70 lines
1.4 KiB
C
70 lines
1.4 KiB
C
/**
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* @file nmi_timer_int.c
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*
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* @remark Copyright 2003 OProfile authors
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* @remark Read the file COPYING
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*
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* @author Zwane Mwaikambo <zwane@linuxpower.ca>
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*/
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#include <linux/init.h>
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#include <linux/smp.h>
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#include <linux/errno.h>
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#include <linux/oprofile.h>
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#include <linux/rcupdate.h>
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#include <linux/kdebug.h>
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#include <asm/nmi.h>
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#include <asm/apic.h>
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#include <asm/ptrace.h>
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static int profile_timer_exceptions_notify(struct notifier_block *self,
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unsigned long val, void *data)
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{
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struct die_args *args = (struct die_args *)data;
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int ret = NOTIFY_DONE;
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switch (val) {
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case DIE_NMI:
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oprofile_add_sample(args->regs, 0);
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ret = NOTIFY_STOP;
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break;
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default:
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break;
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}
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return ret;
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}
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static struct notifier_block profile_timer_exceptions_nb = {
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.notifier_call = profile_timer_exceptions_notify,
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.next = NULL,
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.priority = 0
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};
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static int timer_start(void)
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{
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if (register_die_notifier(&profile_timer_exceptions_nb))
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return 1;
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return 0;
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}
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static void timer_stop(void)
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{
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unregister_die_notifier(&profile_timer_exceptions_nb);
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synchronize_sched(); /* Allow already-started NMIs to complete. */
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}
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int __init op_nmi_timer_init(struct oprofile_operations *ops)
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{
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if ((nmi_watchdog != NMI_IO_APIC) || (atomic_read(&nmi_active) <= 0))
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return -ENODEV;
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ops->start = timer_start;
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ops->stop = timer_stop;
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ops->cpu_type = "timer";
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printk(KERN_INFO "oprofile: using NMI timer interrupt.\n");
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return 0;
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}
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