IB/mthca: Add modify_device method to set node description

Add a modify_device method to mthca, which implements setting the node
description.  This makes the writable "node_desc" sysfs attribute work
for Mellanox HCAs.

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 16 insertions, 1 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_mad.c b/drivers/infiniband/hw/mthca/mthca_mad.c
index 1229c604c6e0..4ace6a392f41 100644
--- a/drivers/infiniband/hw/mthca/mthca_mad.c
+++ b/drivers/infiniband/hw/mthca/mthca_mad.c
@@ -109,6 +109,19 @@ static void smp_snoop(struct ib_device *ibdev,
         }
 }
 
+static void node_desc_override(struct ib_device *dev,
+                               struct ib_mad *mad)
+{
+        if ((mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED ||
+             mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) &&
+            mad->mad_hdr.method == IB_MGMT_METHOD_GET_RESP &&
+            mad->mad_hdr.attr_id == IB_SMP_ATTR_NODE_DESC) {
+                mutex_lock(&to_mdev(dev)->cap_mask_mutex);
+                memcpy(((struct ib_smp *) mad)->data, dev->node_desc, 64);
+                mutex_unlock(&to_mdev(dev)->cap_mask_mutex);
+        }
+}
+
 static void forward_trap(struct mthca_dev *dev,
                          u8 port_num,
                          struct ib_mad *mad)
@@ -207,8 +220,10 @@ int mthca_process_mad(struct ib_device *ibdev,
                 return IB_MAD_RESULT_FAILURE;
         }
 
-        if (!out_mad->mad_hdr.status)
+        if (!out_mad->mad_hdr.status) {
                 smp_snoop(ibdev, port_num, in_mad);
+                node_desc_override(ibdev, out_mad);
+        }
 
         /* set return bit in status of directed route responses */
         if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)