diff options
Diffstat (limited to 'target/linux/lantiq/patches-5.10/0704-v5.17-net-lantiq_xrx200-add-ingress-SG-DMA-support.patch')
| -rw-r--r-- | target/linux/lantiq/patches-5.10/0704-v5.17-net-lantiq_xrx200-add-ingress-SG-DMA-support.patch | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/target/linux/lantiq/patches-5.10/0704-v5.17-net-lantiq_xrx200-add-ingress-SG-DMA-support.patch b/target/linux/lantiq/patches-5.10/0704-v5.17-net-lantiq_xrx200-add-ingress-SG-DMA-support.patch new file mode 100644 index 0000000000..f2c36952fc --- /dev/null +++ b/target/linux/lantiq/patches-5.10/0704-v5.17-net-lantiq_xrx200-add-ingress-SG-DMA-support.patch @@ -0,0 +1,104 @@ +From c3e6b2c35b34214c58c1e90d65dab5f5393608e7 Mon Sep 17 00:00:00 2001 +From: Aleksander Jan Bajkowski <olek2@wp.pl> +Date: Mon, 3 Jan 2022 20:43:16 +0100 +Subject: [PATCH] net: lantiq_xrx200: add ingress SG DMA support + +This patch adds support for scatter gather DMA. DMA in PMAC splits +the packet into several buffers when the MTU on the CPU port is +less than the MTU of the switch. The first buffer starts at an +offset of NET_IP_ALIGN. In subsequent buffers, dma ignores the +offset. Thanks to this patch, the user can still connect to the +device in such a situation. For normal configurations, the patch +has no effect on performance. + +Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl> +Signed-off-by: David S. Miller <davem@davemloft.net> +--- + drivers/net/ethernet/lantiq_xrx200.c | 47 +++++++++++++++++++++++----- + 1 file changed, 40 insertions(+), 7 deletions(-) + +--- a/drivers/net/ethernet/lantiq_xrx200.c ++++ b/drivers/net/ethernet/lantiq_xrx200.c +@@ -26,6 +26,9 @@ + #define XRX200_DMA_RX 0 + #define XRX200_DMA_TX 1 + ++#define XRX200_DMA_PACKET_COMPLETE 0 ++#define XRX200_DMA_PACKET_IN_PROGRESS 1 ++ + /* cpu port mac */ + #define PMAC_RX_IPG 0x0024 + #define PMAC_RX_IPG_MASK 0xf +@@ -61,6 +64,9 @@ struct xrx200_chan { + struct ltq_dma_channel dma; + struct sk_buff *skb[LTQ_DESC_NUM]; + ++ struct sk_buff *skb_head; ++ struct sk_buff *skb_tail; ++ + struct xrx200_priv *priv; + }; + +@@ -204,7 +210,8 @@ static int xrx200_hw_receive(struct xrx2 + struct xrx200_priv *priv = ch->priv; + struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc]; + struct sk_buff *skb = ch->skb[ch->dma.desc]; +- int len = (desc->ctl & LTQ_DMA_SIZE_MASK); ++ u32 ctl = desc->ctl; ++ int len = (ctl & LTQ_DMA_SIZE_MASK); + struct net_device *net_dev = priv->net_dev; + int ret; + +@@ -220,12 +227,36 @@ static int xrx200_hw_receive(struct xrx2 + } + + skb_put(skb, len); +- skb->protocol = eth_type_trans(skb, net_dev); +- netif_receive_skb(skb); +- net_dev->stats.rx_packets++; +- net_dev->stats.rx_bytes += len; + +- return 0; ++ /* add buffers to skb via skb->frag_list */ ++ if (ctl & LTQ_DMA_SOP) { ++ ch->skb_head = skb; ++ ch->skb_tail = skb; ++ } else if (ch->skb_head) { ++ if (ch->skb_head == ch->skb_tail) ++ skb_shinfo(ch->skb_tail)->frag_list = skb; ++ else ++ ch->skb_tail->next = skb; ++ ch->skb_tail = skb; ++ skb_reserve(ch->skb_tail, -NET_IP_ALIGN); ++ ch->skb_head->len += skb->len; ++ ch->skb_head->data_len += skb->len; ++ ch->skb_head->truesize += skb->truesize; ++ } ++ ++ if (ctl & LTQ_DMA_EOP) { ++ ch->skb_head->protocol = eth_type_trans(ch->skb_head, net_dev); ++ netif_receive_skb(ch->skb_head); ++ net_dev->stats.rx_packets++; ++ net_dev->stats.rx_bytes += ch->skb_head->len; ++ ch->skb_head = NULL; ++ ch->skb_tail = NULL; ++ ret = XRX200_DMA_PACKET_COMPLETE; ++ } else { ++ ret = XRX200_DMA_PACKET_IN_PROGRESS; ++ } ++ ++ return ret; + } + + static int xrx200_poll_rx(struct napi_struct *napi, int budget) +@@ -240,7 +271,9 @@ static int xrx200_poll_rx(struct napi_st + + if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) { + ret = xrx200_hw_receive(ch); +- if (ret) ++ if (ret == XRX200_DMA_PACKET_IN_PROGRESS) ++ continue; ++ if (ret != XRX200_DMA_PACKET_COMPLETE) + return ret; + rx++; + } else { |