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
  23 #define NUM_COUNTERS_NB         4
  24 #define NUM_COUNTERS_L2         4
  25 #define NUM_COUNTERS_L3         6
  26 #define MAX_COUNTERS            6
  27
  28 #define RDPMC_BASE_NB           6
  29 #define RDPMC_BASE_LLC          10
  30
  31 #define COUNTER_SHIFT           16
  32
  33 static int num_counters_llc;
  34 static int num_counters_nb;
  35
  36 static HLIST_HEAD(uncore_unused_list);
  37
  38 struct amd_uncore {
  39         int id;
  40         int refcnt;
  41         int cpu;
  42         int num_counters;
  43         int rdpmc_base;
  44         u32 msr_base;
  45         cpumask_t *active_mask;
  46         struct pmu *pmu;
  47         struct perf_event *events[MAX_COUNTERS];
  48         struct hlist_node node;
  49 };
  50
  51 static struct amd_uncore * __percpu *amd_uncore_nb;
  52 static struct amd_uncore * __percpu *amd_uncore_llc;
  53
  54 static struct pmu amd_nb_pmu;
  55 static struct pmu amd_llc_pmu;
  56
  57 static cpumask_t amd_nb_active_mask;
  58 static cpumask_t amd_llc_active_mask;
  59
  60 static bool is_nb_event(struct perf_event *event)
  61 {
  62         return event->pmu->type == amd_nb_pmu.type;
  63 }
  64
  65 static bool is_llc_event(struct perf_event *event)
  66 {
  67         return event->pmu->type == amd_llc_pmu.type;
  68 }
  69
  70 static struct amd_uncore *event_to_amd_uncore(struct perf_event *event)
  71 {
  72         if (is_nb_event(event) && amd_uncore_nb)
  73                 return *per_cpu_ptr(amd_uncore_nb, event->cpu);
  74         else if (is_llc_event(event) && amd_uncore_llc)
  75                 return *per_cpu_ptr(amd_uncore_llc, event->cpu);
  76
  77         return NULL;
  78 }
  79
  80 static void amd_uncore_read(struct perf_event *event)
  81 {
  82         struct hw_perf_event *hwc = &event->hw;
  83         u64 prev, new;
  84         s64 delta;
  85
  86         /*
  87          * since we do not enable counter overflow interrupts,
  88          * we do not have to worry about prev_count changing on us
  89          */
  90
  91         prev = local64_read(&hwc->prev_count);
  92         rdpmcl(hwc->event_base_rdpmc, new);
  93         local64_set(&hwc->prev_count, new);
  94         delta = (new << COUNTER_SHIFT) - (prev << COUNTER_SHIFT);
  95         delta >>= COUNTER_SHIFT;
  96         local64_add(delta, &event->count);
  97 }
  98
  99 static void amd_uncore_start(struct perf_event *event, int flags)
 100 {
 101         struct hw_perf_event *hwc = &event->hw;
 102
 103         if (flags & PERF_EF_RELOAD)
 104                 wrmsrl(hwc->event_base, (u64)local64_read(&hwc->prev_count));
 105
 106         hwc->state = 0;
 107         wrmsrl(hwc->config_base, (hwc->config | ARCH_PERFMON_EVENTSEL_ENABLE));
 108         perf_event_update_userpage(event);
 109 }
 110
 111 static void amd_uncore_stop(struct perf_event *event, int flags)
 112 {
 113         struct hw_perf_event *hwc = &event->hw;
 114
 115         wrmsrl(hwc->config_base, hwc->config);
 116         hwc->state |= PERF_HES_STOPPED;
 117
 118         if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
 119                 amd_uncore_read(event);
 120                 hwc->state |= PERF_HES_UPTODATE;
 121         }
 122 }
 123
 124 static int amd_uncore_add(struct perf_event *event, int flags)
 125 {
 126         int i;
 127         struct amd_uncore *uncore = event_to_amd_uncore(event);
 128         struct hw_perf_event *hwc = &event->hw;
 129
 130         /* are we already assigned? */
 131         if (hwc->idx != -1 && uncore->events[hwc->idx] == event)
 132                 goto out;
 133
 134         for (i = 0; i < uncore->num_counters; i++) {
 135                 if (uncore->events[i] == event) {
 136                         hwc->idx = i;
 137                         goto out;
 138                 }
 139         }
 140
 141         /* if not, take the first available counter */
 142         hwc->idx = -1;
 143         for (i = 0; i < uncore->num_counters; i++) {
 144                 if (cmpxchg(&uncore->events[i], NULL, event) == NULL) {
 145                         hwc->idx = i;
 146                         break;
 147                 }
 148         }
 149
 150 out:
 151         if (hwc->idx == -1)
 152                 return -EBUSY;
 153
 154         hwc->config_base = uncore->msr_base + (2 * hwc->idx);
 155         hwc->event_base = uncore->msr_base + 1 + (2 * hwc->idx);
 156         hwc->event_base_rdpmc = uncore->rdpmc_base + hwc->idx;
 157         hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
 158
 159         if (flags & PERF_EF_START)
 160                 amd_uncore_start(event, PERF_EF_RELOAD);
 161
 162         return 0;
 163 }
 164
 165 static void amd_uncore_del(struct perf_event *event, int flags)
 166 {
 167         int i;
 168         struct amd_uncore *uncore = event_to_amd_uncore(event);
 169         struct hw_perf_event *hwc = &event->hw;
 170
 171         amd_uncore_stop(event, PERF_EF_UPDATE);
 172
 173         for (i = 0; i < uncore->num_counters; i++) {
 174                 if (cmpxchg(&uncore->events[i], event, NULL) == event)
 175                         break;
 176         }
 177
 178         hwc->idx = -1;
 179 }
 180
 181 static int amd_uncore_event_init(struct perf_event *event)
 182 {
 183         struct amd_uncore *uncore;
 184         struct hw_perf_event *hwc = &event->hw;
 185
 186         if (event->attr.type != event->pmu->type)
 187                 return -ENOENT;
 188
 189         /*
 190          * NB and Last level cache counters (MSRs) are shared across all cores
 191          * that share the same NB / Last level cache. Interrupts can be directed
 192          * to a single target core, however, event counts generated by processes
 193          * running on other cores cannot be masked out. So we do not support
 194          * sampling and per-thread events.
 195          */
 196         if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
 197                 return -EINVAL;
 198
 199         /* NB and Last level cache counters do not have usr/os/guest/host bits */
 200         if (event->attr.exclude_user || event->attr.exclude_kernel ||
 201             event->attr.exclude_host || event->attr.exclude_guest)
 202                 return -EINVAL;
 203
 204         /* and we do not enable counter overflow interrupts */
 205         hwc->config = event->attr.config & AMD64_RAW_EVENT_MASK_NB;
 206         hwc->idx = -1;
 207
 208         if (event->cpu < 0)
 209                 return -EINVAL;
 210
 211         uncore = event_to_amd_uncore(event);
 212         if (!uncore)
 213                 return -ENODEV;
 214
 215         /*
 216          * since request can come in to any of the shared cores, we will remap
 217          * to a single common cpu.
 218          */
 219         event->cpu = uncore->cpu;
 220
 221         return 0;
 222 }
 223
 224 static ssize_t amd_uncore_attr_show_cpumask(struct device *dev,
 225                                             struct device_attribute *attr,
 226                                             char *buf)
 227 {
 228         cpumask_t *active_mask;
 229         struct pmu *pmu = dev_get_drvdata(dev);
 230
 231         if (pmu->type == amd_nb_pmu.type)
 232                 active_mask = &amd_nb_active_mask;
 233         else if (pmu->type == amd_llc_pmu.type)
 234                 active_mask = &amd_llc_active_mask;
 235         else
 236                 return 0;
 237
 238         return cpumap_print_to_pagebuf(true, buf, active_mask);
 239 }
 240 static DEVICE_ATTR(cpumask, S_IRUGO, amd_uncore_attr_show_cpumask, NULL);
 241
 242 static struct attribute *amd_uncore_attrs[] = {
 243         &dev_attr_cpumask.attr,
 244         NULL,
 245 };
 246
 247 static struct attribute_group amd_uncore_attr_group = {
 248         .attrs = amd_uncore_attrs,
 249 };
 250
 251 PMU_FORMAT_ATTR(event, "config:0-7,32-35");
 252 PMU_FORMAT_ATTR(umask, "config:8-15");
 253
 254 static struct attribute *amd_uncore_format_attr[] = {
 255         &format_attr_event.attr,
 256         &format_attr_umask.attr,
 257         NULL,
 258 };
 259
 260 static struct attribute_group amd_uncore_format_group = {
 261         .name = "format",
 262         .attrs = amd_uncore_format_attr,
 263 };
 264
 265 static const struct attribute_group *amd_uncore_attr_groups[] = {
 266         &amd_uncore_attr_group,
 267         &amd_uncore_format_group,
 268         NULL,
 269 };
 270
 271 static struct pmu amd_nb_pmu = {
 272         .task_ctx_nr    = perf_invalid_context,
 273         .attr_groups    = amd_uncore_attr_groups,
 274         .name           = "amd_nb",
 275         .event_init     = amd_uncore_event_init,
 276         .add            = amd_uncore_add,
 277         .del            = amd_uncore_del,
 278         .start          = amd_uncore_start,
 279         .stop           = amd_uncore_stop,
 280         .read           = amd_uncore_read,
 281 };
 282
 283 static struct pmu amd_llc_pmu = {
 284         .task_ctx_nr    = perf_invalid_context,
 285         .attr_groups    = amd_uncore_attr_groups,
 286         .name           = "amd_l2",
 287         .event_init     = amd_uncore_event_init,
 288         .add            = amd_uncore_add,
 289         .del            = amd_uncore_del,
 290         .start          = amd_uncore_start,
 291         .stop           = amd_uncore_stop,
 292         .read           = amd_uncore_read,
 293 };
 294
 295 static struct amd_uncore *amd_uncore_alloc(unsigned int cpu)
 296 {
 297         return kzalloc_node(sizeof(struct amd_uncore), GFP_KERNEL,
 298                         cpu_to_node(cpu));
 299 }
 300
 301 static int amd_uncore_cpu_up_prepare(unsigned int cpu)
 302 {
 303         struct amd_uncore *uncore_nb = NULL, *uncore_llc;
 304
 305         if (amd_uncore_nb) {
 306                 uncore_nb = amd_uncore_alloc(cpu);
 307                 if (!uncore_nb)
 308                         goto fail;
 309                 uncore_nb->cpu = cpu;
 310                 uncore_nb->num_counters = num_counters_nb;
 311                 uncore_nb->rdpmc_base = RDPMC_BASE_NB;
 312                 uncore_nb->msr_base = MSR_F15H_NB_PERF_CTL;
 313                 uncore_nb->active_mask = &amd_nb_active_mask;
 314                 uncore_nb->pmu = &amd_nb_pmu;
 315                 uncore_nb->id = -1;
 316                 *per_cpu_ptr(amd_uncore_nb, cpu) = uncore_nb;
 317         }
 318
 319         if (amd_uncore_llc) {
 320                 uncore_llc = amd_uncore_alloc(cpu);
 321                 if (!uncore_llc)
 322                         goto fail;
 323                 uncore_llc->cpu = cpu;
 324                 uncore_llc->num_counters = num_counters_llc;
 325                 uncore_llc->rdpmc_base = RDPMC_BASE_LLC;
 326                 uncore_llc->msr_base = MSR_F16H_L2I_PERF_CTL;
 327                 uncore_llc->active_mask = &amd_llc_active_mask;
 328                 uncore_llc->pmu = &amd_llc_pmu;
 329                 uncore_llc->id = -1;
 330                 *per_cpu_ptr(amd_uncore_llc, cpu) = uncore_llc;
 331         }
 332
 333         return 0;
 334
 335 fail:
 336         if (amd_uncore_nb)
 337                 *per_cpu_ptr(amd_uncore_nb, cpu) = NULL;
 338         kfree(uncore_nb);
 339         return -ENOMEM;
 340 }
 341
 342 static struct amd_uncore *
 343 amd_uncore_find_online_sibling(struct amd_uncore *this,
 344                                struct amd_uncore * __percpu *uncores)
 345 {
 346         unsigned int cpu;
 347         struct amd_uncore *that;
 348
 349         for_each_online_cpu(cpu) {
 350                 that = *per_cpu_ptr(uncores, cpu);
 351
 352                 if (!that)
 353                         continue;
 354
 355                 if (this == that)
 356                         continue;
 357
 358                 if (this->id == that->id) {
 359                         hlist_add_head(&this->node, &uncore_unused_list);
 360                         this = that;
 361                         break;
 362                 }
 363         }
 364
 365         this->refcnt++;
 366         return this;
 367 }
 368
 369 static int amd_uncore_cpu_starting(unsigned int cpu)
 370 {
 371         unsigned int eax, ebx, ecx, edx;
 372         struct amd_uncore *uncore;
 373
 374         if (amd_uncore_nb) {
 375                 uncore = *per_cpu_ptr(amd_uncore_nb, cpu);
 376                 cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
 377                 uncore->id = ecx & 0xff;
 378
 379                 uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_nb);
 380                 *per_cpu_ptr(amd_uncore_nb, cpu) = uncore;
 381         }
 382
 383         if (amd_uncore_llc) {
 384                 unsigned int apicid = cpu_data(cpu).apicid;
 385                 unsigned int nshared;
 386
 387                 uncore = *per_cpu_ptr(amd_uncore_llc, cpu);
 388                 cpuid_count(0x8000001d, 2, &eax, &ebx, &ecx, &edx);
 389                 nshared = ((eax >> 14) & 0xfff) + 1;
 390                 uncore->id = apicid - (apicid % nshared);
 391
 392                 uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_llc);
 393                 *per_cpu_ptr(amd_uncore_llc, cpu) = uncore;
 394         }
 395
 396         return 0;
 397 }
 398
 399 static void uncore_clean_online(void)
 400 {
 401         struct amd_uncore *uncore;
 402         struct hlist_node *n;
 403
 404         hlist_for_each_entry_safe(uncore, n, &uncore_unused_list, node) {
 405                 hlist_del(&uncore->node);
 406                 kfree(uncore);
 407         }
 408 }
 409
 410 static void uncore_online(unsigned int cpu,
 411                           struct amd_uncore * __percpu *uncores)
 412 {
 413         struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu);
 414
 415         uncore_clean_online();
 416
 417         if (cpu == uncore->cpu)
 418                 cpumask_set_cpu(cpu, uncore->active_mask);
 419 }
 420
 421 static int amd_uncore_cpu_online(unsigned int cpu)
 422 {
 423         if (amd_uncore_nb)
 424                 uncore_online(cpu, amd_uncore_nb);
 425
 426         if (amd_uncore_llc)
 427                 uncore_online(cpu, amd_uncore_llc);
 428
 429         return 0;
 430 }
 431
 432 static void uncore_down_prepare(unsigned int cpu,
 433                                 struct amd_uncore * __percpu *uncores)
 434 {
 435         unsigned int i;
 436         struct amd_uncore *this = *per_cpu_ptr(uncores, cpu);
 437
 438         if (this->cpu != cpu)
 439                 return;
 440
 441         /* this cpu is going down, migrate to a shared sibling if possible */
 442         for_each_online_cpu(i) {
 443                 struct amd_uncore *that = *per_cpu_ptr(uncores, i);
 444
 445                 if (cpu == i)
 446                         continue;
 447
 448                 if (this == that) {
 449                         perf_pmu_migrate_context(this->pmu, cpu, i);
 450                         cpumask_clear_cpu(cpu, that->active_mask);
 451                         cpumask_set_cpu(i, that->active_mask);
 452                         that->cpu = i;
 453                         break;
 454                 }
 455         }
 456 }
 457
 458 static int amd_uncore_cpu_down_prepare(unsigned int cpu)
 459 {
 460         if (amd_uncore_nb)
 461                 uncore_down_prepare(cpu, amd_uncore_nb);
 462
 463         if (amd_uncore_llc)
 464                 uncore_down_prepare(cpu, amd_uncore_llc);
 465
 466         return 0;
 467 }
 468
 469 static void uncore_dead(unsigned int cpu, struct amd_uncore * __percpu *uncores)
 470 {
 471         struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu);
 472
 473         if (cpu == uncore->cpu)
 474                 cpumask_clear_cpu(cpu, uncore->active_mask);
 475
 476         if (!--uncore->refcnt)
 477                 kfree(uncore);
 478         *per_cpu_ptr(uncores, cpu) = NULL;
 479 }
 480
 481 static int amd_uncore_cpu_dead(unsigned int cpu)
 482 {
 483         if (amd_uncore_nb)
 484                 uncore_dead(cpu, amd_uncore_nb);
 485
 486         if (amd_uncore_llc)
 487                 uncore_dead(cpu, amd_uncore_llc);
 488
 489         return 0;
 490 }
 491
 492 static int __init amd_uncore_init(void)
 493 {
 494         int ret = -ENODEV;
 495
 496         if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
 497                 goto fail_nodev;
 498
 499         switch(boot_cpu_data.x86) {
 500                 case 23:
 501                         /* Family 17h: */
 502                         num_counters_nb = NUM_COUNTERS_NB;
 503                         num_counters_llc = NUM_COUNTERS_L3;
 504                         break;
 505                 case 22:
 506                         /* Family 16h - may change: */
 507                         num_counters_nb = NUM_COUNTERS_NB;
 508                         num_counters_llc = NUM_COUNTERS_L2;
 509                         break;
 510                 default:
 511                         /*
 512                          * All prior families have the same number of
 513                          * NorthBridge and Last Level Cache counters
 514                          */
 515                         num_counters_nb = NUM_COUNTERS_NB;
 516                         num_counters_llc = NUM_COUNTERS_L2;
 517                         break;
 518         }
 519
 520         if (!boot_cpu_has(X86_FEATURE_TOPOEXT))
 521                 goto fail_nodev;
 522
 523         if (boot_cpu_has(X86_FEATURE_PERFCTR_NB)) {
 524                 amd_uncore_nb = alloc_percpu(struct amd_uncore *);
 525                 if (!amd_uncore_nb) {
 526                         ret = -ENOMEM;
 527                         goto fail_nb;
 528                 }
 529                 ret = perf_pmu_register(&amd_nb_pmu, amd_nb_pmu.name, -1);
 530                 if (ret)
 531                         goto fail_nb;
 532
 533                 pr_info("perf: AMD NB counters detected\n");
 534                 ret = 0;
 535         }
 536
 537         if (boot_cpu_has(X86_FEATURE_PERFCTR_L2)) {
 538                 amd_uncore_llc = alloc_percpu(struct amd_uncore *);
 539                 if (!amd_uncore_llc) {
 540                         ret = -ENOMEM;
 541                         goto fail_llc;
 542                 }
 543                 ret = perf_pmu_register(&amd_llc_pmu, amd_llc_pmu.name, -1);
 544                 if (ret)
 545                         goto fail_llc;
 546
 547                 pr_info("perf: AMD LLC counters detected\n");
 548                 ret = 0;
 549         }
 550
 551         /*
 552          * Install callbacks. Core will call them for each online cpu.
 553          */
 554         if (cpuhp_setup_state(CPUHP_PERF_X86_AMD_UNCORE_PREP,
 555                               "perf/x86/amd/uncore:prepare",
 556                               amd_uncore_cpu_up_prepare, amd_uncore_cpu_dead))
 557                 goto fail_llc;
 558
 559         if (cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
 560                               "perf/x86/amd/uncore:starting",
 561                               amd_uncore_cpu_starting, NULL))
 562                 goto fail_prep;
 563         if (cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
 564                               "perf/x86/amd/uncore:online",
 565                               amd_uncore_cpu_online,
 566                               amd_uncore_cpu_down_prepare))
 567                 goto fail_start;
 568         return 0;
 569
 570 fail_start:
 571         cpuhp_remove_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING);
 572 fail_prep:
 573         cpuhp_remove_state(CPUHP_PERF_X86_AMD_UNCORE_PREP);
 574 fail_llc:
 575         if (boot_cpu_has(X86_FEATURE_PERFCTR_NB))
 576                 perf_pmu_unregister(&amd_nb_pmu);
 577         if (amd_uncore_llc)
 578                 free_percpu(amd_uncore_llc);
 579 fail_nb:
 580         if (amd_uncore_nb)
 581                 free_percpu(amd_uncore_nb);
 582
 583 fail_nodev:
 584         return ret;
 585 }
 586 device_initcall(amd_uncore_init);