linux/arch/x86/events/amd/uncore.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2013 Advanced Micro Devices, Inc.
   4 *
   5 * Author: Jacob Shin <jacob.shin@amd.com>
   6 */
   7
   8#include <linux/perf_event.h>
   9#include <linux/percpu.h>
  10#include <linux/types.h>
  11#include <linux/slab.h>
  12#include <linux/init.h>
  13#include <linux/cpu.h>
  14#include <linux/cpumask.h>
  15
  16#include <asm/cpufeature.h>
  17#include <asm/perf_event.h>
  18#include <asm/msr.h>
  19#include <asm/smp.h>
  20
  21#define NUM_COUNTERS_NB         4
  22#define NUM_COUNTERS_L2         4
  23#define NUM_COUNTERS_L3         6
  24#define MAX_COUNTERS            6
  25
  26#define RDPMC_BASE_NB           6
  27#define RDPMC_BASE_LLC          10
  28
  29#define COUNTER_SHIFT           16
  30
  31#undef pr_fmt
  32#define pr_fmt(fmt)     "amd_uncore: " fmt
  33
  34static int num_counters_llc;
  35static int num_counters_nb;
  36static bool l3_mask;
  37
  38static HLIST_HEAD(uncore_unused_list);
  39
  40struct amd_uncore {
  41        int id;
  42        int refcnt;
  43        int cpu;
  44        int num_counters;
  45        int rdpmc_base;
  46        u32 msr_base;
  47        cpumask_t *active_mask;
  48        struct pmu *pmu;
  49        struct perf_event *events[MAX_COUNTERS];
  50        struct hlist_node node;
  51};
  52
  53static struct amd_uncore * __percpu *amd_uncore_nb;
  54static struct amd_uncore * __percpu *amd_uncore_llc;
  55
  56static struct pmu amd_nb_pmu;
  57static struct pmu amd_llc_pmu;
  58
  59static cpumask_t amd_nb_active_mask;
  60static cpumask_t amd_llc_active_mask;
  61
  62static bool is_nb_event(struct perf_event *event)
  63{
  64        return event->pmu->type == amd_nb_pmu.type;
  65}
  66
  67static bool is_llc_event(struct perf_event *event)
  68{
  69        return event->pmu->type == amd_llc_pmu.type;
  70}
  71
  72static struct amd_uncore *event_to_amd_uncore(struct perf_event *event)
  73{
  74        if (is_nb_event(event) && amd_uncore_nb)
  75                return *per_cpu_ptr(amd_uncore_nb, event->cpu);
  76        else if (is_llc_event(event) && amd_uncore_llc)
  77                return *per_cpu_ptr(amd_uncore_llc, event->cpu);
  78
  79        return NULL;
  80}
  81
  82static void amd_uncore_read(struct perf_event *event)
  83{
  84        struct hw_perf_event *hwc = &event->hw;
  85        u64 prev, new;
  86        s64 delta;
  87
  88        /*
  89         * since we do not enable counter overflow interrupts,
  90         * we do not have to worry about prev_count changing on us
  91         */
  92
  93        prev = local64_read(&hwc->prev_count);
  94        rdpmcl(hwc->event_base_rdpmc, new);
  95        local64_set(&hwc->prev_count, new);
  96        delta = (new << COUNTER_SHIFT) - (prev << COUNTER_SHIFT);
  97        delta >>= COUNTER_SHIFT;
  98        local64_add(delta, &event->count);
  99}
 100
 101static void amd_uncore_start(struct perf_event *event, int flags)
 102{
 103        struct hw_perf_event *hwc = &event->hw;
 104
 105        if (flags & PERF_EF_RELOAD)
 106                wrmsrl(hwc->event_base, (u64)local64_read(&hwc->prev_count));
 107
 108        hwc->state = 0;
 109        wrmsrl(hwc->config_base, (hwc->config | ARCH_PERFMON_EVENTSEL_ENABLE));
 110        perf_event_update_userpage(event);
 111}
 112
 113static void amd_uncore_stop(struct perf_event *event, int flags)
 114{
 115        struct hw_perf_event *hwc = &event->hw;
 116
 117        wrmsrl(hwc->config_base, hwc->config);
 118        hwc->state |= PERF_HES_STOPPED;
 119
 120        if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
 121                amd_uncore_read(event);
 122                hwc->state |= PERF_HES_UPTODATE;
 123        }
 124}
 125
 126static int amd_uncore_add(struct perf_event *event, int flags)
 127{
 128        int i;
 129        struct amd_uncore *uncore = event_to_amd_uncore(event);
 130        struct hw_perf_event *hwc = &event->hw;
 131
 132        /* are we already assigned? */
 133        if (hwc->idx != -1 && uncore->events[hwc->idx] == event)
 134                goto out;
 135
 136        for (i = 0; i < uncore->num_counters; i++) {
 137                if (uncore->events[i] == event) {
 138                        hwc->idx = i;
 139                        goto out;
 140                }
 141        }
 142
 143        /* if not, take the first available counter */
 144        hwc->idx = -1;
 145        for (i = 0; i < uncore->num_counters; i++) {
 146                if (cmpxchg(&uncore->events[i], NULL, event) == NULL) {
 147                        hwc->idx = i;
 148                        break;
 149                }
 150        }
 151
 152out:
 153        if (hwc->idx == -1)
 154                return -EBUSY;
 155
 156        hwc->config_base = uncore->msr_base + (2 * hwc->idx);
 157        hwc->event_base = uncore->msr_base + 1 + (2 * hwc->idx);
 158        hwc->event_base_rdpmc = uncore->rdpmc_base + hwc->idx;
 159        hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
 160
 161        if (flags & PERF_EF_START)
 162                amd_uncore_start(event, PERF_EF_RELOAD);
 163
 164        return 0;
 165}
 166
 167static void amd_uncore_del(struct perf_event *event, int flags)
 168{
 169        int i;
 170        struct amd_uncore *uncore = event_to_amd_uncore(event);
 171        struct hw_perf_event *hwc = &event->hw;
 172
 173        amd_uncore_stop(event, PERF_EF_UPDATE);
 174
 175        for (i = 0; i < uncore->num_counters; i++) {
 176                if (cmpxchg(&uncore->events[i], event, NULL) == event)
 177                        break;
 178        }
 179
 180        hwc->idx = -1;
 181}
 182
 183static int amd_uncore_event_init(struct perf_event *event)
 184{
 185        struct amd_uncore *uncore;
 186        struct hw_perf_event *hwc = &event->hw;
 187
 188        if (event->attr.type != event->pmu->type)
 189                return -ENOENT;
 190
 191        /*
 192         * NB and Last level cache counters (MSRs) are shared across all cores
 193         * that share the same NB / Last level cache. Interrupts can be directed
 194         * to a single target core, however, event counts generated by processes
 195         * running on other cores cannot be masked out. So we do not support
 196         * sampling and per-thread events.
 197         */
 198        if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
 199                return -EINVAL;
 200
 201        /* and we do not enable counter overflow interrupts */
 202        hwc->config = event->attr.config & AMD64_RAW_EVENT_MASK_NB;
 203        hwc->idx = -1;
 204
 205        if (event->cpu < 0)
 206                return -EINVAL;
 207
 208        /*
 209         * SliceMask and ThreadMask need to be set for certain L3 events in
 210         * Family 17h. For other events, the two fields do not affect the count.
 211         */
 212        if (l3_mask && is_llc_event(event)) {
 213                int thread = 2 * (cpu_data(event->cpu).cpu_core_id % 4);
 214
 215                if (smp_num_siblings > 1)
 216                        thread += cpu_data(event->cpu).apicid & 1;
 217
 218                hwc->config |= (1ULL << (AMD64_L3_THREAD_SHIFT + thread) &
 219                                AMD64_L3_THREAD_MASK) | AMD64_L3_SLICE_MASK;
 220        }
 221
 222        uncore = event_to_amd_uncore(event);
 223        if (!uncore)
 224                return -ENODEV;
 225
 226        /*
 227         * since request can come in to any of the shared cores, we will remap
 228         * to a single common cpu.
 229         */
 230        event->cpu = uncore->cpu;
 231
 232        return 0;
 233}
 234
 235static ssize_t amd_uncore_attr_show_cpumask(struct device *dev,
 236                                            struct device_attribute *attr,
 237                                            char *buf)
 238{
 239        cpumask_t *active_mask;
 240        struct pmu *pmu = dev_get_drvdata(dev);
 241
 242        if (pmu->type == amd_nb_pmu.type)
 243                active_mask = &amd_nb_active_mask;
 244        else if (pmu->type == amd_llc_pmu.type)
 245                active_mask = &amd_llc_active_mask;
 246        else
 247                return 0;
 248
 249        return cpumap_print_to_pagebuf(true, buf, active_mask);
 250}
 251static DEVICE_ATTR(cpumask, S_IRUGO, amd_uncore_attr_show_cpumask, NULL);
 252
 253static struct attribute *amd_uncore_attrs[] = {
 254        &dev_attr_cpumask.attr,
 255        NULL,
 256};
 257
 258static struct attribute_group amd_uncore_attr_group = {
 259        .attrs = amd_uncore_attrs,
 260};
 261
 262/*
 263 * Similar to PMU_FORMAT_ATTR but allowing for format_attr to be assigned based
 264 * on family
 265 */
 266#define AMD_FORMAT_ATTR(_dev, _name, _format)                                \
 267static ssize_t                                                               \
 268_dev##_show##_name(struct device *dev,                                       \
 269                struct device_attribute *attr,                               \
 270                char *page)                                                  \
 271{                                                                            \
 272        BUILD_BUG_ON(sizeof(_format) >= PAGE_SIZE);                          \
 273        return sprintf(page, _format "\n");                                  \
 274}                                                                            \
 275static struct device_attribute format_attr_##_dev##_name = __ATTR_RO(_dev);
 276
 277/* Used for each uncore counter type */
 278#define AMD_ATTRIBUTE(_name)                                                 \
 279static struct attribute *amd_uncore_format_attr_##_name[] = {                \
 280        &format_attr_event_##_name.attr,                                     \
 281        &format_attr_umask.attr,                                             \
 282        NULL,                                                                \
 283};                                                                           \
 284static struct attribute_group amd_uncore_format_group_##_name = {            \
 285        .name = "format",                                                    \
 286        .attrs = amd_uncore_format_attr_##_name,                             \
 287};                                                                           \
 288static const struct attribute_group *amd_uncore_attr_groups_##_name[] = {    \
 289        &amd_uncore_attr_group,                                              \
 290        &amd_uncore_format_group_##_name,                                    \
 291        NULL,                                                                \
 292};
 293
 294AMD_FORMAT_ATTR(event, , "config:0-7,32-35");
 295AMD_FORMAT_ATTR(umask, , "config:8-15");
 296AMD_FORMAT_ATTR(event, _df, "config:0-7,32-35,59-60");
 297AMD_FORMAT_ATTR(event, _l3, "config:0-7");
 298AMD_ATTRIBUTE(df);
 299AMD_ATTRIBUTE(l3);
 300
 301static struct pmu amd_nb_pmu = {
 302        .task_ctx_nr    = perf_invalid_context,
 303        .event_init     = amd_uncore_event_init,
 304        .add            = amd_uncore_add,
 305        .del            = amd_uncore_del,
 306        .start          = amd_uncore_start,
 307        .stop           = amd_uncore_stop,
 308        .read           = amd_uncore_read,
 309        .capabilities   = PERF_PMU_CAP_NO_EXCLUDE,
 310};
 311
 312static struct pmu amd_llc_pmu = {
 313        .task_ctx_nr    = perf_invalid_context,
 314        .event_init     = amd_uncore_event_init,
 315        .add            = amd_uncore_add,
 316        .del            = amd_uncore_del,
 317        .start          = amd_uncore_start,
 318        .stop           = amd_uncore_stop,
 319        .read           = amd_uncore_read,
 320        .capabilities   = PERF_PMU_CAP_NO_EXCLUDE,
 321};
 322
 323static struct amd_uncore *amd_uncore_alloc(unsigned int cpu)
 324{
 325        return kzalloc_node(sizeof(struct amd_uncore), GFP_KERNEL,
 326                        cpu_to_node(cpu));
 327}
 328
 329static int amd_uncore_cpu_up_prepare(unsigned int cpu)
 330{
 331        struct amd_uncore *uncore_nb = NULL, *uncore_llc;
 332
 333        if (amd_uncore_nb) {
 334                uncore_nb = amd_uncore_alloc(cpu);
 335                if (!uncore_nb)
 336                        goto fail;
 337                uncore_nb->cpu = cpu;
 338                uncore_nb->num_counters = num_counters_nb;
 339                uncore_nb->rdpmc_base = RDPMC_BASE_NB;
 340                uncore_nb->msr_base = MSR_F15H_NB_PERF_CTL;
 341                uncore_nb->active_mask = &amd_nb_active_mask;
 342                uncore_nb->pmu = &amd_nb_pmu;
 343                uncore_nb->id = -1;
 344                *per_cpu_ptr(amd_uncore_nb, cpu) = uncore_nb;
 345        }
 346
 347        if (amd_uncore_llc) {
 348                uncore_llc = amd_uncore_alloc(cpu);
 349                if (!uncore_llc)
 350                        goto fail;
 351                uncore_llc->cpu = cpu;
 352                uncore_llc->num_counters = num_counters_llc;
 353                uncore_llc->rdpmc_base = RDPMC_BASE_LLC;
 354                uncore_llc->msr_base = MSR_F16H_L2I_PERF_CTL;
 355                uncore_llc->active_mask = &amd_llc_active_mask;
 356                uncore_llc->pmu = &amd_llc_pmu;
 357                uncore_llc->id = -1;
 358                *per_cpu_ptr(amd_uncore_llc, cpu) = uncore_llc;
 359        }
 360
 361        return 0;
 362
 363fail:
 364        if (amd_uncore_nb)
 365                *per_cpu_ptr(amd_uncore_nb, cpu) = NULL;
 366        kfree(uncore_nb);
 367        return -ENOMEM;
 368}
 369
 370static struct amd_uncore *
 371amd_uncore_find_online_sibling(struct amd_uncore *this,
 372                               struct amd_uncore * __percpu *uncores)
 373{
 374        unsigned int cpu;
 375        struct amd_uncore *that;
 376
 377        for_each_online_cpu(cpu) {
 378                that = *per_cpu_ptr(uncores, cpu);
 379
 380                if (!that)
 381                        continue;
 382
 383                if (this == that)
 384                        continue;
 385
 386                if (this->id == that->id) {
 387                        hlist_add_head(&this->node, &uncore_unused_list);
 388                        this = that;
 389                        break;
 390                }
 391        }
 392
 393        this->refcnt++;
 394        return this;
 395}
 396
 397static int amd_uncore_cpu_starting(unsigned int cpu)
 398{
 399        unsigned int eax, ebx, ecx, edx;
 400        struct amd_uncore *uncore;
 401
 402        if (amd_uncore_nb) {
 403                uncore = *per_cpu_ptr(amd_uncore_nb, cpu);
 404                cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
 405                uncore->id = ecx & 0xff;
 406
 407                uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_nb);
 408                *per_cpu_ptr(amd_uncore_nb, cpu) = uncore;
 409        }
 410
 411        if (amd_uncore_llc) {
 412                uncore = *per_cpu_ptr(amd_uncore_llc, cpu);
 413                uncore->id = per_cpu(cpu_llc_id, cpu);
 414
 415                uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_llc);
 416                *per_cpu_ptr(amd_uncore_llc, cpu) = uncore;
 417        }
 418
 419        return 0;
 420}
 421
 422static void uncore_clean_online(void)
 423{
 424        struct amd_uncore *uncore;
 425        struct hlist_node *n;
 426
 427        hlist_for_each_entry_safe(uncore, n, &uncore_unused_list, node) {
 428                hlist_del(&uncore->node);
 429                kfree(uncore);
 430        }
 431}
 432
 433static void uncore_online(unsigned int cpu,
 434                          struct amd_uncore * __percpu *uncores)
 435{
 436        struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu);
 437
 438        uncore_clean_online();
 439
 440        if (cpu == uncore->cpu)
 441                cpumask_set_cpu(cpu, uncore->active_mask);
 442}
 443
 444static int amd_uncore_cpu_online(unsigned int cpu)
 445{
 446        if (amd_uncore_nb)
 447                uncore_online(cpu, amd_uncore_nb);
 448
 449        if (amd_uncore_llc)
 450                uncore_online(cpu, amd_uncore_llc);
 451
 452        return 0;
 453}
 454
 455static void uncore_down_prepare(unsigned int cpu,
 456                                struct amd_uncore * __percpu *uncores)
 457{
 458        unsigned int i;
 459        struct amd_uncore *this = *per_cpu_ptr(uncores, cpu);
 460
 461        if (this->cpu != cpu)
 462                return;
 463
 464        /* this cpu is going down, migrate to a shared sibling if possible */
 465        for_each_online_cpu(i) {
 466                struct amd_uncore *that = *per_cpu_ptr(uncores, i);
 467
 468                if (cpu == i)
 469                        continue;
 470
 471                if (this == that) {
 472                        perf_pmu_migrate_context(this->pmu, cpu, i);
 473                        cpumask_clear_cpu(cpu, that->active_mask);
 474                        cpumask_set_cpu(i, that->active_mask);
 475                        that->cpu = i;
 476                        break;
 477                }
 478        }
 479}
 480
 481static int amd_uncore_cpu_down_prepare(unsigned int cpu)
 482{
 483        if (amd_uncore_nb)
 484                uncore_down_prepare(cpu, amd_uncore_nb);
 485
 486        if (amd_uncore_llc)
 487                uncore_down_prepare(cpu, amd_uncore_llc);
 488
 489        return 0;
 490}
 491
 492static void uncore_dead(unsigned int cpu, struct amd_uncore * __percpu *uncores)
 493{
 494        struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu);
 495
 496        if (cpu == uncore->cpu)
 497                cpumask_clear_cpu(cpu, uncore->active_mask);
 498
 499        if (!--uncore->refcnt)
 500                kfree(uncore);
 501        *per_cpu_ptr(uncores, cpu) = NULL;
 502}
 503
 504static int amd_uncore_cpu_dead(unsigned int cpu)
 505{
 506        if (amd_uncore_nb)
 507                uncore_dead(cpu, amd_uncore_nb);
 508
 509        if (amd_uncore_llc)
 510                uncore_dead(cpu, amd_uncore_llc);
 511
 512        return 0;
 513}
 514
 515static int __init amd_uncore_init(void)
 516{
 517        int ret = -ENODEV;
 518
 519        if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
 520            boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
 521                return -ENODEV;
 522
 523        if (!boot_cpu_has(X86_FEATURE_TOPOEXT))
 524                return -ENODEV;
 525
 526        if (boot_cpu_data.x86 == 0x17 || boot_cpu_data.x86 == 0x18) {
 527                /*
 528                 * For F17h or F18h, the Northbridge counters are
 529                 * repurposed as Data Fabric counters. Also, L3
 530                 * counters are supported too. The PMUs are exported
 531                 * based on family as either L2 or L3 and NB or DF.
 532                 */
 533                num_counters_nb           = NUM_COUNTERS_NB;
 534                num_counters_llc          = NUM_COUNTERS_L3;
 535                amd_nb_pmu.name           = "amd_df";
 536                amd_llc_pmu.name          = "amd_l3";
 537                format_attr_event_df.show = &event_show_df;
 538                format_attr_event_l3.show = &event_show_l3;
 539                l3_mask                   = true;
 540        } else {
 541                num_counters_nb           = NUM_COUNTERS_NB;
 542                num_counters_llc          = NUM_COUNTERS_L2;
 543                amd_nb_pmu.name           = "amd_nb";
 544                amd_llc_pmu.name          = "amd_l2";
 545                format_attr_event_df      = format_attr_event;
 546                format_attr_event_l3      = format_attr_event;
 547                l3_mask                   = false;
 548        }
 549
 550        amd_nb_pmu.attr_groups  = amd_uncore_attr_groups_df;
 551        amd_llc_pmu.attr_groups = amd_uncore_attr_groups_l3;
 552
 553        if (boot_cpu_has(X86_FEATURE_PERFCTR_NB)) {
 554                amd_uncore_nb = alloc_percpu(struct amd_uncore *);
 555                if (!amd_uncore_nb) {
 556                        ret = -ENOMEM;
 557                        goto fail_nb;
 558                }
 559                ret = perf_pmu_register(&amd_nb_pmu, amd_nb_pmu.name, -1);
 560                if (ret)
 561                        goto fail_nb;
 562
 563                pr_info("%s NB counters detected\n",
 564                        boot_cpu_data.x86_vendor == X86_VENDOR_HYGON ?
 565                                "HYGON" : "AMD");
 566                ret = 0;
 567        }
 568
 569        if (boot_cpu_has(X86_FEATURE_PERFCTR_LLC)) {
 570                amd_uncore_llc = alloc_percpu(struct amd_uncore *);
 571                if (!amd_uncore_llc) {
 572                        ret = -ENOMEM;
 573                        goto fail_llc;
 574                }
 575                ret = perf_pmu_register(&amd_llc_pmu, amd_llc_pmu.name, -1);
 576                if (ret)
 577                        goto fail_llc;
 578
 579                pr_info("%s LLC counters detected\n",
 580                        boot_cpu_data.x86_vendor == X86_VENDOR_HYGON ?
 581                                "HYGON" : "AMD");
 582                ret = 0;
 583        }
 584
 585        /*
 586         * Install callbacks. Core will call them for each online cpu.
 587         */
 588        if (cpuhp_setup_state(CPUHP_PERF_X86_AMD_UNCORE_PREP,
 589                              "perf/x86/amd/uncore:prepare",
 590                              amd_uncore_cpu_up_prepare, amd_uncore_cpu_dead))
 591                goto fail_llc;
 592
 593        if (cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
 594                              "perf/x86/amd/uncore:starting",
 595                              amd_uncore_cpu_starting, NULL))
 596                goto fail_prep;
 597        if (cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
 598                              "perf/x86/amd/uncore:online",
 599                              amd_uncore_cpu_online,
 600                              amd_uncore_cpu_down_prepare))
 601                goto fail_start;
 602        return 0;
 603
 604fail_start:
 605        cpuhp_remove_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING);
 606fail_prep:
 607        cpuhp_remove_state(CPUHP_PERF_X86_AMD_UNCORE_PREP);
 608fail_llc:
 609        if (boot_cpu_has(X86_FEATURE_PERFCTR_NB))
 610                perf_pmu_unregister(&amd_nb_pmu);
 611        if (amd_uncore_llc)
 612                free_percpu(amd_uncore_llc);
 613fail_nb:
 614        if (amd_uncore_nb)
 615                free_percpu(amd_uncore_nb);
 616
 617        return ret;
 618}
 619device_initcall(amd_uncore_init);
 620