rcu: ignore offline CPUs in last non-dyntick-idle CPU check
[linux-2.6/btrfs-unstable.git] / arch / x86 / oprofile / nmi_int.c
blob2c505ee7101488b7032aad6f89d15ddb134457aa
1 /**
2 * @file nmi_int.c
4 * @remark Copyright 2002-2009 OProfile authors
5 * @remark Read the file COPYING
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>
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>
27 #include "op_counter.h"
28 #include "op_x86_model.h"
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);
34 /* 0 == registered but off, 1 == registered and on */
35 static int nmi_enabled = 0;
37 struct op_counter_config counter_config[OP_MAX_COUNTER];
39 /* common functions */
41 u64 op_x86_get_ctrl(struct op_x86_model_spec const *model,
42 struct op_counter_config *counter_config)
44 u64 val = 0;
45 u16 event = (u16)counter_config->event;
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;
55 return val;
59 static int profile_exceptions_notify(struct notifier_block *self,
60 unsigned long val, void *data)
62 struct die_args *args = (struct die_args *)data;
63 int ret = NOTIFY_DONE;
64 int cpu = smp_processor_id();
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;
75 return ret;
78 static void nmi_cpu_save_registers(struct op_msrs *msrs)
80 struct op_msr *counters = msrs->counters;
81 struct op_msr *controls = msrs->controls;
82 unsigned int i;
84 for (i = 0; i < model->num_counters; ++i) {
85 if (counters[i].addr)
86 rdmsrl(counters[i].addr, counters[i].saved);
89 for (i = 0; i < model->num_controls; ++i) {
90 if (controls[i].addr)
91 rdmsrl(controls[i].addr, controls[i].saved);
95 static void nmi_cpu_start(void *dummy)
97 struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
98 model->start(msrs);
101 static int nmi_start(void)
103 on_each_cpu(nmi_cpu_start, NULL, 1);
104 return 0;
107 static void nmi_cpu_stop(void *dummy)
109 struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
110 model->stop(msrs);
113 static void nmi_stop(void)
115 on_each_cpu(nmi_cpu_stop, NULL, 1);
118 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
120 static DEFINE_PER_CPU(int, switch_index);
122 static inline int has_mux(void)
124 return !!model->switch_ctrl;
127 inline int op_x86_phys_to_virt(int phys)
129 return __get_cpu_var(switch_index) + phys;
132 inline int op_x86_virt_to_phys(int virt)
134 return virt % model->num_counters;
137 static void nmi_shutdown_mux(void)
139 int i;
141 if (!has_mux())
142 return;
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;
151 static int nmi_setup_mux(void)
153 size_t multiplex_size =
154 sizeof(struct op_msr) * model->num_virt_counters;
155 int i;
157 if (!has_mux())
158 return 1;
160 for_each_possible_cpu(i) {
161 per_cpu(cpu_msrs, i).multiplex =
162 kzalloc(multiplex_size, GFP_KERNEL);
163 if (!per_cpu(cpu_msrs, i).multiplex)
164 return 0;
167 return 1;
170 static void nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs)
172 int i;
173 struct op_msr *multiplex = msrs->multiplex;
175 if (!has_mux())
176 return;
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].saved = 0;
186 per_cpu(switch_index, cpu) = 0;
189 static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs)
191 struct op_msr *counters = msrs->counters;
192 struct op_msr *multiplex = msrs->multiplex;
193 int i;
195 for (i = 0; i < model->num_counters; ++i) {
196 int virt = op_x86_phys_to_virt(i);
197 if (counters[i].addr)
198 rdmsrl(counters[i].addr, multiplex[virt].saved);
202 static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs)
204 struct op_msr *counters = msrs->counters;
205 struct op_msr *multiplex = msrs->multiplex;
206 int i;
208 for (i = 0; i < model->num_counters; ++i) {
209 int virt = op_x86_phys_to_virt(i);
210 if (counters[i].addr)
211 wrmsrl(counters[i].addr, multiplex[virt].saved);
215 static void nmi_cpu_switch(void *dummy)
217 int cpu = smp_processor_id();
218 int si = per_cpu(switch_index, cpu);
219 struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
221 nmi_cpu_stop(NULL);
222 nmi_cpu_save_mpx_registers(msrs);
224 /* move to next set */
225 si += model->num_counters;
226 if ((si >= model->num_virt_counters) || (counter_config[si].count == 0))
227 per_cpu(switch_index, cpu) = 0;
228 else
229 per_cpu(switch_index, cpu) = si;
231 model->switch_ctrl(model, msrs);
232 nmi_cpu_restore_mpx_registers(msrs);
234 nmi_cpu_start(NULL);
239 * Quick check to see if multiplexing is necessary.
240 * The check should be sufficient since counters are used
241 * in ordre.
243 static int nmi_multiplex_on(void)
245 return counter_config[model->num_counters].count ? 0 : -EINVAL;
248 static int nmi_switch_event(void)
250 if (!has_mux())
251 return -ENOSYS; /* not implemented */
252 if (nmi_multiplex_on() < 0)
253 return -EINVAL; /* not necessary */
255 on_each_cpu(nmi_cpu_switch, NULL, 1);
257 return 0;
260 static inline void mux_init(struct oprofile_operations *ops)
262 if (has_mux())
263 ops->switch_events = nmi_switch_event;
266 static void mux_clone(int cpu)
268 if (!has_mux())
269 return;
271 memcpy(per_cpu(cpu_msrs, cpu).multiplex,
272 per_cpu(cpu_msrs, 0).multiplex,
273 sizeof(struct op_msr) * model->num_virt_counters);
276 #else
278 inline int op_x86_phys_to_virt(int phys) { return phys; }
279 inline int op_x86_virt_to_phys(int virt) { return virt; }
280 static inline void nmi_shutdown_mux(void) { }
281 static inline int nmi_setup_mux(void) { return 1; }
282 static inline void
283 nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs) { }
284 static inline void mux_init(struct oprofile_operations *ops) { }
285 static void mux_clone(int cpu) { }
287 #endif
289 static void free_msrs(void)
291 int i;
292 for_each_possible_cpu(i) {
293 kfree(per_cpu(cpu_msrs, i).counters);
294 per_cpu(cpu_msrs, i).counters = NULL;
295 kfree(per_cpu(cpu_msrs, i).controls);
296 per_cpu(cpu_msrs, i).controls = NULL;
300 static int allocate_msrs(void)
302 size_t controls_size = sizeof(struct op_msr) * model->num_controls;
303 size_t counters_size = sizeof(struct op_msr) * model->num_counters;
305 int i;
306 for_each_possible_cpu(i) {
307 per_cpu(cpu_msrs, i).counters = kzalloc(counters_size,
308 GFP_KERNEL);
309 if (!per_cpu(cpu_msrs, i).counters)
310 return 0;
311 per_cpu(cpu_msrs, i).controls = kzalloc(controls_size,
312 GFP_KERNEL);
313 if (!per_cpu(cpu_msrs, i).controls)
314 return 0;
317 return 1;
320 static void nmi_cpu_setup(void *dummy)
322 int cpu = smp_processor_id();
323 struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
324 nmi_cpu_save_registers(msrs);
325 spin_lock(&oprofilefs_lock);
326 model->setup_ctrs(model, msrs);
327 nmi_cpu_setup_mux(cpu, msrs);
328 spin_unlock(&oprofilefs_lock);
329 per_cpu(saved_lvtpc, cpu) = apic_read(APIC_LVTPC);
330 apic_write(APIC_LVTPC, APIC_DM_NMI);
333 static struct notifier_block profile_exceptions_nb = {
334 .notifier_call = profile_exceptions_notify,
335 .next = NULL,
336 .priority = 2
339 static int nmi_setup(void)
341 int err = 0;
342 int cpu;
344 if (!allocate_msrs())
345 err = -ENOMEM;
346 else if (!nmi_setup_mux())
347 err = -ENOMEM;
348 else
349 err = register_die_notifier(&profile_exceptions_nb);
351 if (err) {
352 free_msrs();
353 nmi_shutdown_mux();
354 return err;
357 /* We need to serialize save and setup for HT because the subset
358 * of msrs are distinct for save and setup operations
361 /* Assume saved/restored counters are the same on all CPUs */
362 model->fill_in_addresses(&per_cpu(cpu_msrs, 0));
363 for_each_possible_cpu(cpu) {
364 if (!cpu)
365 continue;
367 memcpy(per_cpu(cpu_msrs, cpu).counters,
368 per_cpu(cpu_msrs, 0).counters,
369 sizeof(struct op_msr) * model->num_counters);
371 memcpy(per_cpu(cpu_msrs, cpu).controls,
372 per_cpu(cpu_msrs, 0).controls,
373 sizeof(struct op_msr) * model->num_controls);
375 mux_clone(cpu);
377 on_each_cpu(nmi_cpu_setup, NULL, 1);
378 nmi_enabled = 1;
379 return 0;
382 static void nmi_cpu_restore_registers(struct op_msrs *msrs)
384 struct op_msr *counters = msrs->counters;
385 struct op_msr *controls = msrs->controls;
386 unsigned int i;
388 for (i = 0; i < model->num_controls; ++i) {
389 if (controls[i].addr)
390 wrmsrl(controls[i].addr, controls[i].saved);
393 for (i = 0; i < model->num_counters; ++i) {
394 if (counters[i].addr)
395 wrmsrl(counters[i].addr, counters[i].saved);
399 static void nmi_cpu_shutdown(void *dummy)
401 unsigned int v;
402 int cpu = smp_processor_id();
403 struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
405 /* restoring APIC_LVTPC can trigger an apic error because the delivery
406 * mode and vector nr combination can be illegal. That's by design: on
407 * power on apic lvt contain a zero vector nr which are legal only for
408 * NMI delivery mode. So inhibit apic err before restoring lvtpc
410 v = apic_read(APIC_LVTERR);
411 apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
412 apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu));
413 apic_write(APIC_LVTERR, v);
414 nmi_cpu_restore_registers(msrs);
417 static void nmi_shutdown(void)
419 struct op_msrs *msrs;
421 nmi_enabled = 0;
422 on_each_cpu(nmi_cpu_shutdown, NULL, 1);
423 unregister_die_notifier(&profile_exceptions_nb);
424 nmi_shutdown_mux();
425 msrs = &get_cpu_var(cpu_msrs);
426 model->shutdown(msrs);
427 free_msrs();
428 put_cpu_var(cpu_msrs);
431 static int nmi_create_files(struct super_block *sb, struct dentry *root)
433 unsigned int i;
435 for (i = 0; i < model->num_virt_counters; ++i) {
436 struct dentry *dir;
437 char buf[4];
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).
444 if (!avail_to_resrv_perfctr_nmi_bit(op_x86_virt_to_phys(i)))
445 continue;
447 snprintf(buf, sizeof(buf), "%d", i);
448 dir = oprofilefs_mkdir(sb, root, buf);
449 oprofilefs_create_ulong(sb, dir, "enabled", &counter_config[i].enabled);
450 oprofilefs_create_ulong(sb, dir, "event", &counter_config[i].event);
451 oprofilefs_create_ulong(sb, dir, "count", &counter_config[i].count);
452 oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask);
453 oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel);
454 oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user);
457 return 0;
460 #ifdef CONFIG_SMP
461 static int oprofile_cpu_notifier(struct notifier_block *b, unsigned long action,
462 void *data)
464 int cpu = (unsigned long)data;
465 switch (action) {
466 case CPU_DOWN_FAILED:
467 case CPU_ONLINE:
468 smp_call_function_single(cpu, nmi_cpu_start, NULL, 0);
469 break;
470 case CPU_DOWN_PREPARE:
471 smp_call_function_single(cpu, nmi_cpu_stop, NULL, 1);
472 break;
474 return NOTIFY_DONE;
477 static struct notifier_block oprofile_cpu_nb = {
478 .notifier_call = oprofile_cpu_notifier
480 #endif
482 #ifdef CONFIG_PM
484 static int nmi_suspend(struct sys_device *dev, pm_message_t state)
486 /* Only one CPU left, just stop that one */
487 if (nmi_enabled == 1)
488 nmi_cpu_stop(NULL);
489 return 0;
492 static int nmi_resume(struct sys_device *dev)
494 if (nmi_enabled == 1)
495 nmi_cpu_start(NULL);
496 return 0;
499 static struct sysdev_class oprofile_sysclass = {
500 .name = "oprofile",
501 .resume = nmi_resume,
502 .suspend = nmi_suspend,
505 static struct sys_device device_oprofile = {
506 .id = 0,
507 .cls = &oprofile_sysclass,
510 static int __init init_sysfs(void)
512 int error;
514 error = sysdev_class_register(&oprofile_sysclass);
515 if (!error)
516 error = sysdev_register(&device_oprofile);
517 return error;
520 static void exit_sysfs(void)
522 sysdev_unregister(&device_oprofile);
523 sysdev_class_unregister(&oprofile_sysclass);
526 #else
527 #define init_sysfs() do { } while (0)
528 #define exit_sysfs() do { } while (0)
529 #endif /* CONFIG_PM */
531 static int __init p4_init(char **cpu_type)
533 __u8 cpu_model = boot_cpu_data.x86_model;
535 if (cpu_model > 6 || cpu_model == 5)
536 return 0;
538 #ifndef CONFIG_SMP
539 *cpu_type = "i386/p4";
540 model = &op_p4_spec;
541 return 1;
542 #else
543 switch (smp_num_siblings) {
544 case 1:
545 *cpu_type = "i386/p4";
546 model = &op_p4_spec;
547 return 1;
549 case 2:
550 *cpu_type = "i386/p4-ht";
551 model = &op_p4_ht2_spec;
552 return 1;
554 #endif
556 printk(KERN_INFO "oprofile: P4 HyperThreading detected with > 2 threads\n");
557 printk(KERN_INFO "oprofile: Reverting to timer mode.\n");
558 return 0;
561 static int force_arch_perfmon;
562 static int force_cpu_type(const char *str, struct kernel_param *kp)
564 if (!strcmp(str, "arch_perfmon")) {
565 force_arch_perfmon = 1;
566 printk(KERN_INFO "oprofile: forcing architectural perfmon\n");
569 return 0;
571 module_param_call(cpu_type, force_cpu_type, NULL, NULL, 0);
573 static int __init ppro_init(char **cpu_type)
575 __u8 cpu_model = boot_cpu_data.x86_model;
576 struct op_x86_model_spec *spec = &op_ppro_spec; /* default */
578 if (force_arch_perfmon && cpu_has_arch_perfmon)
579 return 0;
581 switch (cpu_model) {
582 case 0 ... 2:
583 *cpu_type = "i386/ppro";
584 break;
585 case 3 ... 5:
586 *cpu_type = "i386/pii";
587 break;
588 case 6 ... 8:
589 case 10 ... 11:
590 *cpu_type = "i386/piii";
591 break;
592 case 9:
593 case 13:
594 *cpu_type = "i386/p6_mobile";
595 break;
596 case 14:
597 *cpu_type = "i386/core";
598 break;
599 case 15: case 23:
600 *cpu_type = "i386/core_2";
601 break;
602 case 0x2e:
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;
615 model = spec;
616 return 1;
619 /* in order to get sysfs right */
620 static int using_nmi;
622 int __init op_nmi_init(struct oprofile_operations *ops)
624 __u8 vendor = boot_cpu_data.x86_vendor;
625 __u8 family = boot_cpu_data.x86;
626 char *cpu_type = NULL;
627 int ret = 0;
629 if (!cpu_has_apic)
630 return -ENODEV;
632 switch (vendor) {
633 case X86_VENDOR_AMD:
634 /* Needs to be at least an Athlon (or hammer in 32bit mode) */
636 switch (family) {
637 case 6:
638 cpu_type = "i386/athlon";
639 break;
640 case 0xf:
642 * Actually it could be i386/hammer too, but
643 * give user space an consistent name.
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;
656 model = &op_amd_spec;
657 break;
659 case X86_VENDOR_INTEL:
660 switch (family) {
661 /* Pentium IV */
662 case 0xf:
663 p4_init(&cpu_type);
664 break;
666 /* A P6-class processor */
667 case 6:
668 ppro_init(&cpu_type);
669 break;
671 default:
672 break;
675 if (cpu_type)
676 break;
678 if (!cpu_has_arch_perfmon)
679 return -ENODEV;
681 /* use arch perfmon as fallback */
682 cpu_type = "i386/arch_perfmon";
683 model = &op_arch_perfmon_spec;
684 break;
686 default:
687 return -ENODEV;
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;
701 if (model->init)
702 ret = model->init(ops);
703 if (ret)
704 return ret;
706 if (!model->num_virt_counters)
707 model->num_virt_counters = model->num_counters;
709 mux_init(ops);
711 init_sysfs();
712 using_nmi = 1;
713 printk(KERN_INFO "oprofile: using NMI interrupt.\n");
714 return 0;
717 void op_nmi_exit(void)
719 if (using_nmi) {
720 exit_sysfs();
721 #ifdef CONFIG_SMP
722 unregister_cpu_notifier(&oprofile_cpu_nb);
723 #endif
725 if (model->exit)
726 model->exit();