root/tools/perf/arch/arm/util/cs-etm.c

DEFINITIONS

1. cs_etm_set_context_id
2. cs_etm_set_timestamp
3. cs_etm_set_option
4. cs_etm_parse_snapshot_options
5. cs_etm_set_sink_attr
6. cs_etm_recording_options
7. cs_etm_get_config
8. cs_etmv4_get_config
9. cs_etm_info_priv_size
10. cs_etm_is_etmv4
11. cs_etm_get_ro
12. cs_etm_get_metadata
13. cs_etm_info_fill
14. cs_etm_alloc_wrapped_array
15. cs_etm_buffer_has_wrapped
16. cs_etm_find_snapshot
17. cs_etm_snapshot_start
18. cs_etm_snapshot_finish
19. cs_etm_reference
20. cs_etm_recording_free
21. cs_etm_read_finish
22. cs_etm_record_init

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright(C) 2015 Linaro Limited. All rights reserved.
   4  * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
   5  */
   6 
   7 #include <api/fs/fs.h>
   8 #include <linux/bits.h>
   9 #include <linux/bitops.h>
  10 #include <linux/compiler.h>
  11 #include <linux/coresight-pmu.h>
  12 #include <linux/kernel.h>
  13 #include <linux/log2.h>
  14 #include <linux/string.h>
  15 #include <linux/types.h>
  16 #include <linux/zalloc.h>
  17 
  18 #include "cs-etm.h"
  19 #include "../../util/debug.h"
  20 #include "../../util/record.h"
  21 #include "../../util/auxtrace.h"
  22 #include "../../util/cpumap.h"
  23 #include "../../util/event.h"
  24 #include "../../util/evlist.h"
  25 #include "../../util/evsel.h"
  26 #include "../../util/evsel_config.h"
  27 #include "../../util/pmu.h"
  28 #include "../../util/cs-etm.h"
  29 #include <internal/lib.h> // page_size
  30 #include "../../util/session.h"
  31 
  32 #include <errno.h>
  33 #include <stdlib.h>
  34 #include <sys/stat.h>
  35 
  36 struct cs_etm_recording {
  37         struct auxtrace_record  itr;
  38         struct perf_pmu         *cs_etm_pmu;
  39         struct evlist           *evlist;
  40         int                     wrapped_cnt;
  41         bool                    *wrapped;
  42         bool                    snapshot_mode;
  43         size_t                  snapshot_size;
  44 };
  45 
  46 static const char *metadata_etmv3_ro[CS_ETM_PRIV_MAX] = {
  47         [CS_ETM_ETMCCER]        = "mgmt/etmccer",
  48         [CS_ETM_ETMIDR]         = "mgmt/etmidr",
  49 };
  50 
  51 static const char *metadata_etmv4_ro[CS_ETMV4_PRIV_MAX] = {
  52         [CS_ETMV4_TRCIDR0]              = "trcidr/trcidr0",
  53         [CS_ETMV4_TRCIDR1]              = "trcidr/trcidr1",
  54         [CS_ETMV4_TRCIDR2]              = "trcidr/trcidr2",
  55         [CS_ETMV4_TRCIDR8]              = "trcidr/trcidr8",
  56         [CS_ETMV4_TRCAUTHSTATUS]        = "mgmt/trcauthstatus",
  57 };
  58 
  59 static bool cs_etm_is_etmv4(struct auxtrace_record *itr, int cpu);
  60 
  61 static int cs_etm_set_context_id(struct auxtrace_record *itr,
  62                                  struct evsel *evsel, int cpu)
  63 {
  64         struct cs_etm_recording *ptr;
  65         struct perf_pmu *cs_etm_pmu;
  66         char path[PATH_MAX];
  67         int err = -EINVAL;
  68         u32 val;
  69 
  70         ptr = container_of(itr, struct cs_etm_recording, itr);
  71         cs_etm_pmu = ptr->cs_etm_pmu;
  72 
  73         if (!cs_etm_is_etmv4(itr, cpu))
  74                 goto out;
  75 
  76         /* Get a handle on TRCIRD2 */
  77         snprintf(path, PATH_MAX, "cpu%d/%s",
  78                  cpu, metadata_etmv4_ro[CS_ETMV4_TRCIDR2]);
  79         err = perf_pmu__scan_file(cs_etm_pmu, path, "%x", &val);
  80 
  81         /* There was a problem reading the file, bailing out */
  82         if (err != 1) {
  83                 pr_err("%s: can't read file %s\n",
  84                        CORESIGHT_ETM_PMU_NAME, path);
  85                 goto out;
  86         }
  87 
  88         /*
  89          * TRCIDR2.CIDSIZE, bit [9-5], indicates whether contextID tracing
  90          * is supported:
  91          *  0b00000 Context ID tracing is not supported.
  92          *  0b00100 Maximum of 32-bit Context ID size.
  93          *  All other values are reserved.
  94          */
  95         val = BMVAL(val, 5, 9);
  96         if (!val || val != 0x4) {
  97                 err = -EINVAL;
  98                 goto out;
  99         }
 100 
 101         /* All good, let the kernel know */
 102         evsel->core.attr.config |= (1 << ETM_OPT_CTXTID);
 103         err = 0;
 104 
 105 out:
 106 
 107         return err;
 108 }
 109 
 110 static int cs_etm_set_timestamp(struct auxtrace_record *itr,
 111                                 struct evsel *evsel, int cpu)
 112 {
 113         struct cs_etm_recording *ptr;
 114         struct perf_pmu *cs_etm_pmu;
 115         char path[PATH_MAX];
 116         int err = -EINVAL;
 117         u32 val;
 118 
 119         ptr = container_of(itr, struct cs_etm_recording, itr);
 120         cs_etm_pmu = ptr->cs_etm_pmu;
 121 
 122         if (!cs_etm_is_etmv4(itr, cpu))
 123                 goto out;
 124 
 125         /* Get a handle on TRCIRD0 */
 126         snprintf(path, PATH_MAX, "cpu%d/%s",
 127                  cpu, metadata_etmv4_ro[CS_ETMV4_TRCIDR0]);
 128         err = perf_pmu__scan_file(cs_etm_pmu, path, "%x", &val);
 129 
 130         /* There was a problem reading the file, bailing out */
 131         if (err != 1) {
 132                 pr_err("%s: can't read file %s\n",
 133                        CORESIGHT_ETM_PMU_NAME, path);
 134                 goto out;
 135         }
 136 
 137         /*
 138          * TRCIDR0.TSSIZE, bit [28-24], indicates whether global timestamping
 139          * is supported:
 140          *  0b00000 Global timestamping is not implemented
 141          *  0b00110 Implementation supports a maximum timestamp of 48bits.
 142          *  0b01000 Implementation supports a maximum timestamp of 64bits.
 143          */
 144         val &= GENMASK(28, 24);
 145         if (!val) {
 146                 err = -EINVAL;
 147                 goto out;
 148         }
 149 
 150         /* All good, let the kernel know */
 151         evsel->core.attr.config |= (1 << ETM_OPT_TS);
 152         err = 0;
 153 
 154 out:
 155         return err;
 156 }
 157 
 158 static int cs_etm_set_option(struct auxtrace_record *itr,
 159                              struct evsel *evsel, u32 option)
 160 {
 161         int i, err = -EINVAL;
 162         struct perf_cpu_map *event_cpus = evsel->evlist->core.cpus;
 163         struct perf_cpu_map *online_cpus = perf_cpu_map__new(NULL);
 164 
 165         /* Set option of each CPU we have */
 166         for (i = 0; i < cpu__max_cpu(); i++) {
 167                 if (!cpu_map__has(event_cpus, i) ||
 168                     !cpu_map__has(online_cpus, i))
 169                         continue;
 170 
 171                 if (option & ETM_OPT_CTXTID) {
 172                         err = cs_etm_set_context_id(itr, evsel, i);
 173                         if (err)
 174                                 goto out;
 175                 }
 176                 if (option & ETM_OPT_TS) {
 177                         err = cs_etm_set_timestamp(itr, evsel, i);
 178                         if (err)
 179                                 goto out;
 180                 }
 181                 if (option & ~(ETM_OPT_CTXTID | ETM_OPT_TS))
 182                         /* Nothing else is currently supported */
 183                         goto out;
 184         }
 185 
 186         err = 0;
 187 out:
 188         perf_cpu_map__put(online_cpus);
 189         return err;
 190 }
 191 
 192 static int cs_etm_parse_snapshot_options(struct auxtrace_record *itr,
 193                                          struct record_opts *opts,
 194                                          const char *str)
 195 {
 196         struct cs_etm_recording *ptr =
 197                                 container_of(itr, struct cs_etm_recording, itr);
 198         unsigned long long snapshot_size = 0;
 199         char *endptr;
 200 
 201         if (str) {
 202                 snapshot_size = strtoull(str, &endptr, 0);
 203                 if (*endptr || snapshot_size > SIZE_MAX)
 204                         return -1;
 205         }
 206 
 207         opts->auxtrace_snapshot_mode = true;
 208         opts->auxtrace_snapshot_size = snapshot_size;
 209         ptr->snapshot_size = snapshot_size;
 210 
 211         return 0;
 212 }
 213 
 214 static int cs_etm_set_sink_attr(struct perf_pmu *pmu,
 215                                 struct evsel *evsel)
 216 {
 217         char msg[BUFSIZ], path[PATH_MAX], *sink;
 218         struct perf_evsel_config_term *term;
 219         int ret = -EINVAL;
 220         u32 hash;
 221 
 222         if (evsel->core.attr.config2 & GENMASK(31, 0))
 223                 return 0;
 224 
 225         list_for_each_entry(term, &evsel->config_terms, list) {
 226                 if (term->type != PERF_EVSEL__CONFIG_TERM_DRV_CFG)
 227                         continue;
 228 
 229                 sink = term->val.drv_cfg;
 230                 snprintf(path, PATH_MAX, "sinks/%s", sink);
 231 
 232                 ret = perf_pmu__scan_file(pmu, path, "%x", &hash);
 233                 if (ret != 1) {
 234                         pr_err("failed to set sink \"%s\" on event %s with %d (%s)\n",
 235                                sink, perf_evsel__name(evsel), errno,
 236                                str_error_r(errno, msg, sizeof(msg)));
 237                         return ret;
 238                 }
 239 
 240                 evsel->core.attr.config2 |= hash;
 241                 return 0;
 242         }
 243 
 244         /*
 245          * No sink was provided on the command line - for _now_ treat
 246          * this as an error.
 247          */
 248         return ret;
 249 }
 250 
 251 static int cs_etm_recording_options(struct auxtrace_record *itr,
 252                                     struct evlist *evlist,
 253                                     struct record_opts *opts)
 254 {
 255         int ret;
 256         struct cs_etm_recording *ptr =
 257                                 container_of(itr, struct cs_etm_recording, itr);
 258         struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
 259         struct evsel *evsel, *cs_etm_evsel = NULL;
 260         struct perf_cpu_map *cpus = evlist->core.cpus;
 261         bool privileged = perf_event_paranoid_check(-1);
 262         int err = 0;
 263 
 264         ptr->evlist = evlist;
 265         ptr->snapshot_mode = opts->auxtrace_snapshot_mode;
 266 
 267         if (perf_can_record_switch_events())
 268                 opts->record_switch_events = true;
 269 
 270         evlist__for_each_entry(evlist, evsel) {
 271                 if (evsel->core.attr.type == cs_etm_pmu->type) {
 272                         if (cs_etm_evsel) {
 273                                 pr_err("There may be only one %s event\n",
 274                                        CORESIGHT_ETM_PMU_NAME);
 275                                 return -EINVAL;
 276                         }
 277                         evsel->core.attr.freq = 0;
 278                         evsel->core.attr.sample_period = 1;
 279                         cs_etm_evsel = evsel;
 280                         opts->full_auxtrace = true;
 281                 }
 282         }
 283 
 284         /* no need to continue if at least one event of interest was found */
 285         if (!cs_etm_evsel)
 286                 return 0;
 287 
 288         ret = cs_etm_set_sink_attr(cs_etm_pmu, cs_etm_evsel);
 289         if (ret)
 290                 return ret;
 291 
 292         if (opts->use_clockid) {
 293                 pr_err("Cannot use clockid (-k option) with %s\n",
 294                        CORESIGHT_ETM_PMU_NAME);
 295                 return -EINVAL;
 296         }
 297 
 298         /* we are in snapshot mode */
 299         if (opts->auxtrace_snapshot_mode) {
 300                 /*
 301                  * No size were given to '-S' or '-m,', so go with
 302                  * the default
 303                  */
 304                 if (!opts->auxtrace_snapshot_size &&
 305                     !opts->auxtrace_mmap_pages) {
 306                         if (privileged) {
 307                                 opts->auxtrace_mmap_pages = MiB(4) / page_size;
 308                         } else {
 309                                 opts->auxtrace_mmap_pages =
 310                                                         KiB(128) / page_size;
 311                                 if (opts->mmap_pages == UINT_MAX)
 312                                         opts->mmap_pages = KiB(256) / page_size;
 313                         }
 314                 } else if (!opts->auxtrace_mmap_pages && !privileged &&
 315                                                 opts->mmap_pages == UINT_MAX) {
 316                         opts->mmap_pages = KiB(256) / page_size;
 317                 }
 318 
 319                 /*
 320                  * '-m,xyz' was specified but no snapshot size, so make the
 321                  * snapshot size as big as the auxtrace mmap area.
 322                  */
 323                 if (!opts->auxtrace_snapshot_size) {
 324                         opts->auxtrace_snapshot_size =
 325                                 opts->auxtrace_mmap_pages * (size_t)page_size;
 326                 }
 327 
 328                 /*
 329                  * -Sxyz was specified but no auxtrace mmap area, so make the
 330                  * auxtrace mmap area big enough to fit the requested snapshot
 331                  * size.
 332                  */
 333                 if (!opts->auxtrace_mmap_pages) {
 334                         size_t sz = opts->auxtrace_snapshot_size;
 335 
 336                         sz = round_up(sz, page_size) / page_size;
 337                         opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
 338                 }
 339 
 340                 /* Snapshost size can't be bigger than the auxtrace area */
 341                 if (opts->auxtrace_snapshot_size >
 342                                 opts->auxtrace_mmap_pages * (size_t)page_size) {
 343                         pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
 344                                opts->auxtrace_snapshot_size,
 345                                opts->auxtrace_mmap_pages * (size_t)page_size);
 346                         return -EINVAL;
 347                 }
 348 
 349                 /* Something went wrong somewhere - this shouldn't happen */
 350                 if (!opts->auxtrace_snapshot_size ||
 351                     !opts->auxtrace_mmap_pages) {
 352                         pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
 353                         return -EINVAL;
 354                 }
 355         }
 356 
 357         /* We are in full trace mode but '-m,xyz' wasn't specified */
 358         if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
 359                 if (privileged) {
 360                         opts->auxtrace_mmap_pages = MiB(4) / page_size;
 361                 } else {
 362                         opts->auxtrace_mmap_pages = KiB(128) / page_size;
 363                         if (opts->mmap_pages == UINT_MAX)
 364                                 opts->mmap_pages = KiB(256) / page_size;
 365                 }
 366 
 367         }
 368 
 369         /* Validate auxtrace_mmap_pages provided by user */
 370         if (opts->auxtrace_mmap_pages) {
 371                 unsigned int max_page = (KiB(128) / page_size);
 372                 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
 373 
 374                 if (!privileged &&
 375                     opts->auxtrace_mmap_pages > max_page) {
 376                         opts->auxtrace_mmap_pages = max_page;
 377                         pr_err("auxtrace too big, truncating to %d\n",
 378                                max_page);
 379                 }
 380 
 381                 if (!is_power_of_2(sz)) {
 382                         pr_err("Invalid mmap size for %s: must be a power of 2\n",
 383                                CORESIGHT_ETM_PMU_NAME);
 384                         return -EINVAL;
 385                 }
 386         }
 387 
 388         if (opts->auxtrace_snapshot_mode)
 389                 pr_debug2("%s snapshot size: %zu\n", CORESIGHT_ETM_PMU_NAME,
 390                           opts->auxtrace_snapshot_size);
 391 
 392         /*
 393          * To obtain the auxtrace buffer file descriptor, the auxtrace
 394          * event must come first.
 395          */
 396         perf_evlist__to_front(evlist, cs_etm_evsel);
 397 
 398         /*
 399          * In the case of per-cpu mmaps, we need the CPU on the
 400          * AUX event.  We also need the contextID in order to be notified
 401          * when a context switch happened.
 402          */
 403         if (!perf_cpu_map__empty(cpus)) {
 404                 perf_evsel__set_sample_bit(cs_etm_evsel, CPU);
 405 
 406                 err = cs_etm_set_option(itr, cs_etm_evsel,
 407                                         ETM_OPT_CTXTID | ETM_OPT_TS);
 408                 if (err)
 409                         goto out;
 410         }
 411 
 412         /* Add dummy event to keep tracking */
 413         if (opts->full_auxtrace) {
 414                 struct evsel *tracking_evsel;
 415 
 416                 err = parse_events(evlist, "dummy:u", NULL);
 417                 if (err)
 418                         goto out;
 419 
 420                 tracking_evsel = evlist__last(evlist);
 421                 perf_evlist__set_tracking_event(evlist, tracking_evsel);
 422 
 423                 tracking_evsel->core.attr.freq = 0;
 424                 tracking_evsel->core.attr.sample_period = 1;
 425 
 426                 /* In per-cpu case, always need the time of mmap events etc */
 427                 if (!perf_cpu_map__empty(cpus))
 428                         perf_evsel__set_sample_bit(tracking_evsel, TIME);
 429         }
 430 
 431 out:
 432         return err;
 433 }
 434 
 435 static u64 cs_etm_get_config(struct auxtrace_record *itr)
 436 {
 437         u64 config = 0;
 438         struct cs_etm_recording *ptr =
 439                         container_of(itr, struct cs_etm_recording, itr);
 440         struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
 441         struct evlist *evlist = ptr->evlist;
 442         struct evsel *evsel;
 443 
 444         evlist__for_each_entry(evlist, evsel) {
 445                 if (evsel->core.attr.type == cs_etm_pmu->type) {
 446                         /*
 447                          * Variable perf_event_attr::config is assigned to
 448                          * ETMv3/PTM.  The bit fields have been made to match
 449                          * the ETMv3.5 ETRMCR register specification.  See the
 450                          * PMU_FORMAT_ATTR() declarations in
 451                          * drivers/hwtracing/coresight/coresight-perf.c for
 452                          * details.
 453                          */
 454                         config = evsel->core.attr.config;
 455                         break;
 456                 }
 457         }
 458 
 459         return config;
 460 }
 461 
 462 #ifndef BIT
 463 #define BIT(N) (1UL << (N))
 464 #endif
 465 
 466 static u64 cs_etmv4_get_config(struct auxtrace_record *itr)
 467 {
 468         u64 config = 0;
 469         u64 config_opts = 0;
 470 
 471         /*
 472          * The perf event variable config bits represent both
 473          * the command line options and register programming
 474          * bits in ETMv3/PTM. For ETMv4 we must remap options
 475          * to real bits
 476          */
 477         config_opts = cs_etm_get_config(itr);
 478         if (config_opts & BIT(ETM_OPT_CYCACC))
 479                 config |= BIT(ETM4_CFG_BIT_CYCACC);
 480         if (config_opts & BIT(ETM_OPT_CTXTID))
 481                 config |= BIT(ETM4_CFG_BIT_CTXTID);
 482         if (config_opts & BIT(ETM_OPT_TS))
 483                 config |= BIT(ETM4_CFG_BIT_TS);
 484         if (config_opts & BIT(ETM_OPT_RETSTK))
 485                 config |= BIT(ETM4_CFG_BIT_RETSTK);
 486 
 487         return config;
 488 }
 489 
 490 static size_t
 491 cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
 492                       struct evlist *evlist __maybe_unused)
 493 {
 494         int i;
 495         int etmv3 = 0, etmv4 = 0;
 496         struct perf_cpu_map *event_cpus = evlist->core.cpus;
 497         struct perf_cpu_map *online_cpus = perf_cpu_map__new(NULL);
 498 
 499         /* cpu map is not empty, we have specific CPUs to work with */
 500         if (!perf_cpu_map__empty(event_cpus)) {
 501                 for (i = 0; i < cpu__max_cpu(); i++) {
 502                         if (!cpu_map__has(event_cpus, i) ||
 503                             !cpu_map__has(online_cpus, i))
 504                                 continue;
 505 
 506                         if (cs_etm_is_etmv4(itr, i))
 507                                 etmv4++;
 508                         else
 509                                 etmv3++;
 510                 }
 511         } else {
 512                 /* get configuration for all CPUs in the system */
 513                 for (i = 0; i < cpu__max_cpu(); i++) {
 514                         if (!cpu_map__has(online_cpus, i))
 515                                 continue;
 516 
 517                         if (cs_etm_is_etmv4(itr, i))
 518                                 etmv4++;
 519                         else
 520                                 etmv3++;
 521                 }
 522         }
 523 
 524         perf_cpu_map__put(online_cpus);
 525 
 526         return (CS_ETM_HEADER_SIZE +
 527                (etmv4 * CS_ETMV4_PRIV_SIZE) +
 528                (etmv3 * CS_ETMV3_PRIV_SIZE));
 529 }
 530 
 531 static bool cs_etm_is_etmv4(struct auxtrace_record *itr, int cpu)
 532 {
 533         bool ret = false;
 534         char path[PATH_MAX];
 535         int scan;
 536         unsigned int val;
 537         struct cs_etm_recording *ptr =
 538                         container_of(itr, struct cs_etm_recording, itr);
 539         struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
 540 
 541         /* Take any of the RO files for ETMv4 and see if it present */
 542         snprintf(path, PATH_MAX, "cpu%d/%s",
 543                  cpu, metadata_etmv4_ro[CS_ETMV4_TRCIDR0]);
 544         scan = perf_pmu__scan_file(cs_etm_pmu, path, "%x", &val);
 545 
 546         /* The file was read successfully, we have a winner */
 547         if (scan == 1)
 548                 ret = true;
 549 
 550         return ret;
 551 }
 552 
 553 static int cs_etm_get_ro(struct perf_pmu *pmu, int cpu, const char *path)
 554 {
 555         char pmu_path[PATH_MAX];
 556         int scan;
 557         unsigned int val = 0;
 558 
 559         /* Get RO metadata from sysfs */
 560         snprintf(pmu_path, PATH_MAX, "cpu%d/%s", cpu, path);
 561 
 562         scan = perf_pmu__scan_file(pmu, pmu_path, "%x", &val);
 563         if (scan != 1)
 564                 pr_err("%s: error reading: %s\n", __func__, pmu_path);
 565 
 566         return val;
 567 }
 568 
 569 static void cs_etm_get_metadata(int cpu, u32 *offset,
 570                                 struct auxtrace_record *itr,
 571                                 struct perf_record_auxtrace_info *info)
 572 {
 573         u32 increment;
 574         u64 magic;
 575         struct cs_etm_recording *ptr =
 576                         container_of(itr, struct cs_etm_recording, itr);
 577         struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
 578 
 579         /* first see what kind of tracer this cpu is affined to */
 580         if (cs_etm_is_etmv4(itr, cpu)) {
 581                 magic = __perf_cs_etmv4_magic;
 582                 /* Get trace configuration register */
 583                 info->priv[*offset + CS_ETMV4_TRCCONFIGR] =
 584                                                 cs_etmv4_get_config(itr);
 585                 /* Get traceID from the framework */
 586                 info->priv[*offset + CS_ETMV4_TRCTRACEIDR] =
 587                                                 coresight_get_trace_id(cpu);
 588                 /* Get read-only information from sysFS */
 589                 info->priv[*offset + CS_ETMV4_TRCIDR0] =
 590                         cs_etm_get_ro(cs_etm_pmu, cpu,
 591                                       metadata_etmv4_ro[CS_ETMV4_TRCIDR0]);
 592                 info->priv[*offset + CS_ETMV4_TRCIDR1] =
 593                         cs_etm_get_ro(cs_etm_pmu, cpu,
 594                                       metadata_etmv4_ro[CS_ETMV4_TRCIDR1]);
 595                 info->priv[*offset + CS_ETMV4_TRCIDR2] =
 596                         cs_etm_get_ro(cs_etm_pmu, cpu,
 597                                       metadata_etmv4_ro[CS_ETMV4_TRCIDR2]);
 598                 info->priv[*offset + CS_ETMV4_TRCIDR8] =
 599                         cs_etm_get_ro(cs_etm_pmu, cpu,
 600                                       metadata_etmv4_ro[CS_ETMV4_TRCIDR8]);
 601                 info->priv[*offset + CS_ETMV4_TRCAUTHSTATUS] =
 602                         cs_etm_get_ro(cs_etm_pmu, cpu,
 603                                       metadata_etmv4_ro
 604                                       [CS_ETMV4_TRCAUTHSTATUS]);
 605 
 606                 /* How much space was used */
 607                 increment = CS_ETMV4_PRIV_MAX;
 608         } else {
 609                 magic = __perf_cs_etmv3_magic;
 610                 /* Get configuration register */
 611                 info->priv[*offset + CS_ETM_ETMCR] = cs_etm_get_config(itr);
 612                 /* Get traceID from the framework */
 613                 info->priv[*offset + CS_ETM_ETMTRACEIDR] =
 614                                                 coresight_get_trace_id(cpu);
 615                 /* Get read-only information from sysFS */
 616                 info->priv[*offset + CS_ETM_ETMCCER] =
 617                         cs_etm_get_ro(cs_etm_pmu, cpu,
 618                                       metadata_etmv3_ro[CS_ETM_ETMCCER]);
 619                 info->priv[*offset + CS_ETM_ETMIDR] =
 620                         cs_etm_get_ro(cs_etm_pmu, cpu,
 621                                       metadata_etmv3_ro[CS_ETM_ETMIDR]);
 622 
 623                 /* How much space was used */
 624                 increment = CS_ETM_PRIV_MAX;
 625         }
 626 
 627         /* Build generic header portion */
 628         info->priv[*offset + CS_ETM_MAGIC] = magic;
 629         info->priv[*offset + CS_ETM_CPU] = cpu;
 630         /* Where the next CPU entry should start from */
 631         *offset += increment;
 632 }
 633 
 634 static int cs_etm_info_fill(struct auxtrace_record *itr,
 635                             struct perf_session *session,
 636                             struct perf_record_auxtrace_info *info,
 637                             size_t priv_size)
 638 {
 639         int i;
 640         u32 offset;
 641         u64 nr_cpu, type;
 642         struct perf_cpu_map *cpu_map;
 643         struct perf_cpu_map *event_cpus = session->evlist->core.cpus;
 644         struct perf_cpu_map *online_cpus = perf_cpu_map__new(NULL);
 645         struct cs_etm_recording *ptr =
 646                         container_of(itr, struct cs_etm_recording, itr);
 647         struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
 648 
 649         if (priv_size != cs_etm_info_priv_size(itr, session->evlist))
 650                 return -EINVAL;
 651 
 652         if (!session->evlist->core.nr_mmaps)
 653                 return -EINVAL;
 654 
 655         /* If the cpu_map is empty all online CPUs are involved */
 656         if (perf_cpu_map__empty(event_cpus)) {
 657                 cpu_map = online_cpus;
 658         } else {
 659                 /* Make sure all specified CPUs are online */
 660                 for (i = 0; i < perf_cpu_map__nr(event_cpus); i++) {
 661                         if (cpu_map__has(event_cpus, i) &&
 662                             !cpu_map__has(online_cpus, i))
 663                                 return -EINVAL;
 664                 }
 665 
 666                 cpu_map = event_cpus;
 667         }
 668 
 669         nr_cpu = perf_cpu_map__nr(cpu_map);
 670         /* Get PMU type as dynamically assigned by the core */
 671         type = cs_etm_pmu->type;
 672 
 673         /* First fill out the session header */
 674         info->type = PERF_AUXTRACE_CS_ETM;
 675         info->priv[CS_HEADER_VERSION_0] = 0;
 676         info->priv[CS_PMU_TYPE_CPUS] = type << 32;
 677         info->priv[CS_PMU_TYPE_CPUS] |= nr_cpu;
 678         info->priv[CS_ETM_SNAPSHOT] = ptr->snapshot_mode;
 679 
 680         offset = CS_ETM_SNAPSHOT + 1;
 681 
 682         for (i = 0; i < cpu__max_cpu() && offset < priv_size; i++)
 683                 if (cpu_map__has(cpu_map, i))
 684                         cs_etm_get_metadata(i, &offset, itr, info);
 685 
 686         perf_cpu_map__put(online_cpus);
 687 
 688         return 0;
 689 }
 690 
 691 static int cs_etm_alloc_wrapped_array(struct cs_etm_recording *ptr, int idx)
 692 {
 693         bool *wrapped;
 694         int cnt = ptr->wrapped_cnt;
 695 
 696         /* Make @ptr->wrapped as big as @idx */
 697         while (cnt <= idx)
 698                 cnt++;
 699 
 700         /*
 701          * Free'ed in cs_etm_recording_free().  Using realloc() to avoid
 702          * cross compilation problems where the host's system supports
 703          * reallocarray() but not the target.
 704          */
 705         wrapped = realloc(ptr->wrapped, cnt * sizeof(bool));
 706         if (!wrapped)
 707                 return -ENOMEM;
 708 
 709         wrapped[cnt - 1] = false;
 710         ptr->wrapped_cnt = cnt;
 711         ptr->wrapped = wrapped;
 712 
 713         return 0;
 714 }
 715 
 716 static bool cs_etm_buffer_has_wrapped(unsigned char *buffer,
 717                                       size_t buffer_size, u64 head)
 718 {
 719         u64 i, watermark;
 720         u64 *buf = (u64 *)buffer;
 721         size_t buf_size = buffer_size;
 722 
 723         /*
 724          * We want to look the very last 512 byte (chosen arbitrarily) in
 725          * the ring buffer.
 726          */
 727         watermark = buf_size - 512;
 728 
 729         /*
 730          * @head is continuously increasing - if its value is equal or greater
 731          * than the size of the ring buffer, it has wrapped around.
 732          */
 733         if (head >= buffer_size)
 734                 return true;
 735 
 736         /*
 737          * The value of @head is somewhere within the size of the ring buffer.
 738          * This can be that there hasn't been enough data to fill the ring
 739          * buffer yet or the trace time was so long that @head has numerically
 740          * wrapped around.  To find we need to check if we have data at the very
 741          * end of the ring buffer.  We can reliably do this because mmap'ed
 742          * pages are zeroed out and there is a fresh mapping with every new
 743          * session.
 744          */
 745 
 746         /* @head is less than 512 byte from the end of the ring buffer */
 747         if (head > watermark)
 748                 watermark = head;
 749 
 750         /*
 751          * Speed things up by using 64 bit transactions (see "u64 *buf" above)
 752          */
 753         watermark >>= 3;
 754         buf_size >>= 3;
 755 
 756         /*
 757          * If we find trace data at the end of the ring buffer, @head has
 758          * been there and has numerically wrapped around at least once.
 759          */
 760         for (i = watermark; i < buf_size; i++)
 761                 if (buf[i])
 762                         return true;
 763 
 764         return false;
 765 }
 766 
 767 static int cs_etm_find_snapshot(struct auxtrace_record *itr,
 768                                 int idx, struct auxtrace_mmap *mm,
 769                                 unsigned char *data,
 770                                 u64 *head, u64 *old)
 771 {
 772         int err;
 773         bool wrapped;
 774         struct cs_etm_recording *ptr =
 775                         container_of(itr, struct cs_etm_recording, itr);
 776 
 777         /*
 778          * Allocate memory to keep track of wrapping if this is the first
 779          * time we deal with this *mm.
 780          */
 781         if (idx >= ptr->wrapped_cnt) {
 782                 err = cs_etm_alloc_wrapped_array(ptr, idx);
 783                 if (err)
 784                         return err;
 785         }
 786 
 787         /*
 788          * Check to see if *head has wrapped around.  If it hasn't only the
 789          * amount of data between *head and *old is snapshot'ed to avoid
 790          * bloating the perf.data file with zeros.  But as soon as *head has
 791          * wrapped around the entire size of the AUX ring buffer it taken.
 792          */
 793         wrapped = ptr->wrapped[idx];
 794         if (!wrapped && cs_etm_buffer_has_wrapped(data, mm->len, *head)) {
 795                 wrapped = true;
 796                 ptr->wrapped[idx] = true;
 797         }
 798 
 799         pr_debug3("%s: mmap index %d old head %zu new head %zu size %zu\n",
 800                   __func__, idx, (size_t)*old, (size_t)*head, mm->len);
 801 
 802         /* No wrap has occurred, we can just use *head and *old. */
 803         if (!wrapped)
 804                 return 0;
 805 
 806         /*
 807          * *head has wrapped around - adjust *head and *old to pickup the
 808          * entire content of the AUX buffer.
 809          */
 810         if (*head >= mm->len) {
 811                 *old = *head - mm->len;
 812         } else {
 813                 *head += mm->len;
 814                 *old = *head - mm->len;
 815         }
 816 
 817         return 0;
 818 }
 819 
 820 static int cs_etm_snapshot_start(struct auxtrace_record *itr)
 821 {
 822         struct cs_etm_recording *ptr =
 823                         container_of(itr, struct cs_etm_recording, itr);
 824         struct evsel *evsel;
 825 
 826         evlist__for_each_entry(ptr->evlist, evsel) {
 827                 if (evsel->core.attr.type == ptr->cs_etm_pmu->type)
 828                         return evsel__disable(evsel);
 829         }
 830         return -EINVAL;
 831 }
 832 
 833 static int cs_etm_snapshot_finish(struct auxtrace_record *itr)
 834 {
 835         struct cs_etm_recording *ptr =
 836                         container_of(itr, struct cs_etm_recording, itr);
 837         struct evsel *evsel;
 838 
 839         evlist__for_each_entry(ptr->evlist, evsel) {
 840                 if (evsel->core.attr.type == ptr->cs_etm_pmu->type)
 841                         return evsel__enable(evsel);
 842         }
 843         return -EINVAL;
 844 }
 845 
 846 static u64 cs_etm_reference(struct auxtrace_record *itr __maybe_unused)
 847 {
 848         return (((u64) rand() <<  0) & 0x00000000FFFFFFFFull) |
 849                 (((u64) rand() << 32) & 0xFFFFFFFF00000000ull);
 850 }
 851 
 852 static void cs_etm_recording_free(struct auxtrace_record *itr)
 853 {
 854         struct cs_etm_recording *ptr =
 855                         container_of(itr, struct cs_etm_recording, itr);
 856 
 857         zfree(&ptr->wrapped);
 858         free(ptr);
 859 }
 860 
 861 static int cs_etm_read_finish(struct auxtrace_record *itr, int idx)
 862 {
 863         struct cs_etm_recording *ptr =
 864                         container_of(itr, struct cs_etm_recording, itr);
 865         struct evsel *evsel;
 866 
 867         evlist__for_each_entry(ptr->evlist, evsel) {
 868                 if (evsel->core.attr.type == ptr->cs_etm_pmu->type) {
 869                         if (evsel->disabled)
 870                                 return 0;
 871                         return perf_evlist__enable_event_idx(ptr->evlist,
 872                                                              evsel, idx);
 873                 }
 874         }
 875 
 876         return -EINVAL;
 877 }
 878 
 879 struct auxtrace_record *cs_etm_record_init(int *err)
 880 {
 881         struct perf_pmu *cs_etm_pmu;
 882         struct cs_etm_recording *ptr;
 883 
 884         cs_etm_pmu = perf_pmu__find(CORESIGHT_ETM_PMU_NAME);
 885 
 886         if (!cs_etm_pmu) {
 887                 *err = -EINVAL;
 888                 goto out;
 889         }
 890 
 891         ptr = zalloc(sizeof(struct cs_etm_recording));
 892         if (!ptr) {
 893                 *err = -ENOMEM;
 894                 goto out;
 895         }
 896 
 897         ptr->cs_etm_pmu                 = cs_etm_pmu;
 898         ptr->itr.parse_snapshot_options = cs_etm_parse_snapshot_options;
 899         ptr->itr.recording_options      = cs_etm_recording_options;
 900         ptr->itr.info_priv_size         = cs_etm_info_priv_size;
 901         ptr->itr.info_fill              = cs_etm_info_fill;
 902         ptr->itr.find_snapshot          = cs_etm_find_snapshot;
 903         ptr->itr.snapshot_start         = cs_etm_snapshot_start;
 904         ptr->itr.snapshot_finish        = cs_etm_snapshot_finish;
 905         ptr->itr.reference              = cs_etm_reference;
 906         ptr->itr.free                   = cs_etm_recording_free;
 907         ptr->itr.read_finish            = cs_etm_read_finish;
 908 
 909         *err = 0;
 910         return &ptr->itr;
 911 out:
 912         return NULL;
 913 }