1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * intel-bts.c: Intel Processor Trace support 4 * Copyright (c) 2013-2015, Intel Corporation. 5 */ 6 7 #include <errno.h> 8 #include <linux/kernel.h> 9 #include <linux/types.h> 10 #include <linux/bitops.h> 11 #include <linux/log2.h> 12 #include <linux/zalloc.h> 13 14 #include "../../util/cpumap.h" 15 #include "../../util/event.h" 16 #include "../../util/evsel.h" 17 #include "../../util/evlist.h" 18 #include "../../util/mmap.h" 19 #include "../../util/session.h" 20 #include "../../util/pmu.h" 21 #include "../../util/debug.h" 22 #include "../../util/record.h" 23 #include "../../util/tsc.h" 24 #include "../../util/auxtrace.h" 25 #include "../../util/intel-bts.h" 26 #include <internal/lib.h> // page_size 27 28 #define KiB(x) ((x) * 1024) 29 #define MiB(x) ((x) * 1024 * 1024) 30 #define KiB_MASK(x) (KiB(x) - 1) 31 #define MiB_MASK(x) (MiB(x) - 1) 32 33 struct intel_bts_snapshot_ref { 34 void *ref_buf; 35 size_t ref_offset; 36 bool wrapped; 37 }; 38 39 struct intel_bts_recording { 40 struct auxtrace_record itr; 41 struct perf_pmu *intel_bts_pmu; 42 struct evlist *evlist; 43 bool snapshot_mode; 44 size_t snapshot_size; 45 int snapshot_ref_cnt; 46 struct intel_bts_snapshot_ref *snapshot_refs; 47 }; 48 49 struct branch { 50 u64 from; 51 u64 to; 52 u64 misc; 53 }; 54 55 static size_t 56 intel_bts_info_priv_size(struct auxtrace_record *itr __maybe_unused, 57 struct evlist *evlist __maybe_unused) 58 { 59 return INTEL_BTS_AUXTRACE_PRIV_SIZE; 60 } 61 62 static int intel_bts_info_fill(struct auxtrace_record *itr, 63 struct perf_session *session, 64 struct perf_record_auxtrace_info *auxtrace_info, 65 size_t priv_size) 66 { 67 struct intel_bts_recording *btsr = 68 container_of(itr, struct intel_bts_recording, itr); 69 struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu; 70 struct perf_event_mmap_page *pc; 71 struct perf_tsc_conversion tc = { .time_mult = 0, }; 72 bool cap_user_time_zero = false; 73 int err; 74 75 if (priv_size != INTEL_BTS_AUXTRACE_PRIV_SIZE) 76 return -EINVAL; 77 78 if (!session->evlist->core.nr_mmaps) 79 return -EINVAL; 80 81 pc = session->evlist->mmap[0].core.base; 82 if (pc) { 83 err = perf_read_tsc_conversion(pc, &tc); 84 if (err) { 85 if (err != -EOPNOTSUPP) 86 return err; 87 } else { 88 cap_user_time_zero = tc.time_mult != 0; 89 } 90 if (!cap_user_time_zero) 91 ui__warning("Intel BTS: TSC not available\n"); 92 } 93 94 auxtrace_info->type = PERF_AUXTRACE_INTEL_BTS; 95 auxtrace_info->priv[INTEL_BTS_PMU_TYPE] = intel_bts_pmu->type; 96 auxtrace_info->priv[INTEL_BTS_TIME_SHIFT] = tc.time_shift; 97 auxtrace_info->priv[INTEL_BTS_TIME_MULT] = tc.time_mult; 98 auxtrace_info->priv[INTEL_BTS_TIME_ZERO] = tc.time_zero; 99 auxtrace_info->priv[INTEL_BTS_CAP_USER_TIME_ZERO] = cap_user_time_zero; 100 auxtrace_info->priv[INTEL_BTS_SNAPSHOT_MODE] = btsr->snapshot_mode; 101 102 return 0; 103 } 104 105 static int intel_bts_recording_options(struct auxtrace_record *itr, 106 struct evlist *evlist, 107 struct record_opts *opts) 108 { 109 struct intel_bts_recording *btsr = 110 container_of(itr, struct intel_bts_recording, itr); 111 struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu; 112 struct evsel *evsel, *intel_bts_evsel = NULL; 113 const struct perf_cpu_map *cpus = evlist->core.cpus; 114 bool privileged = perf_event_paranoid_check(-1); 115 116 btsr->evlist = evlist; 117 btsr->snapshot_mode = opts->auxtrace_snapshot_mode; 118 119 evlist__for_each_entry(evlist, evsel) { 120 if (evsel->core.attr.type == intel_bts_pmu->type) { 121 if (intel_bts_evsel) { 122 pr_err("There may be only one " INTEL_BTS_PMU_NAME " event\n"); 123 return -EINVAL; 124 } 125 evsel->core.attr.freq = 0; 126 evsel->core.attr.sample_period = 1; 127 intel_bts_evsel = evsel; 128 opts->full_auxtrace = true; 129 } 130 } 131 132 if (opts->auxtrace_snapshot_mode && !opts->full_auxtrace) { 133 pr_err("Snapshot mode (-S option) requires " INTEL_BTS_PMU_NAME " PMU event (-e " INTEL_BTS_PMU_NAME ")\n"); 134 return -EINVAL; 135 } 136 137 if (!opts->full_auxtrace) 138 return 0; 139 140 if (opts->full_auxtrace && !perf_cpu_map__empty(cpus)) { 141 pr_err(INTEL_BTS_PMU_NAME " does not support per-cpu recording\n"); 142 return -EINVAL; 143 } 144 145 /* Set default sizes for snapshot mode */ 146 if (opts->auxtrace_snapshot_mode) { 147 if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) { 148 if (privileged) { 149 opts->auxtrace_mmap_pages = MiB(4) / page_size; 150 } else { 151 opts->auxtrace_mmap_pages = KiB(128) / page_size; 152 if (opts->mmap_pages == UINT_MAX) 153 opts->mmap_pages = KiB(256) / page_size; 154 } 155 } else if (!opts->auxtrace_mmap_pages && !privileged && 156 opts->mmap_pages == UINT_MAX) { 157 opts->mmap_pages = KiB(256) / page_size; 158 } 159 if (!opts->auxtrace_snapshot_size) 160 opts->auxtrace_snapshot_size = 161 opts->auxtrace_mmap_pages * (size_t)page_size; 162 if (!opts->auxtrace_mmap_pages) { 163 size_t sz = opts->auxtrace_snapshot_size; 164 165 sz = round_up(sz, page_size) / page_size; 166 opts->auxtrace_mmap_pages = roundup_pow_of_two(sz); 167 } 168 if (opts->auxtrace_snapshot_size > 169 opts->auxtrace_mmap_pages * (size_t)page_size) { 170 pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n", 171 opts->auxtrace_snapshot_size, 172 opts->auxtrace_mmap_pages * (size_t)page_size); 173 return -EINVAL; 174 } 175 if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) { 176 pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n"); 177 return -EINVAL; 178 } 179 pr_debug2("Intel BTS snapshot size: %zu\n", 180 opts->auxtrace_snapshot_size); 181 } 182 183 /* Set default sizes for full trace mode */ 184 if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) { 185 if (privileged) { 186 opts->auxtrace_mmap_pages = MiB(4) / page_size; 187 } else { 188 opts->auxtrace_mmap_pages = KiB(128) / page_size; 189 if (opts->mmap_pages == UINT_MAX) 190 opts->mmap_pages = KiB(256) / page_size; 191 } 192 } 193 194 /* Validate auxtrace_mmap_pages */ 195 if (opts->auxtrace_mmap_pages) { 196 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size; 197 size_t min_sz; 198 199 if (opts->auxtrace_snapshot_mode) 200 min_sz = KiB(4); 201 else 202 min_sz = KiB(8); 203 204 if (sz < min_sz || !is_power_of_2(sz)) { 205 pr_err("Invalid mmap size for Intel BTS: must be at least %zuKiB and a power of 2\n", 206 min_sz / 1024); 207 return -EINVAL; 208 } 209 } 210 211 if (intel_bts_evsel) { 212 /* 213 * To obtain the auxtrace buffer file descriptor, the auxtrace event 214 * must come first. 215 */ 216 perf_evlist__to_front(evlist, intel_bts_evsel); 217 /* 218 * In the case of per-cpu mmaps, we need the CPU on the 219 * AUX event. 220 */ 221 if (!perf_cpu_map__empty(cpus)) 222 perf_evsel__set_sample_bit(intel_bts_evsel, CPU); 223 } 224 225 /* Add dummy event to keep tracking */ 226 if (opts->full_auxtrace) { 227 struct evsel *tracking_evsel; 228 int err; 229 230 err = parse_events(evlist, "dummy:u", NULL); 231 if (err) 232 return err; 233 234 tracking_evsel = evlist__last(evlist); 235 236 perf_evlist__set_tracking_event(evlist, tracking_evsel); 237 238 tracking_evsel->core.attr.freq = 0; 239 tracking_evsel->core.attr.sample_period = 1; 240 } 241 242 return 0; 243 } 244 245 static int intel_bts_parse_snapshot_options(struct auxtrace_record *itr, 246 struct record_opts *opts, 247 const char *str) 248 { 249 struct intel_bts_recording *btsr = 250 container_of(itr, struct intel_bts_recording, itr); 251 unsigned long long snapshot_size = 0; 252 char *endptr; 253 254 if (str) { 255 snapshot_size = strtoull(str, &endptr, 0); 256 if (*endptr || snapshot_size > SIZE_MAX) 257 return -1; 258 } 259 260 opts->auxtrace_snapshot_mode = true; 261 opts->auxtrace_snapshot_size = snapshot_size; 262 263 btsr->snapshot_size = snapshot_size; 264 265 return 0; 266 } 267 268 static u64 intel_bts_reference(struct auxtrace_record *itr __maybe_unused) 269 { 270 return rdtsc(); 271 } 272 273 static int intel_bts_alloc_snapshot_refs(struct intel_bts_recording *btsr, 274 int idx) 275 { 276 const size_t sz = sizeof(struct intel_bts_snapshot_ref); 277 int cnt = btsr->snapshot_ref_cnt, new_cnt = cnt * 2; 278 struct intel_bts_snapshot_ref *refs; 279 280 if (!new_cnt) 281 new_cnt = 16; 282 283 while (new_cnt <= idx) 284 new_cnt *= 2; 285 286 refs = calloc(new_cnt, sz); 287 if (!refs) 288 return -ENOMEM; 289 290 memcpy(refs, btsr->snapshot_refs, cnt * sz); 291 292 btsr->snapshot_refs = refs; 293 btsr->snapshot_ref_cnt = new_cnt; 294 295 return 0; 296 } 297 298 static void intel_bts_free_snapshot_refs(struct intel_bts_recording *btsr) 299 { 300 int i; 301 302 for (i = 0; i < btsr->snapshot_ref_cnt; i++) 303 zfree(&btsr->snapshot_refs[i].ref_buf); 304 zfree(&btsr->snapshot_refs); 305 } 306 307 static void intel_bts_recording_free(struct auxtrace_record *itr) 308 { 309 struct intel_bts_recording *btsr = 310 container_of(itr, struct intel_bts_recording, itr); 311 312 intel_bts_free_snapshot_refs(btsr); 313 free(btsr); 314 } 315 316 static int intel_bts_snapshot_start(struct auxtrace_record *itr) 317 { 318 struct intel_bts_recording *btsr = 319 container_of(itr, struct intel_bts_recording, itr); 320 struct evsel *evsel; 321 322 evlist__for_each_entry(btsr->evlist, evsel) { 323 if (evsel->core.attr.type == btsr->intel_bts_pmu->type) 324 return evsel__disable(evsel); 325 } 326 return -EINVAL; 327 } 328 329 static int intel_bts_snapshot_finish(struct auxtrace_record *itr) 330 { 331 struct intel_bts_recording *btsr = 332 container_of(itr, struct intel_bts_recording, itr); 333 struct evsel *evsel; 334 335 evlist__for_each_entry(btsr->evlist, evsel) { 336 if (evsel->core.attr.type == btsr->intel_bts_pmu->type) 337 return evsel__enable(evsel); 338 } 339 return -EINVAL; 340 } 341 342 static bool intel_bts_first_wrap(u64 *data, size_t buf_size) 343 { 344 int i, a, b; 345 346 b = buf_size >> 3; 347 a = b - 512; 348 if (a < 0) 349 a = 0; 350 351 for (i = a; i < b; i++) { 352 if (data[i]) 353 return true; 354 } 355 356 return false; 357 } 358 359 static int intel_bts_find_snapshot(struct auxtrace_record *itr, int idx, 360 struct auxtrace_mmap *mm, unsigned char *data, 361 u64 *head, u64 *old) 362 { 363 struct intel_bts_recording *btsr = 364 container_of(itr, struct intel_bts_recording, itr); 365 bool wrapped; 366 int err; 367 368 pr_debug3("%s: mmap index %d old head %zu new head %zu\n", 369 __func__, idx, (size_t)*old, (size_t)*head); 370 371 if (idx >= btsr->snapshot_ref_cnt) { 372 err = intel_bts_alloc_snapshot_refs(btsr, idx); 373 if (err) 374 goto out_err; 375 } 376 377 wrapped = btsr->snapshot_refs[idx].wrapped; 378 if (!wrapped && intel_bts_first_wrap((u64 *)data, mm->len)) { 379 btsr->snapshot_refs[idx].wrapped = true; 380 wrapped = true; 381 } 382 383 /* 384 * In full trace mode 'head' continually increases. However in snapshot 385 * mode 'head' is an offset within the buffer. Here 'old' and 'head' 386 * are adjusted to match the full trace case which expects that 'old' is 387 * always less than 'head'. 388 */ 389 if (wrapped) { 390 *old = *head; 391 *head += mm->len; 392 } else { 393 if (mm->mask) 394 *old &= mm->mask; 395 else 396 *old %= mm->len; 397 if (*old > *head) 398 *head += mm->len; 399 } 400 401 pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n", 402 __func__, wrapped ? "" : "not ", (size_t)*old, (size_t)*head); 403 404 return 0; 405 406 out_err: 407 pr_err("%s: failed, error %d\n", __func__, err); 408 return err; 409 } 410 411 static int intel_bts_read_finish(struct auxtrace_record *itr, int idx) 412 { 413 struct intel_bts_recording *btsr = 414 container_of(itr, struct intel_bts_recording, itr); 415 struct evsel *evsel; 416 417 evlist__for_each_entry(btsr->evlist, evsel) { 418 if (evsel->core.attr.type == btsr->intel_bts_pmu->type) 419 return perf_evlist__enable_event_idx(btsr->evlist, 420 evsel, idx); 421 } 422 return -EINVAL; 423 } 424 425 struct auxtrace_record *intel_bts_recording_init(int *err) 426 { 427 struct perf_pmu *intel_bts_pmu = perf_pmu__find(INTEL_BTS_PMU_NAME); 428 struct intel_bts_recording *btsr; 429 430 if (!intel_bts_pmu) 431 return NULL; 432 433 if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) { 434 *err = -errno; 435 return NULL; 436 } 437 438 btsr = zalloc(sizeof(struct intel_bts_recording)); 439 if (!btsr) { 440 *err = -ENOMEM; 441 return NULL; 442 } 443 444 btsr->intel_bts_pmu = intel_bts_pmu; 445 btsr->itr.recording_options = intel_bts_recording_options; 446 btsr->itr.info_priv_size = intel_bts_info_priv_size; 447 btsr->itr.info_fill = intel_bts_info_fill; 448 btsr->itr.free = intel_bts_recording_free; 449 btsr->itr.snapshot_start = intel_bts_snapshot_start; 450 btsr->itr.snapshot_finish = intel_bts_snapshot_finish; 451 btsr->itr.find_snapshot = intel_bts_find_snapshot; 452 btsr->itr.parse_snapshot_options = intel_bts_parse_snapshot_options; 453 btsr->itr.reference = intel_bts_reference; 454 btsr->itr.read_finish = intel_bts_read_finish; 455 btsr->itr.alignment = sizeof(struct branch); 456 return &btsr->itr; 457 } 458