arch/x86/kernel/cpu/perf_event_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 MAX_COUNTERS            NUM_COUNTERS_NB
  26
  27 #define RDPMC_BASE_NB           6
  28 #define RDPMC_BASE_L2           10
  29
  30 #define COUNTER_SHIFT           16
  31
  32 struct amd_uncore {
  33         int id;
  34         int refcnt;
  35         int cpu;
  36         int num_counters;
  37         int rdpmc_base;
  38         u32 msr_base;
  39         cpumask_t *active_mask;
  40         struct pmu *pmu;
  41         struct perf_event *events[MAX_COUNTERS];
  42         struct amd_uncore *free_when_cpu_online;
  43 };
  44
  45 static struct amd_uncore * __percpu *amd_uncore_nb;
  46 static struct amd_uncore * __percpu *amd_uncore_l2;
  47
  48 static struct pmu amd_nb_pmu;
  49 static struct pmu amd_l2_pmu;
  50
  51 static cpumask_t amd_nb_active_mask;
  52 static cpumask_t amd_l2_active_mask;
  53
  54 static bool is_nb_event(struct perf_event *event)
  55 {
  56         return event->pmu->type == amd_nb_pmu.type;
  57 }
  58
  59 static bool is_l2_event(struct perf_event *event)
  60 {
  61         return event->pmu->type == amd_l2_pmu.type;
  62 }
  63
  64 static struct amd_uncore *event_to_amd_uncore(struct perf_event *event)
  65 {
  66         if (is_nb_event(event) && amd_uncore_nb)
  67                 return *per_cpu_ptr(amd_uncore_nb, event->cpu);
  68         else if (is_l2_event(event) && amd_uncore_l2)
  69                 return *per_cpu_ptr(amd_uncore_l2, event->cpu);
  70
  71         return NULL;
  72 }
  73
  74 static void amd_uncore_read(struct perf_event *event)
  75 {
  76         struct hw_perf_event *hwc = &event->hw;
  77         u64 prev, new;
  78         s64 delta;
  79
  80         /*
  81          * since we do not enable counter overflow interrupts,
  82          * we do not have to worry about prev_count changing on us
  83          */
  84
  85         prev = local64_read(&hwc->prev_count);
  86         rdpmcl(hwc->event_base_rdpmc, new);
  87         local64_set(&hwc->prev_count, new);
  88         delta = (new << COUNTER_SHIFT) - (prev << COUNTER_SHIFT);
  89         delta >>= COUNTER_SHIFT;
  90         local64_add(delta, &event->count);
  91 }
  92
  93 static void amd_uncore_start(struct perf_event *event, int flags)
  94 {
  95         struct hw_perf_event *hwc = &event->hw;
  96
  97         if (flags & PERF_EF_RELOAD)
  98                 wrmsrl(hwc->event_base, (u64)local64_read(&hwc->prev_count));
  99
 100         hwc->state = 0;
 101         wrmsrl(hwc->config_base, (hwc->config | ARCH_PERFMON_EVENTSEL_ENABLE));
 102         perf_event_update_userpage(event);
 103 }
 104
 105 static void amd_uncore_stop(struct perf_event *event, int flags)
 106 {
 107         struct hw_perf_event *hwc = &event->hw;
 108
 109         wrmsrl(hwc->config_base, hwc->config);
 110         hwc->state |= PERF_HES_STOPPED;
 111
 112         if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
 113                 amd_uncore_read(event);
 114                 hwc->state |= PERF_HES_UPTODATE;
 115         }
 116 }
 117
 118 static int amd_uncore_add(struct perf_event *event, int flags)
 119 {
 120         int i;
 121         struct amd_uncore *uncore = event_to_amd_uncore(event);
 122         struct hw_perf_event *hwc = &event->hw;
 123
 124         /* are we already assigned? */
 125         if (hwc->idx != -1 && uncore->events[hwc->idx] == event)
 126                 goto out;
 127
 128         for (i = 0; i < uncore->num_counters; i++) {
 129                 if (uncore->events[i] == event) {
 130                         hwc->idx = i;
 131                         goto out;
 132                 }
 133         }
 134
 135         /* if not, take the first available counter */
 136         hwc->idx = -1;
 137         for (i = 0; i < uncore->num_counters; i++) {
 138                 if (cmpxchg(&uncore->events[i], NULL, event) == NULL) {
 139                         hwc->idx = i;
 140                         break;
 141                 }
 142         }
 143
 144 out:
 145         if (hwc->idx == -1)
 146                 return -EBUSY;
 147
 148         hwc->config_base = uncore->msr_base + (2 * hwc->idx);
 149         hwc->event_base = uncore->msr_base + 1 + (2 * hwc->idx);
 150         hwc->event_base_rdpmc = uncore->rdpmc_base + hwc->idx;
 151         hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
 152
 153         if (flags & PERF_EF_START)
 154                 amd_uncore_start(event, PERF_EF_RELOAD);
 155
 156         return 0;
 157 }
 158
 159 static void amd_uncore_del(struct perf_event *event, int flags)
 160 {
 161         int i;
 162         struct amd_uncore *uncore = event_to_amd_uncore(event);
 163         struct hw_perf_event *hwc = &event->hw;
 164
 165         amd_uncore_stop(event, PERF_EF_UPDATE);
 166
 167         for (i = 0; i < uncore->num_counters; i++) {
 168                 if (cmpxchg(&uncore->events[i], event, NULL) == event)
 169                         break;
 170         }
 171
 172         hwc->idx = -1;
 173 }
 174
 175 static int amd_uncore_event_init(struct perf_event *event)
 176 {
 177         struct amd_uncore *uncore;
 178         struct hw_perf_event *hwc = &event->hw;
 179
 180         if (event->attr.type != event->pmu->type)
 181                 return -ENOENT;
 182
 183         /*
 184          * NB and L2 counters (MSRs) are shared across all cores that share the
 185          * same NB / L2 cache. Interrupts can be directed to a single target
 186          * core, however, event counts generated by processes running on other
 187          * cores cannot be masked out. So we do not support sampling and
 188          * per-thread events.
 189          */
 190         if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
 191                 return -EINVAL;
 192
 193         /* NB and L2 counters do not have usr/os/guest/host bits */
 194         if (event->attr.exclude_user || event->attr.exclude_kernel ||
 195             event->attr.exclude_host || event->attr.exclude_guest)
 196                 return -EINVAL;
 197
 198         /* and we do not enable counter overflow interrupts */
 199         hwc->config = event->attr.config & AMD64_RAW_EVENT_MASK_NB;
 200         hwc->idx = -1;
 201
 202         if (event->cpu < 0)
 203                 return -EINVAL;
 204
 205         uncore = event_to_amd_uncore(event);
 206         if (!uncore)
 207                 return -ENODEV;
 208
 209         /*
 210          * since request can come in to any of the shared cores, we will remap
 211          * to a single common cpu.
 212          */
 213         event->cpu = uncore->cpu;
 214
 215         return 0;
 216 }
 217
 218 static ssize_t amd_uncore_attr_show_cpumask(struct device *dev,
 219                                             struct device_attribute *attr,
 220                                             char *buf)
 221 {
 222         cpumask_t *active_mask;
 223         struct pmu *pmu = dev_get_drvdata(dev);
 224
 225         if (pmu->type == amd_nb_pmu.type)
 226                 active_mask = &amd_nb_active_mask;
 227         else if (pmu->type == amd_l2_pmu.type)
 228                 active_mask = &amd_l2_active_mask;
 229         else
 230                 return 0;
 231
 232         return cpumap_print_to_pagebuf(true, buf, active_mask);
 233 }
 234 static DEVICE_ATTR(cpumask, S_IRUGO, amd_uncore_attr_show_cpumask, NULL);
 235
 236 static struct attribute *amd_uncore_attrs[] = {
 237         &dev_attr_cpumask.attr,
 238         NULL,
 239 };
 240
 241 static struct attribute_group amd_uncore_attr_group = {
 242         .attrs = amd_uncore_attrs,
 243 };
 244
 245 PMU_FORMAT_ATTR(event, "config:0-7,32-35");
 246 PMU_FORMAT_ATTR(umask, "config:8-15");
 247
 248 static struct attribute *amd_uncore_format_attr[] = {
 249         &format_attr_event.attr,
 250         &format_attr_umask.attr,
 251         NULL,
 252 };
 253
 254 static struct attribute_group amd_uncore_format_group = {
 255         .name = "format",
 256         .attrs = amd_uncore_format_attr,
 257 };
 258
 259 static const struct attribute_group *amd_uncore_attr_groups[] = {
 260         &amd_uncore_attr_group,
 261         &amd_uncore_format_group,
 262         NULL,
 263 };
 264
 265 static struct pmu amd_nb_pmu = {
 266         .attr_groups    = amd_uncore_attr_groups,
 267         .name           = "amd_nb",
 268         .event_init     = amd_uncore_event_init,
 269         .add            = amd_uncore_add,
 270         .del            = amd_uncore_del,
 271         .start          = amd_uncore_start,
 272         .stop           = amd_uncore_stop,
 273         .read           = amd_uncore_read,
 274 };
 275
 276 static struct pmu amd_l2_pmu = {
 277         .attr_groups    = amd_uncore_attr_groups,
 278         .name           = "amd_l2",
 279         .event_init     = amd_uncore_event_init,
 280         .add            = amd_uncore_add,
 281         .del            = amd_uncore_del,
 282         .start          = amd_uncore_start,
 283         .stop           = amd_uncore_stop,
 284         .read           = amd_uncore_read,
 285 };
 286
 287 static struct amd_uncore *amd_uncore_alloc(unsigned int cpu)
 288 {
 289         return kzalloc_node(sizeof(struct amd_uncore), GFP_KERNEL,
 290                         cpu_to_node(cpu));
 291 }
 292
 293 static int amd_uncore_cpu_up_prepare(unsigned int cpu)
 294 {
 295         struct amd_uncore *uncore_nb = NULL, *uncore_l2;
 296
 297         if (amd_uncore_nb) {
 298                 uncore_nb = amd_uncore_alloc(cpu);
 299                 if (!uncore_nb)
 300                         goto fail;
 301                 uncore_nb->cpu = cpu;
 302                 uncore_nb->num_counters = NUM_COUNTERS_NB;
 303                 uncore_nb->rdpmc_base = RDPMC_BASE_NB;
 304                 uncore_nb->msr_base = MSR_F15H_NB_PERF_CTL;
 305                 uncore_nb->active_mask = &amd_nb_active_mask;
 306                 uncore_nb->pmu = &amd_nb_pmu;
 307                 *per_cpu_ptr(amd_uncore_nb, cpu) = uncore_nb;
 308         }
 309
 310         if (amd_uncore_l2) {
 311                 uncore_l2 = amd_uncore_alloc(cpu);
 312                 if (!uncore_l2)
 313                         goto fail;
 314                 uncore_l2->cpu = cpu;
 315                 uncore_l2->num_counters = NUM_COUNTERS_L2;
 316                 uncore_l2->rdpmc_base = RDPMC_BASE_L2;
 317                 uncore_l2->msr_base = MSR_F16H_L2I_PERF_CTL;
 318                 uncore_l2->active_mask = &amd_l2_active_mask;
 319                 uncore_l2->pmu = &amd_l2_pmu;
 320                 *per_cpu_ptr(amd_uncore_l2, cpu) = uncore_l2;
 321         }
 322
 323         return 0;
 324
 325 fail:
 326         kfree(uncore_nb);
 327         return -ENOMEM;
 328 }
 329
 330 static struct amd_uncore *
 331 amd_uncore_find_online_sibling(struct amd_uncore *this,
 332                                struct amd_uncore * __percpu *uncores)
 333 {
 334         unsigned int cpu;
 335         struct amd_uncore *that;
 336
 337         for_each_online_cpu(cpu) {
 338                 that = *per_cpu_ptr(uncores, cpu);
 339
 340                 if (!that)
 341                         continue;
 342
 343                 if (this == that)
 344                         continue;
 345
 346                 if (this->id == that->id) {
 347                         that->free_when_cpu_online = this;
 348                         this = that;
 349                         break;
 350                 }
 351         }
 352
 353         this->refcnt++;
 354         return this;
 355 }
 356
 357 static void amd_uncore_cpu_starting(unsigned int cpu)
 358 {
 359         unsigned int eax, ebx, ecx, edx;
 360         struct amd_uncore *uncore;
 361
 362         if (amd_uncore_nb) {
 363                 uncore = *per_cpu_ptr(amd_uncore_nb, cpu);
 364                 cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
 365                 uncore->id = ecx & 0xff;
 366
 367                 uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_nb);
 368                 *per_cpu_ptr(amd_uncore_nb, cpu) = uncore;
 369         }
 370
 371         if (amd_uncore_l2) {
 372                 unsigned int apicid = cpu_data(cpu).apicid;
 373                 unsigned int nshared;
 374
 375                 uncore = *per_cpu_ptr(amd_uncore_l2, cpu);
 376                 cpuid_count(0x8000001d, 2, &eax, &ebx, &ecx, &edx);
 377                 nshared = ((eax >> 14) & 0xfff) + 1;
 378                 uncore->id = apicid - (apicid % nshared);
 379
 380                 uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_l2);
 381                 *per_cpu_ptr(amd_uncore_l2, cpu) = uncore;
 382         }
 383 }
 384
 385 static void uncore_online(unsigned int cpu,
 386                           struct amd_uncore * __percpu *uncores)
 387 {
 388         struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu);
 389
 390         kfree(uncore->free_when_cpu_online);
 391         uncore->free_when_cpu_online = NULL;
 392
 393         if (cpu == uncore->cpu)
 394                 cpumask_set_cpu(cpu, uncore->active_mask);
 395 }
 396
 397 static void amd_uncore_cpu_online(unsigned int cpu)
 398 {
 399         if (amd_uncore_nb)
 400                 uncore_online(cpu, amd_uncore_nb);
 401
 402         if (amd_uncore_l2)
 403                 uncore_online(cpu, amd_uncore_l2);
 404 }
 405
 406 static void uncore_down_prepare(unsigned int cpu,
 407                                 struct amd_uncore * __percpu *uncores)
 408 {
 409         unsigned int i;
 410         struct amd_uncore *this = *per_cpu_ptr(uncores, cpu);
 411
 412         if (this->cpu != cpu)
 413                 return;
 414
 415         /* this cpu is going down, migrate to a shared sibling if possible */
 416         for_each_online_cpu(i) {
 417                 struct amd_uncore *that = *per_cpu_ptr(uncores, i);
 418
 419                 if (cpu == i)
 420                         continue;
 421
 422                 if (this == that) {
 423                         perf_pmu_migrate_context(this->pmu, cpu, i);
 424                         cpumask_clear_cpu(cpu, that->active_mask);
 425                         cpumask_set_cpu(i, that->active_mask);
 426                         that->cpu = i;
 427                         break;
 428                 }
 429         }
 430 }
 431
 432 static void amd_uncore_cpu_down_prepare(unsigned int cpu)
 433 {
 434         if (amd_uncore_nb)
 435                 uncore_down_prepare(cpu, amd_uncore_nb);
 436
 437         if (amd_uncore_l2)
 438                 uncore_down_prepare(cpu, amd_uncore_l2);
 439 }
 440
 441 static void uncore_dead(unsigned int cpu, struct amd_uncore * __percpu *uncores)
 442 {
 443         struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu);
 444
 445         if (cpu == uncore->cpu)
 446                 cpumask_clear_cpu(cpu, uncore->active_mask);
 447
 448         if (!--uncore->refcnt)
 449                 kfree(uncore);
 450         *per_cpu_ptr(uncores, cpu) = NULL;
 451 }
 452
 453 static void amd_uncore_cpu_dead(unsigned int cpu)
 454 {
 455         if (amd_uncore_nb)
 456                 uncore_dead(cpu, amd_uncore_nb);
 457
 458         if (amd_uncore_l2)
 459                 uncore_dead(cpu, amd_uncore_l2);
 460 }
 461
 462 static int
 463 amd_uncore_cpu_notifier(struct notifier_block *self, unsigned long action,
 464                         void *hcpu)
 465 {
 466         unsigned int cpu = (long)hcpu;
 467
 468         switch (action & ~CPU_TASKS_FROZEN) {
 469         case CPU_UP_PREPARE:
 470                 if (amd_uncore_cpu_up_prepare(cpu))
 471                         return notifier_from_errno(-ENOMEM);
 472                 break;
 473
 474         case CPU_STARTING:
 475                 amd_uncore_cpu_starting(cpu);
 476                 break;
 477
 478         case CPU_ONLINE:
 479                 amd_uncore_cpu_online(cpu);
 480                 break;
 481
 482         case CPU_DOWN_PREPARE:
 483                 amd_uncore_cpu_down_prepare(cpu);
 484                 break;
 485
 486         case CPU_UP_CANCELED:
 487         case CPU_DEAD:
 488                 amd_uncore_cpu_dead(cpu);
 489                 break;
 490
 491         default:
 492                 break;
 493         }
 494
 495         return NOTIFY_OK;
 496 }
 497
 498 static struct notifier_block amd_uncore_cpu_notifier_block = {
 499         .notifier_call  = amd_uncore_cpu_notifier,
 500         .priority       = CPU_PRI_PERF + 1,
 501 };
 502
 503 static void __init init_cpu_already_online(void *dummy)
 504 {
 505         unsigned int cpu = smp_processor_id();
 506
 507         amd_uncore_cpu_starting(cpu);
 508         amd_uncore_cpu_online(cpu);
 509 }
 510
 511 static void cleanup_cpu_online(void *dummy)
 512 {
 513         unsigned int cpu = smp_processor_id();
 514
 515         amd_uncore_cpu_dead(cpu);
 516 }
 517
 518 static int __init amd_uncore_init(void)
 519 {
 520         unsigned int cpu, cpu2;
 521         int ret = -ENODEV;
 522
 523         if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
 524                 goto fail_nodev;
 525
 526         if (!boot_cpu_has(X86_FEATURE_TOPOEXT))
 527                 goto fail_nodev;
 528
 529         if (boot_cpu_has(X86_FEATURE_PERFCTR_NB)) {
 530                 amd_uncore_nb = alloc_percpu(struct amd_uncore *);
 531                 if (!amd_uncore_nb) {
 532                         ret = -ENOMEM;
 533                         goto fail_nb;
 534                 }
 535                 ret = perf_pmu_register(&amd_nb_pmu, amd_nb_pmu.name, -1);
 536                 if (ret)
 537                         goto fail_nb;
 538
 539                 printk(KERN_INFO "perf: AMD NB counters detected\n");
 540                 ret = 0;
 541         }
 542
 543         if (boot_cpu_has(X86_FEATURE_PERFCTR_L2)) {
 544                 amd_uncore_l2 = alloc_percpu(struct amd_uncore *);
 545                 if (!amd_uncore_l2) {
 546                         ret = -ENOMEM;
 547                         goto fail_l2;
 548                 }
 549                 ret = perf_pmu_register(&amd_l2_pmu, amd_l2_pmu.name, -1);
 550                 if (ret)
 551                         goto fail_l2;
 552
 553                 printk(KERN_INFO "perf: AMD L2I counters detected\n");
 554                 ret = 0;
 555         }
 556
 557         if (ret)
 558                 goto fail_nodev;
 559
 560         cpu_notifier_register_begin();
 561
 562         /* init cpus already online before registering for hotplug notifier */
 563         for_each_online_cpu(cpu) {
 564                 ret = amd_uncore_cpu_up_prepare(cpu);
 565                 if (ret)
 566                         goto fail_online;
 567                 smp_call_function_single(cpu, init_cpu_already_online, NULL, 1);
 568         }
 569
 570         __register_cpu_notifier(&amd_uncore_cpu_notifier_block);
 571         cpu_notifier_register_done();
 572
 573         return 0;
 574
 575
 576 fail_online:
 577         for_each_online_cpu(cpu2) {
 578                 if (cpu2 == cpu)
 579                         break;
 580                 smp_call_function_single(cpu, cleanup_cpu_online, NULL, 1);
 581         }
 582         cpu_notifier_register_done();
 583
 584         /* amd_uncore_nb/l2 should have been freed by cleanup_cpu_online */
 585         amd_uncore_nb = amd_uncore_l2 = NULL;
 586
 587         if (boot_cpu_has(X86_FEATURE_PERFCTR_L2))
 588                 perf_pmu_unregister(&amd_l2_pmu);
 589 fail_l2:
 590         if (boot_cpu_has(X86_FEATURE_PERFCTR_NB))
 591                 perf_pmu_unregister(&amd_nb_pmu);
 592         if (amd_uncore_l2)
 593                 free_percpu(amd_uncore_l2);
 594 fail_nb:
 595         if (amd_uncore_nb)
 596                 free_percpu(amd_uncore_nb);
 597
 598 fail_nodev:
 599         return ret;
 600 }
 601 device_initcall(amd_uncore_init);