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>

3 files changed, 6 insertions, 1 deletions

diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index 7b445df6a667..e152837b75a5 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -163,7 +163,7 @@ static int mlx4_ib_query_device(struct ib_device *ibdev,
         props->max_mcast_qp_attach = dev->dev->caps.num_qp_per_mgm;
         props->max_total_mcast_qp_attach = props->max_mcast_qp_attach *
                                            props->max_mcast_grp;
-        props->max_map_per_fmr = (1 << (32 - ilog2(dev->dev->caps.num_mpts))) - 1;
+        props->max_map_per_fmr = dev->dev->caps.max_fmr_maps;
 
 out:
         kfree(in_mad);
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;
 
diff --git a/drivers/net/ethernet/mellanox/mlx4/mr.c b/drivers/net/ethernet/mellanox/mlx4/mr.c
index 25a80d71fb2a..5b7c06e0cd05 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mr.c
+++ b/drivers/net/ethernet/mellanox/mlx4/mr.c
@@ -816,6 +816,9 @@ int mlx4_fmr_alloc(struct mlx4_dev *dev, u32 pd, u32 access, int max_pages,
         u64 mtt_offset;
         int err = -ENOMEM;
 
+        if (max_maps > dev->caps.max_fmr_maps)
+                return -EINVAL;
+
         if (page_shift < (ffs(dev->caps.page_size_cap) - 1) || page_shift >= 32)
                 return -EINVAL;