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

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