arch/x86/events/amd/uncore.c

   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
  34 static int num_counters_llc;
  35 static int num_counters_nb;
  36 static bool l3_mask;
  37
  38 static HLIST_HEAD(uncore_unused_list);
  39
  40 struct 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
  53 static struct amd_uncore * __percpu *amd_uncore_nb;
  54 static struct amd_uncore * __percpu *amd_uncore_llc;
  55
  56 static struct pmu amd_nb_pmu;
  57 static struct pmu amd_llc_pmu;
  58
  59 static cpumask_t amd_nb_active_mask;
  60 static cpumask_t amd_llc_active_mask;
  61
  62 static bool is_nb_event(struct perf_event *event)
  63 {
  64         return event->pmu->type == amd_nb_pmu.type;
  65 }
  66
  67 static bool is_llc_event(struct perf_event *event)
  68 {
  69         return event->pmu->type == amd_llc_pmu.type;
  70 }
  71
  72 static 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
  82 static 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
 101 static 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
 113 static 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
 126 static 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
 152 out:
 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
 167 static 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
 183 static 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
 235 static 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 }
 251 static DEVICE_ATTR(cpumask, S_IRUGO, amd_uncore_attr_show_cpumask, NULL);
 252
 253 static struct attribute *amd_uncore_attrs[] = {
 254         &dev_attr_cpumask.attr,
 255         NULL,
 256 };
 257
 258 static 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)                                \
 267 static 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 }                                                                            \
 275 static struct device_attribute format_attr_##_dev##_name = __ATTR_RO(_dev);
 276
 277 /* Used for each uncore counter type */
 278 #define AMD_ATTRIBUTE(_name)                                                 \
 279 static struct attribute *amd_uncore_format_attr_##_name[] = {                \
 280         &format_attr_event_##_name.attr,                                     \
 281         &format_attr_umask.attr,                                             \
 282         NULL,                                                                \
 283 };                                                                           \
 284 static struct attribute_group amd_uncore_format_group_##_name = {            \
 285         .name = "format",                                                    \
 286         .attrs = amd_uncore_format_attr_##_name,                             \
 287 };                                                                           \
 288 static const struct attribute_group *amd_uncore_attr_groups_##_name[] = {    \
 289         &amd_uncore_attr_group,                                              \
 290         &amd_uncore_format_group_##_name,                                    \
 291         NULL,                                                                \
 292 };
 293
 294 AMD_FORMAT_ATTR(event, , "config:0-7,32-35");
 295 AMD_FORMAT_ATTR(umask, , "config:8-15");
 296 AMD_FORMAT_ATTR(event, _df, "config:0-7,32-35,59-60");
 297 AMD_FORMAT_ATTR(event, _l3, "config:0-7");
 298 AMD_ATTRIBUTE(df);
 299 AMD_ATTRIBUTE(l3);
 300
 301 static 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
 312 static 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
 323 static 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
 329 static 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
 363 fail:
 364         if (amd_uncore_nb)
 365                 *per_cpu_ptr(amd_uncore_nb, cpu) = NULL;
 366         kfree(uncore_nb);
 367         return -ENOMEM;
 368 }
 369
 370 static struct amd_uncore *
 371 amd_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
 397 static 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
 422 static 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
 433 static 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
 444 static 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
 455 static 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
 481 static 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
 492 static 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
 504 static 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
 515 static 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
 604 fail_start:
 605         cpuhp_remove_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING);
 606 fail_prep:
 607         cpuhp_remove_state(CPUHP_PERF_X86_AMD_UNCORE_PREP);
 608 fail_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);
 613 fail_nb:
 614         if (amd_uncore_nb)
 615                 free_percpu(amd_uncore_nb);
 616
 617         return ret;
 618 }
 619 device_initcall(amd_uncore_init);