static int k3_r5_rproc_stop(struct rproc *rproc)
{
        struct k3_r5_rproc *kproc = rproc->priv;
        struct k3_r5_cluster *cluster = kproc->cluster;
        struct device *dev = kproc->dev;
        struct k3_r5_core *core1, *core = kproc->core;
        int ret;


        if (cluster->mode != CLUSTER_MODE_LOCKSTEP) {
                /* do not allow core 0 to stop before core 1 */
                core1 = list_last_entry(&cluster->cores, struct k3_r5_core,
                                        elem);
                if (core != core1 && core1->rproc->state != RPROC_OFFLINE &&
                    core1->rproc->state != RPROC_SUSPENDED) {
                        dev_err(dev, "%s: can not stop core 0 before core 1\n",
                                __func__);
                        ret = -EPERM;
                        goto out;
                }
        }

        /* halt all applicable cores */
        if (cluster->mode == CLUSTER_MODE_LOCKSTEP) {
                list_for_each_entry(core, &cluster->cores, elem) {
                        ret = k3_r5_core_halt(core);
                        if (ret) {
                                core = list_prev_entry(core, elem);
                                goto unroll_core_halt;
                        }
                }
        } else {

                ret = k3_r5_core_halt(core);
                if (ret)
                        goto out;
        }

        mbox_free_channel(kproc->mbox);

        return 0;

unroll_core_halt:
        list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
                if (k3_r5_core_run(core))
                        dev_warn(core->dev, "core run back failed\n");
        }
out:
        return ret;
}