Add XDP_TX verdict support, also introduce ndo_xdp_xmit function for redirection, and update macb_tx_unmap() to handle both skbs and xdp frames advertising NETDEV_XDP_ACT_NDO_XMIT capability and the ability to process XDP_TX verdicts. Signed-off-by: Paolo Valerio --- drivers/net/ethernet/cadence/macb_main.c | 171 +++++++++++++++++++++-- 1 file changed, 162 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index 50646ee90672..69392ec0065f 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -967,6 +967,17 @@ static int macb_halt_tx(struct macb *bp) bp, TSR); } +static void macb_tx_release_buff(void *buff, enum macb_tx_buff_type type, int budget) +{ + if (type == MACB_TYPE_SKB) { + napi_consume_skb(buff, budget); + } else if (type == MACB_TYPE_XDP_TX) { + xdp_return_frame_rx_napi(buff); + } else { + xdp_return_frame(buff); + } +} + static void macb_tx_unmap(struct macb *bp, struct macb_tx_buff *tx_buff, int budget) { @@ -981,7 +992,7 @@ static void macb_tx_unmap(struct macb *bp, struct macb_tx_buff *tx_buff, } if (tx_buff->ptr) { - napi_consume_skb(tx_buff->ptr, budget); + macb_tx_release_buff(tx_buff->ptr, tx_buff->type, budget); tx_buff->ptr = NULL; } } @@ -1069,6 +1080,10 @@ static void macb_tx_error_task(struct work_struct *work) desc = macb_tx_desc(queue, tail); ctrl = desc->ctrl; tx_buff = macb_tx_buff(queue, tail); + + if (tx_buff->type != MACB_TYPE_SKB) + goto unmap; + skb = tx_buff->ptr; if (ctrl & MACB_BIT(TX_USED)) { @@ -1106,6 +1121,7 @@ static void macb_tx_error_task(struct work_struct *work) desc->ctrl = ctrl | MACB_BIT(TX_USED); } +unmap: macb_tx_unmap(bp, tx_buff, 0); } @@ -1184,6 +1200,7 @@ static int macb_tx_complete(struct macb_queue *queue, int budget) spin_lock_irqsave(&queue->tx_ptr_lock, flags); head = queue->tx_head; for (tail = queue->tx_tail; tail != head && packets < budget; tail++) { + void *data = NULL; struct macb_tx_buff *tx_buff; struct sk_buff *skb; struct macb_dma_desc *desc; @@ -1206,11 +1223,16 @@ static int macb_tx_complete(struct macb_queue *queue, int budget) for (;; tail++) { tx_buff = macb_tx_buff(queue, tail); - if (tx_buff->type == MACB_TYPE_SKB) - skb = tx_buff->ptr; + if (tx_buff->type != MACB_TYPE_SKB) { + data = tx_buff->ptr; + goto unmap; + } /* First, update TX stats if needed */ - if (skb) { + if (tx_buff->type == MACB_TYPE_SKB && tx_buff->ptr) { + data = tx_buff->ptr; + skb = tx_buff->ptr; + if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) && !ptp_one_step_sync(skb)) gem_ptp_do_txstamp(bp, skb, desc); @@ -1226,6 +1248,7 @@ static int macb_tx_complete(struct macb_queue *queue, int budget) bytes += skb->len; } +unmap: /* Now we can safely release resources */ macb_tx_unmap(bp, tx_buff, budget); @@ -1233,7 +1256,7 @@ static int macb_tx_complete(struct macb_queue *queue, int budget) * WARNING: at this point skb has been freed by * macb_tx_unmap(). */ - if (skb) + if (data) break; } } @@ -1363,10 +1386,127 @@ static void discard_partial_frame(struct macb_queue *queue, unsigned int begin, */ } +static int macb_xdp_submit_frame(struct macb *bp, struct xdp_frame *xdpf, + struct net_device *dev, bool dma_map, + dma_addr_t addr) +{ + enum macb_tx_buff_type buff_type; + struct macb_tx_buff *tx_buff; + int cpu = smp_processor_id(); + struct macb_dma_desc *desc; + struct macb_queue *queue; + unsigned int next_head; + unsigned long flags; + dma_addr_t mapping; + u16 queue_index; + int err = 0; + u32 ctrl; + + queue_index = cpu % bp->num_queues; + queue = &bp->queues[queue_index]; + buff_type = dma_map ? MACB_TYPE_XDP_NDO : MACB_TYPE_XDP_TX; + + spin_lock_irqsave(&queue->tx_ptr_lock, flags); + + /* This is a hard error, log it. */ + if (CIRC_SPACE(queue->tx_head, queue->tx_tail, bp->tx_ring_size) < 1) { + netif_stop_subqueue(dev, queue_index); + netdev_dbg(bp->dev, "tx_head = %u, tx_tail = %u\n", + queue->tx_head, queue->tx_tail); + err = -ENOMEM; + goto unlock; + } + + if (dma_map) { + mapping = dma_map_single(&bp->pdev->dev, + xdpf->data, + xdpf->len, DMA_TO_DEVICE); + if (unlikely(dma_mapping_error(&bp->pdev->dev, mapping))) { + err = -ENOMEM; + goto unlock; + } + } else { + mapping = addr; + dma_sync_single_for_device(&bp->pdev->dev, mapping, + xdpf->len, DMA_BIDIRECTIONAL); + } + + next_head = queue->tx_head + 1; + + ctrl = MACB_BIT(TX_USED); + desc = macb_tx_desc(queue, next_head); + desc->ctrl = ctrl; + + desc = macb_tx_desc(queue, queue->tx_head); + tx_buff = macb_tx_buff(queue, queue->tx_head); + tx_buff->ptr = xdpf; + tx_buff->type = buff_type; + tx_buff->mapping = dma_map ? mapping : 0; + tx_buff->size = xdpf->len; + tx_buff->mapped_as_page = false; + + ctrl = (u32)tx_buff->size; + ctrl |= MACB_BIT(TX_LAST); + + if (unlikely(macb_tx_ring_wrap(bp, queue->tx_head) == (bp->tx_ring_size - 1))) + ctrl |= MACB_BIT(TX_WRAP); + + /* Set TX buffer descriptor */ + macb_set_addr(bp, desc, mapping); + /* desc->addr must be visible to hardware before clearing + * 'TX_USED' bit in desc->ctrl. + */ + wmb(); + desc->ctrl = ctrl; + queue->tx_head = next_head; + + /* Make newly initialized descriptor visible to hardware */ + wmb(); + + spin_lock(&bp->lock); + macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(TSTART)); + spin_unlock(&bp->lock); + + if (CIRC_SPACE(queue->tx_head, queue->tx_tail, bp->tx_ring_size) < 1) + netif_stop_subqueue(dev, queue_index); + +unlock: + spin_unlock_irqrestore(&queue->tx_ptr_lock, flags); + + if (err) + macb_tx_release_buff(xdpf, buff_type, 0); + + return err; +} + +static int gem_xdp_xmit(struct net_device *dev, int num_frame, + struct xdp_frame **frames, u32 flags) +{ + struct macb *bp = netdev_priv(dev); + u32 xmitted = 0; + int i; + + if (!macb_is_gem(bp)) + return -EOPNOTSUPP; + + if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) + return -EINVAL; + + for (i = 0; i < num_frame; i++) { + if (macb_xdp_submit_frame(bp, frames[i], dev, true, 0)) + break; + + xmitted++; + } + + return xmitted; +} + static u32 gem_xdp_run(struct macb_queue *queue, void *buff_head, - unsigned int len) + unsigned int len, dma_addr_t addr) { struct net_device *dev; + struct xdp_frame *xdpf; struct bpf_prog *prog; struct xdp_buff xdp; @@ -1393,6 +1533,18 @@ static u32 gem_xdp_run(struct macb_queue *queue, void *buff_head, break; } goto out; + case XDP_TX: + xdpf = xdp_convert_buff_to_frame(&xdp); + + if (unlikely(!xdpf)) { + act = XDP_DROP; + break; + } + + if (macb_xdp_submit_frame(queue->bp, xdpf, dev, false, + addr)) + act = XDP_DROP; + goto out; default: bpf_warn_invalid_xdp_action(dev, prog, act); fallthrough; @@ -1480,7 +1632,7 @@ static int gem_rx(struct macb_queue *queue, struct napi_struct *napi, if (first_frame) { if (last_frame) { - ret = gem_xdp_run(queue, buff_head, data_len); + ret = gem_xdp_run(queue, buff_head, data_len, addr); if (ret == XDP_REDIRECT) xdp_flush = true; @@ -4620,6 +4772,7 @@ static const struct net_device_ops macb_netdev_ops = { .ndo_hwtstamp_get = macb_hwtstamp_get, .ndo_setup_tc = macb_setup_tc, .ndo_bpf = gem_xdp, + .ndo_xdp_xmit = gem_xdp_xmit, }; /* Configure peripheral capabilities according to device tree @@ -5920,8 +6073,8 @@ static int macb_probe(struct platform_device *pdev) if (macb_is_gem(bp)) dev->xdp_features = NETDEV_XDP_ACT_BASIC | - NETDEV_XDP_ACT_REDIRECT; - + NETDEV_XDP_ACT_REDIRECT | + NETDEV_XDP_ACT_NDO_XMIT; netif_carrier_off(dev); err = register_netdev(dev); -- 2.52.0