arch/x86/events/amd/uncore.c

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