tools/perf/arch/x86/util/intel-pt.c

   1 /*
   2  * intel_pt.c: Intel Processor Trace support
   3  * Copyright (c) 2013-2015, Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  */
  15
  16 #include <errno.h>
  17 #include <stdbool.h>
  18 #include <linux/kernel.h>
  19 #include <linux/types.h>
  20 #include <linux/bitops.h>
  21 #include <linux/log2.h>
  22 #include <cpuid.h>
  23
  24 #include "../../perf.h"
  25 #include "../../util/session.h"
  26 #include "../../util/event.h"
  27 #include "../../util/evlist.h"
  28 #include "../../util/evsel.h"
  29 #include "../../util/cpumap.h"
  30 #include <subcmd/parse-options.h>
  31 #include "../../util/parse-events.h"
  32 #include "../../util/pmu.h"
  33 #include "../../util/debug.h"
  34 #include "../../util/auxtrace.h"
  35 #include "../../util/tsc.h"
  36 #include "../../util/intel-pt.h"
  37
  38 #define KiB(x) ((x) * 1024)
  39 #define MiB(x) ((x) * 1024 * 1024)
  40 #define KiB_MASK(x) (KiB(x) - 1)
  41 #define MiB_MASK(x) (MiB(x) - 1)
  42
  43 #define INTEL_PT_PSB_PERIOD_NEAR        256
  44
  45 struct intel_pt_snapshot_ref {
  46         void *ref_buf;
  47         size_t ref_offset;
  48         bool wrapped;
  49 };
  50
  51 struct intel_pt_recording {
  52         struct auxtrace_record          itr;
  53         struct perf_pmu                 *intel_pt_pmu;
  54         int                             have_sched_switch;
  55         struct perf_evlist              *evlist;
  56         bool                            snapshot_mode;
  57         bool                            snapshot_init_done;
  58         size_t                          snapshot_size;
  59         size_t                          snapshot_ref_buf_size;
  60         int                             snapshot_ref_cnt;
  61         struct intel_pt_snapshot_ref    *snapshot_refs;
  62         size_t                          priv_size;
  63 };
  64
  65 static int intel_pt_parse_terms_with_default(struct list_head *formats,
  66                                              const char *str,
  67                                              u64 *config)
  68 {
  69         struct list_head *terms;
  70         struct perf_event_attr attr = { .size = 0, };
  71         int err;
  72
  73         terms = malloc(sizeof(struct list_head));
  74         if (!terms)
  75                 return -ENOMEM;
  76
  77         INIT_LIST_HEAD(terms);
  78
  79         err = parse_events_terms(terms, str);
  80         if (err)
  81                 goto out_free;
  82
  83         attr.config = *config;
  84         err = perf_pmu__config_terms(formats, &attr, terms, true, NULL);
  85         if (err)
  86                 goto out_free;
  87
  88         *config = attr.config;
  89 out_free:
  90         parse_events_terms__delete(terms);
  91         return err;
  92 }
  93
  94 static int intel_pt_parse_terms(struct list_head *formats, const char *str,
  95                                 u64 *config)
  96 {
  97         *config = 0;
  98         return intel_pt_parse_terms_with_default(formats, str, config);
  99 }
 100
 101 static u64 intel_pt_masked_bits(u64 mask, u64 bits)
 102 {
 103         const u64 top_bit = 1ULL << 63;
 104         u64 res = 0;
 105         int i;
 106
 107         for (i = 0; i < 64; i++) {
 108                 if (mask & top_bit) {
 109                         res <<= 1;
 110                         if (bits & top_bit)
 111                                 res |= 1;
 112                 }
 113                 mask <<= 1;
 114                 bits <<= 1;
 115         }
 116
 117         return res;
 118 }
 119
 120 static int intel_pt_read_config(struct perf_pmu *intel_pt_pmu, const char *str,
 121                                 struct perf_evlist *evlist, u64 *res)
 122 {
 123         struct perf_evsel *evsel;
 124         u64 mask;
 125
 126         *res = 0;
 127
 128         mask = perf_pmu__format_bits(&intel_pt_pmu->format, str);
 129         if (!mask)
 130                 return -EINVAL;
 131
 132         evlist__for_each_entry(evlist, evsel) {
 133                 if (evsel->attr.type == intel_pt_pmu->type) {
 134                         *res = intel_pt_masked_bits(mask, evsel->attr.config);
 135                         return 0;
 136                 }
 137         }
 138
 139         return -EINVAL;
 140 }
 141
 142 static size_t intel_pt_psb_period(struct perf_pmu *intel_pt_pmu,
 143                                   struct perf_evlist *evlist)
 144 {
 145         u64 val;
 146         int err, topa_multiple_entries;
 147         size_t psb_period;
 148
 149         if (perf_pmu__scan_file(intel_pt_pmu, "caps/topa_multiple_entries",
 150                                 "%d", &topa_multiple_entries) != 1)
 151                 topa_multiple_entries = 0;
 152
 153         /*
 154          * Use caps/topa_multiple_entries to indicate early hardware that had
 155          * extra frequent PSBs.
 156          */
 157         if (!topa_multiple_entries) {
 158                 psb_period = 256;
 159                 goto out;
 160         }
 161
 162         err = intel_pt_read_config(intel_pt_pmu, "psb_period", evlist, &val);
 163         if (err)
 164                 val = 0;
 165
 166         psb_period = 1 << (val + 11);
 167 out:
 168         pr_debug2("%s psb_period %zu\n", intel_pt_pmu->name, psb_period);
 169         return psb_period;
 170 }
 171
 172 static int intel_pt_pick_bit(int bits, int target)
 173 {
 174         int pos, pick = -1;
 175
 176         for (pos = 0; bits; bits >>= 1, pos++) {
 177                 if (bits & 1) {
 178                         if (pos <= target || pick < 0)
 179                                 pick = pos;
 180                         if (pos >= target)
 181                                 break;
 182                 }
 183         }
 184
 185         return pick;
 186 }
 187
 188 static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu)
 189 {
 190         char buf[256];
 191         int mtc, mtc_periods = 0, mtc_period;
 192         int psb_cyc, psb_periods, psb_period;
 193         int pos = 0;
 194         u64 config;
 195         char c;
 196
 197         pos += scnprintf(buf + pos, sizeof(buf) - pos, "tsc");
 198
 199         if (perf_pmu__scan_file(intel_pt_pmu, "caps/mtc", "%d",
 200                                 &mtc) != 1)
 201                 mtc = 1;
 202
 203         if (mtc) {
 204                 if (perf_pmu__scan_file(intel_pt_pmu, "caps/mtc_periods", "%x",
 205                                         &mtc_periods) != 1)
 206                         mtc_periods = 0;
 207                 if (mtc_periods) {
 208                         mtc_period = intel_pt_pick_bit(mtc_periods, 3);
 209                         pos += scnprintf(buf + pos, sizeof(buf) - pos,
 210                                          ",mtc,mtc_period=%d", mtc_period);
 211                 }
 212         }
 213
 214         if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_cyc", "%d",
 215                                 &psb_cyc) != 1)
 216                 psb_cyc = 1;
 217
 218         if (psb_cyc && mtc_periods) {
 219                 if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_periods", "%x",
 220                                         &psb_periods) != 1)
 221                         psb_periods = 0;
 222                 if (psb_periods) {
 223                         psb_period = intel_pt_pick_bit(psb_periods, 3);
 224                         pos += scnprintf(buf + pos, sizeof(buf) - pos,
 225                                          ",psb_period=%d", psb_period);
 226                 }
 227         }
 228
 229         if (perf_pmu__scan_file(intel_pt_pmu, "format/pt", "%c", &c) == 1 &&
 230             perf_pmu__scan_file(intel_pt_pmu, "format/branch", "%c", &c) == 1)
 231                 pos += scnprintf(buf + pos, sizeof(buf) - pos, ",pt,branch");
 232
 233         pr_debug2("%s default config: %s\n", intel_pt_pmu->name, buf);
 234
 235         intel_pt_parse_terms(&intel_pt_pmu->format, buf, &config);
 236
 237         return config;
 238 }
 239
 240 static int intel_pt_parse_snapshot_options(struct auxtrace_record *itr,
 241                                            struct record_opts *opts,
 242                                            const char *str)
 243 {
 244         struct intel_pt_recording *ptr =
 245                         container_of(itr, struct intel_pt_recording, itr);
 246         unsigned long long snapshot_size = 0;
 247         char *endptr;
 248
 249         if (str) {
 250                 snapshot_size = strtoull(str, &endptr, 0);
 251                 if (*endptr || snapshot_size > SIZE_MAX)
 252                         return -1;
 253         }
 254
 255         opts->auxtrace_snapshot_mode = true;
 256         opts->auxtrace_snapshot_size = snapshot_size;
 257
 258         ptr->snapshot_size = snapshot_size;
 259
 260         return 0;
 261 }
 262
 263 struct perf_event_attr *
 264 intel_pt_pmu_default_config(struct perf_pmu *intel_pt_pmu)
 265 {
 266         struct perf_event_attr *attr;
 267
 268         attr = zalloc(sizeof(struct perf_event_attr));
 269         if (!attr)
 270                 return NULL;
 271
 272         attr->config = intel_pt_default_config(intel_pt_pmu);
 273
 274         intel_pt_pmu->selectable = true;
 275
 276         return attr;
 277 }
 278
 279 static const char *intel_pt_find_filter(struct perf_evlist *evlist,
 280                                         struct perf_pmu *intel_pt_pmu)
 281 {
 282         struct perf_evsel *evsel;
 283
 284         evlist__for_each_entry(evlist, evsel) {
 285                 if (evsel->attr.type == intel_pt_pmu->type)
 286                         return evsel->filter;
 287         }
 288
 289         return NULL;
 290 }
 291
 292 static size_t intel_pt_filter_bytes(const char *filter)
 293 {
 294         size_t len = filter ? strlen(filter) : 0;
 295
 296         return len ? roundup(len + 1, 8) : 0;
 297 }
 298
 299 static size_t
 300 intel_pt_info_priv_size(struct auxtrace_record *itr, struct perf_evlist *evlist)
 301 {
 302         struct intel_pt_recording *ptr =
 303                         container_of(itr, struct intel_pt_recording, itr);
 304         const char *filter = intel_pt_find_filter(evlist, ptr->intel_pt_pmu);
 305
 306         ptr->priv_size = (INTEL_PT_AUXTRACE_PRIV_MAX * sizeof(u64)) +
 307                          intel_pt_filter_bytes(filter);
 308
 309         return ptr->priv_size;
 310 }
 311
 312 static void intel_pt_tsc_ctc_ratio(u32 *n, u32 *d)
 313 {
 314         unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
 315
 316         __get_cpuid(0x15, &eax, &ebx, &ecx, &edx);
 317         *n = ebx;
 318         *d = eax;
 319 }
 320
 321 static int intel_pt_info_fill(struct auxtrace_record *itr,
 322                               struct perf_session *session,
 323                               struct auxtrace_info_event *auxtrace_info,
 324                               size_t priv_size)
 325 {
 326         struct intel_pt_recording *ptr =
 327                         container_of(itr, struct intel_pt_recording, itr);
 328         struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
 329         struct perf_event_mmap_page *pc;
 330         struct perf_tsc_conversion tc = { .time_mult = 0, };
 331         bool cap_user_time_zero = false, per_cpu_mmaps;
 332         u64 tsc_bit, mtc_bit, mtc_freq_bits, cyc_bit, noretcomp_bit;
 333         u32 tsc_ctc_ratio_n, tsc_ctc_ratio_d;
 334         unsigned long max_non_turbo_ratio;
 335         size_t filter_str_len;
 336         const char *filter;
 337         u64 *info;
 338         int err;
 339
 340         if (priv_size != ptr->priv_size)
 341                 return -EINVAL;
 342
 343         intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &tsc_bit);
 344         intel_pt_parse_terms(&intel_pt_pmu->format, "noretcomp",
 345                              &noretcomp_bit);
 346         intel_pt_parse_terms(&intel_pt_pmu->format, "mtc", &mtc_bit);
 347         mtc_freq_bits = perf_pmu__format_bits(&intel_pt_pmu->format,
 348                                               "mtc_period");
 349         intel_pt_parse_terms(&intel_pt_pmu->format, "cyc", &cyc_bit);
 350
 351         intel_pt_tsc_ctc_ratio(&tsc_ctc_ratio_n, &tsc_ctc_ratio_d);
 352
 353         if (perf_pmu__scan_file(intel_pt_pmu, "max_nonturbo_ratio",
 354                                 "%lu", &max_non_turbo_ratio) != 1)
 355                 max_non_turbo_ratio = 0;
 356
 357         filter = intel_pt_find_filter(session->evlist, ptr->intel_pt_pmu);
 358         filter_str_len = filter ? strlen(filter) : 0;
 359
 360         if (!session->evlist->nr_mmaps)
 361                 return -EINVAL;
 362
 363         pc = session->evlist->mmap[0].base;
 364         if (pc) {
 365                 err = perf_read_tsc_conversion(pc, &tc);
 366                 if (err) {
 367                         if (err != -EOPNOTSUPP)
 368                                 return err;
 369                 } else {
 370                         cap_user_time_zero = tc.time_mult != 0;
 371                 }
 372                 if (!cap_user_time_zero)
 373                         ui__warning("Intel Processor Trace: TSC not available\n");
 374         }
 375
 376         per_cpu_mmaps = !cpu_map__empty(session->evlist->cpus);
 377
 378         auxtrace_info->type = PERF_AUXTRACE_INTEL_PT;
 379         auxtrace_info->priv[INTEL_PT_PMU_TYPE] = intel_pt_pmu->type;
 380         auxtrace_info->priv[INTEL_PT_TIME_SHIFT] = tc.time_shift;
 381         auxtrace_info->priv[INTEL_PT_TIME_MULT] = tc.time_mult;
 382         auxtrace_info->priv[INTEL_PT_TIME_ZERO] = tc.time_zero;
 383         auxtrace_info->priv[INTEL_PT_CAP_USER_TIME_ZERO] = cap_user_time_zero;
 384         auxtrace_info->priv[INTEL_PT_TSC_BIT] = tsc_bit;
 385         auxtrace_info->priv[INTEL_PT_NORETCOMP_BIT] = noretcomp_bit;
 386         auxtrace_info->priv[INTEL_PT_HAVE_SCHED_SWITCH] = ptr->have_sched_switch;
 387         auxtrace_info->priv[INTEL_PT_SNAPSHOT_MODE] = ptr->snapshot_mode;
 388         auxtrace_info->priv[INTEL_PT_PER_CPU_MMAPS] = per_cpu_mmaps;
 389         auxtrace_info->priv[INTEL_PT_MTC_BIT] = mtc_bit;
 390         auxtrace_info->priv[INTEL_PT_MTC_FREQ_BITS] = mtc_freq_bits;
 391         auxtrace_info->priv[INTEL_PT_TSC_CTC_N] = tsc_ctc_ratio_n;
 392         auxtrace_info->priv[INTEL_PT_TSC_CTC_D] = tsc_ctc_ratio_d;
 393         auxtrace_info->priv[INTEL_PT_CYC_BIT] = cyc_bit;
 394         auxtrace_info->priv[INTEL_PT_MAX_NONTURBO_RATIO] = max_non_turbo_ratio;
 395         auxtrace_info->priv[INTEL_PT_FILTER_STR_LEN] = filter_str_len;
 396
 397         info = &auxtrace_info->priv[INTEL_PT_FILTER_STR_LEN] + 1;
 398
 399         if (filter_str_len) {
 400                 size_t len = intel_pt_filter_bytes(filter);
 401
 402                 strncpy((char *)info, filter, len);
 403                 info += len >> 3;
 404         }
 405
 406         return 0;
 407 }
 408
 409 static int intel_pt_track_switches(struct perf_evlist *evlist)
 410 {
 411         const char *sched_switch = "sched:sched_switch";
 412         struct perf_evsel *evsel;
 413         int err;
 414
 415         if (!perf_evlist__can_select_event(evlist, sched_switch))
 416                 return -EPERM;
 417
 418         err = parse_events(evlist, sched_switch, NULL);
 419         if (err) {
 420                 pr_debug2("%s: failed to parse %s, error %d\n",
 421                           __func__, sched_switch, err);
 422                 return err;
 423         }
 424
 425         evsel = perf_evlist__last(evlist);
 426
 427         perf_evsel__set_sample_bit(evsel, CPU);
 428         perf_evsel__set_sample_bit(evsel, TIME);
 429
 430         evsel->system_wide = true;
 431         evsel->no_aux_samples = true;
 432         evsel->immediate = true;
 433
 434         return 0;
 435 }
 436
 437 static void intel_pt_valid_str(char *str, size_t len, u64 valid)
 438 {
 439         unsigned int val, last = 0, state = 1;
 440         int p = 0;
 441
 442         str[0] = '\0';
 443
 444         for (val = 0; val <= 64; val++, valid >>= 1) {
 445                 if (valid & 1) {
 446                         last = val;
 447                         switch (state) {
 448                         case 0:
 449                                 p += scnprintf(str + p, len - p, ",");
 450                                 /* Fall through */
 451                         case 1:
 452                                 p += scnprintf(str + p, len - p, "%u", val);
 453                                 state = 2;
 454                                 break;
 455                         case 2:
 456                                 state = 3;
 457                                 break;
 458                         case 3:
 459                                 state = 4;
 460                                 break;
 461                         default:
 462                                 break;
 463                         }
 464                 } else {
 465                         switch (state) {
 466                         case 3:
 467                                 p += scnprintf(str + p, len - p, ",%u", last);
 468                                 state = 0;
 469                                 break;
 470                         case 4:
 471                                 p += scnprintf(str + p, len - p, "-%u", last);
 472                                 state = 0;
 473                                 break;
 474                         default:
 475                                 break;
 476                         }
 477                         if (state != 1)
 478                                 state = 0;
 479                 }
 480         }
 481 }
 482
 483 static int intel_pt_val_config_term(struct perf_pmu *intel_pt_pmu,
 484                                     const char *caps, const char *name,
 485                                     const char *supported, u64 config)
 486 {
 487         char valid_str[256];
 488         unsigned int shift;
 489         unsigned long long valid;
 490         u64 bits;
 491         int ok;
 492
 493         if (perf_pmu__scan_file(intel_pt_pmu, caps, "%llx", &valid) != 1)
 494                 valid = 0;
 495
 496         if (supported &&
 497             perf_pmu__scan_file(intel_pt_pmu, supported, "%d", &ok) == 1 && !ok)
 498                 valid = 0;
 499
 500         valid |= 1;
 501
 502         bits = perf_pmu__format_bits(&intel_pt_pmu->format, name);
 503
 504         config &= bits;
 505
 506         for (shift = 0; bits && !(bits & 1); shift++)
 507                 bits >>= 1;
 508
 509         config >>= shift;
 510
 511         if (config > 63)
 512                 goto out_err;
 513
 514         if (valid & (1 << config))
 515                 return 0;
 516 out_err:
 517         intel_pt_valid_str(valid_str, sizeof(valid_str), valid);
 518         pr_err("Invalid %s for %s. Valid values are: %s\n",
 519                name, INTEL_PT_PMU_NAME, valid_str);
 520         return -EINVAL;
 521 }
 522
 523 static int intel_pt_validate_config(struct perf_pmu *intel_pt_pmu,
 524                                     struct perf_evsel *evsel)
 525 {
 526         int err;
 527         char c;
 528
 529         if (!evsel)
 530                 return 0;
 531
 532         /*
 533          * If supported, force pass-through config term (pt=1) even if user
 534          * sets pt=0, which avoids senseless kernel errors.
 535          */
 536         if (perf_pmu__scan_file(intel_pt_pmu, "format/pt", "%c", &c) == 1 &&
 537             !(evsel->attr.config & 1)) {
 538                 pr_warning("pt=0 doesn't make sense, forcing pt=1\n");
 539                 evsel->attr.config |= 1;
 540         }
 541
 542         err = intel_pt_val_config_term(intel_pt_pmu, "caps/cycle_thresholds",
 543                                        "cyc_thresh", "caps/psb_cyc",
 544                                        evsel->attr.config);
 545         if (err)
 546                 return err;
 547
 548         err = intel_pt_val_config_term(intel_pt_pmu, "caps/mtc_periods",
 549                                        "mtc_period", "caps/mtc",
 550                                        evsel->attr.config);
 551         if (err)
 552                 return err;
 553
 554         return intel_pt_val_config_term(intel_pt_pmu, "caps/psb_periods",
 555                                         "psb_period", "caps/psb_cyc",
 556                                         evsel->attr.config);
 557 }
 558
 559 static int intel_pt_recording_options(struct auxtrace_record *itr,
 560                                       struct perf_evlist *evlist,
 561                                       struct record_opts *opts)
 562 {
 563         struct intel_pt_recording *ptr =
 564                         container_of(itr, struct intel_pt_recording, itr);
 565         struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
 566         bool have_timing_info, need_immediate = false;
 567         struct perf_evsel *evsel, *intel_pt_evsel = NULL;
 568         const struct cpu_map *cpus = evlist->cpus;
 569         bool privileged = geteuid() == 0 || perf_event_paranoid() < 0;
 570         u64 tsc_bit;
 571         int err;
 572
 573         ptr->evlist = evlist;
 574         ptr->snapshot_mode = opts->auxtrace_snapshot_mode;
 575
 576         evlist__for_each_entry(evlist, evsel) {
 577                 if (evsel->attr.type == intel_pt_pmu->type) {
 578                         if (intel_pt_evsel) {
 579                                 pr_err("There may be only one " INTEL_PT_PMU_NAME " event\n");
 580                                 return -EINVAL;
 581                         }
 582                         evsel->attr.freq = 0;
 583                         evsel->attr.sample_period = 1;
 584                         intel_pt_evsel = evsel;
 585                         opts->full_auxtrace = true;
 586                 }
 587         }
 588
 589         if (opts->auxtrace_snapshot_mode && !opts->full_auxtrace) {
 590                 pr_err("Snapshot mode (-S option) requires " INTEL_PT_PMU_NAME " PMU event (-e " INTEL_PT_PMU_NAME ")\n");
 591                 return -EINVAL;
 592         }
 593
 594         if (opts->use_clockid) {
 595                 pr_err("Cannot use clockid (-k option) with " INTEL_PT_PMU_NAME "\n");
 596                 return -EINVAL;
 597         }
 598
 599         if (!opts->full_auxtrace)
 600                 return 0;
 601
 602         err = intel_pt_validate_config(intel_pt_pmu, intel_pt_evsel);
 603         if (err)
 604                 return err;
 605
 606         /* Set default sizes for snapshot mode */
 607         if (opts->auxtrace_snapshot_mode) {
 608                 size_t psb_period = intel_pt_psb_period(intel_pt_pmu, evlist);
 609
 610                 if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) {
 611                         if (privileged) {
 612                                 opts->auxtrace_mmap_pages = MiB(4) / page_size;
 613                         } else {
 614                                 opts->auxtrace_mmap_pages = KiB(128) / page_size;
 615                                 if (opts->mmap_pages == UINT_MAX)
 616                                         opts->mmap_pages = KiB(256) / page_size;
 617                         }
 618                 } else if (!opts->auxtrace_mmap_pages && !privileged &&
 619                            opts->mmap_pages == UINT_MAX) {
 620                         opts->mmap_pages = KiB(256) / page_size;
 621                 }
 622                 if (!opts->auxtrace_snapshot_size)
 623                         opts->auxtrace_snapshot_size =
 624                                 opts->auxtrace_mmap_pages * (size_t)page_size;
 625                 if (!opts->auxtrace_mmap_pages) {
 626                         size_t sz = opts->auxtrace_snapshot_size;
 627
 628                         sz = round_up(sz, page_size) / page_size;
 629                         opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
 630                 }
 631                 if (opts->auxtrace_snapshot_size >
 632                                 opts->auxtrace_mmap_pages * (size_t)page_size) {
 633                         pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
 634                                opts->auxtrace_snapshot_size,
 635                                opts->auxtrace_mmap_pages * (size_t)page_size);
 636                         return -EINVAL;
 637                 }
 638                 if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) {
 639                         pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
 640                         return -EINVAL;
 641                 }
 642                 pr_debug2("Intel PT snapshot size: %zu\n",
 643                           opts->auxtrace_snapshot_size);
 644                 if (psb_period &&
 645                     opts->auxtrace_snapshot_size <= psb_period +
 646                                                   INTEL_PT_PSB_PERIOD_NEAR)
 647                         ui__warning("Intel PT snapshot size (%zu) may be too small for PSB period (%zu)\n",
 648                                     opts->auxtrace_snapshot_size, psb_period);
 649         }
 650
 651         /* Set default sizes for full trace mode */
 652         if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
 653                 if (privileged) {
 654                         opts->auxtrace_mmap_pages = MiB(4) / page_size;
 655                 } else {
 656                         opts->auxtrace_mmap_pages = KiB(128) / page_size;
 657                         if (opts->mmap_pages == UINT_MAX)
 658                                 opts->mmap_pages = KiB(256) / page_size;
 659                 }
 660         }
 661
 662         /* Validate auxtrace_mmap_pages */
 663         if (opts->auxtrace_mmap_pages) {
 664                 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
 665                 size_t min_sz;
 666
 667                 if (opts->auxtrace_snapshot_mode)
 668                         min_sz = KiB(4);
 669                 else
 670                         min_sz = KiB(8);
 671
 672                 if (sz < min_sz || !is_power_of_2(sz)) {
 673                         pr_err("Invalid mmap size for Intel Processor Trace: must be at least %zuKiB and a power of 2\n",
 674                                min_sz / 1024);
 675                         return -EINVAL;
 676                 }
 677         }
 678
 679         intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &tsc_bit);
 680
 681         if (opts->full_auxtrace && (intel_pt_evsel->attr.config & tsc_bit))
 682                 have_timing_info = true;
 683         else
 684                 have_timing_info = false;
 685
 686         /*
 687          * Per-cpu recording needs sched_switch events to distinguish different
 688          * threads.
 689          */
 690         if (have_timing_info && !cpu_map__empty(cpus)) {
 691                 if (perf_can_record_switch_events()) {
 692                         bool cpu_wide = !target__none(&opts->target) &&
 693                                         !target__has_task(&opts->target);
 694
 695                         if (!cpu_wide && perf_can_record_cpu_wide()) {
 696                                 struct perf_evsel *switch_evsel;
 697
 698                                 err = parse_events(evlist, "dummy:u", NULL);
 699                                 if (err)
 700                                         return err;
 701
 702                                 switch_evsel = perf_evlist__last(evlist);
 703
 704                                 switch_evsel->attr.freq = 0;
 705                                 switch_evsel->attr.sample_period = 1;
 706                                 switch_evsel->attr.context_switch = 1;
 707
 708                                 switch_evsel->system_wide = true;
 709                                 switch_evsel->no_aux_samples = true;
 710                                 switch_evsel->immediate = true;
 711
 712                                 perf_evsel__set_sample_bit(switch_evsel, TID);
 713                                 perf_evsel__set_sample_bit(switch_evsel, TIME);
 714                                 perf_evsel__set_sample_bit(switch_evsel, CPU);
 715                                 perf_evsel__reset_sample_bit(switch_evsel, BRANCH_STACK);
 716
 717                                 opts->record_switch_events = false;
 718                                 ptr->have_sched_switch = 3;
 719                         } else {
 720                                 opts->record_switch_events = true;
 721                                 need_immediate = true;
 722                                 if (cpu_wide)
 723                                         ptr->have_sched_switch = 3;
 724                                 else
 725                                         ptr->have_sched_switch = 2;
 726                         }
 727                 } else {
 728                         err = intel_pt_track_switches(evlist);
 729                         if (err == -EPERM)
 730                                 pr_debug2("Unable to select sched:sched_switch\n");
 731                         else if (err)
 732                                 return err;
 733                         else
 734                                 ptr->have_sched_switch = 1;
 735                 }
 736         }
 737
 738         if (intel_pt_evsel) {
 739                 /*
 740                  * To obtain the auxtrace buffer file descriptor, the auxtrace
 741                  * event must come first.
 742                  */
 743                 perf_evlist__to_front(evlist, intel_pt_evsel);
 744                 /*
 745                  * In the case of per-cpu mmaps, we need the CPU on the
 746                  * AUX event.
 747                  */
 748                 if (!cpu_map__empty(cpus))
 749                         perf_evsel__set_sample_bit(intel_pt_evsel, CPU);
 750         }
 751
 752         /* Add dummy event to keep tracking */
 753         if (opts->full_auxtrace) {
 754                 struct perf_evsel *tracking_evsel;
 755
 756                 err = parse_events(evlist, "dummy:u", NULL);
 757                 if (err)
 758                         return err;
 759
 760                 tracking_evsel = perf_evlist__last(evlist);
 761
 762                 perf_evlist__set_tracking_event(evlist, tracking_evsel);
 763
 764                 tracking_evsel->attr.freq = 0;
 765                 tracking_evsel->attr.sample_period = 1;
 766
 767                 tracking_evsel->no_aux_samples = true;
 768                 if (need_immediate)
 769                         tracking_evsel->immediate = true;
 770
 771                 /* In per-cpu case, always need the time of mmap events etc */
 772                 if (!cpu_map__empty(cpus)) {
 773                         perf_evsel__set_sample_bit(tracking_evsel, TIME);
 774                         /* And the CPU for switch events */
 775                         perf_evsel__set_sample_bit(tracking_evsel, CPU);
 776                 }
 777                 perf_evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK);
 778         }
 779
 780         /*
 781          * Warn the user when we do not have enough information to decode i.e.
 782          * per-cpu with no sched_switch (except workload-only).
 783          */
 784         if (!ptr->have_sched_switch && !cpu_map__empty(cpus) &&
 785             !target__none(&opts->target))
 786                 ui__warning("Intel Processor Trace decoding will not be possible except for kernel tracing!\n");
 787
 788         return 0;
 789 }
 790
 791 static int intel_pt_snapshot_start(struct auxtrace_record *itr)
 792 {
 793         struct intel_pt_recording *ptr =
 794                         container_of(itr, struct intel_pt_recording, itr);
 795         struct perf_evsel *evsel;
 796
 797         evlist__for_each_entry(ptr->evlist, evsel) {
 798                 if (evsel->attr.type == ptr->intel_pt_pmu->type)
 799                         return perf_evsel__disable(evsel);
 800         }
 801         return -EINVAL;
 802 }
 803
 804 static int intel_pt_snapshot_finish(struct auxtrace_record *itr)
 805 {
 806         struct intel_pt_recording *ptr =
 807                         container_of(itr, struct intel_pt_recording, itr);
 808         struct perf_evsel *evsel;
 809
 810         evlist__for_each_entry(ptr->evlist, evsel) {
 811                 if (evsel->attr.type == ptr->intel_pt_pmu->type)
 812                         return perf_evsel__enable(evsel);
 813         }
 814         return -EINVAL;
 815 }
 816
 817 static int intel_pt_alloc_snapshot_refs(struct intel_pt_recording *ptr, int idx)
 818 {
 819         const size_t sz = sizeof(struct intel_pt_snapshot_ref);
 820         int cnt = ptr->snapshot_ref_cnt, new_cnt = cnt * 2;
 821         struct intel_pt_snapshot_ref *refs;
 822
 823         if (!new_cnt)
 824                 new_cnt = 16;
 825
 826         while (new_cnt <= idx)
 827                 new_cnt *= 2;
 828
 829         refs = calloc(new_cnt, sz);
 830         if (!refs)
 831                 return -ENOMEM;
 832
 833         memcpy(refs, ptr->snapshot_refs, cnt * sz);
 834
 835         ptr->snapshot_refs = refs;
 836         ptr->snapshot_ref_cnt = new_cnt;
 837
 838         return 0;
 839 }
 840
 841 static void intel_pt_free_snapshot_refs(struct intel_pt_recording *ptr)
 842 {
 843         int i;
 844
 845         for (i = 0; i < ptr->snapshot_ref_cnt; i++)
 846                 zfree(&ptr->snapshot_refs[i].ref_buf);
 847         zfree(&ptr->snapshot_refs);
 848 }
 849
 850 static void intel_pt_recording_free(struct auxtrace_record *itr)
 851 {
 852         struct intel_pt_recording *ptr =
 853                         container_of(itr, struct intel_pt_recording, itr);
 854
 855         intel_pt_free_snapshot_refs(ptr);
 856         free(ptr);
 857 }
 858
 859 static int intel_pt_alloc_snapshot_ref(struct intel_pt_recording *ptr, int idx,
 860                                        size_t snapshot_buf_size)
 861 {
 862         size_t ref_buf_size = ptr->snapshot_ref_buf_size;
 863         void *ref_buf;
 864
 865         ref_buf = zalloc(ref_buf_size);
 866         if (!ref_buf)
 867                 return -ENOMEM;
 868
 869         ptr->snapshot_refs[idx].ref_buf = ref_buf;
 870         ptr->snapshot_refs[idx].ref_offset = snapshot_buf_size - ref_buf_size;
 871
 872         return 0;
 873 }
 874
 875 static size_t intel_pt_snapshot_ref_buf_size(struct intel_pt_recording *ptr,
 876                                              size_t snapshot_buf_size)
 877 {
 878         const size_t max_size = 256 * 1024;
 879         size_t buf_size = 0, psb_period;
 880
 881         if (ptr->snapshot_size <= 64 * 1024)
 882                 return 0;
 883
 884         psb_period = intel_pt_psb_period(ptr->intel_pt_pmu, ptr->evlist);
 885         if (psb_period)
 886                 buf_size = psb_period * 2;
 887
 888         if (!buf_size || buf_size > max_size)
 889                 buf_size = max_size;
 890
 891         if (buf_size >= snapshot_buf_size)
 892                 return 0;
 893
 894         if (buf_size >= ptr->snapshot_size / 2)
 895                 return 0;
 896
 897         return buf_size;
 898 }
 899
 900 static int intel_pt_snapshot_init(struct intel_pt_recording *ptr,
 901                                   size_t snapshot_buf_size)
 902 {
 903         if (ptr->snapshot_init_done)
 904                 return 0;
 905
 906         ptr->snapshot_init_done = true;
 907
 908         ptr->snapshot_ref_buf_size = intel_pt_snapshot_ref_buf_size(ptr,
 909                                                         snapshot_buf_size);
 910
 911         return 0;
 912 }
 913
 914 /**
 915  * intel_pt_compare_buffers - compare bytes in a buffer to a circular buffer.
 916  * @buf1: first buffer
 917  * @compare_size: number of bytes to compare
 918  * @buf2: second buffer (a circular buffer)
 919  * @offs2: offset in second buffer
 920  * @buf2_size: size of second buffer
 921  *
 922  * The comparison allows for the possibility that the bytes to compare in the
 923  * circular buffer are not contiguous.  It is assumed that @compare_size <=
 924  * @buf2_size.  This function returns %false if the bytes are identical, %true
 925  * otherwise.
 926  */
 927 static bool intel_pt_compare_buffers(void *buf1, size_t compare_size,
 928                                      void *buf2, size_t offs2, size_t buf2_size)
 929 {
 930         size_t end2 = offs2 + compare_size, part_size;
 931
 932         if (end2 <= buf2_size)
 933                 return memcmp(buf1, buf2 + offs2, compare_size);
 934
 935         part_size = end2 - buf2_size;
 936         if (memcmp(buf1, buf2 + offs2, part_size))
 937                 return true;
 938
 939         compare_size -= part_size;
 940
 941         return memcmp(buf1 + part_size, buf2, compare_size);
 942 }
 943
 944 static bool intel_pt_compare_ref(void *ref_buf, size_t ref_offset,
 945                                  size_t ref_size, size_t buf_size,
 946                                  void *data, size_t head)
 947 {
 948         size_t ref_end = ref_offset + ref_size;
 949
 950         if (ref_end > buf_size) {
 951                 if (head > ref_offset || head < ref_end - buf_size)
 952                         return true;
 953         } else if (head > ref_offset && head < ref_end) {
 954                 return true;
 955         }
 956
 957         return intel_pt_compare_buffers(ref_buf, ref_size, data, ref_offset,
 958                                         buf_size);
 959 }
 960
 961 static void intel_pt_copy_ref(void *ref_buf, size_t ref_size, size_t buf_size,
 962                               void *data, size_t head)
 963 {
 964         if (head >= ref_size) {
 965                 memcpy(ref_buf, data + head - ref_size, ref_size);
 966         } else {
 967                 memcpy(ref_buf, data, head);
 968                 ref_size -= head;
 969                 memcpy(ref_buf + head, data + buf_size - ref_size, ref_size);
 970         }
 971 }
 972
 973 static bool intel_pt_wrapped(struct intel_pt_recording *ptr, int idx,
 974                              struct auxtrace_mmap *mm, unsigned char *data,
 975                              u64 head)
 976 {
 977         struct intel_pt_snapshot_ref *ref = &ptr->snapshot_refs[idx];
 978         bool wrapped;
 979
 980         wrapped = intel_pt_compare_ref(ref->ref_buf, ref->ref_offset,
 981                                        ptr->snapshot_ref_buf_size, mm->len,
 982                                        data, head);
 983
 984         intel_pt_copy_ref(ref->ref_buf, ptr->snapshot_ref_buf_size, mm->len,
 985                           data, head);
 986
 987         return wrapped;
 988 }
 989
 990 static bool intel_pt_first_wrap(u64 *data, size_t buf_size)
 991 {
 992         int i, a, b;
 993
 994         b = buf_size >> 3;
 995         a = b - 512;
 996         if (a < 0)
 997                 a = 0;
 998
 999         for (i = a; i < b; i++) {
1000                 if (data[i])
1001                         return true;
1002         }
1003
1004         return false;
1005 }
1006
1007 static int intel_pt_find_snapshot(struct auxtrace_record *itr, int idx,
1008                                   struct auxtrace_mmap *mm, unsigned char *data,
1009                                   u64 *head, u64 *old)
1010 {
1011         struct intel_pt_recording *ptr =
1012                         container_of(itr, struct intel_pt_recording, itr);
1013         bool wrapped;
1014         int err;
1015
1016         pr_debug3("%s: mmap index %d old head %zu new head %zu\n",
1017                   __func__, idx, (size_t)*old, (size_t)*head);
1018
1019         err = intel_pt_snapshot_init(ptr, mm->len);
1020         if (err)
1021                 goto out_err;
1022
1023         if (idx >= ptr->snapshot_ref_cnt) {
1024                 err = intel_pt_alloc_snapshot_refs(ptr, idx);
1025                 if (err)
1026                         goto out_err;
1027         }
1028
1029         if (ptr->snapshot_ref_buf_size) {
1030                 if (!ptr->snapshot_refs[idx].ref_buf) {
1031                         err = intel_pt_alloc_snapshot_ref(ptr, idx, mm->len);
1032                         if (err)
1033                                 goto out_err;
1034                 }
1035                 wrapped = intel_pt_wrapped(ptr, idx, mm, data, *head);
1036         } else {
1037                 wrapped = ptr->snapshot_refs[idx].wrapped;
1038                 if (!wrapped && intel_pt_first_wrap((u64 *)data, mm->len)) {
1039                         ptr->snapshot_refs[idx].wrapped = true;
1040                         wrapped = true;
1041                 }
1042         }
1043
1044         /*
1045          * In full trace mode 'head' continually increases.  However in snapshot
1046          * mode 'head' is an offset within the buffer.  Here 'old' and 'head'
1047          * are adjusted to match the full trace case which expects that 'old' is
1048          * always less than 'head'.
1049          */
1050         if (wrapped) {
1051                 *old = *head;
1052                 *head += mm->len;
1053         } else {
1054                 if (mm->mask)
1055                         *old &= mm->mask;
1056                 else
1057                         *old %= mm->len;
1058                 if (*old > *head)
1059                         *head += mm->len;
1060         }
1061
1062         pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n",
1063                   __func__, wrapped ? "" : "not ", (size_t)*old, (size_t)*head);
1064
1065         return 0;
1066
1067 out_err:
1068         pr_err("%s: failed, error %d\n", __func__, err);
1069         return err;
1070 }
1071
1072 static u64 intel_pt_reference(struct auxtrace_record *itr __maybe_unused)
1073 {
1074         return rdtsc();
1075 }
1076
1077 static int intel_pt_read_finish(struct auxtrace_record *itr, int idx)
1078 {
1079         struct intel_pt_recording *ptr =
1080                         container_of(itr, struct intel_pt_recording, itr);
1081         struct perf_evsel *evsel;
1082
1083         evlist__for_each_entry(ptr->evlist, evsel) {
1084                 if (evsel->attr.type == ptr->intel_pt_pmu->type)
1085                         return perf_evlist__enable_event_idx(ptr->evlist, evsel,
1086                                                              idx);
1087         }
1088         return -EINVAL;
1089 }
1090
1091 struct auxtrace_record *intel_pt_recording_init(int *err)
1092 {
1093         struct perf_pmu *intel_pt_pmu = perf_pmu__find(INTEL_PT_PMU_NAME);
1094         struct intel_pt_recording *ptr;
1095
1096         if (!intel_pt_pmu)
1097                 return NULL;
1098
1099         if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) {
1100                 *err = -errno;
1101                 return NULL;
1102         }
1103
1104         ptr = zalloc(sizeof(struct intel_pt_recording));
1105         if (!ptr) {
1106                 *err = -ENOMEM;
1107                 return NULL;
1108         }
1109
1110         ptr->intel_pt_pmu = intel_pt_pmu;
1111         ptr->itr.recording_options = intel_pt_recording_options;
1112         ptr->itr.info_priv_size = intel_pt_info_priv_size;
1113         ptr->itr.info_fill = intel_pt_info_fill;
1114         ptr->itr.free = intel_pt_recording_free;
1115         ptr->itr.snapshot_start = intel_pt_snapshot_start;
1116         ptr->itr.snapshot_finish = intel_pt_snapshot_finish;
1117         ptr->itr.find_snapshot = intel_pt_find_snapshot;
1118         ptr->itr.parse_snapshot_options = intel_pt_parse_snapshot_options;
1119         ptr->itr.reference = intel_pt_reference;
1120         ptr->itr.read_finish = intel_pt_read_finish;
1121         return &ptr->itr;
1122 }