1 /*
2 * Copyright 2014 Tilera Corporation. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
12 * more details.
13 *
14 *
15 * Perf_events support for Tile processor.
16 *
17 * This code is based upon the x86 perf event
18 * code, which is:
19 *
20 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
21 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
22 * Copyright (C) 2009 Jaswinder Singh Rajput
23 * Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
24 * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra
25 * Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com>
26 * Copyright (C) 2009 Google, Inc., Stephane Eranian
27 */
28
29 #include <linux/kprobes.h>
30 #include <linux/kernel.h>
31 #include <linux/kdebug.h>
32 #include <linux/mutex.h>
33 #include <linux/bitmap.h>
34 #include <linux/irq.h>
35 #include <linux/interrupt.h>
36 #include <linux/perf_event.h>
37 #include <linux/atomic.h>
38 #include <asm/traps.h>
39 #include <asm/stack.h>
40 #include <asm/pmc.h>
41 #include <hv/hypervisor.h>
42
43 #define TILE_MAX_COUNTERS 4
44
45 #define PERF_COUNT_0_IDX 0
46 #define PERF_COUNT_1_IDX 1
47 #define AUX_PERF_COUNT_0_IDX 2
48 #define AUX_PERF_COUNT_1_IDX 3
49
50 struct cpu_hw_events {
51 int n_events;
52 struct perf_event *events[TILE_MAX_COUNTERS]; /* counter order */
53 struct perf_event *event_list[TILE_MAX_COUNTERS]; /* enabled
54 order */
55 int assign[TILE_MAX_COUNTERS];
56 unsigned long active_mask[BITS_TO_LONGS(TILE_MAX_COUNTERS)];
57 unsigned long used_mask;
58 };
59
60 /* TILE arch specific performance monitor unit */
61 struct tile_pmu {
62 const char *name;
63 int version;
64 const int *hw_events; /* generic hw events table */
65 /* generic hw cache events table */
66 const int (*cache_events)[PERF_COUNT_HW_CACHE_MAX]
67 [PERF_COUNT_HW_CACHE_OP_MAX]
68 [PERF_COUNT_HW_CACHE_RESULT_MAX];
69 int (*map_hw_event)(u64); /*method used to map
70 hw events */
71 int (*map_cache_event)(u64); /*method used to map
72 cache events */
73
74 u64 max_period; /* max sampling period */
75 u64 cntval_mask; /* counter width mask */
76 int cntval_bits; /* counter width */
77 int max_events; /* max generic hw events
78 in map */
79 int num_counters; /* number base + aux counters */
80 int num_base_counters; /* number base counters */
81 };
82
83 DEFINE_PER_CPU(u64, perf_irqs);
84 static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
85
86 #define TILE_OP_UNSUPP (-1)
87
88 #ifndef __tilegx__
89 /* TILEPro hardware events map */
90 static const int tile_hw_event_map[] = {
91 [PERF_COUNT_HW_CPU_CYCLES] = 0x01, /* ONE */
92 [PERF_COUNT_HW_INSTRUCTIONS] = 0x06, /* MP_BUNDLE_RETIRED */
93 [PERF_COUNT_HW_CACHE_REFERENCES] = TILE_OP_UNSUPP,
94 [PERF_COUNT_HW_CACHE_MISSES] = TILE_OP_UNSUPP,
95 [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0x16, /*
96 MP_CONDITIONAL_BRANCH_ISSUED */
97 [PERF_COUNT_HW_BRANCH_MISSES] = 0x14, /*
98 MP_CONDITIONAL_BRANCH_MISSPREDICT */
99 [PERF_COUNT_HW_BUS_CYCLES] = TILE_OP_UNSUPP,
100 };
101 #else
102 /* TILEGx hardware events map */
103 static const int tile_hw_event_map[] = {
104 [PERF_COUNT_HW_CPU_CYCLES] = 0x181, /* ONE */
105 [PERF_COUNT_HW_INSTRUCTIONS] = 0xdb, /* INSTRUCTION_BUNDLE */
106 [PERF_COUNT_HW_CACHE_REFERENCES] = TILE_OP_UNSUPP,
107 [PERF_COUNT_HW_CACHE_MISSES] = TILE_OP_UNSUPP,
108 [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0xd9, /*
109 COND_BRANCH_PRED_CORRECT */
110 [PERF_COUNT_HW_BRANCH_MISSES] = 0xda, /*
111 COND_BRANCH_PRED_INCORRECT */
112 [PERF_COUNT_HW_BUS_CYCLES] = TILE_OP_UNSUPP,
113 };
114 #endif
115
116 #define C(x) PERF_COUNT_HW_CACHE_##x
117
118 /*
119 * Generalized hw caching related hw_event table, filled
120 * in on a per model basis. A value of -1 means
121 * 'not supported', any other value means the
122 * raw hw_event ID.
123 */
124 #ifndef __tilegx__
125 /* TILEPro hardware cache event map */
126 static const int tile_cache_event_map[PERF_COUNT_HW_CACHE_MAX]
127 [PERF_COUNT_HW_CACHE_OP_MAX]
128 [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
129 [C(L1D)] = {
130 [C(OP_READ)] = {
131 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
132 [C(RESULT_MISS)] = 0x21, /* RD_MISS */
133 },
134 [C(OP_WRITE)] = {
135 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
136 [C(RESULT_MISS)] = 0x22, /* WR_MISS */
137 },
138 [C(OP_PREFETCH)] = {
139 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
140 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
141 },
142 },
143 [C(L1I)] = {
144 [C(OP_READ)] = {
145 [C(RESULT_ACCESS)] = 0x12, /* MP_ICACHE_HIT_ISSUED */
146 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
147 },
148 [C(OP_WRITE)] = {
149 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
150 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
151 },
152 [C(OP_PREFETCH)] = {
153 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
154 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
155 },
156 },
157 [C(LL)] = {
158 [C(OP_READ)] = {
159 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
160 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
161 },
162 [C(OP_WRITE)] = {
163 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
164 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
165 },
166 [C(OP_PREFETCH)] = {
167 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
168 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
169 },
170 },
171 [C(DTLB)] = {
172 [C(OP_READ)] = {
173 [C(RESULT_ACCESS)] = 0x1d, /* TLB_CNT */
174 [C(RESULT_MISS)] = 0x20, /* TLB_EXCEPTION */
175 },
176 [C(OP_WRITE)] = {
177 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
178 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
179 },
180 [C(OP_PREFETCH)] = {
181 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
182 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
183 },
184 },
185 [C(ITLB)] = {
186 [C(OP_READ)] = {
187 [C(RESULT_ACCESS)] = 0x13, /* MP_ITLB_HIT_ISSUED */
188 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
189 },
190 [C(OP_WRITE)] = {
191 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
192 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
193 },
194 [C(OP_PREFETCH)] = {
195 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
196 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
197 },
198 },
199 [C(BPU)] = {
200 [C(OP_READ)] = {
201 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
202 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
203 },
204 [C(OP_WRITE)] = {
205 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
206 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
207 },
208 [C(OP_PREFETCH)] = {
209 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
210 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
211 },
212 },
213 };
214 #else
215 /* TILEGx hardware events map */
216 static const int tile_cache_event_map[PERF_COUNT_HW_CACHE_MAX]
217 [PERF_COUNT_HW_CACHE_OP_MAX]
218 [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
219 [C(L1D)] = {
220 /*
221 * Like some other architectures (e.g. ARM), the performance
222 * counters don't differentiate between read and write
223 * accesses/misses, so this isn't strictly correct, but it's the
224 * best we can do. Writes and reads get combined.
225 */
226 [C(OP_READ)] = {
227 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
228 [C(RESULT_MISS)] = 0x44, /* RD_MISS */
229 },
230 [C(OP_WRITE)] = {
231 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
232 [C(RESULT_MISS)] = 0x45, /* WR_MISS */
233 },
234 [C(OP_PREFETCH)] = {
235 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
236 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
237 },
238 },
239 [C(L1I)] = {
240 [C(OP_READ)] = {
241 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
242 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
243 },
244 [C(OP_WRITE)] = {
245 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
246 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
247 },
248 [C(OP_PREFETCH)] = {
249 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
250 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
251 },
252 },
253 [C(LL)] = {
254 [C(OP_READ)] = {
255 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
256 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
257 },
258 [C(OP_WRITE)] = {
259 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
260 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
261 },
262 [C(OP_PREFETCH)] = {
263 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
264 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
265 },
266 },
267 [C(DTLB)] = {
268 [C(OP_READ)] = {
269 [C(RESULT_ACCESS)] = 0x40, /* TLB_CNT */
270 [C(RESULT_MISS)] = 0x43, /* TLB_EXCEPTION */
271 },
272 [C(OP_WRITE)] = {
273 [C(RESULT_ACCESS)] = 0x40, /* TLB_CNT */
274 [C(RESULT_MISS)] = 0x43, /* TLB_EXCEPTION */
275 },
276 [C(OP_PREFETCH)] = {
277 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
278 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
279 },
280 },
281 [C(ITLB)] = {
282 [C(OP_READ)] = {
283 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
284 [C(RESULT_MISS)] = 0xd4, /* ITLB_MISS_INT */
285 },
286 [C(OP_WRITE)] = {
287 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
288 [C(RESULT_MISS)] = 0xd4, /* ITLB_MISS_INT */
289 },
290 [C(OP_PREFETCH)] = {
291 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
292 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
293 },
294 },
295 [C(BPU)] = {
296 [C(OP_READ)] = {
297 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
298 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
299 },
300 [C(OP_WRITE)] = {
301 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
302 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
303 },
304 [C(OP_PREFETCH)] = {
305 [C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
306 [C(RESULT_MISS)] = TILE_OP_UNSUPP,
307 },
308 },
309 };
310 #endif
311
312 static atomic_t tile_active_events;
313 static DEFINE_MUTEX(perf_intr_reserve_mutex);
314
315 static int tile_map_hw_event(u64 config);
316 static int tile_map_cache_event(u64 config);
317
318 static int tile_pmu_handle_irq(struct pt_regs *regs, int fault);
319
320 /*
321 * To avoid new_raw_count getting larger then pre_raw_count
322 * in tile_perf_event_update(), we limit the value of max_period to 2^31 - 1.
323 */
324 static const struct tile_pmu tilepmu = {
325 #ifndef __tilegx__
326 .name = "tilepro",
327 #else
328 .name = "tilegx",
329 #endif
330 .max_events = ARRAY_SIZE(tile_hw_event_map),
331 .map_hw_event = tile_map_hw_event,
332 .hw_events = tile_hw_event_map,
333 .map_cache_event = tile_map_cache_event,
334 .cache_events = &tile_cache_event_map,
335 .cntval_bits = 32,
336 .cntval_mask = (1ULL << 32) - 1,
337 .max_period = (1ULL << 31) - 1,
338 .num_counters = TILE_MAX_COUNTERS,
339 .num_base_counters = TILE_BASE_COUNTERS,
340 };
341
342 static const struct tile_pmu *tile_pmu __read_mostly;
343
344 /*
345 * Check whether perf event is enabled.
346 */
tile_perf_enabled(void)347 int tile_perf_enabled(void)
348 {
349 return atomic_read(&tile_active_events) != 0;
350 }
351
352 /*
353 * Read Performance Counters.
354 */
read_counter(int idx)355 static inline u64 read_counter(int idx)
356 {
357 u64 val = 0;
358
359 /* __insn_mfspr() only takes an immediate argument */
360 switch (idx) {
361 case PERF_COUNT_0_IDX:
362 val = __insn_mfspr(SPR_PERF_COUNT_0);
363 break;
364 case PERF_COUNT_1_IDX:
365 val = __insn_mfspr(SPR_PERF_COUNT_1);
366 break;
367 case AUX_PERF_COUNT_0_IDX:
368 val = __insn_mfspr(SPR_AUX_PERF_COUNT_0);
369 break;
370 case AUX_PERF_COUNT_1_IDX:
371 val = __insn_mfspr(SPR_AUX_PERF_COUNT_1);
372 break;
373 default:
374 WARN_ON_ONCE(idx > AUX_PERF_COUNT_1_IDX ||
375 idx < PERF_COUNT_0_IDX);
376 }
377
378 return val;
379 }
380
381 /*
382 * Write Performance Counters.
383 */
write_counter(int idx,u64 value)384 static inline void write_counter(int idx, u64 value)
385 {
386 /* __insn_mtspr() only takes an immediate argument */
387 switch (idx) {
388 case PERF_COUNT_0_IDX:
389 __insn_mtspr(SPR_PERF_COUNT_0, value);
390 break;
391 case PERF_COUNT_1_IDX:
392 __insn_mtspr(SPR_PERF_COUNT_1, value);
393 break;
394 case AUX_PERF_COUNT_0_IDX:
395 __insn_mtspr(SPR_AUX_PERF_COUNT_0, value);
396 break;
397 case AUX_PERF_COUNT_1_IDX:
398 __insn_mtspr(SPR_AUX_PERF_COUNT_1, value);
399 break;
400 default:
401 WARN_ON_ONCE(idx > AUX_PERF_COUNT_1_IDX ||
402 idx < PERF_COUNT_0_IDX);
403 }
404 }
405
406 /*
407 * Enable performance event by setting
408 * Performance Counter Control registers.
409 */
tile_pmu_enable_event(struct perf_event * event)410 static inline void tile_pmu_enable_event(struct perf_event *event)
411 {
412 struct hw_perf_event *hwc = &event->hw;
413 unsigned long cfg, mask;
414 int shift, idx = hwc->idx;
415
416 /*
417 * prevent early activation from tile_pmu_start() in hw_perf_enable
418 */
419
420 if (WARN_ON_ONCE(idx == -1))
421 return;
422
423 if (idx < tile_pmu->num_base_counters)
424 cfg = __insn_mfspr(SPR_PERF_COUNT_CTL);
425 else
426 cfg = __insn_mfspr(SPR_AUX_PERF_COUNT_CTL);
427
428 switch (idx) {
429 case PERF_COUNT_0_IDX:
430 case AUX_PERF_COUNT_0_IDX:
431 mask = TILE_EVENT_MASK;
432 shift = 0;
433 break;
434 case PERF_COUNT_1_IDX:
435 case AUX_PERF_COUNT_1_IDX:
436 mask = TILE_EVENT_MASK << 16;
437 shift = 16;
438 break;
439 default:
440 WARN_ON_ONCE(idx < PERF_COUNT_0_IDX ||
441 idx > AUX_PERF_COUNT_1_IDX);
442 return;
443 }
444
445 /* Clear mask bits to enable the event. */
446 cfg &= ~mask;
447 cfg |= hwc->config << shift;
448
449 if (idx < tile_pmu->num_base_counters)
450 __insn_mtspr(SPR_PERF_COUNT_CTL, cfg);
451 else
452 __insn_mtspr(SPR_AUX_PERF_COUNT_CTL, cfg);
453 }
454
455 /*
456 * Disable performance event by clearing
457 * Performance Counter Control registers.
458 */
tile_pmu_disable_event(struct perf_event * event)459 static inline void tile_pmu_disable_event(struct perf_event *event)
460 {
461 struct hw_perf_event *hwc = &event->hw;
462 unsigned long cfg, mask;
463 int idx = hwc->idx;
464
465 if (idx == -1)
466 return;
467
468 if (idx < tile_pmu->num_base_counters)
469 cfg = __insn_mfspr(SPR_PERF_COUNT_CTL);
470 else
471 cfg = __insn_mfspr(SPR_AUX_PERF_COUNT_CTL);
472
473 switch (idx) {
474 case PERF_COUNT_0_IDX:
475 case AUX_PERF_COUNT_0_IDX:
476 mask = TILE_PLM_MASK;
477 break;
478 case PERF_COUNT_1_IDX:
479 case AUX_PERF_COUNT_1_IDX:
480 mask = TILE_PLM_MASK << 16;
481 break;
482 default:
483 WARN_ON_ONCE(idx < PERF_COUNT_0_IDX ||
484 idx > AUX_PERF_COUNT_1_IDX);
485 return;
486 }
487
488 /* Set mask bits to disable the event. */
489 cfg |= mask;
490
491 if (idx < tile_pmu->num_base_counters)
492 __insn_mtspr(SPR_PERF_COUNT_CTL, cfg);
493 else
494 __insn_mtspr(SPR_AUX_PERF_COUNT_CTL, cfg);
495 }
496
497 /*
498 * Propagate event elapsed time into the generic event.
499 * Can only be executed on the CPU where the event is active.
500 * Returns the delta events processed.
501 */
tile_perf_event_update(struct perf_event * event)502 static u64 tile_perf_event_update(struct perf_event *event)
503 {
504 struct hw_perf_event *hwc = &event->hw;
505 int shift = 64 - tile_pmu->cntval_bits;
506 u64 prev_raw_count, new_raw_count;
507 u64 oldval;
508 int idx = hwc->idx;
509 u64 delta;
510
511 /*
512 * Careful: an NMI might modify the previous event value.
513 *
514 * Our tactic to handle this is to first atomically read and
515 * exchange a new raw count - then add that new-prev delta
516 * count to the generic event atomically:
517 */
518 again:
519 prev_raw_count = local64_read(&hwc->prev_count);
520 new_raw_count = read_counter(idx);
521
522 oldval = local64_cmpxchg(&hwc->prev_count, prev_raw_count,
523 new_raw_count);
524 if (oldval != prev_raw_count)
525 goto again;
526
527 /*
528 * Now we have the new raw value and have updated the prev
529 * timestamp already. We can now calculate the elapsed delta
530 * (event-)time and add that to the generic event.
531 *
532 * Careful, not all hw sign-extends above the physical width
533 * of the count.
534 */
535 delta = (new_raw_count << shift) - (prev_raw_count << shift);
536 delta >>= shift;
537
538 local64_add(delta, &event->count);
539 local64_sub(delta, &hwc->period_left);
540
541 return new_raw_count;
542 }
543
544 /*
545 * Set the next IRQ period, based on the hwc->period_left value.
546 * To be called with the event disabled in hw:
547 */
tile_event_set_period(struct perf_event * event)548 static int tile_event_set_period(struct perf_event *event)
549 {
550 struct hw_perf_event *hwc = &event->hw;
551 int idx = hwc->idx;
552 s64 left = local64_read(&hwc->period_left);
553 s64 period = hwc->sample_period;
554 int ret = 0;
555
556 /*
557 * If we are way outside a reasonable range then just skip forward:
558 */
559 if (unlikely(left <= -period)) {
560 left = period;
561 local64_set(&hwc->period_left, left);
562 hwc->last_period = period;
563 ret = 1;
564 }
565
566 if (unlikely(left <= 0)) {
567 left += period;
568 local64_set(&hwc->period_left, left);
569 hwc->last_period = period;
570 ret = 1;
571 }
572 if (left > tile_pmu->max_period)
573 left = tile_pmu->max_period;
574
575 /*
576 * The hw event starts counting from this event offset,
577 * mark it to be able to extra future deltas:
578 */
579 local64_set(&hwc->prev_count, (u64)-left);
580
581 write_counter(idx, (u64)(-left) & tile_pmu->cntval_mask);
582
583 perf_event_update_userpage(event);
584
585 return ret;
586 }
587
588 /*
589 * Stop the event but do not release the PMU counter
590 */
tile_pmu_stop(struct perf_event * event,int flags)591 static void tile_pmu_stop(struct perf_event *event, int flags)
592 {
593 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
594 struct hw_perf_event *hwc = &event->hw;
595 int idx = hwc->idx;
596
597 if (__test_and_clear_bit(idx, cpuc->active_mask)) {
598 tile_pmu_disable_event(event);
599 cpuc->events[hwc->idx] = NULL;
600 WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
601 hwc->state |= PERF_HES_STOPPED;
602 }
603
604 if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
605 /*
606 * Drain the remaining delta count out of a event
607 * that we are disabling:
608 */
609 tile_perf_event_update(event);
610 hwc->state |= PERF_HES_UPTODATE;
611 }
612 }
613
614 /*
615 * Start an event (without re-assigning counter)
616 */
tile_pmu_start(struct perf_event * event,int flags)617 static void tile_pmu_start(struct perf_event *event, int flags)
618 {
619 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
620 int idx = event->hw.idx;
621
622 if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
623 return;
624
625 if (WARN_ON_ONCE(idx == -1))
626 return;
627
628 if (flags & PERF_EF_RELOAD) {
629 WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
630 tile_event_set_period(event);
631 }
632
633 event->hw.state = 0;
634
635 cpuc->events[idx] = event;
636 __set_bit(idx, cpuc->active_mask);
637
638 unmask_pmc_interrupts();
639
640 tile_pmu_enable_event(event);
641
642 perf_event_update_userpage(event);
643 }
644
645 /*
646 * Add a single event to the PMU.
647 *
648 * The event is added to the group of enabled events
649 * but only if it can be scehduled with existing events.
650 */
tile_pmu_add(struct perf_event * event,int flags)651 static int tile_pmu_add(struct perf_event *event, int flags)
652 {
653 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
654 struct hw_perf_event *hwc;
655 unsigned long mask;
656 int b, max_cnt;
657
658 hwc = &event->hw;
659
660 /*
661 * We are full.
662 */
663 if (cpuc->n_events == tile_pmu->num_counters)
664 return -ENOSPC;
665
666 cpuc->event_list[cpuc->n_events] = event;
667 cpuc->n_events++;
668
669 hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
670 if (!(flags & PERF_EF_START))
671 hwc->state |= PERF_HES_ARCH;
672
673 /*
674 * Find first empty counter.
675 */
676 max_cnt = tile_pmu->num_counters;
677 mask = ~cpuc->used_mask;
678
679 /* Find next free counter. */
680 b = find_next_bit(&mask, max_cnt, 0);
681
682 /* Should not happen. */
683 if (WARN_ON_ONCE(b == max_cnt))
684 return -ENOSPC;
685
686 /*
687 * Assign counter to event.
688 */
689 event->hw.idx = b;
690 __set_bit(b, &cpuc->used_mask);
691
692 /*
693 * Start if requested.
694 */
695 if (flags & PERF_EF_START)
696 tile_pmu_start(event, PERF_EF_RELOAD);
697
698 return 0;
699 }
700
701 /*
702 * Delete a single event from the PMU.
703 *
704 * The event is deleted from the group of enabled events.
705 * If it is the last event, disable PMU interrupt.
706 */
tile_pmu_del(struct perf_event * event,int flags)707 static void tile_pmu_del(struct perf_event *event, int flags)
708 {
709 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
710 int i;
711
712 /*
713 * Remove event from list, compact list if necessary.
714 */
715 for (i = 0; i < cpuc->n_events; i++) {
716 if (cpuc->event_list[i] == event) {
717 while (++i < cpuc->n_events)
718 cpuc->event_list[i-1] = cpuc->event_list[i];
719 --cpuc->n_events;
720 cpuc->events[event->hw.idx] = NULL;
721 __clear_bit(event->hw.idx, &cpuc->used_mask);
722 tile_pmu_stop(event, PERF_EF_UPDATE);
723 break;
724 }
725 }
726 /*
727 * If there are no events left, then mask PMU interrupt.
728 */
729 if (cpuc->n_events == 0)
730 mask_pmc_interrupts();
731 perf_event_update_userpage(event);
732 }
733
734 /*
735 * Propagate event elapsed time into the event.
736 */
tile_pmu_read(struct perf_event * event)737 static inline void tile_pmu_read(struct perf_event *event)
738 {
739 tile_perf_event_update(event);
740 }
741
742 /*
743 * Map generic events to Tile PMU.
744 */
tile_map_hw_event(u64 config)745 static int tile_map_hw_event(u64 config)
746 {
747 if (config >= tile_pmu->max_events)
748 return -EINVAL;
749 return tile_pmu->hw_events[config];
750 }
751
752 /*
753 * Map generic hardware cache events to Tile PMU.
754 */
tile_map_cache_event(u64 config)755 static int tile_map_cache_event(u64 config)
756 {
757 unsigned int cache_type, cache_op, cache_result;
758 int code;
759
760 if (!tile_pmu->cache_events)
761 return -ENOENT;
762
763 cache_type = (config >> 0) & 0xff;
764 if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
765 return -EINVAL;
766
767 cache_op = (config >> 8) & 0xff;
768 if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
769 return -EINVAL;
770
771 cache_result = (config >> 16) & 0xff;
772 if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
773 return -EINVAL;
774
775 code = (*tile_pmu->cache_events)[cache_type][cache_op][cache_result];
776 if (code == TILE_OP_UNSUPP)
777 return -EINVAL;
778
779 return code;
780 }
781
tile_event_destroy(struct perf_event * event)782 static void tile_event_destroy(struct perf_event *event)
783 {
784 if (atomic_dec_return(&tile_active_events) == 0)
785 release_pmc_hardware();
786 }
787
__tile_event_init(struct perf_event * event)788 static int __tile_event_init(struct perf_event *event)
789 {
790 struct perf_event_attr *attr = &event->attr;
791 struct hw_perf_event *hwc = &event->hw;
792 int code;
793
794 switch (attr->type) {
795 case PERF_TYPE_HARDWARE:
796 code = tile_pmu->map_hw_event(attr->config);
797 break;
798 case PERF_TYPE_HW_CACHE:
799 code = tile_pmu->map_cache_event(attr->config);
800 break;
801 case PERF_TYPE_RAW:
802 code = attr->config & TILE_EVENT_MASK;
803 break;
804 default:
805 /* Should not happen. */
806 return -EOPNOTSUPP;
807 }
808
809 if (code < 0)
810 return code;
811
812 hwc->config = code;
813 hwc->idx = -1;
814
815 if (attr->exclude_user)
816 hwc->config |= TILE_CTL_EXCL_USER;
817
818 if (attr->exclude_kernel)
819 hwc->config |= TILE_CTL_EXCL_KERNEL;
820
821 if (attr->exclude_hv)
822 hwc->config |= TILE_CTL_EXCL_HV;
823
824 if (!hwc->sample_period) {
825 hwc->sample_period = tile_pmu->max_period;
826 hwc->last_period = hwc->sample_period;
827 local64_set(&hwc->period_left, hwc->sample_period);
828 }
829 event->destroy = tile_event_destroy;
830 return 0;
831 }
832
tile_event_init(struct perf_event * event)833 static int tile_event_init(struct perf_event *event)
834 {
835 int err = 0;
836 perf_irq_t old_irq_handler = NULL;
837
838 if (atomic_inc_return(&tile_active_events) == 1)
839 old_irq_handler = reserve_pmc_hardware(tile_pmu_handle_irq);
840
841 if (old_irq_handler) {
842 pr_warn("PMC hardware busy (reserved by oprofile)\n");
843
844 atomic_dec(&tile_active_events);
845 return -EBUSY;
846 }
847
848 switch (event->attr.type) {
849 case PERF_TYPE_RAW:
850 case PERF_TYPE_HARDWARE:
851 case PERF_TYPE_HW_CACHE:
852 break;
853
854 default:
855 return -ENOENT;
856 }
857
858 err = __tile_event_init(event);
859 if (err) {
860 if (event->destroy)
861 event->destroy(event);
862 }
863 return err;
864 }
865
866 static struct pmu tilera_pmu = {
867 .event_init = tile_event_init,
868 .add = tile_pmu_add,
869 .del = tile_pmu_del,
870
871 .start = tile_pmu_start,
872 .stop = tile_pmu_stop,
873
874 .read = tile_pmu_read,
875 };
876
877 /*
878 * PMU's IRQ handler, PMU has 2 interrupts, they share the same handler.
879 */
tile_pmu_handle_irq(struct pt_regs * regs,int fault)880 int tile_pmu_handle_irq(struct pt_regs *regs, int fault)
881 {
882 struct perf_sample_data data;
883 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
884 struct perf_event *event;
885 struct hw_perf_event *hwc;
886 u64 val;
887 unsigned long status;
888 int bit;
889
890 __this_cpu_inc(perf_irqs);
891
892 if (!atomic_read(&tile_active_events))
893 return 0;
894
895 status = pmc_get_overflow();
896 pmc_ack_overflow(status);
897
898 for_each_set_bit(bit, &status, tile_pmu->num_counters) {
899
900 event = cpuc->events[bit];
901
902 if (!event)
903 continue;
904
905 if (!test_bit(bit, cpuc->active_mask))
906 continue;
907
908 hwc = &event->hw;
909
910 val = tile_perf_event_update(event);
911 if (val & (1ULL << (tile_pmu->cntval_bits - 1)))
912 continue;
913
914 perf_sample_data_init(&data, 0, event->hw.last_period);
915 if (!tile_event_set_period(event))
916 continue;
917
918 if (perf_event_overflow(event, &data, regs))
919 tile_pmu_stop(event, 0);
920 }
921
922 return 0;
923 }
924
supported_pmu(void)925 static bool __init supported_pmu(void)
926 {
927 tile_pmu = &tilepmu;
928 return true;
929 }
930
init_hw_perf_events(void)931 int __init init_hw_perf_events(void)
932 {
933 supported_pmu();
934 perf_pmu_register(&tilera_pmu, "cpu", PERF_TYPE_RAW);
935 return 0;
936 }
937 arch_initcall(init_hw_perf_events);
938
939 /* Callchain handling code. */
940
941 /*
942 * Tile specific backtracing code for perf_events.
943 */
perf_callchain(struct perf_callchain_entry_ctx * entry,struct pt_regs * regs)944 static inline void perf_callchain(struct perf_callchain_entry_ctx *entry,
945 struct pt_regs *regs)
946 {
947 struct KBacktraceIterator kbt;
948 unsigned int i;
949
950 /*
951 * Get the address just after the "jalr" instruction that
952 * jumps to the handler for a syscall. When we find this
953 * address in a backtrace, we silently ignore it, which gives
954 * us a one-step backtrace connection from the sys_xxx()
955 * function in the kernel to the xxx() function in libc.
956 * Otherwise, we lose the ability to properly attribute time
957 * from the libc calls to the kernel implementations, since
958 * oprofile only considers PCs from backtraces a pair at a time.
959 */
960 unsigned long handle_syscall_pc = handle_syscall_link_address();
961
962 KBacktraceIterator_init(&kbt, NULL, regs);
963 kbt.profile = 1;
964
965 /*
966 * The sample for the pc is already recorded. Now we are adding the
967 * address of the callsites on the stack. Our iterator starts
968 * with the frame of the (already sampled) call site. If our
969 * iterator contained a "return address" field, we could have just
970 * used it and wouldn't have needed to skip the first
971 * frame. That's in effect what the arm and x86 versions do.
972 * Instead we peel off the first iteration to get the equivalent
973 * behavior.
974 */
975
976 if (KBacktraceIterator_end(&kbt))
977 return;
978 KBacktraceIterator_next(&kbt);
979
980 /*
981 * Set stack depth to 16 for user and kernel space respectively, that
982 * is, total 32 stack frames.
983 */
984 for (i = 0; i < 16; ++i) {
985 unsigned long pc;
986 if (KBacktraceIterator_end(&kbt))
987 break;
988 pc = kbt.it.pc;
989 if (pc != handle_syscall_pc)
990 perf_callchain_store(entry, pc);
991 KBacktraceIterator_next(&kbt);
992 }
993 }
994
perf_callchain_user(struct perf_callchain_entry_ctx * entry,struct pt_regs * regs)995 void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
996 struct pt_regs *regs)
997 {
998 perf_callchain(entry, regs);
999 }
1000
perf_callchain_kernel(struct perf_callchain_entry_ctx * entry,struct pt_regs * regs)1001 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
1002 struct pt_regs *regs)
1003 {
1004 perf_callchain(entry, regs);
1005 }
1006