1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Performance event support for s390x - CPU-measurement Counter Sets
4 *
5 * Copyright IBM Corp. 2019, 2021
6 * Author(s): Hendrik Brueckner <brueckner@linux.ibm.com>
7 * Thomas Richer <tmricht@linux.ibm.com>
8 */
9 #define KMSG_COMPONENT "cpum_cf_diag"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11
12 #include <linux/kernel.h>
13 #include <linux/kernel_stat.h>
14 #include <linux/percpu.h>
15 #include <linux/notifier.h>
16 #include <linux/init.h>
17 #include <linux/export.h>
18 #include <linux/slab.h>
19 #include <linux/processor.h>
20 #include <linux/miscdevice.h>
21 #include <linux/mutex.h>
22
23 #include <asm/ctl_reg.h>
24 #include <asm/irq.h>
25 #include <asm/cpu_mcf.h>
26 #include <asm/timex.h>
27 #include <asm/debug.h>
28
29 #include <asm/hwctrset.h>
30
31 #define CF_DIAG_CTRSET_DEF 0xfeef /* Counter set header mark */
32 /* interval in seconds */
33 static unsigned int cf_diag_cpu_speed;
34 static debug_info_t *cf_diag_dbg;
35
36 struct cf_diag_csd { /* Counter set data per CPU */
37 size_t used; /* Bytes used in data/start */
38 unsigned char start[PAGE_SIZE]; /* Counter set at event start */
39 unsigned char data[PAGE_SIZE]; /* Counter set at event delete */
40 unsigned int sets; /* # Counter set saved in data */
41 };
42 static DEFINE_PER_CPU(struct cf_diag_csd, cf_diag_csd);
43
44 /* Counter sets are stored as data stream in a page sized memory buffer and
45 * exported to user space via raw data attached to the event sample data.
46 * Each counter set starts with an eight byte header consisting of:
47 * - a two byte eye catcher (0xfeef)
48 * - a one byte counter set number
49 * - a two byte counter set size (indicates the number of counters in this set)
50 * - a three byte reserved value (must be zero) to make the header the same
51 * size as a counter value.
52 * All counter values are eight byte in size.
53 *
54 * All counter sets are followed by a 64 byte trailer.
55 * The trailer consists of a:
56 * - flag field indicating valid fields when corresponding bit set
57 * - the counter facility first and second version number
58 * - the CPU speed if nonzero
59 * - the time stamp the counter sets have been collected
60 * - the time of day (TOD) base value
61 * - the machine type.
62 *
63 * The counter sets are saved when the process is prepared to be executed on a
64 * CPU and saved again when the process is going to be removed from a CPU.
65 * The difference of both counter sets are calculated and stored in the event
66 * sample data area.
67 */
68
69 struct cf_ctrset_entry { /* CPU-M CF counter set entry (8 byte) */
70 unsigned int def:16; /* 0-15 Data Entry Format */
71 unsigned int set:16; /* 16-31 Counter set identifier */
72 unsigned int ctr:16; /* 32-47 Number of stored counters */
73 unsigned int res1:16; /* 48-63 Reserved */
74 };
75
76 struct cf_trailer_entry { /* CPU-M CF_DIAG trailer (64 byte) */
77 /* 0 - 7 */
78 union {
79 struct {
80 unsigned int clock_base:1; /* TOD clock base set */
81 unsigned int speed:1; /* CPU speed set */
82 /* Measurement alerts */
83 unsigned int mtda:1; /* Loss of MT ctr. data alert */
84 unsigned int caca:1; /* Counter auth. change alert */
85 unsigned int lcda:1; /* Loss of counter data alert */
86 };
87 unsigned long flags; /* 0-63 All indicators */
88 };
89 /* 8 - 15 */
90 unsigned int cfvn:16; /* 64-79 Ctr First Version */
91 unsigned int csvn:16; /* 80-95 Ctr Second Version */
92 unsigned int cpu_speed:32; /* 96-127 CPU speed */
93 /* 16 - 23 */
94 unsigned long timestamp; /* 128-191 Timestamp (TOD) */
95 /* 24 - 55 */
96 union {
97 struct {
98 unsigned long progusage1;
99 unsigned long progusage2;
100 unsigned long progusage3;
101 unsigned long tod_base;
102 };
103 unsigned long progusage[4];
104 };
105 /* 56 - 63 */
106 unsigned int mach_type:16; /* Machine type */
107 unsigned int res1:16; /* Reserved */
108 unsigned int res2:32; /* Reserved */
109 };
110
111 /* Create the trailer data at the end of a page. */
cf_diag_trailer(struct cf_trailer_entry * te)112 static void cf_diag_trailer(struct cf_trailer_entry *te)
113 {
114 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
115 struct cpuid cpuid;
116
117 te->cfvn = cpuhw->info.cfvn; /* Counter version numbers */
118 te->csvn = cpuhw->info.csvn;
119
120 get_cpu_id(&cpuid); /* Machine type */
121 te->mach_type = cpuid.machine;
122 te->cpu_speed = cf_diag_cpu_speed;
123 if (te->cpu_speed)
124 te->speed = 1;
125 te->clock_base = 1; /* Save clock base */
126 te->tod_base = tod_clock_base.tod;
127 te->timestamp = get_tod_clock_fast();
128 }
129
130 /*
131 * Change the CPUMF state to active.
132 * Enable and activate the CPU-counter sets according
133 * to the per-cpu control state.
134 */
cf_diag_enable(struct pmu * pmu)135 static void cf_diag_enable(struct pmu *pmu)
136 {
137 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
138 int err;
139
140 debug_sprintf_event(cf_diag_dbg, 5,
141 "%s pmu %p cpu %d flags %#x state %#llx\n",
142 __func__, pmu, smp_processor_id(), cpuhw->flags,
143 cpuhw->state);
144 if (cpuhw->flags & PMU_F_ENABLED)
145 return;
146
147 err = lcctl(cpuhw->state);
148 if (err) {
149 pr_err("Enabling the performance measuring unit "
150 "failed with rc=%x\n", err);
151 return;
152 }
153 cpuhw->flags |= PMU_F_ENABLED;
154 }
155
156 /*
157 * Change the CPUMF state to inactive.
158 * Disable and enable (inactive) the CPU-counter sets according
159 * to the per-cpu control state.
160 */
cf_diag_disable(struct pmu * pmu)161 static void cf_diag_disable(struct pmu *pmu)
162 {
163 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
164 u64 inactive;
165 int err;
166
167 debug_sprintf_event(cf_diag_dbg, 5,
168 "%s pmu %p cpu %d flags %#x state %#llx\n",
169 __func__, pmu, smp_processor_id(), cpuhw->flags,
170 cpuhw->state);
171 if (!(cpuhw->flags & PMU_F_ENABLED))
172 return;
173
174 inactive = cpuhw->state & ~((1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1);
175 err = lcctl(inactive);
176 if (err) {
177 pr_err("Disabling the performance measuring unit "
178 "failed with rc=%x\n", err);
179 return;
180 }
181 cpuhw->flags &= ~PMU_F_ENABLED;
182 }
183
184 /* Number of perf events counting hardware events */
185 static atomic_t cf_diag_events = ATOMIC_INIT(0);
186 /* Used to avoid races in calling reserve/release_cpumf_hardware */
187 static DEFINE_MUTEX(cf_diag_reserve_mutex);
188
189 /* Release the PMU if event is the last perf event */
cf_diag_perf_event_destroy(struct perf_event * event)190 static void cf_diag_perf_event_destroy(struct perf_event *event)
191 {
192 debug_sprintf_event(cf_diag_dbg, 5,
193 "%s event %p cpu %d cf_diag_events %d\n",
194 __func__, event, smp_processor_id(),
195 atomic_read(&cf_diag_events));
196 if (atomic_dec_return(&cf_diag_events) == 0)
197 __kernel_cpumcf_end();
198 }
199
get_authctrsets(void)200 static int get_authctrsets(void)
201 {
202 struct cpu_cf_events *cpuhw;
203 unsigned long auth = 0;
204 enum cpumf_ctr_set i;
205
206 cpuhw = &get_cpu_var(cpu_cf_events);
207 for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
208 if (cpuhw->info.auth_ctl & cpumf_ctr_ctl[i])
209 auth |= cpumf_ctr_ctl[i];
210 }
211 put_cpu_var(cpu_cf_events);
212 return auth;
213 }
214
215 /* Setup the event. Test for authorized counter sets and only include counter
216 * sets which are authorized at the time of the setup. Including unauthorized
217 * counter sets result in specification exception (and panic).
218 */
__hw_perf_event_init(struct perf_event * event)219 static int __hw_perf_event_init(struct perf_event *event)
220 {
221 struct perf_event_attr *attr = &event->attr;
222 int err = 0;
223
224 debug_sprintf_event(cf_diag_dbg, 5, "%s event %p cpu %d\n", __func__,
225 event, event->cpu);
226
227 event->hw.config = attr->config;
228
229 /* Add all authorized counter sets to config_base. The
230 * the hardware init function is either called per-cpu or just once
231 * for all CPUS (event->cpu == -1). This depends on the whether
232 * counting is started for all CPUs or on a per workload base where
233 * the perf event moves from one CPU to another CPU.
234 * Checking the authorization on any CPU is fine as the hardware
235 * applies the same authorization settings to all CPUs.
236 */
237 event->hw.config_base = get_authctrsets();
238
239 /* No authorized counter sets, nothing to count/sample */
240 if (!event->hw.config_base) {
241 err = -EINVAL;
242 goto out;
243 }
244
245 /* Set sample_period to indicate sampling */
246 event->hw.sample_period = attr->sample_period;
247 local64_set(&event->hw.period_left, event->hw.sample_period);
248 event->hw.last_period = event->hw.sample_period;
249 out:
250 debug_sprintf_event(cf_diag_dbg, 5, "%s err %d config_base %#lx\n",
251 __func__, err, event->hw.config_base);
252 return err;
253 }
254
255 /* Return 0 if the CPU-measurement counter facility is currently free
256 * and an error otherwise.
257 */
cf_diag_perf_event_inuse(void)258 static int cf_diag_perf_event_inuse(void)
259 {
260 int err = 0;
261
262 if (!atomic_inc_not_zero(&cf_diag_events)) {
263 mutex_lock(&cf_diag_reserve_mutex);
264 if (atomic_read(&cf_diag_events) == 0 &&
265 __kernel_cpumcf_begin())
266 err = -EBUSY;
267 else
268 err = atomic_inc_return(&cf_diag_events);
269 mutex_unlock(&cf_diag_reserve_mutex);
270 }
271 return err;
272 }
273
cf_diag_event_init(struct perf_event * event)274 static int cf_diag_event_init(struct perf_event *event)
275 {
276 struct perf_event_attr *attr = &event->attr;
277 int err = -ENOENT;
278
279 debug_sprintf_event(cf_diag_dbg, 5,
280 "%s event %p cpu %d config %#llx type:%u "
281 "sample_type %#llx cf_diag_events %d\n", __func__,
282 event, event->cpu, attr->config, event->pmu->type,
283 attr->sample_type, atomic_read(&cf_diag_events));
284
285 if (event->attr.config != PERF_EVENT_CPUM_CF_DIAG ||
286 event->attr.type != event->pmu->type)
287 goto out;
288
289 /* Raw events are used to access counters directly,
290 * hence do not permit excludes.
291 * This event is usesless without PERF_SAMPLE_RAW to return counter set
292 * values as raw data.
293 */
294 if (attr->exclude_kernel || attr->exclude_user || attr->exclude_hv ||
295 !(attr->sample_type & (PERF_SAMPLE_CPU | PERF_SAMPLE_RAW))) {
296 err = -EOPNOTSUPP;
297 goto out;
298 }
299
300 /* Initialize for using the CPU-measurement counter facility */
301 err = cf_diag_perf_event_inuse();
302 if (err < 0)
303 goto out;
304 event->destroy = cf_diag_perf_event_destroy;
305
306 err = __hw_perf_event_init(event);
307 if (unlikely(err))
308 event->destroy(event);
309 out:
310 debug_sprintf_event(cf_diag_dbg, 5, "%s err %d\n", __func__, err);
311 return err;
312 }
313
cf_diag_read(struct perf_event * event)314 static void cf_diag_read(struct perf_event *event)
315 {
316 debug_sprintf_event(cf_diag_dbg, 5, "%s event %p\n", __func__, event);
317 }
318
319 /* Calculate memory needed to store all counter sets together with header and
320 * trailer data. This is independend of the counter set authorization which
321 * can vary depending on the configuration.
322 */
cf_diag_ctrset_maxsize(struct cpumf_ctr_info * info)323 static size_t cf_diag_ctrset_maxsize(struct cpumf_ctr_info *info)
324 {
325 size_t max_size = sizeof(struct cf_trailer_entry);
326 enum cpumf_ctr_set i;
327
328 for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
329 size_t size = cpum_cf_ctrset_size(i, info);
330
331 if (size)
332 max_size += size * sizeof(u64) +
333 sizeof(struct cf_ctrset_entry);
334 }
335 debug_sprintf_event(cf_diag_dbg, 5, "%s max_size %zu\n", __func__,
336 max_size);
337
338 return max_size;
339 }
340
341 /* Read a counter set. The counter set number determines which counter set and
342 * the CPUM-CF first and second version number determine the number of
343 * available counters in this counter set.
344 * Each counter set starts with header containing the counter set number and
345 * the number of 8 byte counters.
346 *
347 * The functions returns the number of bytes occupied by this counter set
348 * including the header.
349 * If there is no counter in the counter set, this counter set is useless and
350 * zero is returned on this case.
351 */
cf_diag_getctrset(struct cf_ctrset_entry * ctrdata,int ctrset,size_t room)352 static size_t cf_diag_getctrset(struct cf_ctrset_entry *ctrdata, int ctrset,
353 size_t room)
354 {
355 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
356 size_t ctrset_size, need = 0;
357 int rc = 3; /* Assume write failure */
358
359 ctrdata->def = CF_DIAG_CTRSET_DEF;
360 ctrdata->set = ctrset;
361 ctrdata->res1 = 0;
362 ctrset_size = cpum_cf_ctrset_size(ctrset, &cpuhw->info);
363
364 if (ctrset_size) { /* Save data */
365 need = ctrset_size * sizeof(u64) + sizeof(*ctrdata);
366 if (need <= room)
367 rc = ctr_stcctm(ctrset, ctrset_size,
368 (u64 *)(ctrdata + 1));
369 if (rc != 3)
370 ctrdata->ctr = ctrset_size;
371 else
372 need = 0;
373 }
374
375 debug_sprintf_event(cf_diag_dbg, 6,
376 "%s ctrset %d ctrset_size %zu cfvn %d csvn %d"
377 " need %zd rc %d\n",
378 __func__, ctrset, ctrset_size, cpuhw->info.cfvn,
379 cpuhw->info.csvn, need, rc);
380 return need;
381 }
382
383 /* Read out all counter sets and save them in the provided data buffer.
384 * The last 64 byte host an artificial trailer entry.
385 */
cf_diag_getctr(void * data,size_t sz,unsigned long auth)386 static size_t cf_diag_getctr(void *data, size_t sz, unsigned long auth)
387 {
388 struct cf_trailer_entry *trailer;
389 size_t offset = 0, done;
390 int i;
391
392 memset(data, 0, sz);
393 sz -= sizeof(*trailer); /* Always room for trailer */
394 for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
395 struct cf_ctrset_entry *ctrdata = data + offset;
396
397 if (!(auth & cpumf_ctr_ctl[i]))
398 continue; /* Counter set not authorized */
399
400 done = cf_diag_getctrset(ctrdata, i, sz - offset);
401 offset += done;
402 debug_sprintf_event(cf_diag_dbg, 6,
403 "%s ctrset %d offset %zu done %zu\n",
404 __func__, i, offset, done);
405 }
406 trailer = data + offset;
407 cf_diag_trailer(trailer);
408 return offset + sizeof(*trailer);
409 }
410
411 /* Calculate the difference for each counter in a counter set. */
cf_diag_diffctrset(u64 * pstart,u64 * pstop,int counters)412 static void cf_diag_diffctrset(u64 *pstart, u64 *pstop, int counters)
413 {
414 for (; --counters >= 0; ++pstart, ++pstop)
415 if (*pstop >= *pstart)
416 *pstop -= *pstart;
417 else
418 *pstop = *pstart - *pstop;
419 }
420
421 /* Scan the counter sets and calculate the difference of each counter
422 * in each set. The result is the increment of each counter during the
423 * period the counter set has been activated.
424 *
425 * Return true on success.
426 */
cf_diag_diffctr(struct cf_diag_csd * csd,unsigned long auth)427 static int cf_diag_diffctr(struct cf_diag_csd *csd, unsigned long auth)
428 {
429 struct cf_trailer_entry *trailer_start, *trailer_stop;
430 struct cf_ctrset_entry *ctrstart, *ctrstop;
431 size_t offset = 0;
432
433 auth &= (1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1;
434 do {
435 ctrstart = (struct cf_ctrset_entry *)(csd->start + offset);
436 ctrstop = (struct cf_ctrset_entry *)(csd->data + offset);
437
438 if (memcmp(ctrstop, ctrstart, sizeof(*ctrstop))) {
439 pr_err("cpum_cf_diag counter set compare error "
440 "in set %i\n", ctrstart->set);
441 return 0;
442 }
443 auth &= ~cpumf_ctr_ctl[ctrstart->set];
444 if (ctrstart->def == CF_DIAG_CTRSET_DEF) {
445 cf_diag_diffctrset((u64 *)(ctrstart + 1),
446 (u64 *)(ctrstop + 1), ctrstart->ctr);
447 offset += ctrstart->ctr * sizeof(u64) +
448 sizeof(*ctrstart);
449 }
450 debug_sprintf_event(cf_diag_dbg, 6,
451 "%s set %d ctr %d offset %zu auth %lx\n",
452 __func__, ctrstart->set, ctrstart->ctr,
453 offset, auth);
454 } while (ctrstart->def && auth);
455
456 /* Save time_stamp from start of event in stop's trailer */
457 trailer_start = (struct cf_trailer_entry *)(csd->start + offset);
458 trailer_stop = (struct cf_trailer_entry *)(csd->data + offset);
459 trailer_stop->progusage[0] = trailer_start->timestamp;
460
461 return 1;
462 }
463
464 /* Create perf event sample with the counter sets as raw data. The sample
465 * is then pushed to the event subsystem and the function checks for
466 * possible event overflows. If an event overflow occurs, the PMU is
467 * stopped.
468 *
469 * Return non-zero if an event overflow occurred.
470 */
cf_diag_push_sample(struct perf_event * event,struct cf_diag_csd * csd)471 static int cf_diag_push_sample(struct perf_event *event,
472 struct cf_diag_csd *csd)
473 {
474 struct perf_sample_data data;
475 struct perf_raw_record raw;
476 struct pt_regs regs;
477 int overflow;
478
479 /* Setup perf sample */
480 perf_sample_data_init(&data, 0, event->hw.last_period);
481 memset(®s, 0, sizeof(regs));
482 memset(&raw, 0, sizeof(raw));
483
484 if (event->attr.sample_type & PERF_SAMPLE_CPU)
485 data.cpu_entry.cpu = event->cpu;
486 if (event->attr.sample_type & PERF_SAMPLE_RAW) {
487 raw.frag.size = csd->used;
488 raw.frag.data = csd->data;
489 raw.size = csd->used;
490 data.raw = &raw;
491 }
492
493 overflow = perf_event_overflow(event, &data, ®s);
494 debug_sprintf_event(cf_diag_dbg, 6,
495 "%s event %p cpu %d sample_type %#llx raw %d "
496 "ov %d\n", __func__, event, event->cpu,
497 event->attr.sample_type, raw.size, overflow);
498 if (overflow)
499 event->pmu->stop(event, 0);
500
501 perf_event_update_userpage(event);
502 return overflow;
503 }
504
cf_diag_start(struct perf_event * event,int flags)505 static void cf_diag_start(struct perf_event *event, int flags)
506 {
507 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
508 struct cf_diag_csd *csd = this_cpu_ptr(&cf_diag_csd);
509 struct hw_perf_event *hwc = &event->hw;
510
511 debug_sprintf_event(cf_diag_dbg, 5,
512 "%s event %p cpu %d flags %#x hwc-state %#x\n",
513 __func__, event, event->cpu, flags, hwc->state);
514 if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
515 return;
516
517 /* (Re-)enable and activate all counter sets */
518 lcctl(0); /* Reset counter sets */
519 hwc->state = 0;
520 ctr_set_multiple_enable(&cpuhw->state, hwc->config_base);
521 lcctl(cpuhw->state); /* Enable counter sets */
522 csd->used = cf_diag_getctr(csd->start, sizeof(csd->start),
523 event->hw.config_base);
524 ctr_set_multiple_start(&cpuhw->state, hwc->config_base);
525 /* Function cf_diag_enable() starts the counter sets. */
526 }
527
cf_diag_stop(struct perf_event * event,int flags)528 static void cf_diag_stop(struct perf_event *event, int flags)
529 {
530 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
531 struct cf_diag_csd *csd = this_cpu_ptr(&cf_diag_csd);
532 struct hw_perf_event *hwc = &event->hw;
533
534 debug_sprintf_event(cf_diag_dbg, 5,
535 "%s event %p cpu %d flags %#x hwc-state %#x\n",
536 __func__, event, event->cpu, flags, hwc->state);
537
538 /* Deactivate all counter sets */
539 ctr_set_multiple_stop(&cpuhw->state, hwc->config_base);
540 local64_inc(&event->count);
541 csd->used = cf_diag_getctr(csd->data, sizeof(csd->data),
542 event->hw.config_base);
543 if (cf_diag_diffctr(csd, event->hw.config_base))
544 cf_diag_push_sample(event, csd);
545 hwc->state |= PERF_HES_STOPPED;
546 }
547
cf_diag_add(struct perf_event * event,int flags)548 static int cf_diag_add(struct perf_event *event, int flags)
549 {
550 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
551 int err = 0;
552
553 debug_sprintf_event(cf_diag_dbg, 5,
554 "%s event %p cpu %d flags %#x cpuhw %p\n",
555 __func__, event, event->cpu, flags, cpuhw);
556
557 if (cpuhw->flags & PMU_F_IN_USE) {
558 err = -EAGAIN;
559 goto out;
560 }
561
562 event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
563
564 cpuhw->flags |= PMU_F_IN_USE;
565 if (flags & PERF_EF_START)
566 cf_diag_start(event, PERF_EF_RELOAD);
567 out:
568 debug_sprintf_event(cf_diag_dbg, 5, "%s err %d\n", __func__, err);
569 return err;
570 }
571
cf_diag_del(struct perf_event * event,int flags)572 static void cf_diag_del(struct perf_event *event, int flags)
573 {
574 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
575
576 debug_sprintf_event(cf_diag_dbg, 5,
577 "%s event %p cpu %d flags %#x\n",
578 __func__, event, event->cpu, flags);
579
580 cf_diag_stop(event, PERF_EF_UPDATE);
581 ctr_set_multiple_stop(&cpuhw->state, event->hw.config_base);
582 ctr_set_multiple_disable(&cpuhw->state, event->hw.config_base);
583 cpuhw->flags &= ~PMU_F_IN_USE;
584 }
585
586 /* Default counter set events and format attribute groups */
587
588 CPUMF_EVENT_ATTR(CF_DIAG, CF_DIAG, PERF_EVENT_CPUM_CF_DIAG);
589
590 static struct attribute *cf_diag_events_attr[] = {
591 CPUMF_EVENT_PTR(CF_DIAG, CF_DIAG),
592 NULL,
593 };
594
595 PMU_FORMAT_ATTR(event, "config:0-63");
596
597 static struct attribute *cf_diag_format_attr[] = {
598 &format_attr_event.attr,
599 NULL,
600 };
601
602 static struct attribute_group cf_diag_events_group = {
603 .name = "events",
604 .attrs = cf_diag_events_attr,
605 };
606 static struct attribute_group cf_diag_format_group = {
607 .name = "format",
608 .attrs = cf_diag_format_attr,
609 };
610 static const struct attribute_group *cf_diag_attr_groups[] = {
611 &cf_diag_events_group,
612 &cf_diag_format_group,
613 NULL,
614 };
615
616 /* Performance monitoring unit for s390x */
617 static struct pmu cf_diag = {
618 .task_ctx_nr = perf_sw_context,
619 .pmu_enable = cf_diag_enable,
620 .pmu_disable = cf_diag_disable,
621 .event_init = cf_diag_event_init,
622 .add = cf_diag_add,
623 .del = cf_diag_del,
624 .start = cf_diag_start,
625 .stop = cf_diag_stop,
626 .read = cf_diag_read,
627
628 .attr_groups = cf_diag_attr_groups
629 };
630
631 /* Get the CPU speed, try sampling facility first and CPU attributes second. */
cf_diag_get_cpu_speed(void)632 static void cf_diag_get_cpu_speed(void)
633 {
634 if (cpum_sf_avail()) { /* Sampling facility first */
635 struct hws_qsi_info_block si;
636
637 memset(&si, 0, sizeof(si));
638 if (!qsi(&si)) {
639 cf_diag_cpu_speed = si.cpu_speed;
640 return;
641 }
642 }
643
644 if (test_facility(34)) { /* CPU speed extract static part */
645 unsigned long mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
646
647 if (mhz != -1UL)
648 cf_diag_cpu_speed = mhz & 0xffffffff;
649 }
650 }
651
652 /* Code to create device and file I/O operations */
653 static atomic_t ctrset_opencnt = ATOMIC_INIT(0); /* Excl. access */
654
cf_diag_open(struct inode * inode,struct file * file)655 static int cf_diag_open(struct inode *inode, struct file *file)
656 {
657 int err = 0;
658
659 if (!capable(CAP_SYS_ADMIN))
660 return -EPERM;
661 if (atomic_xchg(&ctrset_opencnt, 1))
662 return -EBUSY;
663
664 /* Avoid concurrent access with perf_event_open() system call */
665 mutex_lock(&cf_diag_reserve_mutex);
666 if (atomic_read(&cf_diag_events) || __kernel_cpumcf_begin())
667 err = -EBUSY;
668 mutex_unlock(&cf_diag_reserve_mutex);
669 if (err) {
670 atomic_set(&ctrset_opencnt, 0);
671 return err;
672 }
673 file->private_data = NULL;
674 debug_sprintf_event(cf_diag_dbg, 2, "%s\n", __func__);
675 /* nonseekable_open() never fails */
676 return nonseekable_open(inode, file);
677 }
678
679 /* Variables for ioctl() interface support */
680 static DEFINE_MUTEX(cf_diag_ctrset_mutex);
681 static struct cf_diag_ctrset {
682 unsigned long ctrset; /* Bit mask of counter set to read */
683 cpumask_t mask; /* CPU mask to read from */
684 } cf_diag_ctrset;
685
cf_diag_ctrset_clear(void)686 static void cf_diag_ctrset_clear(void)
687 {
688 cpumask_clear(&cf_diag_ctrset.mask);
689 cf_diag_ctrset.ctrset = 0;
690 }
691
cf_diag_release_cpu(void * p)692 static void cf_diag_release_cpu(void *p)
693 {
694 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
695
696 debug_sprintf_event(cf_diag_dbg, 3, "%s cpu %d\n", __func__,
697 smp_processor_id());
698 lcctl(0); /* Reset counter sets */
699 cpuhw->state = 0; /* Save state in CPU hardware state */
700 }
701
702 /* Release function is also called when application gets terminated without
703 * doing a proper ioctl(..., S390_HWCTR_STOP, ...) command.
704 * Since only one application is allowed to open the device, simple stop all
705 * CPU counter sets.
706 */
cf_diag_release(struct inode * inode,struct file * file)707 static int cf_diag_release(struct inode *inode, struct file *file)
708 {
709 on_each_cpu(cf_diag_release_cpu, NULL, 1);
710 cf_diag_ctrset_clear();
711 atomic_set(&ctrset_opencnt, 0);
712 __kernel_cpumcf_end();
713 debug_sprintf_event(cf_diag_dbg, 2, "%s\n", __func__);
714 return 0;
715 }
716
717 struct cf_diag_call_on_cpu_parm { /* Parm struct for smp_call_on_cpu */
718 unsigned int sets; /* Counter set bit mask */
719 atomic_t cpus_ack; /* # CPUs successfully executed func */
720 };
721
cf_diag_all_copy(unsigned long arg,cpumask_t * mask)722 static int cf_diag_all_copy(unsigned long arg, cpumask_t *mask)
723 {
724 struct s390_ctrset_read __user *ctrset_read;
725 unsigned int cpu, cpus, rc;
726 void __user *uptr;
727
728 ctrset_read = (struct s390_ctrset_read __user *)arg;
729 uptr = ctrset_read->data;
730 for_each_cpu(cpu, mask) {
731 struct cf_diag_csd *csd = per_cpu_ptr(&cf_diag_csd, cpu);
732 struct s390_ctrset_cpudata __user *ctrset_cpudata;
733
734 ctrset_cpudata = uptr;
735 debug_sprintf_event(cf_diag_dbg, 5, "%s cpu %d used %zd\n",
736 __func__, cpu, csd->used);
737 rc = put_user(cpu, &ctrset_cpudata->cpu_nr);
738 rc |= put_user(csd->sets, &ctrset_cpudata->no_sets);
739 rc |= copy_to_user(ctrset_cpudata->data, csd->data, csd->used);
740 if (rc)
741 return -EFAULT;
742 uptr += sizeof(struct s390_ctrset_cpudata) + csd->used;
743 cond_resched();
744 }
745 cpus = cpumask_weight(mask);
746 if (put_user(cpus, &ctrset_read->no_cpus))
747 return -EFAULT;
748 debug_sprintf_event(cf_diag_dbg, 5, "%s copied %ld\n",
749 __func__, uptr - (void __user *)ctrset_read->data);
750 return 0;
751 }
752
cf_diag_cpuset_read(struct s390_ctrset_setdata * p,int ctrset,int ctrset_size,size_t room)753 static size_t cf_diag_cpuset_read(struct s390_ctrset_setdata *p, int ctrset,
754 int ctrset_size, size_t room)
755 {
756 size_t need = 0;
757 int rc = -1;
758
759 need = sizeof(*p) + sizeof(u64) * ctrset_size;
760 debug_sprintf_event(cf_diag_dbg, 5,
761 "%s room %zd need %zd set %#x set_size %d\n",
762 __func__, room, need, ctrset, ctrset_size);
763 if (need <= room) {
764 p->set = cpumf_ctr_ctl[ctrset];
765 p->no_cnts = ctrset_size;
766 rc = ctr_stcctm(ctrset, ctrset_size, (u64 *)p->cv);
767 if (rc == 3) /* Nothing stored */
768 need = 0;
769 }
770 debug_sprintf_event(cf_diag_dbg, 5, "%s need %zd rc %d\n", __func__,
771 need, rc);
772 return need;
773 }
774
775 /* Read all counter sets. Since the perf_event_open() system call with
776 * event cpum_cf_diag/.../ is blocked when this interface is active, reuse
777 * the perf_event_open() data buffer to store the counter sets.
778 */
cf_diag_cpu_read(void * parm)779 static void cf_diag_cpu_read(void *parm)
780 {
781 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
782 struct cf_diag_csd *csd = this_cpu_ptr(&cf_diag_csd);
783 struct cf_diag_call_on_cpu_parm *p = parm;
784 int set, set_size;
785 size_t space;
786
787 debug_sprintf_event(cf_diag_dbg, 5,
788 "%s new %#x flags %#x state %#llx\n",
789 __func__, p->sets, cpuhw->flags,
790 cpuhw->state);
791 /* No data saved yet */
792 csd->used = 0;
793 csd->sets = 0;
794 memset(csd->data, 0, sizeof(csd->data));
795
796 /* Scan the counter sets */
797 for (set = CPUMF_CTR_SET_BASIC; set < CPUMF_CTR_SET_MAX; ++set) {
798 struct s390_ctrset_setdata *sp = (void *)csd->data + csd->used;
799
800 if (!(p->sets & cpumf_ctr_ctl[set]))
801 continue; /* Counter set not in list */
802 set_size = cpum_cf_ctrset_size(set, &cpuhw->info);
803 space = sizeof(csd->data) - csd->used;
804 space = cf_diag_cpuset_read(sp, set, set_size, space);
805 if (space) {
806 csd->used += space;
807 csd->sets += 1;
808 }
809 debug_sprintf_event(cf_diag_dbg, 5, "%s sp %px space %zd\n",
810 __func__, sp, space);
811 }
812 debug_sprintf_event(cf_diag_dbg, 5, "%s sets %d used %zd\n", __func__,
813 csd->sets, csd->used);
814 }
815
cf_diag_all_read(unsigned long arg)816 static int cf_diag_all_read(unsigned long arg)
817 {
818 struct cf_diag_call_on_cpu_parm p;
819 cpumask_var_t mask;
820 int rc;
821
822 debug_sprintf_event(cf_diag_dbg, 5, "%s\n", __func__);
823 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
824 return -ENOMEM;
825
826 p.sets = cf_diag_ctrset.ctrset;
827 cpumask_and(mask, &cf_diag_ctrset.mask, cpu_online_mask);
828 on_each_cpu_mask(mask, cf_diag_cpu_read, &p, 1);
829 rc = cf_diag_all_copy(arg, mask);
830 free_cpumask_var(mask);
831 debug_sprintf_event(cf_diag_dbg, 5, "%s rc %d\n", __func__, rc);
832 return rc;
833 }
834
835 /* Stop all counter sets via ioctl interface */
cf_diag_ioctl_off(void * parm)836 static void cf_diag_ioctl_off(void *parm)
837 {
838 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
839 struct cf_diag_call_on_cpu_parm *p = parm;
840 int rc;
841
842 debug_sprintf_event(cf_diag_dbg, 5,
843 "%s new %#x flags %#x state %#llx\n",
844 __func__, p->sets, cpuhw->flags,
845 cpuhw->state);
846
847 ctr_set_multiple_disable(&cpuhw->state, p->sets);
848 ctr_set_multiple_stop(&cpuhw->state, p->sets);
849 rc = lcctl(cpuhw->state); /* Stop counter sets */
850 if (!cpuhw->state)
851 cpuhw->flags &= ~PMU_F_IN_USE;
852 debug_sprintf_event(cf_diag_dbg, 5,
853 "%s rc %d flags %#x state %#llx\n", __func__,
854 rc, cpuhw->flags, cpuhw->state);
855 }
856
857 /* Start counter sets on particular CPU */
cf_diag_ioctl_on(void * parm)858 static void cf_diag_ioctl_on(void *parm)
859 {
860 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
861 struct cf_diag_call_on_cpu_parm *p = parm;
862 int rc;
863
864 debug_sprintf_event(cf_diag_dbg, 5,
865 "%s new %#x flags %#x state %#llx\n",
866 __func__, p->sets, cpuhw->flags,
867 cpuhw->state);
868
869 if (!(cpuhw->flags & PMU_F_IN_USE))
870 cpuhw->state = 0;
871 cpuhw->flags |= PMU_F_IN_USE;
872 rc = lcctl(cpuhw->state); /* Reset unused counter sets */
873 ctr_set_multiple_enable(&cpuhw->state, p->sets);
874 ctr_set_multiple_start(&cpuhw->state, p->sets);
875 rc |= lcctl(cpuhw->state); /* Start counter sets */
876 if (!rc)
877 atomic_inc(&p->cpus_ack);
878 debug_sprintf_event(cf_diag_dbg, 5, "%s rc %d state %#llx\n",
879 __func__, rc, cpuhw->state);
880 }
881
cf_diag_all_stop(void)882 static int cf_diag_all_stop(void)
883 {
884 struct cf_diag_call_on_cpu_parm p = {
885 .sets = cf_diag_ctrset.ctrset,
886 };
887 cpumask_var_t mask;
888
889 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
890 return -ENOMEM;
891 cpumask_and(mask, &cf_diag_ctrset.mask, cpu_online_mask);
892 on_each_cpu_mask(mask, cf_diag_ioctl_off, &p, 1);
893 free_cpumask_var(mask);
894 return 0;
895 }
896
cf_diag_all_start(void)897 static int cf_diag_all_start(void)
898 {
899 struct cf_diag_call_on_cpu_parm p = {
900 .sets = cf_diag_ctrset.ctrset,
901 .cpus_ack = ATOMIC_INIT(0),
902 };
903 cpumask_var_t mask;
904 int rc = 0;
905
906 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
907 return -ENOMEM;
908 cpumask_and(mask, &cf_diag_ctrset.mask, cpu_online_mask);
909 on_each_cpu_mask(mask, cf_diag_ioctl_on, &p, 1);
910 if (atomic_read(&p.cpus_ack) != cpumask_weight(mask)) {
911 on_each_cpu_mask(mask, cf_diag_ioctl_off, &p, 1);
912 rc = -EIO;
913 }
914 free_cpumask_var(mask);
915 return rc;
916 }
917
918 /* Return the maximum required space for all possible CPUs in case one
919 * CPU will be onlined during the START, READ, STOP cycles.
920 * To find out the size of the counter sets, any one CPU will do. They
921 * all have the same counter sets.
922 */
cf_diag_needspace(unsigned int sets)923 static size_t cf_diag_needspace(unsigned int sets)
924 {
925 struct cpu_cf_events *cpuhw = get_cpu_ptr(&cpu_cf_events);
926 size_t bytes = 0;
927 int i;
928
929 for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
930 if (!(sets & cpumf_ctr_ctl[i]))
931 continue;
932 bytes += cpum_cf_ctrset_size(i, &cpuhw->info) * sizeof(u64) +
933 sizeof(((struct s390_ctrset_setdata *)0)->set) +
934 sizeof(((struct s390_ctrset_setdata *)0)->no_cnts);
935 }
936 bytes = sizeof(((struct s390_ctrset_read *)0)->no_cpus) + nr_cpu_ids *
937 (bytes + sizeof(((struct s390_ctrset_cpudata *)0)->cpu_nr) +
938 sizeof(((struct s390_ctrset_cpudata *)0)->no_sets));
939 debug_sprintf_event(cf_diag_dbg, 5, "%s bytes %ld\n", __func__,
940 bytes);
941 put_cpu_ptr(&cpu_cf_events);
942 return bytes;
943 }
944
cf_diag_ioctl_read(unsigned long arg)945 static long cf_diag_ioctl_read(unsigned long arg)
946 {
947 struct s390_ctrset_read read;
948 int ret = 0;
949
950 debug_sprintf_event(cf_diag_dbg, 5, "%s\n", __func__);
951 if (copy_from_user(&read, (char __user *)arg, sizeof(read)))
952 return -EFAULT;
953 ret = cf_diag_all_read(arg);
954 debug_sprintf_event(cf_diag_dbg, 5, "%s ret %d\n", __func__, ret);
955 return ret;
956 }
957
cf_diag_ioctl_stop(void)958 static long cf_diag_ioctl_stop(void)
959 {
960 int ret;
961
962 debug_sprintf_event(cf_diag_dbg, 5, "%s\n", __func__);
963 ret = cf_diag_all_stop();
964 cf_diag_ctrset_clear();
965 debug_sprintf_event(cf_diag_dbg, 5, "%s ret %d\n", __func__, ret);
966 return ret;
967 }
968
cf_diag_ioctl_start(unsigned long arg)969 static long cf_diag_ioctl_start(unsigned long arg)
970 {
971 struct s390_ctrset_start __user *ustart;
972 struct s390_ctrset_start start;
973 void __user *umask;
974 unsigned int len;
975 int ret = 0;
976 size_t need;
977
978 if (cf_diag_ctrset.ctrset)
979 return -EBUSY;
980 ustart = (struct s390_ctrset_start __user *)arg;
981 if (copy_from_user(&start, ustart, sizeof(start)))
982 return -EFAULT;
983 if (start.version != S390_HWCTR_START_VERSION)
984 return -EINVAL;
985 if (start.counter_sets & ~(cpumf_ctr_ctl[CPUMF_CTR_SET_BASIC] |
986 cpumf_ctr_ctl[CPUMF_CTR_SET_USER] |
987 cpumf_ctr_ctl[CPUMF_CTR_SET_CRYPTO] |
988 cpumf_ctr_ctl[CPUMF_CTR_SET_EXT] |
989 cpumf_ctr_ctl[CPUMF_CTR_SET_MT_DIAG]))
990 return -EINVAL; /* Invalid counter set */
991 if (!start.counter_sets)
992 return -EINVAL; /* No counter set at all? */
993 cpumask_clear(&cf_diag_ctrset.mask);
994 len = min_t(u64, start.cpumask_len, cpumask_size());
995 umask = (void __user *)start.cpumask;
996 if (copy_from_user(&cf_diag_ctrset.mask, umask, len))
997 return -EFAULT;
998 if (cpumask_empty(&cf_diag_ctrset.mask))
999 return -EINVAL;
1000 need = cf_diag_needspace(start.counter_sets);
1001 if (put_user(need, &ustart->data_bytes))
1002 ret = -EFAULT;
1003 if (ret)
1004 goto out;
1005 cf_diag_ctrset.ctrset = start.counter_sets;
1006 ret = cf_diag_all_start();
1007 out:
1008 if (ret)
1009 cf_diag_ctrset_clear();
1010 debug_sprintf_event(cf_diag_dbg, 2, "%s sets %#lx need %ld ret %d\n",
1011 __func__, cf_diag_ctrset.ctrset, need, ret);
1012 return ret;
1013 }
1014
cf_diag_ioctl(struct file * file,unsigned int cmd,unsigned long arg)1015 static long cf_diag_ioctl(struct file *file, unsigned int cmd,
1016 unsigned long arg)
1017 {
1018 int ret;
1019
1020 debug_sprintf_event(cf_diag_dbg, 2, "%s cmd %#x arg %lx\n", __func__,
1021 cmd, arg);
1022 get_online_cpus();
1023 mutex_lock(&cf_diag_ctrset_mutex);
1024 switch (cmd) {
1025 case S390_HWCTR_START:
1026 ret = cf_diag_ioctl_start(arg);
1027 break;
1028 case S390_HWCTR_STOP:
1029 ret = cf_diag_ioctl_stop();
1030 break;
1031 case S390_HWCTR_READ:
1032 ret = cf_diag_ioctl_read(arg);
1033 break;
1034 default:
1035 ret = -ENOTTY;
1036 break;
1037 }
1038 mutex_unlock(&cf_diag_ctrset_mutex);
1039 put_online_cpus();
1040 debug_sprintf_event(cf_diag_dbg, 2, "%s ret %d\n", __func__, ret);
1041 return ret;
1042 }
1043
1044 static const struct file_operations cf_diag_fops = {
1045 .owner = THIS_MODULE,
1046 .open = cf_diag_open,
1047 .release = cf_diag_release,
1048 .unlocked_ioctl = cf_diag_ioctl,
1049 .compat_ioctl = cf_diag_ioctl,
1050 .llseek = no_llseek
1051 };
1052
1053 static struct miscdevice cf_diag_dev = {
1054 .name = S390_HWCTR_DEVICE,
1055 .minor = MISC_DYNAMIC_MINOR,
1056 .fops = &cf_diag_fops,
1057 };
1058
cf_diag_online_cpu(unsigned int cpu)1059 static int cf_diag_online_cpu(unsigned int cpu)
1060 {
1061 struct cf_diag_call_on_cpu_parm p;
1062
1063 mutex_lock(&cf_diag_ctrset_mutex);
1064 if (!cf_diag_ctrset.ctrset)
1065 goto out;
1066 p.sets = cf_diag_ctrset.ctrset;
1067 cf_diag_ioctl_on(&p);
1068 out:
1069 mutex_unlock(&cf_diag_ctrset_mutex);
1070 return 0;
1071 }
1072
cf_diag_offline_cpu(unsigned int cpu)1073 static int cf_diag_offline_cpu(unsigned int cpu)
1074 {
1075 struct cf_diag_call_on_cpu_parm p;
1076
1077 mutex_lock(&cf_diag_ctrset_mutex);
1078 if (!cf_diag_ctrset.ctrset)
1079 goto out;
1080 p.sets = cf_diag_ctrset.ctrset;
1081 cf_diag_ioctl_off(&p);
1082 out:
1083 mutex_unlock(&cf_diag_ctrset_mutex);
1084 return 0;
1085 }
1086
1087 /* Initialize the counter set PMU to generate complete counter set data as
1088 * event raw data. This relies on the CPU Measurement Counter Facility device
1089 * already being loaded and initialized.
1090 */
cf_diag_init(void)1091 static int __init cf_diag_init(void)
1092 {
1093 struct cpumf_ctr_info info;
1094 size_t need;
1095 int rc;
1096
1097 if (!kernel_cpumcf_avail() || !stccm_avail() || qctri(&info))
1098 return -ENODEV;
1099 cf_diag_get_cpu_speed();
1100
1101 /* Make sure the counter set data fits into predefined buffer. */
1102 need = cf_diag_ctrset_maxsize(&info);
1103 if (need > sizeof(((struct cf_diag_csd *)0)->start)) {
1104 pr_err("Insufficient memory for PMU(cpum_cf_diag) need=%zu\n",
1105 need);
1106 return -ENOMEM;
1107 }
1108
1109 rc = misc_register(&cf_diag_dev);
1110 if (rc) {
1111 pr_err("Registration of /dev/" S390_HWCTR_DEVICE
1112 "failed rc=%d\n", rc);
1113 goto out;
1114 }
1115
1116 /* Setup s390dbf facility */
1117 cf_diag_dbg = debug_register(KMSG_COMPONENT, 2, 1, 128);
1118 if (!cf_diag_dbg) {
1119 pr_err("Registration of s390dbf(cpum_cf_diag) failed\n");
1120 rc = -ENOMEM;
1121 goto out_dbf;
1122 }
1123 debug_register_view(cf_diag_dbg, &debug_sprintf_view);
1124
1125 rc = perf_pmu_register(&cf_diag, "cpum_cf_diag", -1);
1126 if (rc) {
1127 pr_err("Registration of PMU(cpum_cf_diag) failed with rc=%i\n",
1128 rc);
1129 goto out_perf;
1130 }
1131 rc = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_S390_CFD_ONLINE,
1132 "perf/s390/cfd:online",
1133 cf_diag_online_cpu, cf_diag_offline_cpu);
1134 if (!rc)
1135 goto out;
1136
1137 pr_err("Registration of CPUHP_AP_PERF_S390_CFD_ONLINE failed rc=%i\n",
1138 rc);
1139 perf_pmu_unregister(&cf_diag);
1140 out_perf:
1141 debug_unregister_view(cf_diag_dbg, &debug_sprintf_view);
1142 debug_unregister(cf_diag_dbg);
1143 out_dbf:
1144 misc_deregister(&cf_diag_dev);
1145 out:
1146 return rc;
1147 }
1148 device_initcall(cf_diag_init);
1149