/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2024 Meta Platforms, Inc. and affiliates.
 * Copyright (c) 2024 David Vernet <dvernet@meta.com>
 */

#include <scx/common.bpf.h>

char _license[] SEC("license") = "GPL";

#include "exit_test.h"

const volatile int exit_point;
UEI_DEFINE(uei);

#define EXIT_CLEANLY() scx_bpf_exit(exit_point, "%d", exit_point)

#define DSQ_ID 0

s32 BPF_STRUCT_OPS(exit_select_cpu, struct task_struct *p,
                   s32 prev_cpu, u64 wake_flags)
{
        bool found;

        if (exit_point == EXIT_SELECT_CPU)
                EXIT_CLEANLY();

        return scx_bpf_select_cpu_dfl(p, prev_cpu, wake_flags, &found);
}

void BPF_STRUCT_OPS(exit_enqueue, struct task_struct *p, u64 enq_flags)
{
        if (exit_point == EXIT_ENQUEUE)
                EXIT_CLEANLY();

        scx_bpf_dsq_insert(p, DSQ_ID, SCX_SLICE_DFL, enq_flags);
}

void BPF_STRUCT_OPS(exit_dispatch, s32 cpu, struct task_struct *p)
{
        if (exit_point == EXIT_DISPATCH)
                EXIT_CLEANLY();

        scx_bpf_dsq_move_to_local(DSQ_ID);
}

void BPF_STRUCT_OPS(exit_enable, struct task_struct *p)
{
        if (exit_point == EXIT_ENABLE)
                EXIT_CLEANLY();
}

s32 BPF_STRUCT_OPS(exit_init_task, struct task_struct *p,
                    struct scx_init_task_args *args)
{
        if (exit_point == EXIT_INIT_TASK)
                EXIT_CLEANLY();

        return 0;
}

void BPF_STRUCT_OPS(exit_exit, struct scx_exit_info *ei)
{
        UEI_RECORD(uei, ei);
}

s32 BPF_STRUCT_OPS_SLEEPABLE(exit_init)
{
        if (exit_point == EXIT_INIT)
                EXIT_CLEANLY();

        return scx_bpf_create_dsq(DSQ_ID, -1);
}

SEC(".struct_ops.link")
struct sched_ext_ops exit_ops = {
        .select_cpu             = (void *) exit_select_cpu,
        .enqueue                = (void *) exit_enqueue,
        .dispatch               = (void *) exit_dispatch,
        .init_task              = (void *) exit_init_task,
        .enable                 = (void *) exit_enable,
        .exit                   = (void *) exit_exit,
        .init                   = (void *) exit_init,
        .name                   = "exit",
        .timeout_ms             = 1000U,
};