// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2022 Gerhard Engleder <gerhard@engleder-embedded.com> */

#include <linux/if_vlan.h>
#include <net/xdp_sock_drv.h>

#include "tsnep.h"

int tsnep_xdp_setup_prog(struct tsnep_adapter *adapter, struct bpf_prog *prog,
                         struct netlink_ext_ack *extack)
{
        struct bpf_prog *old_prog;

        old_prog = xchg(&adapter->xdp_prog, prog);
        if (old_prog)
                bpf_prog_put(old_prog);

        return 0;
}

static int tsnep_xdp_enable_pool(struct tsnep_adapter *adapter,
                                 struct xsk_buff_pool *pool, u16 queue_id)
{
        struct tsnep_queue *queue;
        int retval;

        if (queue_id >= adapter->num_rx_queues ||
            queue_id >= adapter->num_tx_queues)
                return -EINVAL;

        queue = &adapter->queue[queue_id];
        if (queue->rx->queue_index != queue_id ||
            queue->tx->queue_index != queue_id) {
                netdev_err(adapter->netdev,
                           "XSK support only for TX/RX queue pairs\n");

                return -EOPNOTSUPP;
        }

        retval = xsk_pool_dma_map(pool, adapter->dmadev,
                                  DMA_ATTR_SKIP_CPU_SYNC);
        if (retval) {
                netdev_err(adapter->netdev, "failed to map XSK pool\n");

                return retval;
        }

        retval = tsnep_enable_xsk(queue, pool);
        if (retval) {
                xsk_pool_dma_unmap(pool, DMA_ATTR_SKIP_CPU_SYNC);

                return retval;
        }

        return 0;
}

static int tsnep_xdp_disable_pool(struct tsnep_adapter *adapter, u16 queue_id)
{
        struct xsk_buff_pool *pool;
        struct tsnep_queue *queue;

        if (queue_id >= adapter->num_rx_queues ||
            queue_id >= adapter->num_tx_queues)
                return -EINVAL;

        pool = xsk_get_pool_from_qid(adapter->netdev, queue_id);
        if (!pool)
                return -EINVAL;

        queue = &adapter->queue[queue_id];

        tsnep_disable_xsk(queue);

        xsk_pool_dma_unmap(pool, DMA_ATTR_SKIP_CPU_SYNC);

        return 0;
}

int tsnep_xdp_setup_pool(struct tsnep_adapter *adapter,
                         struct xsk_buff_pool *pool, u16 queue_id)
{
        return pool ? tsnep_xdp_enable_pool(adapter, pool, queue_id) :
                      tsnep_xdp_disable_pool(adapter, queue_id);
}