linux/arch/x86/kernel/cpu/perf_event_intel_ds.c
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   1#ifdef CONFIG_CPU_SUP_INTEL
   2
   3/* The maximal number of PEBS events: */
   4#define MAX_PEBS_EVENTS         4
   5
   6/* The size of a BTS record in bytes: */
   7#define BTS_RECORD_SIZE         24
   8
   9#define BTS_BUFFER_SIZE         (PAGE_SIZE << 4)
  10#define PEBS_BUFFER_SIZE        PAGE_SIZE
  11
  12/*
  13 * pebs_record_32 for p4 and core not supported
  14
  15struct pebs_record_32 {
  16        u32 flags, ip;
  17        u32 ax, bc, cx, dx;
  18        u32 si, di, bp, sp;
  19};
  20
  21 */
  22
  23struct pebs_record_core {
  24        u64 flags, ip;
  25        u64 ax, bx, cx, dx;
  26        u64 si, di, bp, sp;
  27        u64 r8,  r9,  r10, r11;
  28        u64 r12, r13, r14, r15;
  29};
  30
  31struct pebs_record_nhm {
  32        u64 flags, ip;
  33        u64 ax, bx, cx, dx;
  34        u64 si, di, bp, sp;
  35        u64 r8,  r9,  r10, r11;
  36        u64 r12, r13, r14, r15;
  37        u64 status, dla, dse, lat;
  38};
  39
  40/*
  41 * A debug store configuration.
  42 *
  43 * We only support architectures that use 64bit fields.
  44 */
  45struct debug_store {
  46        u64     bts_buffer_base;
  47        u64     bts_index;
  48        u64     bts_absolute_maximum;
  49        u64     bts_interrupt_threshold;
  50        u64     pebs_buffer_base;
  51        u64     pebs_index;
  52        u64     pebs_absolute_maximum;
  53        u64     pebs_interrupt_threshold;
  54        u64     pebs_event_reset[MAX_PEBS_EVENTS];
  55};
  56
  57static void init_debug_store_on_cpu(int cpu)
  58{
  59        struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
  60
  61        if (!ds)
  62                return;
  63
  64        wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA,
  65                     (u32)((u64)(unsigned long)ds),
  66                     (u32)((u64)(unsigned long)ds >> 32));
  67}
  68
  69static void fini_debug_store_on_cpu(int cpu)
  70{
  71        if (!per_cpu(cpu_hw_events, cpu).ds)
  72                return;
  73
  74        wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, 0, 0);
  75}
  76
  77static int alloc_pebs_buffer(int cpu)
  78{
  79        struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
  80        int node = cpu_to_node(cpu);
  81        int max, thresh = 1; /* always use a single PEBS record */
  82        void *buffer;
  83
  84        if (!x86_pmu.pebs)
  85                return 0;
  86
  87        buffer = kmalloc_node(PEBS_BUFFER_SIZE, GFP_KERNEL | __GFP_ZERO, node);
  88        if (unlikely(!buffer))
  89                return -ENOMEM;
  90
  91        max = PEBS_BUFFER_SIZE / x86_pmu.pebs_record_size;
  92
  93        ds->pebs_buffer_base = (u64)(unsigned long)buffer;
  94        ds->pebs_index = ds->pebs_buffer_base;
  95        ds->pebs_absolute_maximum = ds->pebs_buffer_base +
  96                max * x86_pmu.pebs_record_size;
  97
  98        ds->pebs_interrupt_threshold = ds->pebs_buffer_base +
  99                thresh * x86_pmu.pebs_record_size;
 100
 101        return 0;
 102}
 103
 104static void release_pebs_buffer(int cpu)
 105{
 106        struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
 107
 108        if (!ds || !x86_pmu.pebs)
 109                return;
 110
 111        kfree((void *)(unsigned long)ds->pebs_buffer_base);
 112        ds->pebs_buffer_base = 0;
 113}
 114
 115static int alloc_bts_buffer(int cpu)
 116{
 117        struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
 118        int node = cpu_to_node(cpu);
 119        int max, thresh;
 120        void *buffer;
 121
 122        if (!x86_pmu.bts)
 123                return 0;
 124
 125        buffer = kmalloc_node(BTS_BUFFER_SIZE, GFP_KERNEL | __GFP_ZERO, node);
 126        if (unlikely(!buffer))
 127                return -ENOMEM;
 128
 129        max = BTS_BUFFER_SIZE / BTS_RECORD_SIZE;
 130        thresh = max / 16;
 131
 132        ds->bts_buffer_base = (u64)(unsigned long)buffer;
 133        ds->bts_index = ds->bts_buffer_base;
 134        ds->bts_absolute_maximum = ds->bts_buffer_base +
 135                max * BTS_RECORD_SIZE;
 136        ds->bts_interrupt_threshold = ds->bts_absolute_maximum -
 137                thresh * BTS_RECORD_SIZE;
 138
 139        return 0;
 140}
 141
 142static void release_bts_buffer(int cpu)
 143{
 144        struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
 145
 146        if (!ds || !x86_pmu.bts)
 147                return;
 148
 149        kfree((void *)(unsigned long)ds->bts_buffer_base);
 150        ds->bts_buffer_base = 0;
 151}
 152
 153static int alloc_ds_buffer(int cpu)
 154{
 155        int node = cpu_to_node(cpu);
 156        struct debug_store *ds;
 157
 158        ds = kmalloc_node(sizeof(*ds), GFP_KERNEL | __GFP_ZERO, node);
 159        if (unlikely(!ds))
 160                return -ENOMEM;
 161
 162        per_cpu(cpu_hw_events, cpu).ds = ds;
 163
 164        return 0;
 165}
 166
 167static void release_ds_buffer(int cpu)
 168{
 169        struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
 170
 171        if (!ds)
 172                return;
 173
 174        per_cpu(cpu_hw_events, cpu).ds = NULL;
 175        kfree(ds);
 176}
 177
 178static void release_ds_buffers(void)
 179{
 180        int cpu;
 181
 182        if (!x86_pmu.bts && !x86_pmu.pebs)
 183                return;
 184
 185        get_online_cpus();
 186        for_each_online_cpu(cpu)
 187                fini_debug_store_on_cpu(cpu);
 188
 189        for_each_possible_cpu(cpu) {
 190                release_pebs_buffer(cpu);
 191                release_bts_buffer(cpu);
 192                release_ds_buffer(cpu);
 193        }
 194        put_online_cpus();
 195}
 196
 197static void reserve_ds_buffers(void)
 198{
 199        int bts_err = 0, pebs_err = 0;
 200        int cpu;
 201
 202        x86_pmu.bts_active = 0;
 203        x86_pmu.pebs_active = 0;
 204
 205        if (!x86_pmu.bts && !x86_pmu.pebs)
 206                return;
 207
 208        if (!x86_pmu.bts)
 209                bts_err = 1;
 210
 211        if (!x86_pmu.pebs)
 212                pebs_err = 1;
 213
 214        get_online_cpus();
 215
 216        for_each_possible_cpu(cpu) {
 217                if (alloc_ds_buffer(cpu)) {
 218                        bts_err = 1;
 219                        pebs_err = 1;
 220                }
 221
 222                if (!bts_err && alloc_bts_buffer(cpu))
 223                        bts_err = 1;
 224
 225                if (!pebs_err && alloc_pebs_buffer(cpu))
 226                        pebs_err = 1;
 227
 228                if (bts_err && pebs_err)
 229                        break;
 230        }
 231
 232        if (bts_err) {
 233                for_each_possible_cpu(cpu)
 234                        release_bts_buffer(cpu);
 235        }
 236
 237        if (pebs_err) {
 238                for_each_possible_cpu(cpu)
 239                        release_pebs_buffer(cpu);
 240        }
 241
 242        if (bts_err && pebs_err) {
 243                for_each_possible_cpu(cpu)
 244                        release_ds_buffer(cpu);
 245        } else {
 246                if (x86_pmu.bts && !bts_err)
 247                        x86_pmu.bts_active = 1;
 248
 249                if (x86_pmu.pebs && !pebs_err)
 250                        x86_pmu.pebs_active = 1;
 251
 252                for_each_online_cpu(cpu)
 253                        init_debug_store_on_cpu(cpu);
 254        }
 255
 256        put_online_cpus();
 257}
 258
 259/*
 260 * BTS
 261 */
 262
 263static struct event_constraint bts_constraint =
 264        EVENT_CONSTRAINT(0, 1ULL << X86_PMC_IDX_FIXED_BTS, 0);
 265
 266static void intel_pmu_enable_bts(u64 config)
 267{
 268        unsigned long debugctlmsr;
 269
 270        debugctlmsr = get_debugctlmsr();
 271
 272        debugctlmsr |= DEBUGCTLMSR_TR;
 273        debugctlmsr |= DEBUGCTLMSR_BTS;
 274        debugctlmsr |= DEBUGCTLMSR_BTINT;
 275
 276        if (!(config & ARCH_PERFMON_EVENTSEL_OS))
 277                debugctlmsr |= DEBUGCTLMSR_BTS_OFF_OS;
 278
 279        if (!(config & ARCH_PERFMON_EVENTSEL_USR))
 280                debugctlmsr |= DEBUGCTLMSR_BTS_OFF_USR;
 281
 282        update_debugctlmsr(debugctlmsr);
 283}
 284
 285static void intel_pmu_disable_bts(void)
 286{
 287        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 288        unsigned long debugctlmsr;
 289
 290        if (!cpuc->ds)
 291                return;
 292
 293        debugctlmsr = get_debugctlmsr();
 294
 295        debugctlmsr &=
 296                ~(DEBUGCTLMSR_TR | DEBUGCTLMSR_BTS | DEBUGCTLMSR_BTINT |
 297                  DEBUGCTLMSR_BTS_OFF_OS | DEBUGCTLMSR_BTS_OFF_USR);
 298
 299        update_debugctlmsr(debugctlmsr);
 300}
 301
 302static int intel_pmu_drain_bts_buffer(void)
 303{
 304        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 305        struct debug_store *ds = cpuc->ds;
 306        struct bts_record {
 307                u64     from;
 308                u64     to;
 309                u64     flags;
 310        };
 311        struct perf_event *event = cpuc->events[X86_PMC_IDX_FIXED_BTS];
 312        struct bts_record *at, *top;
 313        struct perf_output_handle handle;
 314        struct perf_event_header header;
 315        struct perf_sample_data data;
 316        struct pt_regs regs;
 317
 318        if (!event)
 319                return 0;
 320
 321        if (!x86_pmu.bts_active)
 322                return 0;
 323
 324        at  = (struct bts_record *)(unsigned long)ds->bts_buffer_base;
 325        top = (struct bts_record *)(unsigned long)ds->bts_index;
 326
 327        if (top <= at)
 328                return 0;
 329
 330        ds->bts_index = ds->bts_buffer_base;
 331
 332        perf_sample_data_init(&data, 0);
 333        data.period = event->hw.last_period;
 334        regs.ip     = 0;
 335
 336        /*
 337         * Prepare a generic sample, i.e. fill in the invariant fields.
 338         * We will overwrite the from and to address before we output
 339         * the sample.
 340         */
 341        perf_prepare_sample(&header, &data, event, &regs);
 342
 343        if (perf_output_begin(&handle, event, header.size * (top - at)))
 344                return 1;
 345
 346        for (; at < top; at++) {
 347                data.ip         = at->from;
 348                data.addr       = at->to;
 349
 350                perf_output_sample(&handle, &header, &data, event);
 351        }
 352
 353        perf_output_end(&handle);
 354
 355        /* There's new data available. */
 356        event->hw.interrupts++;
 357        event->pending_kill = POLL_IN;
 358        return 1;
 359}
 360
 361/*
 362 * PEBS
 363 */
 364static struct event_constraint intel_core2_pebs_event_constraints[] = {
 365        INTEL_UEVENT_CONSTRAINT(0x00c0, 0x1), /* INST_RETIRED.ANY */
 366        INTEL_UEVENT_CONSTRAINT(0xfec1, 0x1), /* X87_OPS_RETIRED.ANY */
 367        INTEL_UEVENT_CONSTRAINT(0x00c5, 0x1), /* BR_INST_RETIRED.MISPRED */
 368        INTEL_UEVENT_CONSTRAINT(0x1fc7, 0x1), /* SIMD_INST_RETURED.ANY */
 369        INTEL_EVENT_CONSTRAINT(0xcb, 0x1),    /* MEM_LOAD_RETIRED.* */
 370        EVENT_CONSTRAINT_END
 371};
 372
 373static struct event_constraint intel_atom_pebs_event_constraints[] = {
 374        INTEL_UEVENT_CONSTRAINT(0x00c0, 0x1), /* INST_RETIRED.ANY */
 375        INTEL_UEVENT_CONSTRAINT(0x00c5, 0x1), /* MISPREDICTED_BRANCH_RETIRED */
 376        INTEL_EVENT_CONSTRAINT(0xcb, 0x1),    /* MEM_LOAD_RETIRED.* */
 377        EVENT_CONSTRAINT_END
 378};
 379
 380static struct event_constraint intel_nehalem_pebs_event_constraints[] = {
 381        INTEL_EVENT_CONSTRAINT(0x0b, 0xf),    /* MEM_INST_RETIRED.* */
 382        INTEL_EVENT_CONSTRAINT(0x0f, 0xf),    /* MEM_UNCORE_RETIRED.* */
 383        INTEL_UEVENT_CONSTRAINT(0x010c, 0xf), /* MEM_STORE_RETIRED.DTLB_MISS */
 384        INTEL_EVENT_CONSTRAINT(0xc0, 0xf),    /* INST_RETIRED.ANY */
 385        INTEL_EVENT_CONSTRAINT(0xc2, 0xf),    /* UOPS_RETIRED.* */
 386        INTEL_EVENT_CONSTRAINT(0xc4, 0xf),    /* BR_INST_RETIRED.* */
 387        INTEL_UEVENT_CONSTRAINT(0x02c5, 0xf), /* BR_MISP_RETIRED.NEAR_CALL */
 388        INTEL_EVENT_CONSTRAINT(0xc7, 0xf),    /* SSEX_UOPS_RETIRED.* */
 389        INTEL_UEVENT_CONSTRAINT(0x20c8, 0xf), /* ITLB_MISS_RETIRED */
 390        INTEL_EVENT_CONSTRAINT(0xcb, 0xf),    /* MEM_LOAD_RETIRED.* */
 391        INTEL_EVENT_CONSTRAINT(0xf7, 0xf),    /* FP_ASSIST.* */
 392        EVENT_CONSTRAINT_END
 393};
 394
 395static struct event_constraint intel_westmere_pebs_event_constraints[] = {
 396        INTEL_EVENT_CONSTRAINT(0x0b, 0xf),    /* MEM_INST_RETIRED.* */
 397        INTEL_EVENT_CONSTRAINT(0x0f, 0xf),    /* MEM_UNCORE_RETIRED.* */
 398        INTEL_UEVENT_CONSTRAINT(0x010c, 0xf), /* MEM_STORE_RETIRED.DTLB_MISS */
 399        INTEL_EVENT_CONSTRAINT(0xc0, 0xf),    /* INSTR_RETIRED.* */
 400        INTEL_EVENT_CONSTRAINT(0xc2, 0xf),    /* UOPS_RETIRED.* */
 401        INTEL_EVENT_CONSTRAINT(0xc4, 0xf),    /* BR_INST_RETIRED.* */
 402        INTEL_EVENT_CONSTRAINT(0xc5, 0xf),    /* BR_MISP_RETIRED.* */
 403        INTEL_EVENT_CONSTRAINT(0xc7, 0xf),    /* SSEX_UOPS_RETIRED.* */
 404        INTEL_UEVENT_CONSTRAINT(0x20c8, 0xf), /* ITLB_MISS_RETIRED */
 405        INTEL_EVENT_CONSTRAINT(0xcb, 0xf),    /* MEM_LOAD_RETIRED.* */
 406        INTEL_EVENT_CONSTRAINT(0xf7, 0xf),    /* FP_ASSIST.* */
 407        EVENT_CONSTRAINT_END
 408};
 409
 410static struct event_constraint intel_snb_pebs_events[] = {
 411        INTEL_UEVENT_CONSTRAINT(0x01c0, 0x2), /* INST_RETIRED.PRECDIST */
 412        INTEL_UEVENT_CONSTRAINT(0x01c2, 0xf), /* UOPS_RETIRED.ALL */
 413        INTEL_UEVENT_CONSTRAINT(0x02c2, 0xf), /* UOPS_RETIRED.RETIRE_SLOTS */
 414        INTEL_EVENT_CONSTRAINT(0xc4, 0xf),    /* BR_INST_RETIRED.* */
 415        INTEL_EVENT_CONSTRAINT(0xc5, 0xf),    /* BR_MISP_RETIRED.* */
 416        INTEL_EVENT_CONSTRAINT(0xcd, 0x8),    /* MEM_TRANS_RETIRED.* */
 417        INTEL_UEVENT_CONSTRAINT(0x11d0, 0xf), /* MEM_UOP_RETIRED.STLB_MISS_LOADS */
 418        INTEL_UEVENT_CONSTRAINT(0x12d0, 0xf), /* MEM_UOP_RETIRED.STLB_MISS_STORES */
 419        INTEL_UEVENT_CONSTRAINT(0x21d0, 0xf), /* MEM_UOP_RETIRED.LOCK_LOADS */
 420        INTEL_UEVENT_CONSTRAINT(0x22d0, 0xf), /* MEM_UOP_RETIRED.LOCK_STORES */
 421        INTEL_UEVENT_CONSTRAINT(0x41d0, 0xf), /* MEM_UOP_RETIRED.SPLIT_LOADS */
 422        INTEL_UEVENT_CONSTRAINT(0x42d0, 0xf), /* MEM_UOP_RETIRED.SPLIT_STORES */
 423        INTEL_UEVENT_CONSTRAINT(0x81d0, 0xf), /* MEM_UOP_RETIRED.ANY_LOADS */
 424        INTEL_UEVENT_CONSTRAINT(0x82d0, 0xf), /* MEM_UOP_RETIRED.ANY_STORES */
 425        INTEL_EVENT_CONSTRAINT(0xd1, 0xf),    /* MEM_LOAD_UOPS_RETIRED.* */
 426        INTEL_EVENT_CONSTRAINT(0xd2, 0xf),    /* MEM_LOAD_UOPS_LLC_HIT_RETIRED.* */
 427        INTEL_UEVENT_CONSTRAINT(0x02d4, 0xf), /* MEM_LOAD_UOPS_MISC_RETIRED.LLC_MISS */
 428        EVENT_CONSTRAINT_END
 429};
 430
 431static struct event_constraint *
 432intel_pebs_constraints(struct perf_event *event)
 433{
 434        struct event_constraint *c;
 435
 436        if (!event->attr.precise_ip)
 437                return NULL;
 438
 439        if (x86_pmu.pebs_constraints) {
 440                for_each_event_constraint(c, x86_pmu.pebs_constraints) {
 441                        if ((event->hw.config & c->cmask) == c->code)
 442                                return c;
 443                }
 444        }
 445
 446        return &emptyconstraint;
 447}
 448
 449static void intel_pmu_pebs_enable(struct perf_event *event)
 450{
 451        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 452        struct hw_perf_event *hwc = &event->hw;
 453
 454        hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
 455
 456        cpuc->pebs_enabled |= 1ULL << hwc->idx;
 457        WARN_ON_ONCE(cpuc->enabled);
 458
 459        if (x86_pmu.intel_cap.pebs_trap && event->attr.precise_ip > 1)
 460                intel_pmu_lbr_enable(event);
 461}
 462
 463static void intel_pmu_pebs_disable(struct perf_event *event)
 464{
 465        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 466        struct hw_perf_event *hwc = &event->hw;
 467
 468        cpuc->pebs_enabled &= ~(1ULL << hwc->idx);
 469        if (cpuc->enabled)
 470                wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
 471
 472        hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
 473
 474        if (x86_pmu.intel_cap.pebs_trap && event->attr.precise_ip > 1)
 475                intel_pmu_lbr_disable(event);
 476}
 477
 478static void intel_pmu_pebs_enable_all(void)
 479{
 480        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 481
 482        if (cpuc->pebs_enabled)
 483                wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
 484}
 485
 486static void intel_pmu_pebs_disable_all(void)
 487{
 488        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 489
 490        if (cpuc->pebs_enabled)
 491                wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
 492}
 493
 494#include <asm/insn.h>
 495
 496static inline bool kernel_ip(unsigned long ip)
 497{
 498#ifdef CONFIG_X86_32
 499        return ip > PAGE_OFFSET;
 500#else
 501        return (long)ip < 0;
 502#endif
 503}
 504
 505static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
 506{
 507        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 508        unsigned long from = cpuc->lbr_entries[0].from;
 509        unsigned long old_to, to = cpuc->lbr_entries[0].to;
 510        unsigned long ip = regs->ip;
 511
 512        /*
 513         * We don't need to fixup if the PEBS assist is fault like
 514         */
 515        if (!x86_pmu.intel_cap.pebs_trap)
 516                return 1;
 517
 518        /*
 519         * No LBR entry, no basic block, no rewinding
 520         */
 521        if (!cpuc->lbr_stack.nr || !from || !to)
 522                return 0;
 523
 524        /*
 525         * Basic blocks should never cross user/kernel boundaries
 526         */
 527        if (kernel_ip(ip) != kernel_ip(to))
 528                return 0;
 529
 530        /*
 531         * unsigned math, either ip is before the start (impossible) or
 532         * the basic block is larger than 1 page (sanity)
 533         */
 534        if ((ip - to) > PAGE_SIZE)
 535                return 0;
 536
 537        /*
 538         * We sampled a branch insn, rewind using the LBR stack
 539         */
 540        if (ip == to) {
 541                regs->ip = from;
 542                return 1;
 543        }
 544
 545        do {
 546                struct insn insn;
 547                u8 buf[MAX_INSN_SIZE];
 548                void *kaddr;
 549
 550                old_to = to;
 551                if (!kernel_ip(ip)) {
 552                        int bytes, size = MAX_INSN_SIZE;
 553
 554                        bytes = copy_from_user_nmi(buf, (void __user *)to, size);
 555                        if (bytes != size)
 556                                return 0;
 557
 558                        kaddr = buf;
 559                } else
 560                        kaddr = (void *)to;
 561
 562                kernel_insn_init(&insn, kaddr);
 563                insn_get_length(&insn);
 564                to += insn.length;
 565        } while (to < ip);
 566
 567        if (to == ip) {
 568                regs->ip = old_to;
 569                return 1;
 570        }
 571
 572        /*
 573         * Even though we decoded the basic block, the instruction stream
 574         * never matched the given IP, either the TO or the IP got corrupted.
 575         */
 576        return 0;
 577}
 578
 579static int intel_pmu_save_and_restart(struct perf_event *event);
 580
 581static void __intel_pmu_pebs_event(struct perf_event *event,
 582                                   struct pt_regs *iregs, void *__pebs)
 583{
 584        /*
 585         * We cast to pebs_record_core since that is a subset of
 586         * both formats and we don't use the other fields in this
 587         * routine.
 588         */
 589        struct pebs_record_core *pebs = __pebs;
 590        struct perf_sample_data data;
 591        struct pt_regs regs;
 592
 593        if (!intel_pmu_save_and_restart(event))
 594                return;
 595
 596        perf_sample_data_init(&data, 0);
 597        data.period = event->hw.last_period;
 598
 599        /*
 600         * We use the interrupt regs as a base because the PEBS record
 601         * does not contain a full regs set, specifically it seems to
 602         * lack segment descriptors, which get used by things like
 603         * user_mode().
 604         *
 605         * In the simple case fix up only the IP and BP,SP regs, for
 606         * PERF_SAMPLE_IP and PERF_SAMPLE_CALLCHAIN to function properly.
 607         * A possible PERF_SAMPLE_REGS will have to transfer all regs.
 608         */
 609        regs = *iregs;
 610        regs.ip = pebs->ip;
 611        regs.bp = pebs->bp;
 612        regs.sp = pebs->sp;
 613
 614        if (event->attr.precise_ip > 1 && intel_pmu_pebs_fixup_ip(&regs))
 615                regs.flags |= PERF_EFLAGS_EXACT;
 616        else
 617                regs.flags &= ~PERF_EFLAGS_EXACT;
 618
 619        if (perf_event_overflow(event, &data, &regs))
 620                x86_pmu_stop(event, 0);
 621}
 622
 623static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
 624{
 625        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 626        struct debug_store *ds = cpuc->ds;
 627        struct perf_event *event = cpuc->events[0]; /* PMC0 only */
 628        struct pebs_record_core *at, *top;
 629        int n;
 630
 631        if (!x86_pmu.pebs_active)
 632                return;
 633
 634        at  = (struct pebs_record_core *)(unsigned long)ds->pebs_buffer_base;
 635        top = (struct pebs_record_core *)(unsigned long)ds->pebs_index;
 636
 637        /*
 638         * Whatever else happens, drain the thing
 639         */
 640        ds->pebs_index = ds->pebs_buffer_base;
 641
 642        if (!test_bit(0, cpuc->active_mask))
 643                return;
 644
 645        WARN_ON_ONCE(!event);
 646
 647        if (!event->attr.precise_ip)
 648                return;
 649
 650        n = top - at;
 651        if (n <= 0)
 652                return;
 653
 654        /*
 655         * Should not happen, we program the threshold at 1 and do not
 656         * set a reset value.
 657         */
 658        WARN_ON_ONCE(n > 1);
 659        at += n - 1;
 660
 661        __intel_pmu_pebs_event(event, iregs, at);
 662}
 663
 664static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 665{
 666        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 667        struct debug_store *ds = cpuc->ds;
 668        struct pebs_record_nhm *at, *top;
 669        struct perf_event *event = NULL;
 670        u64 status = 0;
 671        int bit, n;
 672
 673        if (!x86_pmu.pebs_active)
 674                return;
 675
 676        at  = (struct pebs_record_nhm *)(unsigned long)ds->pebs_buffer_base;
 677        top = (struct pebs_record_nhm *)(unsigned long)ds->pebs_index;
 678
 679        ds->pebs_index = ds->pebs_buffer_base;
 680
 681        n = top - at;
 682        if (n <= 0)
 683                return;
 684
 685        /*
 686         * Should not happen, we program the threshold at 1 and do not
 687         * set a reset value.
 688         */
 689        WARN_ON_ONCE(n > MAX_PEBS_EVENTS);
 690
 691        for ( ; at < top; at++) {
 692                for_each_set_bit(bit, (unsigned long *)&at->status, MAX_PEBS_EVENTS) {
 693                        event = cpuc->events[bit];
 694                        if (!test_bit(bit, cpuc->active_mask))
 695                                continue;
 696
 697                        WARN_ON_ONCE(!event);
 698
 699                        if (!event->attr.precise_ip)
 700                                continue;
 701
 702                        if (__test_and_set_bit(bit, (unsigned long *)&status))
 703                                continue;
 704
 705                        break;
 706                }
 707
 708                if (!event || bit >= MAX_PEBS_EVENTS)
 709                        continue;
 710
 711                __intel_pmu_pebs_event(event, iregs, at);
 712        }
 713}
 714
 715/*
 716 * BTS, PEBS probe and setup
 717 */
 718
 719static void intel_ds_init(void)
 720{
 721        /*
 722         * No support for 32bit formats
 723         */
 724        if (!boot_cpu_has(X86_FEATURE_DTES64))
 725                return;
 726
 727        x86_pmu.bts  = boot_cpu_has(X86_FEATURE_BTS);
 728        x86_pmu.pebs = boot_cpu_has(X86_FEATURE_PEBS);
 729        if (x86_pmu.pebs) {
 730                char pebs_type = x86_pmu.intel_cap.pebs_trap ?  '+' : '-';
 731                int format = x86_pmu.intel_cap.pebs_format;
 732
 733                switch (format) {
 734                case 0:
 735                        printk(KERN_CONT "PEBS fmt0%c, ", pebs_type);
 736                        x86_pmu.pebs_record_size = sizeof(struct pebs_record_core);
 737                        x86_pmu.drain_pebs = intel_pmu_drain_pebs_core;
 738                        break;
 739
 740                case 1:
 741                        printk(KERN_CONT "PEBS fmt1%c, ", pebs_type);
 742                        x86_pmu.pebs_record_size = sizeof(struct pebs_record_nhm);
 743                        x86_pmu.drain_pebs = intel_pmu_drain_pebs_nhm;
 744                        break;
 745
 746                default:
 747                        printk(KERN_CONT "no PEBS fmt%d%c, ", format, pebs_type);
 748                        x86_pmu.pebs = 0;
 749                }
 750        }
 751}
 752
 753#else /* CONFIG_CPU_SUP_INTEL */
 754
 755static void reserve_ds_buffers(void)
 756{
 757}
 758
 759static void release_ds_buffers(void)
 760{
 761}
 762
 763#endif /* CONFIG_CPU_SUP_INTEL */
 764