[PATCH net-next v3 6/6] net: stmmac: Add support for XDP_REDIRECT action
From: Ong Boon Leong <hidden>
Date: 2021-03-31 15:39:01
Also in:
bpf, linux-arm-kernel, lkml
Subsystem:
networking drivers, stmmac ethernet driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
This patch adds the support of XDP_REDIRECT to another remote cpu for
further action. It also implements ndo_xdp_xmit ops, enabling the driver
to transmit packets forwarded to it by XDP program running on another
interface.
This patch has been tested using "xdp_redirect_cpu" for XDP_REDIRECT
+ drop testing. It also been tested with "xdp_redirect" sample app
which can be used to exercise ndo_xdp_xmit ops. The burst traffics are
generated using pktgen_sample03_burst_single_flow.sh in samples/pktgen
directory.
v3: Added 'nq->trans_start = jiffies' to avoid TX time-out as we are
sharing TX queue between slow path and XDP. Thanks to Jakub Kicinski
for point out.
Signed-off-by: Ong Boon Leong <redacted>
---
drivers/net/ethernet/stmicro/stmmac/stmmac.h | 1 +
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 98 +++++++++++++++++--
2 files changed, 89 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index a93e22a6be59..c49debb62b05 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h@@ -39,6 +39,7 @@ struct stmmac_resources { enum stmmac_txbuf_type { STMMAC_TXBUF_T_SKB, STMMAC_TXBUF_T_XDP_TX, + STMMAC_TXBUF_T_XDP_NDO, }; struct stmmac_tx_info {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 35e9a738d663..370b3c084dda 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c@@ -72,6 +72,7 @@ MODULE_PARM_DESC(phyaddr, "Physical device address"); #define STMMAC_XDP_PASS 0 #define STMMAC_XDP_CONSUMED BIT(0) #define STMMAC_XDP_TX BIT(1) +#define STMMAC_XDP_REDIRECT BIT(2) static int flow_ctrl = FLOW_AUTO; module_param(flow_ctrl, int, 0644);
@@ -1458,7 +1459,8 @@ static void stmmac_free_tx_buffer(struct stmmac_priv *priv, u32 queue, int i) } if (tx_q->xdpf[i] && - tx_q->tx_skbuff_dma[i].buf_type == STMMAC_TXBUF_T_XDP_TX) { + (tx_q->tx_skbuff_dma[i].buf_type == STMMAC_TXBUF_T_XDP_TX || + tx_q->tx_skbuff_dma[i].buf_type == STMMAC_TXBUF_T_XDP_NDO)) { xdp_return_frame(tx_q->xdpf[i]); tx_q->xdpf[i] = NULL; }
@@ -2220,7 +2222,8 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue) struct dma_desc *p; int status; - if (tx_q->tx_skbuff_dma[entry].buf_type == STMMAC_TXBUF_T_XDP_TX) { + if (tx_q->tx_skbuff_dma[entry].buf_type == STMMAC_TXBUF_T_XDP_TX || + tx_q->tx_skbuff_dma[entry].buf_type == STMMAC_TXBUF_T_XDP_NDO) { xdpf = tx_q->xdpf[entry]; skb = NULL; } else if (tx_q->tx_skbuff_dma[entry].buf_type == STMMAC_TXBUF_T_SKB) {
@@ -2292,6 +2295,12 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue) tx_q->xdpf[entry] = NULL; } + if (xdpf && + tx_q->tx_skbuff_dma[entry].buf_type == STMMAC_TXBUF_T_XDP_NDO) { + xdp_return_frame(xdpf); + tx_q->xdpf[entry] = NULL; + } + if (tx_q->tx_skbuff_dma[entry].buf_type == STMMAC_TXBUF_T_SKB) { if (likely(skb)) { pkts_compl++;
@@ -4246,10 +4255,9 @@ static unsigned int stmmac_rx_buf2_len(struct stmmac_priv *priv, } static int stmmac_xdp_xmit_xdpf(struct stmmac_priv *priv, int queue, - struct xdp_frame *xdpf) + struct xdp_frame *xdpf, bool dma_map) { struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue]; - struct page *page = virt_to_page(xdpf->data); unsigned int entry = tx_q->cur_tx; struct dma_desc *tx_desc; dma_addr_t dma_addr;
@@ -4265,12 +4273,23 @@ static int stmmac_xdp_xmit_xdpf(struct stmmac_priv *priv, int queue, else tx_desc = tx_q->dma_tx + entry; - dma_addr = page_pool_get_dma_addr(page) + sizeof(*xdpf) + - xdpf->headroom; - dma_sync_single_for_device(priv->device, dma_addr, - xdpf->len, DMA_BIDIRECTIONAL); + if (dma_map) { + dma_addr = dma_map_single(priv->device, xdpf->data, + xdpf->len, DMA_TO_DEVICE); + if (dma_mapping_error(priv->device, dma_addr)) + return STMMAC_XDP_CONSUMED; + + tx_q->tx_skbuff_dma[entry].buf_type = STMMAC_TXBUF_T_XDP_NDO; + } else { + struct page *page = virt_to_page(xdpf->data); - tx_q->tx_skbuff_dma[entry].buf_type = STMMAC_TXBUF_T_XDP_TX; + dma_addr = page_pool_get_dma_addr(page) + sizeof(*xdpf) + + xdpf->headroom; + dma_sync_single_for_device(priv->device, dma_addr, + xdpf->len, DMA_BIDIRECTIONAL); + + tx_q->tx_skbuff_dma[entry].buf_type = STMMAC_TXBUF_T_XDP_TX; + } tx_q->tx_skbuff_dma[entry].buf = dma_addr; tx_q->tx_skbuff_dma[entry].map_as_page = false;
@@ -4339,7 +4358,7 @@ static int stmmac_xdp_xmit_back(struct stmmac_priv *priv, __netif_tx_lock(nq, cpu); /* Avoids TX time-out as we are sharing with slow path */ nq->trans_start = jiffies; - res = stmmac_xdp_xmit_xdpf(priv, queue, xdpf); + res = stmmac_xdp_xmit_xdpf(priv, queue, xdpf, false); if (res == STMMAC_XDP_TX) { stmmac_flush_tx_descriptors(priv, queue); stmmac_tx_timer_arm(priv, queue);
@@ -4372,6 +4391,12 @@ static struct sk_buff *stmmac_xdp_run_prog(struct stmmac_priv *priv, case XDP_TX: res = stmmac_xdp_xmit_back(priv, xdp); break; + case XDP_REDIRECT: + if (xdp_do_redirect(priv->dev, xdp, prog) < 0) + res = STMMAC_XDP_CONSUMED; + else + res = STMMAC_XDP_REDIRECT; + break; default: bpf_warn_invalid_xdp_action(act); fallthrough;
@@ -4407,6 +4432,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) unsigned int desc_size; struct sk_buff *skb = NULL; struct xdp_buff xdp; + int xdp_status = 0; int buf_sz; dma_dir = page_pool_get_dma_dir(rx_q->page_pool);
@@ -4576,6 +4602,12 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) skb = NULL; count++; continue; + } else if (xdp_res & STMMAC_XDP_REDIRECT) { + xdp_status |= xdp_res; + buf->page = NULL; + skb = NULL; + count++; + continue; } } }
@@ -4658,6 +4690,9 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) rx_q->state.len = len; } + if (xdp_status & STMMAC_XDP_REDIRECT) + xdp_do_flush(); + stmmac_rx_refill(priv, queue); priv->xstats.rx_pkt_n += count;
@@ -5584,6 +5619,48 @@ static int stmmac_bpf(struct net_device *dev, struct netdev_bpf *bpf) } } +static int stmmac_xdp_xmit(struct net_device *dev, int num_frames, + struct xdp_frame **frames, u32 flags) +{ + struct stmmac_priv *priv = netdev_priv(dev); + int cpu = smp_processor_id(); + struct netdev_queue *nq; + int i, nxmit = 0; + int queue; + + if (unlikely(test_bit(STMMAC_DOWN, &priv->state))) + return -ENETDOWN; + + if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) + return -EINVAL; + + queue = stmmac_xdp_get_tx_queue(priv, cpu); + nq = netdev_get_tx_queue(priv->dev, queue); + + __netif_tx_lock(nq, cpu); + /* Avoids TX time-out as we are sharing with slow path */ + nq->trans_start = jiffies; + + for (i = 0; i < num_frames; i++) { + int res; + + res = stmmac_xdp_xmit_xdpf(priv, queue, frames[i], true); + if (res == STMMAC_XDP_CONSUMED) + break; + + nxmit++; + } + + if (flags & XDP_XMIT_FLUSH) { + stmmac_flush_tx_descriptors(priv, queue); + stmmac_tx_timer_arm(priv, queue); + } + + __netif_tx_unlock(nq); + + return nxmit; +} + static const struct net_device_ops stmmac_netdev_ops = { .ndo_open = stmmac_open, .ndo_start_xmit = stmmac_xmit,
@@ -5603,6 +5680,7 @@ static const struct net_device_ops stmmac_netdev_ops = { .ndo_vlan_rx_add_vid = stmmac_vlan_rx_add_vid, .ndo_vlan_rx_kill_vid = stmmac_vlan_rx_kill_vid, .ndo_bpf = stmmac_bpf, + .ndo_xdp_xmit = stmmac_xdp_xmit, }; static void stmmac_reset_subtask(struct stmmac_priv *priv)
--
2.25.1