zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/kernel/watchdog.c b/ap/os/linux/linux-3.4.x/kernel/watchdog.c
new file mode 100644
index 0000000..c3c97e4
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/kernel/watchdog.c
@@ -0,0 +1,620 @@
+/*
+ * Detect hard and soft lockups on a system
+ *
+ * started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
+ *
+ * Note: Most of this code is borrowed heavily from the original softlockup
+ * detector, so thanks to Ingo for the initial implementation.
+ * Some chunks also taken from the old x86-specific nmi watchdog code, thanks
+ * to those contributors as well.
+ */
+
+#define pr_fmt(fmt) "NMI watchdog: " fmt
+
+#include <linux/mm.h>
+#include <linux/cpu.h>
+#include <linux/nmi.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/freezer.h>
+#include <linux/kthread.h>
+#include <linux/lockdep.h>
+#include <linux/notifier.h>
+#include <linux/module.h>
+#include <linux/sysctl.h>
+
+#include <asm/irq_regs.h>
+#include <linux/perf_event.h>
+
+int watchdog_enabled = 1;
+int __read_mostly watchdog_thresh = 10;
+
+static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts);
+static DEFINE_PER_CPU(struct task_struct *, softlockup_watchdog);
+static DEFINE_PER_CPU(struct hrtimer, watchdog_hrtimer);
+static DEFINE_PER_CPU(bool, softlockup_touch_sync);
+static DEFINE_PER_CPU(bool, soft_watchdog_warn);
+#ifdef CONFIG_HARDLOCKUP_DETECTOR
+static DEFINE_PER_CPU(bool, hard_watchdog_warn);
+static DEFINE_PER_CPU(bool, watchdog_nmi_touch);
+static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts);
+static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
+#endif
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_NMI
+static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
+#endif
+
+/* boot commands */
+/*
+ * Should we panic when a soft-lockup or hard-lockup occurs:
+ */
+#ifdef CONFIG_HARDLOCKUP_DETECTOR
+static int hardlockup_panic =
+ CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE;
+
+static int __init hardlockup_panic_setup(char *str)
+{
+ if (!strncmp(str, "panic", 5))
+ hardlockup_panic = 1;
+ else if (!strncmp(str, "nopanic", 7))
+ hardlockup_panic = 0;
+ else if (!strncmp(str, "0", 1))
+ watchdog_enabled = 0;
+ return 1;
+}
+__setup("nmi_watchdog=", hardlockup_panic_setup);
+#endif
+
+unsigned int __read_mostly softlockup_panic =
+ CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
+
+static int __init softlockup_panic_setup(char *str)
+{
+ softlockup_panic = simple_strtoul(str, NULL, 0);
+
+ return 1;
+}
+__setup("softlockup_panic=", softlockup_panic_setup);
+
+static int __init nowatchdog_setup(char *str)
+{
+ watchdog_enabled = 0;
+ return 1;
+}
+__setup("nowatchdog", nowatchdog_setup);
+
+/* deprecated */
+static int __init nosoftlockup_setup(char *str)
+{
+ watchdog_enabled = 0;
+ return 1;
+}
+__setup("nosoftlockup", nosoftlockup_setup);
+/* */
+
+/*
+ * Hard-lockup warnings should be triggered after just a few seconds. Soft-
+ * lockups can have false positives under extreme conditions. So we generally
+ * want a higher threshold for soft lockups than for hard lockups. So we couple
+ * the thresholds with a factor: we make the soft threshold twice the amount of
+ * time the hard threshold is.
+ */
+static int get_softlockup_thresh(void)
+{
+ return watchdog_thresh * 2;
+}
+
+/*
+ * Returns seconds, approximately. We don't need nanosecond
+ * resolution, and we don't need to waste time with a big divide when
+ * 2^30ns == 1.074s.
+ */
+static unsigned long get_timestamp(int this_cpu)
+{
+ return cpu_clock(this_cpu) >> 30LL; /* 2^30 ~= 10^9 */
+}
+
+static u64 get_sample_period(void)
+{
+ /*
+ * convert watchdog_thresh from seconds to ns
+ * the divide by 5 is to give hrtimer several chances (two
+ * or three with the current relation between the soft
+ * and hard thresholds) to increment before the
+ * hardlockup detector generates a warning
+ */
+ return get_softlockup_thresh() * ((u64)NSEC_PER_SEC / 5);
+}
+
+/* Commands for resetting the watchdog */
+static void __touch_watchdog(void)
+{
+ int this_cpu = smp_processor_id();
+
+ __this_cpu_write(watchdog_touch_ts, get_timestamp(this_cpu));
+}
+
+void touch_softlockup_watchdog(void)
+{
+ __this_cpu_write(watchdog_touch_ts, 0);
+}
+EXPORT_SYMBOL(touch_softlockup_watchdog);
+
+void touch_all_softlockup_watchdogs(void)
+{
+ int cpu;
+
+ /*
+ * this is done lockless
+ * do we care if a 0 races with a timestamp?
+ * all it means is the softlock check starts one cycle later
+ */
+ for_each_online_cpu(cpu)
+ per_cpu(watchdog_touch_ts, cpu) = 0;
+}
+
+#ifdef CONFIG_HARDLOCKUP_DETECTOR
+void touch_nmi_watchdog(void)
+{
+ if (watchdog_enabled) {
+ unsigned cpu;
+
+ for_each_present_cpu(cpu) {
+ if (per_cpu(watchdog_nmi_touch, cpu) != true)
+ per_cpu(watchdog_nmi_touch, cpu) = true;
+ }
+ }
+ touch_softlockup_watchdog();
+}
+EXPORT_SYMBOL(touch_nmi_watchdog);
+
+#endif
+
+void touch_softlockup_watchdog_sync(void)
+{
+ __raw_get_cpu_var(softlockup_touch_sync) = true;
+ __raw_get_cpu_var(watchdog_touch_ts) = 0;
+}
+
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_NMI
+/* watchdog detector functions */
+static int is_hardlockup(void)
+{
+ unsigned long hrint = __this_cpu_read(hrtimer_interrupts);
+
+ if (__this_cpu_read(hrtimer_interrupts_saved) == hrint)
+ return 1;
+
+ __this_cpu_write(hrtimer_interrupts_saved, hrint);
+ return 0;
+}
+#endif
+
+static int is_softlockup(unsigned long touch_ts)
+{
+ unsigned long now = get_timestamp(smp_processor_id());
+
+ /* Warn about unreasonable delays: */
+ if (time_after(now, touch_ts + get_softlockup_thresh()))
+ return now - touch_ts;
+
+ return 0;
+}
+
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_NMI
+
+static DEFINE_RAW_SPINLOCK(watchdog_output_lock);
+
+static struct perf_event_attr wd_hw_attr = {
+ .type = PERF_TYPE_HARDWARE,
+ .config = PERF_COUNT_HW_CPU_CYCLES,
+ .size = sizeof(struct perf_event_attr),
+ .pinned = 1,
+ .disabled = 1,
+};
+
+/* Callback function for perf event subsystem */
+static void watchdog_overflow_callback(struct perf_event *event,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ /* Ensure the watchdog never gets throttled */
+ event->hw.interrupts = 0;
+
+ if (__this_cpu_read(watchdog_nmi_touch) == true) {
+ __this_cpu_write(watchdog_nmi_touch, false);
+ return;
+ }
+
+ /* check for a hardlockup
+ * This is done by making sure our timer interrupt
+ * is incrementing. The timer interrupt should have
+ * fired multiple times before we overflow'd. If it hasn't
+ * then this is a good indication the cpu is stuck
+ */
+ if (is_hardlockup()) {
+ int this_cpu = smp_processor_id();
+
+ /* only print hardlockups once */
+ if (__this_cpu_read(hard_watchdog_warn) == true)
+ return;
+
+ /*
+ * If early-printk is enabled then make sure we do not
+ * lock up in printk() and kill console logging:
+ */
+ printk_kill();
+
+ if (hardlockup_panic) {
+ panic("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
+ } else {
+ raw_spin_lock(&watchdog_output_lock);
+ WARN(1, "Watchdog detected hard LOCKUP on cpu %d", this_cpu);
+ raw_spin_unlock(&watchdog_output_lock);
+ }
+
+ __this_cpu_write(hard_watchdog_warn, true);
+ return;
+ }
+
+ __this_cpu_write(hard_watchdog_warn, false);
+ return;
+}
+#endif
+
+#ifdef CONFIG_HARDLOCKUP_DETECTOR
+static void watchdog_interrupt_count(void)
+{
+ __this_cpu_inc(hrtimer_interrupts);
+}
+#else
+static inline void watchdog_interrupt_count(void) { return; }
+#endif /* CONFIG_HARDLOCKUP_DETECTOR */
+
+/* watchdog kicker functions */
+static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
+{
+ unsigned long touch_ts = __this_cpu_read(watchdog_touch_ts);
+ struct pt_regs *regs = get_irq_regs();
+ int duration;
+
+ /* kick the hardlockup detector */
+ watchdog_interrupt_count();
+
+ /* kick the softlockup detector */
+ wake_up_process(__this_cpu_read(softlockup_watchdog));
+
+ /* .. and repeat */
+ hrtimer_forward_now(hrtimer, ns_to_ktime(get_sample_period()));
+
+ if (touch_ts == 0) {
+ if (unlikely(__this_cpu_read(softlockup_touch_sync))) {
+ /*
+ * If the time stamp was touched atomically
+ * make sure the scheduler tick is up to date.
+ */
+ __this_cpu_write(softlockup_touch_sync, false);
+ sched_clock_tick();
+ }
+ __touch_watchdog();
+ return HRTIMER_RESTART;
+ }
+
+ /* check for a softlockup
+ * This is done by making sure a high priority task is
+ * being scheduled. The task touches the watchdog to
+ * indicate it is getting cpu time. If it hasn't then
+ * this is a good indication some task is hogging the cpu
+ */
+ duration = is_softlockup(touch_ts);
+ if (unlikely(duration)) {
+ /* only warn once */
+ if (__this_cpu_read(soft_watchdog_warn) == true)
+ return HRTIMER_RESTART;
+
+ printk(KERN_EMERG "BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n",
+ smp_processor_id(), duration,
+ current->comm, task_pid_nr(current));
+ print_modules();
+ print_irqtrace_events(current);
+ if (regs)
+ show_regs(regs);
+ else
+ dump_stack();
+
+ if (softlockup_panic)
+ panic("softlockup: hung tasks");
+ __this_cpu_write(soft_watchdog_warn, true);
+ } else
+ __this_cpu_write(soft_watchdog_warn, false);
+
+ return HRTIMER_RESTART;
+}
+
+
+/*
+ * The watchdog thread - touches the timestamp.
+ */
+static int watchdog(void *unused)
+{
+ struct sched_param param = { .sched_priority = 0 };
+ struct hrtimer *hrtimer = &__raw_get_cpu_var(watchdog_hrtimer);
+
+ /* initialize timestamp */
+ __touch_watchdog();
+
+ /* kick off the timer for the hardlockup detector */
+ /* done here because hrtimer_start can only pin to smp_processor_id() */
+ hrtimer_start(hrtimer, ns_to_ktime(get_sample_period()),
+ HRTIMER_MODE_REL_PINNED);
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ /*
+ * Run briefly (kicked by the hrtimer callback function) once every
+ * get_sample_period() seconds (4 seconds by default) to reset the
+ * softlockup timestamp. If this gets delayed for more than
+ * 2*watchdog_thresh seconds then the debug-printout triggers in
+ * watchdog_timer_fn().
+ */
+ while (!kthread_should_stop()) {
+ __touch_watchdog();
+ schedule();
+
+ if (kthread_should_stop())
+ break;
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ }
+ /*
+ * Drop the policy/priority elevation during thread exit to avoid a
+ * scheduling latency spike.
+ */
+ __set_current_state(TASK_RUNNING);
+ sched_setscheduler(current, SCHED_NORMAL, ¶m);
+ return 0;
+}
+
+
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_NMI
+static int watchdog_nmi_enable(int cpu)
+{
+ struct perf_event_attr *wd_attr;
+ struct perf_event *event = per_cpu(watchdog_ev, cpu);
+
+ /* is it already setup and enabled? */
+ if (event && event->state > PERF_EVENT_STATE_OFF)
+ goto out;
+
+ /* it is setup but not enabled */
+ if (event != NULL)
+ goto out_enable;
+
+ wd_attr = &wd_hw_attr;
+ wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh);
+
+ /* Try to register using hardware perf events */
+ event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
+ if (!IS_ERR(event)) {
+ pr_info("enabled, takes one hw-pmu counter.\n");
+ goto out_save;
+ }
+
+
+ /* vary the KERN level based on the returned errno */
+ if (PTR_ERR(event) == -EOPNOTSUPP)
+ pr_info("disabled (cpu%i): not supported (no LAPIC?)\n", cpu);
+ else if (PTR_ERR(event) == -ENOENT)
+ pr_warning("disabled (cpu%i): hardware events not enabled\n",
+ cpu);
+ else
+ pr_err("disabled (cpu%i): unable to create perf event: %ld\n",
+ cpu, PTR_ERR(event));
+ return PTR_ERR(event);
+
+ /* success path */
+out_save:
+ per_cpu(watchdog_ev, cpu) = event;
+out_enable:
+ perf_event_enable(per_cpu(watchdog_ev, cpu));
+out:
+ return 0;
+}
+
+static void watchdog_nmi_disable(int cpu)
+{
+ struct perf_event *event = per_cpu(watchdog_ev, cpu);
+
+ if (event) {
+ perf_event_disable(event);
+ per_cpu(watchdog_ev, cpu) = NULL;
+
+ /* should be in cleanup, but blocks oprofile */
+ perf_event_release_kernel(event);
+ }
+ return;
+}
+#else
+static int watchdog_nmi_enable(int cpu) { return 0; }
+static void watchdog_nmi_disable(int cpu) { return; }
+#endif /* CONFIG_HARDLOCKUP_DETECTOR */
+
+/* prepare/enable/disable routines */
+static void watchdog_prepare_cpu(int cpu)
+{
+ struct hrtimer *hrtimer = &per_cpu(watchdog_hrtimer, cpu);
+
+ WARN_ON(per_cpu(softlockup_watchdog, cpu));
+ hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer->function = watchdog_timer_fn;
+
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_OTHER_CPU
+ per_cpu(watchdog_nmi_touch, cpu) = true;
+#endif
+}
+
+static int watchdog_enable(int cpu)
+{
+ struct task_struct *p = per_cpu(softlockup_watchdog, cpu);
+ int err = 0;
+
+ /* enable the perf event */
+ err = watchdog_nmi_enable(cpu);
+
+ /* Regardless of err above, fall through and start softlockup */
+
+ /* create the watchdog thread */
+ if (!p) {
+ struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
+ p = kthread_create_on_node(watchdog, NULL, cpu_to_node(cpu), "watchdog/%d", cpu);
+ if (IS_ERR(p)) {
+ pr_err("softlockup watchdog for %i failed\n", cpu);
+ if (!err) {
+ /* if hardlockup hasn't already set this */
+ err = PTR_ERR(p);
+ /* and disable the perf event */
+ watchdog_nmi_disable(cpu);
+ }
+ goto out;
+ }
+ sched_setscheduler(p, SCHED_FIFO, ¶m);
+ kthread_bind(p, cpu);
+ per_cpu(watchdog_touch_ts, cpu) = 0;
+ per_cpu(softlockup_watchdog, cpu) = p;
+ wake_up_process(p);
+ }
+
+out:
+ return err;
+}
+
+static void watchdog_disable(int cpu)
+{
+ struct task_struct *p = per_cpu(softlockup_watchdog, cpu);
+ struct hrtimer *hrtimer = &per_cpu(watchdog_hrtimer, cpu);
+
+ /*
+ * cancel the timer first to stop incrementing the stats
+ * and waking up the kthread
+ */
+ hrtimer_cancel(hrtimer);
+
+ /* disable the perf event */
+ watchdog_nmi_disable(cpu);
+
+ /* stop the watchdog thread */
+ if (p) {
+ per_cpu(softlockup_watchdog, cpu) = NULL;
+ kthread_stop(p);
+ }
+}
+
+/* sysctl functions */
+#ifdef CONFIG_SYSCTL
+static void watchdog_enable_all_cpus(void)
+{
+ int cpu;
+
+ watchdog_enabled = 0;
+
+ for_each_online_cpu(cpu)
+ if (!watchdog_enable(cpu))
+ /* if any cpu succeeds, watchdog is considered
+ enabled for the system */
+ watchdog_enabled = 1;
+
+ if (!watchdog_enabled)
+ pr_err("failed to be enabled on some cpus\n");
+
+}
+
+static void watchdog_disable_all_cpus(void)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu)
+ watchdog_disable(cpu);
+
+ /* if all watchdogs are disabled, then they are disabled for the system */
+ watchdog_enabled = 0;
+}
+
+
+/*
+ * proc handler for /proc/sys/kernel/nmi_watchdog,watchdog_thresh
+ */
+
+int proc_dowatchdog(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ int ret;
+
+ ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+ if (ret || !write)
+ goto out;
+
+ if (watchdog_enabled && watchdog_thresh)
+ watchdog_enable_all_cpus();
+ else
+ watchdog_disable_all_cpus();
+
+out:
+ return ret;
+}
+#endif /* CONFIG_SYSCTL */
+
+
+/*
+ * Create/destroy watchdog threads as CPUs come and go:
+ */
+static int __cpuinit
+cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+ int hotcpu = (unsigned long)hcpu;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
+ watchdog_prepare_cpu(hotcpu);
+ break;
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ if (watchdog_enabled)
+ watchdog_enable(hotcpu);
+ break;
+#ifdef CONFIG_HOTPLUG_CPU
+ case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
+ watchdog_disable(hotcpu);
+ break;
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ watchdog_disable(hotcpu);
+ break;
+#endif /* CONFIG_HOTPLUG_CPU */
+ }
+
+ /*
+ * hardlockup and softlockup are not important enough
+ * to block cpu bring up. Just always succeed and
+ * rely on printk output to flag problems.
+ */
+ return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata cpu_nfb = {
+ .notifier_call = cpu_callback
+};
+
+void __init lockup_detector_init(void)
+{
+ void *cpu = (void *)(long)smp_processor_id();
+ int err;
+
+ err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu);
+ WARN_ON(notifier_to_errno(err));
+
+ cpu_callback(&cpu_nfb, CPU_ONLINE, cpu);
+ register_cpu_notifier(&cpu_nfb);
+
+ return;
+}