[PATCH 3.16 199/305] IB/mlx4: Properly initialize GRH TClass and FlowLabel in AHs

[Ben Hutchings]

3.16.37-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>

commit 8c5122e45a10a9262f872b53f151a592e870f905 upstream.

When this code was reworked for IBoE support the order of assignments
for the sl_tclass_flowlabel got flipped around resulting in
TClass & FlowLabel being permanently set to 0 in the packet headers.

This breaks IB routers that rely on these headers, but only affects
kernel users - libmlx4 does this properly for user space.

Fixes: fa417f7b520e ("IB/mlx4: Add support for IBoE")
Signed-off-by: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/infiniband/hw/mlx4/ah.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/infiniband/hw/mlx4/ah.c
+++ b/drivers/infiniband/hw/mlx4/ah.c
@@ -46,6 +46,7 @@ static struct ib_ah *create_ib_ah(struct
 
 	ah->av.ib.port_pd = cpu_to_be32(to_mpd(pd)->pdn | (ah_attr->port_num << 24));
 	ah->av.ib.g_slid  = ah_attr->src_path_bits;
+	ah->av.ib.sl_tclass_flowlabel = cpu_to_be32(ah_attr->sl << 28);
 	if (ah_attr->ah_flags & IB_AH_GRH) {
 		ah->av.ib.g_slid   |= 0x80;
 		ah->av.ib.gid_index = ah_attr->grh.sgid_index;
@@ -63,7 +64,6 @@ static struct ib_ah *create_ib_ah(struct
 		       !(1 << ah->av.ib.stat_rate & dev->caps.stat_rate_support))
 			--ah->av.ib.stat_rate;
 	}
-	ah->av.ib.sl_tclass_flowlabel = cpu_to_be32(ah_attr->sl << 28);
 
 	return &ah->ibah;
 }