arch/x86/oprofile/nmi_int.c

   1 /**
   2  * @file nmi_int.c
   3  *
   4  * @remark Copyright 2002-2009 OProfile authors
   5  * @remark Read the file COPYING
   6  *
   7  * @author John Levon <levon@movementarian.org>
   8  * @author Robert Richter <robert.richter@amd.com>
   9  * @author Barry Kasindorf <barry.kasindorf@amd.com>
  10  * @author Jason Yeh <jason.yeh@amd.com>
  11  * @author Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
  12  */
  13
  14 #include <linux/init.h>
  15 #include <linux/notifier.h>
  16 #include <linux/smp.h>
  17 #include <linux/oprofile.h>
  18 #include <linux/sysdev.h>
  19 #include <linux/slab.h>
  20 #include <linux/moduleparam.h>
  21 #include <linux/kdebug.h>
  22 #include <linux/cpu.h>
  23 #include <asm/nmi.h>
  24 #include <asm/msr.h>
  25 #include <asm/apic.h>
  26
  27 #include "op_counter.h"
  28 #include "op_x86_model.h"
  29
  30 static struct op_x86_model_spec *model;
  31 static DEFINE_PER_CPU(struct op_msrs, cpu_msrs);
  32 static DEFINE_PER_CPU(unsigned long, saved_lvtpc);
  33
  34 /* 0 == registered but off, 1 == registered and on */
  35 static int nmi_enabled = 0;
  36
  37 struct op_counter_config counter_config[OP_MAX_COUNTER];
  38
  39 /* common functions */
  40
  41 u64 op_x86_get_ctrl(struct op_x86_model_spec const *model,
  42                     struct op_counter_config *counter_config)
  43 {
  44         u64 val = 0;
  45         u16 event = (u16)counter_config->event;
  46
  47         val |= ARCH_PERFMON_EVENTSEL_INT;
  48         val |= counter_config->user ? ARCH_PERFMON_EVENTSEL_USR : 0;
  49         val |= counter_config->kernel ? ARCH_PERFMON_EVENTSEL_OS : 0;
  50         val |= (counter_config->unit_mask & 0xFF) << 8;
  51         event &= model->event_mask ? model->event_mask : 0xFF;
  52         val |= event & 0xFF;
  53         val |= (event & 0x0F00) << 24;
  54
  55         return val;
  56 }
  57
  58
  59 static int profile_exceptions_notify(struct notifier_block *self,
  60                                      unsigned long val, void *data)
  61 {
  62         struct die_args *args = (struct die_args *)data;
  63         int ret = NOTIFY_DONE;
  64         int cpu = smp_processor_id();
  65
  66         switch (val) {
  67         case DIE_NMI:
  68         case DIE_NMI_IPI:
  69                 model->check_ctrs(args->regs, &per_cpu(cpu_msrs, cpu));
  70                 ret = NOTIFY_STOP;
  71                 break;
  72         default:
  73                 break;
  74         }
  75         return ret;
  76 }
  77
  78 static void nmi_cpu_save_registers(struct op_msrs *msrs)
  79 {
  80         struct op_msr *counters = msrs->counters;
  81         struct op_msr *controls = msrs->controls;
  82         unsigned int i;
  83
  84         for (i = 0; i < model->num_counters; ++i) {
  85                 if (counters[i].addr)
  86                         rdmsrl(counters[i].addr, counters[i].saved);
  87         }
  88
  89         for (i = 0; i < model->num_controls; ++i) {
  90                 if (controls[i].addr)
  91                         rdmsrl(controls[i].addr, controls[i].saved);
  92         }
  93 }
  94
  95 static void nmi_cpu_start(void *dummy)
  96 {
  97         struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
  98         model->start(msrs);
  99 }
 100
 101 static int nmi_start(void)
 102 {
 103         on_each_cpu(nmi_cpu_start, NULL, 1);
 104         return 0;
 105 }
 106
 107 static void nmi_cpu_stop(void *dummy)
 108 {
 109         struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
 110         model->stop(msrs);
 111 }
 112
 113 static void nmi_stop(void)
 114 {
 115         on_each_cpu(nmi_cpu_stop, NULL, 1);
 116 }
 117
 118 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
 119
 120 static DEFINE_PER_CPU(int, switch_index);
 121
 122 static inline int has_mux(void)
 123 {
 124         return !!model->switch_ctrl;
 125 }
 126
 127 inline int op_x86_phys_to_virt(int phys)
 128 {
 129         return __get_cpu_var(switch_index) + phys;
 130 }
 131
 132 inline int op_x86_virt_to_phys(int virt)
 133 {
 134         return virt % model->num_counters;
 135 }
 136
 137 static void nmi_shutdown_mux(void)
 138 {
 139         int i;
 140
 141         if (!has_mux())
 142                 return;
 143
 144         for_each_possible_cpu(i) {
 145                 kfree(per_cpu(cpu_msrs, i).multiplex);
 146                 per_cpu(cpu_msrs, i).multiplex = NULL;
 147                 per_cpu(switch_index, i) = 0;
 148         }
 149 }
 150
 151 static int nmi_setup_mux(void)
 152 {
 153         size_t multiplex_size =
 154                 sizeof(struct op_msr) * model->num_virt_counters;
 155         int i;
 156
 157         if (!has_mux())
 158                 return 1;
 159
 160         for_each_possible_cpu(i) {
 161                 per_cpu(cpu_msrs, i).multiplex =
 162                         kmalloc(multiplex_size, GFP_KERNEL);
 163                 if (!per_cpu(cpu_msrs, i).multiplex)
 164                         return 0;
 165         }
 166
 167         return 1;
 168 }
 169
 170 static void nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs)
 171 {
 172         int i;
 173         struct op_msr *multiplex = msrs->multiplex;
 174
 175         if (!has_mux())
 176                 return;
 177
 178         for (i = 0; i < model->num_virt_counters; ++i) {
 179                 if (counter_config[i].enabled) {
 180                         multiplex[i].saved = -(u64)counter_config[i].count;
 181                 } else {
 182                         multiplex[i].addr  = 0;
 183                         multiplex[i].saved = 0;
 184                 }
 185         }
 186
 187         per_cpu(switch_index, cpu) = 0;
 188 }
 189
 190 static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs)
 191 {
 192         struct op_msr *multiplex = msrs->multiplex;
 193         int i;
 194
 195         for (i = 0; i < model->num_counters; ++i) {
 196                 int virt = op_x86_phys_to_virt(i);
 197                 if (multiplex[virt].addr)
 198                         rdmsrl(multiplex[virt].addr, multiplex[virt].saved);
 199         }
 200 }
 201
 202 static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs)
 203 {
 204         struct op_msr *multiplex = msrs->multiplex;
 205         int i;
 206
 207         for (i = 0; i < model->num_counters; ++i) {
 208                 int virt = op_x86_phys_to_virt(i);
 209                 if (multiplex[virt].addr)
 210                         wrmsrl(multiplex[virt].addr, multiplex[virt].saved);
 211         }
 212 }
 213
 214 static void nmi_cpu_switch(void *dummy)
 215 {
 216         int cpu = smp_processor_id();
 217         int si = per_cpu(switch_index, cpu);
 218         struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
 219
 220         nmi_cpu_stop(NULL);
 221         nmi_cpu_save_mpx_registers(msrs);
 222
 223         /* move to next set */
 224         si += model->num_counters;
 225         if ((si > model->num_virt_counters) || (counter_config[si].count == 0))
 226                 per_cpu(switch_index, cpu) = 0;
 227         else
 228                 per_cpu(switch_index, cpu) = si;
 229
 230         model->switch_ctrl(model, msrs);
 231         nmi_cpu_restore_mpx_registers(msrs);
 232
 233         nmi_cpu_start(NULL);
 234 }
 235
 236
 237 /*
 238  * Quick check to see if multiplexing is necessary.
 239  * The check should be sufficient since counters are used
 240  * in ordre.
 241  */
 242 static int nmi_multiplex_on(void)
 243 {
 244         return counter_config[model->num_counters].count ? 0 : -EINVAL;
 245 }
 246
 247 static int nmi_switch_event(void)
 248 {
 249         if (!has_mux())
 250                 return -ENOSYS;         /* not implemented */
 251         if (nmi_multiplex_on() < 0)
 252                 return -EINVAL;         /* not necessary */
 253
 254         on_each_cpu(nmi_cpu_switch, NULL, 1);
 255
 256         return 0;
 257 }
 258
 259 static inline void mux_init(struct oprofile_operations *ops)
 260 {
 261         if (has_mux())
 262                 ops->switch_events = nmi_switch_event;
 263 }
 264
 265 static void mux_clone(int cpu)
 266 {
 267         if (!has_mux())
 268                 return;
 269
 270         memcpy(per_cpu(cpu_msrs, cpu).multiplex,
 271                per_cpu(cpu_msrs, 0).multiplex,
 272                sizeof(struct op_msr) * model->num_virt_counters);
 273 }
 274
 275 #else
 276
 277 inline int op_x86_phys_to_virt(int phys) { return phys; }
 278 inline int op_x86_virt_to_phys(int virt) { return virt; }
 279 static inline void nmi_shutdown_mux(void) { }
 280 static inline int nmi_setup_mux(void) { return 1; }
 281 static inline void
 282 nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs) { }
 283 static inline void mux_init(struct oprofile_operations *ops) { }
 284 static void mux_clone(int cpu) { }
 285
 286 #endif
 287
 288 static void free_msrs(void)
 289 {
 290         int i;
 291         for_each_possible_cpu(i) {
 292                 kfree(per_cpu(cpu_msrs, i).counters);
 293                 per_cpu(cpu_msrs, i).counters = NULL;
 294                 kfree(per_cpu(cpu_msrs, i).controls);
 295                 per_cpu(cpu_msrs, i).controls = NULL;
 296         }
 297 }
 298
 299 static int allocate_msrs(void)
 300 {
 301         size_t controls_size = sizeof(struct op_msr) * model->num_controls;
 302         size_t counters_size = sizeof(struct op_msr) * model->num_counters;
 303
 304         int i;
 305         for_each_possible_cpu(i) {
 306                 per_cpu(cpu_msrs, i).counters = kmalloc(counters_size,
 307                                                         GFP_KERNEL);
 308                 if (!per_cpu(cpu_msrs, i).counters)
 309                         return 0;
 310                 per_cpu(cpu_msrs, i).controls = kmalloc(controls_size,
 311                                                         GFP_KERNEL);
 312                 if (!per_cpu(cpu_msrs, i).controls)
 313                         return 0;
 314         }
 315
 316         return 1;
 317 }
 318
 319 static void nmi_cpu_setup(void *dummy)
 320 {
 321         int cpu = smp_processor_id();
 322         struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
 323         nmi_cpu_save_registers(msrs);
 324         spin_lock(&oprofilefs_lock);
 325         model->setup_ctrs(model, msrs);
 326         nmi_cpu_setup_mux(cpu, msrs);
 327         spin_unlock(&oprofilefs_lock);
 328         per_cpu(saved_lvtpc, cpu) = apic_read(APIC_LVTPC);
 329         apic_write(APIC_LVTPC, APIC_DM_NMI);
 330 }
 331
 332 static struct notifier_block profile_exceptions_nb = {
 333         .notifier_call = profile_exceptions_notify,
 334         .next = NULL,
 335         .priority = 2
 336 };
 337
 338 static int nmi_setup(void)
 339 {
 340         int err = 0;
 341         int cpu;
 342
 343         if (!allocate_msrs())
 344                 err = -ENOMEM;
 345         else if (!nmi_setup_mux())
 346                 err = -ENOMEM;
 347         else
 348                 err = register_die_notifier(&profile_exceptions_nb);
 349
 350         if (err) {
 351                 free_msrs();
 352                 nmi_shutdown_mux();
 353                 return err;
 354         }
 355
 356         /* We need to serialize save and setup for HT because the subset
 357          * of msrs are distinct for save and setup operations
 358          */
 359
 360         /* Assume saved/restored counters are the same on all CPUs */
 361         model->fill_in_addresses(&per_cpu(cpu_msrs, 0));
 362         for_each_possible_cpu(cpu) {
 363                 if (!cpu)
 364                         continue;
 365
 366                 memcpy(per_cpu(cpu_msrs, cpu).counters,
 367                        per_cpu(cpu_msrs, 0).counters,
 368                        sizeof(struct op_msr) * model->num_counters);
 369
 370                 memcpy(per_cpu(cpu_msrs, cpu).controls,
 371                        per_cpu(cpu_msrs, 0).controls,
 372                        sizeof(struct op_msr) * model->num_controls);
 373
 374                 mux_clone(cpu);
 375         }
 376         on_each_cpu(nmi_cpu_setup, NULL, 1);
 377         nmi_enabled = 1;
 378         return 0;
 379 }
 380
 381 static void nmi_cpu_restore_registers(struct op_msrs *msrs)
 382 {
 383         struct op_msr *counters = msrs->counters;
 384         struct op_msr *controls = msrs->controls;
 385         unsigned int i;
 386
 387         for (i = 0; i < model->num_controls; ++i) {
 388                 if (controls[i].addr)
 389                         wrmsrl(controls[i].addr, controls[i].saved);
 390         }
 391
 392         for (i = 0; i < model->num_counters; ++i) {
 393                 if (counters[i].addr)
 394                         wrmsrl(counters[i].addr, counters[i].saved);
 395         }
 396 }
 397
 398 static void nmi_cpu_shutdown(void *dummy)
 399 {
 400         unsigned int v;
 401         int cpu = smp_processor_id();
 402         struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
 403
 404         /* restoring APIC_LVTPC can trigger an apic error because the delivery
 405          * mode and vector nr combination can be illegal. That's by design: on
 406          * power on apic lvt contain a zero vector nr which are legal only for
 407          * NMI delivery mode. So inhibit apic err before restoring lvtpc
 408          */
 409         v = apic_read(APIC_LVTERR);
 410         apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
 411         apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu));
 412         apic_write(APIC_LVTERR, v);
 413         nmi_cpu_restore_registers(msrs);
 414 }
 415
 416 static void nmi_shutdown(void)
 417 {
 418         struct op_msrs *msrs;
 419
 420         nmi_enabled = 0;
 421         on_each_cpu(nmi_cpu_shutdown, NULL, 1);
 422         unregister_die_notifier(&profile_exceptions_nb);
 423         nmi_shutdown_mux();
 424         msrs = &get_cpu_var(cpu_msrs);
 425         model->shutdown(msrs);
 426         free_msrs();
 427         put_cpu_var(cpu_msrs);
 428 }
 429
 430 static int nmi_create_files(struct super_block *sb, struct dentry *root)
 431 {
 432         unsigned int i;
 433
 434         for (i = 0; i < model->num_virt_counters; ++i) {
 435                 struct dentry *dir;
 436                 char buf[4];
 437
 438 #ifndef CONFIG_OPROFILE_EVENT_MULTIPLEX
 439                 /* quick little hack to _not_ expose a counter if it is not
 440                  * available for use.  This should protect userspace app.
 441                  * NOTE:  assumes 1:1 mapping here (that counters are organized
 442                  *        sequentially in their struct assignment).
 443                  */
 444                 if (unlikely(!avail_to_resrv_perfctr_nmi_bit(i)))
 445                         continue;
 446 #endif /* CONFIG_OPROFILE_EVENT_MULTIPLEX */
 447
 448                 snprintf(buf,  sizeof(buf), "%d", i);
 449                 dir = oprofilefs_mkdir(sb, root, buf);
 450                 oprofilefs_create_ulong(sb, dir, "enabled", &counter_config[i].enabled);
 451                 oprofilefs_create_ulong(sb, dir, "event", &counter_config[i].event);
 452                 oprofilefs_create_ulong(sb, dir, "count", &counter_config[i].count);
 453                 oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask);
 454                 oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel);
 455                 oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user);
 456         }
 457
 458         return 0;
 459 }
 460
 461 #ifdef CONFIG_SMP
 462 static int oprofile_cpu_notifier(struct notifier_block *b, unsigned long action,
 463                                  void *data)
 464 {
 465         int cpu = (unsigned long)data;
 466         switch (action) {
 467         case CPU_DOWN_FAILED:
 468         case CPU_ONLINE:
 469                 smp_call_function_single(cpu, nmi_cpu_start, NULL, 0);
 470                 break;
 471         case CPU_DOWN_PREPARE:
 472                 smp_call_function_single(cpu, nmi_cpu_stop, NULL, 1);
 473                 break;
 474         }
 475         return NOTIFY_DONE;
 476 }
 477
 478 static struct notifier_block oprofile_cpu_nb = {
 479         .notifier_call = oprofile_cpu_notifier
 480 };
 481 #endif
 482
 483 #ifdef CONFIG_PM
 484
 485 static int nmi_suspend(struct sys_device *dev, pm_message_t state)
 486 {
 487         /* Only one CPU left, just stop that one */
 488         if (nmi_enabled == 1)
 489                 nmi_cpu_stop(NULL);
 490         return 0;
 491 }
 492
 493 static int nmi_resume(struct sys_device *dev)
 494 {
 495         if (nmi_enabled == 1)
 496                 nmi_cpu_start(NULL);
 497         return 0;
 498 }
 499
 500 static struct sysdev_class oprofile_sysclass = {
 501         .name           = "oprofile",
 502         .resume         = nmi_resume,
 503         .suspend        = nmi_suspend,
 504 };
 505
 506 static struct sys_device device_oprofile = {
 507         .id     = 0,
 508         .cls    = &oprofile_sysclass,
 509 };
 510
 511 static int __init init_sysfs(void)
 512 {
 513         int error;
 514
 515         error = sysdev_class_register(&oprofile_sysclass);
 516         if (!error)
 517                 error = sysdev_register(&device_oprofile);
 518         return error;
 519 }
 520
 521 static void exit_sysfs(void)
 522 {
 523         sysdev_unregister(&device_oprofile);
 524         sysdev_class_unregister(&oprofile_sysclass);
 525 }
 526
 527 #else
 528 #define init_sysfs() do { } while (0)
 529 #define exit_sysfs() do { } while (0)
 530 #endif /* CONFIG_PM */
 531
 532 static int __init p4_init(char **cpu_type)
 533 {
 534         __u8 cpu_model = boot_cpu_data.x86_model;
 535
 536         if (cpu_model > 6 || cpu_model == 5)
 537                 return 0;
 538
 539 #ifndef CONFIG_SMP
 540         *cpu_type = "i386/p4";
 541         model = &op_p4_spec;
 542         return 1;
 543 #else
 544         switch (smp_num_siblings) {
 545         case 1:
 546                 *cpu_type = "i386/p4";
 547                 model = &op_p4_spec;
 548                 return 1;
 549
 550         case 2:
 551                 *cpu_type = "i386/p4-ht";
 552                 model = &op_p4_ht2_spec;
 553                 return 1;
 554         }
 555 #endif
 556
 557         printk(KERN_INFO "oprofile: P4 HyperThreading detected with > 2 threads\n");
 558         printk(KERN_INFO "oprofile: Reverting to timer mode.\n");
 559         return 0;
 560 }
 561
 562 static int force_arch_perfmon;
 563 static int force_cpu_type(const char *str, struct kernel_param *kp)
 564 {
 565         if (!strcmp(str, "arch_perfmon")) {
 566                 force_arch_perfmon = 1;
 567                 printk(KERN_INFO "oprofile: forcing architectural perfmon\n");
 568         }
 569
 570         return 0;
 571 }
 572 module_param_call(cpu_type, force_cpu_type, NULL, NULL, 0);
 573
 574 static int __init ppro_init(char **cpu_type)
 575 {
 576         __u8 cpu_model = boot_cpu_data.x86_model;
 577         struct op_x86_model_spec *spec = &op_ppro_spec; /* default */
 578
 579         if (force_arch_perfmon && cpu_has_arch_perfmon)
 580                 return 0;
 581
 582         switch (cpu_model) {
 583         case 0 ... 2:
 584                 *cpu_type = "i386/ppro";
 585                 break;
 586         case 3 ... 5:
 587                 *cpu_type = "i386/pii";
 588                 break;
 589         case 6 ... 8:
 590         case 10 ... 11:
 591                 *cpu_type = "i386/piii";
 592                 break;
 593         case 9:
 594         case 13:
 595                 *cpu_type = "i386/p6_mobile";
 596                 break;
 597         case 14:
 598                 *cpu_type = "i386/core";
 599                 break;
 600         case 15: case 23:
 601                 *cpu_type = "i386/core_2";
 602                 break;
 603         case 26:
 604                 spec = &op_arch_perfmon_spec;
 605                 *cpu_type = "i386/core_i7";
 606                 break;
 607         case 28:
 608                 *cpu_type = "i386/atom";
 609                 break;
 610         default:
 611                 /* Unknown */
 612                 return 0;
 613         }
 614
 615         model = spec;
 616         return 1;
 617 }
 618
 619 /* in order to get sysfs right */
 620 static int using_nmi;
 621
 622 int __init op_nmi_init(struct oprofile_operations *ops)
 623 {
 624         __u8 vendor = boot_cpu_data.x86_vendor;
 625         __u8 family = boot_cpu_data.x86;
 626         char *cpu_type = NULL;
 627         int ret = 0;
 628
 629         if (!cpu_has_apic)
 630                 return -ENODEV;
 631
 632         switch (vendor) {
 633         case X86_VENDOR_AMD:
 634                 /* Needs to be at least an Athlon (or hammer in 32bit mode) */
 635
 636                 switch (family) {
 637                 case 6:
 638                         cpu_type = "i386/athlon";
 639                         break;
 640                 case 0xf:
 641                         /*
 642                          * Actually it could be i386/hammer too, but
 643                          * give user space an consistent name.
 644                          */
 645                         cpu_type = "x86-64/hammer";
 646                         break;
 647                 case 0x10:
 648                         cpu_type = "x86-64/family10";
 649                         break;
 650                 case 0x11:
 651                         cpu_type = "x86-64/family11h";
 652                         break;
 653                 default:
 654                         return -ENODEV;
 655                 }
 656                 model = &op_amd_spec;
 657                 break;
 658
 659         case X86_VENDOR_INTEL:
 660                 switch (family) {
 661                         /* Pentium IV */
 662                 case 0xf:
 663                         p4_init(&cpu_type);
 664                         break;
 665
 666                         /* A P6-class processor */
 667                 case 6:
 668                         ppro_init(&cpu_type);
 669                         break;
 670
 671                 default:
 672                         break;
 673                 }
 674
 675                 if (cpu_type)
 676                         break;
 677
 678                 if (!cpu_has_arch_perfmon)
 679                         return -ENODEV;
 680
 681                 /* use arch perfmon as fallback */
 682                 cpu_type = "i386/arch_perfmon";
 683                 model = &op_arch_perfmon_spec;
 684                 break;
 685
 686         default:
 687                 return -ENODEV;
 688         }
 689
 690 #ifdef CONFIG_SMP
 691         register_cpu_notifier(&oprofile_cpu_nb);
 692 #endif
 693         /* default values, can be overwritten by model */
 694         ops->create_files       = nmi_create_files;
 695         ops->setup              = nmi_setup;
 696         ops->shutdown           = nmi_shutdown;
 697         ops->start              = nmi_start;
 698         ops->stop               = nmi_stop;
 699         ops->cpu_type           = cpu_type;
 700
 701         if (model->init)
 702                 ret = model->init(ops);
 703         if (ret)
 704                 return ret;
 705
 706         if (!model->num_virt_counters)
 707                 model->num_virt_counters = model->num_counters;
 708
 709         mux_init(ops);
 710
 711         init_sysfs();
 712         using_nmi = 1;
 713         printk(KERN_INFO "oprofile: using NMI interrupt.\n");
 714         return 0;
 715 }
 716
 717 void op_nmi_exit(void)
 718 {
 719         if (using_nmi) {
 720                 exit_sysfs();
 721 #ifdef CONFIG_SMP
 722                 unregister_cpu_notifier(&oprofile_cpu_nb);
 723 #endif
 724         }
 725         if (model->exit)
 726                 model->exit();
 727 }