1 /* 2 * Performance events x86 architecture code 3 * 4 * Copyright (C) 2008 Linutronix GmbH, Thomas Gleixner <tglx@kernel.org> 5 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar 6 * Copyright (C) 2009 Jaswinder Singh Rajput 7 * Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter 8 * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra 9 * Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com> 10 * Copyright (C) 2009 Google, Inc., Stephane Eranian 11 * 12 * For licencing details see kernel-base/COPYING 13 */ 14 15 #include <linux/perf_event.h> 16 #include <linux/capability.h> 17 #include <linux/notifier.h> 18 #include <linux/hardirq.h> 19 #include <linux/kprobes.h> 20 #include <linux/export.h> 21 #include <linux/init.h> 22 #include <linux/kdebug.h> 23 #include <linux/kvm_types.h> 24 #include <linux/sched/mm.h> 25 #include <linux/sched/clock.h> 26 #include <linux/uaccess.h> 27 #include <linux/slab.h> 28 #include <linux/cpu.h> 29 #include <linux/bitops.h> 30 #include <linux/device.h> 31 #include <linux/nospec.h> 32 #include <linux/static_call.h> 33 #include <linux/kvm_types.h> 34 35 #include <asm/apic.h> 36 #include <asm/stacktrace.h> 37 #include <asm/msr.h> 38 #include <asm/nmi.h> 39 #include <asm/smp.h> 40 #include <asm/alternative.h> 41 #include <asm/mmu_context.h> 42 #include <asm/tlbflush.h> 43 #include <asm/timer.h> 44 #include <asm/desc.h> 45 #include <asm/ldt.h> 46 #include <asm/unwind.h> 47 #include <asm/uprobes.h> 48 #include <asm/ibt.h> 49 50 #include "perf_event.h" 51 52 struct x86_pmu x86_pmu __read_mostly; 53 static struct pmu pmu; 54 55 DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = { 56 .enabled = 1, 57 .pmu = &pmu, 58 }; 59 60 static DEFINE_PER_CPU(bool, guest_lvtpc_loaded); 61 62 DEFINE_STATIC_KEY_FALSE(rdpmc_never_available_key); 63 DEFINE_STATIC_KEY_FALSE(rdpmc_always_available_key); 64 DEFINE_STATIC_KEY_FALSE(perf_is_hybrid); 65 66 /* 67 * This here uses DEFINE_STATIC_CALL_NULL() to get a static_call defined 68 * from just a typename, as opposed to an actual function. 69 */ 70 DEFINE_STATIC_CALL_NULL(x86_pmu_handle_irq, *x86_pmu.handle_irq); 71 DEFINE_STATIC_CALL_NULL(x86_pmu_disable_all, *x86_pmu.disable_all); 72 DEFINE_STATIC_CALL_NULL(x86_pmu_enable_all, *x86_pmu.enable_all); 73 DEFINE_STATIC_CALL_NULL(x86_pmu_enable, *x86_pmu.enable); 74 DEFINE_STATIC_CALL_NULL(x86_pmu_disable, *x86_pmu.disable); 75 76 DEFINE_STATIC_CALL_NULL(x86_pmu_assign, *x86_pmu.assign); 77 78 DEFINE_STATIC_CALL_NULL(x86_pmu_add, *x86_pmu.add); 79 DEFINE_STATIC_CALL_NULL(x86_pmu_del, *x86_pmu.del); 80 DEFINE_STATIC_CALL_NULL(x86_pmu_read, *x86_pmu.read); 81 82 DEFINE_STATIC_CALL_NULL(x86_pmu_set_period, *x86_pmu.set_period); 83 DEFINE_STATIC_CALL_NULL(x86_pmu_update, *x86_pmu.update); 84 DEFINE_STATIC_CALL_NULL(x86_pmu_limit_period, *x86_pmu.limit_period); 85 86 DEFINE_STATIC_CALL_NULL(x86_pmu_schedule_events, *x86_pmu.schedule_events); 87 DEFINE_STATIC_CALL_NULL(x86_pmu_get_event_constraints, *x86_pmu.get_event_constraints); 88 DEFINE_STATIC_CALL_NULL(x86_pmu_put_event_constraints, *x86_pmu.put_event_constraints); 89 90 DEFINE_STATIC_CALL_NULL(x86_pmu_start_scheduling, *x86_pmu.start_scheduling); 91 DEFINE_STATIC_CALL_NULL(x86_pmu_commit_scheduling, *x86_pmu.commit_scheduling); 92 DEFINE_STATIC_CALL_NULL(x86_pmu_stop_scheduling, *x86_pmu.stop_scheduling); 93 94 DEFINE_STATIC_CALL_NULL(x86_pmu_sched_task, *x86_pmu.sched_task); 95 96 DEFINE_STATIC_CALL_NULL(x86_pmu_drain_pebs, *x86_pmu.drain_pebs); 97 DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_aliases, *x86_pmu.pebs_aliases); 98 99 DEFINE_STATIC_CALL_NULL(x86_pmu_filter, *x86_pmu.filter); 100 101 DEFINE_STATIC_CALL_NULL(x86_pmu_late_setup, *x86_pmu.late_setup); 102 103 DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_enable, *x86_pmu.pebs_enable); 104 DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_disable, *x86_pmu.pebs_disable); 105 DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_enable_all, *x86_pmu.pebs_enable_all); 106 DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_disable_all, *x86_pmu.pebs_disable_all); 107 108 /* 109 * This one is magic, it will get called even when PMU init fails (because 110 * there is no PMU), in which case it should simply return NULL. 111 */ 112 DEFINE_STATIC_CALL_RET0(x86_pmu_guest_get_msrs, *x86_pmu.guest_get_msrs); 113 114 u64 __read_mostly hw_cache_event_ids 115 [PERF_COUNT_HW_CACHE_MAX] 116 [PERF_COUNT_HW_CACHE_OP_MAX] 117 [PERF_COUNT_HW_CACHE_RESULT_MAX]; 118 u64 __read_mostly hw_cache_extra_regs 119 [PERF_COUNT_HW_CACHE_MAX] 120 [PERF_COUNT_HW_CACHE_OP_MAX] 121 [PERF_COUNT_HW_CACHE_RESULT_MAX]; 122 123 /* 124 * Propagate event elapsed time into the generic event. 125 * Can only be executed on the CPU where the event is active. 126 * Returns the delta events processed. 127 */ 128 u64 x86_perf_event_update(struct perf_event *event) 129 { 130 struct hw_perf_event *hwc = &event->hw; 131 int shift = 64 - x86_pmu.cntval_bits; 132 u64 prev_raw_count, new_raw_count; 133 u64 delta; 134 135 if (unlikely(!hwc->event_base)) 136 return 0; 137 138 /* 139 * Careful: an NMI might modify the previous event value. 140 * 141 * Our tactic to handle this is to first atomically read and 142 * exchange a new raw count - then add that new-prev delta 143 * count to the generic event atomically: 144 */ 145 prev_raw_count = local64_read(&hwc->prev_count); 146 do { 147 new_raw_count = rdpmc(hwc->event_base_rdpmc); 148 } while (!local64_try_cmpxchg(&hwc->prev_count, 149 &prev_raw_count, new_raw_count)); 150 151 /* 152 * Now we have the new raw value and have updated the prev 153 * timestamp already. We can now calculate the elapsed delta 154 * (event-)time and add that to the generic event. 155 * 156 * Careful, not all hw sign-extends above the physical width 157 * of the count. 158 */ 159 delta = (new_raw_count << shift) - (prev_raw_count << shift); 160 delta >>= shift; 161 162 local64_add(delta, &event->count); 163 local64_sub(delta, &hwc->period_left); 164 165 return new_raw_count; 166 } 167 168 /* 169 * Find and validate any extra registers to set up. 170 */ 171 static int x86_pmu_extra_regs(u64 config, struct perf_event *event) 172 { 173 struct extra_reg *extra_regs = hybrid(event->pmu, extra_regs); 174 struct hw_perf_event_extra *reg; 175 struct extra_reg *er; 176 177 reg = &event->hw.extra_reg; 178 179 if (!extra_regs) 180 return 0; 181 182 for (er = extra_regs; er->msr; er++) { 183 if (er->event != (config & er->config_mask)) 184 continue; 185 if (event->attr.config1 & ~er->valid_mask) 186 return -EINVAL; 187 /* Check if the extra msrs can be safely accessed*/ 188 if (!er->extra_msr_access) 189 return -ENXIO; 190 191 reg->idx = er->idx; 192 reg->config = event->attr.config1; 193 reg->reg = er->msr; 194 break; 195 } 196 return 0; 197 } 198 199 static atomic_t active_events; 200 static atomic_t pmc_refcount; 201 static DEFINE_MUTEX(pmc_reserve_mutex); 202 203 #ifdef CONFIG_X86_LOCAL_APIC 204 205 static inline u64 get_possible_counter_mask(void) 206 { 207 u64 cntr_mask = x86_pmu.cntr_mask64; 208 int i; 209 210 if (!is_hybrid()) 211 return cntr_mask; 212 213 for (i = 0; i < x86_pmu.num_hybrid_pmus; i++) 214 cntr_mask |= x86_pmu.hybrid_pmu[i].cntr_mask64; 215 216 return cntr_mask; 217 } 218 219 static bool reserve_pmc_hardware(void) 220 { 221 u64 cntr_mask = get_possible_counter_mask(); 222 int i, end; 223 224 for_each_set_bit(i, (unsigned long *)&cntr_mask, X86_PMC_IDX_MAX) { 225 if (!reserve_perfctr_nmi(x86_pmu_event_addr(i))) 226 goto perfctr_fail; 227 } 228 229 for_each_set_bit(i, (unsigned long *)&cntr_mask, X86_PMC_IDX_MAX) { 230 if (!reserve_evntsel_nmi(x86_pmu_config_addr(i))) 231 goto eventsel_fail; 232 } 233 234 return true; 235 236 eventsel_fail: 237 end = i; 238 for_each_set_bit(i, (unsigned long *)&cntr_mask, end) 239 release_evntsel_nmi(x86_pmu_config_addr(i)); 240 i = X86_PMC_IDX_MAX; 241 242 perfctr_fail: 243 end = i; 244 for_each_set_bit(i, (unsigned long *)&cntr_mask, end) 245 release_perfctr_nmi(x86_pmu_event_addr(i)); 246 247 return false; 248 } 249 250 static void release_pmc_hardware(void) 251 { 252 u64 cntr_mask = get_possible_counter_mask(); 253 int i; 254 255 for_each_set_bit(i, (unsigned long *)&cntr_mask, X86_PMC_IDX_MAX) { 256 release_perfctr_nmi(x86_pmu_event_addr(i)); 257 release_evntsel_nmi(x86_pmu_config_addr(i)); 258 } 259 } 260 261 #else 262 263 static bool reserve_pmc_hardware(void) { return true; } 264 static void release_pmc_hardware(void) {} 265 266 #endif 267 268 bool check_hw_exists(struct pmu *pmu, unsigned long *cntr_mask, 269 unsigned long *fixed_cntr_mask) 270 { 271 u64 val, val_fail = -1, val_new= ~0; 272 int i, reg, reg_fail = -1, ret = 0; 273 int bios_fail = 0; 274 int reg_safe = -1; 275 276 /* 277 * Check to see if the BIOS enabled any of the counters, if so 278 * complain and bail. 279 */ 280 for_each_set_bit(i, cntr_mask, X86_PMC_IDX_MAX) { 281 reg = x86_pmu_config_addr(i); 282 ret = rdmsrq_safe(reg, &val); 283 if (ret) 284 goto msr_fail; 285 if (val & ARCH_PERFMON_EVENTSEL_ENABLE) { 286 bios_fail = 1; 287 val_fail = val; 288 reg_fail = reg; 289 } else { 290 reg_safe = i; 291 } 292 } 293 294 if (*(u64 *)fixed_cntr_mask) { 295 reg = MSR_ARCH_PERFMON_FIXED_CTR_CTRL; 296 ret = rdmsrq_safe(reg, &val); 297 if (ret) 298 goto msr_fail; 299 for_each_set_bit(i, fixed_cntr_mask, X86_PMC_IDX_MAX) { 300 if (fixed_counter_disabled(i, pmu)) 301 continue; 302 if (val & (0x03ULL << i*4)) { 303 bios_fail = 1; 304 val_fail = val; 305 reg_fail = reg; 306 } 307 } 308 } 309 310 /* 311 * If all the counters are enabled, the below test will always 312 * fail. The tools will also become useless in this scenario. 313 * Just fail and disable the hardware counters. 314 */ 315 316 if (reg_safe == -1) { 317 reg = reg_safe; 318 goto msr_fail; 319 } 320 321 /* 322 * Read the current value, change it and read it back to see if it 323 * matches, this is needed to detect certain hardware emulators 324 * (qemu/kvm) that don't trap on the MSR access and always return 0s. 325 */ 326 reg = x86_pmu_event_addr(reg_safe); 327 if (rdmsrq_safe(reg, &val)) 328 goto msr_fail; 329 val ^= 0xffffUL; 330 ret = wrmsrq_safe(reg, val); 331 ret |= rdmsrq_safe(reg, &val_new); 332 if (ret || val != val_new) 333 goto msr_fail; 334 335 /* 336 * We still allow the PMU driver to operate: 337 */ 338 if (bios_fail) { 339 pr_cont("Broken BIOS detected, complain to your hardware vendor.\n"); 340 pr_err(FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n", 341 reg_fail, val_fail); 342 } 343 344 return true; 345 346 msr_fail: 347 if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) { 348 pr_cont("PMU not available due to virtualization, using software events only.\n"); 349 } else { 350 pr_cont("Broken PMU hardware detected, using software events only.\n"); 351 pr_err("Failed to access perfctr msr (MSR %x is %Lx)\n", 352 reg, val_new); 353 } 354 355 return false; 356 } 357 358 static void hw_perf_event_destroy(struct perf_event *event) 359 { 360 x86_release_hardware(); 361 atomic_dec(&active_events); 362 } 363 364 void hw_perf_lbr_event_destroy(struct perf_event *event) 365 { 366 hw_perf_event_destroy(event); 367 368 /* undo the lbr/bts event accounting */ 369 x86_del_exclusive(x86_lbr_exclusive_lbr); 370 } 371 372 static inline int x86_pmu_initialized(void) 373 { 374 return x86_pmu.handle_irq != NULL; 375 } 376 377 static inline int 378 set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event *event) 379 { 380 struct perf_event_attr *attr = &event->attr; 381 unsigned int cache_type, cache_op, cache_result; 382 u64 config, val; 383 384 config = attr->config; 385 386 cache_type = (config >> 0) & 0xff; 387 if (cache_type >= PERF_COUNT_HW_CACHE_MAX) 388 return -EINVAL; 389 cache_type = array_index_nospec(cache_type, PERF_COUNT_HW_CACHE_MAX); 390 391 cache_op = (config >> 8) & 0xff; 392 if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX) 393 return -EINVAL; 394 cache_op = array_index_nospec(cache_op, PERF_COUNT_HW_CACHE_OP_MAX); 395 396 cache_result = (config >> 16) & 0xff; 397 if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX) 398 return -EINVAL; 399 cache_result = array_index_nospec(cache_result, PERF_COUNT_HW_CACHE_RESULT_MAX); 400 401 val = hybrid_var(event->pmu, hw_cache_event_ids)[cache_type][cache_op][cache_result]; 402 if (val == 0) 403 return -ENOENT; 404 405 if (val == -1) 406 return -EINVAL; 407 408 hwc->config |= val; 409 attr->config1 = hybrid_var(event->pmu, hw_cache_extra_regs)[cache_type][cache_op][cache_result]; 410 return x86_pmu_extra_regs(val, event); 411 } 412 413 int x86_reserve_hardware(void) 414 { 415 int err = 0; 416 417 if (!atomic_inc_not_zero(&pmc_refcount)) { 418 mutex_lock(&pmc_reserve_mutex); 419 if (atomic_read(&pmc_refcount) == 0) { 420 if (!reserve_pmc_hardware()) { 421 err = -EBUSY; 422 } else { 423 reserve_ds_buffers(); 424 reserve_lbr_buffers(); 425 } 426 } 427 if (!err) 428 atomic_inc(&pmc_refcount); 429 mutex_unlock(&pmc_reserve_mutex); 430 } 431 432 return err; 433 } 434 435 void x86_release_hardware(void) 436 { 437 if (atomic_dec_and_mutex_lock(&pmc_refcount, &pmc_reserve_mutex)) { 438 release_pmc_hardware(); 439 release_ds_buffers(); 440 release_lbr_buffers(); 441 mutex_unlock(&pmc_reserve_mutex); 442 } 443 } 444 445 /* 446 * Check if we can create event of a certain type (that no conflicting events 447 * are present). 448 */ 449 int x86_add_exclusive(unsigned int what) 450 { 451 int i; 452 453 /* 454 * When lbr_pt_coexist we allow PT to coexist with either LBR or BTS. 455 * LBR and BTS are still mutually exclusive. 456 */ 457 if (x86_pmu.lbr_pt_coexist && what == x86_lbr_exclusive_pt) 458 goto out; 459 460 if (!atomic_inc_not_zero(&x86_pmu.lbr_exclusive[what])) { 461 mutex_lock(&pmc_reserve_mutex); 462 for (i = 0; i < ARRAY_SIZE(x86_pmu.lbr_exclusive); i++) { 463 if (i != what && atomic_read(&x86_pmu.lbr_exclusive[i])) 464 goto fail_unlock; 465 } 466 atomic_inc(&x86_pmu.lbr_exclusive[what]); 467 mutex_unlock(&pmc_reserve_mutex); 468 } 469 470 out: 471 atomic_inc(&active_events); 472 return 0; 473 474 fail_unlock: 475 mutex_unlock(&pmc_reserve_mutex); 476 return -EBUSY; 477 } 478 479 void x86_del_exclusive(unsigned int what) 480 { 481 atomic_dec(&active_events); 482 483 /* 484 * See the comment in x86_add_exclusive(). 485 */ 486 if (x86_pmu.lbr_pt_coexist && what == x86_lbr_exclusive_pt) 487 return; 488 489 atomic_dec(&x86_pmu.lbr_exclusive[what]); 490 } 491 492 int x86_setup_perfctr(struct perf_event *event) 493 { 494 struct perf_event_attr *attr = &event->attr; 495 struct hw_perf_event *hwc = &event->hw; 496 u64 config; 497 498 if (!is_sampling_event(event)) { 499 hwc->sample_period = x86_pmu.max_period; 500 hwc->last_period = hwc->sample_period; 501 local64_set(&hwc->period_left, hwc->sample_period); 502 } 503 504 if (attr->type == event->pmu->type) 505 return x86_pmu_extra_regs(event->attr.config, event); 506 507 if (attr->type == PERF_TYPE_HW_CACHE) 508 return set_ext_hw_attr(hwc, event); 509 510 if (attr->config >= x86_pmu.max_events) 511 return -EINVAL; 512 513 attr->config = array_index_nospec((unsigned long)attr->config, x86_pmu.max_events); 514 515 /* 516 * The generic map: 517 */ 518 config = x86_pmu.event_map(attr->config); 519 520 if (config == 0) 521 return -ENOENT; 522 523 if (config == -1LL) 524 return -EINVAL; 525 526 hwc->config |= config; 527 528 return 0; 529 } 530 531 /* 532 * check that branch_sample_type is compatible with 533 * settings needed for precise_ip > 1 which implies 534 * using the LBR to capture ALL taken branches at the 535 * priv levels of the measurement 536 */ 537 static inline int precise_br_compat(struct perf_event *event) 538 { 539 u64 m = event->attr.branch_sample_type; 540 u64 b = 0; 541 542 /* must capture all branches */ 543 if (!(m & PERF_SAMPLE_BRANCH_ANY)) 544 return 0; 545 546 m &= PERF_SAMPLE_BRANCH_KERNEL | PERF_SAMPLE_BRANCH_USER; 547 548 if (!event->attr.exclude_user) 549 b |= PERF_SAMPLE_BRANCH_USER; 550 551 if (!event->attr.exclude_kernel) 552 b |= PERF_SAMPLE_BRANCH_KERNEL; 553 554 /* 555 * ignore PERF_SAMPLE_BRANCH_HV, not supported on x86 556 */ 557 558 return m == b; 559 } 560 561 int x86_pmu_max_precise(struct pmu *pmu) 562 { 563 int precise = 0; 564 565 if (x86_pmu.pebs_active && !x86_pmu.pebs_broken) { 566 /* arch PEBS */ 567 if (x86_pmu.arch_pebs) { 568 precise = 2; 569 if (hybrid(pmu, arch_pebs_cap).pdists) 570 precise++; 571 572 return precise; 573 } 574 575 /* legacy PEBS - support for constant skid */ 576 precise++; 577 /* Support for IP fixup */ 578 if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2) 579 precise++; 580 581 if (x86_pmu.pebs_prec_dist) 582 precise++; 583 } 584 585 return precise; 586 } 587 588 int x86_pmu_hw_config(struct perf_event *event) 589 { 590 if (event->attr.precise_ip) { 591 int precise = x86_pmu_max_precise(event->pmu); 592 593 if (event->attr.precise_ip > precise) 594 return -EOPNOTSUPP; 595 596 /* There's no sense in having PEBS for non sampling events: */ 597 if (!is_sampling_event(event)) 598 return -EINVAL; 599 } 600 /* 601 * check that PEBS LBR correction does not conflict with 602 * whatever the user is asking with attr->branch_sample_type 603 */ 604 if (event->attr.precise_ip > 1 && x86_pmu.intel_cap.pebs_format < 2) { 605 u64 *br_type = &event->attr.branch_sample_type; 606 607 if (has_branch_stack(event)) { 608 if (!precise_br_compat(event)) 609 return -EOPNOTSUPP; 610 611 /* branch_sample_type is compatible */ 612 613 } else { 614 /* 615 * user did not specify branch_sample_type 616 * 617 * For PEBS fixups, we capture all 618 * the branches at the priv level of the 619 * event. 620 */ 621 *br_type = PERF_SAMPLE_BRANCH_ANY; 622 623 if (!event->attr.exclude_user) 624 *br_type |= PERF_SAMPLE_BRANCH_USER; 625 626 if (!event->attr.exclude_kernel) 627 *br_type |= PERF_SAMPLE_BRANCH_KERNEL; 628 } 629 } 630 631 if (branch_sample_call_stack(event)) 632 event->attach_state |= PERF_ATTACH_TASK_DATA; 633 634 /* 635 * Generate PMC IRQs: 636 * (keep 'enabled' bit clear for now) 637 */ 638 event->hw.config = ARCH_PERFMON_EVENTSEL_INT; 639 640 /* 641 * Count user and OS events unless requested not to 642 */ 643 if (!event->attr.exclude_user) 644 event->hw.config |= ARCH_PERFMON_EVENTSEL_USR; 645 if (!event->attr.exclude_kernel) 646 event->hw.config |= ARCH_PERFMON_EVENTSEL_OS; 647 648 if (event->attr.type == event->pmu->type) 649 event->hw.config |= x86_pmu_get_event_config(event); 650 651 if (is_sampling_event(event) && !event->attr.freq && x86_pmu.limit_period) { 652 s64 left = event->attr.sample_period; 653 x86_pmu.limit_period(event, &left); 654 if (left > event->attr.sample_period) 655 return -EINVAL; 656 } 657 658 /* sample_regs_user never support XMM registers */ 659 if (unlikely(event->attr.sample_regs_user & PERF_REG_EXTENDED_MASK)) 660 return -EINVAL; 661 /* 662 * Besides the general purpose registers, XMM registers may 663 * be collected in PEBS on some platforms, e.g. Icelake 664 */ 665 if (unlikely(event->attr.sample_regs_intr & PERF_REG_EXTENDED_MASK)) { 666 if (!(event->pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS)) 667 return -EINVAL; 668 669 if (!event->attr.precise_ip) 670 return -EINVAL; 671 } 672 673 return x86_setup_perfctr(event); 674 } 675 676 /* 677 * Setup the hardware configuration for a given attr_type 678 */ 679 static int __x86_pmu_event_init(struct perf_event *event) 680 { 681 int err; 682 683 if (!x86_pmu_initialized()) 684 return -ENODEV; 685 686 err = x86_reserve_hardware(); 687 if (err) 688 return err; 689 690 atomic_inc(&active_events); 691 event->destroy = hw_perf_event_destroy; 692 693 event->hw.idx = -1; 694 event->hw.last_cpu = -1; 695 event->hw.last_tag = ~0ULL; 696 event->hw.dyn_constraint = ~0ULL; 697 698 /* mark unused */ 699 event->hw.extra_reg.idx = EXTRA_REG_NONE; 700 event->hw.branch_reg.idx = EXTRA_REG_NONE; 701 702 return x86_pmu.hw_config(event); 703 } 704 705 void x86_pmu_disable_all(void) 706 { 707 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); 708 int idx; 709 710 for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) { 711 struct hw_perf_event *hwc = &cpuc->events[idx]->hw; 712 u64 val; 713 714 if (!test_bit(idx, cpuc->active_mask)) 715 continue; 716 rdmsrq(x86_pmu_config_addr(idx), val); 717 if (!(val & ARCH_PERFMON_EVENTSEL_ENABLE)) 718 continue; 719 val &= ~ARCH_PERFMON_EVENTSEL_ENABLE; 720 wrmsrq(x86_pmu_config_addr(idx), val); 721 if (is_counter_pair(hwc)) 722 wrmsrq(x86_pmu_config_addr(idx + 1), 0); 723 } 724 } 725 726 struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr, void *data) 727 { 728 return static_call(x86_pmu_guest_get_msrs)(nr, data); 729 } 730 EXPORT_SYMBOL_FOR_KVM(perf_guest_get_msrs); 731 732 /* 733 * There may be PMI landing after enabled=0. The PMI hitting could be before or 734 * after disable_all. 735 * 736 * If PMI hits before disable_all, the PMU will be disabled in the NMI handler. 737 * It will not be re-enabled in the NMI handler again, because enabled=0. After 738 * handling the NMI, disable_all will be called, which will not change the 739 * state either. If PMI hits after disable_all, the PMU is already disabled 740 * before entering NMI handler. The NMI handler will not change the state 741 * either. 742 * 743 * So either situation is harmless. 744 */ 745 static void x86_pmu_disable(struct pmu *pmu) 746 { 747 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); 748 749 if (!x86_pmu_initialized()) 750 return; 751 752 if (!cpuc->enabled) 753 return; 754 755 cpuc->n_added = 0; 756 cpuc->enabled = 0; 757 barrier(); 758 759 static_call(x86_pmu_disable_all)(); 760 } 761 762 void x86_pmu_enable_all(int added) 763 { 764 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); 765 int idx; 766 767 for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) { 768 struct hw_perf_event *hwc = &cpuc->events[idx]->hw; 769 770 if (!test_bit(idx, cpuc->active_mask)) 771 continue; 772 773 __x86_pmu_enable_event(hwc, ARCH_PERFMON_EVENTSEL_ENABLE); 774 } 775 } 776 777 int is_x86_event(struct perf_event *event) 778 { 779 /* 780 * For a non-hybrid platforms, the type of X86 pmu is 781 * always PERF_TYPE_RAW. 782 * For a hybrid platform, the PERF_PMU_CAP_EXTENDED_HW_TYPE 783 * is a unique capability for the X86 PMU. 784 * Use them to detect a X86 event. 785 */ 786 if (event->pmu->type == PERF_TYPE_RAW || 787 event->pmu->capabilities & PERF_PMU_CAP_EXTENDED_HW_TYPE) 788 return true; 789 790 return false; 791 } 792 793 struct pmu *x86_get_pmu(unsigned int cpu) 794 { 795 struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu); 796 797 /* 798 * All CPUs of the hybrid type have been offline. 799 * The x86_get_pmu() should not be invoked. 800 */ 801 if (WARN_ON_ONCE(!cpuc->pmu)) 802 return &pmu; 803 804 return cpuc->pmu; 805 } 806 /* 807 * Event scheduler state: 808 * 809 * Assign events iterating over all events and counters, beginning 810 * with events with least weights first. Keep the current iterator 811 * state in struct sched_state. 812 */ 813 struct sched_state { 814 int weight; 815 int event; /* event index */ 816 int counter; /* counter index */ 817 int unassigned; /* number of events to be assigned left */ 818 int nr_gp; /* number of GP counters used */ 819 u64 used; 820 }; 821 822 /* Total max is X86_PMC_IDX_MAX, but we are O(n!) limited */ 823 #define SCHED_STATES_MAX 2 824 825 struct perf_sched { 826 int max_weight; 827 int max_events; 828 int max_gp; 829 int saved_states; 830 struct event_constraint **constraints; 831 struct sched_state state; 832 struct sched_state saved[SCHED_STATES_MAX]; 833 }; 834 835 /* 836 * Initialize iterator that runs through all events and counters. 837 */ 838 static void perf_sched_init(struct perf_sched *sched, struct event_constraint **constraints, 839 int num, int wmin, int wmax, int gpmax) 840 { 841 int idx; 842 843 memset(sched, 0, sizeof(*sched)); 844 sched->max_events = num; 845 sched->max_weight = wmax; 846 sched->max_gp = gpmax; 847 sched->constraints = constraints; 848 849 for (idx = 0; idx < num; idx++) { 850 if (constraints[idx]->weight == wmin) 851 break; 852 } 853 854 sched->state.event = idx; /* start with min weight */ 855 sched->state.weight = wmin; 856 sched->state.unassigned = num; 857 } 858 859 static void perf_sched_save_state(struct perf_sched *sched) 860 { 861 if (WARN_ON_ONCE(sched->saved_states >= SCHED_STATES_MAX)) 862 return; 863 864 sched->saved[sched->saved_states] = sched->state; 865 sched->saved_states++; 866 } 867 868 static bool perf_sched_restore_state(struct perf_sched *sched) 869 { 870 if (!sched->saved_states) 871 return false; 872 873 sched->saved_states--; 874 sched->state = sched->saved[sched->saved_states]; 875 876 /* this assignment didn't work out */ 877 /* XXX broken vs EVENT_PAIR */ 878 sched->state.used &= ~BIT_ULL(sched->state.counter); 879 880 /* try the next one */ 881 sched->state.counter++; 882 883 return true; 884 } 885 886 /* 887 * Select a counter for the current event to schedule. Return true on 888 * success. 889 */ 890 static bool __perf_sched_find_counter(struct perf_sched *sched) 891 { 892 struct event_constraint *c; 893 int idx; 894 895 if (!sched->state.unassigned) 896 return false; 897 898 if (sched->state.event >= sched->max_events) 899 return false; 900 901 c = sched->constraints[sched->state.event]; 902 /* Prefer fixed purpose counters */ 903 if (c->idxmsk64 & (~0ULL << INTEL_PMC_IDX_FIXED)) { 904 idx = INTEL_PMC_IDX_FIXED; 905 for_each_set_bit_from(idx, c->idxmsk, X86_PMC_IDX_MAX) { 906 u64 mask = BIT_ULL(idx); 907 908 if (sched->state.used & mask) 909 continue; 910 911 sched->state.used |= mask; 912 goto done; 913 } 914 } 915 916 /* Grab the first unused counter starting with idx */ 917 idx = sched->state.counter; 918 for_each_set_bit_from(idx, c->idxmsk, INTEL_PMC_IDX_FIXED) { 919 u64 mask = BIT_ULL(idx); 920 921 if (c->flags & PERF_X86_EVENT_PAIR) 922 mask |= mask << 1; 923 924 if (sched->state.used & mask) 925 continue; 926 927 if (sched->state.nr_gp++ >= sched->max_gp) 928 return false; 929 930 sched->state.used |= mask; 931 goto done; 932 } 933 934 return false; 935 936 done: 937 sched->state.counter = idx; 938 939 if (c->overlap) 940 perf_sched_save_state(sched); 941 942 return true; 943 } 944 945 static bool perf_sched_find_counter(struct perf_sched *sched) 946 { 947 while (!__perf_sched_find_counter(sched)) { 948 if (!perf_sched_restore_state(sched)) 949 return false; 950 } 951 952 return true; 953 } 954 955 /* 956 * Go through all unassigned events and find the next one to schedule. 957 * Take events with the least weight first. Return true on success. 958 */ 959 static bool perf_sched_next_event(struct perf_sched *sched) 960 { 961 struct event_constraint *c; 962 963 if (!sched->state.unassigned || !--sched->state.unassigned) 964 return false; 965 966 do { 967 /* next event */ 968 sched->state.event++; 969 if (sched->state.event >= sched->max_events) { 970 /* next weight */ 971 sched->state.event = 0; 972 sched->state.weight++; 973 if (sched->state.weight > sched->max_weight) 974 return false; 975 } 976 c = sched->constraints[sched->state.event]; 977 } while (c->weight != sched->state.weight); 978 979 sched->state.counter = 0; /* start with first counter */ 980 981 return true; 982 } 983 984 /* 985 * Assign a counter for each event. 986 */ 987 int perf_assign_events(struct event_constraint **constraints, int n, 988 int wmin, int wmax, int gpmax, int *assign) 989 { 990 struct perf_sched sched; 991 992 perf_sched_init(&sched, constraints, n, wmin, wmax, gpmax); 993 994 do { 995 if (!perf_sched_find_counter(&sched)) 996 break; /* failed */ 997 if (assign) 998 assign[sched.state.event] = sched.state.counter; 999 } while (perf_sched_next_event(&sched)); 1000 1001 return sched.state.unassigned; 1002 } 1003 EXPORT_SYMBOL_GPL(perf_assign_events); 1004 1005 int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign) 1006 { 1007 struct event_constraint *c; 1008 struct perf_event *e; 1009 int n0, i, wmin, wmax, unsched = 0; 1010 struct hw_perf_event *hwc; 1011 u64 used_mask = 0; 1012 1013 /* 1014 * Compute the number of events already present; see x86_pmu_add(), 1015 * validate_group() and x86_pmu_commit_txn(). For the former two 1016 * cpuc->n_events hasn't been updated yet, while for the latter 1017 * cpuc->n_txn contains the number of events added in the current 1018 * transaction. 1019 */ 1020 n0 = cpuc->n_events; 1021 if (cpuc->txn_flags & PERF_PMU_TXN_ADD) 1022 n0 -= cpuc->n_txn; 1023 1024 static_call_cond(x86_pmu_start_scheduling)(cpuc); 1025 1026 for (i = 0, wmin = X86_PMC_IDX_MAX, wmax = 0; i < n; i++) { 1027 c = cpuc->event_constraint[i]; 1028 1029 /* 1030 * Previously scheduled events should have a cached constraint, 1031 * while new events should not have one. 1032 */ 1033 WARN_ON_ONCE((c && i >= n0) || (!c && i < n0)); 1034 1035 /* 1036 * Request constraints for new events; or for those events that 1037 * have a dynamic constraint -- for those the constraint can 1038 * change due to external factors (sibling state, allow_tfa). 1039 */ 1040 if (!c || (c->flags & PERF_X86_EVENT_DYNAMIC)) { 1041 c = static_call(x86_pmu_get_event_constraints)(cpuc, i, cpuc->event_list[i]); 1042 cpuc->event_constraint[i] = c; 1043 } 1044 1045 wmin = min(wmin, c->weight); 1046 wmax = max(wmax, c->weight); 1047 } 1048 1049 /* 1050 * fastpath, try to reuse previous register 1051 */ 1052 for (i = 0; i < n; i++) { 1053 u64 mask; 1054 1055 hwc = &cpuc->event_list[i]->hw; 1056 c = cpuc->event_constraint[i]; 1057 1058 /* never assigned */ 1059 if (hwc->idx == -1) 1060 break; 1061 1062 /* constraint still honored */ 1063 if (!test_bit(hwc->idx, c->idxmsk)) 1064 break; 1065 1066 mask = BIT_ULL(hwc->idx); 1067 if (is_counter_pair(hwc)) 1068 mask |= mask << 1; 1069 1070 /* not already used */ 1071 if (used_mask & mask) 1072 break; 1073 1074 used_mask |= mask; 1075 1076 if (assign) 1077 assign[i] = hwc->idx; 1078 } 1079 1080 /* slow path */ 1081 if (i != n) { 1082 int gpmax = x86_pmu_max_num_counters(cpuc->pmu); 1083 1084 /* 1085 * Do not allow scheduling of more than half the available 1086 * generic counters. 1087 * 1088 * This helps avoid counter starvation of sibling thread by 1089 * ensuring at most half the counters cannot be in exclusive 1090 * mode. There is no designated counters for the limits. Any 1091 * N/2 counters can be used. This helps with events with 1092 * specific counter constraints. 1093 */ 1094 if (is_ht_workaround_enabled() && !cpuc->is_fake && 1095 READ_ONCE(cpuc->excl_cntrs->exclusive_present)) 1096 gpmax /= 2; 1097 1098 /* 1099 * Reduce the amount of available counters to allow fitting 1100 * the extra Merge events needed by large increment events. 1101 */ 1102 if (x86_pmu.flags & PMU_FL_PAIR) { 1103 gpmax -= cpuc->n_pair; 1104 WARN_ON(gpmax <= 0); 1105 } 1106 1107 unsched = perf_assign_events(cpuc->event_constraint, n, wmin, 1108 wmax, gpmax, assign); 1109 } 1110 1111 /* 1112 * In case of success (unsched = 0), mark events as committed, 1113 * so we do not put_constraint() in case new events are added 1114 * and fail to be scheduled 1115 * 1116 * We invoke the lower level commit callback to lock the resource 1117 * 1118 * We do not need to do all of this in case we are called to 1119 * validate an event group (assign == NULL) 1120 */ 1121 if (!unsched && assign) { 1122 for (i = 0; i < n; i++) 1123 static_call_cond(x86_pmu_commit_scheduling)(cpuc, i, assign[i]); 1124 } else { 1125 for (i = n0; i < n; i++) { 1126 e = cpuc->event_list[i]; 1127 1128 /* 1129 * release events that failed scheduling 1130 */ 1131 static_call_cond(x86_pmu_put_event_constraints)(cpuc, e); 1132 1133 cpuc->event_constraint[i] = NULL; 1134 } 1135 } 1136 1137 static_call_cond(x86_pmu_stop_scheduling)(cpuc); 1138 1139 return unsched ? -EINVAL : 0; 1140 } 1141 1142 static int add_nr_metric_event(struct cpu_hw_events *cpuc, 1143 struct perf_event *event) 1144 { 1145 if (is_metric_event(event)) { 1146 if (cpuc->n_metric == INTEL_TD_METRIC_NUM) 1147 return -EINVAL; 1148 cpuc->n_metric++; 1149 cpuc->n_txn_metric++; 1150 } 1151 1152 return 0; 1153 } 1154 1155 static void del_nr_metric_event(struct cpu_hw_events *cpuc, 1156 struct perf_event *event) 1157 { 1158 if (is_metric_event(event)) 1159 cpuc->n_metric--; 1160 } 1161 1162 static int collect_event(struct cpu_hw_events *cpuc, struct perf_event *event, 1163 int max_count, int n) 1164 { 1165 union perf_capabilities intel_cap = hybrid(cpuc->pmu, intel_cap); 1166 1167 if (intel_cap.perf_metrics && add_nr_metric_event(cpuc, event)) 1168 return -EINVAL; 1169 1170 if (n >= max_count + cpuc->n_metric) 1171 return -EINVAL; 1172 1173 cpuc->event_list[n] = event; 1174 if (is_counter_pair(&event->hw)) { 1175 cpuc->n_pair++; 1176 cpuc->n_txn_pair++; 1177 } 1178 1179 return 0; 1180 } 1181 1182 /* 1183 * dogrp: true if must collect siblings events (group) 1184 * returns total number of events and error code 1185 */ 1186 static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader, bool dogrp) 1187 { 1188 struct perf_event *event; 1189 int n, max_count; 1190 1191 max_count = x86_pmu_num_counters(cpuc->pmu) + x86_pmu_num_counters_fixed(cpuc->pmu); 1192 1193 /* current number of events already accepted */ 1194 n = cpuc->n_events; 1195 if (!cpuc->n_events) 1196 cpuc->pebs_output = 0; 1197 1198 if (!cpuc->is_fake && leader->attr.precise_ip) { 1199 /* 1200 * For PEBS->PT, if !aux_event, the group leader (PT) went 1201 * away, the group was broken down and this singleton event 1202 * can't schedule any more. 1203 */ 1204 if (is_pebs_pt(leader) && !leader->aux_event) 1205 return -EINVAL; 1206 1207 /* 1208 * pebs_output: 0: no PEBS so far, 1: PT, 2: DS 1209 */ 1210 if (cpuc->pebs_output && 1211 cpuc->pebs_output != is_pebs_pt(leader) + 1) 1212 return -EINVAL; 1213 1214 cpuc->pebs_output = is_pebs_pt(leader) + 1; 1215 } 1216 1217 if (is_x86_event(leader)) { 1218 if (collect_event(cpuc, leader, max_count, n)) 1219 return -EINVAL; 1220 n++; 1221 } 1222 1223 if (!dogrp) 1224 return n; 1225 1226 for_each_sibling_event(event, leader) { 1227 if (!is_x86_event(event) || event->state <= PERF_EVENT_STATE_OFF) 1228 continue; 1229 1230 if (collect_event(cpuc, event, max_count, n)) 1231 return -EINVAL; 1232 1233 n++; 1234 } 1235 return n; 1236 } 1237 1238 static inline void x86_assign_hw_event(struct perf_event *event, 1239 struct cpu_hw_events *cpuc, int i) 1240 { 1241 struct hw_perf_event *hwc = &event->hw; 1242 int idx; 1243 1244 idx = hwc->idx = cpuc->assign[i]; 1245 hwc->last_cpu = smp_processor_id(); 1246 hwc->last_tag = ++cpuc->tags[i]; 1247 1248 static_call_cond(x86_pmu_assign)(event, idx); 1249 1250 switch (hwc->idx) { 1251 case INTEL_PMC_IDX_FIXED_BTS: 1252 case INTEL_PMC_IDX_FIXED_VLBR: 1253 hwc->config_base = 0; 1254 hwc->event_base = 0; 1255 break; 1256 1257 case INTEL_PMC_IDX_METRIC_BASE ... INTEL_PMC_IDX_METRIC_END: 1258 /* All the metric events are mapped onto the fixed counter 3. */ 1259 idx = INTEL_PMC_IDX_FIXED_SLOTS; 1260 fallthrough; 1261 case INTEL_PMC_IDX_FIXED ... INTEL_PMC_IDX_FIXED_BTS-1: 1262 hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL; 1263 hwc->event_base = x86_pmu_fixed_ctr_addr(idx - INTEL_PMC_IDX_FIXED); 1264 hwc->event_base_rdpmc = (idx - INTEL_PMC_IDX_FIXED) | 1265 INTEL_PMC_FIXED_RDPMC_BASE; 1266 break; 1267 1268 default: 1269 hwc->config_base = x86_pmu_config_addr(hwc->idx); 1270 hwc->event_base = x86_pmu_event_addr(hwc->idx); 1271 hwc->event_base_rdpmc = x86_pmu_rdpmc_index(hwc->idx); 1272 break; 1273 } 1274 } 1275 1276 /** 1277 * x86_perf_rdpmc_index - Return PMC counter used for event 1278 * @event: the perf_event to which the PMC counter was assigned 1279 * 1280 * The counter assigned to this performance event may change if interrupts 1281 * are enabled. This counter should thus never be used while interrupts are 1282 * enabled. Before this function is used to obtain the assigned counter the 1283 * event should be checked for validity using, for example, 1284 * perf_event_read_local(), within the same interrupt disabled section in 1285 * which this counter is planned to be used. 1286 * 1287 * Return: The index of the performance monitoring counter assigned to 1288 * @perf_event. 1289 */ 1290 int x86_perf_rdpmc_index(struct perf_event *event) 1291 { 1292 lockdep_assert_irqs_disabled(); 1293 1294 return event->hw.event_base_rdpmc; 1295 } 1296 1297 static inline int match_prev_assignment(struct hw_perf_event *hwc, 1298 struct cpu_hw_events *cpuc, 1299 int i) 1300 { 1301 return hwc->idx == cpuc->assign[i] && 1302 hwc->last_cpu == smp_processor_id() && 1303 hwc->last_tag == cpuc->tags[i]; 1304 } 1305 1306 static void x86_pmu_start(struct perf_event *event, int flags); 1307 1308 static void x86_pmu_enable(struct pmu *pmu) 1309 { 1310 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); 1311 struct perf_event *event; 1312 struct hw_perf_event *hwc; 1313 int i, added = cpuc->n_added; 1314 1315 if (!x86_pmu_initialized()) 1316 return; 1317 1318 if (cpuc->enabled) 1319 return; 1320 1321 if (cpuc->n_added) { 1322 int n_running = cpuc->n_events - cpuc->n_added; 1323 1324 /* 1325 * The late setup (after counters are scheduled) 1326 * is required for some cases, e.g., PEBS counters 1327 * snapshotting. Because an accurate counter index 1328 * is needed. 1329 */ 1330 static_call_cond(x86_pmu_late_setup)(); 1331 1332 /* 1333 * apply assignment obtained either from 1334 * hw_perf_group_sched_in() or x86_pmu_enable() 1335 * 1336 * step1: save events moving to new counters 1337 */ 1338 for (i = 0; i < n_running; i++) { 1339 event = cpuc->event_list[i]; 1340 hwc = &event->hw; 1341 1342 /* 1343 * we can avoid reprogramming counter if: 1344 * - assigned same counter as last time 1345 * - running on same CPU as last time 1346 * - no other event has used the counter since 1347 */ 1348 if (hwc->idx == -1 || 1349 match_prev_assignment(hwc, cpuc, i)) 1350 continue; 1351 1352 /* 1353 * Ensure we don't accidentally enable a stopped 1354 * counter simply because we rescheduled. 1355 */ 1356 if (hwc->state & PERF_HES_STOPPED) 1357 hwc->state |= PERF_HES_ARCH; 1358 1359 x86_pmu_stop(event, PERF_EF_UPDATE); 1360 cpuc->events[hwc->idx] = NULL; 1361 } 1362 1363 /* 1364 * step2: reprogram moved events into new counters 1365 */ 1366 for (i = 0; i < cpuc->n_events; i++) { 1367 event = cpuc->event_list[i]; 1368 hwc = &event->hw; 1369 1370 if (!match_prev_assignment(hwc, cpuc, i)) 1371 x86_assign_hw_event(event, cpuc, i); 1372 else if (i < n_running) 1373 continue; 1374 1375 if (hwc->state & PERF_HES_ARCH) 1376 continue; 1377 1378 /* 1379 * if cpuc->enabled = 0, then no wrmsr as 1380 * per x86_pmu_enable_event() 1381 */ 1382 cpuc->events[hwc->idx] = event; 1383 x86_pmu_start(event, PERF_EF_RELOAD); 1384 } 1385 cpuc->n_added = 0; 1386 perf_events_lapic_init(); 1387 } 1388 1389 cpuc->enabled = 1; 1390 barrier(); 1391 1392 static_call(x86_pmu_enable_all)(added); 1393 } 1394 1395 DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left); 1396 1397 /* 1398 * Set the next IRQ period, based on the hwc->period_left value. 1399 * To be called with the event disabled in hw: 1400 */ 1401 int x86_perf_event_set_period(struct perf_event *event) 1402 { 1403 struct hw_perf_event *hwc = &event->hw; 1404 s64 left = local64_read(&hwc->period_left); 1405 s64 period = hwc->sample_period; 1406 int ret = 0, idx = hwc->idx; 1407 1408 if (unlikely(!hwc->event_base)) 1409 return 0; 1410 1411 /* 1412 * If we are way outside a reasonable range then just skip forward: 1413 */ 1414 if (unlikely(left <= -period)) { 1415 left = period; 1416 local64_set(&hwc->period_left, left); 1417 hwc->last_period = period; 1418 ret = 1; 1419 } 1420 1421 if (unlikely(left <= 0)) { 1422 left += period; 1423 local64_set(&hwc->period_left, left); 1424 hwc->last_period = period; 1425 ret = 1; 1426 } 1427 /* 1428 * Quirk: certain CPUs dont like it if just 1 hw_event is left: 1429 */ 1430 if (unlikely(left < 2)) 1431 left = 2; 1432 1433 if (left > x86_pmu.max_period) 1434 left = x86_pmu.max_period; 1435 1436 static_call_cond(x86_pmu_limit_period)(event, &left); 1437 1438 this_cpu_write(pmc_prev_left[idx], left); 1439 1440 /* 1441 * The hw event starts counting from this event offset, 1442 * mark it to be able to extra future deltas: 1443 */ 1444 local64_set(&hwc->prev_count, (u64)-left); 1445 1446 wrmsrq(hwc->event_base, (u64)(-left) & x86_pmu.cntval_mask); 1447 1448 /* 1449 * Sign extend the Merge event counter's upper 16 bits since 1450 * we currently declare a 48-bit counter width 1451 */ 1452 if (is_counter_pair(hwc)) 1453 wrmsrq(x86_pmu_event_addr(idx + 1), 0xffff); 1454 1455 perf_event_update_userpage(event); 1456 1457 return ret; 1458 } 1459 1460 void x86_pmu_enable_event(struct perf_event *event) 1461 { 1462 if (__this_cpu_read(cpu_hw_events.enabled)) 1463 __x86_pmu_enable_event(&event->hw, 1464 ARCH_PERFMON_EVENTSEL_ENABLE); 1465 } 1466 1467 /* 1468 * Add a single event to the PMU. 1469 * 1470 * The event is added to the group of enabled events 1471 * but only if it can be scheduled with existing events. 1472 */ 1473 static int x86_pmu_add(struct perf_event *event, int flags) 1474 { 1475 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); 1476 struct hw_perf_event *hwc; 1477 int assign[X86_PMC_IDX_MAX]; 1478 int n, n0, ret; 1479 1480 hwc = &event->hw; 1481 1482 n0 = cpuc->n_events; 1483 ret = n = collect_events(cpuc, event, false); 1484 if (ret < 0) 1485 goto out; 1486 1487 hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED; 1488 if (!(flags & PERF_EF_START)) 1489 hwc->state |= PERF_HES_ARCH; 1490 1491 /* 1492 * If group events scheduling transaction was started, 1493 * skip the schedulability test here, it will be performed 1494 * at commit time (->commit_txn) as a whole. 1495 * 1496 * If commit fails, we'll call ->del() on all events 1497 * for which ->add() was called. 1498 */ 1499 if (cpuc->txn_flags & PERF_PMU_TXN_ADD) 1500 goto done_collect; 1501 1502 ret = static_call(x86_pmu_schedule_events)(cpuc, n, assign); 1503 if (ret) 1504 goto out; 1505 /* 1506 * copy new assignment, now we know it is possible 1507 * will be used by hw_perf_enable() 1508 */ 1509 memcpy(cpuc->assign, assign, n*sizeof(int)); 1510 1511 done_collect: 1512 /* 1513 * Commit the collect_events() state. See x86_pmu_del() and 1514 * x86_pmu_*_txn(). 1515 */ 1516 cpuc->n_events = n; 1517 cpuc->n_added += n - n0; 1518 cpuc->n_txn += n - n0; 1519 1520 /* 1521 * This is before x86_pmu_enable() will call x86_pmu_start(), 1522 * so we enable LBRs before an event needs them etc.. 1523 */ 1524 static_call_cond(x86_pmu_add)(event); 1525 1526 ret = 0; 1527 out: 1528 return ret; 1529 } 1530 1531 static void x86_pmu_start(struct perf_event *event, int flags) 1532 { 1533 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); 1534 int idx = event->hw.idx; 1535 1536 if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED))) 1537 return; 1538 1539 if (WARN_ON_ONCE(idx == -1)) 1540 return; 1541 1542 if (flags & PERF_EF_RELOAD) { 1543 WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE)); 1544 static_call(x86_pmu_set_period)(event); 1545 } 1546 1547 event->hw.state = 0; 1548 1549 __set_bit(idx, cpuc->active_mask); 1550 static_call(x86_pmu_enable)(event); 1551 perf_event_update_userpage(event); 1552 } 1553 1554 void perf_event_print_debug(void) 1555 { 1556 u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed; 1557 unsigned long *cntr_mask, *fixed_cntr_mask; 1558 struct event_constraint *pebs_constraints; 1559 struct cpu_hw_events *cpuc; 1560 u64 pebs, debugctl; 1561 int cpu, idx; 1562 1563 guard(irqsave)(); 1564 1565 cpu = smp_processor_id(); 1566 cpuc = &per_cpu(cpu_hw_events, cpu); 1567 cntr_mask = hybrid(cpuc->pmu, cntr_mask); 1568 fixed_cntr_mask = hybrid(cpuc->pmu, fixed_cntr_mask); 1569 pebs_constraints = hybrid(cpuc->pmu, pebs_constraints); 1570 1571 if (!*(u64 *)cntr_mask) 1572 return; 1573 1574 if (x86_pmu.version >= 2) { 1575 rdmsrq(MSR_CORE_PERF_GLOBAL_CTRL, ctrl); 1576 rdmsrq(MSR_CORE_PERF_GLOBAL_STATUS, status); 1577 rdmsrq(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow); 1578 rdmsrq(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed); 1579 1580 pr_info("\n"); 1581 pr_info("CPU#%d: ctrl: %016llx\n", cpu, ctrl); 1582 pr_info("CPU#%d: status: %016llx\n", cpu, status); 1583 pr_info("CPU#%d: overflow: %016llx\n", cpu, overflow); 1584 pr_info("CPU#%d: fixed: %016llx\n", cpu, fixed); 1585 if (pebs_constraints) { 1586 rdmsrq(MSR_IA32_PEBS_ENABLE, pebs); 1587 pr_info("CPU#%d: pebs: %016llx\n", cpu, pebs); 1588 } 1589 if (x86_pmu.lbr_nr) { 1590 rdmsrq(MSR_IA32_DEBUGCTLMSR, debugctl); 1591 pr_info("CPU#%d: debugctl: %016llx\n", cpu, debugctl); 1592 } 1593 } 1594 pr_info("CPU#%d: active: %016llx\n", cpu, *(u64 *)cpuc->active_mask); 1595 1596 for_each_set_bit(idx, cntr_mask, X86_PMC_IDX_MAX) { 1597 rdmsrq(x86_pmu_config_addr(idx), pmc_ctrl); 1598 rdmsrq(x86_pmu_event_addr(idx), pmc_count); 1599 1600 prev_left = per_cpu(pmc_prev_left[idx], cpu); 1601 1602 pr_info("CPU#%d: gen-PMC%d ctrl: %016llx\n", 1603 cpu, idx, pmc_ctrl); 1604 pr_info("CPU#%d: gen-PMC%d count: %016llx\n", 1605 cpu, idx, pmc_count); 1606 pr_info("CPU#%d: gen-PMC%d left: %016llx\n", 1607 cpu, idx, prev_left); 1608 } 1609 for_each_set_bit(idx, fixed_cntr_mask, X86_PMC_IDX_MAX) { 1610 if (fixed_counter_disabled(idx, cpuc->pmu)) 1611 continue; 1612 rdmsrq(x86_pmu_fixed_ctr_addr(idx), pmc_count); 1613 1614 pr_info("CPU#%d: fixed-PMC%d count: %016llx\n", 1615 cpu, idx, pmc_count); 1616 } 1617 } 1618 1619 void x86_pmu_stop(struct perf_event *event, int flags) 1620 { 1621 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); 1622 struct hw_perf_event *hwc = &event->hw; 1623 1624 if (test_bit(hwc->idx, cpuc->active_mask)) { 1625 static_call(x86_pmu_disable)(event); 1626 __clear_bit(hwc->idx, cpuc->active_mask); 1627 WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED); 1628 hwc->state |= PERF_HES_STOPPED; 1629 } 1630 1631 if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) { 1632 /* 1633 * Drain the remaining delta count out of a event 1634 * that we are disabling: 1635 */ 1636 static_call(x86_pmu_update)(event); 1637 hwc->state |= PERF_HES_UPTODATE; 1638 } 1639 } 1640 1641 static void x86_pmu_del(struct perf_event *event, int flags) 1642 { 1643 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); 1644 union perf_capabilities intel_cap = hybrid(cpuc->pmu, intel_cap); 1645 int i; 1646 1647 /* 1648 * If we're called during a txn, we only need to undo x86_pmu.add. 1649 * The events never got scheduled and ->cancel_txn will truncate 1650 * the event_list. 1651 * 1652 * XXX assumes any ->del() called during a TXN will only be on 1653 * an event added during that same TXN. 1654 */ 1655 if (cpuc->txn_flags & PERF_PMU_TXN_ADD) 1656 goto do_del; 1657 1658 __set_bit(event->hw.idx, cpuc->dirty); 1659 1660 /* 1661 * Not a TXN, therefore cleanup properly. 1662 */ 1663 x86_pmu_stop(event, PERF_EF_UPDATE); 1664 cpuc->events[event->hw.idx] = NULL; 1665 1666 for (i = 0; i < cpuc->n_events; i++) { 1667 if (event == cpuc->event_list[i]) 1668 break; 1669 } 1670 1671 if (WARN_ON_ONCE(i == cpuc->n_events)) /* called ->del() without ->add() ? */ 1672 return; 1673 1674 /* If we have a newly added event; make sure to decrease n_added. */ 1675 if (i >= cpuc->n_events - cpuc->n_added) 1676 --cpuc->n_added; 1677 1678 static_call_cond(x86_pmu_put_event_constraints)(cpuc, event); 1679 1680 /* Delete the array entry. */ 1681 while (++i < cpuc->n_events) { 1682 cpuc->event_list[i-1] = cpuc->event_list[i]; 1683 cpuc->event_constraint[i-1] = cpuc->event_constraint[i]; 1684 cpuc->assign[i-1] = cpuc->assign[i]; 1685 } 1686 cpuc->event_constraint[i-1] = NULL; 1687 --cpuc->n_events; 1688 if (intel_cap.perf_metrics) 1689 del_nr_metric_event(cpuc, event); 1690 1691 perf_event_update_userpage(event); 1692 1693 do_del: 1694 1695 /* 1696 * This is after x86_pmu_stop(); so we disable LBRs after any 1697 * event can need them etc.. 1698 */ 1699 static_call_cond(x86_pmu_del)(event); 1700 } 1701 1702 int x86_pmu_handle_irq(struct pt_regs *regs) 1703 { 1704 struct perf_sample_data data; 1705 struct cpu_hw_events *cpuc; 1706 struct perf_event *event; 1707 int idx, handled = 0; 1708 u64 last_period; 1709 u64 val; 1710 1711 cpuc = this_cpu_ptr(&cpu_hw_events); 1712 1713 /* 1714 * Some chipsets need to unmask the LVTPC in a particular spot 1715 * inside the nmi handler. As a result, the unmasking was pushed 1716 * into all the nmi handlers. 1717 * 1718 * This generic handler doesn't seem to have any issues where the 1719 * unmasking occurs so it was left at the top. 1720 */ 1721 apic_write(APIC_LVTPC, APIC_DM_NMI); 1722 1723 for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) { 1724 if (!test_bit(idx, cpuc->active_mask)) 1725 continue; 1726 1727 event = cpuc->events[idx]; 1728 last_period = event->hw.last_period; 1729 1730 val = static_call(x86_pmu_update)(event); 1731 if (val & (1ULL << (x86_pmu.cntval_bits - 1))) 1732 continue; 1733 1734 /* 1735 * event overflow 1736 */ 1737 handled++; 1738 1739 if (!static_call(x86_pmu_set_period)(event)) 1740 continue; 1741 1742 perf_sample_data_init(&data, 0, last_period); 1743 1744 perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL); 1745 1746 perf_event_overflow(event, &data, regs); 1747 } 1748 1749 if (handled) 1750 inc_irq_stat(apic_perf_irqs); 1751 1752 return handled; 1753 } 1754 1755 void perf_events_lapic_init(void) 1756 { 1757 if (!x86_pmu.apic || !x86_pmu_initialized()) 1758 return; 1759 1760 /* 1761 * Always use NMI for PMU 1762 */ 1763 apic_write(APIC_LVTPC, APIC_DM_NMI); 1764 } 1765 1766 #ifdef CONFIG_PERF_GUEST_MEDIATED_PMU 1767 void perf_load_guest_lvtpc(u32 guest_lvtpc) 1768 { 1769 u32 masked = guest_lvtpc & APIC_LVT_MASKED; 1770 1771 apic_write(APIC_LVTPC, 1772 APIC_DM_FIXED | PERF_GUEST_MEDIATED_PMI_VECTOR | masked); 1773 this_cpu_write(guest_lvtpc_loaded, true); 1774 } 1775 EXPORT_SYMBOL_FOR_KVM(perf_load_guest_lvtpc); 1776 1777 void perf_put_guest_lvtpc(void) 1778 { 1779 this_cpu_write(guest_lvtpc_loaded, false); 1780 apic_write(APIC_LVTPC, APIC_DM_NMI); 1781 } 1782 EXPORT_SYMBOL_FOR_KVM(perf_put_guest_lvtpc); 1783 #endif /* CONFIG_PERF_GUEST_MEDIATED_PMU */ 1784 1785 static int 1786 perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs) 1787 { 1788 u64 start_clock; 1789 u64 finish_clock; 1790 int ret; 1791 1792 /* 1793 * Ignore all NMIs when the CPU's LVTPC is configured to route PMIs to 1794 * PERF_GUEST_MEDIATED_PMI_VECTOR, i.e. when an NMI time can't be due 1795 * to a PMI. Attempting to handle a PMI while the guest's context is 1796 * loaded will generate false positives and clobber guest state. Note, 1797 * the LVTPC is switched to/from the dedicated mediated PMI IRQ vector 1798 * while host events are quiesced. 1799 */ 1800 if (this_cpu_read(guest_lvtpc_loaded)) 1801 return NMI_DONE; 1802 1803 /* 1804 * All PMUs/events that share this PMI handler should make sure to 1805 * increment active_events for their events. 1806 */ 1807 if (!atomic_read(&active_events)) 1808 return NMI_DONE; 1809 1810 start_clock = sched_clock(); 1811 ret = static_call(x86_pmu_handle_irq)(regs); 1812 finish_clock = sched_clock(); 1813 1814 perf_sample_event_took(finish_clock - start_clock); 1815 1816 return ret; 1817 } 1818 NOKPROBE_SYMBOL(perf_event_nmi_handler); 1819 1820 struct event_constraint emptyconstraint; 1821 struct event_constraint unconstrained; 1822 1823 static int x86_pmu_prepare_cpu(unsigned int cpu) 1824 { 1825 struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu); 1826 int i; 1827 1828 for (i = 0 ; i < X86_PERF_KFREE_MAX; i++) 1829 cpuc->kfree_on_online[i] = NULL; 1830 if (x86_pmu.cpu_prepare) 1831 return x86_pmu.cpu_prepare(cpu); 1832 return 0; 1833 } 1834 1835 static int x86_pmu_dead_cpu(unsigned int cpu) 1836 { 1837 if (x86_pmu.cpu_dead) 1838 x86_pmu.cpu_dead(cpu); 1839 return 0; 1840 } 1841 1842 static int x86_pmu_online_cpu(unsigned int cpu) 1843 { 1844 struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu); 1845 int i; 1846 1847 for (i = 0 ; i < X86_PERF_KFREE_MAX; i++) { 1848 kfree(cpuc->kfree_on_online[i]); 1849 cpuc->kfree_on_online[i] = NULL; 1850 } 1851 return 0; 1852 } 1853 1854 static int x86_pmu_starting_cpu(unsigned int cpu) 1855 { 1856 if (x86_pmu.cpu_starting) 1857 x86_pmu.cpu_starting(cpu); 1858 return 0; 1859 } 1860 1861 static int x86_pmu_dying_cpu(unsigned int cpu) 1862 { 1863 if (x86_pmu.cpu_dying) 1864 x86_pmu.cpu_dying(cpu); 1865 return 0; 1866 } 1867 1868 static void __init pmu_check_apic(void) 1869 { 1870 if (boot_cpu_has(X86_FEATURE_APIC)) 1871 return; 1872 1873 x86_pmu.apic = 0; 1874 pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n"); 1875 pr_info("no hardware sampling interrupt available.\n"); 1876 1877 /* 1878 * If we have a PMU initialized but no APIC 1879 * interrupts, we cannot sample hardware 1880 * events (user-space has to fall back and 1881 * sample via a hrtimer based software event): 1882 */ 1883 pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT; 1884 1885 } 1886 1887 static struct attribute_group x86_pmu_format_group __ro_after_init = { 1888 .name = "format", 1889 .attrs = NULL, 1890 }; 1891 1892 ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr, char *page) 1893 { 1894 struct perf_pmu_events_attr *pmu_attr = 1895 container_of(attr, struct perf_pmu_events_attr, attr); 1896 u64 config = 0; 1897 1898 if (pmu_attr->id < x86_pmu.max_events) 1899 config = x86_pmu.event_map(pmu_attr->id); 1900 1901 /* string trumps id */ 1902 if (pmu_attr->event_str) 1903 return sprintf(page, "%s\n", pmu_attr->event_str); 1904 1905 return x86_pmu.events_sysfs_show(page, config); 1906 } 1907 EXPORT_SYMBOL_GPL(events_sysfs_show); 1908 1909 ssize_t events_ht_sysfs_show(struct device *dev, struct device_attribute *attr, 1910 char *page) 1911 { 1912 struct perf_pmu_events_ht_attr *pmu_attr = 1913 container_of(attr, struct perf_pmu_events_ht_attr, attr); 1914 1915 /* 1916 * Report conditional events depending on Hyper-Threading. 1917 * 1918 * This is overly conservative as usually the HT special 1919 * handling is not needed if the other CPU thread is idle. 1920 * 1921 * Note this does not (and cannot) handle the case when thread 1922 * siblings are invisible, for example with virtualization 1923 * if they are owned by some other guest. The user tool 1924 * has to re-read when a thread sibling gets onlined later. 1925 */ 1926 return sprintf(page, "%s", 1927 topology_max_smt_threads() > 1 ? 1928 pmu_attr->event_str_ht : 1929 pmu_attr->event_str_noht); 1930 } 1931 1932 ssize_t events_hybrid_sysfs_show(struct device *dev, 1933 struct device_attribute *attr, 1934 char *page) 1935 { 1936 struct perf_pmu_events_hybrid_attr *pmu_attr = 1937 container_of(attr, struct perf_pmu_events_hybrid_attr, attr); 1938 struct x86_hybrid_pmu *pmu; 1939 const char *str, *next_str; 1940 int i; 1941 1942 if (hweight64(pmu_attr->pmu_type) == 1) 1943 return sprintf(page, "%s", pmu_attr->event_str); 1944 1945 /* 1946 * Hybrid PMUs may support the same event name, but with different 1947 * event encoding, e.g., the mem-loads event on an Atom PMU has 1948 * different event encoding from a Core PMU. 1949 * 1950 * The event_str includes all event encodings. Each event encoding 1951 * is divided by ";". The order of the event encodings must follow 1952 * the order of the hybrid PMU index. 1953 */ 1954 pmu = container_of(dev_get_drvdata(dev), struct x86_hybrid_pmu, pmu); 1955 1956 str = pmu_attr->event_str; 1957 for (i = 0; i < x86_pmu.num_hybrid_pmus; i++) { 1958 if (!(x86_pmu.hybrid_pmu[i].pmu_type & pmu_attr->pmu_type)) 1959 continue; 1960 if (x86_pmu.hybrid_pmu[i].pmu_type & pmu->pmu_type) { 1961 next_str = strchr(str, ';'); 1962 if (next_str) 1963 return snprintf(page, next_str - str + 1, "%s", str); 1964 else 1965 return sprintf(page, "%s", str); 1966 } 1967 str = strchr(str, ';'); 1968 str++; 1969 } 1970 1971 return 0; 1972 } 1973 EXPORT_SYMBOL_GPL(events_hybrid_sysfs_show); 1974 1975 EVENT_ATTR(cpu-cycles, CPU_CYCLES ); 1976 EVENT_ATTR(instructions, INSTRUCTIONS ); 1977 EVENT_ATTR(cache-references, CACHE_REFERENCES ); 1978 EVENT_ATTR(cache-misses, CACHE_MISSES ); 1979 EVENT_ATTR(branch-instructions, BRANCH_INSTRUCTIONS ); 1980 EVENT_ATTR(branch-misses, BRANCH_MISSES ); 1981 EVENT_ATTR(bus-cycles, BUS_CYCLES ); 1982 EVENT_ATTR(stalled-cycles-frontend, STALLED_CYCLES_FRONTEND ); 1983 EVENT_ATTR(stalled-cycles-backend, STALLED_CYCLES_BACKEND ); 1984 EVENT_ATTR(ref-cycles, REF_CPU_CYCLES ); 1985 1986 static struct attribute *empty_attrs; 1987 1988 static struct attribute *events_attr[] = { 1989 EVENT_PTR(CPU_CYCLES), 1990 EVENT_PTR(INSTRUCTIONS), 1991 EVENT_PTR(CACHE_REFERENCES), 1992 EVENT_PTR(CACHE_MISSES), 1993 EVENT_PTR(BRANCH_INSTRUCTIONS), 1994 EVENT_PTR(BRANCH_MISSES), 1995 EVENT_PTR(BUS_CYCLES), 1996 EVENT_PTR(STALLED_CYCLES_FRONTEND), 1997 EVENT_PTR(STALLED_CYCLES_BACKEND), 1998 EVENT_PTR(REF_CPU_CYCLES), 1999 NULL, 2000 }; 2001 2002 /* 2003 * Remove all undefined events (x86_pmu.event_map(id) == 0) 2004 * out of events_attr attributes. 2005 */ 2006 static umode_t 2007 is_visible(struct kobject *kobj, struct attribute *attr, int idx) 2008 { 2009 struct perf_pmu_events_attr *pmu_attr; 2010 2011 if (idx >= x86_pmu.max_events) 2012 return 0; 2013 2014 pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr.attr); 2015 /* str trumps id */ 2016 return pmu_attr->event_str || x86_pmu.event_map(idx) ? attr->mode : 0; 2017 } 2018 2019 static struct attribute_group x86_pmu_events_group __ro_after_init = { 2020 .name = "events", 2021 .attrs = events_attr, 2022 .is_visible = is_visible, 2023 }; 2024 2025 ssize_t x86_event_sysfs_show(char *page, u64 config, u64 event) 2026 { 2027 u64 umask = (config & ARCH_PERFMON_EVENTSEL_UMASK) >> 8; 2028 u64 cmask = (config & ARCH_PERFMON_EVENTSEL_CMASK) >> 24; 2029 bool edge = (config & ARCH_PERFMON_EVENTSEL_EDGE); 2030 bool pc = (config & ARCH_PERFMON_EVENTSEL_PIN_CONTROL); 2031 bool any = (config & ARCH_PERFMON_EVENTSEL_ANY); 2032 bool inv = (config & ARCH_PERFMON_EVENTSEL_INV); 2033 ssize_t ret; 2034 2035 /* 2036 * We have whole page size to spend and just little data 2037 * to write, so we can safely use sprintf. 2038 */ 2039 ret = sprintf(page, "event=0x%02llx", event); 2040 2041 if (umask) 2042 ret += sprintf(page + ret, ",umask=0x%02llx", umask); 2043 2044 if (edge) 2045 ret += sprintf(page + ret, ",edge"); 2046 2047 if (pc) 2048 ret += sprintf(page + ret, ",pc"); 2049 2050 if (any) 2051 ret += sprintf(page + ret, ",any"); 2052 2053 if (inv) 2054 ret += sprintf(page + ret, ",inv"); 2055 2056 if (cmask) 2057 ret += sprintf(page + ret, ",cmask=0x%02llx", cmask); 2058 2059 ret += sprintf(page + ret, "\n"); 2060 2061 return ret; 2062 } 2063 2064 static struct attribute_group x86_pmu_attr_group; 2065 static struct attribute_group x86_pmu_caps_group; 2066 2067 static void x86_pmu_static_call_update(void) 2068 { 2069 static_call_update(x86_pmu_handle_irq, x86_pmu.handle_irq); 2070 static_call_update(x86_pmu_disable_all, x86_pmu.disable_all); 2071 static_call_update(x86_pmu_enable_all, x86_pmu.enable_all); 2072 static_call_update(x86_pmu_enable, x86_pmu.enable); 2073 static_call_update(x86_pmu_disable, x86_pmu.disable); 2074 2075 static_call_update(x86_pmu_assign, x86_pmu.assign); 2076 2077 static_call_update(x86_pmu_add, x86_pmu.add); 2078 static_call_update(x86_pmu_del, x86_pmu.del); 2079 static_call_update(x86_pmu_read, x86_pmu.read); 2080 2081 static_call_update(x86_pmu_set_period, x86_pmu.set_period); 2082 static_call_update(x86_pmu_update, x86_pmu.update); 2083 static_call_update(x86_pmu_limit_period, x86_pmu.limit_period); 2084 2085 static_call_update(x86_pmu_schedule_events, x86_pmu.schedule_events); 2086 static_call_update(x86_pmu_get_event_constraints, x86_pmu.get_event_constraints); 2087 static_call_update(x86_pmu_put_event_constraints, x86_pmu.put_event_constraints); 2088 2089 static_call_update(x86_pmu_start_scheduling, x86_pmu.start_scheduling); 2090 static_call_update(x86_pmu_commit_scheduling, x86_pmu.commit_scheduling); 2091 static_call_update(x86_pmu_stop_scheduling, x86_pmu.stop_scheduling); 2092 2093 static_call_update(x86_pmu_sched_task, x86_pmu.sched_task); 2094 2095 static_call_update(x86_pmu_drain_pebs, x86_pmu.drain_pebs); 2096 static_call_update(x86_pmu_pebs_aliases, x86_pmu.pebs_aliases); 2097 2098 static_call_update(x86_pmu_guest_get_msrs, x86_pmu.guest_get_msrs); 2099 static_call_update(x86_pmu_filter, x86_pmu.filter); 2100 2101 static_call_update(x86_pmu_late_setup, x86_pmu.late_setup); 2102 2103 static_call_update(x86_pmu_pebs_enable, x86_pmu.pebs_enable); 2104 static_call_update(x86_pmu_pebs_disable, x86_pmu.pebs_disable); 2105 static_call_update(x86_pmu_pebs_enable_all, x86_pmu.pebs_enable_all); 2106 static_call_update(x86_pmu_pebs_disable_all, x86_pmu.pebs_disable_all); 2107 } 2108 2109 static void _x86_pmu_read(struct perf_event *event) 2110 { 2111 static_call(x86_pmu_update)(event); 2112 } 2113 2114 void x86_pmu_show_pmu_cap(struct pmu *pmu) 2115 { 2116 pr_info("... version: %d\n", x86_pmu.version); 2117 pr_info("... bit width: %d\n", x86_pmu.cntval_bits); 2118 pr_info("... generic counters: %d\n", x86_pmu_num_counters(pmu)); 2119 pr_info("... generic bitmap: %016llx\n", hybrid(pmu, cntr_mask64)); 2120 pr_info("... fixed-purpose counters: %d\n", x86_pmu_num_counters_fixed(pmu)); 2121 pr_info("... fixed-purpose bitmap: %016llx\n", hybrid(pmu, fixed_cntr_mask64)); 2122 pr_info("... value mask: %016llx\n", x86_pmu.cntval_mask); 2123 pr_info("... max period: %016llx\n", x86_pmu.max_period); 2124 pr_info("... global_ctrl mask: %016llx\n", hybrid(pmu, intel_ctrl)); 2125 } 2126 2127 static int __init init_hw_perf_events(void) 2128 { 2129 struct x86_pmu_quirk *quirk; 2130 int err; 2131 2132 pr_info("Performance Events: "); 2133 2134 switch (boot_cpu_data.x86_vendor) { 2135 case X86_VENDOR_INTEL: 2136 err = intel_pmu_init(); 2137 break; 2138 case X86_VENDOR_AMD: 2139 err = amd_pmu_init(); 2140 break; 2141 case X86_VENDOR_HYGON: 2142 err = amd_pmu_init(); 2143 x86_pmu.name = "HYGON"; 2144 break; 2145 case X86_VENDOR_ZHAOXIN: 2146 case X86_VENDOR_CENTAUR: 2147 err = zhaoxin_pmu_init(); 2148 break; 2149 default: 2150 err = -ENOTSUPP; 2151 } 2152 if (err != 0) { 2153 pr_cont("no PMU driver, software events only.\n"); 2154 err = 0; 2155 goto out_bad_pmu; 2156 } 2157 2158 pmu_check_apic(); 2159 2160 /* sanity check that the hardware exists or is emulated */ 2161 if (!check_hw_exists(&pmu, x86_pmu.cntr_mask, x86_pmu.fixed_cntr_mask)) 2162 goto out_bad_pmu; 2163 2164 pr_cont("%s PMU driver.\n", x86_pmu.name); 2165 2166 /* enable userspace RDPMC usage by default */ 2167 x86_pmu.attr_rdpmc = X86_USER_RDPMC_CONDITIONAL_ENABLE; 2168 2169 for (quirk = x86_pmu.quirks; quirk; quirk = quirk->next) 2170 quirk->func(); 2171 2172 if (!x86_pmu.intel_ctrl) 2173 x86_pmu.intel_ctrl = x86_pmu.cntr_mask64; 2174 2175 if (!x86_pmu.config_mask) 2176 x86_pmu.config_mask = X86_RAW_EVENT_MASK; 2177 2178 perf_events_lapic_init(); 2179 register_nmi_handler(NMI_LOCAL, perf_event_nmi_handler, 0, "PMI"); 2180 2181 unconstrained = (struct event_constraint) 2182 __EVENT_CONSTRAINT(0, x86_pmu.cntr_mask64, 2183 0, x86_pmu_num_counters(NULL), 0, 0); 2184 2185 x86_pmu_format_group.attrs = x86_pmu.format_attrs; 2186 2187 if (!x86_pmu.events_sysfs_show) 2188 x86_pmu_events_group.attrs = &empty_attrs; 2189 2190 pmu.attr_update = x86_pmu.attr_update; 2191 2192 if (!is_hybrid()) 2193 x86_pmu_show_pmu_cap(NULL); 2194 2195 if (!x86_pmu.read) 2196 x86_pmu.read = _x86_pmu_read; 2197 2198 if (!x86_pmu.guest_get_msrs) 2199 x86_pmu.guest_get_msrs = (void *)&__static_call_return0; 2200 2201 if (!x86_pmu.set_period) 2202 x86_pmu.set_period = x86_perf_event_set_period; 2203 2204 if (!x86_pmu.update) 2205 x86_pmu.update = x86_perf_event_update; 2206 2207 x86_pmu_static_call_update(); 2208 2209 /* 2210 * Install callbacks. Core will call them for each online 2211 * cpu. 2212 */ 2213 err = cpuhp_setup_state(CPUHP_PERF_X86_PREPARE, "perf/x86:prepare", 2214 x86_pmu_prepare_cpu, x86_pmu_dead_cpu); 2215 if (err) 2216 return err; 2217 2218 err = cpuhp_setup_state(CPUHP_AP_PERF_X86_STARTING, 2219 "perf/x86:starting", x86_pmu_starting_cpu, 2220 x86_pmu_dying_cpu); 2221 if (err) 2222 goto out; 2223 2224 err = cpuhp_setup_state(CPUHP_AP_PERF_X86_ONLINE, "perf/x86:online", 2225 x86_pmu_online_cpu, NULL); 2226 if (err) 2227 goto out1; 2228 2229 if (!is_hybrid()) { 2230 err = perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW); 2231 if (err) 2232 goto out2; 2233 } else { 2234 struct x86_hybrid_pmu *hybrid_pmu; 2235 int i, j; 2236 2237 for (i = 0; i < x86_pmu.num_hybrid_pmus; i++) { 2238 hybrid_pmu = &x86_pmu.hybrid_pmu[i]; 2239 2240 hybrid_pmu->pmu = pmu; 2241 hybrid_pmu->pmu.type = -1; 2242 hybrid_pmu->pmu.attr_update = x86_pmu.attr_update; 2243 hybrid_pmu->pmu.capabilities |= PERF_PMU_CAP_EXTENDED_HW_TYPE; 2244 2245 err = perf_pmu_register(&hybrid_pmu->pmu, hybrid_pmu->name, 2246 (hybrid_pmu->pmu_type == hybrid_big) ? PERF_TYPE_RAW : -1); 2247 if (err) 2248 break; 2249 } 2250 2251 if (i < x86_pmu.num_hybrid_pmus) { 2252 for (j = 0; j < i; j++) 2253 perf_pmu_unregister(&x86_pmu.hybrid_pmu[j].pmu); 2254 pr_warn("Failed to register hybrid PMUs\n"); 2255 kfree(x86_pmu.hybrid_pmu); 2256 x86_pmu.hybrid_pmu = NULL; 2257 x86_pmu.num_hybrid_pmus = 0; 2258 goto out2; 2259 } 2260 } 2261 2262 return 0; 2263 2264 out2: 2265 cpuhp_remove_state(CPUHP_AP_PERF_X86_ONLINE); 2266 out1: 2267 cpuhp_remove_state(CPUHP_AP_PERF_X86_STARTING); 2268 out: 2269 cpuhp_remove_state(CPUHP_PERF_X86_PREPARE); 2270 out_bad_pmu: 2271 memset(&x86_pmu, 0, sizeof(x86_pmu)); 2272 return err; 2273 } 2274 early_initcall(init_hw_perf_events); 2275 2276 static void x86_pmu_read(struct perf_event *event) 2277 { 2278 static_call(x86_pmu_read)(event); 2279 } 2280 2281 /* 2282 * Start group events scheduling transaction 2283 * Set the flag to make pmu::enable() not perform the 2284 * schedulability test, it will be performed at commit time 2285 * 2286 * We only support PERF_PMU_TXN_ADD transactions. Save the 2287 * transaction flags but otherwise ignore non-PERF_PMU_TXN_ADD 2288 * transactions. 2289 */ 2290 static void x86_pmu_start_txn(struct pmu *pmu, unsigned int txn_flags) 2291 { 2292 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); 2293 2294 WARN_ON_ONCE(cpuc->txn_flags); /* txn already in flight */ 2295 2296 cpuc->txn_flags = txn_flags; 2297 if (txn_flags & ~PERF_PMU_TXN_ADD) 2298 return; 2299 2300 perf_pmu_disable(pmu); 2301 __this_cpu_write(cpu_hw_events.n_txn, 0); 2302 __this_cpu_write(cpu_hw_events.n_txn_pair, 0); 2303 __this_cpu_write(cpu_hw_events.n_txn_metric, 0); 2304 } 2305 2306 /* 2307 * Stop group events scheduling transaction 2308 * Clear the flag and pmu::enable() will perform the 2309 * schedulability test. 2310 */ 2311 static void x86_pmu_cancel_txn(struct pmu *pmu) 2312 { 2313 unsigned int txn_flags; 2314 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); 2315 2316 WARN_ON_ONCE(!cpuc->txn_flags); /* no txn in flight */ 2317 2318 txn_flags = cpuc->txn_flags; 2319 cpuc->txn_flags = 0; 2320 if (txn_flags & ~PERF_PMU_TXN_ADD) 2321 return; 2322 2323 /* 2324 * Truncate collected array by the number of events added in this 2325 * transaction. See x86_pmu_add() and x86_pmu_*_txn(). 2326 */ 2327 __this_cpu_sub(cpu_hw_events.n_added, __this_cpu_read(cpu_hw_events.n_txn)); 2328 __this_cpu_sub(cpu_hw_events.n_events, __this_cpu_read(cpu_hw_events.n_txn)); 2329 __this_cpu_sub(cpu_hw_events.n_pair, __this_cpu_read(cpu_hw_events.n_txn_pair)); 2330 __this_cpu_sub(cpu_hw_events.n_metric, __this_cpu_read(cpu_hw_events.n_txn_metric)); 2331 perf_pmu_enable(pmu); 2332 } 2333 2334 /* 2335 * Commit group events scheduling transaction 2336 * Perform the group schedulability test as a whole 2337 * Return 0 if success 2338 * 2339 * Does not cancel the transaction on failure; expects the caller to do this. 2340 */ 2341 static int x86_pmu_commit_txn(struct pmu *pmu) 2342 { 2343 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); 2344 int assign[X86_PMC_IDX_MAX]; 2345 int n, ret; 2346 2347 WARN_ON_ONCE(!cpuc->txn_flags); /* no txn in flight */ 2348 2349 if (cpuc->txn_flags & ~PERF_PMU_TXN_ADD) { 2350 cpuc->txn_flags = 0; 2351 return 0; 2352 } 2353 2354 n = cpuc->n_events; 2355 2356 if (!x86_pmu_initialized()) 2357 return -EAGAIN; 2358 2359 ret = static_call(x86_pmu_schedule_events)(cpuc, n, assign); 2360 if (ret) 2361 return ret; 2362 2363 /* 2364 * copy new assignment, now we know it is possible 2365 * will be used by hw_perf_enable() 2366 */ 2367 memcpy(cpuc->assign, assign, n*sizeof(int)); 2368 2369 cpuc->txn_flags = 0; 2370 perf_pmu_enable(pmu); 2371 return 0; 2372 } 2373 /* 2374 * a fake_cpuc is used to validate event groups. Due to 2375 * the extra reg logic, we need to also allocate a fake 2376 * per_core and per_cpu structure. Otherwise, group events 2377 * using extra reg may conflict without the kernel being 2378 * able to catch this when the last event gets added to 2379 * the group. 2380 */ 2381 static void free_fake_cpuc(struct cpu_hw_events *cpuc) 2382 { 2383 intel_cpuc_finish(cpuc); 2384 kfree(cpuc); 2385 } 2386 2387 static struct cpu_hw_events *allocate_fake_cpuc(struct pmu *event_pmu) 2388 { 2389 struct cpu_hw_events *cpuc; 2390 int cpu; 2391 2392 cpuc = kzalloc(sizeof(*cpuc), GFP_KERNEL); 2393 if (!cpuc) 2394 return ERR_PTR(-ENOMEM); 2395 cpuc->is_fake = 1; 2396 2397 if (is_hybrid()) { 2398 struct x86_hybrid_pmu *h_pmu; 2399 2400 h_pmu = hybrid_pmu(event_pmu); 2401 if (cpumask_empty(&h_pmu->supported_cpus)) 2402 goto error; 2403 cpu = cpumask_first(&h_pmu->supported_cpus); 2404 } else 2405 cpu = raw_smp_processor_id(); 2406 cpuc->pmu = event_pmu; 2407 2408 if (intel_cpuc_prepare(cpuc, cpu)) 2409 goto error; 2410 2411 return cpuc; 2412 error: 2413 free_fake_cpuc(cpuc); 2414 return ERR_PTR(-ENOMEM); 2415 } 2416 2417 /* 2418 * validate that we can schedule this event 2419 */ 2420 static int validate_event(struct perf_event *event) 2421 { 2422 struct cpu_hw_events *fake_cpuc; 2423 struct event_constraint *c; 2424 int ret = 0; 2425 2426 fake_cpuc = allocate_fake_cpuc(event->pmu); 2427 if (IS_ERR(fake_cpuc)) 2428 return PTR_ERR(fake_cpuc); 2429 2430 c = x86_pmu.get_event_constraints(fake_cpuc, 0, event); 2431 2432 if (!c || !c->weight) 2433 ret = -EINVAL; 2434 2435 if (x86_pmu.put_event_constraints) 2436 x86_pmu.put_event_constraints(fake_cpuc, event); 2437 2438 free_fake_cpuc(fake_cpuc); 2439 2440 return ret; 2441 } 2442 2443 /* 2444 * validate a single event group 2445 * 2446 * validation include: 2447 * - check events are compatible which each other 2448 * - events do not compete for the same counter 2449 * - number of events <= number of counters 2450 * 2451 * validation ensures the group can be loaded onto the 2452 * PMU if it was the only group available. 2453 */ 2454 static int validate_group(struct perf_event *event) 2455 { 2456 struct perf_event *leader = event->group_leader; 2457 struct cpu_hw_events *fake_cpuc; 2458 int ret = -EINVAL, n; 2459 2460 /* 2461 * Reject events from different hybrid PMUs. 2462 */ 2463 if (is_hybrid()) { 2464 struct perf_event *sibling; 2465 struct pmu *pmu = NULL; 2466 2467 if (is_x86_event(leader)) 2468 pmu = leader->pmu; 2469 2470 for_each_sibling_event(sibling, leader) { 2471 if (!is_x86_event(sibling)) 2472 continue; 2473 if (!pmu) 2474 pmu = sibling->pmu; 2475 else if (pmu != sibling->pmu) 2476 return ret; 2477 } 2478 } 2479 2480 fake_cpuc = allocate_fake_cpuc(event->pmu); 2481 if (IS_ERR(fake_cpuc)) 2482 return PTR_ERR(fake_cpuc); 2483 /* 2484 * the event is not yet connected with its 2485 * siblings therefore we must first collect 2486 * existing siblings, then add the new event 2487 * before we can simulate the scheduling 2488 */ 2489 n = collect_events(fake_cpuc, leader, true); 2490 if (n < 0) 2491 goto out; 2492 2493 fake_cpuc->n_events = n; 2494 n = collect_events(fake_cpuc, event, false); 2495 if (n < 0) 2496 goto out; 2497 2498 fake_cpuc->n_events = 0; 2499 ret = x86_pmu.schedule_events(fake_cpuc, n, NULL); 2500 2501 out: 2502 free_fake_cpuc(fake_cpuc); 2503 return ret; 2504 } 2505 2506 static int x86_pmu_event_init(struct perf_event *event) 2507 { 2508 struct x86_hybrid_pmu *pmu = NULL; 2509 int err; 2510 2511 if ((event->attr.type != event->pmu->type) && 2512 (event->attr.type != PERF_TYPE_HARDWARE) && 2513 (event->attr.type != PERF_TYPE_HW_CACHE)) 2514 return -ENOENT; 2515 2516 if (is_hybrid() && (event->cpu != -1)) { 2517 pmu = hybrid_pmu(event->pmu); 2518 if (!cpumask_test_cpu(event->cpu, &pmu->supported_cpus)) 2519 return -ENOENT; 2520 } 2521 2522 err = __x86_pmu_event_init(event); 2523 if (!err) { 2524 if (event->group_leader != event) 2525 err = validate_group(event); 2526 else 2527 err = validate_event(event); 2528 } 2529 if (err) { 2530 if (event->destroy) 2531 event->destroy(event); 2532 event->destroy = NULL; 2533 } 2534 2535 if (READ_ONCE(x86_pmu.attr_rdpmc) && 2536 !(event->hw.flags & PERF_X86_EVENT_LARGE_PEBS)) 2537 event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT; 2538 2539 return err; 2540 } 2541 2542 void perf_clear_dirty_counters(void) 2543 { 2544 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); 2545 int i; 2546 2547 /* Don't need to clear the assigned counter. */ 2548 for (i = 0; i < cpuc->n_events; i++) 2549 __clear_bit(cpuc->assign[i], cpuc->dirty); 2550 2551 if (bitmap_empty(cpuc->dirty, X86_PMC_IDX_MAX)) 2552 return; 2553 2554 for_each_set_bit(i, cpuc->dirty, X86_PMC_IDX_MAX) { 2555 if (i >= INTEL_PMC_IDX_FIXED) { 2556 /* Metrics and fake events don't have corresponding HW counters. */ 2557 if (!test_bit(i - INTEL_PMC_IDX_FIXED, hybrid(cpuc->pmu, fixed_cntr_mask))) 2558 continue; 2559 2560 wrmsrq(x86_pmu_fixed_ctr_addr(i - INTEL_PMC_IDX_FIXED), 0); 2561 } else { 2562 wrmsrq(x86_pmu_event_addr(i), 0); 2563 } 2564 } 2565 2566 bitmap_zero(cpuc->dirty, X86_PMC_IDX_MAX); 2567 } 2568 2569 static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm) 2570 { 2571 if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT)) 2572 return; 2573 2574 /* 2575 * This function relies on not being called concurrently in two 2576 * tasks in the same mm. Otherwise one task could observe 2577 * perf_rdpmc_allowed > 1 and return all the way back to 2578 * userspace with CR4.PCE clear while another task is still 2579 * doing on_each_cpu_mask() to propagate CR4.PCE. 2580 * 2581 * For now, this can't happen because all callers hold mmap_lock 2582 * for write. If this changes, we'll need a different solution. 2583 */ 2584 mmap_assert_write_locked(mm); 2585 2586 if (atomic_inc_return(&mm->context.perf_rdpmc_allowed) == 1) 2587 on_each_cpu_mask(mm_cpumask(mm), cr4_update_pce, NULL, 1); 2588 } 2589 2590 static void x86_pmu_event_unmapped(struct perf_event *event, struct mm_struct *mm) 2591 { 2592 if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT)) 2593 return; 2594 2595 if (atomic_dec_and_test(&mm->context.perf_rdpmc_allowed)) 2596 on_each_cpu_mask(mm_cpumask(mm), cr4_update_pce, NULL, 1); 2597 } 2598 2599 static int x86_pmu_event_idx(struct perf_event *event) 2600 { 2601 struct hw_perf_event *hwc = &event->hw; 2602 2603 if (!(hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT)) 2604 return 0; 2605 2606 if (is_metric_idx(hwc->idx)) 2607 return INTEL_PMC_FIXED_RDPMC_METRICS + 1; 2608 else 2609 return hwc->event_base_rdpmc + 1; 2610 } 2611 2612 static ssize_t get_attr_rdpmc(struct device *cdev, 2613 struct device_attribute *attr, 2614 char *buf) 2615 { 2616 return snprintf(buf, 40, "%d\n", x86_pmu.attr_rdpmc); 2617 } 2618 2619 /* 2620 * Behaviors of rdpmc value: 2621 * - rdpmc = 0 2622 * global user space rdpmc and counter level's user space rdpmc of all 2623 * counters are both disabled. 2624 * - rdpmc = 1 2625 * global user space rdpmc is enabled in mmap enabled time window and 2626 * counter level's user space rdpmc is enabled for only non system-wide 2627 * events. Counter level's user space rdpmc of system-wide events is 2628 * still disabled by default. This won't introduce counter data leak for 2629 * non system-wide events since their count data would be cleared when 2630 * context switches. 2631 * - rdpmc = 2 2632 * global user space rdpmc and counter level's user space rdpmc of all 2633 * counters are enabled unconditionally. 2634 * 2635 * Suppose the rdpmc value won't be changed frequently, don't dynamically 2636 * reschedule events to make the new rpdmc value take effect on active perf 2637 * events immediately, the new rdpmc value would only impact the new 2638 * activated perf events. This makes code simpler and cleaner. 2639 */ 2640 static ssize_t set_attr_rdpmc(struct device *cdev, 2641 struct device_attribute *attr, 2642 const char *buf, size_t count) 2643 { 2644 static DEFINE_MUTEX(rdpmc_mutex); 2645 unsigned long val; 2646 ssize_t ret; 2647 2648 ret = kstrtoul(buf, 0, &val); 2649 if (ret) 2650 return ret; 2651 2652 if (val > 2) 2653 return -EINVAL; 2654 2655 if (x86_pmu.attr_rdpmc_broken) 2656 return -ENOTSUPP; 2657 2658 guard(mutex)(&rdpmc_mutex); 2659 2660 if (val != x86_pmu.attr_rdpmc) { 2661 /* 2662 * Changing into or out of never available or always available, 2663 * aka perf-event-bypassing mode. This path is extremely slow, 2664 * but only root can trigger it, so it's okay. 2665 */ 2666 if (val == 0) 2667 static_branch_inc(&rdpmc_never_available_key); 2668 else if (x86_pmu.attr_rdpmc == X86_USER_RDPMC_NEVER_ENABLE) 2669 static_branch_dec(&rdpmc_never_available_key); 2670 2671 if (val == 2) 2672 static_branch_inc(&rdpmc_always_available_key); 2673 else if (x86_pmu.attr_rdpmc == X86_USER_RDPMC_ALWAYS_ENABLE) 2674 static_branch_dec(&rdpmc_always_available_key); 2675 2676 on_each_cpu(cr4_update_pce, NULL, 1); 2677 x86_pmu.attr_rdpmc = val; 2678 } 2679 2680 return count; 2681 } 2682 2683 static DEVICE_ATTR(rdpmc, S_IRUSR | S_IWUSR, get_attr_rdpmc, set_attr_rdpmc); 2684 2685 static struct attribute *x86_pmu_attrs[] = { 2686 &dev_attr_rdpmc.attr, 2687 NULL, 2688 }; 2689 2690 static struct attribute_group x86_pmu_attr_group __ro_after_init = { 2691 .attrs = x86_pmu_attrs, 2692 }; 2693 2694 static ssize_t max_precise_show(struct device *cdev, 2695 struct device_attribute *attr, 2696 char *buf) 2697 { 2698 struct pmu *pmu = dev_get_drvdata(cdev); 2699 2700 return snprintf(buf, PAGE_SIZE, "%d\n", x86_pmu_max_precise(pmu)); 2701 } 2702 2703 static DEVICE_ATTR_RO(max_precise); 2704 2705 static struct attribute *x86_pmu_caps_attrs[] = { 2706 &dev_attr_max_precise.attr, 2707 NULL 2708 }; 2709 2710 static struct attribute_group x86_pmu_caps_group __ro_after_init = { 2711 .name = "caps", 2712 .attrs = x86_pmu_caps_attrs, 2713 }; 2714 2715 static const struct attribute_group *x86_pmu_attr_groups[] = { 2716 &x86_pmu_attr_group, 2717 &x86_pmu_format_group, 2718 &x86_pmu_events_group, 2719 &x86_pmu_caps_group, 2720 NULL, 2721 }; 2722 2723 static void x86_pmu_sched_task(struct perf_event_pmu_context *pmu_ctx, 2724 struct task_struct *task, bool sched_in) 2725 { 2726 static_call_cond(x86_pmu_sched_task)(pmu_ctx, task, sched_in); 2727 } 2728 2729 void perf_check_microcode(void) 2730 { 2731 if (x86_pmu.check_microcode) 2732 x86_pmu.check_microcode(); 2733 } 2734 2735 static int x86_pmu_check_period(struct perf_event *event, u64 value) 2736 { 2737 if (x86_pmu.check_period && x86_pmu.check_period(event, value)) 2738 return -EINVAL; 2739 2740 if (value && x86_pmu.limit_period) { 2741 s64 left = value; 2742 x86_pmu.limit_period(event, &left); 2743 if (left > value) 2744 return -EINVAL; 2745 } 2746 2747 return 0; 2748 } 2749 2750 static int x86_pmu_aux_output_match(struct perf_event *event) 2751 { 2752 if (!(pmu.capabilities & PERF_PMU_CAP_AUX_OUTPUT)) 2753 return 0; 2754 2755 if (x86_pmu.aux_output_match) 2756 return x86_pmu.aux_output_match(event); 2757 2758 return 0; 2759 } 2760 2761 static bool x86_pmu_filter(struct pmu *pmu, int cpu) 2762 { 2763 bool ret = false; 2764 2765 static_call_cond(x86_pmu_filter)(pmu, cpu, &ret); 2766 2767 return ret; 2768 } 2769 2770 static struct pmu pmu = { 2771 .pmu_enable = x86_pmu_enable, 2772 .pmu_disable = x86_pmu_disable, 2773 2774 .attr_groups = x86_pmu_attr_groups, 2775 2776 .event_init = x86_pmu_event_init, 2777 2778 .event_mapped = x86_pmu_event_mapped, 2779 .event_unmapped = x86_pmu_event_unmapped, 2780 2781 .add = x86_pmu_add, 2782 .del = x86_pmu_del, 2783 .start = x86_pmu_start, 2784 .stop = x86_pmu_stop, 2785 .read = x86_pmu_read, 2786 2787 .start_txn = x86_pmu_start_txn, 2788 .cancel_txn = x86_pmu_cancel_txn, 2789 .commit_txn = x86_pmu_commit_txn, 2790 2791 .event_idx = x86_pmu_event_idx, 2792 .sched_task = x86_pmu_sched_task, 2793 .check_period = x86_pmu_check_period, 2794 2795 .aux_output_match = x86_pmu_aux_output_match, 2796 2797 .filter = x86_pmu_filter, 2798 }; 2799 2800 void arch_perf_update_userpage(struct perf_event *event, 2801 struct perf_event_mmap_page *userpg, u64 now) 2802 { 2803 struct cyc2ns_data data; 2804 u64 offset; 2805 2806 userpg->cap_user_time = 0; 2807 userpg->cap_user_time_zero = 0; 2808 userpg->cap_user_rdpmc = 2809 !!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT); 2810 userpg->pmc_width = x86_pmu.cntval_bits; 2811 2812 if (!using_native_sched_clock() || !sched_clock_stable()) 2813 return; 2814 2815 cyc2ns_read_begin(&data); 2816 2817 offset = data.cyc2ns_offset + __sched_clock_offset; 2818 2819 /* 2820 * Internal timekeeping for enabled/running/stopped times 2821 * is always in the local_clock domain. 2822 */ 2823 userpg->cap_user_time = 1; 2824 userpg->time_mult = data.cyc2ns_mul; 2825 userpg->time_shift = data.cyc2ns_shift; 2826 userpg->time_offset = offset - now; 2827 2828 /* 2829 * cap_user_time_zero doesn't make sense when we're using a different 2830 * time base for the records. 2831 */ 2832 if (!event->attr.use_clockid) { 2833 userpg->cap_user_time_zero = 1; 2834 userpg->time_zero = offset; 2835 } 2836 2837 cyc2ns_read_end(); 2838 } 2839 2840 /* 2841 * Determine whether the regs were taken from an irq/exception handler rather 2842 * than from perf_arch_fetch_caller_regs(). 2843 */ 2844 static bool perf_hw_regs(struct pt_regs *regs) 2845 { 2846 return regs->flags & X86_EFLAGS_FIXED; 2847 } 2848 2849 void 2850 perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) 2851 { 2852 struct unwind_state state; 2853 unsigned long addr; 2854 2855 if (perf_guest_state()) { 2856 /* TODO: We don't support guest os callchain now */ 2857 return; 2858 } 2859 2860 if (perf_hw_regs(regs)) { 2861 if (perf_callchain_store(entry, regs->ip)) 2862 return; 2863 unwind_start(&state, current, regs, NULL); 2864 } else { 2865 unwind_start(&state, current, NULL, (void *)regs->sp); 2866 } 2867 2868 for (; !unwind_done(&state); unwind_next_frame(&state)) { 2869 addr = unwind_get_return_address(&state); 2870 if (!addr || perf_callchain_store(entry, addr)) 2871 return; 2872 } 2873 } 2874 2875 static inline int 2876 valid_user_frame(const void __user *fp, unsigned long size) 2877 { 2878 return __access_ok(fp, size); 2879 } 2880 2881 static unsigned long get_segment_base(unsigned int segment) 2882 { 2883 struct desc_struct *desc; 2884 unsigned int idx = segment >> 3; 2885 2886 if ((segment & SEGMENT_TI_MASK) == SEGMENT_LDT) { 2887 #ifdef CONFIG_MODIFY_LDT_SYSCALL 2888 struct ldt_struct *ldt; 2889 2890 /* 2891 * If we're not in a valid context with a real (not just lazy) 2892 * user mm, then don't even try. 2893 */ 2894 if (!nmi_uaccess_okay()) 2895 return 0; 2896 2897 /* IRQs are off, so this synchronizes with smp_store_release */ 2898 ldt = smp_load_acquire(¤t->mm->context.ldt); 2899 if (!ldt || idx >= ldt->nr_entries) 2900 return 0; 2901 2902 desc = &ldt->entries[idx]; 2903 #else 2904 return 0; 2905 #endif 2906 } else { 2907 if (idx >= GDT_ENTRIES) 2908 return 0; 2909 2910 desc = raw_cpu_ptr(gdt_page.gdt) + idx; 2911 } 2912 2913 return get_desc_base(desc); 2914 } 2915 2916 #ifdef CONFIG_IA32_EMULATION 2917 2918 #include <linux/compat.h> 2919 2920 static inline int 2921 perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry) 2922 { 2923 /* 32-bit process in 64-bit kernel. */ 2924 unsigned long ss_base, cs_base; 2925 struct stack_frame_ia32 frame; 2926 const struct stack_frame_ia32 __user *fp; 2927 u32 ret_addr; 2928 2929 if (user_64bit_mode(regs)) 2930 return 0; 2931 2932 cs_base = get_segment_base(regs->cs); 2933 ss_base = get_segment_base(regs->ss); 2934 2935 fp = compat_ptr(ss_base + regs->bp); 2936 pagefault_disable(); 2937 2938 /* see perf_callchain_user() below for why we do this */ 2939 if (is_uprobe_at_func_entry(regs) && 2940 !get_user(ret_addr, (const u32 __user *)regs->sp)) 2941 perf_callchain_store(entry, ret_addr); 2942 2943 while (entry->nr < entry->max_stack) { 2944 if (!valid_user_frame(fp, sizeof(frame))) 2945 break; 2946 2947 if (__get_user(frame.next_frame, &fp->next_frame)) 2948 break; 2949 if (__get_user(frame.return_address, &fp->return_address)) 2950 break; 2951 2952 perf_callchain_store(entry, cs_base + frame.return_address); 2953 fp = compat_ptr(ss_base + frame.next_frame); 2954 } 2955 pagefault_enable(); 2956 return 1; 2957 } 2958 #else 2959 static inline int 2960 perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry) 2961 { 2962 return 0; 2963 } 2964 #endif 2965 2966 void 2967 perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) 2968 { 2969 struct stack_frame frame; 2970 const struct stack_frame __user *fp; 2971 unsigned long ret_addr; 2972 2973 if (perf_guest_state()) { 2974 /* TODO: We don't support guest os callchain now */ 2975 return; 2976 } 2977 2978 /* 2979 * We don't know what to do with VM86 stacks.. ignore them for now. 2980 */ 2981 if (regs->flags & (X86_VM_MASK | PERF_EFLAGS_VM)) 2982 return; 2983 2984 fp = (void __user *)regs->bp; 2985 2986 perf_callchain_store(entry, regs->ip); 2987 2988 if (!nmi_uaccess_okay()) 2989 return; 2990 2991 if (perf_callchain_user32(regs, entry)) 2992 return; 2993 2994 pagefault_disable(); 2995 2996 /* 2997 * If we are called from uprobe handler, and we are indeed at the very 2998 * entry to user function (which is normally a `push %rbp` instruction, 2999 * under assumption of application being compiled with frame pointers), 3000 * we should read return address from *regs->sp before proceeding 3001 * to follow frame pointers, otherwise we'll skip immediate caller 3002 * as %rbp is not yet setup. 3003 */ 3004 if (is_uprobe_at_func_entry(regs) && 3005 !get_user(ret_addr, (const unsigned long __user *)regs->sp)) 3006 perf_callchain_store(entry, ret_addr); 3007 3008 while (entry->nr < entry->max_stack) { 3009 if (!valid_user_frame(fp, sizeof(frame))) 3010 break; 3011 3012 if (__get_user(frame.next_frame, &fp->next_frame)) 3013 break; 3014 if (__get_user(frame.return_address, &fp->return_address)) 3015 break; 3016 3017 perf_callchain_store(entry, frame.return_address); 3018 fp = (void __user *)frame.next_frame; 3019 } 3020 pagefault_enable(); 3021 } 3022 3023 /* 3024 * Deal with code segment offsets for the various execution modes: 3025 * 3026 * VM86 - the good olde 16 bit days, where the linear address is 3027 * 20 bits and we use regs->ip + 0x10 * regs->cs. 3028 * 3029 * IA32 - Where we need to look at GDT/LDT segment descriptor tables 3030 * to figure out what the 32bit base address is. 3031 * 3032 * X32 - has TIF_X32 set, but is running in x86_64 3033 * 3034 * X86_64 - CS,DS,SS,ES are all zero based. 3035 */ 3036 static unsigned long code_segment_base(struct pt_regs *regs) 3037 { 3038 /* 3039 * For IA32 we look at the GDT/LDT segment base to convert the 3040 * effective IP to a linear address. 3041 */ 3042 3043 #ifdef CONFIG_X86_32 3044 /* 3045 * If we are in VM86 mode, add the segment offset to convert to a 3046 * linear address. 3047 */ 3048 if (regs->flags & X86_VM_MASK) 3049 return 0x10 * regs->cs; 3050 3051 if (user_mode(regs) && regs->cs != __USER_CS) 3052 return get_segment_base(regs->cs); 3053 #else 3054 if (user_mode(regs) && !user_64bit_mode(regs) && 3055 regs->cs != __USER32_CS) 3056 return get_segment_base(regs->cs); 3057 #endif 3058 return 0; 3059 } 3060 3061 unsigned long perf_arch_instruction_pointer(struct pt_regs *regs) 3062 { 3063 return regs->ip + code_segment_base(regs); 3064 } 3065 3066 static unsigned long common_misc_flags(struct pt_regs *regs) 3067 { 3068 if (regs->flags & PERF_EFLAGS_EXACT) 3069 return PERF_RECORD_MISC_EXACT_IP; 3070 3071 return 0; 3072 } 3073 3074 static unsigned long guest_misc_flags(struct pt_regs *regs) 3075 { 3076 unsigned long guest_state = perf_guest_state(); 3077 3078 if (!(guest_state & PERF_GUEST_ACTIVE)) 3079 return 0; 3080 3081 if (guest_state & PERF_GUEST_USER) 3082 return PERF_RECORD_MISC_GUEST_USER; 3083 else 3084 return PERF_RECORD_MISC_GUEST_KERNEL; 3085 3086 } 3087 3088 static unsigned long host_misc_flags(struct pt_regs *regs) 3089 { 3090 if (user_mode(regs)) 3091 return PERF_RECORD_MISC_USER; 3092 else 3093 return PERF_RECORD_MISC_KERNEL; 3094 } 3095 3096 unsigned long perf_arch_guest_misc_flags(struct pt_regs *regs) 3097 { 3098 unsigned long flags = common_misc_flags(regs); 3099 3100 flags |= guest_misc_flags(regs); 3101 3102 return flags; 3103 } 3104 3105 unsigned long perf_arch_misc_flags(struct pt_regs *regs) 3106 { 3107 unsigned long flags = common_misc_flags(regs); 3108 3109 flags |= host_misc_flags(regs); 3110 3111 return flags; 3112 } 3113 3114 void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap) 3115 { 3116 /* This API doesn't currently support enumerating hybrid PMUs. */ 3117 if (WARN_ON_ONCE(cpu_feature_enabled(X86_FEATURE_HYBRID_CPU)) || 3118 !x86_pmu_initialized()) { 3119 memset(cap, 0, sizeof(*cap)); 3120 return; 3121 } 3122 3123 /* 3124 * Note, hybrid CPU models get tracked as having hybrid PMUs even when 3125 * all E-cores are disabled via BIOS. When E-cores are disabled, the 3126 * base PMU holds the correct number of counters for P-cores. 3127 */ 3128 cap->version = x86_pmu.version; 3129 cap->num_counters_gp = x86_pmu_num_counters(NULL); 3130 cap->num_counters_fixed = x86_pmu_num_counters_fixed(NULL); 3131 cap->bit_width_gp = cap->num_counters_gp ? x86_pmu.cntval_bits : 0; 3132 cap->bit_width_fixed = cap->num_counters_fixed ? x86_pmu.cntval_bits : 0; 3133 cap->events_mask = (unsigned int)x86_pmu.events_maskl; 3134 cap->events_mask_len = x86_pmu.events_mask_len; 3135 cap->pebs_ept = x86_pmu.pebs_ept; 3136 cap->mediated = !!(pmu.capabilities & PERF_PMU_CAP_MEDIATED_VPMU); 3137 } 3138 EXPORT_SYMBOL_FOR_KVM(perf_get_x86_pmu_capability); 3139 3140 u64 perf_get_hw_event_config(int hw_event) 3141 { 3142 int max = x86_pmu.max_events; 3143 3144 if (hw_event < max) 3145 return x86_pmu.event_map(array_index_nospec(hw_event, max)); 3146 3147 return 0; 3148 } 3149 EXPORT_SYMBOL_FOR_KVM(perf_get_hw_event_config); 3150