linux/tools/perf/arch/x86/util/intel-pt.c
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   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
  42struct intel_pt_snapshot_ref {
  43        void *ref_buf;
  44        size_t ref_offset;
  45        bool wrapped;
  46};
  47
  48struct 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
  62static 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;
  88out_free:
  89        parse_events_terms__delete(terms);
  90        return err;
  91}
  92
  93static 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
 101static 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
 120static 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
 142static 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);
 167out:
 168        pr_debug2("%s psb_period %zu\n", intel_pt_pmu->name, psb_period);
 169        return psb_period;
 170}
 171
 172static 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
 188static 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
 241static 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
 264struct perf_event_attr *
 265intel_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
 280static 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
 293static 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
 300static size_t
 301intel_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
 313static 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
 322static 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
 413static 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
 441static 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
 487static 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;
 520out_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
 527static 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
 563static 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
 582static 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 */
 603static 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
 619static 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        if (!opts->auxtrace_snapshot_mode && !opts->auxtrace_sample_mode) {
 780                u32 aux_watermark = opts->auxtrace_mmap_pages * page_size / 4;
 781
 782                intel_pt_evsel->core.attr.aux_watermark = aux_watermark;
 783        }
 784
 785        intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format,
 786                             "tsc", &tsc_bit);
 787
 788        if (opts->full_auxtrace && (intel_pt_evsel->core.attr.config & tsc_bit))
 789                have_timing_info = true;
 790        else
 791                have_timing_info = false;
 792
 793        /*
 794         * Per-cpu recording needs sched_switch events to distinguish different
 795         * threads.
 796         */
 797        if (have_timing_info && !perf_cpu_map__empty(cpus) &&
 798            !record_opts__no_switch_events(opts)) {
 799                if (perf_can_record_switch_events()) {
 800                        bool cpu_wide = !target__none(&opts->target) &&
 801                                        !target__has_task(&opts->target);
 802
 803                        if (!cpu_wide && perf_can_record_cpu_wide()) {
 804                                struct evsel *switch_evsel;
 805
 806                                err = parse_events(evlist, "dummy:u", NULL);
 807                                if (err)
 808                                        return err;
 809
 810                                switch_evsel = evlist__last(evlist);
 811
 812                                switch_evsel->core.attr.freq = 0;
 813                                switch_evsel->core.attr.sample_period = 1;
 814                                switch_evsel->core.attr.context_switch = 1;
 815
 816                                switch_evsel->core.system_wide = true;
 817                                switch_evsel->no_aux_samples = true;
 818                                switch_evsel->immediate = true;
 819
 820                                evsel__set_sample_bit(switch_evsel, TID);
 821                                evsel__set_sample_bit(switch_evsel, TIME);
 822                                evsel__set_sample_bit(switch_evsel, CPU);
 823                                evsel__reset_sample_bit(switch_evsel, BRANCH_STACK);
 824
 825                                opts->record_switch_events = false;
 826                                ptr->have_sched_switch = 3;
 827                        } else {
 828                                opts->record_switch_events = true;
 829                                need_immediate = true;
 830                                if (cpu_wide)
 831                                        ptr->have_sched_switch = 3;
 832                                else
 833                                        ptr->have_sched_switch = 2;
 834                        }
 835                } else {
 836                        err = intel_pt_track_switches(evlist);
 837                        if (err == -EPERM)
 838                                pr_debug2("Unable to select sched:sched_switch\n");
 839                        else if (err)
 840                                return err;
 841                        else
 842                                ptr->have_sched_switch = 1;
 843                }
 844        }
 845
 846        if (have_timing_info && !intel_pt_evsel->core.attr.exclude_kernel &&
 847            perf_can_record_text_poke_events() && perf_can_record_cpu_wide())
 848                opts->text_poke = true;
 849
 850        if (intel_pt_evsel) {
 851                /*
 852                 * To obtain the auxtrace buffer file descriptor, the auxtrace
 853                 * event must come first.
 854                 */
 855                evlist__to_front(evlist, intel_pt_evsel);
 856                /*
 857                 * In the case of per-cpu mmaps, we need the CPU on the
 858                 * AUX event.
 859                 */
 860                if (!perf_cpu_map__empty(cpus))
 861                        evsel__set_sample_bit(intel_pt_evsel, CPU);
 862        }
 863
 864        /* Add dummy event to keep tracking */
 865        if (opts->full_auxtrace) {
 866                struct evsel *tracking_evsel;
 867
 868                err = parse_events(evlist, "dummy:u", NULL);
 869                if (err)
 870                        return err;
 871
 872                tracking_evsel = evlist__last(evlist);
 873
 874                evlist__set_tracking_event(evlist, tracking_evsel);
 875
 876                tracking_evsel->core.attr.freq = 0;
 877                tracking_evsel->core.attr.sample_period = 1;
 878
 879                tracking_evsel->no_aux_samples = true;
 880                if (need_immediate)
 881                        tracking_evsel->immediate = true;
 882
 883                /* In per-cpu case, always need the time of mmap events etc */
 884                if (!perf_cpu_map__empty(cpus)) {
 885                        evsel__set_sample_bit(tracking_evsel, TIME);
 886                        /* And the CPU for switch events */
 887                        evsel__set_sample_bit(tracking_evsel, CPU);
 888                }
 889                evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK);
 890        }
 891
 892        /*
 893         * Warn the user when we do not have enough information to decode i.e.
 894         * per-cpu with no sched_switch (except workload-only).
 895         */
 896        if (!ptr->have_sched_switch && !perf_cpu_map__empty(cpus) &&
 897            !target__none(&opts->target) &&
 898            !intel_pt_evsel->core.attr.exclude_user)
 899                ui__warning("Intel Processor Trace decoding will not be possible except for kernel tracing!\n");
 900
 901        return 0;
 902}
 903
 904static int intel_pt_snapshot_start(struct auxtrace_record *itr)
 905{
 906        struct intel_pt_recording *ptr =
 907                        container_of(itr, struct intel_pt_recording, itr);
 908        struct evsel *evsel;
 909
 910        evlist__for_each_entry(ptr->evlist, evsel) {
 911                if (evsel->core.attr.type == ptr->intel_pt_pmu->type)
 912                        return evsel__disable(evsel);
 913        }
 914        return -EINVAL;
 915}
 916
 917static int intel_pt_snapshot_finish(struct auxtrace_record *itr)
 918{
 919        struct intel_pt_recording *ptr =
 920                        container_of(itr, struct intel_pt_recording, itr);
 921        struct evsel *evsel;
 922
 923        evlist__for_each_entry(ptr->evlist, evsel) {
 924                if (evsel->core.attr.type == ptr->intel_pt_pmu->type)
 925                        return evsel__enable(evsel);
 926        }
 927        return -EINVAL;
 928}
 929
 930static int intel_pt_alloc_snapshot_refs(struct intel_pt_recording *ptr, int idx)
 931{
 932        const size_t sz = sizeof(struct intel_pt_snapshot_ref);
 933        int cnt = ptr->snapshot_ref_cnt, new_cnt = cnt * 2;
 934        struct intel_pt_snapshot_ref *refs;
 935
 936        if (!new_cnt)
 937                new_cnt = 16;
 938
 939        while (new_cnt <= idx)
 940                new_cnt *= 2;
 941
 942        refs = calloc(new_cnt, sz);
 943        if (!refs)
 944                return -ENOMEM;
 945
 946        memcpy(refs, ptr->snapshot_refs, cnt * sz);
 947
 948        ptr->snapshot_refs = refs;
 949        ptr->snapshot_ref_cnt = new_cnt;
 950
 951        return 0;
 952}
 953
 954static void intel_pt_free_snapshot_refs(struct intel_pt_recording *ptr)
 955{
 956        int i;
 957
 958        for (i = 0; i < ptr->snapshot_ref_cnt; i++)
 959                zfree(&ptr->snapshot_refs[i].ref_buf);
 960        zfree(&ptr->snapshot_refs);
 961}
 962
 963static void intel_pt_recording_free(struct auxtrace_record *itr)
 964{
 965        struct intel_pt_recording *ptr =
 966                        container_of(itr, struct intel_pt_recording, itr);
 967
 968        intel_pt_free_snapshot_refs(ptr);
 969        free(ptr);
 970}
 971
 972static int intel_pt_alloc_snapshot_ref(struct intel_pt_recording *ptr, int idx,
 973                                       size_t snapshot_buf_size)
 974{
 975        size_t ref_buf_size = ptr->snapshot_ref_buf_size;
 976        void *ref_buf;
 977
 978        ref_buf = zalloc(ref_buf_size);
 979        if (!ref_buf)
 980                return -ENOMEM;
 981
 982        ptr->snapshot_refs[idx].ref_buf = ref_buf;
 983        ptr->snapshot_refs[idx].ref_offset = snapshot_buf_size - ref_buf_size;
 984
 985        return 0;
 986}
 987
 988static size_t intel_pt_snapshot_ref_buf_size(struct intel_pt_recording *ptr,
 989                                             size_t snapshot_buf_size)
 990{
 991        const size_t max_size = 256 * 1024;
 992        size_t buf_size = 0, psb_period;
 993
 994        if (ptr->snapshot_size <= 64 * 1024)
 995                return 0;
 996
 997        psb_period = intel_pt_psb_period(ptr->intel_pt_pmu, ptr->evlist);
 998        if (psb_period)
 999                buf_size = psb_period * 2;
1000
1001        if (!buf_size || buf_size > max_size)
1002                buf_size = max_size;
1003
1004        if (buf_size >= snapshot_buf_size)
1005                return 0;
1006
1007        if (buf_size >= ptr->snapshot_size / 2)
1008                return 0;
1009
1010        return buf_size;
1011}
1012
1013static int intel_pt_snapshot_init(struct intel_pt_recording *ptr,
1014                                  size_t snapshot_buf_size)
1015{
1016        if (ptr->snapshot_init_done)
1017                return 0;
1018
1019        ptr->snapshot_init_done = true;
1020
1021        ptr->snapshot_ref_buf_size = intel_pt_snapshot_ref_buf_size(ptr,
1022                                                        snapshot_buf_size);
1023
1024        return 0;
1025}
1026
1027/**
1028 * intel_pt_compare_buffers - compare bytes in a buffer to a circular buffer.
1029 * @buf1: first buffer
1030 * @compare_size: number of bytes to compare
1031 * @buf2: second buffer (a circular buffer)
1032 * @offs2: offset in second buffer
1033 * @buf2_size: size of second buffer
1034 *
1035 * The comparison allows for the possibility that the bytes to compare in the
1036 * circular buffer are not contiguous.  It is assumed that @compare_size <=
1037 * @buf2_size.  This function returns %false if the bytes are identical, %true
1038 * otherwise.
1039 */
1040static bool intel_pt_compare_buffers(void *buf1, size_t compare_size,
1041                                     void *buf2, size_t offs2, size_t buf2_size)
1042{
1043        size_t end2 = offs2 + compare_size, part_size;
1044
1045        if (end2 <= buf2_size)
1046                return memcmp(buf1, buf2 + offs2, compare_size);
1047
1048        part_size = end2 - buf2_size;
1049        if (memcmp(buf1, buf2 + offs2, part_size))
1050                return true;
1051
1052        compare_size -= part_size;
1053
1054        return memcmp(buf1 + part_size, buf2, compare_size);
1055}
1056
1057static bool intel_pt_compare_ref(void *ref_buf, size_t ref_offset,
1058                                 size_t ref_size, size_t buf_size,
1059                                 void *data, size_t head)
1060{
1061        size_t ref_end = ref_offset + ref_size;
1062
1063        if (ref_end > buf_size) {
1064                if (head > ref_offset || head < ref_end - buf_size)
1065                        return true;
1066        } else if (head > ref_offset && head < ref_end) {
1067                return true;
1068        }
1069
1070        return intel_pt_compare_buffers(ref_buf, ref_size, data, ref_offset,
1071                                        buf_size);
1072}
1073
1074static void intel_pt_copy_ref(void *ref_buf, size_t ref_size, size_t buf_size,
1075                              void *data, size_t head)
1076{
1077        if (head >= ref_size) {
1078                memcpy(ref_buf, data + head - ref_size, ref_size);
1079        } else {
1080                memcpy(ref_buf, data, head);
1081                ref_size -= head;
1082                memcpy(ref_buf + head, data + buf_size - ref_size, ref_size);
1083        }
1084}
1085
1086static bool intel_pt_wrapped(struct intel_pt_recording *ptr, int idx,
1087                             struct auxtrace_mmap *mm, unsigned char *data,
1088                             u64 head)
1089{
1090        struct intel_pt_snapshot_ref *ref = &ptr->snapshot_refs[idx];
1091        bool wrapped;
1092
1093        wrapped = intel_pt_compare_ref(ref->ref_buf, ref->ref_offset,
1094                                       ptr->snapshot_ref_buf_size, mm->len,
1095                                       data, head);
1096
1097        intel_pt_copy_ref(ref->ref_buf, ptr->snapshot_ref_buf_size, mm->len,
1098                          data, head);
1099
1100        return wrapped;
1101}
1102
1103static bool intel_pt_first_wrap(u64 *data, size_t buf_size)
1104{
1105        int i, a, b;
1106
1107        b = buf_size >> 3;
1108        a = b - 512;
1109        if (a < 0)
1110                a = 0;
1111
1112        for (i = a; i < b; i++) {
1113                if (data[i])
1114                        return true;
1115        }
1116
1117        return false;
1118}
1119
1120static int intel_pt_find_snapshot(struct auxtrace_record *itr, int idx,
1121                                  struct auxtrace_mmap *mm, unsigned char *data,
1122                                  u64 *head, u64 *old)
1123{
1124        struct intel_pt_recording *ptr =
1125                        container_of(itr, struct intel_pt_recording, itr);
1126        bool wrapped;
1127        int err;
1128
1129        pr_debug3("%s: mmap index %d old head %zu new head %zu\n",
1130                  __func__, idx, (size_t)*old, (size_t)*head);
1131
1132        err = intel_pt_snapshot_init(ptr, mm->len);
1133        if (err)
1134                goto out_err;
1135
1136        if (idx >= ptr->snapshot_ref_cnt) {
1137                err = intel_pt_alloc_snapshot_refs(ptr, idx);
1138                if (err)
1139                        goto out_err;
1140        }
1141
1142        if (ptr->snapshot_ref_buf_size) {
1143                if (!ptr->snapshot_refs[idx].ref_buf) {
1144                        err = intel_pt_alloc_snapshot_ref(ptr, idx, mm->len);
1145                        if (err)
1146                                goto out_err;
1147                }
1148                wrapped = intel_pt_wrapped(ptr, idx, mm, data, *head);
1149        } else {
1150                wrapped = ptr->snapshot_refs[idx].wrapped;
1151                if (!wrapped && intel_pt_first_wrap((u64 *)data, mm->len)) {
1152                        ptr->snapshot_refs[idx].wrapped = true;
1153                        wrapped = true;
1154                }
1155        }
1156
1157        /*
1158         * In full trace mode 'head' continually increases.  However in snapshot
1159         * mode 'head' is an offset within the buffer.  Here 'old' and 'head'
1160         * are adjusted to match the full trace case which expects that 'old' is
1161         * always less than 'head'.
1162         */
1163        if (wrapped) {
1164                *old = *head;
1165                *head += mm->len;
1166        } else {
1167                if (mm->mask)
1168                        *old &= mm->mask;
1169                else
1170                        *old %= mm->len;
1171                if (*old > *head)
1172                        *head += mm->len;
1173        }
1174
1175        pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n",
1176                  __func__, wrapped ? "" : "not ", (size_t)*old, (size_t)*head);
1177
1178        return 0;
1179
1180out_err:
1181        pr_err("%s: failed, error %d\n", __func__, err);
1182        return err;
1183}
1184
1185static u64 intel_pt_reference(struct auxtrace_record *itr __maybe_unused)
1186{
1187        return rdtsc();
1188}
1189
1190struct auxtrace_record *intel_pt_recording_init(int *err)
1191{
1192        struct perf_pmu *intel_pt_pmu = perf_pmu__find(INTEL_PT_PMU_NAME);
1193        struct intel_pt_recording *ptr;
1194
1195        if (!intel_pt_pmu)
1196                return NULL;
1197
1198        if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) {
1199                *err = -errno;
1200                return NULL;
1201        }
1202
1203        ptr = zalloc(sizeof(struct intel_pt_recording));
1204        if (!ptr) {
1205                *err = -ENOMEM;
1206                return NULL;
1207        }
1208
1209        ptr->intel_pt_pmu = intel_pt_pmu;
1210        ptr->itr.pmu = intel_pt_pmu;
1211        ptr->itr.recording_options = intel_pt_recording_options;
1212        ptr->itr.info_priv_size = intel_pt_info_priv_size;
1213        ptr->itr.info_fill = intel_pt_info_fill;
1214        ptr->itr.free = intel_pt_recording_free;
1215        ptr->itr.snapshot_start = intel_pt_snapshot_start;
1216        ptr->itr.snapshot_finish = intel_pt_snapshot_finish;
1217        ptr->itr.find_snapshot = intel_pt_find_snapshot;
1218        ptr->itr.parse_snapshot_options = intel_pt_parse_snapshot_options;
1219        ptr->itr.reference = intel_pt_reference;
1220        ptr->itr.read_finish = auxtrace_record__read_finish;
1221        /*
1222         * Decoding starts at a PSB packet. Minimum PSB period is 2K so 4K
1223         * should give at least 1 PSB per sample.
1224         */
1225        ptr->itr.default_aux_sample_size = 4096;
1226        return &ptr->itr;
1227}
1228