RDMA/cxgb4: Add module option to tweak delayed ack

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 19 insertions, 1 deletions

diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index 4185c3b0635..e7b08dca740 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -61,6 +61,10 @@ static char *states[] = {
         NULL,
 };
 
+static int dack_mode;
+module_param(dack_mode, int, 0644);
+MODULE_PARM_DESC(dack_mode, "Delayed ack mode (default=0)");
+
 int c4iw_max_read_depth = 8;
 module_param(c4iw_max_read_depth, int, 0644);
 MODULE_PARM_DESC(c4iw_max_read_depth, "Per-connection max ORD/IRD (default=8)");
@@ -474,6 +478,7 @@ static int send_connect(struct c4iw_ep *ep)
         cxgb4_best_mtu(ep->com.dev->rdev.lldi.mtus, ep->mtu, &mtu_idx);
         wscale = compute_wscale(rcv_win);
         opt0 = KEEP_ALIVE(1) |
+               DELACK(1) |
                WND_SCALE(wscale) |
                MSS_IDX(mtu_idx) |
                L2T_IDX(ep->l2t->idx) |
@@ -845,7 +850,9 @@ static int update_rx_credits(struct c4iw_ep *ep, u32 credits)
         INIT_TP_WR(req, ep->hwtid);
         OPCODE_TID(req) = cpu_to_be32(MK_OPCODE_TID(CPL_RX_DATA_ACK,
                                                     ep->hwtid));
-        req->credit_dack = cpu_to_be32(credits);
+        req->credit_dack = cpu_to_be32(credits | RX_FORCE_ACK(1) |
+                                       F_RX_DACK_CHANGE |
+                                       V_RX_DACK_MODE(dack_mode));
         set_wr_txq(skb, CPL_PRIORITY_ACK, ep->txq_idx);
         c4iw_ofld_send(&ep->com.dev->rdev, skb);
         return credits;
@@ -1264,6 +1271,7 @@ static void accept_cr(struct c4iw_ep *ep, __be32 peer_ip, struct sk_buff *skb,
         cxgb4_best_mtu(ep->com.dev->rdev.lldi.mtus, ep->mtu, &mtu_idx);
         wscale = compute_wscale(rcv_win);
         opt0 = KEEP_ALIVE(1) |
+               DELACK(1) |
                WND_SCALE(wscale) |
                MSS_IDX(mtu_idx) |
                L2T_IDX(ep->l2t->idx) |
diff --git a/drivers/infiniband/hw/cxgb4/t4fw_ri_api.h b/drivers/infiniband/hw/cxgb4/t4fw_ri_api.h
index fc706bd07fa..dc193c29267 100644
--- a/drivers/infiniband/hw/cxgb4/t4fw_ri_api.h
+++ b/drivers/infiniband/hw/cxgb4/t4fw_ri_api.h
@@ -826,4 +826,14 @@ struct ulptx_idata {
 #define S_ULPTX_NSGE    0
 #define M_ULPTX_NSGE    0xFFFF
 #define V_ULPTX_NSGE(x) ((x) << S_ULPTX_NSGE)
+
+#define S_RX_DACK_MODE    29
+#define M_RX_DACK_MODE    0x3
+#define V_RX_DACK_MODE(x) ((x) << S_RX_DACK_MODE)
+#define G_RX_DACK_MODE(x) (((x) >> S_RX_DACK_MODE) & M_RX_DACK_MODE)
+
+#define S_RX_DACK_CHANGE    31
+#define V_RX_DACK_CHANGE(x) ((x) << S_RX_DACK_CHANGE)
+#define F_RX_DACK_CHANGE    V_RX_DACK_CHANGE(1U)
+
 #endif /* _T4FW_RI_API_H_ */