Add basic AF_XDP support without zero-copy Signed-off-by: Ilias Apalodimas <ilias.apalodi...@linaro.org> --- drivers/net/ethernet/socionext/netsec.c | 211 ++++++++++++++++++++++++++++++-- 1 file changed, 202 insertions(+), 9 deletions(-)
diff --git a/drivers/net/ethernet/socionext/netsec.c b/drivers/net/ethernet/socionext/netsec.c index 666fee2..7464ca6 100644 --- a/drivers/net/ethernet/socionext/netsec.c +++ b/drivers/net/ethernet/socionext/netsec.c @@ -9,6 +9,8 @@ #include <linux/etherdevice.h> #include <linux/interrupt.h> #include <linux/io.h> +#include <linux/bpf.h> +#include <linux/bpf_trace.h> #include <net/tcp.h> #include <net/ip6_checksum.h> @@ -238,6 +240,11 @@ #define NETSEC_F_NETSEC_VER_MAJOR_NUM(x) ((x) & 0xffff0000) +#define NETSEC_XDP_PASS 0 +#define NETSEC_XDP_CONSUMED BIT(0) +#define NETSEC_XDP_TX BIT(1) +#define NETSEC_XDP_REDIR BIT(2) + enum ring_id { NETSEC_RING_TX = 0, NETSEC_RING_RX @@ -256,11 +263,13 @@ struct netsec_desc_ring { void *vaddr; u16 pkt_cnt; u16 head, tail; + struct xdp_rxq_info xdp_rxq; }; struct netsec_priv { struct netsec_desc_ring desc_ring[NETSEC_RING_MAX]; struct ethtool_coalesce et_coalesce; + struct bpf_prog *xdp_prog; spinlock_t reglock; /* protect reg access */ struct napi_struct napi; phy_interface_t phy_interface; @@ -297,6 +306,8 @@ struct netsec_rx_pkt_info { }; static void netsec_rx_fill(struct netsec_priv *priv, u16 from, u16 num); +static u32 netsec_run_xdp(struct netsec_desc *desc, struct netsec_priv *priv, + struct bpf_prog *prog, u16 len); static void *netsec_alloc_rx_data(struct netsec_priv *priv, dma_addr_t *dma_addr, u16 *len); @@ -613,13 +624,23 @@ static int netsec_clean_tx_dring(struct netsec_priv *priv, int budget) eop = (entry->attr >> NETSEC_TX_LAST) & 1; - dma_unmap_single(priv->dev, desc->dma_addr, desc->len, - DMA_TO_DEVICE); - if (eop) { - pkts++; + if (desc->skb) { + dma_unmap_single(priv->dev, desc->dma_addr, desc->len, + DMA_TO_DEVICE); + } + + if (!eop) { + *desc = (struct netsec_desc){}; + continue; + } + + if (!desc->skb) { + skb_free_frag(desc->addr); + } else { bytes += desc->skb->len; dev_kfree_skb(desc->skb); } + pkts++; *desc = (struct netsec_desc){}; } dring->pkt_cnt -= budget; @@ -659,8 +680,11 @@ static void nsetsec_adv_desc(u16 *idx) static int netsec_process_rx(struct netsec_priv *priv, int budget) { struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_RX]; + struct bpf_prog *xdp_prog = READ_ONCE(priv->xdp_prog); struct net_device *ndev = priv->ndev; - struct sk_buff *skb; + struct sk_buff *skb = NULL; + u32 xdp_flush = 0; + u32 xdp_result; int done = 0; while (done < budget) { @@ -707,6 +731,26 @@ static int netsec_process_rx(struct netsec_priv *priv, int budget) if (unlikely(!buf_addr)) break; + if (xdp_prog) { + xdp_result = netsec_run_xdp(desc, priv, xdp_prog, + pkt_len); + if (xdp_result != NETSEC_XDP_PASS) { + xdp_flush |= xdp_result & NETSEC_XDP_REDIR; + + dma_unmap_single_attrs(priv->dev, + desc->dma_addr, + desc->len, DMA_TO_DEVICE, + DMA_ATTR_SKIP_CPU_SYNC); + + desc->len = desc_len; + desc->dma_addr = dma_handle; + desc->addr = buf_addr; + netsec_rx_fill(priv, idx, 1); + nsetsec_adv_desc(&dring->tail); + } + continue; + } + skb = build_skb(desc->addr, desc->len); if (unlikely(!skb)) { dma_unmap_single(priv->dev, dma_handle, desc_len, @@ -740,6 +784,9 @@ static int netsec_process_rx(struct netsec_priv *priv, int budget) nsetsec_adv_desc(&dring->tail); } + if (xdp_flush & NETSEC_XDP_REDIR) + xdp_do_flush_map(); + return done; } @@ -892,6 +939,9 @@ static void netsec_uninit_pkt_dring(struct netsec_priv *priv, int id) if (!dring->vaddr || !dring->desc) return; + if (xdp_rxq_info_is_reg(&dring->xdp_rxq)) + xdp_rxq_info_unreg(&dring->xdp_rxq); + for (idx = 0; idx < DESC_NUM; idx++) { desc = &dring->desc[idx]; if (!desc->addr) @@ -994,7 +1044,7 @@ static int netsec_alloc_dring(struct netsec_priv *priv, enum ring_id id) static int netsec_setup_rx_dring(struct netsec_priv *priv) { struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_RX]; - int i; + int i, err; for (i = 0; i < DESC_NUM; i++) { struct netsec_desc *desc = &dring->desc[i]; @@ -1003,20 +1053,29 @@ static int netsec_setup_rx_dring(struct netsec_priv *priv) u16 len; buf = netsec_alloc_rx_data(priv, &dma_handle, &len); - if (!buf) { - netsec_uninit_pkt_dring(priv, NETSEC_RING_RX); + if (!buf) goto err_out; - } desc->dma_addr = dma_handle; desc->addr = buf; desc->len = len; } netsec_rx_fill(priv, 0, DESC_NUM); + err = xdp_rxq_info_reg(&dring->xdp_rxq, priv->ndev, 0); + if (err) + goto err_out; + + err = xdp_rxq_info_reg_mem_model(&dring->xdp_rxq, MEM_TYPE_PAGE_SHARED, + NULL); + if (err) { + xdp_rxq_info_unreg(&dring->xdp_rxq); + goto err_out; + } return 0; err_out: + netsec_uninit_pkt_dring(priv, NETSEC_RING_RX); return -ENOMEM; } @@ -1353,6 +1412,9 @@ static int netsec_netdev_stop(struct net_device *ndev) napi_disable(&priv->napi); + if (priv->xdp_prog) + bpf_prog_put(priv->xdp_prog); + netsec_write(priv, NETSEC_REG_INTEN_CLR, ~0); netsec_stop_gmac(priv); @@ -1420,6 +1482,136 @@ static int netsec_netdev_ioctl(struct net_device *ndev, struct ifreq *ifr, return phy_mii_ioctl(ndev->phydev, ifr, cmd); } +static u32 netsec_xmit_xdp(struct netsec_priv *priv, struct xdp_buff *xdp, + struct netsec_desc *rx_desc) +{ + struct netsec_desc_ring *tx_ring = &priv->desc_ring[NETSEC_RING_TX]; + struct netsec_tx_pkt_ctrl tx_ctrl = {}; + struct netsec_desc tx_desc; + int filled; + u32 len; + + len = xdp->data_end - xdp->data; + + if (tx_ring->head >= tx_ring->tail) + filled = tx_ring->head - tx_ring->tail; + else + filled = tx_ring->head + DESC_NUM - tx_ring->tail; + + if (DESC_NUM - filled <= 1) + return NETSEC_XDP_CONSUMED; + + dma_sync_single_for_device(priv->dev, rx_desc->dma_addr, len, + DMA_TO_DEVICE); + + tx_desc.dma_addr = rx_desc->dma_addr; + tx_desc.addr = xdp->data; + tx_desc.len = len; + + netsec_set_tx_de(priv, tx_ring, &tx_ctrl, &tx_desc, NULL); + netsec_write(priv, NETSEC_REG_NRM_TX_PKTCNT, 1); /* submit another tx */ + + return NETSEC_XDP_TX; +} + +static u32 netsec_run_xdp(struct netsec_desc *desc, struct netsec_priv *priv, + struct bpf_prog *prog, u16 len) + +{ + struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_RX]; + struct xdp_buff xdp; + u32 ret = NETSEC_XDP_PASS; + int err; + u32 act; + + xdp.data_hard_start = desc->addr; + xdp.data = desc->addr; + xdp_set_data_meta_invalid(&xdp); + xdp.data_end = xdp.data + len; + xdp.rxq = &dring->xdp_rxq; + + rcu_read_lock(); + act = bpf_prog_run_xdp(prog, &xdp); + + switch (act) { + case XDP_PASS: + ret = NETSEC_XDP_PASS; + break; + case XDP_TX: + ret = netsec_xmit_xdp(priv, &xdp, desc); + break; + case XDP_REDIRECT: + err = xdp_do_redirect(priv->ndev, &xdp, prog); + if (!err) { + ret = NETSEC_XDP_REDIR; + } else { + ret = NETSEC_XDP_CONSUMED; + xdp_return_buff(&xdp); + } + break; + default: + bpf_warn_invalid_xdp_action(act); + /* fall through */ + case XDP_ABORTED: + trace_xdp_exception(priv->ndev, prog, act); + /* fall through -- handle aborts by dropping packet */ + case XDP_DROP: + ret = NETSEC_XDP_CONSUMED; + break; + } + + rcu_read_unlock(); + + return ret; +} + +static int netsec_xdp_setup(struct netsec_priv *priv, struct bpf_prog *prog) +{ + struct net_device *dev = priv->ndev; + struct bpf_prog *old_prog; + + /* For now just support only the usual MTU sized frames */ + if (prog && dev->mtu > 1500) { + netdev_warn(dev, "Jumbo frames not yet supported with XDP\n"); + return -EOPNOTSUPP; + } + + if (netif_running(dev)) + netsec_netdev_stop(dev); + + /* Detach old prog, if any */ + old_prog = xchg(&priv->xdp_prog, prog); + if (old_prog) + bpf_prog_put(old_prog); + + if (priv->xdp_prog) { + /* Attach BPF program */ + priv->xdp_prog = bpf_prog_add(priv->xdp_prog, 1); + if (IS_ERR(priv->xdp_prog)) + return PTR_ERR(priv->xdp_prog); + } + + if (netif_running(dev)) + netsec_netdev_open(dev); + + return 0; +} + +static int netsec_xdp(struct net_device *ndev, struct netdev_bpf *xdp) +{ + struct netsec_priv *priv = netdev_priv(ndev); + + switch (xdp->command) { + case XDP_SETUP_PROG: + return netsec_xdp_setup(priv, xdp->prog); + case XDP_QUERY_PROG: + xdp->prog_id = priv->xdp_prog ? priv->xdp_prog->aux->id : 0; + return 0; + default: + return -EINVAL; + } +} + static const struct net_device_ops netsec_netdev_ops = { .ndo_init = netsec_netdev_init, .ndo_uninit = netsec_netdev_uninit, @@ -1430,6 +1622,7 @@ static const struct net_device_ops netsec_netdev_ops = { .ndo_set_mac_address = eth_mac_addr, .ndo_validate_addr = eth_validate_addr, .ndo_do_ioctl = netsec_netdev_ioctl, + .ndo_bpf = netsec_xdp, }; static int netsec_of_probe(struct platform_device *pdev, -- 2.7.4