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Merge branch 'net-lantiq_xrx200-improve-ethernet-performance'

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Aleksander Jan Bajkowski says:

====================
net: lantiq_xrx200: improve ethernet performance

This patchset improves Ethernet performance by 15%.

NAT Performance results on BT Home Hub 5A (kernel 5.10.89, mtu 1500):

	Down		Up
Before	539 Mbps	599 Mbps
After	624 Mbps	695 Mbps
====================

Link: https://lore.kernel.org/r/20220104151144.181736-1-olek2@wp.pl
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski 2022-01-05 17:18:07 -08:00
commit 4e023b44d5
2 changed files with 41 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/mips/include/asm/mach-lantiq/xway/xway_dma.h
View File

@ -8,7 +8,7 @@
#define LTQ_DMA_H__
#define LTQ_DESC_SIZE 0x08 /* each descriptor is 64bit */
#define LTQ_DESC_NUM 0x40 /* 64 descriptors / channel */
#define LTQ_DESC_NUM 0xC0 /* 192 descriptors / channel */
#define LTQ_DMA_OWN BIT(31) /* owner bit */
#define LTQ_DMA_C BIT(30) /* complete bit */

62
drivers/net/ethernet/lantiq_xrx200.c
View File

@ -63,7 +63,11 @@ struct xrx200_chan {
struct napi_struct napi;
struct ltq_dma_channel dma;
struct sk_buff *skb[LTQ_DESC_NUM];
union {
struct sk_buff *skb[LTQ_DESC_NUM];
void *rx_buff[LTQ_DESC_NUM];
};
struct sk_buff *skb_head;
struct sk_buff *skb_tail;
@ -78,6 +82,7 @@ struct xrx200_priv {
struct xrx200_chan chan_rx;
u16 rx_buf_size;
u16 rx_skb_size;
struct net_device *net_dev;
struct device *dev;
@ -115,6 +120,12 @@ static int xrx200_buffer_size(int mtu)
return round_up(xrx200_max_frame_len(mtu), 4 * XRX200_DMA_BURST_LEN);
}
static int xrx200_skb_size(u16 buf_size)
{
return SKB_DATA_ALIGN(buf_size + NET_SKB_PAD + NET_IP_ALIGN) +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
}
/* drop all the packets from the DMA ring */
static void xrx200_flush_dma(struct xrx200_chan *ch)
{
@ -173,30 +184,29 @@ static int xrx200_close(struct net_device *net_dev)
return 0;
}
static int xrx200_alloc_skb(struct xrx200_chan *ch)
static int xrx200_alloc_buf(struct xrx200_chan *ch, void *(*alloc)(unsigned int size))
{
struct sk_buff *skb = ch->skb[ch->dma.desc];
void *buf = ch->rx_buff[ch->dma.desc];
struct xrx200_priv *priv = ch->priv;
dma_addr_t mapping;
int ret = 0;
ch->skb[ch->dma.desc] = netdev_alloc_skb_ip_align(priv->net_dev,
priv->rx_buf_size);
if (!ch->skb[ch->dma.desc]) {
ch->rx_buff[ch->dma.desc] = alloc(priv->rx_skb_size);
if (!ch->rx_buff[ch->dma.desc]) {
ret = -ENOMEM;
goto skip;
}
mapping = dma_map_single(priv->dev, ch->skb[ch->dma.desc]->data,
mapping = dma_map_single(priv->dev, ch->rx_buff[ch->dma.desc],
priv->rx_buf_size, DMA_FROM_DEVICE);
if (unlikely(dma_mapping_error(priv->dev, mapping))) {
dev_kfree_skb_any(ch->skb[ch->dma.desc]);
ch->skb[ch->dma.desc] = skb;
skb_free_frag(ch->rx_buff[ch->dma.desc]);
ch->rx_buff[ch->dma.desc] = buf;
ret = -ENOMEM;
goto skip;
}
ch->dma.desc_base[ch->dma.desc].addr = mapping;
ch->dma.desc_base[ch->dma.desc].addr = mapping + NET_SKB_PAD + NET_IP_ALIGN;
/* Make sure the address is written before we give it to HW */
wmb();
skip:
@ -210,13 +220,14 @@ static int xrx200_hw_receive(struct xrx200_chan *ch)
{
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];
void *buf = ch->rx_buff[ch->dma.desc];
u32 ctl = desc->ctl;
int len = (ctl & LTQ_DMA_SIZE_MASK);
struct net_device *net_dev = priv->net_dev;
struct sk_buff *skb;
int ret;
ret = xrx200_alloc_skb(ch);
ret = xrx200_alloc_buf(ch, napi_alloc_frag);
ch->dma.desc++;
ch->dma.desc %= LTQ_DESC_NUM;
@ -227,19 +238,21 @@ static int xrx200_hw_receive(struct xrx200_chan *ch)
return ret;
}
skb = build_skb(buf, priv->rx_skb_size);
skb_reserve(skb, NET_SKB_PAD);
skb_put(skb, len);
/* add buffers to skb via skb->frag_list */
if (ctl & LTQ_DMA_SOP) {
ch->skb_head = skb;
ch->skb_tail = skb;
skb_reserve(skb, NET_IP_ALIGN);
} 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;
@ -395,12 +408,13 @@ xrx200_change_mtu(struct net_device *net_dev, int new_mtu)
struct xrx200_chan *ch_rx = &priv->chan_rx;
int old_mtu = net_dev->mtu;
bool running = false;
struct sk_buff *skb;
void *buff;
int curr_desc;
int ret = 0;
net_dev->mtu = new_mtu;
priv->rx_buf_size = xrx200_buffer_size(new_mtu);
priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
if (new_mtu <= old_mtu)
return ret;
@ -416,14 +430,15 @@ xrx200_change_mtu(struct net_device *net_dev, int new_mtu)
for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
ch_rx->dma.desc++) {
skb = ch_rx->skb[ch_rx->dma.desc];
ret = xrx200_alloc_skb(ch_rx);
buff = ch_rx->rx_buff[ch_rx->dma.desc];
ret = xrx200_alloc_buf(ch_rx, netdev_alloc_frag);
if (ret) {
net_dev->mtu = old_mtu;
priv->rx_buf_size = xrx200_buffer_size(old_mtu);
priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
break;
}
dev_kfree_skb_any(skb);
skb_free_frag(buff);
}
ch_rx->dma.desc = curr_desc;
@ -476,7 +491,7 @@ static int xrx200_dma_init(struct xrx200_priv *priv)
ltq_dma_alloc_rx(&ch_rx->dma);
for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
ch_rx->dma.desc++) {
ret = xrx200_alloc_skb(ch_rx);
ret = xrx200_alloc_buf(ch_rx, netdev_alloc_frag);
if (ret)
goto rx_free;
}
@ -511,7 +526,7 @@ rx_ring_free:
/* free the allocated RX ring */
for (i = 0; i < LTQ_DESC_NUM; i++) {
if (priv->chan_rx.skb[i])
dev_kfree_skb_any(priv->chan_rx.skb[i]);
skb_free_frag(priv->chan_rx.rx_buff[i]);
}
rx_free:
@ -528,7 +543,7 @@ static void xrx200_hw_cleanup(struct xrx200_priv *priv)
/* free the allocated RX ring */
for (i = 0; i < LTQ_DESC_NUM; i++)
dev_kfree_skb_any(priv->chan_rx.skb[i]);
skb_free_frag(priv->chan_rx.rx_buff[i]);
}
static int xrx200_probe(struct platform_device *pdev)
@ -553,6 +568,7 @@ static int xrx200_probe(struct platform_device *pdev)
net_dev->min_mtu = ETH_ZLEN;
net_dev->max_mtu = XRX200_DMA_DATA_LEN - xrx200_max_frame_len(0);
priv->rx_buf_size = xrx200_buffer_size(ETH_DATA_LEN);
priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
/* load the memory ranges */
priv->pmac_reg = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
@ -597,8 +613,10 @@ static int xrx200_probe(struct platform_device *pdev)
PMAC_HD_CTL);
/* setup NAPI */
netif_napi_add(net_dev, &priv->chan_rx.napi, xrx200_poll_rx, 32);
netif_tx_napi_add(net_dev, &priv->chan_tx.napi, xrx200_tx_housekeeping, 32);
netif_napi_add(net_dev, &priv->chan_rx.napi, xrx200_poll_rx,
NAPI_POLL_WEIGHT);
netif_tx_napi_add(net_dev, &priv->chan_tx.napi, xrx200_tx_housekeeping,
NAPI_POLL_WEIGHT);
platform_set_drvdata(pdev, priv);