| 1 | /** |
| 2 | * @file timer_int.c |
| 3 | * |
| 4 | * @remark Copyright 2002 OProfile authors |
| 5 | * @remark Read the file COPYING |
| 6 | * |
| 7 | * @author John Levon <levon@movementarian.org> |
| 8 | */ |
| 9 | |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/notifier.h> |
| 12 | #include <linux/smp.h> |
| 13 | #include <linux/oprofile.h> |
| 14 | #include <linux/profile.h> |
| 15 | #include <linux/init.h> |
| 16 | #include <linux/cpu.h> |
| 17 | #include <linux/hrtimer.h> |
| 18 | #include <asm/irq_regs.h> |
| 19 | #include <asm/ptrace.h> |
| 20 | |
| 21 | #include "oprof.h" |
| 22 | |
| 23 | static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer); |
| 24 | |
| 25 | static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer) |
| 26 | { |
| 27 | oprofile_add_sample(get_irq_regs(), 0); |
| 28 | hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC)); |
| 29 | return HRTIMER_RESTART; |
| 30 | } |
| 31 | |
| 32 | static void __oprofile_hrtimer_start(void *unused) |
| 33 | { |
| 34 | struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer); |
| 35 | |
| 36 | hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
| 37 | hrtimer->function = oprofile_hrtimer_notify; |
| 38 | |
| 39 | hrtimer_start(hrtimer, ns_to_ktime(TICK_NSEC), |
| 40 | HRTIMER_MODE_REL_PINNED); |
| 41 | } |
| 42 | |
| 43 | static int oprofile_hrtimer_start(void) |
| 44 | { |
| 45 | on_each_cpu(__oprofile_hrtimer_start, NULL, 1); |
| 46 | return 0; |
| 47 | } |
| 48 | |
| 49 | static void __oprofile_hrtimer_stop(int cpu) |
| 50 | { |
| 51 | struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu); |
| 52 | |
| 53 | hrtimer_cancel(hrtimer); |
| 54 | } |
| 55 | |
| 56 | static void oprofile_hrtimer_stop(void) |
| 57 | { |
| 58 | int cpu; |
| 59 | |
| 60 | for_each_online_cpu(cpu) |
| 61 | __oprofile_hrtimer_stop(cpu); |
| 62 | } |
| 63 | |
| 64 | static int __cpuinit oprofile_cpu_notify(struct notifier_block *self, |
| 65 | unsigned long action, void *hcpu) |
| 66 | { |
| 67 | long cpu = (long) hcpu; |
| 68 | |
| 69 | switch (action) { |
| 70 | case CPU_ONLINE: |
| 71 | case CPU_ONLINE_FROZEN: |
| 72 | smp_call_function_single(cpu, __oprofile_hrtimer_start, |
| 73 | NULL, 1); |
| 74 | break; |
| 75 | case CPU_DEAD: |
| 76 | case CPU_DEAD_FROZEN: |
| 77 | __oprofile_hrtimer_stop(cpu); |
| 78 | break; |
| 79 | } |
| 80 | return NOTIFY_OK; |
| 81 | } |
| 82 | |
| 83 | static struct notifier_block __refdata oprofile_cpu_notifier = { |
| 84 | .notifier_call = oprofile_cpu_notify, |
| 85 | }; |
| 86 | |
| 87 | int __init oprofile_timer_init(struct oprofile_operations *ops) |
| 88 | { |
| 89 | int rc; |
| 90 | |
| 91 | rc = register_hotcpu_notifier(&oprofile_cpu_notifier); |
| 92 | if (rc) |
| 93 | return rc; |
| 94 | ops->create_files = NULL; |
| 95 | ops->setup = NULL; |
| 96 | ops->shutdown = NULL; |
| 97 | ops->start = oprofile_hrtimer_start; |
| 98 | ops->stop = oprofile_hrtimer_stop; |
| 99 | ops->cpu_type = "timer"; |
| 100 | return 0; |
| 101 | } |
| 102 | |
| 103 | void __exit oprofile_timer_exit(void) |
| 104 | { |
| 105 | unregister_hotcpu_notifier(&oprofile_cpu_notifier); |
| 106 | } |