// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2025 Andrea Righi <arighi@nvidia.com>
 */
#include <bpf/bpf.h>
#include <scx/common.h>
#include <sys/wait.h>
#include <unistd.h>
#include "allowed_cpus.bpf.skel.h"
#include "scx_test.h"

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

        skel = allowed_cpus__open();
        SCX_FAIL_IF(!skel, "Failed to open");
        SCX_ENUM_INIT(skel);
        SCX_FAIL_IF(allowed_cpus__load(skel), "Failed to load skel");

        *ctx = skel;

        return SCX_TEST_PASS;
}

static int test_select_cpu_from_user(const struct allowed_cpus *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 allowed_cpus *skel = ctx;
        struct bpf_link *link;

        link = bpf_map__attach_struct_ops(skel->maps.allowed_cpus_ops);
        SCX_FAIL_IF(!link, "Failed to attach scheduler");

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

        /* Just sleeping is fine, plenty of scheduling events happening */
        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 allowed_cpus *skel = ctx;

        allowed_cpus__destroy(skel);
}

struct scx_test allowed_cpus = {
        .name = "allowed_cpus",
        .description = "Verify scx_bpf_select_cpu_and()",
        .setup = setup,
        .run = run,
        .cleanup = cleanup,
};
REGISTER_SCX_TEST(&allowed_cpus)