mlx4: Enforce device max FMR maps in FMR alloc

ConnectX devices have a limit on the number of mappings that can be
done on an FMR before having to call sync_tpt.  The current
mlx4_ib driver reports the limit correctly in max_map_per_fmr in
.query_device(), but mlx4_core doesn't check it when actually
allocating FMRs.

Add a max_fmr_maps field to struct mlx4_caps and enforce this maximum
value on FMR allocations.

Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index 678558b502fc..3e593ae56e00 100644
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -1131,6 +1131,8 @@ static int mlx4_init_hca(struct mlx4_dev *dev)
                         goto err_stop_fw;
                 }
 
+                dev->caps.max_fmr_maps = (1 << (32 - ilog2(dev->caps.num_mpts))) - 1;
+
                 init_hca.log_uar_sz = ilog2(dev->caps.num_uars);
                 init_hca.uar_page_sz = PAGE_SHIFT - 12;