IPoIB: improve IPv4/IPv6 to IB mcast mapping functions

An IPoIB subnet on an IB fabric that spans multiple IB subnets can't
use link-local scope in multicast GIDs.  The existing routines that
map IP/IPv6 multicast addresses into IB link-level addresses hard-code
the scope to link-local, and they also leave the partition key field
uninitialised.  This patch adds a parameter (the link-level broadcast
address) to the mapping routines, allowing them to initialise both the
scope and the P_Key appropriately, and fixes up the call sites.

The next step will be to add a way to configure the scope for an IPoIB
interface.

Signed-off-by: Rolf Manderscheid <rvm@obsidianresearch.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 1 insertions, 7 deletions

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 312ec74f3d18..982836e69f55 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -2610,11 +2610,9 @@ static void cma_set_mgid(struct rdma_id_private *id_priv,
                 /* IPv6 address is an SA assigned MGID. */
                 memcpy(mgid, &sin6->sin6_addr, sizeof *mgid);
         } else {
-                ip_ib_mc_map(sin->sin_addr.s_addr, mc_map);
+                ip_ib_mc_map(sin->sin_addr.s_addr, dev_addr->broadcast, mc_map);
                 if (id_priv->id.ps == RDMA_PS_UDP)
                         mc_map[7] = 0x01;       /* Use RDMA CM signature */
-                mc_map[8] = ib_addr_get_pkey(dev_addr) >> 8;
-                mc_map[9] = (unsigned char) ib_addr_get_pkey(dev_addr);
                 *mgid = *(union ib_gid *) (mc_map + 4);
         }
 }
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 858ada17f980..2628339e3a99 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -788,10 +788,6 @@ void ipoib_mcast_restart_task(struct work_struct *work)
 
                 memcpy(mgid.raw, mclist->dmi_addr + 4, sizeof mgid);
 
-                /* Add in the P_Key */
-                mgid.raw[4] = (priv->pkey >> 8) & 0xff;
-                mgid.raw[5] = priv->pkey & 0xff;
-
                 mcast = __ipoib_mcast_find(dev, &mgid);
                 if (!mcast || test_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags)) {
                         struct ipoib_mcast *nmcast;