IB/mad: Enhance SMI for switch support

Extend the SMI with switch (intermediate hop) support. Care has been
taken to ensure that the CA (and router) code paths are changed as
little as possible.

Signed-off-by: Suresh Shelvapille <suri@baymicrosystems.com>
Signed-off-by: Hal Rosenstock <halr@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 41 insertions, 9 deletions

diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index 85ccf13b8041..6b8faca02f8a 100644
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -675,10 +675,16 @@ static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
         struct ib_mad_port_private *port_priv;
         struct ib_mad_agent_private *recv_mad_agent = NULL;
         struct ib_device *device = mad_agent_priv->agent.device;
-        u8 port_num = mad_agent_priv->agent.port_num;
+        u8 port_num;
         struct ib_wc mad_wc;
         struct ib_send_wr *send_wr = &mad_send_wr->send_wr;
 
+        if (device->node_type == RDMA_NODE_IB_SWITCH &&
+            smp->mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
+                port_num = send_wr->wr.ud.port_num;
+        else
+                port_num = mad_agent_priv->agent.port_num;
+
         /*
          * Directed route handling starts if the initial LID routed part of
          * a request or the ending LID routed part of a response is empty.
@@ -1839,6 +1845,7 @@ static void ib_mad_recv_done_handler(struct ib_mad_port_private *port_priv,
         struct ib_mad_private *recv, *response;
         struct ib_mad_list_head *mad_list;
         struct ib_mad_agent_private *mad_agent;
+        int port_num;
 
         response = kmem_cache_alloc(ib_mad_cache, GFP_KERNEL);
         if (!response)
@@ -1872,25 +1879,50 @@ static void ib_mad_recv_done_handler(struct ib_mad_port_private *port_priv,
         if (!validate_mad(&recv->mad.mad, qp_info->qp->qp_num))
                 goto out;
 
+        if (port_priv->device->node_type == RDMA_NODE_IB_SWITCH)
+                port_num = wc->port_num;
+        else
+                port_num = port_priv->port_num;
+
         if (recv->mad.mad.mad_hdr.mgmt_class ==
             IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
+                enum smi_forward_action retsmi;
+
                 if (smi_handle_dr_smp_recv(&recv->mad.smp,
                                            port_priv->device->node_type,
-                                           port_priv->port_num,
+                                           port_num,
                                            port_priv->device->phys_port_cnt) ==
                                            IB_SMI_DISCARD)
                         goto out;
 
-                if (smi_check_forward_dr_smp(&recv->mad.smp) == IB_SMI_LOCAL)
+                retsmi = smi_check_forward_dr_smp(&recv->mad.smp);
+                if (retsmi == IB_SMI_LOCAL)
                         goto local;
 
-                if (smi_handle_dr_smp_send(&recv->mad.smp,
-                                           port_priv->device->node_type,
-                                           port_priv->port_num) == IB_SMI_DISCARD)
-                        goto out;
+                if (retsmi == IB_SMI_SEND) { /* don't forward */
+                        if (smi_handle_dr_smp_send(&recv->mad.smp,
+                                                   port_priv->device->node_type,
+                                                   port_num) == IB_SMI_DISCARD)
+                                goto out;
+
+                        if (smi_check_local_smp(&recv->mad.smp, port_priv->device) == IB_SMI_DISCARD)
+                                goto out;
+                } else if (port_priv->device->node_type == RDMA_NODE_IB_SWITCH) {
+                        /* forward case for switches */
+                        memcpy(response, recv, sizeof(*response));
+                        response->header.recv_wc.wc = &response->header.wc;
+                        response->header.recv_wc.recv_buf.mad = &response->mad.mad;
+                        response->header.recv_wc.recv_buf.grh = &response->grh;
+
+                        if (!agent_send_response(&response->mad.mad,
+                                                 &response->grh, wc,
+                                                 port_priv->device,
+                                                 smi_get_fwd_port(&recv->mad.smp),
+                                                 qp_info->qp->qp_num))
+                                response = NULL;
 
-                if (smi_check_local_smp(&recv->mad.smp, port_priv->device) == IB_SMI_DISCARD)
                         goto out;
+                }
         }
 
 local:
@@ -1919,7 +1951,7 @@ local:
                                 agent_send_response(&response->mad.mad,
                                                     &recv->grh, wc,
                                                     port_priv->device,
-                                                    port_priv->port_num,
+                                                    port_num,
                                                     qp_info->qp->qp_num);
                                 goto out;
                         }