[PATCH net-next 08/12] r8152: support TSO

From: Hayes Wang
Date: Tue Mar 04 2014 - 07:04:07 EST


Support scatter gather and TSO.

Adjust the tx checksum function and set the max gso size to fix the
size of the tx aggregation buffer.

Signed-off-by: Hayes Wang <hayeswang@xxxxxxxxxxx>
---
drivers/net/usb/r8152.c | 133 +++++++++++++++++++++++++++++++++++++-----------
1 file changed, 103 insertions(+), 30 deletions(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 5fdf0af..774a19a 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -23,7 +23,7 @@
#include <linux/ipv6.h>

/* Version Information */
-#define DRIVER_VERSION "v1.05.0 (2014/02/18)"
+#define DRIVER_VERSION "v1.06.0 (2014/03/03)"
#define DRIVER_AUTHOR "Realtek linux nic maintainers <nic_swsd@xxxxxxxxxxx>"
#define DRIVER_DESC "Realtek RTL8152/RTL8153 Based USB Ethernet Adapters"
#define MODULENAME "r8152"
@@ -490,13 +490,18 @@ struct tx_desc {
__le32 opts1;
#define TX_FS (1 << 31) /* First segment of a packet */
#define TX_LS (1 << 30) /* Final segment of a packet */
-#define TX_LEN_MASK 0x3ffff
+#define GTSENDV4 (1 << 28)
+#define GTTCPHO_SHIFT 18
+#define TX_LEN_MAX 0x3ffffU

__le32 opts2;
#define UDP_CS (1 << 31) /* Calculate UDP/IP checksum */
#define TCP_CS (1 << 30) /* Calculate TCP/IP checksum */
#define IPV4_CS (1 << 29) /* Calculate IPv4 checksum */
#define IPV6_CS (1 << 28) /* Calculate IPv6 checksum */
+#define MSS_SHIFT 17
+#define MSS_MAX 0x7ffU
+#define TCPHO_SHIFT 17
};

struct r8152;
@@ -563,12 +568,21 @@ enum rtl_version {
RTL_VER_MAX
};

+enum tx_csum_stat {
+ TX_CSUM_SUCCESS = 0,
+ TX_CSUM_TSO,
+ TX_CSUM_NONE
+};
+
/* Maximum number of multicast addresses to filter (vs. Rx-all-multicast).
* The RTL chips use a 64 element hash table based on the Ethernet CRC.
*/
static const int multicast_filter_limit = 32;
static unsigned int rx_buf_sz = 16384;

+#define RTL_LIMITED_TSO_SIZE (rx_buf_sz - sizeof(struct tx_desc) - \
+ VLAN_ETH_HLEN - VLAN_HLEN)
+
static
int get_registers(struct r8152 *tp, u16 value, u16 index, u16 size, void *data)
{
@@ -1295,24 +1309,46 @@ static struct tx_agg *r8152_get_tx_agg(struct r8152 *tp)
return agg;
}

-static void
-r8152_tx_csum(struct r8152 *tp, struct tx_desc *desc, struct sk_buff *skb)
+static inline __be16 get_protocol(struct sk_buff *skb)
{
- memset(desc, 0, sizeof(*desc));
+ __be16 protocol;

- desc->opts1 = cpu_to_le32((skb->len & TX_LEN_MASK) | TX_FS | TX_LS);
+ if (skb->protocol == htons(ETH_P_8021Q))
+ protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
+ else
+ protocol = skb->protocol;

- if (skb->ip_summed == CHECKSUM_PARTIAL) {
- __be16 protocol;
- u8 ip_protocol;
- u32 opts2 = 0;
+ return protocol;
+}

- if (skb->protocol == htons(ETH_P_8021Q))
- protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
- else
- protocol = skb->protocol;
+static int r8152_tx_csum(struct r8152 *tp, struct tx_desc *desc,
+ struct sk_buff *skb, u32 len, u32 transport_offset)
+{
+ u32 mss = skb_shinfo(skb)->gso_size;
+ u32 opts1, opts2 = 0;
+ int ret = TX_CSUM_SUCCESS;
+
+ WARN_ON_ONCE(len > TX_LEN_MAX);
+
+ opts1 = len | TX_FS | TX_LS;
+
+ if (mss) {
+ switch (get_protocol(skb)) {
+ case htons(ETH_P_IP):
+ opts1 |= GTSENDV4;
+ break;

- switch (protocol) {
+ default:
+ WARN_ON_ONCE(1);
+ break;
+ }
+
+ opts1 |= transport_offset << GTTCPHO_SHIFT;
+ opts2 |= min(mss, MSS_MAX) << MSS_SHIFT;
+ } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ u8 ip_protocol;
+
+ switch (get_protocol(skb)) {
case htons(ETH_P_IP):
opts2 |= IPV4_CS;
ip_protocol = ip_hdr(skb)->protocol;
@@ -1328,17 +1364,44 @@ r8152_tx_csum(struct r8152 *tp, struct tx_desc *desc, struct sk_buff *skb)
break;
}

- if (ip_protocol == IPPROTO_TCP) {
+ if (ip_protocol == IPPROTO_TCP)
opts2 |= TCP_CS;
- opts2 |= (skb_transport_offset(skb) & 0x7fff) << 17;
- } else if (ip_protocol == IPPROTO_UDP) {
+ else if (ip_protocol == IPPROTO_UDP)
opts2 |= UDP_CS;
- } else {
+ else
WARN_ON_ONCE(1);
- }

- desc->opts2 = cpu_to_le32(opts2);
+ opts2 |= transport_offset << TCPHO_SHIFT;
+ }
+
+ desc->opts2 = cpu_to_le32(opts2);
+ desc->opts1 = cpu_to_le32(opts1);
+
+ return ret;
+}
+
+static u32 r8152_xmit_frags(struct r8152 *tp, struct sk_buff *skb, u8 *data)
+{
+ struct skb_shared_info *info = skb_shinfo(skb);
+ unsigned int cur_frag;
+ u32 total = skb_headlen(skb);
+
+ memcpy(data, skb->data, total);
+ data += total;
+
+ for (cur_frag = 0; cur_frag < info->nr_frags; cur_frag++) {
+ const skb_frag_t *frag = info->frags + cur_frag;
+ void *addr;
+ u32 len;
+
+ len = skb_frag_size(frag);
+ addr = skb_frag_address(frag);
+ memcpy(data, addr, len);
+ data += len;
+ total += len;
}
+
+ return total;
}

static int r8152_tx_agg_fill(struct r8152 *tp, struct tx_agg *agg)
@@ -1360,29 +1423,36 @@ static int r8152_tx_agg_fill(struct r8152 *tp, struct tx_agg *agg)
struct tx_desc *tx_desc;
struct sk_buff *skb;
unsigned int len;
+ u32 offset;

skb = __skb_dequeue(&skb_head);
if (!skb)
break;

- remain -= sizeof(*tx_desc);
- len = skb->len;
- if (remain < len) {
+ len = skb->len + sizeof(*tx_desc);
+
+ if (len > remain) {
__skb_queue_head(&skb_head, skb);
break;
}

tx_data = tx_agg_align(tx_data);
tx_desc = (struct tx_desc *)tx_data;
+
+ offset = (u32)skb_transport_offset(skb);
+
+ r8152_tx_csum(tp, tx_desc, skb, skb->len, offset);
+
tx_data += sizeof(*tx_desc);

- r8152_tx_csum(tp, tx_desc, skb);
- memcpy(tx_data, skb->data, len);
- agg->skb_num++;
+ len = r8152_xmit_frags(tp, skb, tx_data);
+
+ tx_data += len;
agg->skb_len += len;
+ agg->skb_num++;
+
dev_kfree_skb_any(skb);

- tx_data += len;
remain = rx_buf_sz - (int)(tx_agg_align(tx_data) - agg->head);
}

@@ -3149,10 +3219,13 @@ static int rtl8152_probe(struct usb_interface *intf,
netdev->netdev_ops = &rtl8152_netdev_ops;
netdev->watchdog_timeo = RTL8152_TX_TIMEOUT;

- netdev->features |= NETIF_F_RXCSUM | NETIF_F_IP_CSUM;
- netdev->hw_features = NETIF_F_RXCSUM | NETIF_F_IP_CSUM;
+ netdev->features |= NETIF_F_RXCSUM | NETIF_F_IP_CSUM | NETIF_F_SG |
+ NETIF_F_TSO;
+ netdev->hw_features = NETIF_F_RXCSUM | NETIF_F_IP_CSUM | NETIF_F_SG |
+ NETIF_F_TSO;

SET_ETHTOOL_OPS(netdev, &ops);
+ netif_set_gso_max_size(netdev, RTL_LIMITED_TSO_SIZE);

tp->mii.dev = netdev;
tp->mii.mdio_read = read_mii_word;
--
1.8.4.2

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