[PATCH net-next 6/6] net: stmmac: Implement UDP Segmentation Offload

From: Jose Abreu
Date: Mon Nov 11 2019 - 09:43:08 EST


Implement the UDP Segmentation Offload feature in stmmac. This is only
available in GMAC4+ cores.

Signed-off-by: Jose Abreu <Jose.Abreu@xxxxxxxxxxxx>

---
Cc: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
Cc: Alexandre Torgue <alexandre.torgue@xxxxxx>
Cc: Jose Abreu <joabreu@xxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 32 ++++++++++++++++-------
1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index a2fac7772666..39b4efd521f9 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -36,6 +36,7 @@
#endif /* CONFIG_DEBUG_FS */
#include <linux/net_tstamp.h>
#include <linux/phylink.h>
+#include <linux/udp.h>
#include <net/pkt_cls.h>
#include "stmmac_ptp.h"
#include "stmmac.h"
@@ -2916,9 +2917,9 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
u32 queue = skb_get_queue_mapping(skb);
struct stmmac_tx_queue *tx_q;
unsigned int first_entry;
+ u8 proto_hdr_len, hdr;
int tmp_pay_len = 0;
u32 pay_len, mss;
- u8 proto_hdr_len;
dma_addr_t des;
bool has_vlan;
int i;
@@ -2926,7 +2927,13 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
tx_q = &priv->tx_queue[queue];

/* Compute header lengths */
- proto_hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
+ proto_hdr_len = skb_transport_offset(skb) + sizeof(struct udphdr);
+ hdr = sizeof(struct udphdr);
+ } else {
+ proto_hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
+ hdr = tcp_hdrlen(skb);
+ }

/* Desc availability based on threshold should be enough safe */
if (unlikely(stmmac_tx_avail(priv, queue) <
@@ -2956,8 +2963,8 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
}

if (netif_msg_tx_queued(priv)) {
- pr_info("%s: tcphdrlen %d, hdr_len %d, pay_len %d, mss %d\n",
- __func__, tcp_hdrlen(skb), proto_hdr_len, pay_len, mss);
+ pr_info("%s: hdrlen %d, hdr_len %d, pay_len %d, mss %d\n",
+ __func__, hdr, proto_hdr_len, pay_len, mss);
pr_info("\tskb->len %d, skb->data_len %d\n", skb->len,
skb->data_len);
}
@@ -3071,7 +3078,7 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
proto_hdr_len,
pay_len,
1, tx_q->tx_skbuff_dma[first_entry].last_segment,
- tcp_hdrlen(skb) / 4, (skb->len - proto_hdr_len));
+ hdr / 4, (skb->len - proto_hdr_len));

/* If context desc is used to change MSS */
if (mss_desc) {
@@ -3130,6 +3137,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
int i, csum_insertion = 0, is_jumbo = 0;
u32 queue = skb_get_queue_mapping(skb);
int nfrags = skb_shinfo(skb)->nr_frags;
+ int gso = skb_shinfo(skb)->gso_type;
struct dma_desc *desc, *first;
struct stmmac_tx_queue *tx_q;
unsigned int first_entry;
@@ -3145,7 +3153,9 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)

/* Manage oversized TCP frames for GMAC4 device */
if (skb_is_gso(skb) && priv->tso) {
- if (skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))
+ if (gso & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))
+ return stmmac_tso_xmit(skb, dev);
+ if (priv->plat->has_gmac4 && (gso & SKB_GSO_UDP_L4))
return stmmac_tso_xmit(skb, dev);
}

@@ -4036,11 +4046,13 @@ static int stmmac_setup_tc(struct net_device *ndev, enum tc_setup_type type,
static u16 stmmac_select_queue(struct net_device *dev, struct sk_buff *skb,
struct net_device *sb_dev)
{
- if (skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)) {
+ int gso = skb_shinfo(skb)->gso_type;
+
+ if (gso & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6 | SKB_GSO_UDP_L4)) {
/*
- * There is no way to determine the number of TSO
+ * There is no way to determine the number of TSO/USO
* capable Queues. Let's use always the Queue 0
- * because if TSO is supported then at least this
+ * because if TSO/USO is supported then at least this
* one will be capable.
*/
return 0;
@@ -4555,6 +4567,8 @@ int stmmac_dvr_probe(struct device *device,

if ((priv->plat->tso_en) && (priv->dma_cap.tsoen)) {
ndev->hw_features |= NETIF_F_TSO | NETIF_F_TSO6;
+ if (priv->plat->has_gmac4)
+ ndev->hw_features |= NETIF_F_GSO_UDP_L4;
priv->tso = true;
dev_info(priv->device, "TSO feature enabled\n");
}
--
2.7.4