vmstat: User per cpu atomics to avoid interrupt disable / enable
[deliverable/linux.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/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 /* 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 event &= model->event_mask ? model->event_mask : 0xFF;
53 val |= event & 0xFF;
54 val |= (event & 0x0F00) << 24;
55
56 return val;
57 }
58
59
60 static int profile_exceptions_notify(struct notifier_block *self,
61 unsigned long val, void *data)
62 {
63 struct die_args *args = (struct die_args *)data;
64 int ret = NOTIFY_DONE;
65
66 switch (val) {
67 case DIE_NMI:
68 case DIE_NMI_IPI:
69 if (ctr_running)
70 model->check_ctrs(args->regs, &__get_cpu_var(cpu_msrs));
71 else if (!nmi_enabled)
72 break;
73 else
74 model->stop(&__get_cpu_var(cpu_msrs));
75 ret = NOTIFY_STOP;
76 break;
77 default:
78 break;
79 }
80 return ret;
81 }
82
83 static void nmi_cpu_save_registers(struct op_msrs *msrs)
84 {
85 struct op_msr *counters = msrs->counters;
86 struct op_msr *controls = msrs->controls;
87 unsigned int i;
88
89 for (i = 0; i < model->num_counters; ++i) {
90 if (counters[i].addr)
91 rdmsrl(counters[i].addr, counters[i].saved);
92 }
93
94 for (i = 0; i < model->num_controls; ++i) {
95 if (controls[i].addr)
96 rdmsrl(controls[i].addr, controls[i].saved);
97 }
98 }
99
100 static void nmi_cpu_start(void *dummy)
101 {
102 struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
103 if (!msrs->controls)
104 WARN_ON_ONCE(1);
105 else
106 model->start(msrs);
107 }
108
109 static int nmi_start(void)
110 {
111 get_online_cpus();
112 on_each_cpu(nmi_cpu_start, NULL, 1);
113 ctr_running = 1;
114 put_online_cpus();
115 return 0;
116 }
117
118 static void nmi_cpu_stop(void *dummy)
119 {
120 struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
121 if (!msrs->controls)
122 WARN_ON_ONCE(1);
123 else
124 model->stop(msrs);
125 }
126
127 static void nmi_stop(void)
128 {
129 get_online_cpus();
130 on_each_cpu(nmi_cpu_stop, NULL, 1);
131 ctr_running = 0;
132 put_online_cpus();
133 }
134
135 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
136
137 static DEFINE_PER_CPU(int, switch_index);
138
139 static inline int has_mux(void)
140 {
141 return !!model->switch_ctrl;
142 }
143
144 inline int op_x86_phys_to_virt(int phys)
145 {
146 return __get_cpu_var(switch_index) + phys;
147 }
148
149 inline int op_x86_virt_to_phys(int virt)
150 {
151 return virt % model->num_counters;
152 }
153
154 static void nmi_shutdown_mux(void)
155 {
156 int i;
157
158 if (!has_mux())
159 return;
160
161 for_each_possible_cpu(i) {
162 kfree(per_cpu(cpu_msrs, i).multiplex);
163 per_cpu(cpu_msrs, i).multiplex = NULL;
164 per_cpu(switch_index, i) = 0;
165 }
166 }
167
168 static int nmi_setup_mux(void)
169 {
170 size_t multiplex_size =
171 sizeof(struct op_msr) * model->num_virt_counters;
172 int i;
173
174 if (!has_mux())
175 return 1;
176
177 for_each_possible_cpu(i) {
178 per_cpu(cpu_msrs, i).multiplex =
179 kzalloc(multiplex_size, GFP_KERNEL);
180 if (!per_cpu(cpu_msrs, i).multiplex)
181 return 0;
182 }
183
184 return 1;
185 }
186
187 static void nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs)
188 {
189 int i;
190 struct op_msr *multiplex = msrs->multiplex;
191
192 if (!has_mux())
193 return;
194
195 for (i = 0; i < model->num_virt_counters; ++i) {
196 if (counter_config[i].enabled) {
197 multiplex[i].saved = -(u64)counter_config[i].count;
198 } else {
199 multiplex[i].saved = 0;
200 }
201 }
202
203 per_cpu(switch_index, cpu) = 0;
204 }
205
206 static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs)
207 {
208 struct op_msr *counters = msrs->counters;
209 struct op_msr *multiplex = msrs->multiplex;
210 int i;
211
212 for (i = 0; i < model->num_counters; ++i) {
213 int virt = op_x86_phys_to_virt(i);
214 if (counters[i].addr)
215 rdmsrl(counters[i].addr, multiplex[virt].saved);
216 }
217 }
218
219 static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs)
220 {
221 struct op_msr *counters = msrs->counters;
222 struct op_msr *multiplex = msrs->multiplex;
223 int i;
224
225 for (i = 0; i < model->num_counters; ++i) {
226 int virt = op_x86_phys_to_virt(i);
227 if (counters[i].addr)
228 wrmsrl(counters[i].addr, multiplex[virt].saved);
229 }
230 }
231
232 static void nmi_cpu_switch(void *dummy)
233 {
234 int cpu = smp_processor_id();
235 int si = per_cpu(switch_index, cpu);
236 struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
237
238 nmi_cpu_stop(NULL);
239 nmi_cpu_save_mpx_registers(msrs);
240
241 /* move to next set */
242 si += model->num_counters;
243 if ((si >= model->num_virt_counters) || (counter_config[si].count == 0))
244 per_cpu(switch_index, cpu) = 0;
245 else
246 per_cpu(switch_index, cpu) = si;
247
248 model->switch_ctrl(model, msrs);
249 nmi_cpu_restore_mpx_registers(msrs);
250
251 nmi_cpu_start(NULL);
252 }
253
254
255 /*
256 * Quick check to see if multiplexing is necessary.
257 * The check should be sufficient since counters are used
258 * in ordre.
259 */
260 static int nmi_multiplex_on(void)
261 {
262 return counter_config[model->num_counters].count ? 0 : -EINVAL;
263 }
264
265 static int nmi_switch_event(void)
266 {
267 if (!has_mux())
268 return -ENOSYS; /* not implemented */
269 if (nmi_multiplex_on() < 0)
270 return -EINVAL; /* not necessary */
271
272 get_online_cpus();
273 if (ctr_running)
274 on_each_cpu(nmi_cpu_switch, NULL, 1);
275 put_online_cpus();
276
277 return 0;
278 }
279
280 static inline void mux_init(struct oprofile_operations *ops)
281 {
282 if (has_mux())
283 ops->switch_events = nmi_switch_event;
284 }
285
286 static void mux_clone(int cpu)
287 {
288 if (!has_mux())
289 return;
290
291 memcpy(per_cpu(cpu_msrs, cpu).multiplex,
292 per_cpu(cpu_msrs, 0).multiplex,
293 sizeof(struct op_msr) * model->num_virt_counters);
294 }
295
296 #else
297
298 inline int op_x86_phys_to_virt(int phys) { return phys; }
299 inline int op_x86_virt_to_phys(int virt) { return virt; }
300 static inline void nmi_shutdown_mux(void) { }
301 static inline int nmi_setup_mux(void) { return 1; }
302 static inline void
303 nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs) { }
304 static inline void mux_init(struct oprofile_operations *ops) { }
305 static void mux_clone(int cpu) { }
306
307 #endif
308
309 static void free_msrs(void)
310 {
311 int i;
312 for_each_possible_cpu(i) {
313 kfree(per_cpu(cpu_msrs, i).counters);
314 per_cpu(cpu_msrs, i).counters = NULL;
315 kfree(per_cpu(cpu_msrs, i).controls);
316 per_cpu(cpu_msrs, i).controls = NULL;
317 }
318 nmi_shutdown_mux();
319 }
320
321 static int allocate_msrs(void)
322 {
323 size_t controls_size = sizeof(struct op_msr) * model->num_controls;
324 size_t counters_size = sizeof(struct op_msr) * model->num_counters;
325
326 int i;
327 for_each_possible_cpu(i) {
328 per_cpu(cpu_msrs, i).counters = kzalloc(counters_size,
329 GFP_KERNEL);
330 if (!per_cpu(cpu_msrs, i).counters)
331 goto fail;
332 per_cpu(cpu_msrs, i).controls = kzalloc(controls_size,
333 GFP_KERNEL);
334 if (!per_cpu(cpu_msrs, i).controls)
335 goto fail;
336 }
337
338 if (!nmi_setup_mux())
339 goto fail;
340
341 return 1;
342
343 fail:
344 free_msrs();
345 return 0;
346 }
347
348 static void nmi_cpu_setup(void *dummy)
349 {
350 int cpu = smp_processor_id();
351 struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
352 nmi_cpu_save_registers(msrs);
353 spin_lock(&oprofilefs_lock);
354 model->setup_ctrs(model, msrs);
355 nmi_cpu_setup_mux(cpu, msrs);
356 spin_unlock(&oprofilefs_lock);
357 per_cpu(saved_lvtpc, cpu) = apic_read(APIC_LVTPC);
358 apic_write(APIC_LVTPC, APIC_DM_NMI);
359 }
360
361 static struct notifier_block profile_exceptions_nb = {
362 .notifier_call = profile_exceptions_notify,
363 .next = NULL,
364 .priority = 2
365 };
366
367 static void nmi_cpu_restore_registers(struct op_msrs *msrs)
368 {
369 struct op_msr *counters = msrs->counters;
370 struct op_msr *controls = msrs->controls;
371 unsigned int i;
372
373 for (i = 0; i < model->num_controls; ++i) {
374 if (controls[i].addr)
375 wrmsrl(controls[i].addr, controls[i].saved);
376 }
377
378 for (i = 0; i < model->num_counters; ++i) {
379 if (counters[i].addr)
380 wrmsrl(counters[i].addr, counters[i].saved);
381 }
382 }
383
384 static void nmi_cpu_shutdown(void *dummy)
385 {
386 unsigned int v;
387 int cpu = smp_processor_id();
388 struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
389
390 /* restoring APIC_LVTPC can trigger an apic error because the delivery
391 * mode and vector nr combination can be illegal. That's by design: on
392 * power on apic lvt contain a zero vector nr which are legal only for
393 * NMI delivery mode. So inhibit apic err before restoring lvtpc
394 */
395 v = apic_read(APIC_LVTERR);
396 apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
397 apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu));
398 apic_write(APIC_LVTERR, v);
399 nmi_cpu_restore_registers(msrs);
400 if (model->cpu_down)
401 model->cpu_down();
402 }
403
404 static void nmi_cpu_up(void *dummy)
405 {
406 if (nmi_enabled)
407 nmi_cpu_setup(dummy);
408 if (ctr_running)
409 nmi_cpu_start(dummy);
410 }
411
412 static void nmi_cpu_down(void *dummy)
413 {
414 if (ctr_running)
415 nmi_cpu_stop(dummy);
416 if (nmi_enabled)
417 nmi_cpu_shutdown(dummy);
418 }
419
420 static int nmi_create_files(struct super_block *sb, struct dentry *root)
421 {
422 unsigned int i;
423
424 for (i = 0; i < model->num_virt_counters; ++i) {
425 struct dentry *dir;
426 char buf[4];
427
428 /* quick little hack to _not_ expose a counter if it is not
429 * available for use. This should protect userspace app.
430 * NOTE: assumes 1:1 mapping here (that counters are organized
431 * sequentially in their struct assignment).
432 */
433 if (!avail_to_resrv_perfctr_nmi_bit(op_x86_virt_to_phys(i)))
434 continue;
435
436 snprintf(buf, sizeof(buf), "%d", i);
437 dir = oprofilefs_mkdir(sb, root, buf);
438 oprofilefs_create_ulong(sb, dir, "enabled", &counter_config[i].enabled);
439 oprofilefs_create_ulong(sb, dir, "event", &counter_config[i].event);
440 oprofilefs_create_ulong(sb, dir, "count", &counter_config[i].count);
441 oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask);
442 oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel);
443 oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user);
444 }
445
446 return 0;
447 }
448
449 static int oprofile_cpu_notifier(struct notifier_block *b, unsigned long action,
450 void *data)
451 {
452 int cpu = (unsigned long)data;
453 switch (action) {
454 case CPU_DOWN_FAILED:
455 case CPU_ONLINE:
456 smp_call_function_single(cpu, nmi_cpu_up, NULL, 0);
457 break;
458 case CPU_DOWN_PREPARE:
459 smp_call_function_single(cpu, nmi_cpu_down, NULL, 1);
460 break;
461 }
462 return NOTIFY_DONE;
463 }
464
465 static struct notifier_block oprofile_cpu_nb = {
466 .notifier_call = oprofile_cpu_notifier
467 };
468
469 static int nmi_setup(void)
470 {
471 int err = 0;
472 int cpu;
473
474 if (!allocate_msrs())
475 return -ENOMEM;
476
477 /* We need to serialize save and setup for HT because the subset
478 * of msrs are distinct for save and setup operations
479 */
480
481 /* Assume saved/restored counters are the same on all CPUs */
482 err = model->fill_in_addresses(&per_cpu(cpu_msrs, 0));
483 if (err)
484 goto fail;
485
486 for_each_possible_cpu(cpu) {
487 if (!cpu)
488 continue;
489
490 memcpy(per_cpu(cpu_msrs, cpu).counters,
491 per_cpu(cpu_msrs, 0).counters,
492 sizeof(struct op_msr) * model->num_counters);
493
494 memcpy(per_cpu(cpu_msrs, cpu).controls,
495 per_cpu(cpu_msrs, 0).controls,
496 sizeof(struct op_msr) * model->num_controls);
497
498 mux_clone(cpu);
499 }
500
501 nmi_enabled = 0;
502 ctr_running = 0;
503 barrier();
504 err = register_die_notifier(&profile_exceptions_nb);
505 if (err)
506 goto fail;
507
508 get_online_cpus();
509 register_cpu_notifier(&oprofile_cpu_nb);
510 on_each_cpu(nmi_cpu_setup, NULL, 1);
511 nmi_enabled = 1;
512 put_online_cpus();
513
514 return 0;
515 fail:
516 free_msrs();
517 return err;
518 }
519
520 static void nmi_shutdown(void)
521 {
522 struct op_msrs *msrs;
523
524 get_online_cpus();
525 unregister_cpu_notifier(&oprofile_cpu_nb);
526 on_each_cpu(nmi_cpu_shutdown, NULL, 1);
527 nmi_enabled = 0;
528 ctr_running = 0;
529 put_online_cpus();
530 barrier();
531 unregister_die_notifier(&profile_exceptions_nb);
532 msrs = &get_cpu_var(cpu_msrs);
533 model->shutdown(msrs);
534 free_msrs();
535 put_cpu_var(cpu_msrs);
536 }
537
538 #ifdef CONFIG_PM
539
540 static int nmi_suspend(struct sys_device *dev, pm_message_t state)
541 {
542 /* Only one CPU left, just stop that one */
543 if (nmi_enabled == 1)
544 nmi_cpu_stop(NULL);
545 return 0;
546 }
547
548 static int nmi_resume(struct sys_device *dev)
549 {
550 if (nmi_enabled == 1)
551 nmi_cpu_start(NULL);
552 return 0;
553 }
554
555 static struct sysdev_class oprofile_sysclass = {
556 .name = "oprofile",
557 .resume = nmi_resume,
558 .suspend = nmi_suspend,
559 };
560
561 static struct sys_device device_oprofile = {
562 .id = 0,
563 .cls = &oprofile_sysclass,
564 };
565
566 static int __init init_sysfs(void)
567 {
568 int error;
569
570 error = sysdev_class_register(&oprofile_sysclass);
571 if (error)
572 return error;
573
574 error = sysdev_register(&device_oprofile);
575 if (error)
576 sysdev_class_unregister(&oprofile_sysclass);
577
578 return error;
579 }
580
581 static void exit_sysfs(void)
582 {
583 sysdev_unregister(&device_oprofile);
584 sysdev_class_unregister(&oprofile_sysclass);
585 }
586
587 #else
588
589 static inline int init_sysfs(void) { return 0; }
590 static inline void exit_sysfs(void) { }
591
592 #endif /* CONFIG_PM */
593
594 static int __init p4_init(char **cpu_type)
595 {
596 __u8 cpu_model = boot_cpu_data.x86_model;
597
598 if (cpu_model > 6 || cpu_model == 5)
599 return 0;
600
601 #ifndef CONFIG_SMP
602 *cpu_type = "i386/p4";
603 model = &op_p4_spec;
604 return 1;
605 #else
606 switch (smp_num_siblings) {
607 case 1:
608 *cpu_type = "i386/p4";
609 model = &op_p4_spec;
610 return 1;
611
612 case 2:
613 *cpu_type = "i386/p4-ht";
614 model = &op_p4_ht2_spec;
615 return 1;
616 }
617 #endif
618
619 printk(KERN_INFO "oprofile: P4 HyperThreading detected with > 2 threads\n");
620 printk(KERN_INFO "oprofile: Reverting to timer mode.\n");
621 return 0;
622 }
623
624 static int force_arch_perfmon;
625 static int force_cpu_type(const char *str, struct kernel_param *kp)
626 {
627 if (!strcmp(str, "arch_perfmon")) {
628 force_arch_perfmon = 1;
629 printk(KERN_INFO "oprofile: forcing architectural perfmon\n");
630 }
631
632 return 0;
633 }
634 module_param_call(cpu_type, force_cpu_type, NULL, NULL, 0);
635
636 static int __init ppro_init(char **cpu_type)
637 {
638 __u8 cpu_model = boot_cpu_data.x86_model;
639 struct op_x86_model_spec *spec = &op_ppro_spec; /* default */
640
641 if (force_arch_perfmon && cpu_has_arch_perfmon)
642 return 0;
643
644 /*
645 * Documentation on identifying Intel processors by CPU family
646 * and model can be found in the Intel Software Developer's
647 * Manuals (SDM):
648 *
649 * http://www.intel.com/products/processor/manuals/
650 *
651 * As of May 2010 the documentation for this was in the:
652 * "Intel 64 and IA-32 Architectures Software Developer's
653 * Manual Volume 3B: System Programming Guide", "Table B-1
654 * CPUID Signature Values of DisplayFamily_DisplayModel".
655 */
656 switch (cpu_model) {
657 case 0 ... 2:
658 *cpu_type = "i386/ppro";
659 break;
660 case 3 ... 5:
661 *cpu_type = "i386/pii";
662 break;
663 case 6 ... 8:
664 case 10 ... 11:
665 *cpu_type = "i386/piii";
666 break;
667 case 9:
668 case 13:
669 *cpu_type = "i386/p6_mobile";
670 break;
671 case 14:
672 *cpu_type = "i386/core";
673 break;
674 case 0x0f:
675 case 0x16:
676 case 0x17:
677 case 0x1d:
678 *cpu_type = "i386/core_2";
679 break;
680 case 0x1a:
681 case 0x1e:
682 case 0x2e:
683 spec = &op_arch_perfmon_spec;
684 *cpu_type = "i386/core_i7";
685 break;
686 case 0x1c:
687 *cpu_type = "i386/atom";
688 break;
689 default:
690 /* Unknown */
691 return 0;
692 }
693
694 model = spec;
695 return 1;
696 }
697
698 int __init op_nmi_init(struct oprofile_operations *ops)
699 {
700 __u8 vendor = boot_cpu_data.x86_vendor;
701 __u8 family = boot_cpu_data.x86;
702 char *cpu_type = NULL;
703 int ret = 0;
704
705 if (!cpu_has_apic)
706 return -ENODEV;
707
708 switch (vendor) {
709 case X86_VENDOR_AMD:
710 /* Needs to be at least an Athlon (or hammer in 32bit mode) */
711
712 switch (family) {
713 case 6:
714 cpu_type = "i386/athlon";
715 break;
716 case 0xf:
717 /*
718 * Actually it could be i386/hammer too, but
719 * give user space an consistent name.
720 */
721 cpu_type = "x86-64/hammer";
722 break;
723 case 0x10:
724 cpu_type = "x86-64/family10";
725 break;
726 case 0x11:
727 cpu_type = "x86-64/family11h";
728 break;
729 case 0x12:
730 cpu_type = "x86-64/family12h";
731 break;
732 case 0x14:
733 cpu_type = "x86-64/family14h";
734 break;
735 default:
736 return -ENODEV;
737 }
738 model = &op_amd_spec;
739 break;
740
741 case X86_VENDOR_INTEL:
742 switch (family) {
743 /* Pentium IV */
744 case 0xf:
745 p4_init(&cpu_type);
746 break;
747
748 /* A P6-class processor */
749 case 6:
750 ppro_init(&cpu_type);
751 break;
752
753 default:
754 break;
755 }
756
757 if (cpu_type)
758 break;
759
760 if (!cpu_has_arch_perfmon)
761 return -ENODEV;
762
763 /* use arch perfmon as fallback */
764 cpu_type = "i386/arch_perfmon";
765 model = &op_arch_perfmon_spec;
766 break;
767
768 default:
769 return -ENODEV;
770 }
771
772 /* default values, can be overwritten by model */
773 ops->create_files = nmi_create_files;
774 ops->setup = nmi_setup;
775 ops->shutdown = nmi_shutdown;
776 ops->start = nmi_start;
777 ops->stop = nmi_stop;
778 ops->cpu_type = cpu_type;
779
780 if (model->init)
781 ret = model->init(ops);
782 if (ret)
783 return ret;
784
785 if (!model->num_virt_counters)
786 model->num_virt_counters = model->num_counters;
787
788 mux_init(ops);
789
790 ret = init_sysfs();
791 if (ret)
792 return ret;
793
794 printk(KERN_INFO "oprofile: using NMI interrupt.\n");
795 return 0;
796 }
797
798 void op_nmi_exit(void)
799 {
800 exit_sysfs();
801 }
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