arch/x86/kernel/cpu/perf_event.c

   1 /*
   2  * Performance events x86 architecture code
   3  *
   4  *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
   5  *  Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
   6  *  Copyright (C) 2009 Jaswinder Singh Rajput
   7  *  Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
   8  *  Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
   9  *  Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com>
  10  *  Copyright (C) 2009 Google, Inc., Stephane Eranian
  11  *
  12  *  For licencing details see kernel-base/COPYING
  13  */
  14
  15 #include <linux/perf_event.h>
  16 #include <linux/capability.h>
  17 #include <linux/notifier.h>
  18 #include <linux/hardirq.h>
  19 #include <linux/kprobes.h>
  20 #include <linux/module.h>
  21 #include <linux/kdebug.h>
  22 #include <linux/sched.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/slab.h>
  25 #include <linux/highmem.h>
  26 #include <linux/cpu.h>
  27 #include <linux/bitops.h>
  28
  29 #include <asm/apic.h>
  30 #include <asm/stacktrace.h>
  31 #include <asm/nmi.h>
  32 #include <asm/compat.h>
  33
  34 #if 0
  35 #undef wrmsrl
  36 #define wrmsrl(msr, val)                                        \
  37 do {                                                            \
  38         trace_printk("wrmsrl(%lx, %lx)\n", (unsigned long)(msr),\
  39                         (unsigned long)(val));                  \
  40         native_write_msr((msr), (u32)((u64)(val)),              \
  41                         (u32)((u64)(val) >> 32));               \
  42 } while (0)
  43 #endif
  44
  45 /*
  46  * best effort, GUP based copy_from_user() that assumes IRQ or NMI context
  47  */
  48 static unsigned long
  49 copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
  50 {
  51         unsigned long offset, addr = (unsigned long)from;
  52         unsigned long size, len = 0;
  53         struct page *page;
  54         void *map;
  55         int ret;
  56
  57         do {
  58                 ret = __get_user_pages_fast(addr, 1, 0, &page);
  59                 if (!ret)
  60                         break;
  61
  62                 offset = addr & (PAGE_SIZE - 1);
  63                 size = min(PAGE_SIZE - offset, n - len);
  64
  65                 map = kmap_atomic(page);
  66                 memcpy(to, map+offset, size);
  67                 kunmap_atomic(map);
  68                 put_page(page);
  69
  70                 len  += size;
  71                 to   += size;
  72                 addr += size;
  73
  74         } while (len < n);
  75
  76         return len;
  77 }
  78
  79 struct event_constraint {
  80         union {
  81                 unsigned long   idxmsk[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
  82                 u64             idxmsk64;
  83         };
  84         u64     code;
  85         u64     cmask;
  86         int     weight;
  87 };
  88
  89 struct amd_nb {
  90         int nb_id;  /* NorthBridge id */
  91         int refcnt; /* reference count */
  92         struct perf_event *owners[X86_PMC_IDX_MAX];
  93         struct event_constraint event_constraints[X86_PMC_IDX_MAX];
  94 };
  95
  96 #define MAX_LBR_ENTRIES         16
  97
  98 struct cpu_hw_events {
  99         /*
 100          * Generic x86 PMC bits
 101          */
 102         struct perf_event       *events[X86_PMC_IDX_MAX]; /* in counter order */
 103         unsigned long           active_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
 104         unsigned long           running[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
 105         int                     enabled;
 106
 107         int                     n_events;
 108         int                     n_added;
 109         int                     n_txn;
 110         int                     assign[X86_PMC_IDX_MAX]; /* event to counter assignment */
 111         u64                     tags[X86_PMC_IDX_MAX];
 112         struct perf_event       *event_list[X86_PMC_IDX_MAX]; /* in enabled order */
 113
 114         unsigned int            group_flag;
 115
 116         /*
 117          * Intel DebugStore bits
 118          */
 119         struct debug_store      *ds;
 120         u64                     pebs_enabled;
 121
 122         /*
 123          * Intel LBR bits
 124          */
 125         int                             lbr_users;
 126         void                            *lbr_context;
 127         struct perf_branch_stack        lbr_stack;
 128         struct perf_branch_entry        lbr_entries[MAX_LBR_ENTRIES];
 129
 130         /*
 131          * AMD specific bits
 132          */
 133         struct amd_nb           *amd_nb;
 134 };
 135
 136 #define __EVENT_CONSTRAINT(c, n, m, w) {\
 137         { .idxmsk64 = (n) },            \
 138         .code = (c),                    \
 139         .cmask = (m),                   \
 140         .weight = (w),                  \
 141 }
 142
 143 #define EVENT_CONSTRAINT(c, n, m)       \
 144         __EVENT_CONSTRAINT(c, n, m, HWEIGHT(n))
 145
 146 /*
 147  * Constraint on the Event code.
 148  */
 149 #define INTEL_EVENT_CONSTRAINT(c, n)    \
 150         EVENT_CONSTRAINT(c, n, ARCH_PERFMON_EVENTSEL_EVENT)
 151
 152 /*
 153  * Constraint on the Event code + UMask + fixed-mask
 154  *
 155  * filter mask to validate fixed counter events.
 156  * the following filters disqualify for fixed counters:
 157  *  - inv
 158  *  - edge
 159  *  - cnt-mask
 160  *  The other filters are supported by fixed counters.
 161  *  The any-thread option is supported starting with v3.
 162  */
 163 #define FIXED_EVENT_CONSTRAINT(c, n)    \
 164         EVENT_CONSTRAINT(c, (1ULL << (32+n)), X86_RAW_EVENT_MASK)
 165
 166 /*
 167  * Constraint on the Event code + UMask
 168  */
 169 #define PEBS_EVENT_CONSTRAINT(c, n)     \
 170         EVENT_CONSTRAINT(c, n, INTEL_ARCH_EVENT_MASK)
 171
 172 #define EVENT_CONSTRAINT_END            \
 173         EVENT_CONSTRAINT(0, 0, 0)
 174
 175 #define for_each_event_constraint(e, c) \
 176         for ((e) = (c); (e)->weight; (e)++)
 177
 178 union perf_capabilities {
 179         struct {
 180                 u64     lbr_format    : 6;
 181                 u64     pebs_trap     : 1;
 182                 u64     pebs_arch_reg : 1;
 183                 u64     pebs_format   : 4;
 184                 u64     smm_freeze    : 1;
 185         };
 186         u64     capabilities;
 187 };
 188
 189 /*
 190  * struct x86_pmu - generic x86 pmu
 191  */
 192 struct x86_pmu {
 193         /*
 194          * Generic x86 PMC bits
 195          */
 196         const char      *name;
 197         int             version;
 198         int             (*handle_irq)(struct pt_regs *);
 199         void            (*disable_all)(void);
 200         void            (*enable_all)(int added);
 201         void            (*enable)(struct perf_event *);
 202         void            (*disable)(struct perf_event *);
 203         int             (*hw_config)(struct perf_event *event);
 204         int             (*schedule_events)(struct cpu_hw_events *cpuc, int n, int *assign);
 205         unsigned        eventsel;
 206         unsigned        perfctr;
 207         u64             (*event_map)(int);
 208         int             max_events;
 209         int             num_counters;
 210         int             num_counters_fixed;
 211         int             cntval_bits;
 212         u64             cntval_mask;
 213         int             apic;
 214         u64             max_period;
 215         struct event_constraint *
 216                         (*get_event_constraints)(struct cpu_hw_events *cpuc,
 217                                                  struct perf_event *event);
 218
 219         void            (*put_event_constraints)(struct cpu_hw_events *cpuc,
 220                                                  struct perf_event *event);
 221         struct event_constraint *event_constraints;
 222         void            (*quirks)(void);
 223         int             perfctr_second_write;
 224
 225         int             (*cpu_prepare)(int cpu);
 226         void            (*cpu_starting)(int cpu);
 227         void            (*cpu_dying)(int cpu);
 228         void            (*cpu_dead)(int cpu);
 229
 230         /*
 231          * Intel Arch Perfmon v2+
 232          */
 233         u64                     intel_ctrl;
 234         union perf_capabilities intel_cap;
 235
 236         /*
 237          * Intel DebugStore bits
 238          */
 239         int             bts, pebs;
 240         int             bts_active, pebs_active;
 241         int             pebs_record_size;
 242         void            (*drain_pebs)(struct pt_regs *regs);
 243         struct event_constraint *pebs_constraints;
 244
 245         /*
 246          * Intel LBR
 247          */
 248         unsigned long   lbr_tos, lbr_from, lbr_to; /* MSR base regs       */
 249         int             lbr_nr;                    /* hardware stack size */
 250 };
 251
 252 static struct x86_pmu x86_pmu __read_mostly;
 253
 254 static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
 255         .enabled = 1,
 256 };
 257
 258 static int x86_perf_event_set_period(struct perf_event *event);
 259
 260 /*
 261  * Generalized hw caching related hw_event table, filled
 262  * in on a per model basis. A value of 0 means
 263  * 'not supported', -1 means 'hw_event makes no sense on
 264  * this CPU', any other value means the raw hw_event
 265  * ID.
 266  */
 267
 268 #define C(x) PERF_COUNT_HW_CACHE_##x
 269
 270 static u64 __read_mostly hw_cache_event_ids
 271                                 [PERF_COUNT_HW_CACHE_MAX]
 272                                 [PERF_COUNT_HW_CACHE_OP_MAX]
 273                                 [PERF_COUNT_HW_CACHE_RESULT_MAX];
 274
 275 /*
 276  * Propagate event elapsed time into the generic event.
 277  * Can only be executed on the CPU where the event is active.
 278  * Returns the delta events processed.
 279  */
 280 static u64
 281 x86_perf_event_update(struct perf_event *event)
 282 {
 283         struct hw_perf_event *hwc = &event->hw;
 284         int shift = 64 - x86_pmu.cntval_bits;
 285         u64 prev_raw_count, new_raw_count;
 286         int idx = hwc->idx;
 287         s64 delta;
 288
 289         if (idx == X86_PMC_IDX_FIXED_BTS)
 290                 return 0;
 291
 292         /*
 293          * Careful: an NMI might modify the previous event value.
 294          *
 295          * Our tactic to handle this is to first atomically read and
 296          * exchange a new raw count - then add that new-prev delta
 297          * count to the generic event atomically:
 298          */
 299 again:
 300         prev_raw_count = local64_read(&hwc->prev_count);
 301         rdmsrl(hwc->event_base + idx, new_raw_count);
 302
 303         if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
 304                                         new_raw_count) != prev_raw_count)
 305                 goto again;
 306
 307         /*
 308          * Now we have the new raw value and have updated the prev
 309          * timestamp already. We can now calculate the elapsed delta
 310          * (event-)time and add that to the generic event.
 311          *
 312          * Careful, not all hw sign-extends above the physical width
 313          * of the count.
 314          */
 315         delta = (new_raw_count << shift) - (prev_raw_count << shift);
 316         delta >>= shift;
 317
 318         local64_add(delta, &event->count);
 319         local64_sub(delta, &hwc->period_left);
 320
 321         return new_raw_count;
 322 }
 323
 324 static atomic_t active_events;
 325 static DEFINE_MUTEX(pmc_reserve_mutex);
 326
 327 #ifdef CONFIG_X86_LOCAL_APIC
 328
 329 static bool reserve_pmc_hardware(void)
 330 {
 331         int i;
 332
 333         for (i = 0; i < x86_pmu.num_counters; i++) {
 334                 if (!reserve_perfctr_nmi(x86_pmu.perfctr + i))
 335                         goto perfctr_fail;
 336         }
 337
 338         for (i = 0; i < x86_pmu.num_counters; i++) {
 339                 if (!reserve_evntsel_nmi(x86_pmu.eventsel + i))
 340                         goto eventsel_fail;
 341         }
 342
 343         return true;
 344
 345 eventsel_fail:
 346         for (i--; i >= 0; i--)
 347                 release_evntsel_nmi(x86_pmu.eventsel + i);
 348
 349         i = x86_pmu.num_counters;
 350
 351 perfctr_fail:
 352         for (i--; i >= 0; i--)
 353                 release_perfctr_nmi(x86_pmu.perfctr + i);
 354
 355         return false;
 356 }
 357
 358 static void release_pmc_hardware(void)
 359 {
 360         int i;
 361
 362         for (i = 0; i < x86_pmu.num_counters; i++) {
 363                 release_perfctr_nmi(x86_pmu.perfctr + i);
 364                 release_evntsel_nmi(x86_pmu.eventsel + i);
 365         }
 366 }
 367
 368 #else
 369
 370 static bool reserve_pmc_hardware(void) { return true; }
 371 static void release_pmc_hardware(void) {}
 372
 373 #endif
 374
 375 static bool check_hw_exists(void)
 376 {
 377         u64 val, val_new = 0;
 378         int i, reg, ret = 0;
 379
 380         /*
 381          * Check to see if the BIOS enabled any of the counters, if so
 382          * complain and bail.
 383          */
 384         for (i = 0; i < x86_pmu.num_counters; i++) {
 385                 reg = x86_pmu.eventsel + i;
 386                 ret = rdmsrl_safe(reg, &val);
 387                 if (ret)
 388                         goto msr_fail;
 389                 if (val & ARCH_PERFMON_EVENTSEL_ENABLE)
 390                         goto bios_fail;
 391         }
 392
 393         if (x86_pmu.num_counters_fixed) {
 394                 reg = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
 395                 ret = rdmsrl_safe(reg, &val);
 396                 if (ret)
 397                         goto msr_fail;
 398                 for (i = 0; i < x86_pmu.num_counters_fixed; i++) {
 399                         if (val & (0x03 << i*4))
 400                                 goto bios_fail;
 401                 }
 402         }
 403
 404         /*
 405          * Now write a value and read it back to see if it matches,
 406          * this is needed to detect certain hardware emulators (qemu/kvm)
 407          * that don't trap on the MSR access and always return 0s.
 408          */
 409         val = 0xabcdUL;
 410         ret = checking_wrmsrl(x86_pmu.perfctr, val);
 411         ret |= rdmsrl_safe(x86_pmu.perfctr, &val_new);
 412         if (ret || val != val_new)
 413                 goto msr_fail;
 414
 415         return true;
 416
 417 bios_fail:
 418         printk(KERN_CONT "Broken BIOS detected, using software events only.\n");
 419         printk(KERN_ERR FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n", reg, val);
 420         return false;
 421
 422 msr_fail:
 423         printk(KERN_CONT "Broken PMU hardware detected, using software events only.\n");
 424         return false;
 425 }
 426
 427 static void reserve_ds_buffers(void);
 428 static void release_ds_buffers(void);
 429
 430 static void hw_perf_event_destroy(struct perf_event *event)
 431 {
 432         if (atomic_dec_and_mutex_lock(&active_events, &pmc_reserve_mutex)) {
 433                 release_pmc_hardware();
 434                 release_ds_buffers();
 435                 mutex_unlock(&pmc_reserve_mutex);
 436         }
 437 }
 438
 439 static inline int x86_pmu_initialized(void)
 440 {
 441         return x86_pmu.handle_irq != NULL;
 442 }
 443
 444 static inline int
 445 set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event_attr *attr)
 446 {
 447         unsigned int cache_type, cache_op, cache_result;
 448         u64 config, val;
 449
 450         config = attr->config;
 451
 452         cache_type = (config >>  0) & 0xff;
 453         if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
 454                 return -EINVAL;
 455
 456         cache_op = (config >>  8) & 0xff;
 457         if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
 458                 return -EINVAL;
 459
 460         cache_result = (config >> 16) & 0xff;
 461         if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
 462                 return -EINVAL;
 463
 464         val = hw_cache_event_ids[cache_type][cache_op][cache_result];
 465
 466         if (val == 0)
 467                 return -ENOENT;
 468
 469         if (val == -1)
 470                 return -EINVAL;
 471
 472         hwc->config |= val;
 473
 474         return 0;
 475 }
 476
 477 static int x86_setup_perfctr(struct perf_event *event)
 478 {
 479         struct perf_event_attr *attr = &event->attr;
 480         struct hw_perf_event *hwc = &event->hw;
 481         u64 config;
 482
 483         if (!is_sampling_event(event)) {
 484                 hwc->sample_period = x86_pmu.max_period;
 485                 hwc->last_period = hwc->sample_period;
 486                 local64_set(&hwc->period_left, hwc->sample_period);
 487         } else {
 488                 /*
 489                  * If we have a PMU initialized but no APIC
 490                  * interrupts, we cannot sample hardware
 491                  * events (user-space has to fall back and
 492                  * sample via a hrtimer based software event):
 493                  */
 494                 if (!x86_pmu.apic)
 495                         return -EOPNOTSUPP;
 496         }
 497
 498         if (attr->type == PERF_TYPE_RAW)
 499                 return 0;
 500
 501         if (attr->type == PERF_TYPE_HW_CACHE)
 502                 return set_ext_hw_attr(hwc, attr);
 503
 504         if (attr->config >= x86_pmu.max_events)
 505                 return -EINVAL;
 506
 507         /*
 508          * The generic map:
 509          */
 510         config = x86_pmu.event_map(attr->config);
 511
 512         if (config == 0)
 513                 return -ENOENT;
 514
 515         if (config == -1LL)
 516                 return -EINVAL;
 517
 518         /*
 519          * Branch tracing:
 520          */
 521         if ((attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS) &&
 522             (hwc->sample_period == 1)) {
 523                 /* BTS is not supported by this architecture. */
 524                 if (!x86_pmu.bts_active)
 525                         return -EOPNOTSUPP;
 526
 527                 /* BTS is currently only allowed for user-mode. */
 528                 if (!attr->exclude_kernel)
 529                         return -EOPNOTSUPP;
 530         }
 531
 532         hwc->config |= config;
 533
 534         return 0;
 535 }
 536
 537 static int x86_pmu_hw_config(struct perf_event *event)
 538 {
 539         if (event->attr.precise_ip) {
 540                 int precise = 0;
 541
 542                 /* Support for constant skid */
 543                 if (x86_pmu.pebs_active) {
 544                         precise++;
 545
 546                         /* Support for IP fixup */
 547                         if (x86_pmu.lbr_nr)
 548                                 precise++;
 549                 }
 550
 551                 if (event->attr.precise_ip > precise)
 552                         return -EOPNOTSUPP;
 553         }
 554
 555         /*
 556          * Generate PMC IRQs:
 557          * (keep 'enabled' bit clear for now)
 558          */
 559         event->hw.config = ARCH_PERFMON_EVENTSEL_INT;
 560
 561         /*
 562          * Count user and OS events unless requested not to
 563          */
 564         if (!event->attr.exclude_user)
 565                 event->hw.config |= ARCH_PERFMON_EVENTSEL_USR;
 566         if (!event->attr.exclude_kernel)
 567                 event->hw.config |= ARCH_PERFMON_EVENTSEL_OS;
 568
 569         if (event->attr.type == PERF_TYPE_RAW)
 570                 event->hw.config |= event->attr.config & X86_RAW_EVENT_MASK;
 571
 572         return x86_setup_perfctr(event);
 573 }
 574
 575 /*
 576  * Setup the hardware configuration for a given attr_type
 577  */
 578 static int __x86_pmu_event_init(struct perf_event *event)
 579 {
 580         int err;
 581
 582         if (!x86_pmu_initialized())
 583                 return -ENODEV;
 584
 585         err = 0;
 586         if (!atomic_inc_not_zero(&active_events)) {
 587                 mutex_lock(&pmc_reserve_mutex);
 588                 if (atomic_read(&active_events) == 0) {
 589                         if (!reserve_pmc_hardware())
 590                                 err = -EBUSY;
 591                         else
 592                                 reserve_ds_buffers();
 593                 }
 594                 if (!err)
 595                         atomic_inc(&active_events);
 596                 mutex_unlock(&pmc_reserve_mutex);
 597         }
 598         if (err)
 599                 return err;
 600
 601         event->destroy = hw_perf_event_destroy;
 602
 603         event->hw.idx = -1;
 604         event->hw.last_cpu = -1;
 605         event->hw.last_tag = ~0ULL;
 606
 607         return x86_pmu.hw_config(event);
 608 }
 609
 610 static void x86_pmu_disable_all(void)
 611 {
 612         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 613         int idx;
 614
 615         for (idx = 0; idx < x86_pmu.num_counters; idx++) {
 616                 u64 val;
 617
 618                 if (!test_bit(idx, cpuc->active_mask))
 619                         continue;
 620                 rdmsrl(x86_pmu.eventsel + idx, val);
 621                 if (!(val & ARCH_PERFMON_EVENTSEL_ENABLE))
 622                         continue;
 623                 val &= ~ARCH_PERFMON_EVENTSEL_ENABLE;
 624                 wrmsrl(x86_pmu.eventsel + idx, val);
 625         }
 626 }
 627
 628 static void x86_pmu_disable(struct pmu *pmu)
 629 {
 630         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 631
 632         if (!x86_pmu_initialized())
 633                 return;
 634
 635         if (!cpuc->enabled)
 636                 return;
 637
 638         cpuc->n_added = 0;
 639         cpuc->enabled = 0;
 640         barrier();
 641
 642         x86_pmu.disable_all();
 643 }
 644
 645 static void x86_pmu_enable_all(int added)
 646 {
 647         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 648         int idx;
 649
 650         for (idx = 0; idx < x86_pmu.num_counters; idx++) {
 651                 struct perf_event *event = cpuc->events[idx];
 652                 u64 val;
 653
 654                 if (!test_bit(idx, cpuc->active_mask))
 655                         continue;
 656
 657                 val = event->hw.config;
 658                 val |= ARCH_PERFMON_EVENTSEL_ENABLE;
 659                 wrmsrl(x86_pmu.eventsel + idx, val);
 660         }
 661 }
 662
 663 static struct pmu pmu;
 664
 665 static inline int is_x86_event(struct perf_event *event)
 666 {
 667         return event->pmu == &pmu;
 668 }
 669
 670 static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 671 {
 672         struct event_constraint *c, *constraints[X86_PMC_IDX_MAX];
 673         unsigned long used_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
 674         int i, j, w, wmax, num = 0;
 675         struct hw_perf_event *hwc;
 676
 677         bitmap_zero(used_mask, X86_PMC_IDX_MAX);
 678
 679         for (i = 0; i < n; i++) {
 680                 c = x86_pmu.get_event_constraints(cpuc, cpuc->event_list[i]);
 681                 constraints[i] = c;
 682         }
 683
 684         /*
 685          * fastpath, try to reuse previous register
 686          */
 687         for (i = 0; i < n; i++) {
 688                 hwc = &cpuc->event_list[i]->hw;
 689                 c = constraints[i];
 690
 691                 /* never assigned */
 692                 if (hwc->idx == -1)
 693                         break;
 694
 695                 /* constraint still honored */
 696                 if (!test_bit(hwc->idx, c->idxmsk))
 697                         break;
 698
 699                 /* not already used */
 700                 if (test_bit(hwc->idx, used_mask))
 701                         break;
 702
 703                 __set_bit(hwc->idx, used_mask);
 704                 if (assign)
 705                         assign[i] = hwc->idx;
 706         }
 707         if (i == n)
 708                 goto done;
 709
 710         /*
 711          * begin slow path
 712          */
 713
 714         bitmap_zero(used_mask, X86_PMC_IDX_MAX);
 715
 716         /*
 717          * weight = number of possible counters
 718          *
 719          * 1    = most constrained, only works on one counter
 720          * wmax = least constrained, works on any counter
 721          *
 722          * assign events to counters starting with most
 723          * constrained events.
 724          */
 725         wmax = x86_pmu.num_counters;
 726
 727         /*
 728          * when fixed event counters are present,
 729          * wmax is incremented by 1 to account
 730          * for one more choice
 731          */
 732         if (x86_pmu.num_counters_fixed)
 733                 wmax++;
 734
 735         for (w = 1, num = n; num && w <= wmax; w++) {
 736                 /* for each event */
 737                 for (i = 0; num && i < n; i++) {
 738                         c = constraints[i];
 739                         hwc = &cpuc->event_list[i]->hw;
 740
 741                         if (c->weight != w)
 742                                 continue;
 743
 744                         for_each_set_bit(j, c->idxmsk, X86_PMC_IDX_MAX) {
 745                                 if (!test_bit(j, used_mask))
 746                                         break;
 747                         }
 748
 749                         if (j == X86_PMC_IDX_MAX)
 750                                 break;
 751
 752                         __set_bit(j, used_mask);
 753
 754                         if (assign)
 755                                 assign[i] = j;
 756                         num--;
 757                 }
 758         }
 759 done:
 760         /*
 761          * scheduling failed or is just a simulation,
 762          * free resources if necessary
 763          */
 764         if (!assign || num) {
 765                 for (i = 0; i < n; i++) {
 766                         if (x86_pmu.put_event_constraints)
 767                                 x86_pmu.put_event_constraints(cpuc, cpuc->event_list[i]);
 768                 }
 769         }
 770         return num ? -ENOSPC : 0;
 771 }
 772
 773 /*
 774  * dogrp: true if must collect siblings events (group)
 775  * returns total number of events and error code
 776  */
 777 static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader, bool dogrp)
 778 {
 779         struct perf_event *event;
 780         int n, max_count;
 781
 782         max_count = x86_pmu.num_counters + x86_pmu.num_counters_fixed;
 783
 784         /* current number of events already accepted */
 785         n = cpuc->n_events;
 786
 787         if (is_x86_event(leader)) {
 788                 if (n >= max_count)
 789                         return -ENOSPC;
 790                 cpuc->event_list[n] = leader;
 791                 n++;
 792         }
 793         if (!dogrp)
 794                 return n;
 795
 796         list_for_each_entry(event, &leader->sibling_list, group_entry) {
 797                 if (!is_x86_event(event) ||
 798                     event->state <= PERF_EVENT_STATE_OFF)
 799                         continue;
 800
 801                 if (n >= max_count)
 802                         return -ENOSPC;
 803
 804                 cpuc->event_list[n] = event;
 805                 n++;
 806         }
 807         return n;
 808 }
 809
 810 static inline void x86_assign_hw_event(struct perf_event *event,
 811                                 struct cpu_hw_events *cpuc, int i)
 812 {
 813         struct hw_perf_event *hwc = &event->hw;
 814
 815         hwc->idx = cpuc->assign[i];
 816         hwc->last_cpu = smp_processor_id();
 817         hwc->last_tag = ++cpuc->tags[i];
 818
 819         if (hwc->idx == X86_PMC_IDX_FIXED_BTS) {
 820                 hwc->config_base = 0;
 821                 hwc->event_base = 0;
 822         } else if (hwc->idx >= X86_PMC_IDX_FIXED) {
 823                 hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
 824                 /*
 825                  * We set it so that event_base + idx in wrmsr/rdmsr maps to
 826                  * MSR_ARCH_PERFMON_FIXED_CTR0 ... CTR2:
 827                  */
 828                 hwc->event_base =
 829                         MSR_ARCH_PERFMON_FIXED_CTR0 - X86_PMC_IDX_FIXED;
 830         } else {
 831                 hwc->config_base = x86_pmu.eventsel;
 832                 hwc->event_base  = x86_pmu.perfctr;
 833         }
 834 }
 835
 836 static inline int match_prev_assignment(struct hw_perf_event *hwc,
 837                                         struct cpu_hw_events *cpuc,
 838                                         int i)
 839 {
 840         return hwc->idx == cpuc->assign[i] &&
 841                 hwc->last_cpu == smp_processor_id() &&
 842                 hwc->last_tag == cpuc->tags[i];
 843 }
 844
 845 static void x86_pmu_start(struct perf_event *event, int flags);
 846 static void x86_pmu_stop(struct perf_event *event, int flags);
 847
 848 static void x86_pmu_enable(struct pmu *pmu)
 849 {
 850         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 851         struct perf_event *event;
 852         struct hw_perf_event *hwc;
 853         int i, added = cpuc->n_added;
 854
 855         if (!x86_pmu_initialized())
 856                 return;
 857
 858         if (cpuc->enabled)
 859                 return;
 860
 861         if (cpuc->n_added) {
 862                 int n_running = cpuc->n_events - cpuc->n_added;
 863                 /*
 864                  * apply assignment obtained either from
 865                  * hw_perf_group_sched_in() or x86_pmu_enable()
 866                  *
 867                  * step1: save events moving to new counters
 868                  * step2: reprogram moved events into new counters
 869                  */
 870                 for (i = 0; i < n_running; i++) {
 871                         event = cpuc->event_list[i];
 872                         hwc = &event->hw;
 873
 874                         /*
 875                          * we can avoid reprogramming counter if:
 876                          * - assigned same counter as last time
 877                          * - running on same CPU as last time
 878                          * - no other event has used the counter since
 879                          */
 880                         if (hwc->idx == -1 ||
 881                             match_prev_assignment(hwc, cpuc, i))
 882                                 continue;
 883
 884                         /*
 885                          * Ensure we don't accidentally enable a stopped
 886                          * counter simply because we rescheduled.
 887                          */
 888                         if (hwc->state & PERF_HES_STOPPED)
 889                                 hwc->state |= PERF_HES_ARCH;
 890
 891                         x86_pmu_stop(event, PERF_EF_UPDATE);
 892                 }
 893
 894                 for (i = 0; i < cpuc->n_events; i++) {
 895                         event = cpuc->event_list[i];
 896                         hwc = &event->hw;
 897
 898                         if (!match_prev_assignment(hwc, cpuc, i))
 899                                 x86_assign_hw_event(event, cpuc, i);
 900                         else if (i < n_running)
 901                                 continue;
 902
 903                         if (hwc->state & PERF_HES_ARCH)
 904                                 continue;
 905
 906                         x86_pmu_start(event, PERF_EF_RELOAD);
 907                 }
 908                 cpuc->n_added = 0;
 909                 perf_events_lapic_init();
 910         }
 911
 912         cpuc->enabled = 1;
 913         barrier();
 914
 915         x86_pmu.enable_all(added);
 916 }
 917
 918 static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc,
 919                                           u64 enable_mask)
 920 {
 921         wrmsrl(hwc->config_base + hwc->idx, hwc->config | enable_mask);
 922 }
 923
 924 static inline void x86_pmu_disable_event(struct perf_event *event)
 925 {
 926         struct hw_perf_event *hwc = &event->hw;
 927
 928         wrmsrl(hwc->config_base + hwc->idx, hwc->config);
 929 }
 930
 931 static DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left);
 932
 933 /*
 934  * Set the next IRQ period, based on the hwc->period_left value.
 935  * To be called with the event disabled in hw:
 936  */
 937 static int
 938 x86_perf_event_set_period(struct perf_event *event)
 939 {
 940         struct hw_perf_event *hwc = &event->hw;
 941         s64 left = local64_read(&hwc->period_left);
 942         s64 period = hwc->sample_period;
 943         int ret = 0, idx = hwc->idx;
 944
 945         if (idx == X86_PMC_IDX_FIXED_BTS)
 946                 return 0;
 947
 948         /*
 949          * If we are way outside a reasonable range then just skip forward:
 950          */
 951         if (unlikely(left <= -period)) {
 952                 left = period;
 953                 local64_set(&hwc->period_left, left);
 954                 hwc->last_period = period;
 955                 ret = 1;
 956         }
 957
 958         if (unlikely(left <= 0)) {
 959                 left += period;
 960                 local64_set(&hwc->period_left, left);
 961                 hwc->last_period = period;
 962                 ret = 1;
 963         }
 964         /*
 965          * Quirk: certain CPUs dont like it if just 1 hw_event is left:
 966          */
 967         if (unlikely(left < 2))
 968                 left = 2;
 969
 970         if (left > x86_pmu.max_period)
 971                 left = x86_pmu.max_period;
 972
 973         per_cpu(pmc_prev_left[idx], smp_processor_id()) = left;
 974
 975         /*
 976          * The hw event starts counting from this event offset,
 977          * mark it to be able to extra future deltas:
 978          */
 979         local64_set(&hwc->prev_count, (u64)-left);
 980
 981         wrmsrl(hwc->event_base + idx, (u64)(-left) & x86_pmu.cntval_mask);
 982
 983         /*
 984          * Due to erratum on certan cpu we need
 985          * a second write to be sure the register
 986          * is updated properly
 987          */
 988         if (x86_pmu.perfctr_second_write) {
 989                 wrmsrl(hwc->event_base + idx,
 990                         (u64)(-left) & x86_pmu.cntval_mask);
 991         }
 992
 993         perf_event_update_userpage(event);
 994
 995         return ret;
 996 }
 997
 998 static void x86_pmu_enable_event(struct perf_event *event)
 999 {
1000         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
1001         if (cpuc->enabled)
1002                 __x86_pmu_enable_event(&event->hw,
1003                                        ARCH_PERFMON_EVENTSEL_ENABLE);
1004 }
1005
1006 /*
1007  * Add a single event to the PMU.
1008  *
1009  * The event is added to the group of enabled events
1010  * but only if it can be scehduled with existing events.
1011  */
1012 static int x86_pmu_add(struct perf_event *event, int flags)
1013 {
1014         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
1015         struct hw_perf_event *hwc;
1016         int assign[X86_PMC_IDX_MAX];
1017         int n, n0, ret;
1018
1019         hwc = &event->hw;
1020
1021         perf_pmu_disable(event->pmu);
1022         n0 = cpuc->n_events;
1023         ret = n = collect_events(cpuc, event, false);
1024         if (ret < 0)
1025                 goto out;
1026
1027         hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
1028         if (!(flags & PERF_EF_START))
1029                 hwc->state |= PERF_HES_ARCH;
1030
1031         /*
1032          * If group events scheduling transaction was started,
1033          * skip the schedulability test here, it will be peformed
1034          * at commit time (->commit_txn) as a whole
1035          */
1036         if (cpuc->group_flag & PERF_EVENT_TXN)
1037                 goto done_collect;
1038
1039         ret = x86_pmu.schedule_events(cpuc, n, assign);
1040         if (ret)
1041                 goto out;
1042         /*
1043          * copy new assignment, now we know it is possible
1044          * will be used by hw_perf_enable()
1045          */
1046         memcpy(cpuc->assign, assign, n*sizeof(int));
1047
1048 done_collect:
1049         cpuc->n_events = n;
1050         cpuc->n_added += n - n0;
1051         cpuc->n_txn += n - n0;
1052
1053         ret = 0;
1054 out:
1055         perf_pmu_enable(event->pmu);
1056         return ret;
1057 }
1058
1059 static void x86_pmu_start(struct perf_event *event, int flags)
1060 {
1061         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
1062         int idx = event->hw.idx;
1063
1064         if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
1065                 return;
1066
1067         if (WARN_ON_ONCE(idx == -1))
1068                 return;
1069
1070         if (flags & PERF_EF_RELOAD) {
1071                 WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
1072                 x86_perf_event_set_period(event);
1073         }
1074
1075         event->hw.state = 0;
1076
1077         cpuc->events[idx] = event;
1078         __set_bit(idx, cpuc->active_mask);
1079         __set_bit(idx, cpuc->running);
1080         x86_pmu.enable(event);
1081         perf_event_update_userpage(event);
1082 }
1083
1084 void perf_event_print_debug(void)
1085 {
1086         u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
1087         u64 pebs;
1088         struct cpu_hw_events *cpuc;
1089         unsigned long flags;
1090         int cpu, idx;
1091
1092         if (!x86_pmu.num_counters)
1093                 return;
1094
1095         local_irq_save(flags);
1096
1097         cpu = smp_processor_id();
1098         cpuc = &per_cpu(cpu_hw_events, cpu);
1099
1100         if (x86_pmu.version >= 2) {
1101                 rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
1102                 rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
1103                 rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow);
1104                 rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed);
1105                 rdmsrl(MSR_IA32_PEBS_ENABLE, pebs);
1106
1107                 pr_info("\n");
1108                 pr_info("CPU#%d: ctrl:       %016llx\n", cpu, ctrl);
1109                 pr_info("CPU#%d: status:     %016llx\n", cpu, status);
1110                 pr_info("CPU#%d: overflow:   %016llx\n", cpu, overflow);
1111                 pr_info("CPU#%d: fixed:      %016llx\n", cpu, fixed);
1112                 pr_info("CPU#%d: pebs:       %016llx\n", cpu, pebs);
1113         }
1114         pr_info("CPU#%d: active:     %016llx\n", cpu, *(u64 *)cpuc->active_mask);
1115
1116         for (idx = 0; idx < x86_pmu.num_counters; idx++) {
1117                 rdmsrl(x86_pmu.eventsel + idx, pmc_ctrl);
1118                 rdmsrl(x86_pmu.perfctr  + idx, pmc_count);
1119
1120                 prev_left = per_cpu(pmc_prev_left[idx], cpu);
1121
1122                 pr_info("CPU#%d:   gen-PMC%d ctrl:  %016llx\n",
1123                         cpu, idx, pmc_ctrl);
1124                 pr_info("CPU#%d:   gen-PMC%d count: %016llx\n",
1125                         cpu, idx, pmc_count);
1126                 pr_info("CPU#%d:   gen-PMC%d left:  %016llx\n",
1127                         cpu, idx, prev_left);
1128         }
1129         for (idx = 0; idx < x86_pmu.num_counters_fixed; idx++) {
1130                 rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR0 + idx, pmc_count);
1131
1132                 pr_info("CPU#%d: fixed-PMC%d count: %016llx\n",
1133                         cpu, idx, pmc_count);
1134         }
1135         local_irq_restore(flags);
1136 }
1137
1138 static void x86_pmu_stop(struct perf_event *event, int flags)
1139 {
1140         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
1141         struct hw_perf_event *hwc = &event->hw;
1142
1143         if (__test_and_clear_bit(hwc->idx, cpuc->active_mask)) {
1144                 x86_pmu.disable(event);
1145                 cpuc->events[hwc->idx] = NULL;
1146                 WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
1147                 hwc->state |= PERF_HES_STOPPED;
1148         }
1149
1150         if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
1151                 /*
1152                  * Drain the remaining delta count out of a event
1153                  * that we are disabling:
1154                  */
1155                 x86_perf_event_update(event);
1156                 hwc->state |= PERF_HES_UPTODATE;
1157         }
1158 }
1159
1160 static void x86_pmu_del(struct perf_event *event, int flags)
1161 {
1162         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
1163         int i;
1164
1165         /*
1166          * If we're called during a txn, we don't need to do anything.
1167          * The events never got scheduled and ->cancel_txn will truncate
1168          * the event_list.
1169          */
1170         if (cpuc->group_flag & PERF_EVENT_TXN)
1171                 return;
1172
1173         x86_pmu_stop(event, PERF_EF_UPDATE);
1174
1175         for (i = 0; i < cpuc->n_events; i++) {
1176                 if (event == cpuc->event_list[i]) {
1177
1178                         if (x86_pmu.put_event_constraints)
1179                                 x86_pmu.put_event_constraints(cpuc, event);
1180
1181                         while (++i < cpuc->n_events)
1182                                 cpuc->event_list[i-1] = cpuc->event_list[i];
1183
1184                         --cpuc->n_events;
1185                         break;
1186                 }
1187         }
1188         perf_event_update_userpage(event);
1189 }
1190
1191 static int x86_pmu_handle_irq(struct pt_regs *regs)
1192 {
1193         struct perf_sample_data data;
1194         struct cpu_hw_events *cpuc;
1195         struct perf_event *event;
1196         int idx, handled = 0;
1197         u64 val;
1198
1199         perf_sample_data_init(&data, 0);
1200
1201         cpuc = &__get_cpu_var(cpu_hw_events);
1202
1203         for (idx = 0; idx < x86_pmu.num_counters; idx++) {
1204                 if (!test_bit(idx, cpuc->active_mask)) {
1205                         /*
1206                          * Though we deactivated the counter some cpus
1207                          * might still deliver spurious interrupts still
1208                          * in flight. Catch them:
1209                          */
1210                         if (__test_and_clear_bit(idx, cpuc->running))
1211                                 handled++;
1212                         continue;
1213                 }
1214
1215                 event = cpuc->events[idx];
1216
1217                 val = x86_perf_event_update(event);
1218                 if (val & (1ULL << (x86_pmu.cntval_bits - 1)))
1219                         continue;
1220
1221                 /*
1222                  * event overflow
1223                  */
1224                 handled++;
1225                 data.period     = event->hw.last_period;
1226
1227                 if (!x86_perf_event_set_period(event))
1228                         continue;
1229
1230                 if (perf_event_overflow(event, 1, &data, regs))
1231                         x86_pmu_stop(event, 0);
1232         }
1233
1234         if (handled)
1235                 inc_irq_stat(apic_perf_irqs);
1236
1237         return handled;
1238 }
1239
1240 void perf_events_lapic_init(void)
1241 {
1242         if (!x86_pmu.apic || !x86_pmu_initialized())
1243                 return;
1244
1245         /*
1246          * Always use NMI for PMU
1247          */
1248         apic_write(APIC_LVTPC, APIC_DM_NMI);
1249 }
1250
1251 struct pmu_nmi_state {
1252         unsigned int    marked;
1253         int             handled;
1254 };
1255
1256 static DEFINE_PER_CPU(struct pmu_nmi_state, pmu_nmi);
1257
1258 static int __kprobes
1259 perf_event_nmi_handler(struct notifier_block *self,
1260                          unsigned long cmd, void *__args)
1261 {
1262         struct die_args *args = __args;
1263         unsigned int this_nmi;
1264         int handled;
1265
1266         if (!atomic_read(&active_events))
1267                 return NOTIFY_DONE;
1268
1269         switch (cmd) {
1270         case DIE_NMI:
1271         case DIE_NMI_IPI:
1272                 break;
1273         case DIE_NMIUNKNOWN:
1274                 this_nmi = percpu_read(irq_stat.__nmi_count);
1275                 if (this_nmi != __get_cpu_var(pmu_nmi).marked)
1276                         /* let the kernel handle the unknown nmi */
1277                         return NOTIFY_DONE;
1278                 /*
1279                  * This one is a PMU back-to-back nmi. Two events
1280                  * trigger 'simultaneously' raising two back-to-back
1281                  * NMIs. If the first NMI handles both, the latter
1282                  * will be empty and daze the CPU. So, we drop it to
1283                  * avoid false-positive 'unknown nmi' messages.
1284                  */
1285                 return NOTIFY_STOP;
1286         default:
1287                 return NOTIFY_DONE;
1288         }
1289
1290         apic_write(APIC_LVTPC, APIC_DM_NMI);
1291
1292         handled = x86_pmu.handle_irq(args->regs);
1293         if (!handled)
1294                 return NOTIFY_DONE;
1295
1296         this_nmi = percpu_read(irq_stat.__nmi_count);
1297         if ((handled > 1) ||
1298                 /* the next nmi could be a back-to-back nmi */
1299             ((__get_cpu_var(pmu_nmi).marked == this_nmi) &&
1300              (__get_cpu_var(pmu_nmi).handled > 1))) {
1301                 /*
1302                  * We could have two subsequent back-to-back nmis: The
1303                  * first handles more than one counter, the 2nd
1304                  * handles only one counter and the 3rd handles no
1305                  * counter.
1306                  *
1307                  * This is the 2nd nmi because the previous was
1308                  * handling more than one counter. We will mark the
1309                  * next (3rd) and then drop it if unhandled.
1310                  */
1311                 __get_cpu_var(pmu_nmi).marked   = this_nmi + 1;
1312                 __get_cpu_var(pmu_nmi).handled  = handled;
1313         }
1314
1315         return NOTIFY_STOP;
1316 }
1317
1318 static __read_mostly struct notifier_block perf_event_nmi_notifier = {
1319         .notifier_call          = perf_event_nmi_handler,
1320         .next                   = NULL,
1321         .priority               = 1
1322 };
1323
1324 static struct event_constraint unconstrained;
1325 static struct event_constraint emptyconstraint;
1326
1327 static struct event_constraint *
1328 x86_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event)
1329 {
1330         struct event_constraint *c;
1331
1332         if (x86_pmu.event_constraints) {
1333                 for_each_event_constraint(c, x86_pmu.event_constraints) {
1334                         if ((event->hw.config & c->cmask) == c->code)
1335                                 return c;
1336                 }
1337         }
1338
1339         return &unconstrained;
1340 }
1341
1342 #include "perf_event_amd.c"
1343 #include "perf_event_p6.c"
1344 #include "perf_event_p4.c"
1345 #include "perf_event_intel_lbr.c"
1346 #include "perf_event_intel_ds.c"
1347 #include "perf_event_intel.c"
1348
1349 static int __cpuinit
1350 x86_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
1351 {
1352         unsigned int cpu = (long)hcpu;
1353         int ret = NOTIFY_OK;
1354
1355         switch (action & ~CPU_TASKS_FROZEN) {
1356         case CPU_UP_PREPARE:
1357                 if (x86_pmu.cpu_prepare)
1358                         ret = x86_pmu.cpu_prepare(cpu);
1359                 break;
1360
1361         case CPU_STARTING:
1362                 if (x86_pmu.cpu_starting)
1363                         x86_pmu.cpu_starting(cpu);
1364                 break;
1365
1366         case CPU_DYING:
1367                 if (x86_pmu.cpu_dying)
1368                         x86_pmu.cpu_dying(cpu);
1369                 break;
1370
1371         case CPU_UP_CANCELED:
1372         case CPU_DEAD:
1373                 if (x86_pmu.cpu_dead)
1374                         x86_pmu.cpu_dead(cpu);
1375                 break;
1376
1377         default:
1378                 break;
1379         }
1380
1381         return ret;
1382 }
1383
1384 static void __init pmu_check_apic(void)
1385 {
1386         if (cpu_has_apic)
1387                 return;
1388
1389         x86_pmu.apic = 0;
1390         pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n");
1391         pr_info("no hardware sampling interrupt available.\n");
1392 }
1393
1394 int __init init_hw_perf_events(void)
1395 {
1396         struct event_constraint *c;
1397         int err;
1398
1399         pr_info("Performance Events: ");
1400
1401         switch (boot_cpu_data.x86_vendor) {
1402         case X86_VENDOR_INTEL:
1403                 err = intel_pmu_init();
1404                 break;
1405         case X86_VENDOR_AMD:
1406                 err = amd_pmu_init();
1407                 break;
1408         default:
1409                 return 0;
1410         }
1411         if (err != 0) {
1412                 pr_cont("no PMU driver, software events only.\n");
1413                 return 0;
1414         }
1415
1416         pmu_check_apic();
1417
1418         /* sanity check that the hardware exists or is emulated */
1419         if (!check_hw_exists())
1420                 return 0;
1421
1422         pr_cont("%s PMU driver.\n", x86_pmu.name);
1423
1424         if (x86_pmu.quirks)
1425                 x86_pmu.quirks();
1426
1427         if (x86_pmu.num_counters > X86_PMC_MAX_GENERIC) {
1428                 WARN(1, KERN_ERR "hw perf events %d > max(%d), clipping!",
1429                      x86_pmu.num_counters, X86_PMC_MAX_GENERIC);
1430                 x86_pmu.num_counters = X86_PMC_MAX_GENERIC;
1431         }
1432         x86_pmu.intel_ctrl = (1 << x86_pmu.num_counters) - 1;
1433
1434         if (x86_pmu.num_counters_fixed > X86_PMC_MAX_FIXED) {
1435                 WARN(1, KERN_ERR "hw perf events fixed %d > max(%d), clipping!",
1436                      x86_pmu.num_counters_fixed, X86_PMC_MAX_FIXED);
1437                 x86_pmu.num_counters_fixed = X86_PMC_MAX_FIXED;
1438         }
1439
1440         x86_pmu.intel_ctrl |=
1441                 ((1LL << x86_pmu.num_counters_fixed)-1) << X86_PMC_IDX_FIXED;
1442
1443         perf_events_lapic_init();
1444         register_die_notifier(&perf_event_nmi_notifier);
1445
1446         unconstrained = (struct event_constraint)
1447                 __EVENT_CONSTRAINT(0, (1ULL << x86_pmu.num_counters) - 1,
1448                                    0, x86_pmu.num_counters);
1449
1450         if (x86_pmu.event_constraints) {
1451                 for_each_event_constraint(c, x86_pmu.event_constraints) {
1452                         if (c->cmask != X86_RAW_EVENT_MASK)
1453                                 continue;
1454
1455                         c->idxmsk64 |= (1ULL << x86_pmu.num_counters) - 1;
1456                         c->weight += x86_pmu.num_counters;
1457                 }
1458         }
1459
1460         pr_info("... version:                %d\n",     x86_pmu.version);
1461         pr_info("... bit width:              %d\n",     x86_pmu.cntval_bits);
1462         pr_info("... generic registers:      %d\n",     x86_pmu.num_counters);
1463         pr_info("... value mask:             %016Lx\n", x86_pmu.cntval_mask);
1464         pr_info("... max period:             %016Lx\n", x86_pmu.max_period);
1465         pr_info("... fixed-purpose events:   %d\n",     x86_pmu.num_counters_fixed);
1466         pr_info("... event mask:             %016Lx\n", x86_pmu.intel_ctrl);
1467
1468         perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
1469         perf_cpu_notifier(x86_pmu_notifier);
1470
1471         return 0;
1472 }
1473 early_initcall(init_hw_perf_events);
1474
1475 static inline void x86_pmu_read(struct perf_event *event)
1476 {
1477         x86_perf_event_update(event);
1478 }
1479
1480 /*
1481  * Start group events scheduling transaction
1482  * Set the flag to make pmu::enable() not perform the
1483  * schedulability test, it will be performed at commit time
1484  */
1485 static void x86_pmu_start_txn(struct pmu *pmu)
1486 {
1487         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
1488
1489         perf_pmu_disable(pmu);
1490         cpuc->group_flag |= PERF_EVENT_TXN;
1491         cpuc->n_txn = 0;
1492 }
1493
1494 /*
1495  * Stop group events scheduling transaction
1496  * Clear the flag and pmu::enable() will perform the
1497  * schedulability test.
1498  */
1499 static void x86_pmu_cancel_txn(struct pmu *pmu)
1500 {
1501         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
1502
1503         cpuc->group_flag &= ~PERF_EVENT_TXN;
1504         /*
1505          * Truncate the collected events.
1506          */
1507         cpuc->n_added -= cpuc->n_txn;
1508         cpuc->n_events -= cpuc->n_txn;
1509         perf_pmu_enable(pmu);
1510 }
1511
1512 /*
1513  * Commit group events scheduling transaction
1514  * Perform the group schedulability test as a whole
1515  * Return 0 if success
1516  */
1517 static int x86_pmu_commit_txn(struct pmu *pmu)
1518 {
1519         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
1520         int assign[X86_PMC_IDX_MAX];
1521         int n, ret;
1522
1523         n = cpuc->n_events;
1524
1525         if (!x86_pmu_initialized())
1526                 return -EAGAIN;
1527
1528         ret = x86_pmu.schedule_events(cpuc, n, assign);
1529         if (ret)
1530                 return ret;
1531
1532         /*
1533          * copy new assignment, now we know it is possible
1534          * will be used by hw_perf_enable()
1535          */
1536         memcpy(cpuc->assign, assign, n*sizeof(int));
1537
1538         cpuc->group_flag &= ~PERF_EVENT_TXN;
1539         perf_pmu_enable(pmu);
1540         return 0;
1541 }
1542
1543 /*
1544  * validate that we can schedule this event
1545  */
1546 static int validate_event(struct perf_event *event)
1547 {
1548         struct cpu_hw_events *fake_cpuc;
1549         struct event_constraint *c;
1550         int ret = 0;
1551
1552         fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO);
1553         if (!fake_cpuc)
1554                 return -ENOMEM;
1555
1556         c = x86_pmu.get_event_constraints(fake_cpuc, event);
1557
1558         if (!c || !c->weight)
1559                 ret = -ENOSPC;
1560
1561         if (x86_pmu.put_event_constraints)
1562                 x86_pmu.put_event_constraints(fake_cpuc, event);
1563
1564         kfree(fake_cpuc);
1565
1566         return ret;
1567 }
1568
1569 /*
1570  * validate a single event group
1571  *
1572  * validation include:
1573  *      - check events are compatible which each other
1574  *      - events do not compete for the same counter
1575  *      - number of events <= number of counters
1576  *
1577  * validation ensures the group can be loaded onto the
1578  * PMU if it was the only group available.
1579  */
1580 static int validate_group(struct perf_event *event)
1581 {
1582         struct perf_event *leader = event->group_leader;
1583         struct cpu_hw_events *fake_cpuc;
1584         int ret, n;
1585
1586         ret = -ENOMEM;
1587         fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO);
1588         if (!fake_cpuc)
1589                 goto out;
1590
1591         /*
1592          * the event is not yet connected with its
1593          * siblings therefore we must first collect
1594          * existing siblings, then add the new event
1595          * before we can simulate the scheduling
1596          */
1597         ret = -ENOSPC;
1598         n = collect_events(fake_cpuc, leader, true);
1599         if (n < 0)
1600                 goto out_free;
1601
1602         fake_cpuc->n_events = n;
1603         n = collect_events(fake_cpuc, event, false);
1604         if (n < 0)
1605                 goto out_free;
1606
1607         fake_cpuc->n_events = n;
1608
1609         ret = x86_pmu.schedule_events(fake_cpuc, n, NULL);
1610
1611 out_free:
1612         kfree(fake_cpuc);
1613 out:
1614         return ret;
1615 }
1616
1617 int x86_pmu_event_init(struct perf_event *event)
1618 {
1619         struct pmu *tmp;
1620         int err;
1621
1622         switch (event->attr.type) {
1623         case PERF_TYPE_RAW:
1624         case PERF_TYPE_HARDWARE:
1625         case PERF_TYPE_HW_CACHE:
1626                 break;
1627
1628         default:
1629                 return -ENOENT;
1630         }
1631
1632         err = __x86_pmu_event_init(event);
1633         if (!err) {
1634                 /*
1635                  * we temporarily connect event to its pmu
1636                  * such that validate_group() can classify
1637                  * it as an x86 event using is_x86_event()
1638                  */
1639                 tmp = event->pmu;
1640                 event->pmu = &pmu;
1641
1642                 if (event->group_leader != event)
1643                         err = validate_group(event);
1644                 else
1645                         err = validate_event(event);
1646
1647                 event->pmu = tmp;
1648         }
1649         if (err) {
1650                 if (event->destroy)
1651                         event->destroy(event);
1652         }
1653
1654         return err;
1655 }
1656
1657 static struct pmu pmu = {
1658         .pmu_enable     = x86_pmu_enable,
1659         .pmu_disable    = x86_pmu_disable,
1660
1661         .event_init     = x86_pmu_event_init,
1662
1663         .add            = x86_pmu_add,
1664         .del            = x86_pmu_del,
1665         .start          = x86_pmu_start,
1666         .stop           = x86_pmu_stop,
1667         .read           = x86_pmu_read,
1668
1669         .start_txn      = x86_pmu_start_txn,
1670         .cancel_txn     = x86_pmu_cancel_txn,
1671         .commit_txn     = x86_pmu_commit_txn,
1672 };
1673
1674 /*
1675  * callchain support
1676  */
1677
1678 static void
1679 backtrace_warning_symbol(void *data, char *msg, unsigned long symbol)
1680 {
1681         /* Ignore warnings */
1682 }
1683
1684 static void backtrace_warning(void *data, char *msg)
1685 {
1686         /* Ignore warnings */
1687 }
1688
1689 static int backtrace_stack(void *data, char *name)
1690 {
1691         return 0;
1692 }
1693
1694 static void backtrace_address(void *data, unsigned long addr, int reliable)
1695 {
1696         struct perf_callchain_entry *entry = data;
1697
1698         perf_callchain_store(entry, addr);
1699 }
1700
1701 static const struct stacktrace_ops backtrace_ops = {
1702         .warning                = backtrace_warning,
1703         .warning_symbol         = backtrace_warning_symbol,
1704         .stack                  = backtrace_stack,
1705         .address                = backtrace_address,
1706         .walk_stack             = print_context_stack_bp,
1707 };
1708
1709 void
1710 perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
1711 {
1712         if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
1713                 /* TODO: We don't support guest os callchain now */
1714                 return;
1715         }
1716
1717         perf_callchain_store(entry, regs->ip);
1718
1719         dump_trace(NULL, regs, NULL, &backtrace_ops, entry);
1720 }
1721
1722 #ifdef CONFIG_COMPAT
1723 static inline int
1724 perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
1725 {
1726         /* 32-bit process in 64-bit kernel. */
1727         struct stack_frame_ia32 frame;
1728         const void __user *fp;
1729
1730         if (!test_thread_flag(TIF_IA32))
1731                 return 0;
1732
1733         fp = compat_ptr(regs->bp);
1734         while (entry->nr < PERF_MAX_STACK_DEPTH) {
1735                 unsigned long bytes;
1736                 frame.next_frame     = 0;
1737                 frame.return_address = 0;
1738
1739                 bytes = copy_from_user_nmi(&frame, fp, sizeof(frame));
1740                 if (bytes != sizeof(frame))
1741                         break;
1742
1743                 if (fp < compat_ptr(regs->sp))
1744                         break;
1745
1746                 perf_callchain_store(entry, frame.return_address);
1747                 fp = compat_ptr(frame.next_frame);
1748         }
1749         return 1;
1750 }
1751 #else
1752 static inline int
1753 perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
1754 {
1755     return 0;
1756 }
1757 #endif
1758
1759 void
1760 perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
1761 {
1762         struct stack_frame frame;
1763         const void __user *fp;
1764
1765         if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
1766                 /* TODO: We don't support guest os callchain now */
1767                 return;
1768         }
1769
1770         fp = (void __user *)regs->bp;
1771
1772         perf_callchain_store(entry, regs->ip);
1773
1774         if (perf_callchain_user32(regs, entry))
1775                 return;
1776
1777         while (entry->nr < PERF_MAX_STACK_DEPTH) {
1778                 unsigned long bytes;
1779                 frame.next_frame             = NULL;
1780                 frame.return_address = 0;
1781
1782                 bytes = copy_from_user_nmi(&frame, fp, sizeof(frame));
1783                 if (bytes != sizeof(frame))
1784                         break;
1785
1786                 if ((unsigned long)fp < regs->sp)
1787                         break;
1788
1789                 perf_callchain_store(entry, frame.return_address);
1790                 fp = frame.next_frame;
1791         }
1792 }
1793
1794 unsigned long perf_instruction_pointer(struct pt_regs *regs)
1795 {
1796         unsigned long ip;
1797
1798         if (perf_guest_cbs && perf_guest_cbs->is_in_guest())
1799                 ip = perf_guest_cbs->get_guest_ip();
1800         else
1801                 ip = instruction_pointer(regs);
1802
1803         return ip;
1804 }
1805
1806 unsigned long perf_misc_flags(struct pt_regs *regs)
1807 {
1808         int misc = 0;
1809
1810         if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
1811                 if (perf_guest_cbs->is_user_mode())
1812                         misc |= PERF_RECORD_MISC_GUEST_USER;
1813                 else
1814                         misc |= PERF_RECORD_MISC_GUEST_KERNEL;
1815         } else {
1816                 if (user_mode(regs))
1817                         misc |= PERF_RECORD_MISC_USER;
1818                 else
1819                         misc |= PERF_RECORD_MISC_KERNEL;
1820         }
1821
1822         if (regs->flags & PERF_EFLAGS_EXACT)
1823                 misc |= PERF_RECORD_MISC_EXACT_IP;
1824
1825         return misc;
1826 }