arch/x86/kernel/cpu/perf_event_intel_ds.c

   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
  15 struct pebs_record_32 {
  16         u32 flags, ip;
  17         u32 ax, bc, cx, dx;
  18         u32 si, di, bp, sp;
  19 };
  20
  21  */
  22
  23 struct 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
  31 struct 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  */
  45 struct 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
  57 static 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
  69 static 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
  77 static 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
 104 static 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
 115 static 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
 142 static 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
 153 static 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
 167 static 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
 178 static 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
 197 static 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
 263 static struct event_constraint bts_constraint =
 264         EVENT_CONSTRAINT(0, 1ULL << X86_PMC_IDX_FIXED_BTS, 0);
 265
 266 static 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
 285 static 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
 302 static 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), 1, 1))
 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  */
 364 static 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
 373 static 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
 380 static 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
 395 static 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
 410 static 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
 431 static struct event_constraint *
 432 intel_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
 449 static 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
 463 static 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
 478 static 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
 486 static 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
 496 static 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
 505 static 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         int is_64bit = 0;
 512
 513         /*
 514          * We don't need to fixup if the PEBS assist is fault like
 515          */
 516         if (!x86_pmu.intel_cap.pebs_trap)
 517                 return 1;
 518
 519         /*
 520          * No LBR entry, no basic block, no rewinding
 521          */
 522         if (!cpuc->lbr_stack.nr || !from || !to)
 523                 return 0;
 524
 525         /*
 526          * Basic blocks should never cross user/kernel boundaries
 527          */
 528         if (kernel_ip(ip) != kernel_ip(to))
 529                 return 0;
 530
 531         /*
 532          * unsigned math, either ip is before the start (impossible) or
 533          * the basic block is larger than 1 page (sanity)
 534          */
 535         if ((ip - to) > PAGE_SIZE)
 536                 return 0;
 537
 538         /*
 539          * We sampled a branch insn, rewind using the LBR stack
 540          */
 541         if (ip == to) {
 542                 regs->ip = from;
 543                 return 1;
 544         }
 545
 546         do {
 547                 struct insn insn;
 548                 u8 buf[MAX_INSN_SIZE];
 549                 void *kaddr;
 550
 551                 old_to = to;
 552                 if (!kernel_ip(ip)) {
 553                         int bytes, size = MAX_INSN_SIZE;
 554
 555                         bytes = copy_from_user_nmi(buf, (void __user *)to, size);
 556                         if (bytes != size)
 557                                 return 0;
 558
 559                         kaddr = buf;
 560                 } else
 561                         kaddr = (void *)to;
 562
 563 #ifdef CONFIG_X86_64
 564                 is_64bit = kernel_ip(to) || !test_thread_flag(TIF_IA32);
 565 #endif
 566                 insn_init(&insn, kaddr, is_64bit);
 567                 insn_get_length(&insn);
 568                 to += insn.length;
 569         } while (to < ip);
 570
 571         if (to == ip) {
 572                 regs->ip = old_to;
 573                 return 1;
 574         }
 575
 576         /*
 577          * Even though we decoded the basic block, the instruction stream
 578          * never matched the given IP, either the TO or the IP got corrupted.
 579          */
 580         return 0;
 581 }
 582
 583 static int intel_pmu_save_and_restart(struct perf_event *event);
 584
 585 static void __intel_pmu_pebs_event(struct perf_event *event,
 586                                    struct pt_regs *iregs, void *__pebs)
 587 {
 588         /*
 589          * We cast to pebs_record_core since that is a subset of
 590          * both formats and we don't use the other fields in this
 591          * routine.
 592          */
 593         struct pebs_record_core *pebs = __pebs;
 594         struct perf_sample_data data;
 595         struct pt_regs regs;
 596
 597         if (!intel_pmu_save_and_restart(event))
 598                 return;
 599
 600         perf_sample_data_init(&data, 0);
 601         data.period = event->hw.last_period;
 602
 603         /*
 604          * We use the interrupt regs as a base because the PEBS record
 605          * does not contain a full regs set, specifically it seems to
 606          * lack segment descriptors, which get used by things like
 607          * user_mode().
 608          *
 609          * In the simple case fix up only the IP and BP,SP regs, for
 610          * PERF_SAMPLE_IP and PERF_SAMPLE_CALLCHAIN to function properly.
 611          * A possible PERF_SAMPLE_REGS will have to transfer all regs.
 612          */
 613         regs = *iregs;
 614         regs.ip = pebs->ip;
 615         regs.bp = pebs->bp;
 616         regs.sp = pebs->sp;
 617
 618         if (event->attr.precise_ip > 1 && intel_pmu_pebs_fixup_ip(&regs))
 619                 regs.flags |= PERF_EFLAGS_EXACT;
 620         else
 621                 regs.flags &= ~PERF_EFLAGS_EXACT;
 622
 623         if (perf_event_overflow(event, 1, &data, &regs))
 624                 x86_pmu_stop(event, 0);
 625 }
 626
 627 static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
 628 {
 629         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 630         struct debug_store *ds = cpuc->ds;
 631         struct perf_event *event = cpuc->events[0]; /* PMC0 only */
 632         struct pebs_record_core *at, *top;
 633         int n;
 634
 635         if (!x86_pmu.pebs_active)
 636                 return;
 637
 638         at  = (struct pebs_record_core *)(unsigned long)ds->pebs_buffer_base;
 639         top = (struct pebs_record_core *)(unsigned long)ds->pebs_index;
 640
 641         /*
 642          * Whatever else happens, drain the thing
 643          */
 644         ds->pebs_index = ds->pebs_buffer_base;
 645
 646         if (!test_bit(0, cpuc->active_mask))
 647                 return;
 648
 649         WARN_ON_ONCE(!event);
 650
 651         if (!event->attr.precise_ip)
 652                 return;
 653
 654         n = top - at;
 655         if (n <= 0)
 656                 return;
 657
 658         /*
 659          * Should not happen, we program the threshold at 1 and do not
 660          * set a reset value.
 661          */
 662         WARN_ON_ONCE(n > 1);
 663         at += n - 1;
 664
 665         __intel_pmu_pebs_event(event, iregs, at);
 666 }
 667
 668 static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 669 {
 670         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 671         struct debug_store *ds = cpuc->ds;
 672         struct pebs_record_nhm *at, *top;
 673         struct perf_event *event = NULL;
 674         u64 status = 0;
 675         int bit, n;
 676
 677         if (!x86_pmu.pebs_active)
 678                 return;
 679
 680         at  = (struct pebs_record_nhm *)(unsigned long)ds->pebs_buffer_base;
 681         top = (struct pebs_record_nhm *)(unsigned long)ds->pebs_index;
 682
 683         ds->pebs_index = ds->pebs_buffer_base;
 684
 685         n = top - at;
 686         if (n <= 0)
 687                 return;
 688
 689         /*
 690          * Should not happen, we program the threshold at 1 and do not
 691          * set a reset value.
 692          */
 693         WARN_ON_ONCE(n > MAX_PEBS_EVENTS);
 694
 695         for ( ; at < top; at++) {
 696                 for_each_set_bit(bit, (unsigned long *)&at->status, MAX_PEBS_EVENTS) {
 697                         event = cpuc->events[bit];
 698                         if (!test_bit(bit, cpuc->active_mask))
 699                                 continue;
 700
 701                         WARN_ON_ONCE(!event);
 702
 703                         if (!event->attr.precise_ip)
 704                                 continue;
 705
 706                         if (__test_and_set_bit(bit, (unsigned long *)&status))
 707                                 continue;
 708
 709                         break;
 710                 }
 711
 712                 if (!event || bit >= MAX_PEBS_EVENTS)
 713                         continue;
 714
 715                 __intel_pmu_pebs_event(event, iregs, at);
 716         }
 717 }
 718
 719 /*
 720  * BTS, PEBS probe and setup
 721  */
 722
 723 static void intel_ds_init(void)
 724 {
 725         /*
 726          * No support for 32bit formats
 727          */
 728         if (!boot_cpu_has(X86_FEATURE_DTES64))
 729                 return;
 730
 731         x86_pmu.bts  = boot_cpu_has(X86_FEATURE_BTS);
 732         x86_pmu.pebs = boot_cpu_has(X86_FEATURE_PEBS);
 733         if (x86_pmu.pebs) {
 734                 char pebs_type = x86_pmu.intel_cap.pebs_trap ?  '+' : '-';
 735                 int format = x86_pmu.intel_cap.pebs_format;
 736
 737                 switch (format) {
 738                 case 0:
 739                         printk(KERN_CONT "PEBS fmt0%c, ", pebs_type);
 740                         x86_pmu.pebs_record_size = sizeof(struct pebs_record_core);
 741                         x86_pmu.drain_pebs = intel_pmu_drain_pebs_core;
 742                         break;
 743
 744                 case 1:
 745                         printk(KERN_CONT "PEBS fmt1%c, ", pebs_type);
 746                         x86_pmu.pebs_record_size = sizeof(struct pebs_record_nhm);
 747                         x86_pmu.drain_pebs = intel_pmu_drain_pebs_nhm;
 748                         break;
 749
 750                 default:
 751                         printk(KERN_CONT "no PEBS fmt%d%c, ", format, pebs_type);
 752                         x86_pmu.pebs = 0;
 753                 }
 754         }
 755 }
 756
 757 #else /* CONFIG_CPU_SUP_INTEL */
 758
 759 static void reserve_ds_buffers(void)
 760 {
 761 }
 762
 763 static void release_ds_buffers(void)
 764 {
 765 }
 766
 767 #endif /* CONFIG_CPU_SUP_INTEL */