Merge tag 'afs-next-20171113' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowel...
[sfrench/cifs-2.6.git] / 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/syscore_ops.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 /* must be protected with get_online_cpus()/put_online_cpus(): */
35 static int nmi_enabled;
36 static int ctr_running;
37
38 struct op_counter_config counter_config[OP_MAX_COUNTER];
39
40 /* common functions */
41
42 u64 op_x86_get_ctrl(struct op_x86_model_spec const *model,
43                     struct op_counter_config *counter_config)
44 {
45         u64 val = 0;
46         u16 event = (u16)counter_config->event;
47
48         val |= ARCH_PERFMON_EVENTSEL_INT;
49         val |= counter_config->user ? ARCH_PERFMON_EVENTSEL_USR : 0;
50         val |= counter_config->kernel ? ARCH_PERFMON_EVENTSEL_OS : 0;
51         val |= (counter_config->unit_mask & 0xFF) << 8;
52         counter_config->extra &= (ARCH_PERFMON_EVENTSEL_INV |
53                                   ARCH_PERFMON_EVENTSEL_EDGE |
54                                   ARCH_PERFMON_EVENTSEL_CMASK);
55         val |= counter_config->extra;
56         event &= model->event_mask ? model->event_mask : 0xFF;
57         val |= event & 0xFF;
58         val |= (u64)(event & 0x0F00) << 24;
59
60         return val;
61 }
62
63
64 static int profile_exceptions_notify(unsigned int val, struct pt_regs *regs)
65 {
66         if (ctr_running)
67                 model->check_ctrs(regs, this_cpu_ptr(&cpu_msrs));
68         else if (!nmi_enabled)
69                 return NMI_DONE;
70         else
71                 model->stop(this_cpu_ptr(&cpu_msrs));
72         return NMI_HANDLED;
73 }
74
75 static void nmi_cpu_save_registers(struct op_msrs *msrs)
76 {
77         struct op_msr *counters = msrs->counters;
78         struct op_msr *controls = msrs->controls;
79         unsigned int i;
80
81         for (i = 0; i < model->num_counters; ++i) {
82                 if (counters[i].addr)
83                         rdmsrl(counters[i].addr, counters[i].saved);
84         }
85
86         for (i = 0; i < model->num_controls; ++i) {
87                 if (controls[i].addr)
88                         rdmsrl(controls[i].addr, controls[i].saved);
89         }
90 }
91
92 static void nmi_cpu_start(void *dummy)
93 {
94         struct op_msrs const *msrs = this_cpu_ptr(&cpu_msrs);
95         if (!msrs->controls)
96                 WARN_ON_ONCE(1);
97         else
98                 model->start(msrs);
99 }
100
101 static int nmi_start(void)
102 {
103         get_online_cpus();
104         ctr_running = 1;
105         /* make ctr_running visible to the nmi handler: */
106         smp_mb();
107         on_each_cpu(nmi_cpu_start, NULL, 1);
108         put_online_cpus();
109         return 0;
110 }
111
112 static void nmi_cpu_stop(void *dummy)
113 {
114         struct op_msrs const *msrs = this_cpu_ptr(&cpu_msrs);
115         if (!msrs->controls)
116                 WARN_ON_ONCE(1);
117         else
118                 model->stop(msrs);
119 }
120
121 static void nmi_stop(void)
122 {
123         get_online_cpus();
124         on_each_cpu(nmi_cpu_stop, NULL, 1);
125         ctr_running = 0;
126         put_online_cpus();
127 }
128
129 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
130
131 static DEFINE_PER_CPU(int, switch_index);
132
133 static inline int has_mux(void)
134 {
135         return !!model->switch_ctrl;
136 }
137
138 inline int op_x86_phys_to_virt(int phys)
139 {
140         return __this_cpu_read(switch_index) + phys;
141 }
142
143 inline int op_x86_virt_to_phys(int virt)
144 {
145         return virt % model->num_counters;
146 }
147
148 static void nmi_shutdown_mux(void)
149 {
150         int i;
151
152         if (!has_mux())
153                 return;
154
155         for_each_possible_cpu(i) {
156                 kfree(per_cpu(cpu_msrs, i).multiplex);
157                 per_cpu(cpu_msrs, i).multiplex = NULL;
158                 per_cpu(switch_index, i) = 0;
159         }
160 }
161
162 static int nmi_setup_mux(void)
163 {
164         size_t multiplex_size =
165                 sizeof(struct op_msr) * model->num_virt_counters;
166         int i;
167
168         if (!has_mux())
169                 return 1;
170
171         for_each_possible_cpu(i) {
172                 per_cpu(cpu_msrs, i).multiplex =
173                         kzalloc(multiplex_size, GFP_KERNEL);
174                 if (!per_cpu(cpu_msrs, i).multiplex)
175                         return 0;
176         }
177
178         return 1;
179 }
180
181 static void nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs)
182 {
183         int i;
184         struct op_msr *multiplex = msrs->multiplex;
185
186         if (!has_mux())
187                 return;
188
189         for (i = 0; i < model->num_virt_counters; ++i) {
190                 if (counter_config[i].enabled) {
191                         multiplex[i].saved = -(u64)counter_config[i].count;
192                 } else {
193                         multiplex[i].saved = 0;
194                 }
195         }
196
197         per_cpu(switch_index, cpu) = 0;
198 }
199
200 static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs)
201 {
202         struct op_msr *counters = msrs->counters;
203         struct op_msr *multiplex = msrs->multiplex;
204         int i;
205
206         for (i = 0; i < model->num_counters; ++i) {
207                 int virt = op_x86_phys_to_virt(i);
208                 if (counters[i].addr)
209                         rdmsrl(counters[i].addr, multiplex[virt].saved);
210         }
211 }
212
213 static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs)
214 {
215         struct op_msr *counters = msrs->counters;
216         struct op_msr *multiplex = msrs->multiplex;
217         int i;
218
219         for (i = 0; i < model->num_counters; ++i) {
220                 int virt = op_x86_phys_to_virt(i);
221                 if (counters[i].addr)
222                         wrmsrl(counters[i].addr, multiplex[virt].saved);
223         }
224 }
225
226 static void nmi_cpu_switch(void *dummy)
227 {
228         int cpu = smp_processor_id();
229         int si = per_cpu(switch_index, cpu);
230         struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
231
232         nmi_cpu_stop(NULL);
233         nmi_cpu_save_mpx_registers(msrs);
234
235         /* move to next set */
236         si += model->num_counters;
237         if ((si >= model->num_virt_counters) || (counter_config[si].count == 0))
238                 per_cpu(switch_index, cpu) = 0;
239         else
240                 per_cpu(switch_index, cpu) = si;
241
242         model->switch_ctrl(model, msrs);
243         nmi_cpu_restore_mpx_registers(msrs);
244
245         nmi_cpu_start(NULL);
246 }
247
248
249 /*
250  * Quick check to see if multiplexing is necessary.
251  * The check should be sufficient since counters are used
252  * in ordre.
253  */
254 static int nmi_multiplex_on(void)
255 {
256         return counter_config[model->num_counters].count ? 0 : -EINVAL;
257 }
258
259 static int nmi_switch_event(void)
260 {
261         if (!has_mux())
262                 return -ENOSYS;         /* not implemented */
263         if (nmi_multiplex_on() < 0)
264                 return -EINVAL;         /* not necessary */
265
266         get_online_cpus();
267         if (ctr_running)
268                 on_each_cpu(nmi_cpu_switch, NULL, 1);
269         put_online_cpus();
270
271         return 0;
272 }
273
274 static inline void mux_init(struct oprofile_operations *ops)
275 {
276         if (has_mux())
277                 ops->switch_events = nmi_switch_event;
278 }
279
280 static void mux_clone(int cpu)
281 {
282         if (!has_mux())
283                 return;
284
285         memcpy(per_cpu(cpu_msrs, cpu).multiplex,
286                per_cpu(cpu_msrs, 0).multiplex,
287                sizeof(struct op_msr) * model->num_virt_counters);
288 }
289
290 #else
291
292 inline int op_x86_phys_to_virt(int phys) { return phys; }
293 inline int op_x86_virt_to_phys(int virt) { return virt; }
294 static inline void nmi_shutdown_mux(void) { }
295 static inline int nmi_setup_mux(void) { return 1; }
296 static inline void
297 nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs) { }
298 static inline void mux_init(struct oprofile_operations *ops) { }
299 static void mux_clone(int cpu) { }
300
301 #endif
302
303 static void free_msrs(void)
304 {
305         int i;
306         for_each_possible_cpu(i) {
307                 kfree(per_cpu(cpu_msrs, i).counters);
308                 per_cpu(cpu_msrs, i).counters = NULL;
309                 kfree(per_cpu(cpu_msrs, i).controls);
310                 per_cpu(cpu_msrs, i).controls = NULL;
311         }
312         nmi_shutdown_mux();
313 }
314
315 static int allocate_msrs(void)
316 {
317         size_t controls_size = sizeof(struct op_msr) * model->num_controls;
318         size_t counters_size = sizeof(struct op_msr) * model->num_counters;
319
320         int i;
321         for_each_possible_cpu(i) {
322                 per_cpu(cpu_msrs, i).counters = kzalloc(counters_size,
323                                                         GFP_KERNEL);
324                 if (!per_cpu(cpu_msrs, i).counters)
325                         goto fail;
326                 per_cpu(cpu_msrs, i).controls = kzalloc(controls_size,
327                                                         GFP_KERNEL);
328                 if (!per_cpu(cpu_msrs, i).controls)
329                         goto fail;
330         }
331
332         if (!nmi_setup_mux())
333                 goto fail;
334
335         return 1;
336
337 fail:
338         free_msrs();
339         return 0;
340 }
341
342 static void nmi_cpu_setup(void)
343 {
344         int cpu = smp_processor_id();
345         struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
346
347         nmi_cpu_save_registers(msrs);
348         raw_spin_lock(&oprofilefs_lock);
349         model->setup_ctrs(model, msrs);
350         nmi_cpu_setup_mux(cpu, msrs);
351         raw_spin_unlock(&oprofilefs_lock);
352         per_cpu(saved_lvtpc, cpu) = apic_read(APIC_LVTPC);
353         apic_write(APIC_LVTPC, APIC_DM_NMI);
354 }
355
356 static void nmi_cpu_restore_registers(struct op_msrs *msrs)
357 {
358         struct op_msr *counters = msrs->counters;
359         struct op_msr *controls = msrs->controls;
360         unsigned int i;
361
362         for (i = 0; i < model->num_controls; ++i) {
363                 if (controls[i].addr)
364                         wrmsrl(controls[i].addr, controls[i].saved);
365         }
366
367         for (i = 0; i < model->num_counters; ++i) {
368                 if (counters[i].addr)
369                         wrmsrl(counters[i].addr, counters[i].saved);
370         }
371 }
372
373 static void nmi_cpu_shutdown(void)
374 {
375         unsigned int v;
376         int cpu = smp_processor_id();
377         struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
378
379         /* restoring APIC_LVTPC can trigger an apic error because the delivery
380          * mode and vector nr combination can be illegal. That's by design: on
381          * power on apic lvt contain a zero vector nr which are legal only for
382          * NMI delivery mode. So inhibit apic err before restoring lvtpc
383          */
384         v = apic_read(APIC_LVTERR);
385         apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
386         apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu));
387         apic_write(APIC_LVTERR, v);
388         nmi_cpu_restore_registers(msrs);
389 }
390
391 static int nmi_cpu_online(unsigned int cpu)
392 {
393         local_irq_disable();
394         if (nmi_enabled)
395                 nmi_cpu_setup();
396         if (ctr_running)
397                 nmi_cpu_start(NULL);
398         local_irq_enable();
399         return 0;
400 }
401
402 static int nmi_cpu_down_prep(unsigned int cpu)
403 {
404         local_irq_disable();
405         if (ctr_running)
406                 nmi_cpu_stop(NULL);
407         if (nmi_enabled)
408                 nmi_cpu_shutdown();
409         local_irq_enable();
410         return 0;
411 }
412
413 static int nmi_create_files(struct dentry *root)
414 {
415         unsigned int i;
416
417         for (i = 0; i < model->num_virt_counters; ++i) {
418                 struct dentry *dir;
419                 char buf[4];
420
421                 /* quick little hack to _not_ expose a counter if it is not
422                  * available for use.  This should protect userspace app.
423                  * NOTE:  assumes 1:1 mapping here (that counters are organized
424                  *        sequentially in their struct assignment).
425                  */
426                 if (!avail_to_resrv_perfctr_nmi_bit(op_x86_virt_to_phys(i)))
427                         continue;
428
429                 snprintf(buf,  sizeof(buf), "%d", i);
430                 dir = oprofilefs_mkdir(root, buf);
431                 oprofilefs_create_ulong(dir, "enabled", &counter_config[i].enabled);
432                 oprofilefs_create_ulong(dir, "event", &counter_config[i].event);
433                 oprofilefs_create_ulong(dir, "count", &counter_config[i].count);
434                 oprofilefs_create_ulong(dir, "unit_mask", &counter_config[i].unit_mask);
435                 oprofilefs_create_ulong(dir, "kernel", &counter_config[i].kernel);
436                 oprofilefs_create_ulong(dir, "user", &counter_config[i].user);
437                 oprofilefs_create_ulong(dir, "extra", &counter_config[i].extra);
438         }
439
440         return 0;
441 }
442
443 static enum cpuhp_state cpuhp_nmi_online;
444
445 static int nmi_setup(void)
446 {
447         int err = 0;
448         int cpu;
449
450         if (!allocate_msrs())
451                 return -ENOMEM;
452
453         /* We need to serialize save and setup for HT because the subset
454          * of msrs are distinct for save and setup operations
455          */
456
457         /* Assume saved/restored counters are the same on all CPUs */
458         err = model->fill_in_addresses(&per_cpu(cpu_msrs, 0));
459         if (err)
460                 goto fail;
461
462         for_each_possible_cpu(cpu) {
463                 if (!cpu)
464                         continue;
465
466                 memcpy(per_cpu(cpu_msrs, cpu).counters,
467                        per_cpu(cpu_msrs, 0).counters,
468                        sizeof(struct op_msr) * model->num_counters);
469
470                 memcpy(per_cpu(cpu_msrs, cpu).controls,
471                        per_cpu(cpu_msrs, 0).controls,
472                        sizeof(struct op_msr) * model->num_controls);
473
474                 mux_clone(cpu);
475         }
476
477         nmi_enabled = 0;
478         ctr_running = 0;
479         /* make variables visible to the nmi handler: */
480         smp_mb();
481         err = register_nmi_handler(NMI_LOCAL, profile_exceptions_notify,
482                                         0, "oprofile");
483         if (err)
484                 goto fail;
485
486         nmi_enabled = 1;
487         /* make nmi_enabled visible to the nmi handler: */
488         smp_mb();
489         err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/oprofile:online",
490                                 nmi_cpu_online, nmi_cpu_down_prep);
491         if (err < 0)
492                 goto fail_nmi;
493         cpuhp_nmi_online = err;
494         return 0;
495 fail_nmi:
496         unregister_nmi_handler(NMI_LOCAL, "oprofile");
497 fail:
498         free_msrs();
499         return err;
500 }
501
502 static void nmi_shutdown(void)
503 {
504         struct op_msrs *msrs;
505
506         cpuhp_remove_state(cpuhp_nmi_online);
507         nmi_enabled = 0;
508         ctr_running = 0;
509
510         /* make variables visible to the nmi handler: */
511         smp_mb();
512         unregister_nmi_handler(NMI_LOCAL, "oprofile");
513         msrs = &get_cpu_var(cpu_msrs);
514         model->shutdown(msrs);
515         free_msrs();
516         put_cpu_var(cpu_msrs);
517 }
518
519 #ifdef CONFIG_PM
520
521 static int nmi_suspend(void)
522 {
523         /* Only one CPU left, just stop that one */
524         if (nmi_enabled == 1)
525                 nmi_cpu_stop(NULL);
526         return 0;
527 }
528
529 static void nmi_resume(void)
530 {
531         if (nmi_enabled == 1)
532                 nmi_cpu_start(NULL);
533 }
534
535 static struct syscore_ops oprofile_syscore_ops = {
536         .resume         = nmi_resume,
537         .suspend        = nmi_suspend,
538 };
539
540 static void __init init_suspend_resume(void)
541 {
542         register_syscore_ops(&oprofile_syscore_ops);
543 }
544
545 static void exit_suspend_resume(void)
546 {
547         unregister_syscore_ops(&oprofile_syscore_ops);
548 }
549
550 #else
551
552 static inline void init_suspend_resume(void) { }
553 static inline void exit_suspend_resume(void) { }
554
555 #endif /* CONFIG_PM */
556
557 static int __init p4_init(char **cpu_type)
558 {
559         __u8 cpu_model = boot_cpu_data.x86_model;
560
561         if (cpu_model > 6 || cpu_model == 5)
562                 return 0;
563
564 #ifndef CONFIG_SMP
565         *cpu_type = "i386/p4";
566         model = &op_p4_spec;
567         return 1;
568 #else
569         switch (smp_num_siblings) {
570         case 1:
571                 *cpu_type = "i386/p4";
572                 model = &op_p4_spec;
573                 return 1;
574
575         case 2:
576                 *cpu_type = "i386/p4-ht";
577                 model = &op_p4_ht2_spec;
578                 return 1;
579         }
580 #endif
581
582         printk(KERN_INFO "oprofile: P4 HyperThreading detected with > 2 threads\n");
583         printk(KERN_INFO "oprofile: Reverting to timer mode.\n");
584         return 0;
585 }
586
587 enum __force_cpu_type {
588         reserved = 0,           /* do not force */
589         timer,
590         arch_perfmon,
591 };
592
593 static int force_cpu_type;
594
595 static int set_cpu_type(const char *str, const struct kernel_param *kp)
596 {
597         if (!strcmp(str, "timer")) {
598                 force_cpu_type = timer;
599                 printk(KERN_INFO "oprofile: forcing NMI timer mode\n");
600         } else if (!strcmp(str, "arch_perfmon")) {
601                 force_cpu_type = arch_perfmon;
602                 printk(KERN_INFO "oprofile: forcing architectural perfmon\n");
603         } else {
604                 force_cpu_type = 0;
605         }
606
607         return 0;
608 }
609 module_param_call(cpu_type, set_cpu_type, NULL, NULL, 0);
610
611 static int __init ppro_init(char **cpu_type)
612 {
613         __u8 cpu_model = boot_cpu_data.x86_model;
614         struct op_x86_model_spec *spec = &op_ppro_spec; /* default */
615
616         if (force_cpu_type == arch_perfmon && boot_cpu_has(X86_FEATURE_ARCH_PERFMON))
617                 return 0;
618
619         /*
620          * Documentation on identifying Intel processors by CPU family
621          * and model can be found in the Intel Software Developer's
622          * Manuals (SDM):
623          *
624          *  http://www.intel.com/products/processor/manuals/
625          *
626          * As of May 2010 the documentation for this was in the:
627          * "Intel 64 and IA-32 Architectures Software Developer's
628          * Manual Volume 3B: System Programming Guide", "Table B-1
629          * CPUID Signature Values of DisplayFamily_DisplayModel".
630          */
631         switch (cpu_model) {
632         case 0 ... 2:
633                 *cpu_type = "i386/ppro";
634                 break;
635         case 3 ... 5:
636                 *cpu_type = "i386/pii";
637                 break;
638         case 6 ... 8:
639         case 10 ... 11:
640                 *cpu_type = "i386/piii";
641                 break;
642         case 9:
643         case 13:
644                 *cpu_type = "i386/p6_mobile";
645                 break;
646         case 14:
647                 *cpu_type = "i386/core";
648                 break;
649         case 0x0f:
650         case 0x16:
651         case 0x17:
652         case 0x1d:
653                 *cpu_type = "i386/core_2";
654                 break;
655         case 0x1a:
656         case 0x1e:
657         case 0x2e:
658                 spec = &op_arch_perfmon_spec;
659                 *cpu_type = "i386/core_i7";
660                 break;
661         case 0x1c:
662                 *cpu_type = "i386/atom";
663                 break;
664         default:
665                 /* Unknown */
666                 return 0;
667         }
668
669         model = spec;
670         return 1;
671 }
672
673 int __init op_nmi_init(struct oprofile_operations *ops)
674 {
675         __u8 vendor = boot_cpu_data.x86_vendor;
676         __u8 family = boot_cpu_data.x86;
677         char *cpu_type = NULL;
678         int ret = 0;
679
680         if (!boot_cpu_has(X86_FEATURE_APIC))
681                 return -ENODEV;
682
683         if (force_cpu_type == timer)
684                 return -ENODEV;
685
686         switch (vendor) {
687         case X86_VENDOR_AMD:
688                 /* Needs to be at least an Athlon (or hammer in 32bit mode) */
689
690                 switch (family) {
691                 case 6:
692                         cpu_type = "i386/athlon";
693                         break;
694                 case 0xf:
695                         /*
696                          * Actually it could be i386/hammer too, but
697                          * give user space an consistent name.
698                          */
699                         cpu_type = "x86-64/hammer";
700                         break;
701                 case 0x10:
702                         cpu_type = "x86-64/family10";
703                         break;
704                 case 0x11:
705                         cpu_type = "x86-64/family11h";
706                         break;
707                 case 0x12:
708                         cpu_type = "x86-64/family12h";
709                         break;
710                 case 0x14:
711                         cpu_type = "x86-64/family14h";
712                         break;
713                 case 0x15:
714                         cpu_type = "x86-64/family15h";
715                         break;
716                 default:
717                         return -ENODEV;
718                 }
719                 model = &op_amd_spec;
720                 break;
721
722         case X86_VENDOR_INTEL:
723                 switch (family) {
724                         /* Pentium IV */
725                 case 0xf:
726                         p4_init(&cpu_type);
727                         break;
728
729                         /* A P6-class processor */
730                 case 6:
731                         ppro_init(&cpu_type);
732                         break;
733
734                 default:
735                         break;
736                 }
737
738                 if (cpu_type)
739                         break;
740
741                 if (!boot_cpu_has(X86_FEATURE_ARCH_PERFMON))
742                         return -ENODEV;
743
744                 /* use arch perfmon as fallback */
745                 cpu_type = "i386/arch_perfmon";
746                 model = &op_arch_perfmon_spec;
747                 break;
748
749         default:
750                 return -ENODEV;
751         }
752
753         /* default values, can be overwritten by model */
754         ops->create_files       = nmi_create_files;
755         ops->setup              = nmi_setup;
756         ops->shutdown           = nmi_shutdown;
757         ops->start              = nmi_start;
758         ops->stop               = nmi_stop;
759         ops->cpu_type           = cpu_type;
760
761         if (model->init)
762                 ret = model->init(ops);
763         if (ret)
764                 return ret;
765
766         if (!model->num_virt_counters)
767                 model->num_virt_counters = model->num_counters;
768
769         mux_init(ops);
770
771         init_suspend_resume();
772
773         printk(KERN_INFO "oprofile: using NMI interrupt.\n");
774         return 0;
775 }
776
777 void op_nmi_exit(void)
778 {
779         exit_suspend_resume();
780 }