arch/arm64/kernel/perf_event.c

   1 /*
   2  * PMU support
   3  *
   4  * Copyright (C) 2012 ARM Limited
   5  * Author: Will Deacon <will.deacon@arm.com>
   6  *
   7  * This code is based heavily on the ARMv7 perf event code.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21 #define pr_fmt(fmt) "hw perfevents: " fmt
  22
  23 #include <linux/bitmap.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/kernel.h>
  26 #include <linux/export.h>
  27 #include <linux/perf_event.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/spinlock.h>
  30 #include <linux/uaccess.h>
  31
  32 #include <asm/cputype.h>
  33 #include <asm/irq.h>
  34 #include <asm/irq_regs.h>
  35 #include <asm/pmu.h>
  36 #include <asm/stacktrace.h>
  37
  38 /*
  39  * ARMv8 supports a maximum of 32 events.
  40  * The cycle counter is included in this total.
  41  */
  42 #define ARMPMU_MAX_HWEVENTS             32
  43
  44 static DEFINE_PER_CPU(struct perf_event * [ARMPMU_MAX_HWEVENTS], hw_events);
  45 static DEFINE_PER_CPU(unsigned long [BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)], used_mask);
  46 static DEFINE_PER_CPU(struct pmu_hw_events, cpu_hw_events);
  47
  48 #define to_arm_pmu(p) (container_of(p, struct arm_pmu, pmu))
  49
  50 /* Set at runtime when we know what CPU type we are. */
  51 static struct arm_pmu *cpu_pmu;
  52
  53 int
  54 armpmu_get_max_events(void)
  55 {
  56         int max_events = 0;
  57
  58         if (cpu_pmu != NULL)
  59                 max_events = cpu_pmu->num_events;
  60
  61         return max_events;
  62 }
  63 EXPORT_SYMBOL_GPL(armpmu_get_max_events);
  64
  65 int perf_num_counters(void)
  66 {
  67         return armpmu_get_max_events();
  68 }
  69 EXPORT_SYMBOL_GPL(perf_num_counters);
  70
  71 #define HW_OP_UNSUPPORTED               0xFFFF
  72
  73 #define C(_x) \
  74         PERF_COUNT_HW_CACHE_##_x
  75
  76 #define CACHE_OP_UNSUPPORTED            0xFFFF
  77
  78 static int
  79 armpmu_map_cache_event(const unsigned (*cache_map)
  80                                       [PERF_COUNT_HW_CACHE_MAX]
  81                                       [PERF_COUNT_HW_CACHE_OP_MAX]
  82                                       [PERF_COUNT_HW_CACHE_RESULT_MAX],
  83                        u64 config)
  84 {
  85         unsigned int cache_type, cache_op, cache_result, ret;
  86
  87         cache_type = (config >>  0) & 0xff;
  88         if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
  89                 return -EINVAL;
  90
  91         cache_op = (config >>  8) & 0xff;
  92         if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
  93                 return -EINVAL;
  94
  95         cache_result = (config >> 16) & 0xff;
  96         if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
  97                 return -EINVAL;
  98
  99         ret = (int)(*cache_map)[cache_type][cache_op][cache_result];
 100
 101         if (ret == CACHE_OP_UNSUPPORTED)
 102                 return -ENOENT;
 103
 104         return ret;
 105 }
 106
 107 static int
 108 armpmu_map_event(const unsigned (*event_map)[PERF_COUNT_HW_MAX], u64 config)
 109 {
 110         int mapping = (*event_map)[config];
 111         return mapping == HW_OP_UNSUPPORTED ? -ENOENT : mapping;
 112 }
 113
 114 static int
 115 armpmu_map_raw_event(u32 raw_event_mask, u64 config)
 116 {
 117         return (int)(config & raw_event_mask);
 118 }
 119
 120 static int map_cpu_event(struct perf_event *event,
 121                          const unsigned (*event_map)[PERF_COUNT_HW_MAX],
 122                          const unsigned (*cache_map)
 123                                         [PERF_COUNT_HW_CACHE_MAX]
 124                                         [PERF_COUNT_HW_CACHE_OP_MAX]
 125                                         [PERF_COUNT_HW_CACHE_RESULT_MAX],
 126                          u32 raw_event_mask)
 127 {
 128         u64 config = event->attr.config;
 129
 130         switch (event->attr.type) {
 131         case PERF_TYPE_HARDWARE:
 132                 return armpmu_map_event(event_map, config);
 133         case PERF_TYPE_HW_CACHE:
 134                 return armpmu_map_cache_event(cache_map, config);
 135         case PERF_TYPE_RAW:
 136                 return armpmu_map_raw_event(raw_event_mask, config);
 137         }
 138
 139         return -ENOENT;
 140 }
 141
 142 int
 143 armpmu_event_set_period(struct perf_event *event,
 144                         struct hw_perf_event *hwc,
 145                         int idx)
 146 {
 147         struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 148         s64 left = local64_read(&hwc->period_left);
 149         s64 period = hwc->sample_period;
 150         int ret = 0;
 151
 152         if (unlikely(left <= -period)) {
 153                 left = period;
 154                 local64_set(&hwc->period_left, left);
 155                 hwc->last_period = period;
 156                 ret = 1;
 157         }
 158
 159         if (unlikely(left <= 0)) {
 160                 left += period;
 161                 local64_set(&hwc->period_left, left);
 162                 hwc->last_period = period;
 163                 ret = 1;
 164         }
 165
 166         if (left > (s64)armpmu->max_period)
 167                 left = armpmu->max_period;
 168
 169         local64_set(&hwc->prev_count, (u64)-left);
 170
 171         armpmu->write_counter(idx, (u64)(-left) & 0xffffffff);
 172
 173         perf_event_update_userpage(event);
 174
 175         return ret;
 176 }
 177
 178 u64
 179 armpmu_event_update(struct perf_event *event,
 180                     struct hw_perf_event *hwc,
 181                     int idx)
 182 {
 183         struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 184         u64 delta, prev_raw_count, new_raw_count;
 185
 186 again:
 187         prev_raw_count = local64_read(&hwc->prev_count);
 188         new_raw_count = armpmu->read_counter(idx);
 189
 190         if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
 191                              new_raw_count) != prev_raw_count)
 192                 goto again;
 193
 194         delta = (new_raw_count - prev_raw_count) & armpmu->max_period;
 195
 196         local64_add(delta, &event->count);
 197         local64_sub(delta, &hwc->period_left);
 198
 199         return new_raw_count;
 200 }
 201
 202 static void
 203 armpmu_read(struct perf_event *event)
 204 {
 205         struct hw_perf_event *hwc = &event->hw;
 206
 207         /* Don't read disabled counters! */
 208         if (hwc->idx < 0)
 209                 return;
 210
 211         armpmu_event_update(event, hwc, hwc->idx);
 212 }
 213
 214 static void
 215 armpmu_stop(struct perf_event *event, int flags)
 216 {
 217         struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 218         struct hw_perf_event *hwc = &event->hw;
 219
 220         /*
 221          * ARM pmu always has to update the counter, so ignore
 222          * PERF_EF_UPDATE, see comments in armpmu_start().
 223          */
 224         if (!(hwc->state & PERF_HES_STOPPED)) {
 225                 armpmu->disable(hwc, hwc->idx);
 226                 barrier(); /* why? */
 227                 armpmu_event_update(event, hwc, hwc->idx);
 228                 hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
 229         }
 230 }
 231
 232 static void
 233 armpmu_start(struct perf_event *event, int flags)
 234 {
 235         struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 236         struct hw_perf_event *hwc = &event->hw;
 237
 238         /*
 239          * ARM pmu always has to reprogram the period, so ignore
 240          * PERF_EF_RELOAD, see the comment below.
 241          */
 242         if (flags & PERF_EF_RELOAD)
 243                 WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
 244
 245         hwc->state = 0;
 246         /*
 247          * Set the period again. Some counters can't be stopped, so when we
 248          * were stopped we simply disabled the IRQ source and the counter
 249          * may have been left counting. If we don't do this step then we may
 250          * get an interrupt too soon or *way* too late if the overflow has
 251          * happened since disabling.
 252          */
 253         armpmu_event_set_period(event, hwc, hwc->idx);
 254         armpmu->enable(hwc, hwc->idx);
 255 }
 256
 257 static void
 258 armpmu_del(struct perf_event *event, int flags)
 259 {
 260         struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 261         struct pmu_hw_events *hw_events = armpmu->get_hw_events();
 262         struct hw_perf_event *hwc = &event->hw;
 263         int idx = hwc->idx;
 264
 265         WARN_ON(idx < 0);
 266
 267         armpmu_stop(event, PERF_EF_UPDATE);
 268         hw_events->events[idx] = NULL;
 269         clear_bit(idx, hw_events->used_mask);
 270
 271         perf_event_update_userpage(event);
 272 }
 273
 274 static int
 275 armpmu_add(struct perf_event *event, int flags)
 276 {
 277         struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 278         struct pmu_hw_events *hw_events = armpmu->get_hw_events();
 279         struct hw_perf_event *hwc = &event->hw;
 280         int idx;
 281         int err = 0;
 282
 283         perf_pmu_disable(event->pmu);
 284
 285         /* If we don't have a space for the counter then finish early. */
 286         idx = armpmu->get_event_idx(hw_events, hwc);
 287         if (idx < 0) {
 288                 err = idx;
 289                 goto out;
 290         }
 291
 292         /*
 293          * If there is an event in the counter we are going to use then make
 294          * sure it is disabled.
 295          */
 296         event->hw.idx = idx;
 297         armpmu->disable(hwc, idx);
 298         hw_events->events[idx] = event;
 299
 300         hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
 301         if (flags & PERF_EF_START)
 302                 armpmu_start(event, PERF_EF_RELOAD);
 303
 304         /* Propagate our changes to the userspace mapping. */
 305         perf_event_update_userpage(event);
 306
 307 out:
 308         perf_pmu_enable(event->pmu);
 309         return err;
 310 }
 311
 312 static int
 313 validate_event(struct pmu_hw_events *hw_events,
 314                struct perf_event *event)
 315 {
 316         struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 317         struct hw_perf_event fake_event = event->hw;
 318         struct pmu *leader_pmu = event->group_leader->pmu;
 319
 320         if (event->pmu != leader_pmu || event->state <= PERF_EVENT_STATE_OFF)
 321                 return 1;
 322
 323         return armpmu->get_event_idx(hw_events, &fake_event) >= 0;
 324 }
 325
 326 static int
 327 validate_group(struct perf_event *event)
 328 {
 329         struct perf_event *sibling, *leader = event->group_leader;
 330         struct pmu_hw_events fake_pmu;
 331         DECLARE_BITMAP(fake_used_mask, ARMPMU_MAX_HWEVENTS);
 332
 333         /*
 334          * Initialise the fake PMU. We only need to populate the
 335          * used_mask for the purposes of validation.
 336          */
 337         memset(fake_used_mask, 0, sizeof(fake_used_mask));
 338         fake_pmu.used_mask = fake_used_mask;
 339
 340         if (!validate_event(&fake_pmu, leader))
 341                 return -EINVAL;
 342
 343         list_for_each_entry(sibling, &leader->sibling_list, group_entry) {
 344                 if (!validate_event(&fake_pmu, sibling))
 345                         return -EINVAL;
 346         }
 347
 348         if (!validate_event(&fake_pmu, event))
 349                 return -EINVAL;
 350
 351         return 0;
 352 }
 353
 354 static void
 355 armpmu_release_hardware(struct arm_pmu *armpmu)
 356 {
 357         int i, irq, irqs;
 358         struct platform_device *pmu_device = armpmu->plat_device;
 359
 360         irqs = min(pmu_device->num_resources, num_possible_cpus());
 361
 362         for (i = 0; i < irqs; ++i) {
 363                 if (!cpumask_test_and_clear_cpu(i, &armpmu->active_irqs))
 364                         continue;
 365                 irq = platform_get_irq(pmu_device, i);
 366                 if (irq >= 0)
 367                         free_irq(irq, armpmu);
 368         }
 369 }
 370
 371 static int
 372 armpmu_reserve_hardware(struct arm_pmu *armpmu)
 373 {
 374         int i, err, irq, irqs;
 375         struct platform_device *pmu_device = armpmu->plat_device;
 376
 377         if (!pmu_device) {
 378                 pr_err("no PMU device registered\n");
 379                 return -ENODEV;
 380         }
 381
 382         irqs = min(pmu_device->num_resources, num_possible_cpus());
 383         if (irqs < 1) {
 384                 pr_err("no irqs for PMUs defined\n");
 385                 return -ENODEV;
 386         }
 387
 388         for (i = 0; i < irqs; ++i) {
 389                 err = 0;
 390                 irq = platform_get_irq(pmu_device, i);
 391                 if (irq < 0)
 392                         continue;
 393
 394                 /*
 395                  * If we have a single PMU interrupt that we can't shift,
 396                  * assume that we're running on a uniprocessor machine and
 397                  * continue. Otherwise, continue without this interrupt.
 398                  */
 399                 if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) {
 400                         pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n",
 401                                     irq, i);
 402                         continue;
 403                 }
 404
 405                 err = request_irq(irq, armpmu->handle_irq,
 406                                   IRQF_NOBALANCING,
 407                                   "arm-pmu", armpmu);
 408                 if (err) {
 409                         pr_err("unable to request IRQ%d for ARM PMU counters\n",
 410                                 irq);
 411                         armpmu_release_hardware(armpmu);
 412                         return err;
 413                 }
 414
 415                 cpumask_set_cpu(i, &armpmu->active_irqs);
 416         }
 417
 418         return 0;
 419 }
 420
 421 static void
 422 hw_perf_event_destroy(struct perf_event *event)
 423 {
 424         struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 425         atomic_t *active_events  = &armpmu->active_events;
 426         struct mutex *pmu_reserve_mutex = &armpmu->reserve_mutex;
 427
 428         if (atomic_dec_and_mutex_lock(active_events, pmu_reserve_mutex)) {
 429                 armpmu_release_hardware(armpmu);
 430                 mutex_unlock(pmu_reserve_mutex);
 431         }
 432 }
 433
 434 static int
 435 event_requires_mode_exclusion(struct perf_event_attr *attr)
 436 {
 437         return attr->exclude_idle || attr->exclude_user ||
 438                attr->exclude_kernel || attr->exclude_hv;
 439 }
 440
 441 static int
 442 __hw_perf_event_init(struct perf_event *event)
 443 {
 444         struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 445         struct hw_perf_event *hwc = &event->hw;
 446         int mapping, err;
 447
 448         mapping = armpmu->map_event(event);
 449
 450         if (mapping < 0) {
 451                 pr_debug("event %x:%llx not supported\n", event->attr.type,
 452                          event->attr.config);
 453                 return mapping;
 454         }
 455
 456         /*
 457          * We don't assign an index until we actually place the event onto
 458          * hardware. Use -1 to signify that we haven't decided where to put it
 459          * yet. For SMP systems, each core has it's own PMU so we can't do any
 460          * clever allocation or constraints checking at this point.
 461          */
 462         hwc->idx                = -1;
 463         hwc->config_base        = 0;
 464         hwc->config             = 0;
 465         hwc->event_base         = 0;
 466
 467         /*
 468          * Check whether we need to exclude the counter from certain modes.
 469          */
 470         if ((!armpmu->set_event_filter ||
 471              armpmu->set_event_filter(hwc, &event->attr)) &&
 472              event_requires_mode_exclusion(&event->attr)) {
 473                 pr_debug("ARM performance counters do not support mode exclusion\n");
 474                 return -EPERM;
 475         }
 476
 477         /*
 478          * Store the event encoding into the config_base field.
 479          */
 480         hwc->config_base            |= (unsigned long)mapping;
 481
 482         if (!hwc->sample_period) {
 483                 /*
 484                  * For non-sampling runs, limit the sample_period to half
 485                  * of the counter width. That way, the new counter value
 486                  * is far less likely to overtake the previous one unless
 487                  * you have some serious IRQ latency issues.
 488                  */
 489                 hwc->sample_period  = armpmu->max_period >> 1;
 490                 hwc->last_period    = hwc->sample_period;
 491                 local64_set(&hwc->period_left, hwc->sample_period);
 492         }
 493
 494         err = 0;
 495         if (event->group_leader != event) {
 496                 err = validate_group(event);
 497                 if (err)
 498                         return -EINVAL;
 499         }
 500
 501         return err;
 502 }
 503
 504 static int armpmu_event_init(struct perf_event *event)
 505 {
 506         struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 507         int err = 0;
 508         atomic_t *active_events = &armpmu->active_events;
 509
 510         if (armpmu->map_event(event) == -ENOENT)
 511                 return -ENOENT;
 512
 513         event->destroy = hw_perf_event_destroy;
 514
 515         if (!atomic_inc_not_zero(active_events)) {
 516                 mutex_lock(&armpmu->reserve_mutex);
 517                 if (atomic_read(active_events) == 0)
 518                         err = armpmu_reserve_hardware(armpmu);
 519
 520                 if (!err)
 521                         atomic_inc(active_events);
 522                 mutex_unlock(&armpmu->reserve_mutex);
 523         }
 524
 525         if (err)
 526                 return err;
 527
 528         err = __hw_perf_event_init(event);
 529         if (err)
 530                 hw_perf_event_destroy(event);
 531
 532         return err;
 533 }
 534
 535 static void armpmu_enable(struct pmu *pmu)
 536 {
 537         struct arm_pmu *armpmu = to_arm_pmu(pmu);
 538         struct pmu_hw_events *hw_events = armpmu->get_hw_events();
 539         int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events);
 540
 541         if (enabled)
 542                 armpmu->start();
 543 }
 544
 545 static void armpmu_disable(struct pmu *pmu)
 546 {
 547         struct arm_pmu *armpmu = to_arm_pmu(pmu);
 548         armpmu->stop();
 549 }
 550
 551 static void __init armpmu_init(struct arm_pmu *armpmu)
 552 {
 553         atomic_set(&armpmu->active_events, 0);
 554         mutex_init(&armpmu->reserve_mutex);
 555
 556         armpmu->pmu = (struct pmu) {
 557                 .pmu_enable     = armpmu_enable,
 558                 .pmu_disable    = armpmu_disable,
 559                 .event_init     = armpmu_event_init,
 560                 .add            = armpmu_add,
 561                 .del            = armpmu_del,
 562                 .start          = armpmu_start,
 563                 .stop           = armpmu_stop,
 564                 .read           = armpmu_read,
 565         };
 566 }
 567
 568 int __init armpmu_register(struct arm_pmu *armpmu, char *name, int type)
 569 {
 570         armpmu_init(armpmu);
 571         return perf_pmu_register(&armpmu->pmu, name, type);
 572 }
 573
 574 /*
 575  * ARMv8 PMUv3 Performance Events handling code.
 576  * Common event types.
 577  */
 578 enum armv8_pmuv3_perf_types {
 579         /* Required events. */
 580         ARMV8_PMUV3_PERFCTR_PMNC_SW_INCR                        = 0x00,
 581         ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL                    = 0x03,
 582         ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS                    = 0x04,
 583         ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED                  = 0x10,
 584         ARMV8_PMUV3_PERFCTR_CLOCK_CYCLES                        = 0x11,
 585         ARMV8_PMUV3_PERFCTR_PC_BRANCH_PRED                      = 0x12,
 586
 587         /* At least one of the following is required. */
 588         ARMV8_PMUV3_PERFCTR_INSTR_EXECUTED                      = 0x08,
 589         ARMV8_PMUV3_PERFCTR_OP_SPEC                             = 0x1B,
 590
 591         /* Common architectural events. */
 592         ARMV8_PMUV3_PERFCTR_MEM_READ                            = 0x06,
 593         ARMV8_PMUV3_PERFCTR_MEM_WRITE                           = 0x07,
 594         ARMV8_PMUV3_PERFCTR_EXC_TAKEN                           = 0x09,
 595         ARMV8_PMUV3_PERFCTR_EXC_EXECUTED                        = 0x0A,
 596         ARMV8_PMUV3_PERFCTR_CID_WRITE                           = 0x0B,
 597         ARMV8_PMUV3_PERFCTR_PC_WRITE                            = 0x0C,
 598         ARMV8_PMUV3_PERFCTR_PC_IMM_BRANCH                       = 0x0D,
 599         ARMV8_PMUV3_PERFCTR_PC_PROC_RETURN                      = 0x0E,
 600         ARMV8_PMUV3_PERFCTR_MEM_UNALIGNED_ACCESS                = 0x0F,
 601         ARMV8_PMUV3_PERFCTR_TTBR_WRITE                          = 0x1C,
 602
 603         /* Common microarchitectural events. */
 604         ARMV8_PMUV3_PERFCTR_L1_ICACHE_REFILL                    = 0x01,
 605         ARMV8_PMUV3_PERFCTR_ITLB_REFILL                         = 0x02,
 606         ARMV8_PMUV3_PERFCTR_DTLB_REFILL                         = 0x05,
 607         ARMV8_PMUV3_PERFCTR_MEM_ACCESS                          = 0x13,
 608         ARMV8_PMUV3_PERFCTR_L1_ICACHE_ACCESS                    = 0x14,
 609         ARMV8_PMUV3_PERFCTR_L1_DCACHE_WB                        = 0x15,
 610         ARMV8_PMUV3_PERFCTR_L2_CACHE_ACCESS                     = 0x16,
 611         ARMV8_PMUV3_PERFCTR_L2_CACHE_REFILL                     = 0x17,
 612         ARMV8_PMUV3_PERFCTR_L2_CACHE_WB                         = 0x18,
 613         ARMV8_PMUV3_PERFCTR_BUS_ACCESS                          = 0x19,
 614         ARMV8_PMUV3_PERFCTR_MEM_ERROR                           = 0x1A,
 615         ARMV8_PMUV3_PERFCTR_BUS_CYCLES                          = 0x1D,
 616 };
 617
 618 /* PMUv3 HW events mapping. */
 619 static const unsigned armv8_pmuv3_perf_map[PERF_COUNT_HW_MAX] = {
 620         [PERF_COUNT_HW_CPU_CYCLES]              = ARMV8_PMUV3_PERFCTR_CLOCK_CYCLES,
 621         [PERF_COUNT_HW_INSTRUCTIONS]            = ARMV8_PMUV3_PERFCTR_INSTR_EXECUTED,
 622         [PERF_COUNT_HW_CACHE_REFERENCES]        = ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS,
 623         [PERF_COUNT_HW_CACHE_MISSES]            = ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL,
 624         [PERF_COUNT_HW_BRANCH_INSTRUCTIONS]     = HW_OP_UNSUPPORTED,
 625         [PERF_COUNT_HW_BRANCH_MISSES]           = ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED,
 626         [PERF_COUNT_HW_BUS_CYCLES]              = HW_OP_UNSUPPORTED,
 627         [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = HW_OP_UNSUPPORTED,
 628         [PERF_COUNT_HW_STALLED_CYCLES_BACKEND]  = HW_OP_UNSUPPORTED,
 629 };
 630
 631 static const unsigned armv8_pmuv3_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
 632                                                 [PERF_COUNT_HW_CACHE_OP_MAX]
 633                                                 [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
 634         [C(L1D)] = {
 635                 [C(OP_READ)] = {
 636                         [C(RESULT_ACCESS)]      = ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS,
 637                         [C(RESULT_MISS)]        = ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL,
 638                 },
 639                 [C(OP_WRITE)] = {
 640                         [C(RESULT_ACCESS)]      = ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS,
 641                         [C(RESULT_MISS)]        = ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL,
 642                 },
 643                 [C(OP_PREFETCH)] = {
 644                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 645                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 646                 },
 647         },
 648         [C(L1I)] = {
 649                 [C(OP_READ)] = {
 650                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 651                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 652                 },
 653                 [C(OP_WRITE)] = {
 654                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 655                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 656                 },
 657                 [C(OP_PREFETCH)] = {
 658                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 659                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 660                 },
 661         },
 662         [C(LL)] = {
 663                 [C(OP_READ)] = {
 664                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 665                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 666                 },
 667                 [C(OP_WRITE)] = {
 668                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 669                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 670                 },
 671                 [C(OP_PREFETCH)] = {
 672                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 673                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 674                 },
 675         },
 676         [C(DTLB)] = {
 677                 [C(OP_READ)] = {
 678                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 679                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 680                 },
 681                 [C(OP_WRITE)] = {
 682                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 683                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 684                 },
 685                 [C(OP_PREFETCH)] = {
 686                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 687                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 688                 },
 689         },
 690         [C(ITLB)] = {
 691                 [C(OP_READ)] = {
 692                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 693                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 694                 },
 695                 [C(OP_WRITE)] = {
 696                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 697                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 698                 },
 699                 [C(OP_PREFETCH)] = {
 700                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 701                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 702                 },
 703         },
 704         [C(BPU)] = {
 705                 [C(OP_READ)] = {
 706                         [C(RESULT_ACCESS)]      = ARMV8_PMUV3_PERFCTR_PC_BRANCH_PRED,
 707                         [C(RESULT_MISS)]        = ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED,
 708                 },
 709                 [C(OP_WRITE)] = {
 710                         [C(RESULT_ACCESS)]      = ARMV8_PMUV3_PERFCTR_PC_BRANCH_PRED,
 711                         [C(RESULT_MISS)]        = ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED,
 712                 },
 713                 [C(OP_PREFETCH)] = {
 714                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 715                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 716                 },
 717         },
 718         [C(NODE)] = {
 719                 [C(OP_READ)] = {
 720                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 721                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 722                 },
 723                 [C(OP_WRITE)] = {
 724                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 725                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 726                 },
 727                 [C(OP_PREFETCH)] = {
 728                         [C(RESULT_ACCESS)]      = CACHE_OP_UNSUPPORTED,
 729                         [C(RESULT_MISS)]        = CACHE_OP_UNSUPPORTED,
 730                 },
 731         },
 732 };
 733
 734 /*
 735  * Perf Events' indices
 736  */
 737 #define ARMV8_IDX_CYCLE_COUNTER 0
 738 #define ARMV8_IDX_COUNTER0      1
 739 #define ARMV8_IDX_COUNTER_LAST  (ARMV8_IDX_CYCLE_COUNTER + cpu_pmu->num_events - 1)
 740
 741 #define ARMV8_MAX_COUNTERS      32
 742 #define ARMV8_COUNTER_MASK      (ARMV8_MAX_COUNTERS - 1)
 743
 744 /*
 745  * ARMv8 low level PMU access
 746  */
 747
 748 /*
 749  * Perf Event to low level counters mapping
 750  */
 751 #define ARMV8_IDX_TO_COUNTER(x) \
 752         (((x) - ARMV8_IDX_COUNTER0) & ARMV8_COUNTER_MASK)
 753
 754 /*
 755  * Per-CPU PMCR: config reg
 756  */
 757 #define ARMV8_PMCR_E            (1 << 0) /* Enable all counters */
 758 #define ARMV8_PMCR_P            (1 << 1) /* Reset all counters */
 759 #define ARMV8_PMCR_C            (1 << 2) /* Cycle counter reset */
 760 #define ARMV8_PMCR_D            (1 << 3) /* CCNT counts every 64th cpu cycle */
 761 #define ARMV8_PMCR_X            (1 << 4) /* Export to ETM */
 762 #define ARMV8_PMCR_DP           (1 << 5) /* Disable CCNT if non-invasive debug*/
 763 #define ARMV8_PMCR_N_SHIFT      11       /* Number of counters supported */
 764 #define ARMV8_PMCR_N_MASK       0x1f
 765 #define ARMV8_PMCR_MASK         0x3f     /* Mask for writable bits */
 766
 767 /*
 768  * PMOVSR: counters overflow flag status reg
 769  */
 770 #define ARMV8_OVSR_MASK         0xffffffff      /* Mask for writable bits */
 771 #define ARMV8_OVERFLOWED_MASK   ARMV8_OVSR_MASK
 772
 773 /*
 774  * PMXEVTYPER: Event selection reg
 775  */
 776 #define ARMV8_EVTYPE_MASK       0xc00000ff      /* Mask for writable bits */
 777 #define ARMV8_EVTYPE_EVENT      0xff            /* Mask for EVENT bits */
 778
 779 /*
 780  * Event filters for PMUv3
 781  */
 782 #define ARMV8_EXCLUDE_EL1       (1 << 31)
 783 #define ARMV8_EXCLUDE_EL0       (1 << 30)
 784 #define ARMV8_INCLUDE_EL2       (1 << 27)
 785
 786 static inline u32 armv8pmu_pmcr_read(void)
 787 {
 788         u32 val;
 789         asm volatile("mrs %0, pmcr_el0" : "=r" (val));
 790         return val;
 791 }
 792
 793 static inline void armv8pmu_pmcr_write(u32 val)
 794 {
 795         val &= ARMV8_PMCR_MASK;
 796         isb();
 797         asm volatile("msr pmcr_el0, %0" :: "r" (val));
 798 }
 799
 800 static inline int armv8pmu_has_overflowed(u32 pmovsr)
 801 {
 802         return pmovsr & ARMV8_OVERFLOWED_MASK;
 803 }
 804
 805 static inline int armv8pmu_counter_valid(int idx)
 806 {
 807         return idx >= ARMV8_IDX_CYCLE_COUNTER && idx <= ARMV8_IDX_COUNTER_LAST;
 808 }
 809
 810 static inline int armv8pmu_counter_has_overflowed(u32 pmnc, int idx)
 811 {
 812         int ret = 0;
 813         u32 counter;
 814
 815         if (!armv8pmu_counter_valid(idx)) {
 816                 pr_err("CPU%u checking wrong counter %d overflow status\n",
 817                         smp_processor_id(), idx);
 818         } else {
 819                 counter = ARMV8_IDX_TO_COUNTER(idx);
 820                 ret = pmnc & BIT(counter);
 821         }
 822
 823         return ret;
 824 }
 825
 826 static inline int armv8pmu_select_counter(int idx)
 827 {
 828         u32 counter;
 829
 830         if (!armv8pmu_counter_valid(idx)) {
 831                 pr_err("CPU%u selecting wrong PMNC counter %d\n",
 832                         smp_processor_id(), idx);
 833                 return -EINVAL;
 834         }
 835
 836         counter = ARMV8_IDX_TO_COUNTER(idx);
 837         asm volatile("msr pmselr_el0, %0" :: "r" (counter));
 838         isb();
 839
 840         return idx;
 841 }
 842
 843 static inline u32 armv8pmu_read_counter(int idx)
 844 {
 845         u32 value = 0;
 846
 847         if (!armv8pmu_counter_valid(idx))
 848                 pr_err("CPU%u reading wrong counter %d\n",
 849                         smp_processor_id(), idx);
 850         else if (idx == ARMV8_IDX_CYCLE_COUNTER)
 851                 asm volatile("mrs %0, pmccntr_el0" : "=r" (value));
 852         else if (armv8pmu_select_counter(idx) == idx)
 853                 asm volatile("mrs %0, pmxevcntr_el0" : "=r" (value));
 854
 855         return value;
 856 }
 857
 858 static inline void armv8pmu_write_counter(int idx, u32 value)
 859 {
 860         if (!armv8pmu_counter_valid(idx))
 861                 pr_err("CPU%u writing wrong counter %d\n",
 862                         smp_processor_id(), idx);
 863         else if (idx == ARMV8_IDX_CYCLE_COUNTER)
 864                 asm volatile("msr pmccntr_el0, %0" :: "r" (value));
 865         else if (armv8pmu_select_counter(idx) == idx)
 866                 asm volatile("msr pmxevcntr_el0, %0" :: "r" (value));
 867 }
 868
 869 static inline void armv8pmu_write_evtype(int idx, u32 val)
 870 {
 871         if (armv8pmu_select_counter(idx) == idx) {
 872                 val &= ARMV8_EVTYPE_MASK;
 873                 asm volatile("msr pmxevtyper_el0, %0" :: "r" (val));
 874         }
 875 }
 876
 877 static inline int armv8pmu_enable_counter(int idx)
 878 {
 879         u32 counter;
 880
 881         if (!armv8pmu_counter_valid(idx)) {
 882                 pr_err("CPU%u enabling wrong PMNC counter %d\n",
 883                         smp_processor_id(), idx);
 884                 return -EINVAL;
 885         }
 886
 887         counter = ARMV8_IDX_TO_COUNTER(idx);
 888         asm volatile("msr pmcntenset_el0, %0" :: "r" (BIT(counter)));
 889         return idx;
 890 }
 891
 892 static inline int armv8pmu_disable_counter(int idx)
 893 {
 894         u32 counter;
 895
 896         if (!armv8pmu_counter_valid(idx)) {
 897                 pr_err("CPU%u disabling wrong PMNC counter %d\n",
 898                         smp_processor_id(), idx);
 899                 return -EINVAL;
 900         }
 901
 902         counter = ARMV8_IDX_TO_COUNTER(idx);
 903         asm volatile("msr pmcntenclr_el0, %0" :: "r" (BIT(counter)));
 904         return idx;
 905 }
 906
 907 static inline int armv8pmu_enable_intens(int idx)
 908 {
 909         u32 counter;
 910
 911         if (!armv8pmu_counter_valid(idx)) {
 912                 pr_err("CPU%u enabling wrong PMNC counter IRQ enable %d\n",
 913                         smp_processor_id(), idx);
 914                 return -EINVAL;
 915         }
 916
 917         counter = ARMV8_IDX_TO_COUNTER(idx);
 918         asm volatile("msr pmintenset_el1, %0" :: "r" (BIT(counter)));
 919         return idx;
 920 }
 921
 922 static inline int armv8pmu_disable_intens(int idx)
 923 {
 924         u32 counter;
 925
 926         if (!armv8pmu_counter_valid(idx)) {
 927                 pr_err("CPU%u disabling wrong PMNC counter IRQ enable %d\n",
 928                         smp_processor_id(), idx);
 929                 return -EINVAL;
 930         }
 931
 932         counter = ARMV8_IDX_TO_COUNTER(idx);
 933         asm volatile("msr pmintenclr_el1, %0" :: "r" (BIT(counter)));
 934         isb();
 935         /* Clear the overflow flag in case an interrupt is pending. */
 936         asm volatile("msr pmovsclr_el0, %0" :: "r" (BIT(counter)));
 937         isb();
 938         return idx;
 939 }
 940
 941 static inline u32 armv8pmu_getreset_flags(void)
 942 {
 943         u32 value;
 944
 945         /* Read */
 946         asm volatile("mrs %0, pmovsclr_el0" : "=r" (value));
 947
 948         /* Write to clear flags */
 949         value &= ARMV8_OVSR_MASK;
 950         asm volatile("msr pmovsclr_el0, %0" :: "r" (value));
 951
 952         return value;
 953 }
 954
 955 static void armv8pmu_enable_event(struct hw_perf_event *hwc, int idx)
 956 {
 957         unsigned long flags;
 958         struct pmu_hw_events *events = cpu_pmu->get_hw_events();
 959
 960         /*
 961          * Enable counter and interrupt, and set the counter to count
 962          * the event that we're interested in.
 963          */
 964         raw_spin_lock_irqsave(&events->pmu_lock, flags);
 965
 966         /*
 967          * Disable counter
 968          */
 969         armv8pmu_disable_counter(idx);
 970
 971         /*
 972          * Set event (if destined for PMNx counters).
 973          */
 974         armv8pmu_write_evtype(idx, hwc->config_base);
 975
 976         /*
 977          * Enable interrupt for this counter
 978          */
 979         armv8pmu_enable_intens(idx);
 980
 981         /*
 982          * Enable counter
 983          */
 984         armv8pmu_enable_counter(idx);
 985
 986         raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
 987 }
 988
 989 static void armv8pmu_disable_event(struct hw_perf_event *hwc, int idx)
 990 {
 991         unsigned long flags;
 992         struct pmu_hw_events *events = cpu_pmu->get_hw_events();
 993
 994         /*
 995          * Disable counter and interrupt
 996          */
 997         raw_spin_lock_irqsave(&events->pmu_lock, flags);
 998
 999         /*
1000          * Disable counter
1001          */
1002         armv8pmu_disable_counter(idx);
1003
1004         /*
1005          * Disable interrupt for this counter
1006          */
1007         armv8pmu_disable_intens(idx);
1008
1009         raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
1010 }
1011
1012 static irqreturn_t armv8pmu_handle_irq(int irq_num, void *dev)
1013 {
1014         u32 pmovsr;
1015         struct perf_sample_data data;
1016         struct pmu_hw_events *cpuc;
1017         struct pt_regs *regs;
1018         int idx;
1019
1020         /*
1021          * Get and reset the IRQ flags
1022          */
1023         pmovsr = armv8pmu_getreset_flags();
1024
1025         /*
1026          * Did an overflow occur?
1027          */
1028         if (!armv8pmu_has_overflowed(pmovsr))
1029                 return IRQ_NONE;
1030
1031         /*
1032          * Handle the counter(s) overflow(s)
1033          */
1034         regs = get_irq_regs();
1035
1036         cpuc = &__get_cpu_var(cpu_hw_events);
1037         for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
1038                 struct perf_event *event = cpuc->events[idx];
1039                 struct hw_perf_event *hwc;
1040
1041                 /* Ignore if we don't have an event. */
1042                 if (!event)
1043                         continue;
1044
1045                 /*
1046                  * We have a single interrupt for all counters. Check that
1047                  * each counter has overflowed before we process it.
1048                  */
1049                 if (!armv8pmu_counter_has_overflowed(pmovsr, idx))
1050                         continue;
1051
1052                 hwc = &event->hw;
1053                 armpmu_event_update(event, hwc, idx);
1054                 perf_sample_data_init(&data, 0, hwc->last_period);
1055                 if (!armpmu_event_set_period(event, hwc, idx))
1056                         continue;
1057
1058                 if (perf_event_overflow(event, &data, regs))
1059                         cpu_pmu->disable(hwc, idx);
1060         }
1061
1062         /*
1063          * Handle the pending perf events.
1064          *
1065          * Note: this call *must* be run with interrupts disabled. For
1066          * platforms that can have the PMU interrupts raised as an NMI, this
1067          * will not work.
1068          */
1069         irq_work_run();
1070
1071         return IRQ_HANDLED;
1072 }
1073
1074 static void armv8pmu_start(void)
1075 {
1076         unsigned long flags;
1077         struct pmu_hw_events *events = cpu_pmu->get_hw_events();
1078
1079         raw_spin_lock_irqsave(&events->pmu_lock, flags);
1080         /* Enable all counters */
1081         armv8pmu_pmcr_write(armv8pmu_pmcr_read() | ARMV8_PMCR_E);
1082         raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
1083 }
1084
1085 static void armv8pmu_stop(void)
1086 {
1087         unsigned long flags;
1088         struct pmu_hw_events *events = cpu_pmu->get_hw_events();
1089
1090         raw_spin_lock_irqsave(&events->pmu_lock, flags);
1091         /* Disable all counters */
1092         armv8pmu_pmcr_write(armv8pmu_pmcr_read() & ~ARMV8_PMCR_E);
1093         raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
1094 }
1095
1096 static int armv8pmu_get_event_idx(struct pmu_hw_events *cpuc,
1097                                   struct hw_perf_event *event)
1098 {
1099         int idx;
1100         unsigned long evtype = event->config_base & ARMV8_EVTYPE_EVENT;
1101
1102         /* Always place a cycle counter into the cycle counter. */
1103         if (evtype == ARMV8_PMUV3_PERFCTR_CLOCK_CYCLES) {
1104                 if (test_and_set_bit(ARMV8_IDX_CYCLE_COUNTER, cpuc->used_mask))
1105                         return -EAGAIN;
1106
1107                 return ARMV8_IDX_CYCLE_COUNTER;
1108         }
1109
1110         /*
1111          * For anything other than a cycle counter, try and use
1112          * the events counters
1113          */
1114         for (idx = ARMV8_IDX_COUNTER0; idx < cpu_pmu->num_events; ++idx) {
1115                 if (!test_and_set_bit(idx, cpuc->used_mask))
1116                         return idx;
1117         }
1118
1119         /* The counters are all in use. */
1120         return -EAGAIN;
1121 }
1122
1123 /*
1124  * Add an event filter to a given event. This will only work for PMUv2 PMUs.
1125  */
1126 static int armv8pmu_set_event_filter(struct hw_perf_event *event,
1127                                      struct perf_event_attr *attr)
1128 {
1129         unsigned long config_base = 0;
1130
1131         if (attr->exclude_idle)
1132                 return -EPERM;
1133         if (attr->exclude_user)
1134                 config_base |= ARMV8_EXCLUDE_EL0;
1135         if (attr->exclude_kernel)
1136                 config_base |= ARMV8_EXCLUDE_EL1;
1137         if (!attr->exclude_hv)
1138                 config_base |= ARMV8_INCLUDE_EL2;
1139
1140         /*
1141          * Install the filter into config_base as this is used to
1142          * construct the event type.
1143          */
1144         event->config_base = config_base;
1145
1146         return 0;
1147 }
1148
1149 static void armv8pmu_reset(void *info)
1150 {
1151         u32 idx, nb_cnt = cpu_pmu->num_events;
1152
1153         /* The counter and interrupt enable registers are unknown at reset. */
1154         for (idx = ARMV8_IDX_CYCLE_COUNTER; idx < nb_cnt; ++idx)
1155                 armv8pmu_disable_event(NULL, idx);
1156
1157         /* Initialize & Reset PMNC: C and P bits. */
1158         armv8pmu_pmcr_write(ARMV8_PMCR_P | ARMV8_PMCR_C);
1159
1160         /* Disable access from userspace. */
1161         asm volatile("msr pmuserenr_el0, %0" :: "r" (0));
1162 }
1163
1164 static int armv8_pmuv3_map_event(struct perf_event *event)
1165 {
1166         return map_cpu_event(event, &armv8_pmuv3_perf_map,
1167                                 &armv8_pmuv3_perf_cache_map, 0xFF);
1168 }
1169
1170 static struct arm_pmu armv8pmu = {
1171         .handle_irq             = armv8pmu_handle_irq,
1172         .enable                 = armv8pmu_enable_event,
1173         .disable                = armv8pmu_disable_event,
1174         .read_counter           = armv8pmu_read_counter,
1175         .write_counter          = armv8pmu_write_counter,
1176         .get_event_idx          = armv8pmu_get_event_idx,
1177         .start                  = armv8pmu_start,
1178         .stop                   = armv8pmu_stop,
1179         .reset                  = armv8pmu_reset,
1180         .max_period             = (1LLU << 32) - 1,
1181 };
1182
1183 static u32 __init armv8pmu_read_num_pmnc_events(void)
1184 {
1185         u32 nb_cnt;
1186
1187         /* Read the nb of CNTx counters supported from PMNC */
1188         nb_cnt = (armv8pmu_pmcr_read() >> ARMV8_PMCR_N_SHIFT) & ARMV8_PMCR_N_MASK;
1189
1190         /* Add the CPU cycles counter and return */
1191         return nb_cnt + 1;
1192 }
1193
1194 static struct arm_pmu *__init armv8_pmuv3_pmu_init(void)
1195 {
1196         armv8pmu.name                   = "arm/armv8-pmuv3";
1197         armv8pmu.map_event              = armv8_pmuv3_map_event;
1198         armv8pmu.num_events             = armv8pmu_read_num_pmnc_events();
1199         armv8pmu.set_event_filter       = armv8pmu_set_event_filter;
1200         return &armv8pmu;
1201 }
1202
1203 /*
1204  * Ensure the PMU has sane values out of reset.
1205  * This requires SMP to be available, so exists as a separate initcall.
1206  */
1207 static int __init
1208 cpu_pmu_reset(void)
1209 {
1210         if (cpu_pmu && cpu_pmu->reset)
1211                 return on_each_cpu(cpu_pmu->reset, NULL, 1);
1212         return 0;
1213 }
1214 arch_initcall(cpu_pmu_reset);
1215
1216 /*
1217  * PMU platform driver and devicetree bindings.
1218  */
1219 static struct of_device_id armpmu_of_device_ids[] = {
1220         {.compatible = "arm,armv8-pmuv3"},
1221         {},
1222 };
1223
1224 static int armpmu_device_probe(struct platform_device *pdev)
1225 {
1226         if (!cpu_pmu)
1227                 return -ENODEV;
1228
1229         cpu_pmu->plat_device = pdev;
1230         return 0;
1231 }
1232
1233 static struct platform_driver armpmu_driver = {
1234         .driver         = {
1235                 .name   = "arm-pmu",
1236                 .of_match_table = armpmu_of_device_ids,
1237         },
1238         .probe          = armpmu_device_probe,
1239 };
1240
1241 static int __init register_pmu_driver(void)
1242 {
1243         return platform_driver_register(&armpmu_driver);
1244 }
1245 device_initcall(register_pmu_driver);
1246
1247 static struct pmu_hw_events *armpmu_get_cpu_events(void)
1248 {
1249         return &__get_cpu_var(cpu_hw_events);
1250 }
1251
1252 static void __init cpu_pmu_init(struct arm_pmu *armpmu)
1253 {
1254         int cpu;
1255         for_each_possible_cpu(cpu) {
1256                 struct pmu_hw_events *events = &per_cpu(cpu_hw_events, cpu);
1257                 events->events = per_cpu(hw_events, cpu);
1258                 events->used_mask = per_cpu(used_mask, cpu);
1259                 raw_spin_lock_init(&events->pmu_lock);
1260         }
1261         armpmu->get_hw_events = armpmu_get_cpu_events;
1262 }
1263
1264 static int __init init_hw_perf_events(void)
1265 {
1266         u64 dfr = read_cpuid(ID_AA64DFR0_EL1);
1267
1268         switch ((dfr >> 8) & 0xf) {
1269         case 0x1:       /* PMUv3 */
1270                 cpu_pmu = armv8_pmuv3_pmu_init();
1271                 break;
1272         }
1273
1274         if (cpu_pmu) {
1275                 pr_info("enabled with %s PMU driver, %d counters available\n",
1276                         cpu_pmu->name, cpu_pmu->num_events);
1277                 cpu_pmu_init(cpu_pmu);
1278                 armpmu_register(cpu_pmu, "cpu", PERF_TYPE_RAW);
1279         } else {
1280                 pr_info("no hardware support available\n");
1281         }
1282
1283         return 0;
1284 }
1285 early_initcall(init_hw_perf_events);
1286
1287 /*
1288  * Callchain handling code.
1289  */
1290 struct frame_tail {
1291         struct frame_tail   __user *fp;
1292         unsigned long       lr;
1293 } __attribute__((packed));
1294
1295 /*
1296  * Get the return address for a single stackframe and return a pointer to the
1297  * next frame tail.
1298  */
1299 static struct frame_tail __user *
1300 user_backtrace(struct frame_tail __user *tail,
1301                struct perf_callchain_entry *entry)
1302 {
1303         struct frame_tail buftail;
1304         unsigned long err;
1305
1306         /* Also check accessibility of one struct frame_tail beyond */
1307         if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
1308                 return NULL;
1309
1310         pagefault_disable();
1311         err = __copy_from_user_inatomic(&buftail, tail, sizeof(buftail));
1312         pagefault_enable();
1313
1314         if (err)
1315                 return NULL;
1316
1317         perf_callchain_store(entry, buftail.lr);
1318
1319         /*
1320          * Frame pointers should strictly progress back up the stack
1321          * (towards higher addresses).
1322          */
1323         if (tail >= buftail.fp)
1324                 return NULL;
1325
1326         return buftail.fp;
1327 }
1328
1329 void perf_callchain_user(struct perf_callchain_entry *entry,
1330                          struct pt_regs *regs)
1331 {
1332         struct frame_tail __user *tail;
1333
1334         tail = (struct frame_tail __user *)regs->regs[29];
1335
1336         while (entry->nr < PERF_MAX_STACK_DEPTH &&
1337                tail && !((unsigned long)tail & 0xf))
1338                 tail = user_backtrace(tail, entry);
1339 }
1340
1341 /*
1342  * Gets called by walk_stackframe() for every stackframe. This will be called
1343  * whist unwinding the stackframe and is like a subroutine return so we use
1344  * the PC.
1345  */
1346 static int callchain_trace(struct stackframe *frame, void *data)
1347 {
1348         struct perf_callchain_entry *entry = data;
1349         perf_callchain_store(entry, frame->pc);
1350         return 0;
1351 }
1352
1353 void perf_callchain_kernel(struct perf_callchain_entry *entry,
1354                            struct pt_regs *regs)
1355 {
1356         struct stackframe frame;
1357
1358         frame.fp = regs->regs[29];
1359         frame.sp = regs->sp;
1360         frame.pc = regs->pc;
1361         walk_stackframe(&frame, callchain_trace, entry);
1362 }