config_base & cpumf_ctr_ctl[i]))
 949			atomic_inc(&cpuhw->ctr_set[i]);
 950}
 951
 952/* Create perf event sample with the counter sets as raw data.	The sample
 953 * is then pushed to the event subsystem and the function checks for
 954 * possible event overflows. If an event overflow occurs, the PMU is
 955 * stopped.
 956 *
 957 * Return non-zero if an event overflow occurred.
 958 */
 959static int cfdiag_push_sample(struct perf_event *event,
 960			      struct cpu_cf_events *cpuhw)
 961{
 962	struct perf_sample_data data;
 963	struct perf_raw_record raw;
 964	struct pt_regs regs;
 965	int overflow;
 966
 967	/* Setup perf sample */
 968	perf_sample_data_init(&data, 0, event->hw.last_period);
 969	memset(&regs, 0, sizeof(regs));
 970	memset(&raw, 0, sizeof(raw));
 971
 972	if (event->attr.sample_type & PERF_SAMPLE_CPU)
 973		data.cpu_entry.cpu = event->cpu;
 974	if (event->attr.sample_type & PERF_SAMPLE_RAW) {
 975		raw.frag.size = cpuhw->usedss;
 976		raw.frag.data = cpuhw->stop;
 977		perf_sample_save_raw_data(&data, event, &raw);
 978	}
 979
 980	overflow = perf_event_overflow(event, &data, &regs);
 981
 982	perf_event_update_userpage(event);
 983	return overflow;
 984}
 985
 986static void cpumf_pmu_stop(struct perf_event *event, int flags)
 987{
 988	struct cpu_cf_events *cpuhw = this_cpu_cfhw();
 989	struct hw_perf_event *hwc = &event->hw;
 990	int i;
 991
 992	if (!(hwc->state & PERF_HES_STOPPED)) {
 993		/* Decrement reference count for this counter set and if this
 994		 * is the last used counter in the set, clear activation
 995		 * control and set the counter set state to inactive.
 996		 */
 997		for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
 998			if (!(hwc->config_base & cpumf_ctr_ctl[i]))
 999				continue;
1000			if (!atomic_dec_return(&cpuhw->ctr_set[i]))
1001				ctr_set_stop(&cpuhw->state, cpumf_ctr_ctl[i]);
1002		}
1003		hwc->state |= PERF_HES_STOPPED;
1004	}
1005
1006	if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
1007		if (hwc->config == PERF_EVENT_CPUM_CF_DIAG) {
1008			local64_inc(&event->count);
1009			cpuhw->usedss = cfdiag_getctr(cpuhw->stop,
1010						      sizeof(cpuhw->stop),
1011						      event->hw.config_base,
1012						      false);
1013			if (cfdiag_diffctr(cpuhw, event->hw.config_base))
1014				cfdiag_push_sample(event, cpuhw);
1015		} else {
1016			hw_perf_event_update(event);
1017		}
1018		hwc->state |= PERF_HES_UPTODATE;
1019	}
1020}
1021
1022static int cpumf_pmu_add(struct perf_event *event, int flags)
1023{
1024	struct cpu_cf_events *cpuhw = this_cpu_cfhw();
1025
1026	ctr_set_enable(&cpuhw->state, event->hw.config_base);
1027	event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
1028
1029	if (flags & PERF_EF_START)
1030		cpumf_pmu_start(event, PERF_EF_RELOAD);
1031
1032	return 0;
1033}
1034
1035static void cpumf_pmu_del(struct perf_event *event, int flags)
1036{
1037	struct cpu_cf_events *cpuhw = this_cpu_cfhw();
1038	int i;
1039
1040	cpumf_pmu_stop(event, PERF_EF_UPDATE);
1041
1042	/* Check if any counter in the counter set is still used.  If not used,
1043	 * change the counter set to the disabled state.  This also clears the
1044	 * content of all counters in the set.
1045	 *
1046	 * When a new perf event has been added but not yet started, this can
1047	 * clear enable control and resets all counters in a set.  Therefore,
1048	 * cpumf_pmu_start() always has to re-enable a counter set.
1049	 */
1050	for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i)
1051		if (!atomic_read(&cpuhw->ctr_set[i]))
1052			ctr_set_disable(&cpuhw->state, cpumf_ctr_ctl[i]);
1053}
1054
1055/* Performance monitoring unit for s390x */
1056static struct pmu cpumf_pmu = {
1057	.task_ctx_nr  = perf_sw_context,
1058	.capabilities = PERF_PMU_CAP_NO_INTERRUPT,
1059	.pmu_enable   = cpumf_pmu_enable,
1060	.pmu_disable  = cpumf_pmu_disable,
1061	.event_init   = cpumf_pmu_event_init,
1062	.add	      = cpumf_pmu_add,
1063	.del	      = cpumf_pmu_del,
1064	.start	      = cpumf_pmu_start,
1065	.stop	      = cpumf_pmu_stop,
1066	.read	      = cpumf_pmu_read,
1067};
1068
1069static struct cfset_session {		/* CPUs and counter set bit mask */
1070	struct list_head head;		/* Head of list of active processes */
1071} cfset_session = {
1072	.head = LIST_HEAD_INIT(cfset_session.head)
1073};
1074
1075static refcount_t cfset_opencnt = REFCOUNT_INIT(0);	/* Access count */
1076/*
1077 * Synchronize access to device /dev/hwc. This mutex protects against
1078 * concurrent access to functions cfset_open() and cfset_release().
1079 * Same for CPU hotplug add and remove events triggering
1080 * cpum_cf_online_cpu() and cpum_cf_offline_cpu().
1081 * It also serializes concurrent device ioctl access from multiple
1082 * processes accessing /dev/hwc.
1083 *
1084 * The mutex protects concurrent access to the /dev/hwctr session management
1085 * struct cfset_session and reference counting variable cfset_opencnt.
1086 */
1087static DEFINE_MUTEX(cfset_ctrset_mutex);
1088
1089/*
1090 * CPU hotplug handles only /dev/hwctr device.
1091 * For perf_event_open() the CPU hotplug handling is done on kernel common
1092 * code:
1093 * - CPU add: Nothing is done since a file descriptor can not be created
1094 *   and returned to the user.
1095 * - CPU delete: Handled by common code via pmu_disable(), pmu_stop() and
1096 *   pmu_delete(). The event itself is removed when the file descriptor is
1097 *   closed.
1098 */
1099static int cfset_online_cpu(unsigned int cpu);
1100
1101static int cpum_cf_online_cpu(unsigned int cpu)
1102{
1103	int rc = 0;
1104
1105	/*
1106	 * Ignore notification for perf_event_open().
1107	 * Handle only /dev/hwctr device sessions.
1108	 */
1109	mutex_lock(&cfset_ctrset_mutex);
1110	if (refcount_read(&cfset_opencnt)) {
1111		rc = cpum_cf_alloc_cpu(cpu);
1112		if (!rc)
1113			cfset_online_cpu(cpu);
1114	}
1115	mutex_unlock(&cfset_ctrset_mutex);
1116	return rc;
1117}
1118
1119static int cfset_offline_cpu(unsigned int cpu);
1120
1121static int cpum_cf_offline_cpu(unsigned int cpu)
1122{
1123	/*
1124	 * During task exit processing of grouped perf events triggered by CPU
1125	 * hotplug processing, pmu_disable() is called as part of perf context
1126	 * removal process. Therefore do not trigger event removal now for
1127	 * perf_event_open() created events. Perf common code triggers event
1128	 * destruction when the event file descriptor is closed.
1129	 *
1130	 * Handle only /dev/hwctr device sessions.
1131	 */
1132	mutex_lock(&cfset_ctrset_mutex);
1133	if (refcount_read(&cfset_opencnt)) {
1134		cfset_offline_cpu(cpu);
1135		cpum_cf_free_cpu(cpu);
1136	}
1137	mutex_unlock(&cfset_ctrset_mutex);
1138	return 0;
1139}
1140
1141/* Return true if store counter set multiple instruction is available */
1142static inline int stccm_avail(void)
1143{
1144	return test_facility(142);
1145}
1146
1147/* CPU-measurement alerts for the counter facility */
1148static void cpumf_measurement_alert(struct ext_code ext_code,
1149				    unsigned int alert, unsigned long unused)
1150{
1151	struct cpu_cf_events *cpuhw;
1152
1153	if (!(alert & CPU_MF_INT_CF_MASK))
1154		return;
1155
1156	inc_irq_stat(IRQEXT_CMC);
1157
1158	/*
1159	 * Measurement alerts are shared and might happen when the PMU
1160	 * is not reserved.  Ignore these alerts in this case.
1161	 */
1162	cpuhw = this_cpu_cfhw();
1163	if (!cpuhw)
1164		return;
1165
1166	/* counter authorization change alert */
1167	if (alert & CPU_MF_INT_CF_CACA)
1168		qctri(&cpumf_ctr_info);
1169
1170	/* loss of counter data alert */
1171	if (alert & CPU_MF_INT_CF_LCDA)
1172		pr_err("CPU[%i] Counter data was lost\n", smp_processor_id());
1173
1174	/* loss of MT counter data alert */
1175	if (alert & CPU_MF_INT_CF_MTDA)
1176		pr_warn("CPU[%i] MT counter data was lost\n",
1177			smp_processor_id());
1178}
1179
1180static int cfset_init(void);
1181static int __init cpumf_pmu_init(void)
1182{
1183	int rc;
1184
1185	/* Extract counter measurement facility information */
1186	if (!cpum_cf_avail() || qctri(&cpumf_ctr_info))
1187		return -ENODEV;
1188
1189	/* Determine and store counter set sizes for later reference */
1190	for (rc = CPUMF_CTR_SET_BASIC; rc < CPUMF_CTR_SET_MAX; ++rc)
1191		cpum_cf_make_setsize(rc);
1192
1193	/*
1194	 * Clear bit 15 of cr0 to unauthorize problem-state to
1195	 * extract measurement counters
1196	 */
1197	system_ctl_clear_bit(0, CR0_CPUMF_EXTRACTION_AUTH_BIT);
1198
1199	/* register handler for measurement-alert interruptions */
1200	rc = register_external_irq(EXT_IRQ_MEASURE_ALERT,
1201				   cpumf_measurement_alert);
1202	if (rc) {
1203		pr_err("Registering for CPU-measurement alerts failed with rc=%i\n", rc);
1204		return rc;
1205	}
1206
1207	/* Setup s390dbf facility */
1208	cf_dbg = debug_register("cpum_cf", 2, 1, 128);
1209	if (!cf_dbg) {
1210		pr_err("Registration of s390dbf(cpum_cf) failed\n");
1211		rc = -ENOMEM;
1212		goto out1;
1213	}
1214	debug_register_view(cf_dbg, &debug_sprintf_view);
1215
1216	cpumf_pmu.attr_groups = cpumf_cf_event_group();
1217	rc = perf_pmu_register(&cpumf_pmu, "cpum_cf", -1);
1218	if (rc) {
1219		pr_err("Registering the cpum_cf PMU failed with rc=%i\n", rc);
1220		goto out2;
1221	} else if (stccm_avail()) {	/* Setup counter set device */
1222		cfset_init();
1223	}
1224
1225	rc = cpuhp_setup_state(CPUHP_AP_PERF_S390_CF_ONLINE,
1226			       "perf/s390/cf:online",
1227			       cpum_cf_online_cpu, cpum_cf_offline_cpu);
1228	return rc;
1229
1230out2:
1231	debug_unregister_view(cf_dbg, &debug_sprintf_view);
1232	debug_unregister(cf_dbg);
1233out1:
1234	unregister_external_irq(EXT_IRQ_MEASURE_ALERT, cpumf_measurement_alert);
1235	return rc;
1236}
1237
1238/* Support for the CPU Measurement Facility counter set extraction using
1239 * device /dev/hwctr. This allows user space programs to extract complete
1240 * counter set via normal file operations.
1241 */
1242
1243struct cfset_call_on_cpu_parm {		/* Parm struct for smp_call_on_cpu */
1244	unsigned int sets;		/* Counter set bit mask */
1245	atomic_t cpus_ack;		/* # CPUs successfully executed func */
1246};
1247
1248struct cfset_request {			/* CPUs and counter set bit mask */
1249	unsigned long ctrset;		/* Bit mask of counter set to read */
1250	cpumask_t mask;			/* CPU mask to read from */
1251	struct list_head node;		/* Chain to cfset_session.head */
1252};
1253
1254static void cfset_session_init(void)
1255{
1256	INIT_LIST_HEAD(&cfset_session.head);
1257}
1258
1259/* Remove current request from global bookkeeping. Maintain a counter set bit
1260 * mask on a per CPU basis.
1261 * Done in process context under mutex protection.
1262 */
1263static void cfset_session_del(struct cfset_request *p)
1264{
1265	list_del(&p->node);
1266}
1267
1268/* Add current request to global bookkeeping. Maintain a counter set bit mask
1269 * on a per CPU basis.
1270 * Done in process context under mutex protection.
1271 */
1272static void cfset_session_add(struct cfset_request *p)
1273{
1274	list_add(&p->node, &cfset_session.head);
1275}
1276
1277/* The /dev/hwctr device access uses PMU_F_IN_USE to mark the device access
1278 * path is currently used.
1279 * The cpu_cf_events::dev_state is used to denote counter sets in use by this
1280 * interface. It is always or'ed in. If this interface is not active, its
1281 * value is zero and no additional counter sets will be included.
1282 *
1283 * The cpu_cf_events::state is used by the perf_event_open SVC and remains
1284 * unchanged.
1285 *
1286 * perf_pmu_enable() and perf_pmu_enable() and its call backs
1287 * cpumf_pmu_enable() and  cpumf_pmu_disable() are called by the
1288 * performance measurement subsystem to enable per process
1289 * CPU Measurement counter facility.
1290 * The XXX_enable() and XXX_disable functions are used to turn off
1291 * x86 performance monitoring interrupt (PMI) during scheduling.
1292 * s390 uses these calls to temporarily stop and resume the active CPU
1293 * counters sets during scheduling.
1294 *
1295 * We do allow concurrent access of perf_event_open() SVC and /dev/hwctr
1296 * device access.  The perf_event_open() SVC interface makes a lot of effort
1297 * to only run the counters while the calling process is actively scheduled
1298 * to run.
1299 * When /dev/hwctr interface is also used at the same time, the counter sets
1300 * will keep running, even when the process is scheduled off a CPU.
1301 * However this is not a problem and does not lead to wrong counter values
1302 * for the perf_event_open() SVC. The current counter value will be recorded
1303 * during schedule-in. At schedule-out time the current counter value is
1304 * extracted again and the delta is calculated and added to the event.
1305 */
1306/* Stop all counter sets via ioctl interface */
1307static void cfset_ioctl_off(void *parm)
1308{
1309	struct cpu_cf_events *cpuhw = this_cpu_cfhw();
1310	struct cfset_call_on_cpu_parm *p = parm;
1311	int rc;
1312
1313	/* Check if any counter set used by /dev/hwctr */
1314	for (rc = CPUMF_CTR_SET_BASIC; rc < CPUMF_CTR_SET_MAX; ++rc)
1315		if ((p->sets & cpumf_ctr_ctl[rc])) {
1316			if (!atomic_dec_return(&cpuhw->ctr_set[rc])) {
1317				ctr_set_disable(&cpuhw->dev_state,
1318						cpumf_ctr_ctl[rc]);
1319				ctr_set_stop(&cpuhw->dev_state,
1320					     cpumf_ctr_ctl[rc]);
1321			}
1322		}
1323	/* Keep perf_event_open counter sets */
1324	rc = lcctl(cpuhw->dev_state | cpuhw->state);
1325	if (rc)
1326		pr_err("Counter set stop %#llx of /dev/%s failed rc=%i\n",
1327		       cpuhw->state, S390_HWCTR_DEVICE, rc);
1328	if (!cpuhw->dev_state)
1329		cpuhw->flags &= ~PMU_F_IN_USE;
1330}
1331
1332/* Start counter sets on particular CPU */
1333static void cfset_ioctl_on(void *parm)
1334{
1335	struct cpu_cf_events *cpuhw = this_cpu_cfhw();
1336	struct cfset_call_on_cpu_parm *p = parm;
1337	int rc;
1338
1339	cpuhw->flags |= PMU_F_IN_USE;
1340	ctr_set_enable(&cpuhw->dev_state, p->sets);
1341	ctr_set_start(&cpuhw->dev_state, p->sets);
1342	for (rc = CPUMF_CTR_SET_BASIC; rc < CPUMF_CTR_SET_MAX; ++rc)
1343		if ((p->sets & cpumf_ctr_ctl[rc]))
1344			atomic_inc(&cpuhw->ctr_set[rc]);
1345	rc = lcctl(cpuhw->dev_state | cpuhw->state);	/* Start counter sets */
1346	if (!rc)
1347		atomic_inc(&p->cpus_ack);
1348	else
1349		pr_err("Counter set start %#llx of /dev/%s failed rc=%i\n",
1350		       cpuhw->dev_state | cpuhw->state, S390_HWCTR_DEVICE, rc);
1351}
1352
1353static void cfset_release_cpu(void *p)
1354{
1355	struct cpu_cf_events *cpuhw = this_cpu_cfhw();
1356	int rc;
1357
1358	cpuhw->dev_state = 0;
1359	rc = lcctl(cpuhw->state);	/* Keep perf_event_open counter sets */
1360	if (rc)
1361		pr_err("Counter set release %#llx of /dev/%s failed rc=%i\n",
1362		       cpuhw->state, S390_HWCTR_DEVICE, rc);
1363}
1364
1365/* This modifies the process CPU mask to adopt it to the currently online
1366 * CPUs. Offline CPUs can not be addresses. This call terminates the access
1367 * and is usually followed by close() or a new iotcl(..., START, ...) which
1368 * creates a new request structure.
1369 */
1370static void cfset_all_stop(struct cfset_request *req)
1371{
1372	struct cfset_call_on_cpu_parm p = {
1373		.sets = req->ctrset,
1374	};
1375
1376	cpumask_and(&req->mask, &req->mask, cpu_online_mask);
1377	on_each_cpu_mask(&req->mask, cfset_ioctl_off, &p, 1);
1378}
1379
1380/* Release function is also called when application gets terminated without
1381 * doing a proper ioctl(..., S390_HWCTR_STOP, ...) command.
1382 */
1383static int cfset_release(struct inode *inode, struct file *file)
1384{
1385	mutex_lock(&cfset_ctrset_mutex);
1386	/* Open followed by close/exit has no private_data */
1387	if (file->private_data) {
1388		cfset_all_stop(file->private_data);
1389		cfset_session_del(file->private_data);
1390		kfree(file->private_data);
1391		file->private_data = NULL;
1392	}
1393	if (refcount_dec_and_test(&cfset_opencnt)) {	/* Last close */
1394		on_each_cpu(cfset_release_cpu, NULL, 1);
1395		cpum_cf_free(-1);
1396	}
1397	mutex_unlock(&cfset_ctrset_mutex);
1398	return 0;
1399}
1400
1401/*
1402 * Open via /dev/hwctr device. Allocate all per CPU resources on the first
1403 * open of the device. The last close releases all per CPU resources.
1404 * Parallel perf_event_open system calls also use per CPU resources.
1405 * These invocations are handled via reference counting on the per CPU data
1406 * structures.
1407 */
1408static int cfset_open(struct inode *inode, struct file *file)
1409{
1410	int rc = 0;
1411
1412	if (!perfmon_capable())
1413		return -EPERM;
1414	file->private_data = NULL;
1415
1416	mutex_lock(&cfset_ctrset_mutex);
1417	if (!refcount_inc_not_zero(&cfset_opencnt)) {	/* First open */
1418		rc = cpum_cf_alloc(-1);
1419		if (!rc) {
1420			cfset_session_init();
1421			refcount_set(&cfset_opencnt, 1);
1422		}
1423	}
1424	mutex_unlock(&cfset_ctrset_mutex);
1425
1426	/* nonseekable_open() never fails */
1427	return rc ?: nonseekable_open(inode, file);
1428}
1429
1430static int cfset_all_start(struct cfset_request *req)
1431{
1432	struct cfset_call_on_cpu_parm p = {
1433		.sets = req->ctrset,
1434		.cpus_ack = ATOMIC_INIT(0),
1435	};
1436	cpumask_var_t mask;
1437	int rc = 0;
1438
1439	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
1440		return -ENOMEM;
1441	cpumask_and(mask, &req->mask, cpu_online_mask);
1442	on_each_cpu_mask(mask, cfset_ioctl_on, &p, 1);
1443	if (atomic_read(&p.cpus_ack) != cpumask_weight(mask)) {
1444		on_each_cpu_mask(mask, cfset_ioctl_off, &p, 1);
1445		rc = -EIO;
1446	}
1447	free_cpumask_var(mask);
1448	return rc;
1449}
1450
1451/* Return the maximum required space for all possible CPUs in case one
1452 * CPU will be onlined during the START, READ, STOP cycles.
1453 * To find out the size of the counter sets, any one CPU will do. They
1454 * all have the same counter sets.
1455 */
1456static size_t cfset_needspace(unsigned int sets)
1457{
1458	size_t bytes = 0;
1459	int i;
1460
1461	for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
1462		if (!(sets & cpumf_ctr_ctl[i]))
1463			continue;
1464		bytes += cpum_cf_read_setsize(i) * sizeof(u64) +
1465			 sizeof(((struct s390_ctrset_setdata *)0)->set) +
1466			 sizeof(((struct s390_ctrset_setdata *)0)->no_cnts);
1467	}
1468	bytes = sizeof(((struct s390_ctrset_read *)0)->no_cpus) + nr_cpu_ids *
1469		(bytes + sizeof(((struct s390_ctrset_cpudata *)0)->cpu_nr) +
1470		     sizeof(((struct s390_ctrset_cpudata *)0)->no_sets));
1471	return bytes;
1472}
1473
1474static int cfset_all_copy(unsigned long arg, cpumask_t *mask)
1475{
1476	struct s390_ctrset_read __user *ctrset_read;
1477	unsigned int cpu, cpus, rc = 0;
1478	void __user *uptr;
1479
1480	ctrset_read = (struct s390_ctrset_read __user *)arg;
1481	uptr = ctrset_read->data;
1482	for_each_cpu(cpu, mask) {
1483		struct cpu_cf_events *cpuhw = get_cpu_cfhw(cpu);
1484		struct s390_ctrset_cpudata __user *ctrset_cpudata;
1485
1486		ctrset_cpudata = uptr;
1487		rc  = put_user(cpu, &ctrset_cpudata->cpu_nr);
1488		rc |= put_user(cpuhw->sets, &ctrset_cpudata->no_sets);
1489		rc |= copy_to_user(ctrset_cpudata->data, cpuhw->data,
1490				   cpuhw->used);
1491		if (rc) {
1492			rc = -EFAULT;
1493			goto out;
1494		}
1495		uptr += sizeof(struct s390_ctrset_cpudata) + cpuhw->used;
1496		cond_resched();
1497	}
1498	cpus = cpumask_weight(mask);
1499	if (put_user(cpus, &ctrset_read->no_cpus))
1500		rc = -EFAULT;
1501out:
1502	return rc;
1503}
1504
1505static size_t cfset_cpuset_read(struct s390_ctrset_setdata *p, int ctrset,
1506				int ctrset_size, size_t room)
1507{
1508	size_t need = 0;
1509	int rc = -1;
1510
1511	need = sizeof(*p) + sizeof(u64) * ctrset_size;
1512	if (need <= room) {
1513		p->set = cpumf_ctr_ctl[ctrset];
1514		p->no_cnts = ctrset_size;
1515		rc = ctr_stcctm(ctrset, ctrset_size, (u64 *)p->cv);
1516		if (rc == 3)		/* Nothing stored */
1517			need = 0;
1518	}
1519	return need;
1520}
1521
1522/* Read all counter sets. */
1523static void cfset_cpu_read(void *parm)
1524{
1525	struct cpu_cf_events *cpuhw = this_cpu_cfhw();
1526	struct cfset_call_on_cpu_parm *p = parm;
1527	int set, set_size;
1528	size_t space;
1529
1530	/* No data saved yet */
1531	cpuhw->used = 0;
1532	cpuhw->sets = 0;
1533	memset(cpuhw->data, 0, sizeof(cpuhw->data));
1534
1535	/* Scan the counter sets */
1536	for (set = CPUMF_CTR_SET_BASIC; set < CPUMF_CTR_SET_MAX; ++set) {
1537		struct s390_ctrset_setdata *sp = (void *)cpuhw->data +
1538						 cpuhw->used;
1539
1540		if (!(p->sets & cpumf_ctr_ctl[set]))
1541			continue;	/* Counter set not in list */
1542		set_size = cpum_cf_read_setsize(set);
1543		space = sizeof(cpuhw->data) - cpuhw->used;
1544		space = cfset_cpuset_read(sp, set, set_size, space);
1545		if (space) {
1546			cpuhw->used += space;
1547			cpuhw->sets += 1;
1548		}
1549	}
1550}
1551
1552static int cfset_all_read(unsigned long arg, struct cfset_request *req)
1553{
1554	struct cfset_call_on_cpu_parm p;
1555	cpumask_var_t mask;
1556	int rc;
1557
1558	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
1559		return -ENOMEM;
1560
1561	p.sets = req->ctrset;
1562	cpumask_and(mask, &req->mask, cpu_online_mask);
1563	on_each_cpu_mask(mask, cfset_cpu_read, &p, 1);
1564	rc = cfset_all_copy(arg, mask);
1565	free_cpumask_var(mask);
1566	return rc;
1567}
1568
1569static long cfset_ioctl_read(unsigned long arg, struct cfset_request *req)
1570{
1571	int ret = -ENODATA;
1572
1573	if (req && req->ctrset)
1574		ret = cfset_all_read(arg, req);
1575	return ret;
1576}
1577
1578static long cfset_ioctl_stop(struct file *file)
1579{
1580	struct cfset_request *req = file->private_data;
1581	int ret = -ENXIO;
1582
1583	if (req) {
1584		cfset_all_stop(req);
1585		cfset_session_del(req);
1586		kfree(req);
1587		file->private_data = NULL;
1588		ret = 0;
1589	}
1590	return ret;
1591}
1592
1593static long cfset_ioctl_start(unsigned long arg, struct file *file)
1594{
1595	struct s390_ctrset_start __user *ustart;
1596	struct s390_ctrset_start start;
1597	struct cfset_request *preq;
1598	void __user *umask;
1599	unsigned int len;
1600	int ret = 0;
1601	size_t need;
1602
1603	if (file->private_data)
1604		return -EBUSY;
1605	ustart = (struct s390_ctrset_start __user *)arg;
1606	if (copy_from_user(&start, ustart, sizeof(start)))
1607		return -EFAULT;
1608	if (start.version != S390_HWCTR_START_VERSION)
1609		return -EINVAL;
1610	if (start.counter_sets & ~(cpumf_ctr_ctl[CPUMF_CTR_SET_BASIC] |
1611				   cpumf_ctr_ctl[CPUMF_CTR_SET_USER] |
1612				   cpumf_ctr_ctl[CPUMF_CTR_SET_CRYPTO] |
1613				   cpumf_ctr_ctl[CPUMF_CTR_SET_EXT] |
1614				   cpumf_ctr_ctl[CPUMF_CTR_SET_MT_DIAG]))
1615		return -EINVAL;		/* Invalid counter set */
1616	if (!start.counter_sets)
1617		return -EINVAL;		/* No counter set at all? */
1618
1619	preq = kzalloc(sizeof(*preq), GFP_KERNEL);
1620	if (!preq)
1621		return -ENOMEM;
1622	cpumask_clear(&preq->mask);
1623	len = min_t(u64, start.cpumask_len, cpumask_size());
1624	umask = (void __user *)start.cpumask;
1625	if (copy_from_user(&preq->mask, umask, len)) {
1626		kfree(preq);
1627		return -EFAULT;
1628	}
1629	if (cpumask_empty(&preq->mask)) {
1630		kfree(preq);
1631		return -EINVAL;
1632	}
1633	need = cfset_needspace(start.counter_sets);
1634	if (put_user(need, &ustart->data_bytes)) {
1635		kfree(preq);
1636		return -EFAULT;
1637	}
1638	preq->ctrset = start.counter_sets;
1639	ret = cfset_all_start(preq);
1640	if (!ret) {
1641		cfset_session_add(preq);
1642		file->private_data = preq;
1643	} else {
1644		kfree(preq);
1645	}
1646	return ret;
1647}
1648
1649/* Entry point to the /dev/hwctr device interface.
1650 * The ioctl system call supports three subcommands:
1651 * S390_HWCTR_START: Start the specified counter sets on a CPU list. The
1652 *    counter set keeps running until explicitly stopped. Returns the number
1653 *    of bytes needed to store the counter values. If another S390_HWCTR_START
1654 *    ioctl subcommand is called without a previous S390_HWCTR_STOP stop
1655 *    command on the same file descriptor, -EBUSY is returned.
1656 * S390_HWCTR_READ: Read the counter set values from specified CPU list given
1657 *    with the S390_HWCTR_START command.
1658 * S390_HWCTR_STOP: Stops the counter sets on the CPU list given with the
1659 *    previous S390_HWCTR_START subcommand.
1660 */
1661static long cfset_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1662{
1663	int ret;
1664
1665	cpus_read_lock();
1666	mutex_lock(&cfset_ctrset_mutex);
1667	switch (cmd) {
1668	case S390_HWCTR_START:
1669		ret = cfset_ioctl_start(arg, file);
1670		break;
1671	case S390_HWCTR_STOP:
1672		ret = cfset_ioctl_stop(file);
1673		break;
1674	case S390_HWCTR_READ:
1675		ret = cfset_ioctl_read(arg, file->private_data);
1676		break;
1677	default:
1678		ret = -ENOTTY;
1679		break;
1680	}
1681	mutex_unlock(&cfset_ctrset_mutex);
1682	cpus_read_unlock();
1683	return ret;
1684}
1685
1686static const struct file_operations cfset_fops = {
1687	.owner = THIS_MODULE,
1688	.open = cfset_open,
1689	.release = cfset_release,
1690	.unlocked_ioctl	= cfset_ioctl,
1691};
1692
1693static struct miscdevice cfset_dev = {
1694	.name	= S390_HWCTR_DEVICE,
1695	.minor	= MISC_DYNAMIC_MINOR,
1696	.fops	= &cfset_fops,
1697	.mode	= 0666,
1698};
1699
1700/* Hotplug add of a CPU. Scan through all active processes and add
1701 * that CPU to the list of CPUs supplied with ioctl(..., START, ...).
1702 */
1703static int cfset_online_cpu(unsigned int cpu)
1704{
1705	struct cfset_call_on_cpu_parm p;
1706	struct cfset_request *rp;
1707
1708	if (!list_empty(&cfset_session.head)) {
1709		list_for_each_entry(rp, &cfset_session.head, node) {
1710			p.sets = rp->ctrset;
1711			cfset_ioctl_on(&p);
1712			cpumask_set_cpu(cpu, &rp->mask);
1713		}
1714	}
1715	return 0;
1716}
1717
1718/* Hotplug remove of a CPU. Scan through all active processes and clear
1719 * that CPU from the list of CPUs supplied with ioctl(..., START, ...).
1720 * Adjust reference counts.
1721 */
1722static int cfset_offline_cpu(unsigned int cpu)
1723{
1724	struct cfset_call_on_cpu_parm p;
1725	struct cfset_request *rp;
1726
1727	if (!list_empty(&cfset_session.head)) {
1728		list_for_each_entry(rp, &cfset_session.head, node) {
1729			p.sets = rp->ctrset;
1730			cfset_ioctl_off(&p);
1731			cpumask_clear_cpu(cpu, &rp->mask);
1732		}
1733	}
1734	return 0;
1735}
1736
1737static void cfdiag_read(struct perf_event *event)
1738{
1739}
1740
1741static int get_authctrsets(void)
1742{
1743	unsigned long auth = 0;
1744	enum cpumf_ctr_set i;
1745
1746	for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
1747		if (cpumf_ctr_info.auth_ctl & cpumf_ctr_ctl[i])
1748			auth |= cpumf_ctr_ctl[i];
1749	}
1750	return auth;
1751}
1752
1753/* Setup the event. Test for authorized counter sets and only include counter
1754 * sets which are authorized at the time of the setup. Including unauthorized
1755 * counter sets result in specification exception (and panic).
1756 */
1757static int cfdiag_event_init2(struct perf_event *event)
1758{
1759	struct perf_event_attr *attr = &event->attr;
1760	int err = 0;
1761
1762	/* Set sample_period to indicate sampling */
1763	event->hw.config = attr->config;
1764	event->hw.sample_period = attr->sample_period;
1765	local64_set(&event->hw.period_left, event->hw.sample_period);
1766	local64_set(&event->count, 0);
1767	event->hw.last_period = event->hw.sample_period;
1768
1769	/* Add all authorized counter sets to config_base. The
1770	 * the hardware init function is either called per-cpu or just once
1771	 * for all CPUS (event->cpu == -1).  This depends on the whether
1772	 * counting is started for all CPUs or on a per workload base where
1773	 * the perf event moves from one CPU to another CPU.
1774	 * Checking the authorization on any CPU is fine as the hardware
1775	 * applies the same authorization settings to all CPUs.
1776	 */
1777	event->hw.config_base = get_authctrsets();
1778
1779	/* No authorized counter sets, nothing to count/sample */
1780	if (!event->hw.config_base)
1781		err = -EINVAL;
1782
1783	return err;
1784}
1785
1786static int cfdiag_event_init(struct perf_event *event)
1787{
1788	struct perf_event_attr *attr = &event->attr;
1789	int err = -ENOENT;
1790
1791	if (event->attr.config != PERF_EVENT_CPUM_CF_DIAG ||
1792	    event->attr.type != event->pmu->type)
1793		goto out;
1794
1795	/* Raw events are used to access counters directly,
1796	 * hence do not permit excludes.
1797	 * This event is useless without PERF_SAMPLE_RAW to return counter set
1798	 * values as raw data.
1799	 */
1800	if (attr->exclude_kernel || attr->exclude_user || attr->exclude_hv ||
1801	    !(attr->sample_type & (PERF_SAMPLE_CPU | PERF_SAMPLE_RAW))) {
1802		err = -EOPNOTSUPP;
1803		goto out;
1804	}
1805
1806	/* Initialize for using the CPU-measurement counter facility */
1807	if (cpum_cf_alloc(event->cpu))
1808		return -ENOMEM;
1809	event->destroy = hw_perf_event_destroy;
1810
1811	err = cfdiag_event_init2(event);
1812out:
1813	return err;
1814}
1815
1816/* Create cf_diag/events/CF_DIAG event sysfs file. This counter is used
1817 * to collect the complete counter sets for a scheduled process. Target
1818 * are complete counter sets attached as raw data to the artificial event.
1819 * This results in complete counter sets available when a process is
1820 * scheduled. Contains the delta of every counter while the process was
1821 * running.
1822 */
1823CPUMF_EVENT_ATTR(CF_DIAG, CF_DIAG, PERF_EVENT_CPUM_CF_DIAG);
1824
1825static struct attribute *cfdiag_events_attr[] = {
1826	CPUMF_EVENT_PTR(CF_DIAG, CF_DIAG),
1827	NULL,
1828};
1829
1830PMU_FORMAT_ATTR(event, "config:0-63");
1831
1832static struct attribute *cfdiag_format_attr[] = {
1833	&format_attr_event.attr,
1834	NULL,
1835};
1836
1837static struct attribute_group cfdiag_events_group = {
1838	.name = "events",
1839	.attrs = cfdiag_events_attr,
1840};
1841static struct attribute_group cfdiag_format_group = {
1842	.name = "format",
1843	.attrs = cfdiag_format_attr,
1844};
1845static const struct attribute_group *cfdiag_attr_groups[] = {
1846	&cfdiag_events_group,
1847	&cfdiag_format_group,
1848	NULL,
1849};
1850
1851/* Performance monitoring unit for event CF_DIAG. Since this event
1852 * is also started and stopped via the perf_event_open() system call, use
1853 * the same event enable/disable call back functions. They do not
1854 * have a pointer to the perf_event structure as first parameter.
1855 *
1856 * The functions XXX_add, XXX_del, XXX_start and XXX_stop are also common.
1857 * Reuse them and distinguish the event (always first parameter) via
1858 * 'config' member.
1859 */
1860static struct pmu cf_diag = {
1861	.task_ctx_nr  = perf_sw_context,
1862	.event_init   = cfdiag_event_init,
1863	.pmu_enable   = cpumf_pmu_enable,
1864	.pmu_disable  = cpumf_pmu_disable,
1865	.add	      = cpumf_pmu_add,
1866	.del	      = cpumf_pmu_del,
1867	.start	      = cpumf_pmu_start,
1868	.stop	      = cpumf_pmu_stop,
1869	.read	      = cfdiag_read,
1870
1871	.attr_groups  = cfdiag_attr_groups
1872};
1873
1874/* Calculate memory needed to store all counter sets together with header and
1875 * trailer data. This is independent of the counter set authorization which
1876 * can vary depending on the configuration.
1877 */
1878static size_t cfdiag_maxsize(struct cpumf_ctr_info *info)
1879{
1880	size_t max_size = sizeof(struct cf_trailer_entry);
1881	enum cpumf_ctr_set i;
1882
1883	for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
1884		size_t size = cpum_cf_read_setsize(i);
1885
1886		if (size)
1887			max_size += size * sizeof(u64) +
1888				    sizeof(struct cf_ctrset_entry);
1889	}
1890	return max_size;
1891}
1892
1893/* Get the CPU speed, try sampling facility first and CPU attributes second. */
1894static void cfdiag_get_cpu_speed(void)
1895{
1896	unsigned long mhz;
1897
1898	if (cpum_sf_avail()) {			/* Sampling facility first */
1899		struct hws_qsi_info_block si;
1900
1901		memset(&si, 0, sizeof(si));
1902		if (!qsi(&si)) {
1903			cfdiag_cpu_speed = si.cpu_speed;
1904			return;
1905		}
1906	}
1907
1908	/* Fallback: CPU speed extract static part. Used in case
1909	 * CPU Measurement Sampling Facility is turned off.
1910	 */
1911	mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
1912	if (mhz != -1UL)
1913		cfdiag_cpu_speed = mhz & 0xffffffff;
1914}
1915
1916static int cfset_init(void)
1917{
1918	size_t need;
1919	int rc;
1920
1921	cfdiag_get_cpu_speed();
1922	/* Make sure the counter set data fits into predefined buffer. */
1923	need = cfdiag_maxsize(&cpumf_ctr_info);
1924	if (need > sizeof(((struct cpu_cf_events *)0)->start)) {
1925		pr_err("Insufficient memory for PMU(cpum_cf_diag) need=%zu\n",
1926		       need);
1927		return -ENOMEM;
1928	}
1929
1930	rc = misc_register(&cfset_dev);
1931	if (rc) {
1932		pr_err("Registration of /dev/%s failed rc=%i\n",
1933		       cfset_dev.name, rc);
1934		goto out;
1935	}
1936
1937	rc = perf_pmu_register(&cf_diag, "cpum_cf_diag", -1);
1938	if (rc) {
1939		misc_deregister(&cfset_dev);
1940		pr_err("Registration of PMU(cpum_cf_diag) failed with rc=%i\n",
1941		       rc);
1942	}
1943out:
1944	return rc;
1945}
1946
1947device_initcall(cpumf_pmu_init);