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/coresight-pmu.h>
  21 #include <linux/kernel.h>
  22 #include <linux/log2.h>
  23 #include <linux/types.h>
  24
  25 #include "cs-etm.h"
  26 #include "../../perf.h"
  27 #include "../../util/auxtrace.h"
  28 #include "../../util/cpumap.h"
  29 #include "../../util/evlist.h"
  30 #include "../../util/evsel.h"
  31 #include "../../util/pmu.h"
  32 #include "../../util/thread_map.h"
  33 #include "../../util/cs-etm.h"
  34
  35 #include <stdlib.h>
  36 #include <sys/stat.h>
  37
  38 #define ENABLE_SINK_MAX 128
  39 #define CS_BUS_DEVICE_PATH "/bus/coresight/devices/"
  40
  41 struct cs_etm_recording {
  42         struct auxtrace_record  itr;
  43         struct perf_pmu         *cs_etm_pmu;
  44         struct perf_evlist      *evlist;
  45         bool                    snapshot_mode;
  46         size_t                  snapshot_size;
  47 };
  48
  49 static bool cs_etm_is_etmv4(struct auxtrace_record *itr, int cpu);
  50
  51 static int cs_etm_parse_snapshot_options(struct auxtrace_record *itr,
  52                                          struct record_opts *opts,
  53                                          const char *str)
  54 {
  55         struct cs_etm_recording *ptr =
  56                                 container_of(itr, struct cs_etm_recording, itr);
  57         unsigned long long snapshot_size = 0;
  58         char *endptr;
  59
  60         if (str) {
  61                 snapshot_size = strtoull(str, &endptr, 0);
  62                 if (*endptr || snapshot_size > SIZE_MAX)
  63                         return -1;
  64         }
  65
  66         opts->auxtrace_snapshot_mode = true;
  67         opts->auxtrace_snapshot_size = snapshot_size;
  68         ptr->snapshot_size = snapshot_size;
  69
  70         return 0;
  71 }
  72
  73 static int cs_etm_recording_options(struct auxtrace_record *itr,
  74                                     struct perf_evlist *evlist,
  75                                     struct record_opts *opts)
  76 {
  77         struct cs_etm_recording *ptr =
  78                                 container_of(itr, struct cs_etm_recording, itr);
  79         struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
  80         struct perf_evsel *evsel, *cs_etm_evsel = NULL;
  81         const struct cpu_map *cpus = evlist->cpus;
  82         bool privileged = (geteuid() == 0 || perf_event_paranoid() < 0);
  83
  84         ptr->evlist = evlist;
  85         ptr->snapshot_mode = opts->auxtrace_snapshot_mode;
  86
  87         evlist__for_each_entry(evlist, evsel) {
  88                 if (evsel->attr.type == cs_etm_pmu->type) {
  89                         if (cs_etm_evsel) {
  90                                 pr_err("There may be only one %s event\n",
  91                                        CORESIGHT_ETM_PMU_NAME);
  92                                 return -EINVAL;
  93                         }
  94                         evsel->attr.freq = 0;
  95                         evsel->attr.sample_period = 1;
  96                         cs_etm_evsel = evsel;
  97                         opts->full_auxtrace = true;
  98                 }
  99         }
 100
 101         /* no need to continue if at least one event of interest was found */
 102         if (!cs_etm_evsel)
 103                 return 0;
 104
 105         if (opts->use_clockid) {
 106                 pr_err("Cannot use clockid (-k option) with %s\n",
 107                        CORESIGHT_ETM_PMU_NAME);
 108                 return -EINVAL;
 109         }
 110
 111         /* we are in snapshot mode */
 112         if (opts->auxtrace_snapshot_mode) {
 113                 /*
 114                  * No size were given to '-S' or '-m,', so go with
 115                  * the default
 116                  */
 117                 if (!opts->auxtrace_snapshot_size &&
 118                     !opts->auxtrace_mmap_pages) {
 119                         if (privileged) {
 120                                 opts->auxtrace_mmap_pages = MiB(4) / page_size;
 121                         } else {
 122                                 opts->auxtrace_mmap_pages =
 123                                                         KiB(128) / page_size;
 124                                 if (opts->mmap_pages == UINT_MAX)
 125                                         opts->mmap_pages = KiB(256) / page_size;
 126                         }
 127                 } else if (!opts->auxtrace_mmap_pages && !privileged &&
 128                                                 opts->mmap_pages == UINT_MAX) {
 129                         opts->mmap_pages = KiB(256) / page_size;
 130                 }
 131
 132                 /*
 133                  * '-m,xyz' was specified but no snapshot size, so make the
 134                  * snapshot size as big as the auxtrace mmap area.
 135                  */
 136                 if (!opts->auxtrace_snapshot_size) {
 137                         opts->auxtrace_snapshot_size =
 138                                 opts->auxtrace_mmap_pages * (size_t)page_size;
 139                 }
 140
 141                 /*
 142                  * -Sxyz was specified but no auxtrace mmap area, so make the
 143                  * auxtrace mmap area big enough to fit the requested snapshot
 144                  * size.
 145                  */
 146                 if (!opts->auxtrace_mmap_pages) {
 147                         size_t sz = opts->auxtrace_snapshot_size;
 148
 149                         sz = round_up(sz, page_size) / page_size;
 150                         opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
 151                 }
 152
 153                 /* Snapshost size can't be bigger than the auxtrace area */
 154                 if (opts->auxtrace_snapshot_size >
 155                                 opts->auxtrace_mmap_pages * (size_t)page_size) {
 156                         pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
 157                                opts->auxtrace_snapshot_size,
 158                                opts->auxtrace_mmap_pages * (size_t)page_size);
 159                         return -EINVAL;
 160                 }
 161
 162                 /* Something went wrong somewhere - this shouldn't happen */
 163                 if (!opts->auxtrace_snapshot_size ||
 164                     !opts->auxtrace_mmap_pages) {
 165                         pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
 166                         return -EINVAL;
 167                 }
 168         }
 169
 170         /* We are in full trace mode but '-m,xyz' wasn't specified */
 171         if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
 172                 if (privileged) {
 173                         opts->auxtrace_mmap_pages = MiB(4) / page_size;
 174                 } else {
 175                         opts->auxtrace_mmap_pages = KiB(128) / page_size;
 176                         if (opts->mmap_pages == UINT_MAX)
 177                                 opts->mmap_pages = KiB(256) / page_size;
 178                 }
 179
 180         }
 181
 182         /* Validate auxtrace_mmap_pages provided by user */
 183         if (opts->auxtrace_mmap_pages) {
 184                 unsigned int max_page = (KiB(128) / page_size);
 185                 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
 186
 187                 if (!privileged &&
 188                     opts->auxtrace_mmap_pages > max_page) {
 189                         opts->auxtrace_mmap_pages = max_page;
 190                         pr_err("auxtrace too big, truncating to %d\n",
 191                                max_page);
 192                 }
 193
 194                 if (!is_power_of_2(sz)) {
 195                         pr_err("Invalid mmap size for %s: must be a power of 2\n",
 196                                CORESIGHT_ETM_PMU_NAME);
 197                         return -EINVAL;
 198                 }
 199         }
 200
 201         if (opts->auxtrace_snapshot_mode)
 202                 pr_debug2("%s snapshot size: %zu\n", CORESIGHT_ETM_PMU_NAME,
 203                           opts->auxtrace_snapshot_size);
 204
 205         if (cs_etm_evsel) {
 206                 /*
 207                  * To obtain the auxtrace buffer file descriptor, the auxtrace
 208                  * event must come first.
 209                  */
 210                 perf_evlist__to_front(evlist, cs_etm_evsel);
 211                 /*
 212                  * In the case of per-cpu mmaps, we need the CPU on the
 213                  * AUX event.
 214                  */
 215                 if (!cpu_map__empty(cpus))
 216                         perf_evsel__set_sample_bit(cs_etm_evsel, CPU);
 217         }
 218
 219         /* Add dummy event to keep tracking */
 220         if (opts->full_auxtrace) {
 221                 struct perf_evsel *tracking_evsel;
 222                 int err;
 223
 224                 err = parse_events(evlist, "dummy:u", NULL);
 225                 if (err)
 226                         return err;
 227
 228                 tracking_evsel = perf_evlist__last(evlist);
 229                 perf_evlist__set_tracking_event(evlist, tracking_evsel);
 230
 231                 tracking_evsel->attr.freq = 0;
 232                 tracking_evsel->attr.sample_period = 1;
 233
 234                 /* In per-cpu case, always need the time of mmap events etc */
 235                 if (!cpu_map__empty(cpus))
 236                         perf_evsel__set_sample_bit(tracking_evsel, TIME);
 237         }
 238
 239         return 0;
 240 }
 241
 242 static u64 cs_etm_get_config(struct auxtrace_record *itr)
 243 {
 244         u64 config = 0;
 245         struct cs_etm_recording *ptr =
 246                         container_of(itr, struct cs_etm_recording, itr);
 247         struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
 248         struct perf_evlist *evlist = ptr->evlist;
 249         struct perf_evsel *evsel;
 250
 251         evlist__for_each_entry(evlist, evsel) {
 252                 if (evsel->attr.type == cs_etm_pmu->type) {
 253                         /*
 254                          * Variable perf_event_attr::config is assigned to
 255                          * ETMv3/PTM.  The bit fields have been made to match
 256                          * the ETMv3.5 ETRMCR register specification.  See the
 257                          * PMU_FORMAT_ATTR() declarations in
 258                          * drivers/hwtracing/coresight/coresight-perf.c for
 259                          * details.
 260                          */
 261                         config = evsel->attr.config;
 262                         break;
 263                 }
 264         }
 265
 266         return config;
 267 }
 268
 269 static size_t
 270 cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
 271                       struct perf_evlist *evlist __maybe_unused)
 272 {
 273         int i;
 274         int etmv3 = 0, etmv4 = 0;
 275         const struct cpu_map *cpus = evlist->cpus;
 276
 277         /* cpu map is not empty, we have specific CPUs to work with */
 278         if (!cpu_map__empty(cpus)) {
 279                 for (i = 0; i < cpu_map__nr(cpus); i++) {
 280                         if (cs_etm_is_etmv4(itr, cpus->map[i]))
 281                                 etmv4++;
 282                         else
 283                                 etmv3++;
 284                 }
 285         } else {
 286                 /* get configuration for all CPUs in the system */
 287                 for (i = 0; i < cpu__max_cpu(); i++) {
 288                         if (cs_etm_is_etmv4(itr, i))
 289                                 etmv4++;
 290                         else
 291                                 etmv3++;
 292                 }
 293         }
 294
 295         return (CS_ETM_HEADER_SIZE +
 296                (etmv4 * CS_ETMV4_PRIV_SIZE) +
 297                (etmv3 * CS_ETMV3_PRIV_SIZE));
 298 }
 299
 300 static const char *metadata_etmv3_ro[CS_ETM_PRIV_MAX] = {
 301         [CS_ETM_ETMCCER]        = "mgmt/etmccer",
 302         [CS_ETM_ETMIDR]         = "mgmt/etmidr",
 303 };
 304
 305 static const char *metadata_etmv4_ro[CS_ETMV4_PRIV_MAX] = {
 306         [CS_ETMV4_TRCIDR0]              = "trcidr/trcidr0",
 307         [CS_ETMV4_TRCIDR1]              = "trcidr/trcidr1",
 308         [CS_ETMV4_TRCIDR2]              = "trcidr/trcidr2",
 309         [CS_ETMV4_TRCIDR8]              = "trcidr/trcidr8",
 310         [CS_ETMV4_TRCAUTHSTATUS]        = "mgmt/trcauthstatus",
 311 };
 312
 313 static bool cs_etm_is_etmv4(struct auxtrace_record *itr, int cpu)
 314 {
 315         bool ret = false;
 316         char path[PATH_MAX];
 317         int scan;
 318         unsigned int val;
 319         struct cs_etm_recording *ptr =
 320                         container_of(itr, struct cs_etm_recording, itr);
 321         struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
 322
 323         /* Take any of the RO files for ETMv4 and see if it present */
 324         snprintf(path, PATH_MAX, "cpu%d/%s",
 325                  cpu, metadata_etmv4_ro[CS_ETMV4_TRCIDR0]);
 326         scan = perf_pmu__scan_file(cs_etm_pmu, path, "%x", &val);
 327
 328         /* The file was read successfully, we have a winner */
 329         if (scan == 1)
 330                 ret = true;
 331
 332         return ret;
 333 }
 334
 335 static int cs_etm_get_ro(struct perf_pmu *pmu, int cpu, const char *path)
 336 {
 337         char pmu_path[PATH_MAX];
 338         int scan;
 339         unsigned int val = 0;
 340
 341         /* Get RO metadata from sysfs */
 342         snprintf(pmu_path, PATH_MAX, "cpu%d/%s", cpu, path);
 343
 344         scan = perf_pmu__scan_file(pmu, pmu_path, "%x", &val);
 345         if (scan != 1)
 346                 pr_err("%s: error reading: %s\n", __func__, pmu_path);
 347
 348         return val;
 349 }
 350
 351 static void cs_etm_get_metadata(int cpu, u32 *offset,
 352                                 struct auxtrace_record *itr,
 353                                 struct auxtrace_info_event *info)
 354 {
 355         u32 increment;
 356         u64 magic;
 357         struct cs_etm_recording *ptr =
 358                         container_of(itr, struct cs_etm_recording, itr);
 359         struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
 360
 361         /* first see what kind of tracer this cpu is affined to */
 362         if (cs_etm_is_etmv4(itr, cpu)) {
 363                 magic = __perf_cs_etmv4_magic;
 364                 /* Get trace configuration register */
 365                 info->priv[*offset + CS_ETMV4_TRCCONFIGR] =
 366                                                 cs_etm_get_config(itr);
 367                 /* Get traceID from the framework */
 368                 info->priv[*offset + CS_ETMV4_TRCTRACEIDR] =
 369                                                 coresight_get_trace_id(cpu);
 370                 /* Get read-only information from sysFS */
 371                 info->priv[*offset + CS_ETMV4_TRCIDR0] =
 372                         cs_etm_get_ro(cs_etm_pmu, cpu,
 373                                       metadata_etmv4_ro[CS_ETMV4_TRCIDR0]);
 374                 info->priv[*offset + CS_ETMV4_TRCIDR1] =
 375                         cs_etm_get_ro(cs_etm_pmu, cpu,
 376                                       metadata_etmv4_ro[CS_ETMV4_TRCIDR1]);
 377                 info->priv[*offset + CS_ETMV4_TRCIDR2] =
 378                         cs_etm_get_ro(cs_etm_pmu, cpu,
 379                                       metadata_etmv4_ro[CS_ETMV4_TRCIDR2]);
 380                 info->priv[*offset + CS_ETMV4_TRCIDR8] =
 381                         cs_etm_get_ro(cs_etm_pmu, cpu,
 382                                       metadata_etmv4_ro[CS_ETMV4_TRCIDR8]);
 383                 info->priv[*offset + CS_ETMV4_TRCAUTHSTATUS] =
 384                         cs_etm_get_ro(cs_etm_pmu, cpu,
 385                                       metadata_etmv4_ro
 386                                       [CS_ETMV4_TRCAUTHSTATUS]);
 387
 388                 /* How much space was used */
 389                 increment = CS_ETMV4_PRIV_MAX;
 390         } else {
 391                 magic = __perf_cs_etmv3_magic;
 392                 /* Get configuration register */
 393                 info->priv[*offset + CS_ETM_ETMCR] = cs_etm_get_config(itr);
 394                 /* Get traceID from the framework */
 395                 info->priv[*offset + CS_ETM_ETMTRACEIDR] =
 396                                                 coresight_get_trace_id(cpu);
 397                 /* Get read-only information from sysFS */
 398                 info->priv[*offset + CS_ETM_ETMCCER] =
 399                         cs_etm_get_ro(cs_etm_pmu, cpu,
 400                                       metadata_etmv3_ro[CS_ETM_ETMCCER]);
 401                 info->priv[*offset + CS_ETM_ETMIDR] =
 402                         cs_etm_get_ro(cs_etm_pmu, cpu,
 403                                       metadata_etmv3_ro[CS_ETM_ETMIDR]);
 404
 405                 /* How much space was used */
 406                 increment = CS_ETM_PRIV_MAX;
 407         }
 408
 409         /* Build generic header portion */
 410         info->priv[*offset + CS_ETM_MAGIC] = magic;
 411         info->priv[*offset + CS_ETM_CPU] = cpu;
 412         /* Where the next CPU entry should start from */
 413         *offset += increment;
 414 }
 415
 416 static int cs_etm_info_fill(struct auxtrace_record *itr,
 417                             struct perf_session *session,
 418                             struct auxtrace_info_event *info,
 419                             size_t priv_size)
 420 {
 421         int i;
 422         u32 offset;
 423         u64 nr_cpu, type;
 424         const struct cpu_map *cpus = session->evlist->cpus;
 425         struct cs_etm_recording *ptr =
 426                         container_of(itr, struct cs_etm_recording, itr);
 427         struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
 428
 429         if (priv_size != cs_etm_info_priv_size(itr, session->evlist))
 430                 return -EINVAL;
 431
 432         if (!session->evlist->nr_mmaps)
 433                 return -EINVAL;
 434
 435         /* If the cpu_map is empty all CPUs are involved */
 436         nr_cpu = cpu_map__empty(cpus) ? cpu__max_cpu() : cpu_map__nr(cpus);
 437         /* Get PMU type as dynamically assigned by the core */
 438         type = cs_etm_pmu->type;
 439
 440         /* First fill out the session header */
 441         info->type = PERF_AUXTRACE_CS_ETM;
 442         info->priv[CS_HEADER_VERSION_0] = 0;
 443         info->priv[CS_PMU_TYPE_CPUS] = type << 32;
 444         info->priv[CS_PMU_TYPE_CPUS] |= nr_cpu;
 445         info->priv[CS_ETM_SNAPSHOT] = ptr->snapshot_mode;
 446
 447         offset = CS_ETM_SNAPSHOT + 1;
 448
 449         /* cpu map is not empty, we have specific CPUs to work with */
 450         if (!cpu_map__empty(cpus)) {
 451                 for (i = 0; i < cpu_map__nr(cpus) && offset < priv_size; i++)
 452                         cs_etm_get_metadata(cpus->map[i], &offset, itr, info);
 453         } else {
 454                 /* get configuration for all CPUs in the system */
 455                 for (i = 0; i < cpu__max_cpu(); i++)
 456                         cs_etm_get_metadata(i, &offset, itr, info);
 457         }
 458
 459         return 0;
 460 }
 461
 462 static int cs_etm_find_snapshot(struct auxtrace_record *itr __maybe_unused,
 463                                 int idx, struct auxtrace_mmap *mm,
 464                                 unsigned char *data __maybe_unused,
 465                                 u64 *head, u64 *old)
 466 {
 467         pr_debug3("%s: mmap index %d old head %zu new head %zu size %zu\n",
 468                   __func__, idx, (size_t)*old, (size_t)*head, mm->len);
 469
 470         *old = *head;
 471         *head += mm->len;
 472
 473         return 0;
 474 }
 475
 476 static int cs_etm_snapshot_start(struct auxtrace_record *itr)
 477 {
 478         struct cs_etm_recording *ptr =
 479                         container_of(itr, struct cs_etm_recording, itr);
 480         struct perf_evsel *evsel;
 481
 482         evlist__for_each_entry(ptr->evlist, evsel) {
 483                 if (evsel->attr.type == ptr->cs_etm_pmu->type)
 484                         return perf_evsel__disable(evsel);
 485         }
 486         return -EINVAL;
 487 }
 488
 489 static int cs_etm_snapshot_finish(struct auxtrace_record *itr)
 490 {
 491         struct cs_etm_recording *ptr =
 492                         container_of(itr, struct cs_etm_recording, itr);
 493         struct perf_evsel *evsel;
 494
 495         evlist__for_each_entry(ptr->evlist, evsel) {
 496                 if (evsel->attr.type == ptr->cs_etm_pmu->type)
 497                         return perf_evsel__enable(evsel);
 498         }
 499         return -EINVAL;
 500 }
 501
 502 static u64 cs_etm_reference(struct auxtrace_record *itr __maybe_unused)
 503 {
 504         return (((u64) rand() <<  0) & 0x00000000FFFFFFFFull) |
 505                 (((u64) rand() << 32) & 0xFFFFFFFF00000000ull);
 506 }
 507
 508 static void cs_etm_recording_free(struct auxtrace_record *itr)
 509 {
 510         struct cs_etm_recording *ptr =
 511                         container_of(itr, struct cs_etm_recording, itr);
 512         free(ptr);
 513 }
 514
 515 static int cs_etm_read_finish(struct auxtrace_record *itr, int idx)
 516 {
 517         struct cs_etm_recording *ptr =
 518                         container_of(itr, struct cs_etm_recording, itr);
 519         struct perf_evsel *evsel;
 520
 521         evlist__for_each_entry(ptr->evlist, evsel) {
 522                 if (evsel->attr.type == ptr->cs_etm_pmu->type)
 523                         return perf_evlist__enable_event_idx(ptr->evlist,
 524                                                              evsel, idx);
 525         }
 526
 527         return -EINVAL;
 528 }
 529
 530 struct auxtrace_record *cs_etm_record_init(int *err)
 531 {
 532         struct perf_pmu *cs_etm_pmu;
 533         struct cs_etm_recording *ptr;
 534
 535         cs_etm_pmu = perf_pmu__find(CORESIGHT_ETM_PMU_NAME);
 536
 537         if (!cs_etm_pmu) {
 538                 *err = -EINVAL;
 539                 goto out;
 540         }
 541
 542         ptr = zalloc(sizeof(struct cs_etm_recording));
 543         if (!ptr) {
 544                 *err = -ENOMEM;
 545                 goto out;
 546         }
 547
 548         ptr->cs_etm_pmu                 = cs_etm_pmu;
 549         ptr->itr.parse_snapshot_options = cs_etm_parse_snapshot_options;
 550         ptr->itr.recording_options      = cs_etm_recording_options;
 551         ptr->itr.info_priv_size         = cs_etm_info_priv_size;
 552         ptr->itr.info_fill              = cs_etm_info_fill;
 553         ptr->itr.find_snapshot          = cs_etm_find_snapshot;
 554         ptr->itr.snapshot_start         = cs_etm_snapshot_start;
 555         ptr->itr.snapshot_finish        = cs_etm_snapshot_finish;
 556         ptr->itr.reference              = cs_etm_reference;
 557         ptr->itr.free                   = cs_etm_recording_free;
 558         ptr->itr.read_finish            = cs_etm_read_finish;
 559
 560         *err = 0;
 561         return &ptr->itr;
 562 out:
 563         return NULL;
 564 }
 565
 566 static FILE *cs_device__open_file(const char *name)
 567 {
 568         struct stat st;
 569         char path[PATH_MAX];
 570         const char *sysfs;
 571
 572         sysfs = sysfs__mountpoint();
 573         if (!sysfs)
 574                 return NULL;
 575
 576         snprintf(path, PATH_MAX,
 577                  "%s" CS_BUS_DEVICE_PATH "%s", sysfs, name);
 578
 579         if (stat(path, &st) < 0)
 580                 return NULL;
 581
 582         return fopen(path, "w");
 583
 584 }
 585
 586 static __attribute__((format(printf, 2, 3)))
 587 int cs_device__print_file(const char *name, const char *fmt, ...)
 588 {
 589         va_list args;
 590         FILE *file;
 591         int ret = -EINVAL;
 592
 593         va_start(args, fmt);
 594         file = cs_device__open_file(name);
 595         if (file) {
 596                 ret = vfprintf(file, fmt, args);
 597                 fclose(file);
 598         }
 599         va_end(args);
 600         return ret;
 601 }
 602
 603 int cs_etm_set_drv_config(struct perf_evsel_config_term *term)
 604 {
 605         int ret;
 606         char enable_sink[ENABLE_SINK_MAX];
 607
 608         snprintf(enable_sink, ENABLE_SINK_MAX, "%s/%s",
 609                  term->val.drv_cfg, "enable_sink");
 610
 611         ret = cs_device__print_file(enable_sink, "%d", 1);
 612         if (ret < 0)
 613                 return ret;
 614
 615         return 0;
 616 }