// SPDX-License-Identifier: GPL-2.0
#include <linux/ftrace.h>
#include <linux/tracepoint.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/rv.h>
#include <rv/instrumentation.h>

#define MODULE_NAME "sssw"

#include <trace/events/sched.h>
#include <trace/events/signal.h>
#include <rv_trace.h>
#include <monitors/sched/sched.h>

#define RV_MON_TYPE RV_MON_PER_TASK
#include "sssw.h"
#include <rv/da_monitor.h>

static void handle_sched_set_state(void *data, struct task_struct *tsk, int state)
{
        if (state == TASK_RUNNING)
                da_handle_start_event(tsk, sched_set_state_runnable_sssw);
        else
                da_handle_event(tsk, sched_set_state_sleepable_sssw);
}

static void handle_sched_switch(void *data, bool preempt,
                                struct task_struct *prev,
                                struct task_struct *next,
                                unsigned int prev_state)
{
        if (preempt)
                da_handle_event(prev, sched_switch_preempt_sssw);
        else if (prev_state == TASK_RUNNING)
                da_handle_event(prev, sched_switch_yield_sssw);
        else if (prev_state == TASK_RTLOCK_WAIT)
                /* special case of sleeping task with racy conditions */
                da_handle_event(prev, sched_switch_blocking_sssw);
        else
                da_handle_event(prev, sched_switch_suspend_sssw);
        da_handle_event(next, sched_switch_in_sssw);
}

static void handle_sched_wakeup(void *data, struct task_struct *p)
{
        /*
         * Wakeup can also lead to signal_wakeup although the system is
         * actually runnable. The monitor can safely start with this event.
         */
        da_handle_start_event(p, sched_wakeup_sssw);
}

static void handle_signal_deliver(void *data, int sig,
                                   struct kernel_siginfo *info,
                                   struct k_sigaction *ka)
{
        da_handle_event(current, signal_deliver_sssw);
}

static int enable_sssw(void)
{
        int retval;

        retval = da_monitor_init();
        if (retval)
                return retval;

        rv_attach_trace_probe("sssw", sched_set_state_tp, handle_sched_set_state);
        rv_attach_trace_probe("sssw", sched_switch, handle_sched_switch);
        rv_attach_trace_probe("sssw", sched_wakeup, handle_sched_wakeup);
        rv_attach_trace_probe("sssw", signal_deliver, handle_signal_deliver);

        return 0;
}

static void disable_sssw(void)
{
        rv_this.enabled = 0;

        rv_detach_trace_probe("sssw", sched_set_state_tp, handle_sched_set_state);
        rv_detach_trace_probe("sssw", sched_switch, handle_sched_switch);
        rv_detach_trace_probe("sssw", sched_wakeup, handle_sched_wakeup);
        rv_detach_trace_probe("sssw", signal_deliver, handle_signal_deliver);

        da_monitor_destroy();
}

static struct rv_monitor rv_this = {
        .name = "sssw",
        .description = "set state sleep and wakeup.",
        .enable = enable_sssw,
        .disable = disable_sssw,
        .reset = da_monitor_reset_all,
        .enabled = 0,
};

static int __init register_sssw(void)
{
        return rv_register_monitor(&rv_this, &rv_sched);
}

static void __exit unregister_sssw(void)
{
        rv_unregister_monitor(&rv_this);
}

module_init(register_sssw);
module_exit(unregister_sssw);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Gabriele Monaco <gmonaco@redhat.com>");
MODULE_DESCRIPTION("sssw: set state sleep and wakeup.");