summaryrefslogtreecommitdiffstats
path: root/tools/perf/arch/arm64/util/arm-spe.c
blob: 51ccbfd3d246d484400c9a83220efaa8833f9f95 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
// SPDX-License-Identifier: GPL-2.0
/*
 * Arm Statistical Profiling Extensions (SPE) support
 * Copyright (c) 2017-2018, Arm Ltd.
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/log2.h>
#include <linux/zalloc.h>
#include <time.h>

#include "../../../util/cpumap.h"
#include "../../../util/event.h"
#include "../../../util/evsel.h"
#include "../../../util/evsel_config.h"
#include "../../../util/evlist.h"
#include "../../../util/session.h"
#include <internal/lib.h> // page_size
#include "../../../util/pmu.h"
#include "../../../util/debug.h"
#include "../../../util/auxtrace.h"
#include "../../../util/record.h"
#include "../../../util/arm-spe.h"
#include <tools/libc_compat.h> // reallocarray

#define KiB(x) ((x) * 1024)
#define MiB(x) ((x) * 1024 * 1024)

struct arm_spe_recording {
	struct auxtrace_record		itr;
	struct perf_pmu			*arm_spe_pmu;
	struct evlist		*evlist;
	int			wrapped_cnt;
	bool			*wrapped;
};

static size_t
arm_spe_info_priv_size(struct auxtrace_record *itr __maybe_unused,
		       struct evlist *evlist __maybe_unused)
{
	return ARM_SPE_AUXTRACE_PRIV_SIZE;
}

static int arm_spe_info_fill(struct auxtrace_record *itr,
			     struct perf_session *session,
			     struct perf_record_auxtrace_info *auxtrace_info,
			     size_t priv_size)
{
	struct arm_spe_recording *sper =
			container_of(itr, struct arm_spe_recording, itr);
	struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;

	if (priv_size != ARM_SPE_AUXTRACE_PRIV_SIZE)
		return -EINVAL;

	if (!session->evlist->core.nr_mmaps)
		return -EINVAL;

	auxtrace_info->type = PERF_AUXTRACE_ARM_SPE;
	auxtrace_info->priv[ARM_SPE_PMU_TYPE] = arm_spe_pmu->type;

	return 0;
}

static void
arm_spe_snapshot_resolve_auxtrace_defaults(struct record_opts *opts,
					   bool privileged)
{
	/*
	 * The default snapshot size is the auxtrace mmap size. If neither auxtrace mmap size nor
	 * snapshot size is specified, then the default is 4MiB for privileged users, 128KiB for
	 * unprivileged users.
	 *
	 * The default auxtrace mmap size is 4MiB/page_size for privileged users, 128KiB for
	 * unprivileged users. If an unprivileged user does not specify mmap pages, the mmap pages
	 * will be reduced from the default 512KiB/page_size to 256KiB/page_size, otherwise the
	 * user is likely to get an error as they exceed their mlock limmit.
	 */

	/*
	 * No size were given to '-S' or '-m,', so go with the default
	 */
	if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) {
		if (privileged) {
			opts->auxtrace_mmap_pages = MiB(4) / page_size;
		} else {
			opts->auxtrace_mmap_pages = KiB(128) / page_size;
			if (opts->mmap_pages == UINT_MAX)
				opts->mmap_pages = KiB(256) / page_size;
		}
	} else if (!opts->auxtrace_mmap_pages && !privileged && opts->mmap_pages == UINT_MAX) {
		opts->mmap_pages = KiB(256) / page_size;
	}

	/*
	 * '-m,xyz' was specified but no snapshot size, so make the snapshot size as big as the
	 * auxtrace mmap area.
	 */
	if (!opts->auxtrace_snapshot_size)
		opts->auxtrace_snapshot_size = opts->auxtrace_mmap_pages * (size_t)page_size;

	/*
	 * '-Sxyz' was specified but no auxtrace mmap area, so make the auxtrace mmap area big
	 * enough to fit the requested snapshot size.
	 */
	if (!opts->auxtrace_mmap_pages) {
		size_t sz = opts->auxtrace_snapshot_size;

		sz = round_up(sz, page_size) / page_size;
		opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
	}
}

static __u64 arm_spe_pmu__sample_period(const struct perf_pmu *arm_spe_pmu)
{
	static __u64 sample_period;

	if (sample_period)
		return sample_period;

	/*
	 * If kernel driver doesn't advertise a minimum,
	 * use max allowable by PMSIDR_EL1.INTERVAL
	 */
	if (perf_pmu__scan_file(arm_spe_pmu, "caps/min_interval", "%llu",
				&sample_period) != 1) {
		pr_debug("arm_spe driver doesn't advertise a min. interval. Using 4096\n");
		sample_period = 4096;
	}
	return sample_period;
}

static int arm_spe_recording_options(struct auxtrace_record *itr,
				     struct evlist *evlist,
				     struct record_opts *opts)
{
	struct arm_spe_recording *sper =
			container_of(itr, struct arm_spe_recording, itr);
	struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
	struct evsel *evsel, *arm_spe_evsel = NULL;
	struct perf_cpu_map *cpus = evlist->core.user_requested_cpus;
	bool privileged = perf_event_paranoid_check(-1);
	struct evsel *tracking_evsel;
	int err;
	u64 bit;

	sper->evlist = evlist;

	evlist__for_each_entry(evlist, evsel) {
		if (evsel->core.attr.type == arm_spe_pmu->type) {
			if (arm_spe_evsel) {
				pr_err("There may be only one " ARM_SPE_PMU_NAME "x event\n");
				return -EINVAL;
			}
			evsel->core.attr.freq = 0;
			evsel->core.attr.sample_period = arm_spe_pmu__sample_period(arm_spe_pmu);
			evsel->needs_auxtrace_mmap = true;
			arm_spe_evsel = evsel;
			opts->full_auxtrace = true;
		}
	}

	if (!opts->full_auxtrace)
		return 0;

	/*
	 * we are in snapshot mode.
	 */
	if (opts->auxtrace_snapshot_mode) {
		/*
		 * Command arguments '-Sxyz' and/or '-m,xyz' are missing, so fill those in with
		 * default values.
		 */
		if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages)
			arm_spe_snapshot_resolve_auxtrace_defaults(opts, privileged);

		/*
		 * Snapshot size can't be bigger than the auxtrace area.
		 */
		if (opts->auxtrace_snapshot_size > opts->auxtrace_mmap_pages * (size_t)page_size) {
			pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
			       opts->auxtrace_snapshot_size,
			       opts->auxtrace_mmap_pages * (size_t)page_size);
			return -EINVAL;
		}

		/*
		 * Something went wrong somewhere - this shouldn't happen.
		 */
		if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) {
			pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
			return -EINVAL;
		}
	}

	/* We are in full trace mode but '-m,xyz' wasn't specified */
	if (!opts->auxtrace_mmap_pages) {
		if (privileged) {
			opts->auxtrace_mmap_pages = MiB(4) / page_size;
		} else {
			opts->auxtrace_mmap_pages = KiB(128) / page_size;
			if (opts->mmap_pages == UINT_MAX)
				opts->mmap_pages = KiB(256) / page_size;
		}
	}

	/* Validate auxtrace_mmap_pages */
	if (opts->auxtrace_mmap_pages) {
		size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
		size_t min_sz = KiB(8);

		if (sz < min_sz || !is_power_of_2(sz)) {
			pr_err("Invalid mmap size for ARM SPE: must be at least %zuKiB and a power of 2\n",
			       min_sz / 1024);
			return -EINVAL;
		}
	}

	if (opts->auxtrace_snapshot_mode)
		pr_debug2("%sx snapshot size: %zu\n", ARM_SPE_PMU_NAME,
			  opts->auxtrace_snapshot_size);

	/*
	 * To obtain the auxtrace buffer file descriptor, the auxtrace event
	 * must come first.
	 */
	evlist__to_front(evlist, arm_spe_evsel);

	/*
	 * In the case of per-cpu mmaps, sample CPU for AUX event;
	 * also enable the timestamp tracing for samples correlation.
	 */
	if (!perf_cpu_map__has_any_cpu_or_is_empty(cpus)) {
		evsel__set_sample_bit(arm_spe_evsel, CPU);
		evsel__set_config_if_unset(arm_spe_pmu, arm_spe_evsel,
					   "ts_enable", 1);
	}

	/*
	 * Set this only so that perf report knows that SPE generates memory info. It has no effect
	 * on the opening of the event or the SPE data produced.
	 */
	evsel__set_sample_bit(arm_spe_evsel, DATA_SRC);

	/*
	 * The PHYS_ADDR flag does not affect the driver behaviour, it is used to
	 * inform that the resulting output's SPE samples contain physical addresses
	 * where applicable.
	 */
	bit = perf_pmu__format_bits(arm_spe_pmu, "pa_enable");
	if (arm_spe_evsel->core.attr.config & bit)
		evsel__set_sample_bit(arm_spe_evsel, PHYS_ADDR);

	/* Add dummy event to keep tracking */
	err = parse_event(evlist, "dummy:u");
	if (err)
		return err;

	tracking_evsel = evlist__last(evlist);
	evlist__set_tracking_event(evlist, tracking_evsel);

	tracking_evsel->core.attr.freq = 0;
	tracking_evsel->core.attr.sample_period = 1;

	/* In per-cpu case, always need the time of mmap events etc */
	if (!perf_cpu_map__has_any_cpu_or_is_empty(cpus)) {
		evsel__set_sample_bit(tracking_evsel, TIME);
		evsel__set_sample_bit(tracking_evsel, CPU);

		/* also track task context switch */
		if (!record_opts__no_switch_events(opts))
			tracking_evsel->core.attr.context_switch = 1;
	}

	return 0;
}

static int arm_spe_parse_snapshot_options(struct auxtrace_record *itr __maybe_unused,
					 struct record_opts *opts,
					 const char *str)
{
	unsigned long long snapshot_size = 0;
	char *endptr;

	if (str) {
		snapshot_size = strtoull(str, &endptr, 0);
		if (*endptr || snapshot_size > SIZE_MAX)
			return -1;
	}

	opts->auxtrace_snapshot_mode = true;
	opts->auxtrace_snapshot_size = snapshot_size;

	return 0;
}

static int arm_spe_snapshot_start(struct auxtrace_record *itr)
{
	struct arm_spe_recording *ptr =
			container_of(itr, struct arm_spe_recording, itr);
	struct evsel *evsel;

	evlist__for_each_entry(ptr->evlist, evsel) {
		if (evsel->core.attr.type == ptr->arm_spe_pmu->type)
			return evsel__disable(evsel);
	}
	return -EINVAL;
}

static int arm_spe_snapshot_finish(struct auxtrace_record *itr)
{
	struct arm_spe_recording *ptr =
			container_of(itr, struct arm_spe_recording, itr);
	struct evsel *evsel;

	evlist__for_each_entry(ptr->evlist, evsel) {
		if (evsel->core.attr.type == ptr->arm_spe_pmu->type)
			return evsel__enable(evsel);
	}
	return -EINVAL;
}

static int arm_spe_alloc_wrapped_array(struct arm_spe_recording *ptr, int idx)
{
	bool *wrapped;
	int cnt = ptr->wrapped_cnt, new_cnt, i;

	/*
	 * No need to allocate, so return early.
	 */
	if (idx < cnt)
		return 0;

	/*
	 * Make ptr->wrapped as big as idx.
	 */
	new_cnt = idx + 1;

	/*
	 * Free'ed in arm_spe_recording_free().
	 */
	wrapped = reallocarray(ptr->wrapped, new_cnt, sizeof(bool));
	if (!wrapped)
		return -ENOMEM;

	/*
	 * init new allocated values.
	 */
	for (i = cnt; i < new_cnt; i++)
		wrapped[i] = false;

	ptr->wrapped_cnt = new_cnt;
	ptr->wrapped = wrapped;

	return 0;
}

static bool arm_spe_buffer_has_wrapped(unsigned char *buffer,
				      size_t buffer_size, u64 head)
{
	u64 i, watermark;
	u64 *buf = (u64 *)buffer;
	size_t buf_size = buffer_size;

	/*
	 * Defensively handle the case where head might be continually increasing - if its value is
	 * equal or greater than the size of the ring buffer, then we can safely determine it has
	 * wrapped around. Otherwise, continue to detect if head might have wrapped.
	 */
	if (head >= buffer_size)
		return true;

	/*
	 * We want to look the very last 512 byte (chosen arbitrarily) in the ring buffer.
	 */
	watermark = buf_size - 512;

	/*
	 * The value of head is somewhere within the size of the ring buffer. This can be that there
	 * hasn't been enough data to fill the ring buffer yet or the trace time was so long that
	 * head has numerically wrapped around.  To find we need to check if we have data at the
	 * very end of the ring buffer.  We can reliably do this because mmap'ed pages are zeroed
	 * out and there is a fresh mapping with every new session.
	 */

	/*
	 * head is less than 512 byte from the end of the ring buffer.
	 */
	if (head > watermark)
		watermark = head;

	/*
	 * Speed things up by using 64 bit transactions (see "u64 *buf" above)
	 */
	watermark /= sizeof(u64);
	buf_size /= sizeof(u64);

	/*
	 * If we find trace data at the end of the ring buffer, head has been there and has
	 * numerically wrapped around at least once.
	 */
	for (i = watermark; i < buf_size; i++)
		if (buf[i])
			return true;

	return false;
}

static int arm_spe_find_snapshot(struct auxtrace_record *itr, int idx,
				  struct auxtrace_mmap *mm, unsigned char *data,
				  u64 *head, u64 *old)
{
	int err;
	bool wrapped;
	struct arm_spe_recording *ptr =
			container_of(itr, struct arm_spe_recording, itr);

	/*
	 * Allocate memory to keep track of wrapping if this is the first
	 * time we deal with this *mm.
	 */
	if (idx >= ptr->wrapped_cnt) {
		err = arm_spe_alloc_wrapped_array(ptr, idx);
		if (err)
			return err;
	}

	/*
	 * Check to see if *head has wrapped around.  If it hasn't only the
	 * amount of data between *head and *old is snapshot'ed to avoid
	 * bloating the perf.data file with zeros.  But as soon as *head has
	 * wrapped around the entire size of the AUX ring buffer it taken.
	 */
	wrapped = ptr->wrapped[idx];
	if (!wrapped && arm_spe_buffer_has_wrapped(data, mm->len, *head)) {
		wrapped = true;
		ptr->wrapped[idx] = true;
	}

	pr_debug3("%s: mmap index %d old head %zu new head %zu size %zu\n",
		  __func__, idx, (size_t)*old, (size_t)*head, mm->len);

	/*
	 * No wrap has occurred, we can just use *head and *old.
	 */
	if (!wrapped)
		return 0;

	/*
	 * *head has wrapped around - adjust *head and *old to pickup the
	 * entire content of the AUX buffer.
	 */
	if (*head >= mm->len) {
		*old = *head - mm->len;
	} else {
		*head += mm->len;
		*old = *head - mm->len;
	}

	return 0;
}

static u64 arm_spe_reference(struct auxtrace_record *itr __maybe_unused)
{
	struct timespec ts;

	clock_gettime(CLOCK_MONOTONIC_RAW, &ts);

	return ts.tv_sec ^ ts.tv_nsec;
}

static void arm_spe_recording_free(struct auxtrace_record *itr)
{
	struct arm_spe_recording *sper =
			container_of(itr, struct arm_spe_recording, itr);

	zfree(&sper->wrapped);
	free(sper);
}

struct auxtrace_record *arm_spe_recording_init(int *err,
					       struct perf_pmu *arm_spe_pmu)
{
	struct arm_spe_recording *sper;

	if (!arm_spe_pmu) {
		*err = -ENODEV;
		return NULL;
	}

	sper = zalloc(sizeof(struct arm_spe_recording));
	if (!sper) {
		*err = -ENOMEM;
		return NULL;
	}

	sper->arm_spe_pmu = arm_spe_pmu;
	sper->itr.pmu = arm_spe_pmu;
	sper->itr.snapshot_start = arm_spe_snapshot_start;
	sper->itr.snapshot_finish = arm_spe_snapshot_finish;
	sper->itr.find_snapshot = arm_spe_find_snapshot;
	sper->itr.parse_snapshot_options = arm_spe_parse_snapshot_options;
	sper->itr.recording_options = arm_spe_recording_options;
	sper->itr.info_priv_size = arm_spe_info_priv_size;
	sper->itr.info_fill = arm_spe_info_fill;
	sper->itr.free = arm_spe_recording_free;
	sper->itr.reference = arm_spe_reference;
	sper->itr.read_finish = auxtrace_record__read_finish;
	sper->itr.alignment = 0;

	*err = 0;
	return &sper->itr;
}

void
arm_spe_pmu_default_config(const struct perf_pmu *arm_spe_pmu, struct perf_event_attr *attr)
{
	attr->sample_period = arm_spe_pmu__sample_period(arm_spe_pmu);
}