[OpenWrt-Devel] [PATCH] [ 4/5] ramips: add xmit_more support
michael lee
igvtee at gmail.com
Tue Jun 2 09:06:44 EDT 2015
use pktgen to verify on rt3662. can improve transmit rate.
pkt_size 1500
burst 1 : 807Mb/sec
burst 8 : 984Mb/sec
pkt_size 60
burst 1 : 57Mb/sec
burst 8 : 236Mb/sec
Signed-off-by: michael lee <igvtee at gmail.com>
---
.../drivers/net/ethernet/ralink/ralink_soc_eth.c | 51 +++++++++++++---------
.../drivers/net/ethernet/ralink/ralink_soc_eth.h | 2 +
2 files changed, 33 insertions(+), 20 deletions(-)
diff --git a/target/linux/ramips/files/drivers/net/ethernet/ralink/ralink_soc_eth.c b/target/linux/ramips/files/drivers/net/ethernet/ralink/ralink_soc_eth.c
index b2304bb..4b39825 100644
--- a/target/linux/ramips/files/drivers/net/ethernet/ralink/ralink_soc_eth.c
+++ b/target/linux/ramips/files/drivers/net/ethernet/ralink/ralink_soc_eth.c
@@ -337,6 +337,8 @@ static int fe_alloc_tx(struct fe_priv *priv)
struct fe_tx_ring *ring = &priv->tx_ring;
ring->tx_free_idx = 0;
+ ring->tx_next_idx = 0;
+ ring->tx_thresh = max((unsigned long)ring->tx_ring_size >> 2, MAX_SKB_FRAGS);
ring->tx_buf = kcalloc(ring->tx_ring_size, sizeof(*ring->tx_buf),
GFP_KERNEL);
@@ -525,8 +527,16 @@ static int fe_vlan_rx_kill_vid(struct net_device *dev,
return 0;
}
+static inline u32 fe_empty_txd(struct fe_tx_ring *ring)
+{
+ barrier();
+ return (u32)(ring->tx_ring_size -
+ ((ring->tx_next_idx - ring->tx_free_idx) &
+ (ring->tx_ring_size - 1)));
+}
+
static int fe_tx_map_dma(struct sk_buff *skb, struct net_device *dev,
- int idx, int tx_num, struct fe_tx_ring *ring)
+ int tx_num, struct fe_tx_ring *ring)
{
struct fe_priv *priv = netdev_priv(dev);
struct skb_frag_struct *frag;
@@ -537,7 +547,7 @@ static int fe_tx_map_dma(struct sk_buff *skb, struct net_device *dev,
u32 def_txd4;
int i, j, k, frag_size, frag_map_size, offset;
- tx_buf = &ring->tx_buf[idx];
+ tx_buf = &ring->tx_buf[ring->tx_next_idx];
memset(tx_buf, 0, sizeof(*tx_buf));
memset(&txd, 0, sizeof(txd));
nr_frags = skb_shinfo(skb)->nr_frags;
@@ -589,7 +599,7 @@ static int fe_tx_map_dma(struct sk_buff *skb, struct net_device *dev,
dma_unmap_len_set(tx_buf, dma_len0, skb_headlen(skb));
/* TX SG offload */
- j = idx;
+ j = ring->tx_next_idx;
k = 0;
for (i = 0; i < nr_frags; i++) {
offset = 0;
@@ -649,14 +659,22 @@ static int fe_tx_map_dma(struct sk_buff *skb, struct net_device *dev,
netdev_sent_queue(dev, skb->len);
skb_tx_timestamp(skb);
- j = NEXT_TX_DESP_IDX(j);
+ ring->tx_next_idx = NEXT_TX_DESP_IDX(j);
wmb();
- fe_reg_w32(j, FE_REG_TX_CTX_IDX0);
+ if (unlikely(fe_empty_txd(ring) <= ring->tx_thresh)) {
+ netif_stop_queue(dev);
+ smp_mb();
+ if (unlikely(fe_empty_txd(ring) > ring->tx_thresh))
+ netif_wake_queue(dev);
+ }
+
+ if (netif_xmit_stopped(netdev_get_tx_queue(dev, 0)) || !skb->xmit_more)
+ fe_reg_w32(ring->tx_next_idx, FE_REG_TX_CTX_IDX0);
return 0;
err_dma:
- j = idx;
+ j = ring->tx_next_idx;
for (i = 0; i < tx_num; i++) {
ptxd = &ring->tx_dma[j];
tx_buf = &ring->tx_buf[j];
@@ -703,12 +721,6 @@ static inline int fe_skb_padto(struct sk_buff *skb, struct fe_priv *priv) {
return ret;
}
-static inline u32 fe_empty_txd(struct fe_tx_ring *ring, u32 tx_fill_idx)
-{
- return (u32)(ring->tx_ring_size - ((tx_fill_idx - ring->tx_free_idx) &
- (ring->tx_ring_size - 1)));
-}
-
static inline int fe_cal_txd_req(struct sk_buff *skb)
{
int i, nfrags;
@@ -732,7 +744,6 @@ static int fe_start_xmit(struct sk_buff *skb, struct net_device *dev)
struct fe_priv *priv = netdev_priv(dev);
struct fe_tx_ring *ring = &priv->tx_ring;
struct net_device_stats *stats = &dev->stats;
- u32 tx;
int tx_num;
int len = skb->len;
@@ -742,8 +753,7 @@ static int fe_start_xmit(struct sk_buff *skb, struct net_device *dev)
}
tx_num = fe_cal_txd_req(skb);
- tx = fe_reg_r32(FE_REG_TX_CTX_IDX0);
- if (unlikely(fe_empty_txd(ring, tx) <= tx_num))
+ if (unlikely(fe_empty_txd(ring) <= tx_num))
{
netif_stop_queue(dev);
netif_err(priv, tx_queued,dev,
@@ -751,7 +761,7 @@ static int fe_start_xmit(struct sk_buff *skb, struct net_device *dev)
return NETDEV_TX_BUSY;
}
- if (fe_tx_map_dma(skb, dev, tx, tx_num, ring) < 0) {
+ if (fe_tx_map_dma(skb, dev, tx_num, ring) < 0) {
stats->tx_dropped++;
} else {
stats->tx_packets++;
@@ -916,10 +926,10 @@ static int fe_poll_tx(struct fe_priv *priv, int budget, u32 tx_intr,
if (done) {
netdev_completed_queue(netdev, done, bytes_compl);
+ smp_mb();
if (unlikely(netif_queue_stopped(netdev) &&
- netif_carrier_ok(netdev))) {
+ (fe_empty_txd(ring) > ring->tx_thresh)))
netif_wake_queue(netdev);
- }
}
return done;
@@ -990,12 +1000,13 @@ static void fe_tx_timeout(struct net_device *dev)
netif_info(priv, drv, dev, "dma_cfg:%08x\n",
fe_reg_r32(FE_REG_PDMA_GLO_CFG));
netif_info(priv, drv, dev, "tx_ring=%d, " \
- "base=%08x, max=%u, ctx=%u, dtx=%u, fdx=%d\n", 0,
+ "base=%08x, max=%u, ctx=%u, dtx=%u, fdx=%hu, next=%hu\n", 0,
fe_reg_r32(FE_REG_TX_BASE_PTR0),
fe_reg_r32(FE_REG_TX_MAX_CNT0),
fe_reg_r32(FE_REG_TX_CTX_IDX0),
fe_reg_r32(FE_REG_TX_DTX_IDX0),
- ring->tx_free_idx
+ ring->tx_free_idx,
+ ring->tx_next_idx
);
netif_info(priv, drv, dev, "rx_ring=%d, " \
"base=%08x, max=%u, calc=%u, drx=%u\n", 0,
diff --git a/target/linux/ramips/files/drivers/net/ethernet/ralink/ralink_soc_eth.h b/target/linux/ramips/files/drivers/net/ethernet/ralink/ralink_soc_eth.h
index 6614c76..5d4220f 100644
--- a/target/linux/ramips/files/drivers/net/ethernet/ralink/ralink_soc_eth.h
+++ b/target/linux/ramips/files/drivers/net/ethernet/ralink/ralink_soc_eth.h
@@ -461,6 +461,8 @@ struct fe_tx_ring
dma_addr_t tx_phys;
u16 tx_ring_size;
u16 tx_free_idx;
+ u16 tx_next_idx;
+ u16 tx_thresh;
};
struct fe_priv
--
2.0.5
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