[Intel-wired-lan] [PATCH v1] igc: Add support for TSO
Sasha Neftin
sasha.neftin at intel.com
Sun Jan 5 12:20:53 UTC 2020
TCP segmentation offload allows a device to segment a single frame
into multiple frames with a data payload size specified in socket buffer.
As a result we can now send data approximately up to seven percents fast
than was previously possible on my system.
Signed-off-by: Sasha Neftin <sasha.neftin at intel.com>
---
drivers/net/ethernet/intel/igc/igc_defines.h | 4 +
drivers/net/ethernet/intel/igc/igc_main.c | 113 ++++++++++++++++++++++++++-
2 files changed, 116 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index 2121fc34e300..9e34b0969322 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -282,6 +282,10 @@
#define IGC_TXD_STAT_TC 0x00000004 /* Tx Underrun */
#define IGC_TXD_EXTCMD_TSTAMP 0x00000010 /* IEEE1588 Timestamp packet */
+/* IPSec Encrypt Enable */
+#define IGC_ADVTXD_L4LEN_SHIFT 8 /* Adv ctxt L4LEN shift */
+#define IGC_ADVTXD_MSS_SHIFT 16 /* Adv ctxt MSS shift */
+
/* Transmit Control */
#define IGC_TCTL_EN 0x00000002 /* enable Tx */
#define IGC_TCTL_PSP 0x00000008 /* pad short packets */
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 37d2d242c3a6..607bf89ecd71 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1000,6 +1000,10 @@ static u32 igc_tx_cmd_type(struct sk_buff *skb, u32 tx_flags)
IGC_ADVTXD_DCMD_DEXT |
IGC_ADVTXD_DCMD_IFCS;
+ /* set segmentation bits for TSO */
+ cmd_type |= IGC_SET_FLAG(tx_flags, IGC_TX_FLAGS_TSO,
+ (IGC_ADVTXD_DCMD_TSE));
+
/* set timestamp bit if present */
cmd_type |= IGC_SET_FLAG(tx_flags, IGC_TX_FLAGS_TSTAMP,
(IGC_ADVTXD_MAC_TSTAMP));
@@ -1171,6 +1175,100 @@ static int igc_tx_map(struct igc_ring *tx_ring,
return -1;
}
+static int igc_tso(struct igc_ring *tx_ring,
+ struct igc_tx_buffer *first,
+ u8 *hdr_len)
+{
+ u32 vlan_macip_lens, type_tucmd, mss_l4len_idx;
+ struct sk_buff *skb = first->skb;
+ union {
+ struct iphdr *v4;
+ struct ipv6hdr *v6;
+ unsigned char *hdr;
+ } ip;
+ union {
+ struct tcphdr *tcp;
+ struct udphdr *udp;
+ unsigned char *hdr;
+ } l4;
+ u32 paylen, l4_offset;
+ int err;
+
+ if (skb->ip_summed != CHECKSUM_PARTIAL)
+ return 0;
+
+ if (!skb_is_gso(skb))
+ return 0;
+
+ err = skb_cow_head(skb, 0);
+ if (err < 0)
+ return err;
+
+ ip.hdr = skb_network_header(skb);
+ l4.hdr = skb_checksum_start(skb);
+
+ /* ADV DTYP TUCMD MKRLOC/ISCSIHEDLEN */
+ type_tucmd = IGC_ADVTXD_TUCMD_L4T_TCP;
+
+ /* initialize outer IP header fields */
+ if (ip.v4->version == 4) {
+ unsigned char *csum_start = skb_checksum_start(skb);
+ unsigned char *trans_start = ip.hdr + (ip.v4->ihl * 4);
+
+ /* IP header will have to cancel out any data that
+ * is not a part of the outer IP header
+ */
+ ip.v4->check = csum_fold(csum_partial(trans_start,
+ csum_start - trans_start,
+ 0));
+ type_tucmd |= IGC_ADVTXD_TUCMD_IPV4;
+
+ ip.v4->tot_len = 0;
+ first->tx_flags |= IGC_TX_FLAGS_TSO |
+ IGC_TX_FLAGS_CSUM |
+ IGC_TX_FLAGS_IPV4;
+ } else {
+ ip.v6->payload_len = 0;
+ first->tx_flags |= IGC_TX_FLAGS_TSO |
+ IGC_TX_FLAGS_CSUM;
+ }
+
+ /* determine offset of inner transport header */
+ l4_offset = l4.hdr - skb->data;
+
+ /* remove payload length from inner checksum */
+ paylen = skb->len - l4_offset;
+ if (type_tucmd & IGC_ADVTXD_TUCMD_L4T_TCP) {
+ /* compute length of segmentation header */
+ *hdr_len = (l4.tcp->doff * 4) + l4_offset;
+ csum_replace_by_diff(&l4.tcp->check,
+ (__force __wsum)htonl(paylen));
+ } else {
+ /* compute length of segmentation header */
+ *hdr_len = sizeof(*l4.udp) + l4_offset;
+ csum_replace_by_diff(&l4.udp->check,
+ (__force __wsum)htonl(paylen));
+ }
+
+ /* update gso size and bytecount with header size */
+ first->gso_segs = skb_shinfo(skb)->gso_segs;
+ first->bytecount += (first->gso_segs - 1) * *hdr_len;
+
+ /* MSS L4LEN IDX */
+ mss_l4len_idx = (*hdr_len - l4_offset) << IGC_ADVTXD_L4LEN_SHIFT;
+ mss_l4len_idx |= skb_shinfo(skb)->gso_size << IGC_ADVTXD_MSS_SHIFT;
+
+ /* VLAN MACLEN IPLEN */
+ vlan_macip_lens = l4.hdr - ip.hdr;
+ vlan_macip_lens |= (ip.hdr - skb->data) << IGC_ADVTXD_MACLEN_SHIFT;
+ vlan_macip_lens |= first->tx_flags & IGC_TX_FLAGS_VLAN_MASK;
+
+ igc_tx_ctxtdesc(tx_ring, first, vlan_macip_lens,
+ type_tucmd, mss_l4len_idx);
+
+ return 1;
+}
+
static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb,
struct igc_ring *tx_ring)
{
@@ -1180,6 +1278,7 @@ static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb,
u32 tx_flags = 0;
unsigned short f;
u8 hdr_len = 0;
+ int tso = 0;
/* need: 1 descriptor per page * PAGE_SIZE/IGC_MAX_DATA_PER_TXD,
* + 1 desc for skb_headlen/IGC_MAX_DATA_PER_TXD,
@@ -1226,11 +1325,21 @@ static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb,
first->tx_flags = tx_flags;
first->protocol = protocol;
- igc_tx_csum(tx_ring, first);
+ tso = igc_tso(tx_ring, first, &hdr_len);
+ if (tso < 0)
+ goto out_drop;
+ else if (!tso)
+ igc_tx_csum(tx_ring, first);
igc_tx_map(tx_ring, first, hdr_len);
return NETDEV_TX_OK;
+
+out_drop:
+ dev_kfree_skb_any(first->skb);
+ first->skb = NULL;
+
+ return NETDEV_TX_OK;
}
static inline struct igc_ring *igc_tx_queue_mapping(struct igc_adapter *adapter,
@@ -4588,6 +4697,8 @@ static int igc_probe(struct pci_dev *pdev,
/* Add supported features to the features list*/
netdev->features |= NETIF_F_SG;
+ netdev->features |= NETIF_F_TSO;
+ netdev->features |= NETIF_F_TSO6;
netdev->features |= NETIF_F_RXCSUM;
netdev->features |= NETIF_F_HW_CSUM;
netdev->features |= NETIF_F_SCTP_CRC;
--
2.11.0
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