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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * intel_pt.c: Intel Processor Trace support
   4  * Copyright (c) 2013-2015, Intel Corporation.
   5  */
   6
   7 #include <errno.h>
   8 #include <stdbool.h>
   9 #include <linux/kernel.h>
  10 #include <linux/types.h>
  11 #include <linux/bitops.h>
  12 #include <linux/log2.h>
  13 #include <linux/zalloc.h>
  14 #include <cpuid.h>
  15
  16 #include "../../../util/session.h"
  17 #include "../../../util/event.h"
  18 #include "../../../util/evlist.h"
  19 #include "../../../util/evsel.h"
  20 #include "../../../util/evsel_config.h"
  21 #include "../../../util/cpumap.h"
  22 #include "../../../util/mmap.h"
  23 #include <subcmd/parse-options.h>
  24 #include "../../../util/parse-events.h"
  25 #include "../../../util/pmu.h"
  26 #include "../../../util/debug.h"
  27 #include "../../../util/auxtrace.h"
  28 #include "../../../util/perf_api_probe.h"
  29 #include "../../../util/record.h"
  30 #include "../../../util/target.h"
  31 #include "../../../util/tsc.h"
  32 #include <internal/lib.h> // page_size
  33 #include "../../../util/intel-pt.h"
  34
  35 #define KiB(x) ((x) * 1024)
  36 #define MiB(x) ((x) * 1024 * 1024)
  37 #define KiB_MASK(x) (KiB(x) - 1)
  38 #define MiB_MASK(x) (MiB(x) - 1)
  39
  40 #define INTEL_PT_PSB_PERIOD_NEAR        256
  41
  42 struct intel_pt_snapshot_ref {
  43         void *ref_buf;
  44         size_t ref_offset;
  45         bool wrapped;
  46 };
  47
  48 struct intel_pt_recording {
  49         struct auxtrace_record          itr;
  50         struct perf_pmu                 *intel_pt_pmu;
  51         int                             have_sched_switch;
  52         struct evlist           *evlist;
  53         bool                            snapshot_mode;
  54         bool                            snapshot_init_done;
  55         size_t                          snapshot_size;
  56         size_t                          snapshot_ref_buf_size;
  57         int                             snapshot_ref_cnt;
  58         struct intel_pt_snapshot_ref    *snapshot_refs;
  59         size_t                          priv_size;
  60 };
  61
  62 static int intel_pt_parse_terms_with_default(const char *pmu_name,
  63                                              struct list_head *formats,
  64                                              const char *str,
  65                                              u64 *config)
  66 {
  67         struct list_head *terms;
  68         struct perf_event_attr attr = { .size = 0, };
  69         int err;
  70
  71         terms = malloc(sizeof(struct list_head));
  72         if (!terms)
  73                 return -ENOMEM;
  74
  75         INIT_LIST_HEAD(terms);
  76
  77         err = parse_events_terms(terms, str);
  78         if (err)
  79                 goto out_free;
  80
  81         attr.config = *config;
  82         err = perf_pmu__config_terms(pmu_name, formats, &attr, terms, true,
  83                                      NULL);
  84         if (err)
  85                 goto out_free;
  86
  87         *config = attr.config;
  88 out_free:
  89         parse_events_terms__delete(terms);
  90         return err;
  91 }
  92
  93 static int intel_pt_parse_terms(const char *pmu_name, struct list_head *formats,
  94                                 const char *str, u64 *config)
  95 {
  96         *config = 0;
  97         return intel_pt_parse_terms_with_default(pmu_name, formats, str,
  98                                                  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 evlist *evlist, u64 *res)
 122 {
 123         struct 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->core.attr.type == intel_pt_pmu->type) {
 134                         *res = intel_pt_masked_bits(mask, evsel->core.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 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->name, &intel_pt_pmu->format, buf,
 236                              &config);
 237
 238         return config;
 239 }
 240
 241 static int intel_pt_parse_snapshot_options(struct auxtrace_record *itr,
 242                                            struct record_opts *opts,
 243                                            const char *str)
 244 {
 245         struct intel_pt_recording *ptr =
 246                         container_of(itr, struct intel_pt_recording, itr);
 247         unsigned long long snapshot_size = 0;
 248         char *endptr;
 249
 250         if (str) {
 251                 snapshot_size = strtoull(str, &endptr, 0);
 252                 if (*endptr || snapshot_size > SIZE_MAX)
 253                         return -1;
 254         }
 255
 256         opts->auxtrace_snapshot_mode = true;
 257         opts->auxtrace_snapshot_size = snapshot_size;
 258
 259         ptr->snapshot_size = snapshot_size;
 260
 261         return 0;
 262 }
 263
 264 struct perf_event_attr *
 265 intel_pt_pmu_default_config(struct perf_pmu *intel_pt_pmu)
 266 {
 267         struct perf_event_attr *attr;
 268
 269         attr = zalloc(sizeof(struct perf_event_attr));
 270         if (!attr)
 271                 return NULL;
 272
 273         attr->config = intel_pt_default_config(intel_pt_pmu);
 274
 275         intel_pt_pmu->selectable = true;
 276
 277         return attr;
 278 }
 279
 280 static const char *intel_pt_find_filter(struct evlist *evlist,
 281                                         struct perf_pmu *intel_pt_pmu)
 282 {
 283         struct evsel *evsel;
 284
 285         evlist__for_each_entry(evlist, evsel) {
 286                 if (evsel->core.attr.type == intel_pt_pmu->type)
 287                         return evsel->filter;
 288         }
 289
 290         return NULL;
 291 }
 292
 293 static size_t intel_pt_filter_bytes(const char *filter)
 294 {
 295         size_t len = filter ? strlen(filter) : 0;
 296
 297         return len ? roundup(len + 1, 8) : 0;
 298 }
 299
 300 static size_t
 301 intel_pt_info_priv_size(struct auxtrace_record *itr, struct evlist *evlist)
 302 {
 303         struct intel_pt_recording *ptr =
 304                         container_of(itr, struct intel_pt_recording, itr);
 305         const char *filter = intel_pt_find_filter(evlist, ptr->intel_pt_pmu);
 306
 307         ptr->priv_size = (INTEL_PT_AUXTRACE_PRIV_MAX * sizeof(u64)) +
 308                          intel_pt_filter_bytes(filter);
 309         ptr->priv_size += sizeof(u64); /* Cap Event Trace */
 310
 311         return ptr->priv_size;
 312 }
 313
 314 static void intel_pt_tsc_ctc_ratio(u32 *n, u32 *d)
 315 {
 316         unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
 317
 318         __get_cpuid(0x15, &eax, &ebx, &ecx, &edx);
 319         *n = ebx;
 320         *d = eax;
 321 }
 322
 323 static int intel_pt_info_fill(struct auxtrace_record *itr,
 324                               struct perf_session *session,
 325                               struct perf_record_auxtrace_info *auxtrace_info,
 326                               size_t priv_size)
 327 {
 328         struct intel_pt_recording *ptr =
 329                         container_of(itr, struct intel_pt_recording, itr);
 330         struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
 331         struct perf_event_mmap_page *pc;
 332         struct perf_tsc_conversion tc = { .time_mult = 0, };
 333         bool cap_user_time_zero = false, per_cpu_mmaps;
 334         u64 tsc_bit, mtc_bit, mtc_freq_bits, cyc_bit, noretcomp_bit;
 335         u32 tsc_ctc_ratio_n, tsc_ctc_ratio_d;
 336         unsigned long max_non_turbo_ratio;
 337         size_t filter_str_len;
 338         const char *filter;
 339         int event_trace;
 340         __u64 *info;
 341         int err;
 342
 343         if (priv_size != ptr->priv_size)
 344                 return -EINVAL;
 345
 346         intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format,
 347                              "tsc", &tsc_bit);
 348         intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format,
 349                              "noretcomp", &noretcomp_bit);
 350         intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format,
 351                              "mtc", &mtc_bit);
 352         mtc_freq_bits = perf_pmu__format_bits(&intel_pt_pmu->format,
 353                                               "mtc_period");
 354         intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format,
 355                              "cyc", &cyc_bit);
 356
 357         intel_pt_tsc_ctc_ratio(&tsc_ctc_ratio_n, &tsc_ctc_ratio_d);
 358
 359         if (perf_pmu__scan_file(intel_pt_pmu, "max_nonturbo_ratio",
 360                                 "%lu", &max_non_turbo_ratio) != 1)
 361                 max_non_turbo_ratio = 0;
 362         if (perf_pmu__scan_file(intel_pt_pmu, "caps/event_trace",
 363                                 "%d", &event_trace) != 1)
 364                 event_trace = 0;
 365
 366         filter = intel_pt_find_filter(session->evlist, ptr->intel_pt_pmu);
 367         filter_str_len = filter ? strlen(filter) : 0;
 368
 369         if (!session->evlist->core.nr_mmaps)
 370                 return -EINVAL;
 371
 372         pc = session->evlist->mmap[0].core.base;
 373         if (pc) {
 374                 err = perf_read_tsc_conversion(pc, &tc);
 375                 if (err) {
 376                         if (err != -EOPNOTSUPP)
 377                                 return err;
 378                 } else {
 379                         cap_user_time_zero = tc.time_mult != 0;
 380                 }
 381                 if (!cap_user_time_zero)
 382                         ui__warning("Intel Processor Trace: TSC not available\n");
 383         }
 384
 385         per_cpu_mmaps = !perf_cpu_map__empty(session->evlist->core.cpus);
 386
 387         auxtrace_info->type = PERF_AUXTRACE_INTEL_PT;
 388         auxtrace_info->priv[INTEL_PT_PMU_TYPE] = intel_pt_pmu->type;
 389         auxtrace_info->priv[INTEL_PT_TIME_SHIFT] = tc.time_shift;
 390         auxtrace_info->priv[INTEL_PT_TIME_MULT] = tc.time_mult;
 391         auxtrace_info->priv[INTEL_PT_TIME_ZERO] = tc.time_zero;
 392         auxtrace_info->priv[INTEL_PT_CAP_USER_TIME_ZERO] = cap_user_time_zero;
 393         auxtrace_info->priv[INTEL_PT_TSC_BIT] = tsc_bit;
 394         auxtrace_info->priv[INTEL_PT_NORETCOMP_BIT] = noretcomp_bit;
 395         auxtrace_info->priv[INTEL_PT_HAVE_SCHED_SWITCH] = ptr->have_sched_switch;
 396         auxtrace_info->priv[INTEL_PT_SNAPSHOT_MODE] = ptr->snapshot_mode;
 397         auxtrace_info->priv[INTEL_PT_PER_CPU_MMAPS] = per_cpu_mmaps;
 398         auxtrace_info->priv[INTEL_PT_MTC_BIT] = mtc_bit;
 399         auxtrace_info->priv[INTEL_PT_MTC_FREQ_BITS] = mtc_freq_bits;
 400         auxtrace_info->priv[INTEL_PT_TSC_CTC_N] = tsc_ctc_ratio_n;
 401         auxtrace_info->priv[INTEL_PT_TSC_CTC_D] = tsc_ctc_ratio_d;
 402         auxtrace_info->priv[INTEL_PT_CYC_BIT] = cyc_bit;
 403         auxtrace_info->priv[INTEL_PT_MAX_NONTURBO_RATIO] = max_non_turbo_ratio;
 404         auxtrace_info->priv[INTEL_PT_FILTER_STR_LEN] = filter_str_len;
 405
 406         info = &auxtrace_info->priv[INTEL_PT_FILTER_STR_LEN] + 1;
 407
 408         if (filter_str_len) {
 409                 size_t len = intel_pt_filter_bytes(filter);
 410
 411                 strncpy((char *)info, filter, len);
 412                 info += len >> 3;
 413         }
 414
 415         *info++ = event_trace;
 416
 417         return 0;
 418 }
 419
 420 static int intel_pt_track_switches(struct evlist *evlist)
 421 {
 422         const char *sched_switch = "sched:sched_switch";
 423         struct evsel *evsel;
 424         int err;
 425
 426         if (!evlist__can_select_event(evlist, sched_switch))
 427                 return -EPERM;
 428
 429         err = parse_events(evlist, sched_switch, NULL);
 430         if (err) {
 431                 pr_debug2("%s: failed to parse %s, error %d\n",
 432                           __func__, sched_switch, err);
 433                 return err;
 434         }
 435
 436         evsel = evlist__last(evlist);
 437
 438         evsel__set_sample_bit(evsel, CPU);
 439         evsel__set_sample_bit(evsel, TIME);
 440
 441         evsel->core.system_wide = true;
 442         evsel->no_aux_samples = true;
 443         evsel->immediate = true;
 444
 445         return 0;
 446 }
 447
 448 static void intel_pt_valid_str(char *str, size_t len, u64 valid)
 449 {
 450         unsigned int val, last = 0, state = 1;
 451         int p = 0;
 452
 453         str[0] = '\0';
 454
 455         for (val = 0; val <= 64; val++, valid >>= 1) {
 456                 if (valid & 1) {
 457                         last = val;
 458                         switch (state) {
 459                         case 0:
 460                                 p += scnprintf(str + p, len - p, ",");
 461                                 /* Fall through */
 462                         case 1:
 463                                 p += scnprintf(str + p, len - p, "%u", val);
 464                                 state = 2;
 465                                 break;
 466                         case 2:
 467                                 state = 3;
 468                                 break;
 469                         case 3:
 470                                 state = 4;
 471                                 break;
 472                         default:
 473                                 break;
 474                         }
 475                 } else {
 476                         switch (state) {
 477                         case 3:
 478                                 p += scnprintf(str + p, len - p, ",%u", last);
 479                                 state = 0;
 480                                 break;
 481                         case 4:
 482                                 p += scnprintf(str + p, len - p, "-%u", last);
 483                                 state = 0;
 484                                 break;
 485                         default:
 486                                 break;
 487                         }
 488                         if (state != 1)
 489                                 state = 0;
 490                 }
 491         }
 492 }
 493
 494 static int intel_pt_val_config_term(struct perf_pmu *intel_pt_pmu,
 495                                     const char *caps, const char *name,
 496                                     const char *supported, u64 config)
 497 {
 498         char valid_str[256];
 499         unsigned int shift;
 500         unsigned long long valid;
 501         u64 bits;
 502         int ok;
 503
 504         if (perf_pmu__scan_file(intel_pt_pmu, caps, "%llx", &valid) != 1)
 505                 valid = 0;
 506
 507         if (supported &&
 508             perf_pmu__scan_file(intel_pt_pmu, supported, "%d", &ok) == 1 && !ok)
 509                 valid = 0;
 510
 511         valid |= 1;
 512
 513         bits = perf_pmu__format_bits(&intel_pt_pmu->format, name);
 514
 515         config &= bits;
 516
 517         for (shift = 0; bits && !(bits & 1); shift++)
 518                 bits >>= 1;
 519
 520         config >>= shift;
 521
 522         if (config > 63)
 523                 goto out_err;
 524
 525         if (valid & (1 << config))
 526                 return 0;
 527 out_err:
 528         intel_pt_valid_str(valid_str, sizeof(valid_str), valid);
 529         pr_err("Invalid %s for %s. Valid values are: %s\n",
 530                name, INTEL_PT_PMU_NAME, valid_str);
 531         return -EINVAL;
 532 }
 533
 534 static int intel_pt_validate_config(struct perf_pmu *intel_pt_pmu,
 535                                     struct evsel *evsel)
 536 {
 537         int err;
 538         char c;
 539
 540         if (!evsel)
 541                 return 0;
 542
 543         /*
 544          * If supported, force pass-through config term (pt=1) even if user
 545          * sets pt=0, which avoids senseless kernel errors.
 546          */
 547         if (perf_pmu__scan_file(intel_pt_pmu, "format/pt", "%c", &c) == 1 &&
 548             !(evsel->core.attr.config & 1)) {
 549                 pr_warning("pt=0 doesn't make sense, forcing pt=1\n");
 550                 evsel->core.attr.config |= 1;
 551         }
 552
 553         err = intel_pt_val_config_term(intel_pt_pmu, "caps/cycle_thresholds",
 554                                        "cyc_thresh", "caps/psb_cyc",
 555                                        evsel->core.attr.config);
 556         if (err)
 557                 return err;
 558
 559         err = intel_pt_val_config_term(intel_pt_pmu, "caps/mtc_periods",
 560                                        "mtc_period", "caps/mtc",
 561                                        evsel->core.attr.config);
 562         if (err)
 563                 return err;
 564
 565         return intel_pt_val_config_term(intel_pt_pmu, "caps/psb_periods",
 566                                         "psb_period", "caps/psb_cyc",
 567                                         evsel->core.attr.config);
 568 }
 569
 570 static void intel_pt_config_sample_mode(struct perf_pmu *intel_pt_pmu,
 571                                         struct evsel *evsel)
 572 {
 573         u64 user_bits = 0, bits;
 574         struct evsel_config_term *term = evsel__get_config_term(evsel, CFG_CHG);
 575
 576         if (term)
 577                 user_bits = term->val.cfg_chg;
 578
 579         bits = perf_pmu__format_bits(&intel_pt_pmu->format, "psb_period");
 580
 581         /* Did user change psb_period */
 582         if (bits & user_bits)
 583                 return;
 584
 585         /* Set psb_period to 0 */
 586         evsel->core.attr.config &= ~bits;
 587 }
 588
 589 static void intel_pt_min_max_sample_sz(struct evlist *evlist,
 590                                        size_t *min_sz, size_t *max_sz)
 591 {
 592         struct evsel *evsel;
 593
 594         evlist__for_each_entry(evlist, evsel) {
 595                 size_t sz = evsel->core.attr.aux_sample_size;
 596
 597                 if (!sz)
 598                         continue;
 599                 if (min_sz && (sz < *min_sz || !*min_sz))
 600                         *min_sz = sz;
 601                 if (max_sz && sz > *max_sz)
 602                         *max_sz = sz;
 603         }
 604 }
 605
 606 /*
 607  * Currently, there is not enough information to disambiguate different PEBS
 608  * events, so only allow one.
 609  */
 610 static bool intel_pt_too_many_aux_output(struct evlist *evlist)
 611 {
 612         struct evsel *evsel;
 613         int aux_output_cnt = 0;
 614
 615         evlist__for_each_entry(evlist, evsel)
 616                 aux_output_cnt += !!evsel->core.attr.aux_output;
 617
 618         if (aux_output_cnt > 1) {
 619                 pr_err(INTEL_PT_PMU_NAME " supports at most one event with aux-output\n");
 620                 return true;
 621         }
 622
 623         return false;
 624 }
 625
 626 static int intel_pt_recording_options(struct auxtrace_record *itr,
 627                                       struct evlist *evlist,
 628                                       struct record_opts *opts)
 629 {
 630         struct intel_pt_recording *ptr =
 631                         container_of(itr, struct intel_pt_recording, itr);
 632         struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
 633         bool have_timing_info, need_immediate = false;
 634         struct evsel *evsel, *intel_pt_evsel = NULL;
 635         const struct perf_cpu_map *cpus = evlist->core.cpus;
 636         bool privileged = perf_event_paranoid_check(-1);
 637         u64 tsc_bit;
 638         int err;
 639
 640         ptr->evlist = evlist;
 641         ptr->snapshot_mode = opts->auxtrace_snapshot_mode;
 642
 643         evlist__for_each_entry(evlist, evsel) {
 644                 if (evsel->core.attr.type == intel_pt_pmu->type) {
 645                         if (intel_pt_evsel) {
 646                                 pr_err("There may be only one " INTEL_PT_PMU_NAME " event\n");
 647                                 return -EINVAL;
 648                         }
 649                         evsel->core.attr.freq = 0;
 650                         evsel->core.attr.sample_period = 1;
 651                         evsel->no_aux_samples = true;
 652                         intel_pt_evsel = evsel;
 653                         opts->full_auxtrace = true;
 654                 }
 655         }
 656
 657         if (opts->auxtrace_snapshot_mode && !opts->full_auxtrace) {
 658                 pr_err("Snapshot mode (-S option) requires " INTEL_PT_PMU_NAME " PMU event (-e " INTEL_PT_PMU_NAME ")\n");
 659                 return -EINVAL;
 660         }
 661
 662         if (opts->auxtrace_snapshot_mode && opts->auxtrace_sample_mode) {
 663                 pr_err("Snapshot mode (" INTEL_PT_PMU_NAME " PMU) and sample trace cannot be used together\n");
 664                 return -EINVAL;
 665         }
 666
 667         if (opts->use_clockid) {
 668                 pr_err("Cannot use clockid (-k option) with " INTEL_PT_PMU_NAME "\n");
 669                 return -EINVAL;
 670         }
 671
 672         if (intel_pt_too_many_aux_output(evlist))
 673                 return -EINVAL;
 674
 675         if (!opts->full_auxtrace)
 676                 return 0;
 677
 678         if (opts->auxtrace_sample_mode)
 679                 intel_pt_config_sample_mode(intel_pt_pmu, intel_pt_evsel);
 680
 681         err = intel_pt_validate_config(intel_pt_pmu, intel_pt_evsel);
 682         if (err)
 683                 return err;
 684
 685         /* Set default sizes for snapshot mode */
 686         if (opts->auxtrace_snapshot_mode) {
 687                 size_t psb_period = intel_pt_psb_period(intel_pt_pmu, evlist);
 688
 689                 if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) {
 690                         if (privileged) {
 691                                 opts->auxtrace_mmap_pages = MiB(4) / page_size;
 692                         } else {
 693                                 opts->auxtrace_mmap_pages = KiB(128) / page_size;
 694                                 if (opts->mmap_pages == UINT_MAX)
 695                                         opts->mmap_pages = KiB(256) / page_size;
 696                         }
 697                 } else if (!opts->auxtrace_mmap_pages && !privileged &&
 698                            opts->mmap_pages == UINT_MAX) {
 699                         opts->mmap_pages = KiB(256) / page_size;
 700                 }
 701                 if (!opts->auxtrace_snapshot_size)
 702                         opts->auxtrace_snapshot_size =
 703                                 opts->auxtrace_mmap_pages * (size_t)page_size;
 704                 if (!opts->auxtrace_mmap_pages) {
 705                         size_t sz = opts->auxtrace_snapshot_size;
 706
 707                         sz = round_up(sz, page_size) / page_size;
 708                         opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
 709                 }
 710                 if (opts->auxtrace_snapshot_size >
 711                                 opts->auxtrace_mmap_pages * (size_t)page_size) {
 712                         pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
 713                                opts->auxtrace_snapshot_size,
 714                                opts->auxtrace_mmap_pages * (size_t)page_size);
 715                         return -EINVAL;
 716                 }
 717                 if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) {
 718                         pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
 719                         return -EINVAL;
 720                 }
 721                 pr_debug2("Intel PT snapshot size: %zu\n",
 722                           opts->auxtrace_snapshot_size);
 723                 if (psb_period &&
 724                     opts->auxtrace_snapshot_size <= psb_period +
 725                                                   INTEL_PT_PSB_PERIOD_NEAR)
 726                         ui__warning("Intel PT snapshot size (%zu) may be too small for PSB period (%zu)\n",
 727                                     opts->auxtrace_snapshot_size, psb_period);
 728         }
 729
 730         /* Set default sizes for sample mode */
 731         if (opts->auxtrace_sample_mode) {
 732                 size_t psb_period = intel_pt_psb_period(intel_pt_pmu, evlist);
 733                 size_t min_sz = 0, max_sz = 0;
 734
 735                 intel_pt_min_max_sample_sz(evlist, &min_sz, &max_sz);
 736                 if (!opts->auxtrace_mmap_pages && !privileged &&
 737                     opts->mmap_pages == UINT_MAX)
 738                         opts->mmap_pages = KiB(256) / page_size;
 739                 if (!opts->auxtrace_mmap_pages) {
 740                         size_t sz = round_up(max_sz, page_size) / page_size;
 741
 742                         opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
 743                 }
 744                 if (max_sz > opts->auxtrace_mmap_pages * (size_t)page_size) {
 745                         pr_err("Sample size %zu must not be greater than AUX area tracing mmap size %zu\n",
 746                                max_sz,
 747                                opts->auxtrace_mmap_pages * (size_t)page_size);
 748                         return -EINVAL;
 749                 }
 750                 pr_debug2("Intel PT min. sample size: %zu max. sample size: %zu\n",
 751                           min_sz, max_sz);
 752                 if (psb_period &&
 753                     min_sz <= psb_period + INTEL_PT_PSB_PERIOD_NEAR)
 754                         ui__warning("Intel PT sample size (%zu) may be too small for PSB period (%zu)\n",
 755                                     min_sz, psb_period);
 756         }
 757
 758         /* Set default sizes for full trace mode */
 759         if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
 760                 if (privileged) {
 761                         opts->auxtrace_mmap_pages = MiB(4) / page_size;
 762                 } else {
 763                         opts->auxtrace_mmap_pages = KiB(128) / page_size;
 764                         if (opts->mmap_pages == UINT_MAX)
 765                                 opts->mmap_pages = KiB(256) / page_size;
 766                 }
 767         }
 768
 769         /* Validate auxtrace_mmap_pages */
 770         if (opts->auxtrace_mmap_pages) {
 771                 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
 772                 size_t min_sz;
 773
 774                 if (opts->auxtrace_snapshot_mode || opts->auxtrace_sample_mode)
 775                         min_sz = KiB(4);
 776                 else
 777                         min_sz = KiB(8);
 778
 779                 if (sz < min_sz || !is_power_of_2(sz)) {
 780                         pr_err("Invalid mmap size for Intel Processor Trace: must be at least %zuKiB and a power of 2\n",
 781                                min_sz / 1024);
 782                         return -EINVAL;
 783                 }
 784         }
 785
 786         if (!opts->auxtrace_snapshot_mode && !opts->auxtrace_sample_mode) {
 787                 u32 aux_watermark = opts->auxtrace_mmap_pages * page_size / 4;
 788
 789                 intel_pt_evsel->core.attr.aux_watermark = aux_watermark;
 790         }
 791
 792         intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format,
 793                              "tsc", &tsc_bit);
 794
 795         if (opts->full_auxtrace && (intel_pt_evsel->core.attr.config & tsc_bit))
 796                 have_timing_info = true;
 797         else
 798                 have_timing_info = false;
 799
 800         /*
 801          * Per-cpu recording needs sched_switch events to distinguish different
 802          * threads.
 803          */
 804         if (have_timing_info && !perf_cpu_map__empty(cpus) &&
 805             !record_opts__no_switch_events(opts)) {
 806                 if (perf_can_record_switch_events()) {
 807                         bool cpu_wide = !target__none(&opts->target) &&
 808                                         !target__has_task(&opts->target);
 809
 810                         if (!cpu_wide && perf_can_record_cpu_wide()) {
 811                                 struct evsel *switch_evsel;
 812
 813                                 err = parse_events(evlist, "dummy:u", NULL);
 814                                 if (err)
 815                                         return err;
 816
 817                                 switch_evsel = evlist__last(evlist);
 818
 819                                 switch_evsel->core.attr.freq = 0;
 820                                 switch_evsel->core.attr.sample_period = 1;
 821                                 switch_evsel->core.attr.context_switch = 1;
 822
 823                                 switch_evsel->core.system_wide = true;
 824                                 switch_evsel->no_aux_samples = true;
 825                                 switch_evsel->immediate = true;
 826
 827                                 evsel__set_sample_bit(switch_evsel, TID);
 828                                 evsel__set_sample_bit(switch_evsel, TIME);
 829                                 evsel__set_sample_bit(switch_evsel, CPU);
 830                                 evsel__reset_sample_bit(switch_evsel, BRANCH_STACK);
 831
 832                                 opts->record_switch_events = false;
 833                                 ptr->have_sched_switch = 3;
 834                         } else {
 835                                 opts->record_switch_events = true;
 836                                 need_immediate = true;
 837                                 if (cpu_wide)
 838                                         ptr->have_sched_switch = 3;
 839                                 else
 840                                         ptr->have_sched_switch = 2;
 841                         }
 842                 } else {
 843                         err = intel_pt_track_switches(evlist);
 844                         if (err == -EPERM)
 845                                 pr_debug2("Unable to select sched:sched_switch\n");
 846                         else if (err)
 847                                 return err;
 848                         else
 849                                 ptr->have_sched_switch = 1;
 850                 }
 851         }
 852
 853         if (have_timing_info && !intel_pt_evsel->core.attr.exclude_kernel &&
 854             perf_can_record_text_poke_events() && perf_can_record_cpu_wide())
 855                 opts->text_poke = true;
 856
 857         if (intel_pt_evsel) {
 858                 /*
 859                  * To obtain the auxtrace buffer file descriptor, the auxtrace
 860                  * event must come first.
 861                  */
 862                 evlist__to_front(evlist, intel_pt_evsel);
 863                 /*
 864                  * In the case of per-cpu mmaps, we need the CPU on the
 865                  * AUX event.
 866                  */
 867                 if (!perf_cpu_map__empty(cpus))
 868                         evsel__set_sample_bit(intel_pt_evsel, CPU);
 869         }
 870
 871         /* Add dummy event to keep tracking */
 872         if (opts->full_auxtrace) {
 873                 struct evsel *tracking_evsel;
 874
 875                 err = parse_events(evlist, "dummy:u", NULL);
 876                 if (err)
 877                         return err;
 878
 879                 tracking_evsel = evlist__last(evlist);
 880
 881                 evlist__set_tracking_event(evlist, tracking_evsel);
 882
 883                 tracking_evsel->core.attr.freq = 0;
 884                 tracking_evsel->core.attr.sample_period = 1;
 885
 886                 tracking_evsel->no_aux_samples = true;
 887                 if (need_immediate)
 888                         tracking_evsel->immediate = true;
 889
 890                 /* In per-cpu case, always need the time of mmap events etc */
 891                 if (!perf_cpu_map__empty(cpus)) {
 892                         evsel__set_sample_bit(tracking_evsel, TIME);
 893                         /* And the CPU for switch events */
 894                         evsel__set_sample_bit(tracking_evsel, CPU);
 895                 }
 896                 evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK);
 897         }
 898
 899         /*
 900          * Warn the user when we do not have enough information to decode i.e.
 901          * per-cpu with no sched_switch (except workload-only).
 902          */
 903         if (!ptr->have_sched_switch && !perf_cpu_map__empty(cpus) &&
 904             !target__none(&opts->target) &&
 905             !intel_pt_evsel->core.attr.exclude_user)
 906                 ui__warning("Intel Processor Trace decoding will not be possible except for kernel tracing!\n");
 907
 908         return 0;
 909 }
 910
 911 static int intel_pt_snapshot_start(struct auxtrace_record *itr)
 912 {
 913         struct intel_pt_recording *ptr =
 914                         container_of(itr, struct intel_pt_recording, itr);
 915         struct evsel *evsel;
 916
 917         evlist__for_each_entry(ptr->evlist, evsel) {
 918                 if (evsel->core.attr.type == ptr->intel_pt_pmu->type)
 919                         return evsel__disable(evsel);
 920         }
 921         return -EINVAL;
 922 }
 923
 924 static int intel_pt_snapshot_finish(struct auxtrace_record *itr)
 925 {
 926         struct intel_pt_recording *ptr =
 927                         container_of(itr, struct intel_pt_recording, itr);
 928         struct evsel *evsel;
 929
 930         evlist__for_each_entry(ptr->evlist, evsel) {
 931                 if (evsel->core.attr.type == ptr->intel_pt_pmu->type)
 932                         return evsel__enable(evsel);
 933         }
 934         return -EINVAL;
 935 }
 936
 937 static int intel_pt_alloc_snapshot_refs(struct intel_pt_recording *ptr, int idx)
 938 {
 939         const size_t sz = sizeof(struct intel_pt_snapshot_ref);
 940         int cnt = ptr->snapshot_ref_cnt, new_cnt = cnt * 2;
 941         struct intel_pt_snapshot_ref *refs;
 942
 943         if (!new_cnt)
 944                 new_cnt = 16;
 945
 946         while (new_cnt <= idx)
 947                 new_cnt *= 2;
 948
 949         refs = calloc(new_cnt, sz);
 950         if (!refs)
 951                 return -ENOMEM;
 952
 953         memcpy(refs, ptr->snapshot_refs, cnt * sz);
 954
 955         ptr->snapshot_refs = refs;
 956         ptr->snapshot_ref_cnt = new_cnt;
 957
 958         return 0;
 959 }
 960
 961 static void intel_pt_free_snapshot_refs(struct intel_pt_recording *ptr)
 962 {
 963         int i;
 964
 965         for (i = 0; i < ptr->snapshot_ref_cnt; i++)
 966                 zfree(&ptr->snapshot_refs[i].ref_buf);
 967         zfree(&ptr->snapshot_refs);
 968 }
 969
 970 static void intel_pt_recording_free(struct auxtrace_record *itr)
 971 {
 972         struct intel_pt_recording *ptr =
 973                         container_of(itr, struct intel_pt_recording, itr);
 974
 975         intel_pt_free_snapshot_refs(ptr);
 976         free(ptr);
 977 }
 978
 979 static int intel_pt_alloc_snapshot_ref(struct intel_pt_recording *ptr, int idx,
 980                                        size_t snapshot_buf_size)
 981 {
 982         size_t ref_buf_size = ptr->snapshot_ref_buf_size;
 983         void *ref_buf;
 984
 985         ref_buf = zalloc(ref_buf_size);
 986         if (!ref_buf)
 987                 return -ENOMEM;
 988
 989         ptr->snapshot_refs[idx].ref_buf = ref_buf;
 990         ptr->snapshot_refs[idx].ref_offset = snapshot_buf_size - ref_buf_size;
 991
 992         return 0;
 993 }
 994
 995 static size_t intel_pt_snapshot_ref_buf_size(struct intel_pt_recording *ptr,
 996                                              size_t snapshot_buf_size)
 997 {
 998         const size_t max_size = 256 * 1024;
 999         size_t buf_size = 0, psb_period;
1000
1001         if (ptr->snapshot_size <= 64 * 1024)
1002                 return 0;
1003
1004         psb_period = intel_pt_psb_period(ptr->intel_pt_pmu, ptr->evlist);
1005         if (psb_period)
1006                 buf_size = psb_period * 2;
1007
1008         if (!buf_size || buf_size > max_size)
1009                 buf_size = max_size;
1010
1011         if (buf_size >= snapshot_buf_size)
1012                 return 0;
1013
1014         if (buf_size >= ptr->snapshot_size / 2)
1015                 return 0;
1016
1017         return buf_size;
1018 }
1019
1020 static int intel_pt_snapshot_init(struct intel_pt_recording *ptr,
1021                                   size_t snapshot_buf_size)
1022 {
1023         if (ptr->snapshot_init_done)
1024                 return 0;
1025
1026         ptr->snapshot_init_done = true;
1027
1028         ptr->snapshot_ref_buf_size = intel_pt_snapshot_ref_buf_size(ptr,
1029                                                         snapshot_buf_size);
1030
1031         return 0;
1032 }
1033
1034 /**
1035  * intel_pt_compare_buffers - compare bytes in a buffer to a circular buffer.
1036  * @buf1: first buffer
1037  * @compare_size: number of bytes to compare
1038  * @buf2: second buffer (a circular buffer)
1039  * @offs2: offset in second buffer
1040  * @buf2_size: size of second buffer
1041  *
1042  * The comparison allows for the possibility that the bytes to compare in the
1043  * circular buffer are not contiguous.  It is assumed that @compare_size <=
1044  * @buf2_size.  This function returns %false if the bytes are identical, %true
1045  * otherwise.
1046  */
1047 static bool intel_pt_compare_buffers(void *buf1, size_t compare_size,
1048                                      void *buf2, size_t offs2, size_t buf2_size)
1049 {
1050         size_t end2 = offs2 + compare_size, part_size;
1051
1052         if (end2 <= buf2_size)
1053                 return memcmp(buf1, buf2 + offs2, compare_size);
1054
1055         part_size = end2 - buf2_size;
1056         if (memcmp(buf1, buf2 + offs2, part_size))
1057                 return true;
1058
1059         compare_size -= part_size;
1060
1061         return memcmp(buf1 + part_size, buf2, compare_size);
1062 }
1063
1064 static bool intel_pt_compare_ref(void *ref_buf, size_t ref_offset,
1065                                  size_t ref_size, size_t buf_size,
1066                                  void *data, size_t head)
1067 {
1068         size_t ref_end = ref_offset + ref_size;
1069
1070         if (ref_end > buf_size) {
1071                 if (head > ref_offset || head < ref_end - buf_size)
1072                         return true;
1073         } else if (head > ref_offset && head < ref_end) {
1074                 return true;
1075         }
1076
1077         return intel_pt_compare_buffers(ref_buf, ref_size, data, ref_offset,
1078                                         buf_size);
1079 }
1080
1081 static void intel_pt_copy_ref(void *ref_buf, size_t ref_size, size_t buf_size,
1082                               void *data, size_t head)
1083 {
1084         if (head >= ref_size) {
1085                 memcpy(ref_buf, data + head - ref_size, ref_size);
1086         } else {
1087                 memcpy(ref_buf, data, head);
1088                 ref_size -= head;
1089                 memcpy(ref_buf + head, data + buf_size - ref_size, ref_size);
1090         }
1091 }
1092
1093 static bool intel_pt_wrapped(struct intel_pt_recording *ptr, int idx,
1094                              struct auxtrace_mmap *mm, unsigned char *data,
1095                              u64 head)
1096 {
1097         struct intel_pt_snapshot_ref *ref = &ptr->snapshot_refs[idx];
1098         bool wrapped;
1099
1100         wrapped = intel_pt_compare_ref(ref->ref_buf, ref->ref_offset,
1101                                        ptr->snapshot_ref_buf_size, mm->len,
1102                                        data, head);
1103
1104         intel_pt_copy_ref(ref->ref_buf, ptr->snapshot_ref_buf_size, mm->len,
1105                           data, head);
1106
1107         return wrapped;
1108 }
1109
1110 static bool intel_pt_first_wrap(u64 *data, size_t buf_size)
1111 {
1112         int i, a, b;
1113
1114         b = buf_size >> 3;
1115         a = b - 512;
1116         if (a < 0)
1117                 a = 0;
1118
1119         for (i = a; i < b; i++) {
1120                 if (data[i])
1121                         return true;
1122         }
1123
1124         return false;
1125 }
1126
1127 static int intel_pt_find_snapshot(struct auxtrace_record *itr, int idx,
1128                                   struct auxtrace_mmap *mm, unsigned char *data,
1129                                   u64 *head, u64 *old)
1130 {
1131         struct intel_pt_recording *ptr =
1132                         container_of(itr, struct intel_pt_recording, itr);
1133         bool wrapped;
1134         int err;
1135
1136         pr_debug3("%s: mmap index %d old head %zu new head %zu\n",
1137                   __func__, idx, (size_t)*old, (size_t)*head);
1138
1139         err = intel_pt_snapshot_init(ptr, mm->len);
1140         if (err)
1141                 goto out_err;
1142
1143         if (idx >= ptr->snapshot_ref_cnt) {
1144                 err = intel_pt_alloc_snapshot_refs(ptr, idx);
1145                 if (err)
1146                         goto out_err;
1147         }
1148
1149         if (ptr->snapshot_ref_buf_size) {
1150                 if (!ptr->snapshot_refs[idx].ref_buf) {
1151                         err = intel_pt_alloc_snapshot_ref(ptr, idx, mm->len);
1152                         if (err)
1153                                 goto out_err;
1154                 }
1155                 wrapped = intel_pt_wrapped(ptr, idx, mm, data, *head);
1156         } else {
1157                 wrapped = ptr->snapshot_refs[idx].wrapped;
1158                 if (!wrapped && intel_pt_first_wrap((u64 *)data, mm->len)) {
1159                         ptr->snapshot_refs[idx].wrapped = true;
1160                         wrapped = true;
1161                 }
1162         }
1163
1164         /*
1165          * In full trace mode 'head' continually increases.  However in snapshot
1166          * mode 'head' is an offset within the buffer.  Here 'old' and 'head'
1167          * are adjusted to match the full trace case which expects that 'old' is
1168          * always less than 'head'.
1169          */
1170         if (wrapped) {
1171                 *old = *head;
1172                 *head += mm->len;
1173         } else {
1174                 if (mm->mask)
1175                         *old &= mm->mask;
1176                 else
1177                         *old %= mm->len;
1178                 if (*old > *head)
1179                         *head += mm->len;
1180         }
1181
1182         pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n",
1183                   __func__, wrapped ? "" : "not ", (size_t)*old, (size_t)*head);
1184
1185         return 0;
1186
1187 out_err:
1188         pr_err("%s: failed, error %d\n", __func__, err);
1189         return err;
1190 }
1191
1192 static u64 intel_pt_reference(struct auxtrace_record *itr __maybe_unused)
1193 {
1194         return rdtsc();
1195 }
1196
1197 struct auxtrace_record *intel_pt_recording_init(int *err)
1198 {
1199         struct perf_pmu *intel_pt_pmu = perf_pmu__find(INTEL_PT_PMU_NAME);
1200         struct intel_pt_recording *ptr;
1201
1202         if (!intel_pt_pmu)
1203                 return NULL;
1204
1205         if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) {
1206                 *err = -errno;
1207                 return NULL;
1208         }
1209
1210         ptr = zalloc(sizeof(struct intel_pt_recording));
1211         if (!ptr) {
1212                 *err = -ENOMEM;
1213                 return NULL;
1214         }
1215
1216         ptr->intel_pt_pmu = intel_pt_pmu;
1217         ptr->itr.pmu = intel_pt_pmu;
1218         ptr->itr.recording_options = intel_pt_recording_options;
1219         ptr->itr.info_priv_size = intel_pt_info_priv_size;
1220         ptr->itr.info_fill = intel_pt_info_fill;
1221         ptr->itr.free = intel_pt_recording_free;
1222         ptr->itr.snapshot_start = intel_pt_snapshot_start;
1223         ptr->itr.snapshot_finish = intel_pt_snapshot_finish;
1224         ptr->itr.find_snapshot = intel_pt_find_snapshot;
1225         ptr->itr.parse_snapshot_options = intel_pt_parse_snapshot_options;
1226         ptr->itr.reference = intel_pt_reference;
1227         ptr->itr.read_finish = auxtrace_record__read_finish;
1228         /*
1229          * Decoding starts at a PSB packet. Minimum PSB period is 2K so 4K
1230          * should give at least 1 PSB per sample.
1231          */
1232         ptr->itr.default_aux_sample_size = 4096;
1233         return &ptr->itr;
1234 }