// 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 "sts"

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

#define RV_MON_TYPE RV_MON_PER_CPU
#include "sts.h"
#include <rv/da_monitor.h>

#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/trace/irq_vectors.h>

static void handle_vector_irq_entry(void *data, int vector)
{
        da_handle_event(irq_entry_sts);
}

static void attach_vector_irq(void)
{
        rv_attach_trace_probe("sts", local_timer_entry, handle_vector_irq_entry);
        if (IS_ENABLED(CONFIG_IRQ_WORK))
                rv_attach_trace_probe("sts", irq_work_entry, handle_vector_irq_entry);
        if (IS_ENABLED(CONFIG_SMP)) {
                rv_attach_trace_probe("sts", reschedule_entry, handle_vector_irq_entry);
                rv_attach_trace_probe("sts", call_function_entry, handle_vector_irq_entry);
                rv_attach_trace_probe("sts", call_function_single_entry, handle_vector_irq_entry);
        }
}

static void detach_vector_irq(void)
{
        rv_detach_trace_probe("sts", local_timer_entry, handle_vector_irq_entry);
        if (IS_ENABLED(CONFIG_IRQ_WORK))
                rv_detach_trace_probe("sts", irq_work_entry, handle_vector_irq_entry);
        if (IS_ENABLED(CONFIG_SMP)) {
                rv_detach_trace_probe("sts", reschedule_entry, handle_vector_irq_entry);
                rv_detach_trace_probe("sts", call_function_entry, handle_vector_irq_entry);
                rv_detach_trace_probe("sts", call_function_single_entry, handle_vector_irq_entry);
        }
}

#else
/* We assume irq_entry tracepoints are sufficient on other architectures */
static void attach_vector_irq(void) { }
static void detach_vector_irq(void) { }
#endif

static void handle_irq_disable(void *data, unsigned long ip, unsigned long parent_ip)
{
        da_handle_event(irq_disable_sts);
}

static void handle_irq_enable(void *data, unsigned long ip, unsigned long parent_ip)
{
        da_handle_event(irq_enable_sts);
}

static void handle_irq_entry(void *data, int irq, struct irqaction *action)
{
        da_handle_event(irq_entry_sts);
}

static void handle_sched_switch(void *data, bool preempt,
                                struct task_struct *prev,
                                struct task_struct *next,
                                unsigned int prev_state)
{
        da_handle_event(sched_switch_sts);
}

static void handle_schedule_entry(void *data, bool preempt)
{
        da_handle_event(schedule_entry_sts);
}

static void handle_schedule_exit(void *data, bool is_switch)
{
        da_handle_start_event(schedule_exit_sts);
}

static int enable_sts(void)
{
        int retval;

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

        rv_attach_trace_probe("sts", irq_disable, handle_irq_disable);
        rv_attach_trace_probe("sts", irq_enable, handle_irq_enable);
        rv_attach_trace_probe("sts", irq_handler_entry, handle_irq_entry);
        rv_attach_trace_probe("sts", sched_switch, handle_sched_switch);
        rv_attach_trace_probe("sts", sched_entry_tp, handle_schedule_entry);
        rv_attach_trace_probe("sts", sched_exit_tp, handle_schedule_exit);
        attach_vector_irq();

        return 0;
}

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

        rv_detach_trace_probe("sts", irq_disable, handle_irq_disable);
        rv_detach_trace_probe("sts", irq_enable, handle_irq_enable);
        rv_detach_trace_probe("sts", irq_handler_entry, handle_irq_entry);
        rv_detach_trace_probe("sts", sched_switch, handle_sched_switch);
        rv_detach_trace_probe("sts", sched_entry_tp, handle_schedule_entry);
        rv_detach_trace_probe("sts", sched_exit_tp, handle_schedule_exit);
        detach_vector_irq();

        da_monitor_destroy();
}

/*
 * This is the monitor register section.
 */
static struct rv_monitor rv_this = {
        .name = "sts",
        .description = "schedule implies task switch.",
        .enable = enable_sts,
        .disable = disable_sts,
        .reset = da_monitor_reset_all,
        .enabled = 0,
};

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

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

module_init(register_sts);
module_exit(unregister_sts);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Gabriele Monaco <gmonaco@redhat.com>");
MODULE_DESCRIPTION("sts: schedule implies task switch.");