Skip to content

Commit

Permalink
lantiq: backport latest upstream patches
Browse files Browse the repository at this point in the history 
This patch includes a series of performance improvements. All patches
were accepted and should land in 5.17.
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

Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
  • Loading branch information
@abajk @hauke
abajk authored and hauke committed Jan 16, 2022
1 parent 255268c commit 7e484b9
Show file tree
Hide file tree
Showing 3 changed files with 266 additions and 0 deletions.
28 changes: 28 additions & 0 deletions target/linux/lantiq/patches-5.10/0713-MIPS-lantiq-dma-increase-descritor-count.patch
View file
@@ -0,0 +1,28 @@
From 5112e9234bbb89f8dd15c983206bd9107b8436d5 Mon Sep 17 00:00:00 2001
From: Aleksander Jan Bajkowski <olek2@wp.pl>
Date: Tue, 4 Jan 2022 16:11:42 +0100
Subject: [PATCH 713/715] MIPS: lantiq: dma: increase descritor count

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

Down Up
Before 539 Mbps 599 Mbps
After 545 Mbps 625 Mbps

Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
arch/mips/include/asm/mach-lantiq/xway/xway_dma.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/include/asm/mach-lantiq/xway/xway_dma.h
+++ b/arch/mips/include/asm/mach-lantiq/xway/xway_dma.h
@@ -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 */
32 changes: 32 additions & 0 deletions target/linux/lantiq/patches-5.10/0714-net-lantiq_xrx200-increase-napi-poll-weigth.patch
View file
@@ -0,0 +1,32 @@
From 768818d772d5d4ddc0c7eb2e62848929270ab7a3 Mon Sep 17 00:00:00 2001
From: Aleksander Jan Bajkowski <olek2@wp.pl>
Date: Tue, 4 Jan 2022 16:11:43 +0100
Subject: [PATCH 714/715] net: lantiq_xrx200: increase napi poll weigth

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

Down Up
Before 545 Mbps 625 Mbps
After 577 Mbps 648 Mbps

Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
drivers/net/ethernet/lantiq_xrx200.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/lantiq_xrx200.c
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -606,8 +606,10 @@ static int xrx200_probe(struct platform_
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);

206 changes: 206 additions & 0 deletions target/linux/lantiq/patches-5.10/0715-net-lantiq_xrx200-convert-to-build_skb.patch
View file
@@ -0,0 +1,206 @@
From e015593573b3e3f74bd8a63c05fa92902194a354 Mon Sep 17 00:00:00 2001
From: Aleksander Jan Bajkowski <olek2@wp.pl>
Date: Tue, 4 Jan 2022 16:11:44 +0100
Subject: [PATCH 715/715] net: lantiq_xrx200: convert to build_skb

We can increase the efficiency of rx path by using buffers to receive
packets then build SKBs around them just before passing into the network
stack. In contrast, preallocating SKBs too early reduces CPU cache
efficiency.

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

Down Up
Before 577 Mbps 648 Mbps
After 624 Mbps 695 Mbps

Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
drivers/net/ethernet/lantiq_xrx200.c | 56 ++++++++++++++++++----------
1 file changed, 36 insertions(+), 20 deletions(-)

--- a/drivers/net/ethernet/lantiq_xrx200.c
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -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_devic
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 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];
+ 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 xrx2
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
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

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
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 xrx

/* 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)
@@ -554,6 +569,7 @@ static int xrx200_probe(struct platform_
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 */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

0 comments on commit 7e484b9

Please sign in to comment.