// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
 * Copyright (c) 2023 David Vernet <dvernet@meta.com>
 * Copyright (c) 2023 Tejun Heo <tj@kernel.org>
 */
#include <bpf/bpf.h>
#include <scx/common.h>
#include <sys/wait.h>
#include <unistd.h>
#include "enq_select_cpu.bpf.skel.h"
#include "scx_test.h"

static enum scx_test_status setup(void **ctx)
{
        struct enq_select_cpu *skel;

        skel = enq_select_cpu__open();
        SCX_FAIL_IF(!skel, "Failed to open");
        SCX_ENUM_INIT(skel);
        SCX_FAIL_IF(enq_select_cpu__load(skel), "Failed to load skel");

        *ctx = skel;

        return SCX_TEST_PASS;
}

static int test_select_cpu_from_user(const struct enq_select_cpu *skel)
{
        int fd, ret;
        __u64 args[1];

        LIBBPF_OPTS(bpf_test_run_opts, attr,
                .ctx_in = args,
                .ctx_size_in = sizeof(args),
        );

        args[0] = getpid();
        fd = bpf_program__fd(skel->progs.select_cpu_from_user);
        if (fd < 0)
                return fd;

        ret = bpf_prog_test_run_opts(fd, &attr);
        if (ret < 0)
                return ret;

        fprintf(stderr, "%s: CPU %d\n", __func__, attr.retval);

        return 0;
}

static enum scx_test_status run(void *ctx)
{
        struct enq_select_cpu *skel = ctx;
        struct bpf_link *link;

        link = bpf_map__attach_struct_ops(skel->maps.enq_select_cpu_ops);
        if (!link) {
                SCX_ERR("Failed to attach scheduler");
                return SCX_TEST_FAIL;
        }

        /* Pick an idle CPU from user-space */
        SCX_FAIL_IF(test_select_cpu_from_user(skel), "Failed to pick idle CPU");

        sleep(1);

        SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_NONE));
        bpf_link__destroy(link);

        return SCX_TEST_PASS;
}

static void cleanup(void *ctx)
{
        struct enq_select_cpu *skel = ctx;

        enq_select_cpu__destroy(skel);
}

struct scx_test enq_select_cpu = {
        .name = "enq_select_cpu",
        .description = "Verify scx_bpf_select_cpu_dfl() from multiple contexts",
        .setup = setup,
        .run = run,
        .cleanup = cleanup,
};
REGISTER_SCX_TEST(&enq_select_cpu)