Commit 4e023b44 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

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

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: default avatarJakub Kicinski <kuba@kernel.org>
parents 87eee9c5 e0155935

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

+1 −1
Original line number Diff line number Diff line
@@ -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 */

drivers/net/ethernet/lantiq_xrx200.c

+40 −22
Original line number Diff line number Diff line
@@ -63,7 +63,11 @@ struct xrx200_chan { 


	struct napi_struct napi;

	struct ltq_dma_channel dma;



	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 @@ static int xrx200_dma_init(struct xrx200_priv *priv) 
	/* 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);