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 /*
 252  * Similar to PMU_FORMAT_ATTR but allowing for format_attr to be assigned based
 253  * on family
 254  */
 255 #define AMD_FORMAT_ATTR(_dev, _name, _format)                                \
 256 static ssize_t                                                               \
 257 _dev##_show##_name(struct device *dev,                                       \
 258                 struct device_attribute *attr,                               \
 259                 char *page)                                                  \
 260 {                                                                            \
 261         BUILD_BUG_ON(sizeof(_format) >= PAGE_SIZE);                          \
 262         return sprintf(page, _format "\n");                                  \
 263 }                                                                            \
 264 static struct device_attribute format_attr_##_dev##_name = __ATTR_RO(_dev);
 265
 266 /* Used for each uncore counter type */
 267 #define AMD_ATTRIBUTE(_name)                                                 \
 268 static struct attribute *amd_uncore_format_attr_##_name[] = {                \
 269         &format_attr_event_##_name.attr,                                     \
 270         &format_attr_umask.attr,                                             \
 271         NULL,                                                                \
 272 };                                                                           \
 273 static struct attribute_group amd_uncore_format_group_##_name = {            \
 274         .name = "format",                                                    \
 275         .attrs = amd_uncore_format_attr_##_name,                             \
 276 };                                                                           \
 277 static const struct attribute_group *amd_uncore_attr_groups_##_name[] = {    \
 278         &amd_uncore_attr_group,                                              \
 279         &amd_uncore_format_group_##_name,                                    \
 280         NULL,                                                                \
 281 };
 282
 283 AMD_FORMAT_ATTR(event, , "config:0-7,32-35");
 284 AMD_FORMAT_ATTR(umask, , "config:8-15");
 285 AMD_FORMAT_ATTR(event, _df, "config:0-7,32-35,59-60");
 286 AMD_FORMAT_ATTR(event, _l3, "config:0-7");
 287 AMD_ATTRIBUTE(df);
 288 AMD_ATTRIBUTE(l3);
 289
 290 static struct pmu amd_nb_pmu = {
 291         .task_ctx_nr    = perf_invalid_context,
 292         .event_init     = amd_uncore_event_init,
 293         .add            = amd_uncore_add,
 294         .del            = amd_uncore_del,
 295         .start          = amd_uncore_start,
 296         .stop           = amd_uncore_stop,
 297         .read           = amd_uncore_read,
 298 };
 299
 300 static struct pmu amd_llc_pmu = {
 301         .task_ctx_nr    = perf_invalid_context,
 302         .event_init     = amd_uncore_event_init,
 303         .add            = amd_uncore_add,
 304         .del            = amd_uncore_del,
 305         .start          = amd_uncore_start,
 306         .stop           = amd_uncore_stop,
 307         .read           = amd_uncore_read,
 308 };
 309
 310 static struct amd_uncore *amd_uncore_alloc(unsigned int cpu)
 311 {
 312         return kzalloc_node(sizeof(struct amd_uncore), GFP_KERNEL,
 313                         cpu_to_node(cpu));
 314 }
 315
 316 static int amd_uncore_cpu_up_prepare(unsigned int cpu)
 317 {
 318         struct amd_uncore *uncore_nb = NULL, *uncore_llc;
 319
 320         if (amd_uncore_nb) {
 321                 uncore_nb = amd_uncore_alloc(cpu);
 322                 if (!uncore_nb)
 323                         goto fail;
 324                 uncore_nb->cpu = cpu;
 325                 uncore_nb->num_counters = num_counters_nb;
 326                 uncore_nb->rdpmc_base = RDPMC_BASE_NB;
 327                 uncore_nb->msr_base = MSR_F15H_NB_PERF_CTL;
 328                 uncore_nb->active_mask = &amd_nb_active_mask;
 329                 uncore_nb->pmu = &amd_nb_pmu;
 330                 uncore_nb->id = -1;
 331                 *per_cpu_ptr(amd_uncore_nb, cpu) = uncore_nb;
 332         }
 333
 334         if (amd_uncore_llc) {
 335                 uncore_llc = amd_uncore_alloc(cpu);
 336                 if (!uncore_llc)
 337                         goto fail;
 338                 uncore_llc->cpu = cpu;
 339                 uncore_llc->num_counters = num_counters_llc;
 340                 uncore_llc->rdpmc_base = RDPMC_BASE_LLC;
 341                 uncore_llc->msr_base = MSR_F16H_L2I_PERF_CTL;
 342                 uncore_llc->active_mask = &amd_llc_active_mask;
 343                 uncore_llc->pmu = &amd_llc_pmu;
 344                 uncore_llc->id = -1;
 345                 *per_cpu_ptr(amd_uncore_llc, cpu) = uncore_llc;
 346         }
 347
 348         return 0;
 349
 350 fail:
 351         if (amd_uncore_nb)
 352                 *per_cpu_ptr(amd_uncore_nb, cpu) = NULL;
 353         kfree(uncore_nb);
 354         return -ENOMEM;
 355 }
 356
 357 static struct amd_uncore *
 358 amd_uncore_find_online_sibling(struct amd_uncore *this,
 359                                struct amd_uncore * __percpu *uncores)
 360 {
 361         unsigned int cpu;
 362         struct amd_uncore *that;
 363
 364         for_each_online_cpu(cpu) {
 365                 that = *per_cpu_ptr(uncores, cpu);
 366
 367                 if (!that)
 368                         continue;
 369
 370                 if (this == that)
 371                         continue;
 372
 373                 if (this->id == that->id) {
 374                         hlist_add_head(&this->node, &uncore_unused_list);
 375                         this = that;
 376                         break;
 377                 }
 378         }
 379
 380         this->refcnt++;
 381         return this;
 382 }
 383
 384 static int amd_uncore_cpu_starting(unsigned int cpu)
 385 {
 386         unsigned int eax, ebx, ecx, edx;
 387         struct amd_uncore *uncore;
 388
 389         if (amd_uncore_nb) {
 390                 uncore = *per_cpu_ptr(amd_uncore_nb, cpu);
 391                 cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
 392                 uncore->id = ecx & 0xff;
 393
 394                 uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_nb);
 395                 *per_cpu_ptr(amd_uncore_nb, cpu) = uncore;
 396         }
 397
 398         if (amd_uncore_llc) {
 399                 unsigned int apicid = cpu_data(cpu).apicid;
 400                 unsigned int nshared;
 401
 402                 uncore = *per_cpu_ptr(amd_uncore_llc, cpu);
 403                 cpuid_count(0x8000001d, 2, &eax, &ebx, &ecx, &edx);
 404                 nshared = ((eax >> 14) & 0xfff) + 1;
 405                 uncore->id = apicid - (apicid % nshared);
 406
 407                 uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_llc);
 408                 *per_cpu_ptr(amd_uncore_llc, cpu) = uncore;
 409         }
 410
 411         return 0;
 412 }
 413
 414 static void uncore_clean_online(void)
 415 {
 416         struct amd_uncore *uncore;
 417         struct hlist_node *n;
 418
 419         hlist_for_each_entry_safe(uncore, n, &uncore_unused_list, node) {
 420                 hlist_del(&uncore->node);
 421                 kfree(uncore);
 422         }
 423 }
 424
 425 static void uncore_online(unsigned int cpu,
 426                           struct amd_uncore * __percpu *uncores)
 427 {
 428         struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu);
 429
 430         uncore_clean_online();
 431
 432         if (cpu == uncore->cpu)
 433                 cpumask_set_cpu(cpu, uncore->active_mask);
 434 }
 435
 436 static int amd_uncore_cpu_online(unsigned int cpu)
 437 {
 438         if (amd_uncore_nb)
 439                 uncore_online(cpu, amd_uncore_nb);
 440
 441         if (amd_uncore_llc)
 442                 uncore_online(cpu, amd_uncore_llc);
 443
 444         return 0;
 445 }
 446
 447 static void uncore_down_prepare(unsigned int cpu,
 448                                 struct amd_uncore * __percpu *uncores)
 449 {
 450         unsigned int i;
 451         struct amd_uncore *this = *per_cpu_ptr(uncores, cpu);
 452
 453         if (this->cpu != cpu)
 454                 return;
 455
 456         /* this cpu is going down, migrate to a shared sibling if possible */
 457         for_each_online_cpu(i) {
 458                 struct amd_uncore *that = *per_cpu_ptr(uncores, i);
 459
 460                 if (cpu == i)
 461                         continue;
 462
 463                 if (this == that) {
 464                         perf_pmu_migrate_context(this->pmu, cpu, i);
 465                         cpumask_clear_cpu(cpu, that->active_mask);
 466                         cpumask_set_cpu(i, that->active_mask);
 467                         that->cpu = i;
 468                         break;
 469                 }
 470         }
 471 }
 472
 473 static int amd_uncore_cpu_down_prepare(unsigned int cpu)
 474 {
 475         if (amd_uncore_nb)
 476                 uncore_down_prepare(cpu, amd_uncore_nb);
 477
 478         if (amd_uncore_llc)
 479                 uncore_down_prepare(cpu, amd_uncore_llc);
 480
 481         return 0;
 482 }
 483
 484 static void uncore_dead(unsigned int cpu, struct amd_uncore * __percpu *uncores)
 485 {
 486         struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu);
 487
 488         if (cpu == uncore->cpu)
 489                 cpumask_clear_cpu(cpu, uncore->active_mask);
 490
 491         if (!--uncore->refcnt)
 492                 kfree(uncore);
 493         *per_cpu_ptr(uncores, cpu) = NULL;
 494 }
 495
 496 static int amd_uncore_cpu_dead(unsigned int cpu)
 497 {
 498         if (amd_uncore_nb)
 499                 uncore_dead(cpu, amd_uncore_nb);
 500
 501         if (amd_uncore_llc)
 502                 uncore_dead(cpu, amd_uncore_llc);
 503
 504         return 0;
 505 }
 506
 507 static int __init amd_uncore_init(void)
 508 {
 509         int ret = -ENODEV;
 510
 511         if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
 512                 goto fail_nodev;
 513
 514         switch(boot_cpu_data.x86) {
 515                 case 23:
 516                         /* Family 17h: */
 517                         num_counters_nb = NUM_COUNTERS_NB;
 518                         num_counters_llc = NUM_COUNTERS_L3;
 519                         /*
 520                          * For Family17h, the NorthBridge counters are
 521                          * re-purposed as Data Fabric counters. Also, support is
 522                          * added for L3 counters. The pmus are exported based on
 523                          * family as either L2 or L3 and NB or DF.
 524                          */
 525                         amd_nb_pmu.name = "amd_df";
 526                         amd_llc_pmu.name = "amd_l3";
 527                         format_attr_event_df.show = &event_show_df;
 528                         format_attr_event_l3.show = &event_show_l3;
 529                         break;
 530                 case 22:
 531                         /* Family 16h - may change: */
 532                         num_counters_nb = NUM_COUNTERS_NB;
 533                         num_counters_llc = NUM_COUNTERS_L2;
 534                         amd_nb_pmu.name = "amd_nb";
 535                         amd_llc_pmu.name = "amd_l2";
 536                         format_attr_event_df = format_attr_event;
 537                         format_attr_event_l3 = format_attr_event;
 538                         break;
 539                 default:
 540                         /*
 541                          * All prior families have the same number of
 542                          * NorthBridge and Last Level Cache counters
 543                          */
 544                         num_counters_nb = NUM_COUNTERS_NB;
 545                         num_counters_llc = NUM_COUNTERS_L2;
 546                         amd_nb_pmu.name = "amd_nb";
 547                         amd_llc_pmu.name = "amd_l2";
 548                         format_attr_event_df = format_attr_event;
 549                         format_attr_event_l3 = format_attr_event;
 550                         break;
 551         }
 552         amd_nb_pmu.attr_groups = amd_uncore_attr_groups_df;
 553         amd_llc_pmu.attr_groups = amd_uncore_attr_groups_l3;
 554
 555         if (!boot_cpu_has(X86_FEATURE_TOPOEXT))
 556                 goto fail_nodev;
 557
 558         if (boot_cpu_has(X86_FEATURE_PERFCTR_NB)) {
 559                 amd_uncore_nb = alloc_percpu(struct amd_uncore *);
 560                 if (!amd_uncore_nb) {
 561                         ret = -ENOMEM;
 562                         goto fail_nb;
 563                 }
 564                 ret = perf_pmu_register(&amd_nb_pmu, amd_nb_pmu.name, -1);
 565                 if (ret)
 566                         goto fail_nb;
 567
 568                 pr_info("perf: AMD NB counters detected\n");
 569                 ret = 0;
 570         }
 571
 572         if (boot_cpu_has(X86_FEATURE_PERFCTR_L2)) {
 573                 amd_uncore_llc = alloc_percpu(struct amd_uncore *);
 574                 if (!amd_uncore_llc) {
 575                         ret = -ENOMEM;
 576                         goto fail_llc;
 577                 }
 578                 ret = perf_pmu_register(&amd_llc_pmu, amd_llc_pmu.name, -1);
 579                 if (ret)
 580                         goto fail_llc;
 581
 582                 pr_info("perf: AMD LLC counters detected\n");
 583                 ret = 0;
 584         }
 585
 586         /*
 587          * Install callbacks. Core will call them for each online cpu.
 588          */
 589         if (cpuhp_setup_state(CPUHP_PERF_X86_AMD_UNCORE_PREP,
 590                               "perf/x86/amd/uncore:prepare",
 591                               amd_uncore_cpu_up_prepare, amd_uncore_cpu_dead))
 592                 goto fail_llc;
 593
 594         if (cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
 595                               "perf/x86/amd/uncore:starting",
 596                               amd_uncore_cpu_starting, NULL))
 597                 goto fail_prep;
 598         if (cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
 599                               "perf/x86/amd/uncore:online",
 600                               amd_uncore_cpu_online,
 601                               amd_uncore_cpu_down_prepare))
 602                 goto fail_start;
 603         return 0;
 604
 605 fail_start:
 606         cpuhp_remove_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING);
 607 fail_prep:
 608         cpuhp_remove_state(CPUHP_PERF_X86_AMD_UNCORE_PREP);
 609 fail_llc:
 610         if (boot_cpu_has(X86_FEATURE_PERFCTR_NB))
 611                 perf_pmu_unregister(&amd_nb_pmu);
 612         if (amd_uncore_llc)
 613                 free_percpu(amd_uncore_llc);
 614 fail_nb:
 615         if (amd_uncore_nb)
 616                 free_percpu(amd_uncore_nb);
 617
 618 fail_nodev:
 619         return ret;
 620 }
 621 device_initcall(amd_uncore_init);