mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-22 23:12:32 +00:00
105 lines
3.1 KiB
Diff
105 lines
3.1 KiB
Diff
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 {
|