net: lantiq: configure the burst length in ethernet drivers

Configure the burst length in Ethernet drivers. This improves
Ethernet performance by 58%. According to the vendor BSP,
8W burst length is supported by ar9 and newer SoCs.

The NAT benchmark results on xRX200 (Down/Up):
* 2W: 330 Mb/s
* 4W: 432 Mb/s    372 Mb/s
* 8W: 520 Mb/s    389 Mb/s

Tested on xRX200 and xRX330.

Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Aleksander Jan Bajkowski 2021-09-14 23:21:02 +02:00 committed by David S. Miller
parent 49293bbc50
commit 14d4e308e0
2 changed files with 36 additions and 6 deletions

View File

@ -96,6 +96,9 @@ struct ltq_etop_priv {
struct ltq_etop_chan ch[MAX_DMA_CHAN];
int tx_free[MAX_DMA_CHAN >> 1];
int tx_burst_len;
int rx_burst_len;
spinlock_t lock;
};
@ -259,7 +262,7 @@ ltq_etop_hw_init(struct net_device *dev)
/* enable crc generation */
ltq_etop_w32(PPE32_CGEN, LQ_PPE32_ENET_MAC_CFG);
ltq_dma_init_port(DMA_PORT_ETOP);
ltq_dma_init_port(DMA_PORT_ETOP, priv->tx_burst_len, rx_burst_len);
for (i = 0; i < MAX_DMA_CHAN; i++) {
int irq = LTQ_DMA_CH0_INT + i;
@ -472,8 +475,8 @@ ltq_etop_tx(struct sk_buff *skb, struct net_device *dev)
return NETDEV_TX_BUSY;
}
/* dma needs to start on a 16 byte aligned address */
byte_offset = CPHYSADDR(skb->data) % 16;
/* dma needs to start on a burst length value aligned address */
byte_offset = CPHYSADDR(skb->data) % (priv->tx_burst_len * 4);
ch->skb[ch->dma.desc] = skb;
netif_trans_update(dev);
@ -667,6 +670,18 @@ ltq_etop_probe(struct platform_device *pdev)
spin_lock_init(&priv->lock);
SET_NETDEV_DEV(dev, &pdev->dev);
err = device_property_read_u32(&pdev->dev, "lantiq,tx-burst-length", &priv->tx_burst_len);
if (err < 0) {
dev_err(&pdev->dev, "unable to read tx-burst-length property\n");
return err;
}
err = device_property_read_u32(&pdev->dev, "lantiq,rx-burst-length", &priv->rx_burst_len);
if (err < 0) {
dev_err(&pdev->dev, "unable to read rx-burst-length property\n");
return err;
}
for (i = 0; i < MAX_DMA_CHAN; i++) {
if (IS_TX(i))
netif_napi_add(dev, &priv->ch[i].napi,

View File

@ -71,6 +71,9 @@ struct xrx200_priv {
struct net_device *net_dev;
struct device *dev;
int tx_burst_len;
int rx_burst_len;
__iomem void *pmac_reg;
};
@ -316,8 +319,8 @@ static netdev_tx_t xrx200_start_xmit(struct sk_buff *skb,
if (unlikely(dma_mapping_error(priv->dev, mapping)))
goto err_drop;
/* dma needs to start on a 16 byte aligned address */
byte_offset = mapping % 16;
/* dma needs to start on a burst length value aligned address */
byte_offset = mapping % (priv->tx_burst_len * 4);
desc->addr = mapping - byte_offset;
/* Make sure the address is written before we give it to HW */
@ -369,7 +372,7 @@ static int xrx200_dma_init(struct xrx200_priv *priv)
int ret = 0;
int i;
ltq_dma_init_port(DMA_PORT_ETOP);
ltq_dma_init_port(DMA_PORT_ETOP, priv->tx_burst_len, rx_burst_len);
ch_rx->dma.nr = XRX200_DMA_RX;
ch_rx->dma.dev = priv->dev;
@ -478,6 +481,18 @@ static int xrx200_probe(struct platform_device *pdev)
if (err)
eth_hw_addr_random(net_dev);
err = device_property_read_u32(dev, "lantiq,tx-burst-length", &priv->tx_burst_len);
if (err < 0) {
dev_err(dev, "unable to read tx-burst-length property\n");
return err;
}
err = device_property_read_u32(dev, "lantiq,rx-burst-length", &priv->rx_burst_len);
if (err < 0) {
dev_err(dev, "unable to read rx-burst-length property\n");
return err;
}
/* bring up the dma engine and IP core */
err = xrx200_dma_init(priv);
if (err)