Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /** |
| 2 | * @file nmi_timer_int.c |
| 3 | * |
| 4 | * @remark Copyright 2003 OProfile authors |
| 5 | * @remark Read the file COPYING |
| 6 | * |
| 7 | * @author Zwane Mwaikambo <zwane@linuxpower.ca> |
| 8 | */ |
| 9 | |
| 10 | #include <linux/init.h> |
| 11 | #include <linux/smp.h> |
Al Viro | ce3a161 | 2005-09-26 05:49:44 +0100 | [diff] [blame] | 12 | #include <linux/errno.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/oprofile.h> |
| 14 | #include <linux/rcupdate.h> |
Christoph Hellwig | 1eeb66a | 2007-05-08 00:27:03 -0700 | [diff] [blame^] | 15 | #include <linux/kdebug.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | |
| 17 | #include <asm/nmi.h> |
| 18 | #include <asm/apic.h> |
| 19 | #include <asm/ptrace.h> |
| 20 | |
Adrian Bunk | c7c19f8 | 2006-09-26 10:52:27 +0200 | [diff] [blame] | 21 | static int profile_timer_exceptions_notify(struct notifier_block *self, |
| 22 | unsigned long val, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | { |
Don Zickus | 2fbe7b2 | 2006-09-26 10:52:27 +0200 | [diff] [blame] | 24 | struct die_args *args = (struct die_args *)data; |
| 25 | int ret = NOTIFY_DONE; |
| 26 | |
| 27 | switch(val) { |
| 28 | case DIE_NMI: |
| 29 | oprofile_add_sample(args->regs, 0); |
| 30 | ret = NOTIFY_STOP; |
| 31 | break; |
| 32 | default: |
| 33 | break; |
| 34 | } |
| 35 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | } |
| 37 | |
Don Zickus | 2fbe7b2 | 2006-09-26 10:52:27 +0200 | [diff] [blame] | 38 | static struct notifier_block profile_timer_exceptions_nb = { |
| 39 | .notifier_call = profile_timer_exceptions_notify, |
| 40 | .next = NULL, |
| 41 | .priority = 0 |
| 42 | }; |
| 43 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | static int timer_start(void) |
| 45 | { |
Don Zickus | 2fbe7b2 | 2006-09-26 10:52:27 +0200 | [diff] [blame] | 46 | if (register_die_notifier(&profile_timer_exceptions_nb)) |
| 47 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | return 0; |
| 49 | } |
| 50 | |
| 51 | |
| 52 | static void timer_stop(void) |
| 53 | { |
Don Zickus | 2fbe7b2 | 2006-09-26 10:52:27 +0200 | [diff] [blame] | 54 | unregister_die_notifier(&profile_timer_exceptions_nb); |
Paul E. McKenney | fbd568a3e | 2005-05-01 08:59:04 -0700 | [diff] [blame] | 55 | synchronize_sched(); /* Allow already-started NMIs to complete. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | } |
| 57 | |
| 58 | |
David Gibson | 96d0821 | 2005-09-06 15:17:26 -0700 | [diff] [blame] | 59 | int __init op_nmi_timer_init(struct oprofile_operations * ops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | { |
Don Zickus | 2fbe7b2 | 2006-09-26 10:52:27 +0200 | [diff] [blame] | 61 | if ((nmi_watchdog != NMI_IO_APIC) || (atomic_read(&nmi_active) <= 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | return -ENODEV; |
| 63 | |
| 64 | ops->start = timer_start; |
| 65 | ops->stop = timer_stop; |
| 66 | ops->cpu_type = "timer"; |
| 67 | printk(KERN_INFO "oprofile: using NMI timer interrupt.\n"); |
| 68 | return 0; |
| 69 | } |