iw_cxgb4: Choose appropriate hw mtu index and ISS for iWARP connections
Select the appropriate hw mtu index and initial sequence number to optimize
hw memory performance.
Add new cxgb4_best_aligned_mtu() which allows callers to provide enough
information to be used to [possibly] select an MTU which will result in the
TCP Data Segment Size (AKA Maximum Segment Size) to be an aligned value.
If an RTR message exhange is required, then align the ISS to 8B - 1 + 4, so
that after the SYN the send seqno will align on a 4B boundary. The RTR
message exchange will leave the send seqno aligned on an 8B boundary.
If an RTR is not required, then align the ISS to 8B - 1. The goal is
to have the send seqno be 8B aligned when we send the first FPDU.
Based on original work by Casey Leedom <leeedom@chelsio.com> and
Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Casey Leedom <leedom@chelsio.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.h b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.h
index 87af314..55e9daf 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.h
@@ -276,6 +276,11 @@
unsigned int cxgb4_port_idx(const struct net_device *dev);
unsigned int cxgb4_best_mtu(const unsigned short *mtus, unsigned short mtu,
unsigned int *idx);
+unsigned int cxgb4_best_aligned_mtu(const unsigned short *mtus,
+ unsigned short header_size,
+ unsigned short data_size_max,
+ unsigned short data_size_align,
+ unsigned int *mtu_idxp);
void cxgb4_get_tcp_stats(struct pci_dev *pdev, struct tp_tcp_stats *v4,
struct tp_tcp_stats *v6);
void cxgb4_iscsi_init(struct net_device *dev, unsigned int tag_mask,