[PATCH] IB: Add automatic retries to MAD layer

Add automatic retries to MAD layer.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Hal Rosenstock <halr@voltaire.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

5 files changed, 31 insertions, 2 deletions

diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index 430a6ee8987..04f88d33738 100644
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -954,7 +954,7 @@ int ib_post_send_mad(struct ib_mad_agent *mad_agent,
                 /* Timeout will be updated after send completes */
                 mad_send_wr->timeout = msecs_to_jiffies(send_wr->wr.
                                                         ud.timeout_ms);
-                mad_send_wr->retry = 0;
+                mad_send_wr->retries = mad_send_wr->send_wr.wr.ud.retries;
                 /* One reference for each work request to QP + response */
                 mad_send_wr->refcount = 1 + (mad_send_wr->timeout > 0);
                 mad_send_wr->status = IB_WC_SUCCESS;
@@ -2174,6 +2174,27 @@ local_send_completion:
         spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
 }
 
+static int retry_send(struct ib_mad_send_wr_private *mad_send_wr)
+{
+        int ret;
+
+        if (!mad_send_wr->retries--)
+                return -ETIMEDOUT;
+
+        mad_send_wr->timeout = msecs_to_jiffies(mad_send_wr->send_wr.
+                                                wr.ud.timeout_ms);
+
+        ret = ib_send_mad(mad_send_wr);
+
+        if (!ret) {
+                mad_send_wr->refcount++;
+                list_del(&mad_send_wr->agent_list);
+                list_add_tail(&mad_send_wr->agent_list,
+                              &mad_send_wr->mad_agent_priv->send_list);
+        }
+        return ret;
+}
+
 static void timeout_sends(void *data)
 {
         struct ib_mad_agent_private *mad_agent_priv;
@@ -2202,6 +2223,9 @@ static void timeout_sends(void *data)
                         break;
                 }
 
+                if (!retry_send(mad_send_wr))
+                        continue;
+
                 list_del(&mad_send_wr->agent_list);
                 spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
 
diff --git a/drivers/infiniband/core/mad_priv.h b/drivers/infiniband/core/mad_priv.h
index 6fcab0009bb..8a61dd921d2 100644
--- a/drivers/infiniband/core/mad_priv.h
+++ b/drivers/infiniband/core/mad_priv.h
@@ -123,6 +123,7 @@ struct ib_mad_send_wr_private {
         u64 wr_id;                      /* client WR ID */
         u64 tid;
         unsigned long timeout;
+        int retries;
         int retry;
         int refcount;
         enum ib_wc_status status;
@@ -136,6 +137,7 @@ struct ib_mad_local_private {
         struct ib_sge sg_list[IB_MAD_SEND_REQ_MAX_SG];
         u64 wr_id;                      /* client WR ID */
         u64 tid;
+        int retries;
 };
 
 struct ib_mad_mgmt_method_table {
diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
index 649824e3325..9ef8fe0163d 100644
--- a/drivers/infiniband/core/sa_query.c
+++ b/drivers/infiniband/core/sa_query.c
@@ -462,7 +462,8 @@ static int send_mad(struct ib_sa_query *query, int timeout_ms)
                                  .mad_hdr     = &query->mad->mad_hdr,
                                  .remote_qpn  = 1,
                                  .remote_qkey = IB_QP1_QKEY,
-                                 .timeout_ms  = timeout_ms
+                                 .timeout_ms  = timeout_ms,
+                                 .retries     = 0
                          }
                  }
         };
diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index 9d912d6877f..088bb1f0f51 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -322,6 +322,7 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
         wr.wr.ud.remote_qpn  = be32_to_cpu(packet->mad.qpn);
         wr.wr.ud.remote_qkey = be32_to_cpu(packet->mad.qkey);
         wr.wr.ud.timeout_ms  = packet->mad.timeout_ms;
+        wr.wr.ud.retries     = 0;
 
         wr.wr_id            = (unsigned long) packet;
 
diff --git a/drivers/infiniband/include/ib_verbs.h b/drivers/infiniband/include/ib_verbs.h
index e5bd9a10c20..b6107c4b683 100644
--- a/drivers/infiniband/include/ib_verbs.h
+++ b/drivers/infiniband/include/ib_verbs.h
@@ -566,6 +566,7 @@ struct ib_send_wr {
                         u32     remote_qpn;
                         u32     remote_qkey;
                         int     timeout_ms; /* valid for MADs only */
+                        int     retries;    /* valid for MADs only */
                         u16     pkey_index; /* valid for GSI only */
                         u8      port_num;   /* valid for DR SMPs on switch only */
                 } ud;