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