5 files changed, 57 insertions, 18 deletions

diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 16181d655854..c7007c45889a 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -87,6 +87,7 @@ struct cm_port {
 struct cm_device {
         struct list_head list;
         struct ib_device *device;
+        u8 ack_delay;
         struct cm_port port[0];
 };
 
@@ -95,7 +96,7 @@ struct cm_av {
         union ib_gid dgid;
         struct ib_ah_attr ah_attr;
         u16 pkey_index;
-        u8 packet_life_time;
+        u8 timeout;
 };
 
 struct cm_work {
@@ -154,6 +155,7 @@ struct cm_id_private {
         u8 retry_count;
         u8 rnr_retry_count;
         u8 service_timeout;
+        u8 target_ack_delay;
 
         struct list_head work_list;
         atomic_t work_count;
@@ -293,7 +295,7 @@ static int cm_init_av_by_path(struct ib_sa_path_rec *path, struct cm_av *av)
         av->port = port;
         ib_init_ah_from_path(cm_dev->device, port->port_num, path,
                              &av->ah_attr);
-        av->packet_life_time = path->packet_life_time;
+        av->timeout = path->packet_life_time + 1;
         return 0;
 }
 
@@ -643,6 +645,25 @@ static inline int cm_convert_to_ms(int iba_time)
         return 1 << max(iba_time - 8, 0);
 }
 
+/*
+ * calculate: 4.096x2^ack_timeout = 4.096x2^ack_delay + 2x4.096x2^life_time
+ * Because of how ack_timeout is stored, adding one doubles the timeout.
+ * To avoid large timeouts, select the max(ack_delay, life_time + 1), and
+ * increment it (round up) only if the other is within 50%.
+ */
+static u8 cm_ack_timeout(u8 ca_ack_delay, u8 packet_life_time)
+{
+        int ack_timeout = packet_life_time + 1;
+
+        if (ack_timeout >= ca_ack_delay)
+                ack_timeout += (ca_ack_delay >= (ack_timeout - 1));
+        else
+                ack_timeout = ca_ack_delay +
+                              (ack_timeout >= (ca_ack_delay - 1));
+
+        return min(31, ack_timeout);
+}
+
 static void cm_cleanup_timewait(struct cm_timewait_info *timewait_info)
 {
         if (timewait_info->inserted_remote_id) {
@@ -686,7 +707,7 @@ static void cm_enter_timewait(struct cm_id_private *cm_id_priv)
          * timewait before notifying the user that we've exited timewait.
          */
         cm_id_priv->id.state = IB_CM_TIMEWAIT;
-        wait_time = cm_convert_to_ms(cm_id_priv->av.packet_life_time + 1);
+        wait_time = cm_convert_to_ms(cm_id_priv->av.timeout);
         queue_delayed_work(cm.wq, &cm_id_priv->timewait_info->work.work,
                            msecs_to_jiffies(wait_time));
         cm_id_priv->timewait_info = NULL;
@@ -908,7 +929,8 @@ static void cm_format_req(struct cm_req_msg *req_msg,
         cm_req_set_primary_sl(req_msg, param->primary_path->sl);
         cm_req_set_primary_subnet_local(req_msg, 1); /* local only... */
         cm_req_set_primary_local_ack_timeout(req_msg,
-                min(31, param->primary_path->packet_life_time + 1));
+                cm_ack_timeout(cm_id_priv->av.port->cm_dev->ack_delay,
+                               param->primary_path->packet_life_time));
 
         if (param->alternate_path) {
                 req_msg->alt_local_lid = param->alternate_path->slid;
@@ -923,7 +945,8 @@ static void cm_format_req(struct cm_req_msg *req_msg,
                 cm_req_set_alt_sl(req_msg, param->alternate_path->sl);
                 cm_req_set_alt_subnet_local(req_msg, 1); /* local only... */
                 cm_req_set_alt_local_ack_timeout(req_msg,
-                        min(31, param->alternate_path->packet_life_time + 1));
+                        cm_ack_timeout(cm_id_priv->av.port->cm_dev->ack_delay,
+                                       param->alternate_path->packet_life_time));
         }
 
         if (param->private_data && param->private_data_len)
@@ -1433,7 +1456,8 @@ static void cm_format_rep(struct cm_rep_msg *rep_msg,
         cm_rep_set_starting_psn(rep_msg, cpu_to_be32(param->starting_psn));
         rep_msg->resp_resources = param->responder_resources;
         rep_msg->initiator_depth = param->initiator_depth;
-        cm_rep_set_target_ack_delay(rep_msg, param->target_ack_delay);
+        cm_rep_set_target_ack_delay(rep_msg,
+                                    cm_id_priv->av.port->cm_dev->ack_delay);
         cm_rep_set_failover(rep_msg, param->failover_accepted);
         cm_rep_set_flow_ctrl(rep_msg, param->flow_control);
         cm_rep_set_rnr_retry_count(rep_msg, param->rnr_retry_count);
@@ -1680,6 +1704,13 @@ static int cm_rep_handler(struct cm_work *work)
         cm_id_priv->responder_resources = rep_msg->initiator_depth;
         cm_id_priv->sq_psn = cm_rep_get_starting_psn(rep_msg);
         cm_id_priv->rnr_retry_count = cm_rep_get_rnr_retry_count(rep_msg);
+        cm_id_priv->target_ack_delay = cm_rep_get_target_ack_delay(rep_msg);
+        cm_id_priv->av.timeout =
+                        cm_ack_timeout(cm_id_priv->target_ack_delay,
+                                       cm_id_priv->av.timeout - 1);
+        cm_id_priv->alt_av.timeout =
+                        cm_ack_timeout(cm_id_priv->target_ack_delay,
+                                       cm_id_priv->alt_av.timeout - 1);
 
         /* todo: handle peer_to_peer */
 
@@ -2291,7 +2322,7 @@ static int cm_mra_handler(struct cm_work *work)
         work->cm_event.param.mra_rcvd.service_timeout =
                                         cm_mra_get_service_timeout(mra_msg);
         timeout = cm_convert_to_ms(cm_mra_get_service_timeout(mra_msg)) +
-                  cm_convert_to_ms(cm_id_priv->av.packet_life_time);
+                  cm_convert_to_ms(cm_id_priv->av.timeout);
 
         spin_lock_irq(&cm_id_priv->lock);
         switch (cm_id_priv->id.state) {
@@ -2363,7 +2394,8 @@ static void cm_format_lap(struct cm_lap_msg *lap_msg,
         cm_lap_set_sl(lap_msg, alternate_path->sl);
         cm_lap_set_subnet_local(lap_msg, 1); /* local only... */
         cm_lap_set_local_ack_timeout(lap_msg,
-                min(31, alternate_path->packet_life_time + 1));
+                cm_ack_timeout(cm_id_priv->av.port->cm_dev->ack_delay,
+                               alternate_path->packet_life_time));
 
         if (private_data && private_data_len)
                 memcpy(lap_msg->private_data, private_data, private_data_len);
@@ -2394,6 +2426,9 @@ int ib_send_cm_lap(struct ib_cm_id *cm_id,
         ret = cm_init_av_by_path(alternate_path, &cm_id_priv->alt_av);
         if (ret)
                 goto out;
+        cm_id_priv->alt_av.timeout =
+                        cm_ack_timeout(cm_id_priv->target_ack_delay,
+                                       cm_id_priv->alt_av.timeout - 1);
 
         ret = cm_alloc_msg(cm_id_priv, &msg);
         if (ret)
@@ -3248,8 +3283,7 @@ static int cm_init_qp_rtr_attr(struct cm_id_private *cm_id_priv,
                         *qp_attr_mask |= IB_QP_ALT_PATH;
                         qp_attr->alt_port_num = cm_id_priv->alt_av.port->port_num;
                         qp_attr->alt_pkey_index = cm_id_priv->alt_av.pkey_index;
-                        qp_attr->alt_timeout =
-                                        cm_id_priv->alt_av.packet_life_time + 1;
+                        qp_attr->alt_timeout = cm_id_priv->alt_av.timeout;
                         qp_attr->alt_ah_attr = cm_id_priv->alt_av.ah_attr;
                 }
                 ret = 0;
@@ -3287,8 +3321,7 @@ static int cm_init_qp_rts_attr(struct cm_id_private *cm_id_priv,
                                 *qp_attr_mask |= IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
                                                  IB_QP_RNR_RETRY |
                                                  IB_QP_MAX_QP_RD_ATOMIC;
-                                qp_attr->timeout =
-                                        cm_id_priv->av.packet_life_time + 1;
+                                qp_attr->timeout = cm_id_priv->av.timeout;
                                 qp_attr->retry_cnt = cm_id_priv->retry_count;
                                 qp_attr->rnr_retry = cm_id_priv->rnr_retry_count;
                                 qp_attr->max_rd_atomic =
@@ -3302,8 +3335,7 @@ static int cm_init_qp_rts_attr(struct cm_id_private *cm_id_priv,
                         *qp_attr_mask = IB_QP_ALT_PATH | IB_QP_PATH_MIG_STATE;
                         qp_attr->alt_port_num = cm_id_priv->alt_av.port->port_num;
                         qp_attr->alt_pkey_index = cm_id_priv->alt_av.pkey_index;
-                        qp_attr->alt_timeout =
-                                cm_id_priv->alt_av.packet_life_time + 1;
+                        qp_attr->alt_timeout = cm_id_priv->alt_av.timeout;
                         qp_attr->alt_ah_attr = cm_id_priv->alt_av.ah_attr;
                         qp_attr->path_mig_state = IB_MIG_REARM;
                 }
@@ -3343,6 +3375,16 @@ int ib_cm_init_qp_attr(struct ib_cm_id *cm_id,
 }
 EXPORT_SYMBOL(ib_cm_init_qp_attr);
 
+void cm_get_ack_delay(struct cm_device *cm_dev)
+{
+        struct ib_device_attr attr;
+
+        if (ib_query_device(cm_dev->device, &attr))
+                cm_dev->ack_delay = 0; /* acks will rely on packet life time */
+        else
+                cm_dev->ack_delay = attr.local_ca_ack_delay;
+}
+
 static void cm_add_one(struct ib_device *device)
 {
         struct cm_device *cm_dev;
@@ -3367,6 +3409,7 @@ static void cm_add_one(struct ib_device *device)
                 return;
 
         cm_dev->device = device;
+        cm_get_ack_delay(cm_dev);
 
         set_bit(IB_MGMT_METHOD_SEND, reg_req.method_mask);
         for (i = 1; i <= device->phys_port_cnt; i++) {
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 32a0e66d2a23..23af7a032a03 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -2326,7 +2326,6 @@ static int cma_accept_ib(struct rdma_id_private *id_priv,
         rep.private_data_len = conn_param->private_data_len;
         rep.responder_resources = conn_param->responder_resources;
         rep.initiator_depth = conn_param->initiator_depth;
-        rep.target_ack_delay = CMA_CM_RESPONSE_TIMEOUT;
         rep.failover_accepted = 0;
         rep.flow_control = conn_param->flow_control;
         rep.rnr_retry_count = conn_param->rnr_retry_count;
diff --git a/drivers/infiniband/core/ucm.c b/drivers/infiniband/core/ucm.c
index 2586a3ee8eba..424983f5b1ee 100644
--- a/drivers/infiniband/core/ucm.c
+++ b/drivers/infiniband/core/ucm.c
@@ -823,7 +823,6 @@ static ssize_t ib_ucm_send_rep(struct ib_ucm_file *file,
         param.private_data_len    = cmd.len;
         param.responder_resources = cmd.responder_resources;
         param.initiator_depth     = cmd.initiator_depth;
-        param.target_ack_delay    = cmd.target_ack_delay;
         param.failover_accepted   = cmd.failover_accepted;
         param.flow_control        = cmd.flow_control;
         param.rnr_retry_count     = cmd.rnr_retry_count;
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
index 6764d216c887..08b4676a3820 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -281,7 +281,6 @@ static int ipoib_cm_send_rep(struct net_device *dev, struct ib_cm_id *cm_id,
         rep.private_data_len = sizeof data;
         rep.flow_control = 0;
         rep.rnr_retry_count = req->rnr_retry_count;
-        rep.target_ack_delay = 20; /* FIXME */
         rep.srq = 1;
         rep.qp_num = qp->qp_num;
         rep.starting_psn = psn;
diff --git a/include/rdma/ib_cm.h b/include/rdma/ib_cm.h
index 5c070176d9ab..12243e80c706 100644
--- a/include/rdma/ib_cm.h
+++ b/include/rdma/ib_cm.h
@@ -385,7 +385,6 @@ struct ib_cm_rep_param {
         u8              private_data_len;
         u8              responder_resources;
         u8              initiator_depth;
-        u8              target_ack_delay;
         u8              failover_accepted;
         u8              flow_control;
         u8              rnr_retry_count;