IB/mthca: Implement query_ah method

Implement query_ah (except for AVs which are in HCA memory).  This is
needed to implement RMPP duplicate session detection on sending side
(extraction of DGID/DLID and GRH flag from address handle).

Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

3 files changed, 33 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_av.c b/drivers/infiniband/hw/mthca/mthca_av.c
index 198f1267e984..f023d3936518 100644
--- a/drivers/infiniband/hw/mthca/mthca_av.c
+++ b/drivers/infiniband/hw/mthca/mthca_av.c
@@ -193,6 +193,37 @@ int mthca_read_ah(struct mthca_dev *dev, struct mthca_ah *ah,
         return 0;
 }
 
+int mthca_ah_query(struct ib_ah *ibah, struct ib_ah_attr *attr)
+{
+        struct mthca_ah *ah   = to_mah(ibah);
+        struct mthca_dev *dev = to_mdev(ibah->device);
+
+        /* Only implement for MAD and memfree ah for now. */
+        if (ah->type == MTHCA_AH_ON_HCA)
+                return -ENOSYS;
+
+        memset(attr, 0, sizeof *attr);
+        attr->dlid          = be16_to_cpu(ah->av->dlid);
+        attr->sl            = be32_to_cpu(ah->av->sl_tclass_flowlabel) >> 28;
+        attr->static_rate   = ah->av->msg_sr & 0x7;
+        attr->src_path_bits = ah->av->g_slid & 0x7F;
+        attr->port_num      = be32_to_cpu(ah->av->port_pd) >> 24;
+        attr->ah_flags      = mthca_ah_grh_present(ah) ? IB_AH_GRH : 0;
+
+        if (attr->ah_flags) {
+                attr->grh.traffic_class =
+                        be32_to_cpu(ah->av->sl_tclass_flowlabel) >> 20;
+                attr->grh.flow_label =
+                        be32_to_cpu(ah->av->sl_tclass_flowlabel) & 0xfffff;
+                attr->grh.hop_limit  = ah->av->hop_limit;
+                attr->grh.sgid_index = ah->av->gid_index &
+                                       (dev->limits.gid_table_len - 1);
+                memcpy(attr->grh.dgid.raw, ah->av->dgid, 16);
+        }
+
+        return 0;
+}
+
 int __devinit mthca_init_av_table(struct mthca_dev *dev)
 {
         int err;
diff --git a/drivers/infiniband/hw/mthca/mthca_dev.h b/drivers/infiniband/hw/mthca/mthca_dev.h
index b2aea80a683f..ea48c897c7ce 100644
--- a/drivers/infiniband/hw/mthca/mthca_dev.h
+++ b/drivers/infiniband/hw/mthca/mthca_dev.h
@@ -539,6 +539,7 @@ int mthca_create_ah(struct mthca_dev *dev,
 int mthca_destroy_ah(struct mthca_dev *dev, struct mthca_ah *ah);
 int mthca_read_ah(struct mthca_dev *dev, struct mthca_ah *ah,
                   struct ib_ud_header *header);
+int mthca_ah_query(struct ib_ah *ibah, struct ib_ah_attr *attr);
 int mthca_ah_grh_present(struct mthca_ah *ah);
 
 int mthca_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid);
diff --git a/drivers/infiniband/hw/mthca/mthca_provider.c b/drivers/infiniband/hw/mthca/mthca_provider.c
index 084bea592df5..2c250bc11c33 100644
--- a/drivers/infiniband/hw/mthca/mthca_provider.c
+++ b/drivers/infiniband/hw/mthca/mthca_provider.c
@@ -1289,6 +1289,7 @@ int mthca_register_device(struct mthca_dev *dev)
         dev->ib_dev.alloc_pd             = mthca_alloc_pd;
         dev->ib_dev.dealloc_pd           = mthca_dealloc_pd;
         dev->ib_dev.create_ah            = mthca_ah_create;
+        dev->ib_dev.query_ah             = mthca_ah_query;
         dev->ib_dev.destroy_ah           = mthca_ah_destroy;
 
         if (dev->mthca_flags & MTHCA_FLAG_SRQ) {