From: Vladimir Oltean <vladimir.oltean@xxxxxxx> The driver implementation of the XDP_REDIRECT action reuses parts from XDP_TX, most notably the enetc_xdp_tx function which transmits an array of TX software BDs. Only this time, the buffers don't have DMA mappings, we need to create them. When a BPF program reaches the XDP_REDIRECT verdict for a frame, we can employ the same buffer reuse strategy as for the normal processing path and for XDP_PASS: we can flip to the other page half and seed that to the RX ring. Note that scatter/gather support is there, but disabled due to lack of multi-buffer support in XDP (which is added by this series): https://patchwork.kernel.org/project/netdevbpf/cover/cover.1616179034.git.lorenzo@xxxxxxxxxx/ Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx> --- drivers/net/ethernet/freescale/enetc/enetc.c | 212 +++++++++++++++++- drivers/net/ethernet/freescale/enetc/enetc.h | 11 +- .../ethernet/freescale/enetc/enetc_ethtool.c | 6 + .../net/ethernet/freescale/enetc/enetc_pf.c | 1 + 4 files changed, 218 insertions(+), 12 deletions(-) diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c index ba5313a5d7a4..57049ae97201 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.c +++ b/drivers/net/ethernet/freescale/enetc/enetc.c @@ -8,6 +8,23 @@ #include <linux/vmalloc.h> #include <net/pkt_sched.h> +static struct sk_buff *enetc_tx_swbd_get_skb(struct enetc_tx_swbd *tx_swbd) +{ + if (tx_swbd->is_xdp_tx || tx_swbd->is_xdp_redirect) + return NULL; + + return tx_swbd->skb; +} + +static struct xdp_frame * +enetc_tx_swbd_get_xdp_frame(struct enetc_tx_swbd *tx_swbd) +{ + if (tx_swbd->is_xdp_redirect) + return tx_swbd->xdp_frame; + + return NULL; +} + static void enetc_unmap_tx_buff(struct enetc_bdr *tx_ring, struct enetc_tx_swbd *tx_swbd) { @@ -25,14 +42,20 @@ static void enetc_unmap_tx_buff(struct enetc_bdr *tx_ring, tx_swbd->dma = 0; } -static void enetc_free_tx_skb(struct enetc_bdr *tx_ring, - struct enetc_tx_swbd *tx_swbd) +static void enetc_free_tx_frame(struct enetc_bdr *tx_ring, + struct enetc_tx_swbd *tx_swbd) { + struct xdp_frame *xdp_frame = enetc_tx_swbd_get_xdp_frame(tx_swbd); + struct sk_buff *skb = enetc_tx_swbd_get_skb(tx_swbd); + if (tx_swbd->dma) enetc_unmap_tx_buff(tx_ring, tx_swbd); - if (tx_swbd->skb) { - dev_kfree_skb_any(tx_swbd->skb); + if (xdp_frame) { + xdp_return_frame(tx_swbd->xdp_frame); + tx_swbd->xdp_frame = NULL; + } else if (skb) { + dev_kfree_skb_any(skb); tx_swbd->skb = NULL; } } @@ -183,7 +206,7 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb, do { tx_swbd = &tx_ring->tx_swbd[i]; - enetc_free_tx_skb(tx_ring, tx_swbd); + enetc_free_tx_frame(tx_ring, tx_swbd); if (i == 0) i = tx_ring->bd_count; i--; @@ -381,6 +404,9 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget) do_tstamp = false; while (bds_to_clean && tx_frm_cnt < ENETC_DEFAULT_TX_WORK) { + struct xdp_frame *xdp_frame = enetc_tx_swbd_get_xdp_frame(tx_swbd); + struct sk_buff *skb = enetc_tx_swbd_get_skb(tx_swbd); + if (unlikely(tx_swbd->check_wb)) { struct enetc_ndev_priv *priv = netdev_priv(ndev); union enetc_tx_bd *txbd; @@ -400,12 +426,15 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget) else if (likely(tx_swbd->dma)) enetc_unmap_tx_buff(tx_ring, tx_swbd); - if (tx_swbd->skb) { + if (xdp_frame) { + xdp_return_frame(xdp_frame); + tx_swbd->xdp_frame = NULL; + } else if (skb) { if (unlikely(do_tstamp)) { - enetc_tstamp_tx(tx_swbd->skb, tstamp); + enetc_tstamp_tx(skb, tstamp); do_tstamp = false; } - napi_consume_skb(tx_swbd->skb, napi_budget); + napi_consume_skb(skb, napi_budget); tx_swbd->skb = NULL; } @@ -827,6 +856,109 @@ static bool enetc_xdp_tx(struct enetc_bdr *tx_ring, return true; } +static int enetc_xdp_frame_to_xdp_tx_swbd(struct enetc_bdr *tx_ring, + struct enetc_tx_swbd *xdp_tx_arr, + struct xdp_frame *xdp_frame) +{ + struct enetc_tx_swbd *xdp_tx_swbd = &xdp_tx_arr[0]; + struct skb_shared_info *shinfo; + void *data = xdp_frame->data; + int len = xdp_frame->len; + skb_frag_t *frag; + dma_addr_t dma; + unsigned int f; + int n = 0; + + dma = dma_map_single(tx_ring->dev, data, len, DMA_TO_DEVICE); + if (unlikely(dma_mapping_error(tx_ring->dev, dma))) { + netdev_err(tx_ring->ndev, "DMA map error\n"); + return -1; + } + + xdp_tx_swbd->dma = dma; + xdp_tx_swbd->dir = DMA_TO_DEVICE; + xdp_tx_swbd->len = len; + xdp_tx_swbd->is_xdp_redirect = true; + xdp_tx_swbd->is_eof = false; + xdp_tx_swbd->xdp_frame = NULL; + + n++; + xdp_tx_swbd = &xdp_tx_arr[n]; + + shinfo = xdp_get_shared_info_from_frame(xdp_frame); + + for (f = 0, frag = &shinfo->frags[0]; f < shinfo->nr_frags; + f++, frag++) { + data = skb_frag_address(frag); + len = skb_frag_size(frag); + + dma = dma_map_single(tx_ring->dev, data, len, DMA_TO_DEVICE); + if (unlikely(dma_mapping_error(tx_ring->dev, dma))) { + /* Undo the DMA mapping for all fragments */ + while (n-- >= 0) + enetc_unmap_tx_buff(tx_ring, &xdp_tx_arr[n]); + + netdev_err(tx_ring->ndev, "DMA map error\n"); + return -1; + } + + xdp_tx_swbd->dma = dma; + xdp_tx_swbd->dir = DMA_TO_DEVICE; + xdp_tx_swbd->len = len; + xdp_tx_swbd->is_xdp_redirect = true; + xdp_tx_swbd->is_eof = false; + xdp_tx_swbd->xdp_frame = NULL; + + n++; + xdp_tx_swbd = &xdp_tx_arr[n]; + } + + xdp_tx_arr[n - 1].is_eof = true; + xdp_tx_arr[n - 1].xdp_frame = xdp_frame; + + return n; +} + +int enetc_xdp_xmit(struct net_device *ndev, int num_frames, + struct xdp_frame **frames, u32 flags) +{ + struct enetc_tx_swbd xdp_redirect_arr[ENETC_MAX_SKB_FRAGS] = {0}; + struct enetc_ndev_priv *priv = netdev_priv(ndev); + struct enetc_bdr *tx_ring; + int xdp_tx_bd_cnt, i, k; + int xdp_tx_frm_cnt = 0; + + tx_ring = priv->tx_ring[smp_processor_id()]; + + prefetchw(ENETC_TXBD(*tx_ring, tx_ring->next_to_use)); + + for (k = 0; k < num_frames; k++) { + xdp_tx_bd_cnt = enetc_xdp_frame_to_xdp_tx_swbd(tx_ring, + xdp_redirect_arr, + frames[k]); + if (unlikely(xdp_tx_bd_cnt < 0)) + break; + + if (unlikely(!enetc_xdp_tx(tx_ring, xdp_redirect_arr, + xdp_tx_bd_cnt))) { + for (i = 0; i < xdp_tx_bd_cnt; i++) + enetc_unmap_tx_buff(tx_ring, + &xdp_redirect_arr[i]); + tx_ring->stats.xdp_tx_drops++; + break; + } + + xdp_tx_frm_cnt++; + } + + if (unlikely((flags & XDP_XMIT_FLUSH) || k != xdp_tx_frm_cnt)) + enetc_update_tx_ring_tail(tx_ring); + + tx_ring->stats.xdp_tx += xdp_tx_frm_cnt; + + return xdp_tx_frm_cnt; +} + static void enetc_map_rx_buff_to_xdp(struct enetc_bdr *rx_ring, int i, struct xdp_buff *xdp_buff, u16 size) { @@ -948,14 +1080,31 @@ static void enetc_xdp_drop(struct enetc_bdr *rx_ring, int rx_ring_first, rx_ring->stats.xdp_drops++; } +static void enetc_xdp_free(struct enetc_bdr *rx_ring, int rx_ring_first, + int rx_ring_last) +{ + while (rx_ring_first != rx_ring_last) { + struct enetc_rx_swbd *rx_swbd = &rx_ring->rx_swbd[rx_ring_first]; + + if (rx_swbd->page) { + dma_unmap_page(rx_ring->dev, rx_swbd->dma, PAGE_SIZE, + rx_swbd->dir); + __free_page(rx_swbd->page); + rx_swbd->page = NULL; + } + enetc_bdr_idx_inc(rx_ring, &rx_ring_first); + } + rx_ring->stats.xdp_redirect_failures++; +} + static int enetc_clean_rx_ring_xdp(struct enetc_bdr *rx_ring, struct napi_struct *napi, int work_limit, struct bpf_prog *prog) { + int xdp_tx_bd_cnt, xdp_tx_frm_cnt = 0, xdp_redirect_frm_cnt = 0; struct enetc_tx_swbd xdp_tx_arr[ENETC_MAX_SKB_FRAGS] = {0}; struct enetc_ndev_priv *priv = netdev_priv(rx_ring->ndev); struct enetc_bdr *tx_ring = priv->tx_ring[rx_ring->index]; - int xdp_tx_bd_cnt, xdp_tx_frm_cnt = 0; int rx_frm_cnt = 0, rx_byte_cnt = 0; int cleaned_cnt, i; u32 xdp_act; @@ -969,6 +1118,7 @@ static int enetc_clean_rx_ring_xdp(struct enetc_bdr *rx_ring, int orig_i, orig_cleaned_cnt; struct xdp_buff xdp_buff; struct sk_buff *skb; + int tmp_orig_i, err; u32 bd_status; rxbd = enetc_rxbd(rx_ring, i); @@ -1026,6 +1176,43 @@ static int enetc_clean_rx_ring_xdp(struct enetc_bdr *rx_ring, rx_ring->xdp.xdp_tx_in_flight += xdp_tx_bd_cnt; xdp_tx_frm_cnt++; } + break; + case XDP_REDIRECT: + /* xdp_return_frame does not support S/G in the sense + * that it leaks the fragments (__xdp_return should not + * call page_frag_free only for the initial buffer). + * Until XDP_REDIRECT gains support for S/G let's keep + * the code structure in place, but dead. We drop the + * S/G frames ourselves to avoid memory leaks which + * would otherwise leave the kernel OOM. + */ + if (unlikely(cleaned_cnt - orig_cleaned_cnt != 1)) { + enetc_xdp_drop(rx_ring, orig_i, i); + rx_ring->stats.xdp_redirect_sg++; + break; + } + + tmp_orig_i = orig_i; + + while (orig_i != i) { + enetc_put_rx_buff(rx_ring, + &rx_ring->rx_swbd[orig_i]); + enetc_bdr_idx_inc(rx_ring, &orig_i); + } + + err = xdp_do_redirect(rx_ring->ndev, &xdp_buff, prog); + if (unlikely(err)) { + enetc_xdp_free(rx_ring, tmp_orig_i, i); + } else { + xdp_redirect_frm_cnt++; + rx_ring->stats.xdp_redirect++; + } + + if (unlikely(xdp_redirect_frm_cnt > ENETC_DEFAULT_TX_WORK)) { + xdp_do_flush_map(); + xdp_redirect_frm_cnt = 0; + } + break; default: bpf_warn_invalid_xdp_action(xdp_act); @@ -1039,6 +1226,9 @@ static int enetc_clean_rx_ring_xdp(struct enetc_bdr *rx_ring, rx_ring->stats.packets += rx_frm_cnt; rx_ring->stats.bytes += rx_byte_cnt; + if (xdp_redirect_frm_cnt) + xdp_do_flush_map(); + if (xdp_tx_frm_cnt) enetc_update_tx_ring_tail(tx_ring); @@ -1173,7 +1363,7 @@ static void enetc_free_txbdr(struct enetc_bdr *txr) int size, i; for (i = 0; i < txr->bd_count; i++) - enetc_free_tx_skb(txr, &txr->tx_swbd[i]); + enetc_free_tx_frame(txr, &txr->tx_swbd[i]); size = txr->bd_count * sizeof(union enetc_tx_bd); @@ -1290,7 +1480,7 @@ static void enetc_free_tx_ring(struct enetc_bdr *tx_ring) for (i = 0; i < tx_ring->bd_count; i++) { struct enetc_tx_swbd *tx_swbd = &tx_ring->tx_swbd[i]; - enetc_free_tx_skb(tx_ring, tx_swbd); + enetc_free_tx_frame(tx_ring, tx_swbd); } tx_ring->next_to_clean = 0; diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h index d0619fcbbe97..05474f46b0d9 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.h +++ b/drivers/net/ethernet/freescale/enetc/enetc.h @@ -19,7 +19,10 @@ (ETH_FCS_LEN + ETH_HLEN + VLAN_HLEN)) struct enetc_tx_swbd { - struct sk_buff *skb; + union { + struct sk_buff *skb; + struct xdp_frame *xdp_frame; + }; dma_addr_t dma; struct page *page; /* valid only if is_xdp_tx */ u16 page_offset; /* valid only if is_xdp_tx */ @@ -30,6 +33,7 @@ struct enetc_tx_swbd { u8 do_tstamp:1; u8 is_eof:1; u8 is_xdp_tx:1; + u8 is_xdp_redirect:1; }; #define ENETC_RX_MAXFRM_SIZE ENETC_MAC_MAXFRM_SIZE @@ -61,6 +65,9 @@ struct enetc_ring_stats { unsigned int xdp_drops; unsigned int xdp_tx; unsigned int xdp_tx_drops; + unsigned int xdp_redirect; + unsigned int xdp_redirect_failures; + unsigned int xdp_redirect_sg; unsigned int recycles; unsigned int recycle_failures; }; @@ -354,6 +361,8 @@ int enetc_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd); int enetc_setup_tc(struct net_device *ndev, enum tc_setup_type type, void *type_data); int enetc_setup_bpf(struct net_device *dev, struct netdev_bpf *xdp); +int enetc_xdp_xmit(struct net_device *ndev, int num_frames, + struct xdp_frame **frames, u32 flags); /* ethtool */ void enetc_set_ethtool_ops(struct net_device *ndev); diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c index 37821a8b225e..7cc81b453bd7 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c +++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c @@ -195,6 +195,9 @@ static const char rx_ring_stats[][ETH_GSTRING_LEN] = { "Rx ring %2d XDP drops", "Rx ring %2d recycles", "Rx ring %2d recycle failures", + "Rx ring %2d redirects", + "Rx ring %2d redirect failures", + "Rx ring %2d redirect S/G", }; static const char tx_ring_stats[][ETH_GSTRING_LEN] = { @@ -284,6 +287,9 @@ static void enetc_get_ethtool_stats(struct net_device *ndev, data[o++] = priv->rx_ring[i]->stats.xdp_drops; data[o++] = priv->rx_ring[i]->stats.recycles; data[o++] = priv->rx_ring[i]->stats.recycle_failures; + data[o++] = priv->rx_ring[i]->stats.xdp_redirect; + data[o++] = priv->rx_ring[i]->stats.xdp_redirect_failures; + data[o++] = priv->rx_ring[i]->stats.xdp_redirect_sg; } if (!enetc_si_is_pf(priv->si)) diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.c b/drivers/net/ethernet/freescale/enetc/enetc_pf.c index 0484dbe13422..f61fedf462e5 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c +++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c @@ -708,6 +708,7 @@ static const struct net_device_ops enetc_ndev_ops = { .ndo_do_ioctl = enetc_ioctl, .ndo_setup_tc = enetc_setup_tc, .ndo_bpf = enetc_setup_bpf, + .ndo_xdp_xmit = enetc_xdp_xmit, }; static void enetc_pf_netdev_setup(struct enetc_si *si, struct net_device *ndev, -- 2.25.1
