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

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