// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020, Intel Corporation. */

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

#include "igc.h"
#include "igc_xdp.h"

int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
                     struct netlink_ext_ack *extack)
{
        struct net_device *dev = adapter->netdev;
        bool if_running = netif_running(dev);
        struct bpf_prog *old_prog;
        bool need_update;
        unsigned int i;

        if (dev->mtu > ETH_DATA_LEN) {
                /* For now, the driver doesn't support XDP functionality with
                 * jumbo frames so we return error.
                 */
                NL_SET_ERR_MSG_MOD(extack, "Jumbo frames not supported");
                return -EOPNOTSUPP;
        }

        need_update = !!adapter->xdp_prog != !!prog;
        if (if_running && need_update) {
                for (i = 0; i < adapter->num_rx_queues; i++) {
                        igc_disable_rx_ring(adapter->rx_ring[i]);
                        igc_disable_tx_ring(adapter->tx_ring[i]);
                        napi_disable(&adapter->rx_ring[i]->q_vector->napi);
                }
        }

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

        if (prog)
                xdp_features_set_redirect_target(dev, true);
        else
                xdp_features_clear_redirect_target(dev);

        if (if_running && need_update) {
                for (i = 0; i < adapter->num_rx_queues; i++) {
                        napi_enable(&adapter->rx_ring[i]->q_vector->napi);
                        igc_enable_tx_ring(adapter->tx_ring[i]);
                        igc_enable_rx_ring(adapter->rx_ring[i]);
                }
        }

        return 0;
}

static int igc_xdp_enable_pool(struct igc_adapter *adapter,
                               struct xsk_buff_pool *pool, u16 queue_id)
{
        struct net_device *ndev = adapter->netdev;
        struct device *dev = &adapter->pdev->dev;
        struct igc_ring *rx_ring, *tx_ring;
        struct napi_struct *napi;
        bool needs_reset;
        u32 frame_size;
        int err;

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

        frame_size = xsk_pool_get_rx_frame_size(pool);
        if (frame_size < ETH_FRAME_LEN + VLAN_HLEN * 2) {
                /* When XDP is enabled, the driver doesn't support frames that
                 * span over multiple buffers. To avoid that, we check if xsk
                 * frame size is big enough to fit the max ethernet frame size
                 * + vlan double tagging.
                 */
                return -EOPNOTSUPP;
        }

        err = xsk_pool_dma_map(pool, dev, IGC_RX_DMA_ATTR);
        if (err) {
                netdev_err(ndev, "Failed to map xsk pool\n");
                return err;
        }

        needs_reset = netif_running(adapter->netdev) && igc_xdp_is_enabled(adapter);

        rx_ring = adapter->rx_ring[queue_id];
        tx_ring = adapter->tx_ring[queue_id];
        /* Rx and Tx rings share the same napi context. */
        napi = &rx_ring->q_vector->napi;

        if (needs_reset) {
                igc_disable_rx_ring(rx_ring);
                igc_disable_tx_ring(tx_ring);
                napi_disable(napi);
        }

        set_bit(IGC_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
        set_bit(IGC_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);

        if (needs_reset) {
                napi_enable(napi);
                igc_enable_rx_ring(rx_ring);
                igc_enable_tx_ring(tx_ring);

                err = igc_xsk_wakeup(ndev, queue_id, XDP_WAKEUP_RX);
                if (err) {
                        xsk_pool_dma_unmap(pool, IGC_RX_DMA_ATTR);
                        return err;
                }
        }

        return 0;
}

static int igc_xdp_disable_pool(struct igc_adapter *adapter, u16 queue_id)
{
        struct igc_ring *rx_ring, *tx_ring;
        struct xsk_buff_pool *pool;
        struct napi_struct *napi;
        bool needs_reset;

        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;

        needs_reset = netif_running(adapter->netdev) && igc_xdp_is_enabled(adapter);

        rx_ring = adapter->rx_ring[queue_id];
        tx_ring = adapter->tx_ring[queue_id];
        /* Rx and Tx rings share the same napi context. */
        napi = &rx_ring->q_vector->napi;

        if (needs_reset) {
                igc_disable_rx_ring(rx_ring);
                igc_disable_tx_ring(tx_ring);
                napi_disable(napi);
        }

        xsk_pool_dma_unmap(pool, IGC_RX_DMA_ATTR);
        clear_bit(IGC_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
        clear_bit(IGC_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);

        if (needs_reset) {
                napi_enable(napi);
                igc_enable_rx_ring(rx_ring);
                igc_enable_tx_ring(tx_ring);
        }

        return 0;
}

int igc_xdp_setup_pool(struct igc_adapter *adapter, struct xsk_buff_pool *pool,
                       u16 queue_id)
{
        return pool ? igc_xdp_enable_pool(adapter, pool, queue_id) :
                      igc_xdp_disable_pool(adapter, queue_id);
}