arch/x86/events/core.c

   1 /*
   2  * Performance events x86 architecture code
   3  *
   4  *  Copyright (C) 2008 Thomas Gleixner <[email protected]>
   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, <[email protected]>
  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/sched/mm.h>
  24 #include <linux/sched/clock.h>
  25 #include <linux/uaccess.h>
  26 #include <linux/slab.h>
  27 #include <linux/cpu.h>
  28 #include <linux/bitops.h>
  29 #include <linux/device.h>
  30 #include <linux/nospec.h>
  31
  32 #include <asm/apic.h>
  33 #include <asm/stacktrace.h>
  34 #include <asm/nmi.h>
  35 #include <asm/smp.h>
  36 #include <asm/alternative.h>
  37 #include <asm/mmu_context.h>
  38 #include <asm/tlbflush.h>
  39 #include <asm/timer.h>
  40 #include <asm/desc.h>
  41 #include <asm/ldt.h>
  42 #include <asm/unwind.h>
  43
  44 #include "perf_event.h"
  45
  46 struct x86_pmu x86_pmu __read_mostly;
  47
  48 DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
  49         .enabled = 1,
  50 };
  51
  52 DEFINE_STATIC_KEY_FALSE(rdpmc_always_available_key);
  53
  54 u64 __read_mostly hw_cache_event_ids
  55                                 [PERF_COUNT_HW_CACHE_MAX]
  56                                 [PERF_COUNT_HW_CACHE_OP_MAX]
  57                                 [PERF_COUNT_HW_CACHE_RESULT_MAX];
  58 u64 __read_mostly hw_cache_extra_regs
  59                                 [PERF_COUNT_HW_CACHE_MAX]
  60                                 [PERF_COUNT_HW_CACHE_OP_MAX]
  61                                 [PERF_COUNT_HW_CACHE_RESULT_MAX];
  62
  63 /*
  64  * Propagate event elapsed time into the generic event.
  65  * Can only be executed on the CPU where the event is active.
  66  * Returns the delta events processed.
  67  */
  68 u64 x86_perf_event_update(struct perf_event *event)
  69 {
  70         struct hw_perf_event *hwc = &event->hw;
  71         int shift = 64 - x86_pmu.cntval_bits;
  72         u64 prev_raw_count, new_raw_count;
  73         int idx = hwc->idx;
  74         u64 delta;
  75
  76         if (idx == INTEL_PMC_IDX_FIXED_BTS)
  77                 return 0;
  78
  79         /*
  80          * Careful: an NMI might modify the previous event value.
  81          *
  82          * Our tactic to handle this is to first atomically read and
  83          * exchange a new raw count - then add that new-prev delta
  84          * count to the generic event atomically:
  85          */
  86 again:
  87         prev_raw_count = local64_read(&hwc->prev_count);
  88         rdpmcl(hwc->event_base_rdpmc, new_raw_count);
  89
  90         if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
  91                                         new_raw_count) != prev_raw_count)
  92                 goto again;
  93
  94         /*
  95          * Now we have the new raw value and have updated the prev
  96          * timestamp already. We can now calculate the elapsed delta
  97          * (event-)time and add that to the generic event.
  98          *
  99          * Careful, not all hw sign-extends above the physical width
 100          * of the count.
 101          */
 102         delta = (new_raw_count << shift) - (prev_raw_count << shift);
 103         delta >>= shift;
 104
 105         local64_add(delta, &event->count);
 106         local64_sub(delta, &hwc->period_left);
 107
 108         return new_raw_count;
 109 }
 110
 111 /*
 112  * Find and validate any extra registers to set up.
 113  */
 114 static int x86_pmu_extra_regs(u64 config, struct perf_event *event)
 115 {
 116         struct hw_perf_event_extra *reg;
 117         struct extra_reg *er;
 118
 119         reg = &event->hw.extra_reg;
 120
 121         if (!x86_pmu.extra_regs)
 122                 return 0;
 123
 124         for (er = x86_pmu.extra_regs; er->msr; er++) {
 125                 if (er->event != (config & er->config_mask))
 126                         continue;
 127                 if (event->attr.config1 & ~er->valid_mask)
 128                         return -EINVAL;
 129                 /* Check if the extra msrs can be safely accessed*/
 130                 if (!er->extra_msr_access)
 131                         return -ENXIO;
 132
 133                 reg->idx = er->idx;
 134                 reg->config = event->attr.config1;
 135                 reg->reg = er->msr;
 136                 break;
 137         }
 138         return 0;
 139 }
 140
 141 static atomic_t active_events;
 142 static atomic_t pmc_refcount;
 143 static DEFINE_MUTEX(pmc_reserve_mutex);
 144
 145 #ifdef CONFIG_X86_LOCAL_APIC
 146
 147 static bool reserve_pmc_hardware(void)
 148 {
 149         int i;
 150
 151         for (i = 0; i < x86_pmu.num_counters; i++) {
 152                 if (!reserve_perfctr_nmi(x86_pmu_event_addr(i)))
 153                         goto perfctr_fail;
 154         }
 155
 156         for (i = 0; i < x86_pmu.num_counters; i++) {
 157                 if (!reserve_evntsel_nmi(x86_pmu_config_addr(i)))
 158                         goto eventsel_fail;
 159         }
 160
 161         return true;
 162
 163 eventsel_fail:
 164         for (i--; i >= 0; i--)
 165                 release_evntsel_nmi(x86_pmu_config_addr(i));
 166
 167         i = x86_pmu.num_counters;
 168
 169 perfctr_fail:
 170         for (i--; i >= 0; i--)
 171                 release_perfctr_nmi(x86_pmu_event_addr(i));
 172
 173         return false;
 174 }
 175
 176 static void release_pmc_hardware(void)
 177 {
 178         int i;
 179
 180         for (i = 0; i < x86_pmu.num_counters; i++) {
 181                 release_perfctr_nmi(x86_pmu_event_addr(i));
 182                 release_evntsel_nmi(x86_pmu_config_addr(i));
 183         }
 184 }
 185
 186 #else
 187
 188 static bool reserve_pmc_hardware(void) { return true; }
 189 static void release_pmc_hardware(void) {}
 190
 191 #endif
 192
 193 static bool check_hw_exists(void)
 194 {
 195         u64 val, val_fail = -1, val_new= ~0;
 196         int i, reg, reg_fail = -1, ret = 0;
 197         int bios_fail = 0;
 198         int reg_safe = -1;
 199
 200         /*
 201          * Check to see if the BIOS enabled any of the counters, if so
 202          * complain and bail.
 203          */
 204         for (i = 0; i < x86_pmu.num_counters; i++) {
 205                 reg = x86_pmu_config_addr(i);
 206                 ret = rdmsrl_safe(reg, &val);
 207                 if (ret)
 208                         goto msr_fail;
 209                 if (val & ARCH_PERFMON_EVENTSEL_ENABLE) {
 210                         bios_fail = 1;
 211                         val_fail = val;
 212                         reg_fail = reg;
 213                 } else {
 214                         reg_safe = i;
 215                 }
 216         }
 217
 218         if (x86_pmu.num_counters_fixed) {
 219                 reg = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
 220                 ret = rdmsrl_safe(reg, &val);
 221                 if (ret)
 222                         goto msr_fail;
 223                 for (i = 0; i < x86_pmu.num_counters_fixed; i++) {
 224                         if (val & (0x03 << i*4)) {
 225                                 bios_fail = 1;
 226                                 val_fail = val;
 227                                 reg_fail = reg;
 228                         }
 229                 }
 230         }
 231
 232         /*
 233          * If all the counters are enabled, the below test will always
 234          * fail.  The tools will also become useless in this scenario.
 235          * Just fail and disable the hardware counters.
 236          */
 237
 238         if (reg_safe == -1) {
 239                 reg = reg_safe;
 240                 goto msr_fail;
 241         }
 242
 243         /*
 244          * Read the current value, change it and read it back to see if it
 245          * matches, this is needed to detect certain hardware emulators
 246          * (qemu/kvm) that don't trap on the MSR access and always return 0s.
 247          */
 248         reg = x86_pmu_event_addr(reg_safe);
 249         if (rdmsrl_safe(reg, &val))
 250                 goto msr_fail;
 251         val ^= 0xffffUL;
 252         ret = wrmsrl_safe(reg, val);
 253         ret |= rdmsrl_safe(reg, &val_new);
 254         if (ret || val != val_new)
 255                 goto msr_fail;
 256
 257         /*
 258          * We still allow the PMU driver to operate:
 259          */
 260         if (bios_fail) {
 261                 pr_cont("Broken BIOS detected, complain to your hardware vendor.\n");
 262                 pr_err(FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n",
 263                               reg_fail, val_fail);
 264         }
 265
 266         return true;
 267
 268 msr_fail:
 269         if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
 270                 pr_cont("PMU not available due to virtualization, using software events only.\n");
 271         } else {
 272                 pr_cont("Broken PMU hardware detected, using software events only.\n");
 273                 pr_err("Failed to access perfctr msr (MSR %x is %Lx)\n",
 274                        reg, val_new);
 275         }
 276
 277         return false;
 278 }
 279
 280 static void hw_perf_event_destroy(struct perf_event *event)
 281 {
 282         x86_release_hardware();
 283         atomic_dec(&active_events);
 284 }
 285
 286 void hw_perf_lbr_event_destroy(struct perf_event *event)
 287 {
 288         hw_perf_event_destroy(event);
 289
 290         /* undo the lbr/bts event accounting */
 291         x86_del_exclusive(x86_lbr_exclusive_lbr);
 292 }
 293
 294 static inline int x86_pmu_initialized(void)
 295 {
 296         return x86_pmu.handle_irq != NULL;
 297 }
 298
 299 static inline int
 300 set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event *event)
 301 {
 302         struct perf_event_attr *attr = &event->attr;
 303         unsigned int cache_type, cache_op, cache_result;
 304         u64 config, val;
 305
 306         config = attr->config;
 307
 308         cache_type = (config >> 0) & 0xff;
 309         if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
 310                 return -EINVAL;
 311         cache_type = array_index_nospec(cache_type, PERF_COUNT_HW_CACHE_MAX);
 312
 313         cache_op = (config >>  8) & 0xff;
 314         if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
 315                 return -EINVAL;
 316         cache_op = array_index_nospec(cache_op, PERF_COUNT_HW_CACHE_OP_MAX);
 317
 318         cache_result = (config >> 16) & 0xff;
 319         if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
 320                 return -EINVAL;
 321         cache_result = array_index_nospec(cache_result, PERF_COUNT_HW_CACHE_RESULT_MAX);
 322
 323         val = hw_cache_event_ids[cache_type][cache_op][cache_result];
 324
 325         if (val == 0)
 326                 return -ENOENT;
 327
 328         if (val == -1)
 329                 return -EINVAL;
 330
 331         hwc->config |= val;
 332         attr->config1 = hw_cache_extra_regs[cache_type][cache_op][cache_result];
 333         return x86_pmu_extra_regs(val, event);
 334 }
 335
 336 int x86_reserve_hardware(void)
 337 {
 338         int err = 0;
 339
 340         if (!atomic_inc_not_zero(&pmc_refcount)) {
 341                 mutex_lock(&pmc_reserve_mutex);
 342                 if (atomic_read(&pmc_refcount) == 0) {
 343                         if (!reserve_pmc_hardware())
 344                                 err = -EBUSY;
 345                         else
 346                                 reserve_ds_buffers();
 347                 }
 348                 if (!err)
 349                         atomic_inc(&pmc_refcount);
 350                 mutex_unlock(&pmc_reserve_mutex);
 351         }
 352
 353         return err;
 354 }
 355
 356 void x86_release_hardware(void)
 357 {
 358         if (atomic_dec_and_mutex_lock(&pmc_refcount, &pmc_reserve_mutex)) {
 359                 release_pmc_hardware();
 360                 release_ds_buffers();
 361                 mutex_unlock(&pmc_reserve_mutex);
 362         }
 363 }
 364
 365 /*
 366  * Check if we can create event of a certain type (that no conflicting events
 367  * are present).
 368  */
 369 int x86_add_exclusive(unsigned int what)
 370 {
 371         int i;
 372
 373         /*
 374          * When lbr_pt_coexist we allow PT to coexist with either LBR or BTS.
 375          * LBR and BTS are still mutually exclusive.
 376          */
 377         if (x86_pmu.lbr_pt_coexist && what == x86_lbr_exclusive_pt)
 378                 return 0;
 379
 380         if (!atomic_inc_not_zero(&x86_pmu.lbr_exclusive[what])) {
 381                 mutex_lock(&pmc_reserve_mutex);
 382                 for (i = 0; i < ARRAY_SIZE(x86_pmu.lbr_exclusive); i++) {
 383                         if (i != what && atomic_read(&x86_pmu.lbr_exclusive[i]))
 384                                 goto fail_unlock;
 385                 }
 386                 atomic_inc(&x86_pmu.lbr_exclusive[what]);
 387                 mutex_unlock(&pmc_reserve_mutex);
 388         }
 389
 390         atomic_inc(&active_events);
 391         return 0;
 392
 393 fail_unlock:
 394         mutex_unlock(&pmc_reserve_mutex);
 395         return -EBUSY;
 396 }
 397
 398 void x86_del_exclusive(unsigned int what)
 399 {
 400         if (x86_pmu.lbr_pt_coexist && what == x86_lbr_exclusive_pt)
 401                 return;
 402
 403         atomic_dec(&x86_pmu.lbr_exclusive[what]);
 404         atomic_dec(&active_events);
 405 }
 406
 407 int x86_setup_perfctr(struct perf_event *event)
 408 {
 409         struct perf_event_attr *attr = &event->attr;
 410         struct hw_perf_event *hwc = &event->hw;
 411         u64 config;
 412
 413         if (!is_sampling_event(event)) {
 414                 hwc->sample_period = x86_pmu.max_period;
 415                 hwc->last_period = hwc->sample_period;
 416                 local64_set(&hwc->period_left, hwc->sample_period);
 417         }
 418
 419         if (attr->type == PERF_TYPE_RAW)
 420                 return x86_pmu_extra_regs(event->attr.config, event);
 421
 422         if (attr->type == PERF_TYPE_HW_CACHE)
 423                 return set_ext_hw_attr(hwc, event);
 424
 425         if (attr->config >= x86_pmu.max_events)
 426                 return -EINVAL;
 427
 428         attr->config = array_index_nospec((unsigned long)attr->config, x86_pmu.max_events);
 429
 430         /*
 431          * The generic map:
 432          */
 433         config = x86_pmu.event_map(attr->config);
 434
 435         if (config == 0)
 436                 return -ENOENT;
 437
 438         if (config == -1LL)
 439                 return -EINVAL;
 440
 441         hwc->config |= config;
 442
 443         return 0;
 444 }
 445
 446 /*
 447  * check that branch_sample_type is compatible with
 448  * settings needed for precise_ip > 1 which implies
 449  * using the LBR to capture ALL taken branches at the
 450  * priv levels of the measurement
 451  */
 452 static inline int precise_br_compat(struct perf_event *event)
 453 {
 454         u64 m = event->attr.branch_sample_type;
 455         u64 b = 0;
 456
 457         /* must capture all branches */
 458         if (!(m & PERF_SAMPLE_BRANCH_ANY))
 459                 return 0;
 460
 461         m &= PERF_SAMPLE_BRANCH_KERNEL | PERF_SAMPLE_BRANCH_USER;
 462
 463         if (!event->attr.exclude_user)
 464                 b |= PERF_SAMPLE_BRANCH_USER;
 465
 466         if (!event->attr.exclude_kernel)
 467                 b |= PERF_SAMPLE_BRANCH_KERNEL;
 468
 469         /*
 470          * ignore PERF_SAMPLE_BRANCH_HV, not supported on x86
 471          */
 472
 473         return m == b;
 474 }
 475
 476 int x86_pmu_max_precise(void)
 477 {
 478         int precise = 0;
 479
 480         /* Support for constant skid */
 481         if (x86_pmu.pebs_active && !x86_pmu.pebs_broken) {
 482                 precise++;
 483
 484                 /* Support for IP fixup */
 485                 if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2)
 486                         precise++;
 487
 488                 if (x86_pmu.pebs_prec_dist)
 489                         precise++;
 490         }
 491         return precise;
 492 }
 493
 494 int x86_pmu_hw_config(struct perf_event *event)
 495 {
 496         if (event->attr.precise_ip) {
 497                 int precise = x86_pmu_max_precise();
 498
 499                 if (event->attr.precise_ip > precise)
 500                         return -EOPNOTSUPP;
 501
 502                 /* There's no sense in having PEBS for non sampling events: */
 503                 if (!is_sampling_event(event))
 504                         return -EINVAL;
 505         }
 506         /*
 507          * check that PEBS LBR correction does not conflict with
 508          * whatever the user is asking with attr->branch_sample_type
 509          */
 510         if (event->attr.precise_ip > 1 && x86_pmu.intel_cap.pebs_format < 2) {
 511                 u64 *br_type = &event->attr.branch_sample_type;
 512
 513                 if (has_branch_stack(event)) {
 514                         if (!precise_br_compat(event))
 515                                 return -EOPNOTSUPP;
 516
 517                         /* branch_sample_type is compatible */
 518
 519                 } else {
 520                         /*
 521                          * user did not specify  branch_sample_type
 522                          *
 523                          * For PEBS fixups, we capture all
 524                          * the branches at the priv level of the
 525                          * event.
 526                          */
 527                         *br_type = PERF_SAMPLE_BRANCH_ANY;
 528
 529                         if (!event->attr.exclude_user)
 530                                 *br_type |= PERF_SAMPLE_BRANCH_USER;
 531
 532                         if (!event->attr.exclude_kernel)
 533                                 *br_type |= PERF_SAMPLE_BRANCH_KERNEL;
 534                 }
 535         }
 536
 537         if (event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK)
 538                 event->attach_state |= PERF_ATTACH_TASK_DATA;
 539
 540         /*
 541          * Generate PMC IRQs:
 542          * (keep 'enabled' bit clear for now)
 543          */
 544         event->hw.config = ARCH_PERFMON_EVENTSEL_INT;
 545
 546         /*
 547          * Count user and OS events unless requested not to
 548          */
 549         if (!event->attr.exclude_user)
 550                 event->hw.config |= ARCH_PERFMON_EVENTSEL_USR;
 551         if (!event->attr.exclude_kernel)
 552                 event->hw.config |= ARCH_PERFMON_EVENTSEL_OS;
 553
 554         if (event->attr.type == PERF_TYPE_RAW)
 555                 event->hw.config |= event->attr.config & X86_RAW_EVENT_MASK;
 556
 557         if (event->attr.sample_period && x86_pmu.limit_period) {
 558                 if (x86_pmu.limit_period(event, event->attr.sample_period) >
 559                                 event->attr.sample_period)
 560                         return -EINVAL;
 561         }
 562
 563         return x86_setup_perfctr(event);
 564 }
 565
 566 /*
 567  * Setup the hardware configuration for a given attr_type
 568  */
 569 static int __x86_pmu_event_init(struct perf_event *event)
 570 {
 571         int err;
 572
 573         if (!x86_pmu_initialized())
 574                 return -ENODEV;
 575
 576         err = x86_reserve_hardware();
 577         if (err)
 578                 return err;
 579
 580         atomic_inc(&active_events);
 581         event->destroy = hw_perf_event_destroy;
 582
 583         event->hw.idx = -1;
 584         event->hw.last_cpu = -1;
 585         event->hw.last_tag = ~0ULL;
 586
 587         /* mark unused */
 588         event->hw.extra_reg.idx = EXTRA_REG_NONE;
 589         event->hw.branch_reg.idx = EXTRA_REG_NONE;
 590
 591         return x86_pmu.hw_config(event);
 592 }
 593
 594 void x86_pmu_disable_all(void)
 595 {
 596         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 597         int idx;
 598
 599         for (idx = 0; idx < x86_pmu.num_counters; idx++) {
 600                 u64 val;
 601
 602                 if (!test_bit(idx, cpuc->active_mask))
 603                         continue;
 604                 rdmsrl(x86_pmu_config_addr(idx), val);
 605                 if (!(val & ARCH_PERFMON_EVENTSEL_ENABLE))
 606                         continue;
 607                 val &= ~ARCH_PERFMON_EVENTSEL_ENABLE;
 608                 wrmsrl(x86_pmu_config_addr(idx), val);
 609         }
 610 }
 611
 612 /*
 613  * There may be PMI landing after enabled=0. The PMI hitting could be before or
 614  * after disable_all.
 615  *
 616  * If PMI hits before disable_all, the PMU will be disabled in the NMI handler.
 617  * It will not be re-enabled in the NMI handler again, because enabled=0. After
 618  * handling the NMI, disable_all will be called, which will not change the
 619  * state either. If PMI hits after disable_all, the PMU is already disabled
 620  * before entering NMI handler. The NMI handler will not change the state
 621  * either.
 622  *
 623  * So either situation is harmless.
 624  */
 625 static void x86_pmu_disable(struct pmu *pmu)
 626 {
 627         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 628
 629         if (!x86_pmu_initialized())
 630                 return;
 631
 632         if (!cpuc->enabled)
 633                 return;
 634
 635         cpuc->n_added = 0;
 636         cpuc->enabled = 0;
 637         barrier();
 638
 639         x86_pmu.disable_all();
 640 }
 641
 642 void x86_pmu_enable_all(int added)
 643 {
 644         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 645         int idx;
 646
 647         for (idx = 0; idx < x86_pmu.num_counters; idx++) {
 648                 struct hw_perf_event *hwc = &cpuc->events[idx]->hw;
 649
 650                 if (!test_bit(idx, cpuc->active_mask))
 651                         continue;
 652
 653                 __x86_pmu_enable_event(hwc, ARCH_PERFMON_EVENTSEL_ENABLE);
 654         }
 655 }
 656
 657 static struct pmu pmu;
 658
 659 static inline int is_x86_event(struct perf_event *event)
 660 {
 661         return event->pmu == &pmu;
 662 }
 663
 664 /*
 665  * Event scheduler state:
 666  *
 667  * Assign events iterating over all events and counters, beginning
 668  * with events with least weights first. Keep the current iterator
 669  * state in struct sched_state.
 670  */
 671 struct sched_state {
 672         int     weight;
 673         int     event;          /* event index */
 674         int     counter;        /* counter index */
 675         int     unassigned;     /* number of events to be assigned left */
 676         int     nr_gp;          /* number of GP counters used */
 677         unsigned long used[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
 678 };
 679
 680 /* Total max is X86_PMC_IDX_MAX, but we are O(n!) limited */
 681 #define SCHED_STATES_MAX        2
 682
 683 struct perf_sched {
 684         int                     max_weight;
 685         int                     max_events;
 686         int                     max_gp;
 687         int                     saved_states;
 688         struct event_constraint **constraints;
 689         struct sched_state      state;
 690         struct sched_state      saved[SCHED_STATES_MAX];
 691 };
 692
 693 /*
 694  * Initialize interator that runs through all events and counters.
 695  */
 696 static void perf_sched_init(struct perf_sched *sched, struct event_constraint **constraints,
 697                             int num, int wmin, int wmax, int gpmax)
 698 {
 699         int idx;
 700
 701         memset(sched, 0, sizeof(*sched));
 702         sched->max_events       = num;
 703         sched->max_weight       = wmax;
 704         sched->max_gp           = gpmax;
 705         sched->constraints      = constraints;
 706
 707         for (idx = 0; idx < num; idx++) {
 708                 if (constraints[idx]->weight == wmin)
 709                         break;
 710         }
 711
 712         sched->state.event      = idx;          /* start with min weight */
 713         sched->state.weight     = wmin;
 714         sched->state.unassigned = num;
 715 }
 716
 717 static void perf_sched_save_state(struct perf_sched *sched)
 718 {
 719         if (WARN_ON_ONCE(sched->saved_states >= SCHED_STATES_MAX))
 720                 return;
 721
 722         sched->saved[sched->saved_states] = sched->state;
 723         sched->saved_states++;
 724 }
 725
 726 static bool perf_sched_restore_state(struct perf_sched *sched)
 727 {
 728         if (!sched->saved_states)
 729                 return false;
 730
 731         sched->saved_states--;
 732         sched->state = sched->saved[sched->saved_states];
 733
 734         /* continue with next counter: */
 735         clear_bit(sched->state.counter++, sched->state.used);
 736
 737         return true;
 738 }
 739
 740 /*
 741  * Select a counter for the current event to schedule. Return true on
 742  * success.
 743  */
 744 static bool __perf_sched_find_counter(struct perf_sched *sched)
 745 {
 746         struct event_constraint *c;
 747         int idx;
 748
 749         if (!sched->state.unassigned)
 750                 return false;
 751
 752         if (sched->state.event >= sched->max_events)
 753                 return false;
 754
 755         c = sched->constraints[sched->state.event];
 756         /* Prefer fixed purpose counters */
 757         if (c->idxmsk64 & (~0ULL << INTEL_PMC_IDX_FIXED)) {
 758                 idx = INTEL_PMC_IDX_FIXED;
 759                 for_each_set_bit_from(idx, c->idxmsk, X86_PMC_IDX_MAX) {
 760                         if (!__test_and_set_bit(idx, sched->state.used))
 761                                 goto done;
 762                 }
 763         }
 764
 765         /* Grab the first unused counter starting with idx */
 766         idx = sched->state.counter;
 767         for_each_set_bit_from(idx, c->idxmsk, INTEL_PMC_IDX_FIXED) {
 768                 if (!__test_and_set_bit(idx, sched->state.used)) {
 769                         if (sched->state.nr_gp++ >= sched->max_gp)
 770                                 return false;
 771
 772                         goto done;
 773                 }
 774         }
 775
 776         return false;
 777
 778 done:
 779         sched->state.counter = idx;
 780
 781         if (c->overlap)
 782                 perf_sched_save_state(sched);
 783
 784         return true;
 785 }
 786
 787 static bool perf_sched_find_counter(struct perf_sched *sched)
 788 {
 789         while (!__perf_sched_find_counter(sched)) {
 790                 if (!perf_sched_restore_state(sched))
 791                         return false;
 792         }
 793
 794         return true;
 795 }
 796
 797 /*
 798  * Go through all unassigned events and find the next one to schedule.
 799  * Take events with the least weight first. Return true on success.
 800  */
 801 static bool perf_sched_next_event(struct perf_sched *sched)
 802 {
 803         struct event_constraint *c;
 804
 805         if (!sched->state.unassigned || !--sched->state.unassigned)
 806                 return false;
 807
 808         do {
 809                 /* next event */
 810                 sched->state.event++;
 811                 if (sched->state.event >= sched->max_events) {
 812                         /* next weight */
 813                         sched->state.event = 0;
 814                         sched->state.weight++;
 815                         if (sched->state.weight > sched->max_weight)
 816                                 return false;
 817                 }
 818                 c = sched->constraints[sched->state.event];
 819         } while (c->weight != sched->state.weight);
 820
 821         sched->state.counter = 0;       /* start with first counter */
 822
 823         return true;
 824 }
 825
 826 /*
 827  * Assign a counter for each event.
 828  */
 829 int perf_assign_events(struct event_constraint **constraints, int n,
 830                         int wmin, int wmax, int gpmax, int *assign)
 831 {
 832         struct perf_sched sched;
 833
 834         perf_sched_init(&sched, constraints, n, wmin, wmax, gpmax);
 835
 836         do {
 837                 if (!perf_sched_find_counter(&sched))
 838                         break;  /* failed */
 839                 if (assign)
 840                         assign[sched.state.event] = sched.state.counter;
 841         } while (perf_sched_next_event(&sched));
 842
 843         return sched.state.unassigned;
 844 }
 845 EXPORT_SYMBOL_GPL(perf_assign_events);
 846
 847 int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 848 {
 849         struct event_constraint *c;
 850         unsigned long used_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
 851         struct perf_event *e;
 852         int i, wmin, wmax, unsched = 0;
 853         struct hw_perf_event *hwc;
 854
 855         bitmap_zero(used_mask, X86_PMC_IDX_MAX);
 856
 857         if (x86_pmu.start_scheduling)
 858                 x86_pmu.start_scheduling(cpuc);
 859
 860         for (i = 0, wmin = X86_PMC_IDX_MAX, wmax = 0; i < n; i++) {
 861                 cpuc->event_constraint[i] = NULL;
 862                 c = x86_pmu.get_event_constraints(cpuc, i, cpuc->event_list[i]);
 863                 cpuc->event_constraint[i] = c;
 864
 865                 wmin = min(wmin, c->weight);
 866                 wmax = max(wmax, c->weight);
 867         }
 868
 869         /*
 870          * fastpath, try to reuse previous register
 871          */
 872         for (i = 0; i < n; i++) {
 873                 hwc = &cpuc->event_list[i]->hw;
 874                 c = cpuc->event_constraint[i];
 875
 876                 /* never assigned */
 877                 if (hwc->idx == -1)
 878                         break;
 879
 880                 /* constraint still honored */
 881                 if (!test_bit(hwc->idx, c->idxmsk))
 882                         break;
 883
 884                 /* not already used */
 885                 if (test_bit(hwc->idx, used_mask))
 886                         break;
 887
 888                 __set_bit(hwc->idx, used_mask);
 889                 if (assign)
 890                         assign[i] = hwc->idx;
 891         }
 892
 893         /* slow path */
 894         if (i != n) {
 895                 int gpmax = x86_pmu.num_counters;
 896
 897                 /*
 898                  * Do not allow scheduling of more than half the available
 899                  * generic counters.
 900                  *
 901                  * This helps avoid counter starvation of sibling thread by
 902                  * ensuring at most half the counters cannot be in exclusive
 903                  * mode. There is no designated counters for the limits. Any
 904                  * N/2 counters can be used. This helps with events with
 905                  * specific counter constraints.
 906                  */
 907                 if (is_ht_workaround_enabled() && !cpuc->is_fake &&
 908                     READ_ONCE(cpuc->excl_cntrs->exclusive_present))
 909                         gpmax /= 2;
 910
 911                 unsched = perf_assign_events(cpuc->event_constraint, n, wmin,
 912                                              wmax, gpmax, assign);
 913         }
 914
 915         /*
 916          * In case of success (unsched = 0), mark events as committed,
 917          * so we do not put_constraint() in case new events are added
 918          * and fail to be scheduled
 919          *
 920          * We invoke the lower level commit callback to lock the resource
 921          *
 922          * We do not need to do all of this in case we are called to
 923          * validate an event group (assign == NULL)
 924          */
 925         if (!unsched && assign) {
 926                 for (i = 0; i < n; i++) {
 927                         e = cpuc->event_list[i];
 928                         e->hw.flags |= PERF_X86_EVENT_COMMITTED;
 929                         if (x86_pmu.commit_scheduling)
 930                                 x86_pmu.commit_scheduling(cpuc, i, assign[i]);
 931                 }
 932         } else {
 933                 for (i = 0; i < n; i++) {
 934                         e = cpuc->event_list[i];
 935                         /*
 936                          * do not put_constraint() on comitted events,
 937                          * because they are good to go
 938                          */
 939                         if ((e->hw.flags & PERF_X86_EVENT_COMMITTED))
 940                                 continue;
 941
 942                         /*
 943                          * release events that failed scheduling
 944                          */
 945                         if (x86_pmu.put_event_constraints)
 946                                 x86_pmu.put_event_constraints(cpuc, e);
 947                 }
 948         }
 949
 950         if (x86_pmu.stop_scheduling)
 951                 x86_pmu.stop_scheduling(cpuc);
 952
 953         return unsched ? -EINVAL : 0;
 954 }
 955
 956 /*
 957  * dogrp: true if must collect siblings events (group)
 958  * returns total number of events and error code
 959  */
 960 static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader, bool dogrp)
 961 {
 962         struct perf_event *event;
 963         int n, max_count;
 964
 965         max_count = x86_pmu.num_counters + x86_pmu.num_counters_fixed;
 966
 967         /* current number of events already accepted */
 968         n = cpuc->n_events;
 969
 970         if (is_x86_event(leader)) {
 971                 if (n >= max_count)
 972                         return -EINVAL;
 973                 cpuc->event_list[n] = leader;
 974                 n++;
 975         }
 976         if (!dogrp)
 977                 return n;
 978
 979         for_each_sibling_event(event, leader) {
 980                 if (!is_x86_event(event) ||
 981                     event->state <= PERF_EVENT_STATE_OFF)
 982                         continue;
 983
 984                 if (n >= max_count)
 985                         return -EINVAL;
 986
 987                 cpuc->event_list[n] = event;
 988                 n++;
 989         }
 990         return n;
 991 }
 992
 993 static inline void x86_assign_hw_event(struct perf_event *event,
 994                                 struct cpu_hw_events *cpuc, int i)
 995 {
 996         struct hw_perf_event *hwc = &event->hw;
 997
 998         hwc->idx = cpuc->assign[i];
 999         hwc->last_cpu = smp_processor_id();
1000         hwc->last_tag = ++cpuc->tags[i];
1001
1002         if (hwc->idx == INTEL_PMC_IDX_FIXED_BTS) {
1003                 hwc->config_base = 0;
1004                 hwc->event_base = 0;
1005         } else if (hwc->idx >= INTEL_PMC_IDX_FIXED) {
1006                 hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
1007                 hwc->event_base = MSR_ARCH_PERFMON_FIXED_CTR0 + (hwc->idx - INTEL_PMC_IDX_FIXED);
1008                 hwc->event_base_rdpmc = (hwc->idx - INTEL_PMC_IDX_FIXED) | 1<<30;
1009         } else {
1010                 hwc->config_base = x86_pmu_config_addr(hwc->idx);
1011                 hwc->event_base  = x86_pmu_event_addr(hwc->idx);
1012                 hwc->event_base_rdpmc = x86_pmu_rdpmc_index(hwc->idx);
1013         }
1014 }
1015
1016 /**
1017  * x86_perf_rdpmc_index - Return PMC counter used for event
1018  * @event: the perf_event to which the PMC counter was assigned
1019  *
1020  * The counter assigned to this performance event may change if interrupts
1021  * are enabled. This counter should thus never be used while interrupts are
1022  * enabled. Before this function is used to obtain the assigned counter the
1023  * event should be checked for validity using, for example,
1024  * perf_event_read_local(), within the same interrupt disabled section in
1025  * which this counter is planned to be used.
1026  *
1027  * Return: The index of the performance monitoring counter assigned to
1028  * @perf_event.
1029  */
1030 int x86_perf_rdpmc_index(struct perf_event *event)
1031 {
1032         lockdep_assert_irqs_disabled();
1033
1034         return event->hw.event_base_rdpmc;
1035 }
1036
1037 static inline int match_prev_assignment(struct hw_perf_event *hwc,
1038                                         struct cpu_hw_events *cpuc,
1039                                         int i)
1040 {
1041         return hwc->idx == cpuc->assign[i] &&
1042                 hwc->last_cpu == smp_processor_id() &&
1043                 hwc->last_tag == cpuc->tags[i];
1044 }
1045
1046 static void x86_pmu_start(struct perf_event *event, int flags);
1047
1048 static void x86_pmu_enable(struct pmu *pmu)
1049 {
1050         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1051         struct perf_event *event;
1052         struct hw_perf_event *hwc;
1053         int i, added = cpuc->n_added;
1054
1055         if (!x86_pmu_initialized())
1056                 return;
1057
1058         if (cpuc->enabled)
1059                 return;
1060
1061         if (cpuc->n_added) {
1062                 int n_running = cpuc->n_events - cpuc->n_added;
1063                 /*
1064                  * apply assignment obtained either from
1065                  * hw_perf_group_sched_in() or x86_pmu_enable()
1066                  *
1067                  * step1: save events moving to new counters
1068                  */
1069                 for (i = 0; i < n_running; i++) {
1070                         event = cpuc->event_list[i];
1071                         hwc = &event->hw;
1072
1073                         /*
1074                          * we can avoid reprogramming counter if:
1075                          * - assigned same counter as last time
1076                          * - running on same CPU as last time
1077                          * - no other event has used the counter since
1078                          */
1079                         if (hwc->idx == -1 ||
1080                             match_prev_assignment(hwc, cpuc, i))
1081                                 continue;
1082
1083                         /*
1084                          * Ensure we don't accidentally enable a stopped
1085                          * counter simply because we rescheduled.
1086                          */
1087                         if (hwc->state & PERF_HES_STOPPED)
1088                                 hwc->state |= PERF_HES_ARCH;
1089
1090                         x86_pmu_stop(event, PERF_EF_UPDATE);
1091                 }
1092
1093                 /*
1094                  * step2: reprogram moved events into new counters
1095                  */
1096                 for (i = 0; i < cpuc->n_events; i++) {
1097                         event = cpuc->event_list[i];
1098                         hwc = &event->hw;
1099
1100                         if (!match_prev_assignment(hwc, cpuc, i))
1101                                 x86_assign_hw_event(event, cpuc, i);
1102                         else if (i < n_running)
1103                                 continue;
1104
1105                         if (hwc->state & PERF_HES_ARCH)
1106                                 continue;
1107
1108                         x86_pmu_start(event, PERF_EF_RELOAD);
1109                 }
1110                 cpuc->n_added = 0;
1111                 perf_events_lapic_init();
1112         }
1113
1114         cpuc->enabled = 1;
1115         barrier();
1116
1117         x86_pmu.enable_all(added);
1118 }
1119
1120 static DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left);
1121
1122 /*
1123  * Set the next IRQ period, based on the hwc->period_left value.
1124  * To be called with the event disabled in hw:
1125  */
1126 int x86_perf_event_set_period(struct perf_event *event)
1127 {
1128         struct hw_perf_event *hwc = &event->hw;
1129         s64 left = local64_read(&hwc->period_left);
1130         s64 period = hwc->sample_period;
1131         int ret = 0, idx = hwc->idx;
1132
1133         if (idx == INTEL_PMC_IDX_FIXED_BTS)
1134                 return 0;
1135
1136         /*
1137          * If we are way outside a reasonable range then just skip forward:
1138          */
1139         if (unlikely(left <= -period)) {
1140                 left = period;
1141                 local64_set(&hwc->period_left, left);
1142                 hwc->last_period = period;
1143                 ret = 1;
1144         }
1145
1146         if (unlikely(left <= 0)) {
1147                 left += period;
1148                 local64_set(&hwc->period_left, left);
1149                 hwc->last_period = period;
1150                 ret = 1;
1151         }
1152         /*
1153          * Quirk: certain CPUs dont like it if just 1 hw_event is left:
1154          */
1155         if (unlikely(left < 2))
1156                 left = 2;
1157
1158         if (left > x86_pmu.max_period)
1159                 left = x86_pmu.max_period;
1160
1161         if (x86_pmu.limit_period)
1162                 left = x86_pmu.limit_period(event, left);
1163
1164         per_cpu(pmc_prev_left[idx], smp_processor_id()) = left;
1165
1166         /*
1167          * The hw event starts counting from this event offset,
1168          * mark it to be able to extra future deltas:
1169          */
1170         local64_set(&hwc->prev_count, (u64)-left);
1171
1172         wrmsrl(hwc->event_base, (u64)(-left) & x86_pmu.cntval_mask);
1173
1174         /*
1175          * Due to erratum on certan cpu we need
1176          * a second write to be sure the register
1177          * is updated properly
1178          */
1179         if (x86_pmu.perfctr_second_write) {
1180                 wrmsrl(hwc->event_base,
1181                         (u64)(-left) & x86_pmu.cntval_mask);
1182         }
1183
1184         perf_event_update_userpage(event);
1185
1186         return ret;
1187 }
1188
1189 void x86_pmu_enable_event(struct perf_event *event)
1190 {
1191         if (__this_cpu_read(cpu_hw_events.enabled))
1192                 __x86_pmu_enable_event(&event->hw,
1193                                        ARCH_PERFMON_EVENTSEL_ENABLE);
1194 }
1195
1196 /*
1197  * Add a single event to the PMU.
1198  *
1199  * The event is added to the group of enabled events
1200  * but only if it can be scehduled with existing events.
1201  */
1202 static int x86_pmu_add(struct perf_event *event, int flags)
1203 {
1204         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1205         struct hw_perf_event *hwc;
1206         int assign[X86_PMC_IDX_MAX];
1207         int n, n0, ret;
1208
1209         hwc = &event->hw;
1210
1211         n0 = cpuc->n_events;
1212         ret = n = collect_events(cpuc, event, false);
1213         if (ret < 0)
1214                 goto out;
1215
1216         hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
1217         if (!(flags & PERF_EF_START))
1218                 hwc->state |= PERF_HES_ARCH;
1219
1220         /*
1221          * If group events scheduling transaction was started,
1222          * skip the schedulability test here, it will be performed
1223          * at commit time (->commit_txn) as a whole.
1224          *
1225          * If commit fails, we'll call ->del() on all events
1226          * for which ->add() was called.
1227          */
1228         if (cpuc->txn_flags & PERF_PMU_TXN_ADD)
1229                 goto done_collect;
1230
1231         ret = x86_pmu.schedule_events(cpuc, n, assign);
1232         if (ret)
1233                 goto out;
1234         /*
1235          * copy new assignment, now we know it is possible
1236          * will be used by hw_perf_enable()
1237          */
1238         memcpy(cpuc->assign, assign, n*sizeof(int));
1239
1240 done_collect:
1241         /*
1242          * Commit the collect_events() state. See x86_pmu_del() and
1243          * x86_pmu_*_txn().
1244          */
1245         cpuc->n_events = n;
1246         cpuc->n_added += n - n0;
1247         cpuc->n_txn += n - n0;
1248
1249         if (x86_pmu.add) {
1250                 /*
1251                  * This is before x86_pmu_enable() will call x86_pmu_start(),
1252                  * so we enable LBRs before an event needs them etc..
1253                  */
1254                 x86_pmu.add(event);
1255         }
1256
1257         ret = 0;
1258 out:
1259         return ret;
1260 }
1261
1262 static void x86_pmu_start(struct perf_event *event, int flags)
1263 {
1264         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1265         int idx = event->hw.idx;
1266
1267         if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
1268                 return;
1269
1270         if (WARN_ON_ONCE(idx == -1))
1271                 return;
1272
1273         if (flags & PERF_EF_RELOAD) {
1274                 WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
1275                 x86_perf_event_set_period(event);
1276         }
1277
1278         event->hw.state = 0;
1279
1280         cpuc->events[idx] = event;
1281         __set_bit(idx, cpuc->active_mask);
1282         __set_bit(idx, cpuc->running);
1283         x86_pmu.enable(event);
1284         perf_event_update_userpage(event);
1285 }
1286
1287 void perf_event_print_debug(void)
1288 {
1289         u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
1290         u64 pebs, debugctl;
1291         struct cpu_hw_events *cpuc;
1292         unsigned long flags;
1293         int cpu, idx;
1294
1295         if (!x86_pmu.num_counters)
1296                 return;
1297
1298         local_irq_save(flags);
1299
1300         cpu = smp_processor_id();
1301         cpuc = &per_cpu(cpu_hw_events, cpu);
1302
1303         if (x86_pmu.version >= 2) {
1304                 rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
1305                 rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
1306                 rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow);
1307                 rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed);
1308
1309                 pr_info("\n");
1310                 pr_info("CPU#%d: ctrl:       %016llx\n", cpu, ctrl);
1311                 pr_info("CPU#%d: status:     %016llx\n", cpu, status);
1312                 pr_info("CPU#%d: overflow:   %016llx\n", cpu, overflow);
1313                 pr_info("CPU#%d: fixed:      %016llx\n", cpu, fixed);
1314                 if (x86_pmu.pebs_constraints) {
1315                         rdmsrl(MSR_IA32_PEBS_ENABLE, pebs);
1316                         pr_info("CPU#%d: pebs:       %016llx\n", cpu, pebs);
1317                 }
1318                 if (x86_pmu.lbr_nr) {
1319                         rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
1320                         pr_info("CPU#%d: debugctl:   %016llx\n", cpu, debugctl);
1321                 }
1322         }
1323         pr_info("CPU#%d: active:     %016llx\n", cpu, *(u64 *)cpuc->active_mask);
1324
1325         for (idx = 0; idx < x86_pmu.num_counters; idx++) {
1326                 rdmsrl(x86_pmu_config_addr(idx), pmc_ctrl);
1327                 rdmsrl(x86_pmu_event_addr(idx), pmc_count);
1328
1329                 prev_left = per_cpu(pmc_prev_left[idx], cpu);
1330
1331                 pr_info("CPU#%d:   gen-PMC%d ctrl:  %016llx\n",
1332                         cpu, idx, pmc_ctrl);
1333                 pr_info("CPU#%d:   gen-PMC%d count: %016llx\n",
1334                         cpu, idx, pmc_count);
1335                 pr_info("CPU#%d:   gen-PMC%d left:  %016llx\n",
1336                         cpu, idx, prev_left);
1337         }
1338         for (idx = 0; idx < x86_pmu.num_counters_fixed; idx++) {
1339                 rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR0 + idx, pmc_count);
1340
1341                 pr_info("CPU#%d: fixed-PMC%d count: %016llx\n",
1342                         cpu, idx, pmc_count);
1343         }
1344         local_irq_restore(flags);
1345 }
1346
1347 void x86_pmu_stop(struct perf_event *event, int flags)
1348 {
1349         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1350         struct hw_perf_event *hwc = &event->hw;
1351
1352         if (__test_and_clear_bit(hwc->idx, cpuc->active_mask)) {
1353                 x86_pmu.disable(event);
1354                 cpuc->events[hwc->idx] = NULL;
1355                 WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
1356                 hwc->state |= PERF_HES_STOPPED;
1357         }
1358
1359         if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
1360                 /*
1361                  * Drain the remaining delta count out of a event
1362                  * that we are disabling:
1363                  */
1364                 x86_perf_event_update(event);
1365                 hwc->state |= PERF_HES_UPTODATE;
1366         }
1367 }
1368
1369 static void x86_pmu_del(struct perf_event *event, int flags)
1370 {
1371         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1372         int i;
1373
1374         /*
1375          * event is descheduled
1376          */
1377         event->hw.flags &= ~PERF_X86_EVENT_COMMITTED;
1378
1379         /*
1380          * If we're called during a txn, we only need to undo x86_pmu.add.
1381          * The events never got scheduled and ->cancel_txn will truncate
1382          * the event_list.
1383          *
1384          * XXX assumes any ->del() called during a TXN will only be on
1385          * an event added during that same TXN.
1386          */
1387         if (cpuc->txn_flags & PERF_PMU_TXN_ADD)
1388                 goto do_del;
1389
1390         /*
1391          * Not a TXN, therefore cleanup properly.
1392          */
1393         x86_pmu_stop(event, PERF_EF_UPDATE);
1394
1395         for (i = 0; i < cpuc->n_events; i++) {
1396                 if (event == cpuc->event_list[i])
1397                         break;
1398         }
1399
1400         if (WARN_ON_ONCE(i == cpuc->n_events)) /* called ->del() without ->add() ? */
1401                 return;
1402
1403         /* If we have a newly added event; make sure to decrease n_added. */
1404         if (i >= cpuc->n_events - cpuc->n_added)
1405                 --cpuc->n_added;
1406
1407         if (x86_pmu.put_event_constraints)
1408                 x86_pmu.put_event_constraints(cpuc, event);
1409
1410         /* Delete the array entry. */
1411         while (++i < cpuc->n_events) {
1412                 cpuc->event_list[i-1] = cpuc->event_list[i];
1413                 cpuc->event_constraint[i-1] = cpuc->event_constraint[i];
1414         }
1415         --cpuc->n_events;
1416
1417         perf_event_update_userpage(event);
1418
1419 do_del:
1420         if (x86_pmu.del) {
1421                 /*
1422                  * This is after x86_pmu_stop(); so we disable LBRs after any
1423                  * event can need them etc..
1424                  */
1425                 x86_pmu.del(event);
1426         }
1427 }
1428
1429 int x86_pmu_handle_irq(struct pt_regs *regs)
1430 {
1431         struct perf_sample_data data;
1432         struct cpu_hw_events *cpuc;
1433         struct perf_event *event;
1434         int idx, handled = 0;
1435         u64 val;
1436
1437         cpuc = this_cpu_ptr(&cpu_hw_events);
1438
1439         /*
1440          * Some chipsets need to unmask the LVTPC in a particular spot
1441          * inside the nmi handler.  As a result, the unmasking was pushed
1442          * into all the nmi handlers.
1443          *
1444          * This generic handler doesn't seem to have any issues where the
1445          * unmasking occurs so it was left at the top.
1446          */
1447         apic_write(APIC_LVTPC, APIC_DM_NMI);
1448
1449         for (idx = 0; idx < x86_pmu.num_counters; idx++) {
1450                 if (!test_bit(idx, cpuc->active_mask)) {
1451                         /*
1452                          * Though we deactivated the counter some cpus
1453                          * might still deliver spurious interrupts still
1454                          * in flight. Catch them:
1455                          */
1456                         if (__test_and_clear_bit(idx, cpuc->running))
1457                                 handled++;
1458                         continue;
1459                 }
1460
1461                 event = cpuc->events[idx];
1462
1463                 val = x86_perf_event_update(event);
1464                 if (val & (1ULL << (x86_pmu.cntval_bits - 1)))
1465                         continue;
1466
1467                 /*
1468                  * event overflow
1469                  */
1470                 handled++;
1471                 perf_sample_data_init(&data, 0, event->hw.last_period);
1472
1473                 if (!x86_perf_event_set_period(event))
1474                         continue;
1475
1476                 if (perf_event_overflow(event, &data, regs))
1477                         x86_pmu_stop(event, 0);
1478         }
1479
1480         if (handled)
1481                 inc_irq_stat(apic_perf_irqs);
1482
1483         return handled;
1484 }
1485
1486 void perf_events_lapic_init(void)
1487 {
1488         if (!x86_pmu.apic || !x86_pmu_initialized())
1489                 return;
1490
1491         /*
1492          * Always use NMI for PMU
1493          */
1494         apic_write(APIC_LVTPC, APIC_DM_NMI);
1495 }
1496
1497 static int
1498 perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs)
1499 {
1500         u64 start_clock;
1501         u64 finish_clock;
1502         int ret;
1503
1504         /*
1505          * All PMUs/events that share this PMI handler should make sure to
1506          * increment active_events for their events.
1507          */
1508         if (!atomic_read(&active_events))
1509                 return NMI_DONE;
1510
1511         start_clock = sched_clock();
1512         ret = x86_pmu.handle_irq(regs);
1513         finish_clock = sched_clock();
1514
1515         perf_sample_event_took(finish_clock - start_clock);
1516
1517         return ret;
1518 }
1519 NOKPROBE_SYMBOL(perf_event_nmi_handler);
1520
1521 struct event_constraint emptyconstraint;
1522 struct event_constraint unconstrained;
1523
1524 static int x86_pmu_prepare_cpu(unsigned int cpu)
1525 {
1526         struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
1527         int i;
1528
1529         for (i = 0 ; i < X86_PERF_KFREE_MAX; i++)
1530                 cpuc->kfree_on_online[i] = NULL;
1531         if (x86_pmu.cpu_prepare)
1532                 return x86_pmu.cpu_prepare(cpu);
1533         return 0;
1534 }
1535
1536 static int x86_pmu_dead_cpu(unsigned int cpu)
1537 {
1538         if (x86_pmu.cpu_dead)
1539                 x86_pmu.cpu_dead(cpu);
1540         return 0;
1541 }
1542
1543 static int x86_pmu_online_cpu(unsigned int cpu)
1544 {
1545         struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
1546         int i;
1547
1548         for (i = 0 ; i < X86_PERF_KFREE_MAX; i++) {
1549                 kfree(cpuc->kfree_on_online[i]);
1550                 cpuc->kfree_on_online[i] = NULL;
1551         }
1552         return 0;
1553 }
1554
1555 static int x86_pmu_starting_cpu(unsigned int cpu)
1556 {
1557         if (x86_pmu.cpu_starting)
1558                 x86_pmu.cpu_starting(cpu);
1559         return 0;
1560 }
1561
1562 static int x86_pmu_dying_cpu(unsigned int cpu)
1563 {
1564         if (x86_pmu.cpu_dying)
1565                 x86_pmu.cpu_dying(cpu);
1566         return 0;
1567 }
1568
1569 static void __init pmu_check_apic(void)
1570 {
1571         if (boot_cpu_has(X86_FEATURE_APIC))
1572                 return;
1573
1574         x86_pmu.apic = 0;
1575         pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n");
1576         pr_info("no hardware sampling interrupt available.\n");
1577
1578         /*
1579          * If we have a PMU initialized but no APIC
1580          * interrupts, we cannot sample hardware
1581          * events (user-space has to fall back and
1582          * sample via a hrtimer based software event):
1583          */
1584         pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
1585
1586 }
1587
1588 static struct attribute_group x86_pmu_format_group __ro_after_init = {
1589         .name = "format",
1590         .attrs = NULL,
1591 };
1592
1593 /*
1594  * Remove all undefined events (x86_pmu.event_map(id) == 0)
1595  * out of events_attr attributes.
1596  */
1597 static void __init filter_events(struct attribute **attrs)
1598 {
1599         struct device_attribute *d;
1600         struct perf_pmu_events_attr *pmu_attr;
1601         int offset = 0;
1602         int i, j;
1603
1604         for (i = 0; attrs[i]; i++) {
1605                 d = (struct device_attribute *)attrs[i];
1606                 pmu_attr = container_of(d, struct perf_pmu_events_attr, attr);
1607                 /* str trumps id */
1608                 if (pmu_attr->event_str)
1609                         continue;
1610                 if (x86_pmu.event_map(i + offset))
1611                         continue;
1612
1613                 for (j = i; attrs[j]; j++)
1614                         attrs[j] = attrs[j + 1];
1615
1616                 /* Check the shifted attr. */
1617                 i--;
1618
1619                 /*
1620                  * event_map() is index based, the attrs array is organized
1621                  * by increasing event index. If we shift the events, then
1622                  * we need to compensate for the event_map(), otherwise
1623                  * we are looking up the wrong event in the map
1624                  */
1625                 offset++;
1626         }
1627 }
1628
1629 /* Merge two pointer arrays */
1630 __init struct attribute **merge_attr(struct attribute **a, struct attribute **b)
1631 {
1632         struct attribute **new;
1633         int j, i;
1634
1635         for (j = 0; a && a[j]; j++)
1636                 ;
1637         for (i = 0; b && b[i]; i++)
1638                 j++;
1639         j++;
1640
1641         new = kmalloc_array(j, sizeof(struct attribute *), GFP_KERNEL);
1642         if (!new)
1643                 return NULL;
1644
1645         j = 0;
1646         for (i = 0; a && a[i]; i++)
1647                 new[j++] = a[i];
1648         for (i = 0; b && b[i]; i++)
1649                 new[j++] = b[i];
1650         new[j] = NULL;
1651
1652         return new;
1653 }
1654
1655 ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr, char *page)
1656 {
1657         struct perf_pmu_events_attr *pmu_attr = \
1658                 container_of(attr, struct perf_pmu_events_attr, attr);
1659         u64 config = x86_pmu.event_map(pmu_attr->id);
1660
1661         /* string trumps id */
1662         if (pmu_attr->event_str)
1663                 return sprintf(page, "%s", pmu_attr->event_str);
1664
1665         return x86_pmu.events_sysfs_show(page, config);
1666 }
1667 EXPORT_SYMBOL_GPL(events_sysfs_show);
1668
1669 ssize_t events_ht_sysfs_show(struct device *dev, struct device_attribute *attr,
1670                           char *page)
1671 {
1672         struct perf_pmu_events_ht_attr *pmu_attr =
1673                 container_of(attr, struct perf_pmu_events_ht_attr, attr);
1674
1675         /*
1676          * Report conditional events depending on Hyper-Threading.
1677          *
1678          * This is overly conservative as usually the HT special
1679          * handling is not needed if the other CPU thread is idle.
1680          *
1681          * Note this does not (and cannot) handle the case when thread
1682          * siblings are invisible, for example with virtualization
1683          * if they are owned by some other guest.  The user tool
1684          * has to re-read when a thread sibling gets onlined later.
1685          */
1686         return sprintf(page, "%s",
1687                         topology_max_smt_threads() > 1 ?
1688                         pmu_attr->event_str_ht :
1689                         pmu_attr->event_str_noht);
1690 }
1691
1692 EVENT_ATTR(cpu-cycles,                  CPU_CYCLES              );
1693 EVENT_ATTR(instructions,                INSTRUCTIONS            );
1694 EVENT_ATTR(cache-references,            CACHE_REFERENCES        );
1695 EVENT_ATTR(cache-misses,                CACHE_MISSES            );
1696 EVENT_ATTR(branch-instructions,         BRANCH_INSTRUCTIONS     );
1697 EVENT_ATTR(branch-misses,               BRANCH_MISSES           );
1698 EVENT_ATTR(bus-cycles,                  BUS_CYCLES              );
1699 EVENT_ATTR(stalled-cycles-frontend,     STALLED_CYCLES_FRONTEND );
1700 EVENT_ATTR(stalled-cycles-backend,      STALLED_CYCLES_BACKEND  );
1701 EVENT_ATTR(ref-cycles,                  REF_CPU_CYCLES          );
1702
1703 static struct attribute *empty_attrs;
1704
1705 static struct attribute *events_attr[] = {
1706         EVENT_PTR(CPU_CYCLES),
1707         EVENT_PTR(INSTRUCTIONS),
1708         EVENT_PTR(CACHE_REFERENCES),
1709         EVENT_PTR(CACHE_MISSES),
1710         EVENT_PTR(BRANCH_INSTRUCTIONS),
1711         EVENT_PTR(BRANCH_MISSES),
1712         EVENT_PTR(BUS_CYCLES),
1713         EVENT_PTR(STALLED_CYCLES_FRONTEND),
1714         EVENT_PTR(STALLED_CYCLES_BACKEND),
1715         EVENT_PTR(REF_CPU_CYCLES),
1716         NULL,
1717 };
1718
1719 static struct attribute_group x86_pmu_events_group __ro_after_init = {
1720         .name = "events",
1721         .attrs = events_attr,
1722 };
1723
1724 ssize_t x86_event_sysfs_show(char *page, u64 config, u64 event)
1725 {
1726         u64 umask  = (config & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
1727         u64 cmask  = (config & ARCH_PERFMON_EVENTSEL_CMASK) >> 24;
1728         bool edge  = (config & ARCH_PERFMON_EVENTSEL_EDGE);
1729         bool pc    = (config & ARCH_PERFMON_EVENTSEL_PIN_CONTROL);
1730         bool any   = (config & ARCH_PERFMON_EVENTSEL_ANY);
1731         bool inv   = (config & ARCH_PERFMON_EVENTSEL_INV);
1732         ssize_t ret;
1733
1734         /*
1735         * We have whole page size to spend and just little data
1736         * to write, so we can safely use sprintf.
1737         */
1738         ret = sprintf(page, "event=0x%02llx", event);
1739
1740         if (umask)
1741                 ret += sprintf(page + ret, ",umask=0x%02llx", umask);
1742
1743         if (edge)
1744                 ret += sprintf(page + ret, ",edge");
1745
1746         if (pc)
1747                 ret += sprintf(page + ret, ",pc");
1748
1749         if (any)
1750                 ret += sprintf(page + ret, ",any");
1751
1752         if (inv)
1753                 ret += sprintf(page + ret, ",inv");
1754
1755         if (cmask)
1756                 ret += sprintf(page + ret, ",cmask=0x%02llx", cmask);
1757
1758         ret += sprintf(page + ret, "\n");
1759
1760         return ret;
1761 }
1762
1763 static struct attribute_group x86_pmu_attr_group;
1764 static struct attribute_group x86_pmu_caps_group;
1765
1766 static int __init init_hw_perf_events(void)
1767 {
1768         struct x86_pmu_quirk *quirk;
1769         int err;
1770
1771         pr_info("Performance Events: ");
1772
1773         switch (boot_cpu_data.x86_vendor) {
1774         case X86_VENDOR_INTEL:
1775                 err = intel_pmu_init();
1776                 break;
1777         case X86_VENDOR_AMD:
1778                 err = amd_pmu_init();
1779                 break;
1780         case X86_VENDOR_HYGON:
1781                 err = amd_pmu_init();
1782                 x86_pmu.name = "HYGON";
1783                 break;
1784         default:
1785                 err = -ENOTSUPP;
1786         }
1787         if (err != 0) {
1788                 pr_cont("no PMU driver, software events only.\n");
1789                 return 0;
1790         }
1791
1792         pmu_check_apic();
1793
1794         /* sanity check that the hardware exists or is emulated */
1795         if (!check_hw_exists())
1796                 return 0;
1797
1798         pr_cont("%s PMU driver.\n", x86_pmu.name);
1799
1800         x86_pmu.attr_rdpmc = 1; /* enable userspace RDPMC usage by default */
1801
1802         for (quirk = x86_pmu.quirks; quirk; quirk = quirk->next)
1803                 quirk->func();
1804
1805         if (!x86_pmu.intel_ctrl)
1806                 x86_pmu.intel_ctrl = (1 << x86_pmu.num_counters) - 1;
1807
1808         perf_events_lapic_init();
1809         register_nmi_handler(NMI_LOCAL, perf_event_nmi_handler, 0, "PMI");
1810
1811         unconstrained = (struct event_constraint)
1812                 __EVENT_CONSTRAINT(0, (1ULL << x86_pmu.num_counters) - 1,
1813                                    0, x86_pmu.num_counters, 0, 0);
1814
1815         x86_pmu_format_group.attrs = x86_pmu.format_attrs;
1816
1817         if (x86_pmu.caps_attrs) {
1818                 struct attribute **tmp;
1819
1820                 tmp = merge_attr(x86_pmu_caps_group.attrs, x86_pmu.caps_attrs);
1821                 if (!WARN_ON(!tmp))
1822                         x86_pmu_caps_group.attrs = tmp;
1823         }
1824
1825         if (x86_pmu.event_attrs)
1826                 x86_pmu_events_group.attrs = x86_pmu.event_attrs;
1827
1828         if (!x86_pmu.events_sysfs_show)
1829                 x86_pmu_events_group.attrs = &empty_attrs;
1830         else
1831                 filter_events(x86_pmu_events_group.attrs);
1832
1833         if (x86_pmu.cpu_events) {
1834                 struct attribute **tmp;
1835
1836                 tmp = merge_attr(x86_pmu_events_group.attrs, x86_pmu.cpu_events);
1837                 if (!WARN_ON(!tmp))
1838                         x86_pmu_events_group.attrs = tmp;
1839         }
1840
1841         if (x86_pmu.attrs) {
1842                 struct attribute **tmp;
1843
1844                 tmp = merge_attr(x86_pmu_attr_group.attrs, x86_pmu.attrs);
1845                 if (!WARN_ON(!tmp))
1846                         x86_pmu_attr_group.attrs = tmp;
1847         }
1848
1849         pr_info("... version:                %d\n",     x86_pmu.version);
1850         pr_info("... bit width:              %d\n",     x86_pmu.cntval_bits);
1851         pr_info("... generic registers:      %d\n",     x86_pmu.num_counters);
1852         pr_info("... value mask:             %016Lx\n", x86_pmu.cntval_mask);
1853         pr_info("... max period:             %016Lx\n", x86_pmu.max_period);
1854         pr_info("... fixed-purpose events:   %d\n",     x86_pmu.num_counters_fixed);
1855         pr_info("... event mask:             %016Lx\n", x86_pmu.intel_ctrl);
1856
1857         /*
1858          * Install callbacks. Core will call them for each online
1859          * cpu.
1860          */
1861         err = cpuhp_setup_state(CPUHP_PERF_X86_PREPARE, "perf/x86:prepare",
1862                                 x86_pmu_prepare_cpu, x86_pmu_dead_cpu);
1863         if (err)
1864                 return err;
1865
1866         err = cpuhp_setup_state(CPUHP_AP_PERF_X86_STARTING,
1867                                 "perf/x86:starting", x86_pmu_starting_cpu,
1868                                 x86_pmu_dying_cpu);
1869         if (err)
1870                 goto out;
1871
1872         err = cpuhp_setup_state(CPUHP_AP_PERF_X86_ONLINE, "perf/x86:online",
1873                                 x86_pmu_online_cpu, NULL);
1874         if (err)
1875                 goto out1;
1876
1877         err = perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
1878         if (err)
1879                 goto out2;
1880
1881         return 0;
1882
1883 out2:
1884         cpuhp_remove_state(CPUHP_AP_PERF_X86_ONLINE);
1885 out1:
1886         cpuhp_remove_state(CPUHP_AP_PERF_X86_STARTING);
1887 out:
1888         cpuhp_remove_state(CPUHP_PERF_X86_PREPARE);
1889         return err;
1890 }
1891 early_initcall(init_hw_perf_events);
1892
1893 static inline void x86_pmu_read(struct perf_event *event)
1894 {
1895         if (x86_pmu.read)
1896                 return x86_pmu.read(event);
1897         x86_perf_event_update(event);
1898 }
1899
1900 /*
1901  * Start group events scheduling transaction
1902  * Set the flag to make pmu::enable() not perform the
1903  * schedulability test, it will be performed at commit time
1904  *
1905  * We only support PERF_PMU_TXN_ADD transactions. Save the
1906  * transaction flags but otherwise ignore non-PERF_PMU_TXN_ADD
1907  * transactions.
1908  */
1909 static void x86_pmu_start_txn(struct pmu *pmu, unsigned int txn_flags)
1910 {
1911         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1912
1913         WARN_ON_ONCE(cpuc->txn_flags);          /* txn already in flight */
1914
1915         cpuc->txn_flags = txn_flags;
1916         if (txn_flags & ~PERF_PMU_TXN_ADD)
1917                 return;
1918
1919         perf_pmu_disable(pmu);
1920         __this_cpu_write(cpu_hw_events.n_txn, 0);
1921 }
1922
1923 /*
1924  * Stop group events scheduling transaction
1925  * Clear the flag and pmu::enable() will perform the
1926  * schedulability test.
1927  */
1928 static void x86_pmu_cancel_txn(struct pmu *pmu)
1929 {
1930         unsigned int txn_flags;
1931         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1932
1933         WARN_ON_ONCE(!cpuc->txn_flags); /* no txn in flight */
1934
1935         txn_flags = cpuc->txn_flags;
1936         cpuc->txn_flags = 0;
1937         if (txn_flags & ~PERF_PMU_TXN_ADD)
1938                 return;
1939
1940         /*
1941          * Truncate collected array by the number of events added in this
1942          * transaction. See x86_pmu_add() and x86_pmu_*_txn().
1943          */
1944         __this_cpu_sub(cpu_hw_events.n_added, __this_cpu_read(cpu_hw_events.n_txn));
1945         __this_cpu_sub(cpu_hw_events.n_events, __this_cpu_read(cpu_hw_events.n_txn));
1946         perf_pmu_enable(pmu);
1947 }
1948
1949 /*
1950  * Commit group events scheduling transaction
1951  * Perform the group schedulability test as a whole
1952  * Return 0 if success
1953  *
1954  * Does not cancel the transaction on failure; expects the caller to do this.
1955  */
1956 static int x86_pmu_commit_txn(struct pmu *pmu)
1957 {
1958         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1959         int assign[X86_PMC_IDX_MAX];
1960         int n, ret;
1961
1962         WARN_ON_ONCE(!cpuc->txn_flags); /* no txn in flight */
1963
1964         if (cpuc->txn_flags & ~PERF_PMU_TXN_ADD) {
1965                 cpuc->txn_flags = 0;
1966                 return 0;
1967         }
1968
1969         n = cpuc->n_events;
1970
1971         if (!x86_pmu_initialized())
1972                 return -EAGAIN;
1973
1974         ret = x86_pmu.schedule_events(cpuc, n, assign);
1975         if (ret)
1976                 return ret;
1977
1978         /*
1979          * copy new assignment, now we know it is possible
1980          * will be used by hw_perf_enable()
1981          */
1982         memcpy(cpuc->assign, assign, n*sizeof(int));
1983
1984         cpuc->txn_flags = 0;
1985         perf_pmu_enable(pmu);
1986         return 0;
1987 }
1988 /*
1989  * a fake_cpuc is used to validate event groups. Due to
1990  * the extra reg logic, we need to also allocate a fake
1991  * per_core and per_cpu structure. Otherwise, group events
1992  * using extra reg may conflict without the kernel being
1993  * able to catch this when the last event gets added to
1994  * the group.
1995  */
1996 static void free_fake_cpuc(struct cpu_hw_events *cpuc)
1997 {
1998         kfree(cpuc->shared_regs);
1999         kfree(cpuc);
2000 }
2001
2002 static struct cpu_hw_events *allocate_fake_cpuc(void)
2003 {
2004         struct cpu_hw_events *cpuc;
2005         int cpu = raw_smp_processor_id();
2006
2007         cpuc = kzalloc(sizeof(*cpuc), GFP_KERNEL);
2008         if (!cpuc)
2009                 return ERR_PTR(-ENOMEM);
2010
2011         /* only needed, if we have extra_regs */
2012         if (x86_pmu.extra_regs) {
2013                 cpuc->shared_regs = allocate_shared_regs(cpu);
2014                 if (!cpuc->shared_regs)
2015                         goto error;
2016         }
2017         cpuc->is_fake = 1;
2018         return cpuc;
2019 error:
2020         free_fake_cpuc(cpuc);
2021         return ERR_PTR(-ENOMEM);
2022 }
2023
2024 /*
2025  * validate that we can schedule this event
2026  */
2027 static int validate_event(struct perf_event *event)
2028 {
2029         struct cpu_hw_events *fake_cpuc;
2030         struct event_constraint *c;
2031         int ret = 0;
2032
2033         fake_cpuc = allocate_fake_cpuc();
2034         if (IS_ERR(fake_cpuc))
2035                 return PTR_ERR(fake_cpuc);
2036
2037         c = x86_pmu.get_event_constraints(fake_cpuc, -1, event);
2038
2039         if (!c || !c->weight)
2040                 ret = -EINVAL;
2041
2042         if (x86_pmu.put_event_constraints)
2043                 x86_pmu.put_event_constraints(fake_cpuc, event);
2044
2045         free_fake_cpuc(fake_cpuc);
2046
2047         return ret;
2048 }
2049
2050 /*
2051  * validate a single event group
2052  *
2053  * validation include:
2054  *      - check events are compatible which each other
2055  *      - events do not compete for the same counter
2056  *      - number of events <= number of counters
2057  *
2058  * validation ensures the group can be loaded onto the
2059  * PMU if it was the only group available.
2060  */
2061 static int validate_group(struct perf_event *event)
2062 {
2063         struct perf_event *leader = event->group_leader;
2064         struct cpu_hw_events *fake_cpuc;
2065         int ret = -EINVAL, n;
2066
2067         fake_cpuc = allocate_fake_cpuc();
2068         if (IS_ERR(fake_cpuc))
2069                 return PTR_ERR(fake_cpuc);
2070         /*
2071          * the event is not yet connected with its
2072          * siblings therefore we must first collect
2073          * existing siblings, then add the new event
2074          * before we can simulate the scheduling
2075          */
2076         n = collect_events(fake_cpuc, leader, true);
2077         if (n < 0)
2078                 goto out;
2079
2080         fake_cpuc->n_events = n;
2081         n = collect_events(fake_cpuc, event, false);
2082         if (n < 0)
2083                 goto out;
2084
2085         fake_cpuc->n_events = n;
2086
2087         ret = x86_pmu.schedule_events(fake_cpuc, n, NULL);
2088
2089 out:
2090         free_fake_cpuc(fake_cpuc);
2091         return ret;
2092 }
2093
2094 static int x86_pmu_event_init(struct perf_event *event)
2095 {
2096         struct pmu *tmp;
2097         int err;
2098
2099         switch (event->attr.type) {
2100         case PERF_TYPE_RAW:
2101         case PERF_TYPE_HARDWARE:
2102         case PERF_TYPE_HW_CACHE:
2103                 break;
2104
2105         default:
2106                 return -ENOENT;
2107         }
2108
2109         err = __x86_pmu_event_init(event);
2110         if (!err) {
2111                 /*
2112                  * we temporarily connect event to its pmu
2113                  * such that validate_group() can classify
2114                  * it as an x86 event using is_x86_event()
2115                  */
2116                 tmp = event->pmu;
2117                 event->pmu = &pmu;
2118
2119                 if (event->group_leader != event)
2120                         err = validate_group(event);
2121                 else
2122                         err = validate_event(event);
2123
2124                 event->pmu = tmp;
2125         }
2126         if (err) {
2127                 if (event->destroy)
2128                         event->destroy(event);
2129         }
2130
2131         if (READ_ONCE(x86_pmu.attr_rdpmc) &&
2132             !(event->hw.flags & PERF_X86_EVENT_LARGE_PEBS))
2133                 event->hw.flags |= PERF_X86_EVENT_RDPMC_ALLOWED;
2134
2135         return err;
2136 }
2137
2138 static void refresh_pce(void *ignored)
2139 {
2140         load_mm_cr4(this_cpu_read(cpu_tlbstate.loaded_mm));
2141 }
2142
2143 static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm)
2144 {
2145         if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
2146                 return;
2147
2148         /*
2149          * This function relies on not being called concurrently in two
2150          * tasks in the same mm.  Otherwise one task could observe
2151          * perf_rdpmc_allowed > 1 and return all the way back to
2152          * userspace with CR4.PCE clear while another task is still
2153          * doing on_each_cpu_mask() to propagate CR4.PCE.
2154          *
2155          * For now, this can't happen because all callers hold mmap_sem
2156          * for write.  If this changes, we'll need a different solution.
2157          */
2158         lockdep_assert_held_exclusive(&mm->mmap_sem);
2159
2160         if (atomic_inc_return(&mm->context.perf_rdpmc_allowed) == 1)
2161                 on_each_cpu_mask(mm_cpumask(mm), refresh_pce, NULL, 1);
2162 }
2163
2164 static void x86_pmu_event_unmapped(struct perf_event *event, struct mm_struct *mm)
2165 {
2166
2167         if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
2168                 return;
2169
2170         if (atomic_dec_and_test(&mm->context.perf_rdpmc_allowed))
2171                 on_each_cpu_mask(mm_cpumask(mm), refresh_pce, NULL, 1);
2172 }
2173
2174 static int x86_pmu_event_idx(struct perf_event *event)
2175 {
2176         int idx = event->hw.idx;
2177
2178         if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
2179                 return 0;
2180
2181         if (x86_pmu.num_counters_fixed && idx >= INTEL_PMC_IDX_FIXED) {
2182                 idx -= INTEL_PMC_IDX_FIXED;
2183                 idx |= 1 << 30;
2184         }
2185
2186         return idx + 1;
2187 }
2188
2189 static ssize_t get_attr_rdpmc(struct device *cdev,
2190                               struct device_attribute *attr,
2191                               char *buf)
2192 {
2193         return snprintf(buf, 40, "%d\n", x86_pmu.attr_rdpmc);
2194 }
2195
2196 static ssize_t set_attr_rdpmc(struct device *cdev,
2197                               struct device_attribute *attr,
2198                               const char *buf, size_t count)
2199 {
2200         unsigned long val;
2201         ssize_t ret;
2202
2203         ret = kstrtoul(buf, 0, &val);
2204         if (ret)
2205                 return ret;
2206
2207         if (val > 2)
2208                 return -EINVAL;
2209
2210         if (x86_pmu.attr_rdpmc_broken)
2211                 return -ENOTSUPP;
2212
2213         if ((val == 2) != (x86_pmu.attr_rdpmc == 2)) {
2214                 /*
2215                  * Changing into or out of always available, aka
2216                  * perf-event-bypassing mode.  This path is extremely slow,
2217                  * but only root can trigger it, so it's okay.
2218                  */
2219                 if (val == 2)
2220                         static_branch_inc(&rdpmc_always_available_key);
2221                 else
2222                         static_branch_dec(&rdpmc_always_available_key);
2223                 on_each_cpu(refresh_pce, NULL, 1);
2224         }
2225
2226         x86_pmu.attr_rdpmc = val;
2227
2228         return count;
2229 }
2230
2231 static DEVICE_ATTR(rdpmc, S_IRUSR | S_IWUSR, get_attr_rdpmc, set_attr_rdpmc);
2232
2233 static struct attribute *x86_pmu_attrs[] = {
2234         &dev_attr_rdpmc.attr,
2235         NULL,
2236 };
2237
2238 static struct attribute_group x86_pmu_attr_group __ro_after_init = {
2239         .attrs = x86_pmu_attrs,
2240 };
2241
2242 static ssize_t max_precise_show(struct device *cdev,
2243                                   struct device_attribute *attr,
2244                                   char *buf)
2245 {
2246         return snprintf(buf, PAGE_SIZE, "%d\n", x86_pmu_max_precise());
2247 }
2248
2249 static DEVICE_ATTR_RO(max_precise);
2250
2251 static struct attribute *x86_pmu_caps_attrs[] = {
2252         &dev_attr_max_precise.attr,
2253         NULL
2254 };
2255
2256 static struct attribute_group x86_pmu_caps_group __ro_after_init = {
2257         .name = "caps",
2258         .attrs = x86_pmu_caps_attrs,
2259 };
2260
2261 static const struct attribute_group *x86_pmu_attr_groups[] = {
2262         &x86_pmu_attr_group,
2263         &x86_pmu_format_group,
2264         &x86_pmu_events_group,
2265         &x86_pmu_caps_group,
2266         NULL,
2267 };
2268
2269 static void x86_pmu_sched_task(struct perf_event_context *ctx, bool sched_in)
2270 {
2271         if (x86_pmu.sched_task)
2272                 x86_pmu.sched_task(ctx, sched_in);
2273 }
2274
2275 void perf_check_microcode(void)
2276 {
2277         if (x86_pmu.check_microcode)
2278                 x86_pmu.check_microcode();
2279 }
2280
2281 static struct pmu pmu = {
2282         .pmu_enable             = x86_pmu_enable,
2283         .pmu_disable            = x86_pmu_disable,
2284
2285         .attr_groups            = x86_pmu_attr_groups,
2286
2287         .event_init             = x86_pmu_event_init,
2288
2289         .event_mapped           = x86_pmu_event_mapped,
2290         .event_unmapped         = x86_pmu_event_unmapped,
2291
2292         .add                    = x86_pmu_add,
2293         .del                    = x86_pmu_del,
2294         .start                  = x86_pmu_start,
2295         .stop                   = x86_pmu_stop,
2296         .read                   = x86_pmu_read,
2297
2298         .start_txn              = x86_pmu_start_txn,
2299         .cancel_txn             = x86_pmu_cancel_txn,
2300         .commit_txn             = x86_pmu_commit_txn,
2301
2302         .event_idx              = x86_pmu_event_idx,
2303         .sched_task             = x86_pmu_sched_task,
2304         .task_ctx_size          = sizeof(struct x86_perf_task_context),
2305 };
2306
2307 void arch_perf_update_userpage(struct perf_event *event,
2308                                struct perf_event_mmap_page *userpg, u64 now)
2309 {
2310         struct cyc2ns_data data;
2311         u64 offset;
2312
2313         userpg->cap_user_time = 0;
2314         userpg->cap_user_time_zero = 0;
2315         userpg->cap_user_rdpmc =
2316                 !!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED);
2317         userpg->pmc_width = x86_pmu.cntval_bits;
2318
2319         if (!using_native_sched_clock() || !sched_clock_stable())
2320                 return;
2321
2322         cyc2ns_read_begin(&data);
2323
2324         offset = data.cyc2ns_offset + __sched_clock_offset;
2325
2326         /*
2327          * Internal timekeeping for enabled/running/stopped times
2328          * is always in the local_clock domain.
2329          */
2330         userpg->cap_user_time = 1;
2331         userpg->time_mult = data.cyc2ns_mul;
2332         userpg->time_shift = data.cyc2ns_shift;
2333         userpg->time_offset = offset - now;
2334
2335         /*
2336          * cap_user_time_zero doesn't make sense when we're using a different
2337          * time base for the records.
2338          */
2339         if (!event->attr.use_clockid) {
2340                 userpg->cap_user_time_zero = 1;
2341                 userpg->time_zero = offset;
2342         }
2343
2344         cyc2ns_read_end();
2345 }
2346
2347 void
2348 perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
2349 {
2350         struct unwind_state state;
2351         unsigned long addr;
2352
2353         if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
2354                 /* TODO: We don't support guest os callchain now */
2355                 return;
2356         }
2357
2358         if (perf_callchain_store(entry, regs->ip))
2359                 return;
2360
2361         for (unwind_start(&state, current, regs, NULL); !unwind_done(&state);
2362              unwind_next_frame(&state)) {
2363                 addr = unwind_get_return_address(&state);
2364                 if (!addr || perf_callchain_store(entry, addr))
2365                         return;
2366         }
2367 }
2368
2369 static inline int
2370 valid_user_frame(const void __user *fp, unsigned long size)
2371 {
2372         return (__range_not_ok(fp, size, TASK_SIZE) == 0);
2373 }
2374
2375 static unsigned long get_segment_base(unsigned int segment)
2376 {
2377         struct desc_struct *desc;
2378         unsigned int idx = segment >> 3;
2379
2380         if ((segment & SEGMENT_TI_MASK) == SEGMENT_LDT) {
2381 #ifdef CONFIG_MODIFY_LDT_SYSCALL
2382                 struct ldt_struct *ldt;
2383
2384                 /* IRQs are off, so this synchronizes with smp_store_release */
2385                 ldt = READ_ONCE(current->active_mm->context.ldt);
2386                 if (!ldt || idx >= ldt->nr_entries)
2387                         return 0;
2388
2389                 desc = &ldt->entries[idx];
2390 #else
2391                 return 0;
2392 #endif
2393         } else {
2394                 if (idx >= GDT_ENTRIES)
2395                         return 0;
2396
2397                 desc = raw_cpu_ptr(gdt_page.gdt) + idx;
2398         }
2399
2400         return get_desc_base(desc);
2401 }
2402
2403 #ifdef CONFIG_IA32_EMULATION
2404
2405 #include <linux/compat.h>
2406
2407 static inline int
2408 perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry)
2409 {
2410         /* 32-bit process in 64-bit kernel. */
2411         unsigned long ss_base, cs_base;
2412         struct stack_frame_ia32 frame;
2413         const void __user *fp;
2414
2415         if (!test_thread_flag(TIF_IA32))
2416                 return 0;
2417
2418         cs_base = get_segment_base(regs->cs);
2419         ss_base = get_segment_base(regs->ss);
2420
2421         fp = compat_ptr(ss_base + regs->bp);
2422         pagefault_disable();
2423         while (entry->nr < entry->max_stack) {
2424                 unsigned long bytes;
2425                 frame.next_frame     = 0;
2426                 frame.return_address = 0;
2427
2428                 if (!valid_user_frame(fp, sizeof(frame)))
2429                         break;
2430
2431                 bytes = __copy_from_user_nmi(&frame.next_frame, fp, 4);
2432                 if (bytes != 0)
2433                         break;
2434                 bytes = __copy_from_user_nmi(&frame.return_address, fp+4, 4);
2435                 if (bytes != 0)
2436                         break;
2437
2438                 perf_callchain_store(entry, cs_base + frame.return_address);
2439                 fp = compat_ptr(ss_base + frame.next_frame);
2440         }
2441         pagefault_enable();
2442         return 1;
2443 }
2444 #else
2445 static inline int
2446 perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry)
2447 {
2448     return 0;
2449 }
2450 #endif
2451
2452 void
2453 perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
2454 {
2455         struct stack_frame frame;
2456         const unsigned long __user *fp;
2457
2458         if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
2459                 /* TODO: We don't support guest os callchain now */
2460                 return;
2461         }
2462
2463         /*
2464          * We don't know what to do with VM86 stacks.. ignore them for now.
2465          */
2466         if (regs->flags & (X86_VM_MASK | PERF_EFLAGS_VM))
2467                 return;
2468
2469         fp = (unsigned long __user *)regs->bp;
2470
2471         perf_callchain_store(entry, regs->ip);
2472
2473         if (!nmi_uaccess_okay())
2474                 return;
2475
2476         if (perf_callchain_user32(regs, entry))
2477                 return;
2478
2479         pagefault_disable();
2480         while (entry->nr < entry->max_stack) {
2481                 unsigned long bytes;
2482
2483                 frame.next_frame             = NULL;
2484                 frame.return_address = 0;
2485
2486                 if (!valid_user_frame(fp, sizeof(frame)))
2487                         break;
2488
2489                 bytes = __copy_from_user_nmi(&frame.next_frame, fp, sizeof(*fp));
2490                 if (bytes != 0)
2491                         break;
2492                 bytes = __copy_from_user_nmi(&frame.return_address, fp + 1, sizeof(*fp));
2493                 if (bytes != 0)
2494                         break;
2495
2496                 perf_callchain_store(entry, frame.return_address);
2497                 fp = (void __user *)frame.next_frame;
2498         }
2499         pagefault_enable();
2500 }
2501
2502 /*
2503  * Deal with code segment offsets for the various execution modes:
2504  *
2505  *   VM86 - the good olde 16 bit days, where the linear address is
2506  *          20 bits and we use regs->ip + 0x10 * regs->cs.
2507  *
2508  *   IA32 - Where we need to look at GDT/LDT segment descriptor tables
2509  *          to figure out what the 32bit base address is.
2510  *
2511  *    X32 - has TIF_X32 set, but is running in x86_64
2512  *
2513  * X86_64 - CS,DS,SS,ES are all zero based.
2514  */
2515 static unsigned long code_segment_base(struct pt_regs *regs)
2516 {
2517         /*
2518          * For IA32 we look at the GDT/LDT segment base to convert the
2519          * effective IP to a linear address.
2520          */
2521
2522 #ifdef CONFIG_X86_32
2523         /*
2524          * If we are in VM86 mode, add the segment offset to convert to a
2525          * linear address.
2526          */
2527         if (regs->flags & X86_VM_MASK)
2528                 return 0x10 * regs->cs;
2529
2530         if (user_mode(regs) && regs->cs != __USER_CS)
2531                 return get_segment_base(regs->cs);
2532 #else
2533         if (user_mode(regs) && !user_64bit_mode(regs) &&
2534             regs->cs != __USER32_CS)
2535                 return get_segment_base(regs->cs);
2536 #endif
2537         return 0;
2538 }
2539
2540 unsigned long perf_instruction_pointer(struct pt_regs *regs)
2541 {
2542         if (perf_guest_cbs && perf_guest_cbs->is_in_guest())
2543                 return perf_guest_cbs->get_guest_ip();
2544
2545         return regs->ip + code_segment_base(regs);
2546 }
2547
2548 unsigned long perf_misc_flags(struct pt_regs *regs)
2549 {
2550         int misc = 0;
2551
2552         if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
2553                 if (perf_guest_cbs->is_user_mode())
2554                         misc |= PERF_RECORD_MISC_GUEST_USER;
2555                 else
2556                         misc |= PERF_RECORD_MISC_GUEST_KERNEL;
2557         } else {
2558                 if (user_mode(regs))
2559                         misc |= PERF_RECORD_MISC_USER;
2560                 else
2561                         misc |= PERF_RECORD_MISC_KERNEL;
2562         }
2563
2564         if (regs->flags & PERF_EFLAGS_EXACT)
2565                 misc |= PERF_RECORD_MISC_EXACT_IP;
2566
2567         return misc;
2568 }
2569
2570 void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
2571 {
2572         cap->version            = x86_pmu.version;
2573         cap->num_counters_gp    = x86_pmu.num_counters;
2574         cap->num_counters_fixed = x86_pmu.num_counters_fixed;
2575         cap->bit_width_gp       = x86_pmu.cntval_bits;
2576         cap->bit_width_fixed    = x86_pmu.cntval_bits;
2577         cap->events_mask        = (unsigned int)x86_pmu.events_maskl;
2578         cap->events_mask_len    = x86_pmu.events_mask_len;
2579 }
2580 EXPORT_SYMBOL_GPL(perf_get_x86_pmu_capability);