1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/profile.c b/drivers/net/ethernet/mellanox/mlx4/profile.c
index 1129677daa62..06e5adeb76f7 100644
--- a/drivers/net/ethernet/mellanox/mlx4/profile.c
+++ b/drivers/net/ethernet/mellanox/mlx4/profile.c
@@ -83,12 +83,31 @@ u64 mlx4_make_profile(struct mlx4_dev *dev,
         u64 total_size = 0;
         struct mlx4_resource *profile;
         struct mlx4_resource tmp;
+        struct sysinfo si;
         int i, j;
 
         profile = kcalloc(MLX4_RES_NUM, sizeof(*profile), GFP_KERNEL);
         if (!profile)
                 return -ENOMEM;
 
+        /*
+         * We want to scale the number of MTTs with the size of the
+         * system memory, since it makes sense to register a lot of
+         * memory on a system with a lot of memory.  As a heuristic,
+         * make sure we have enough MTTs to cover twice the system
+         * memory (with PAGE_SIZE entries).
+         *
+         * This number has to be a power of two and fit into 32 bits
+         * due to device limitations, so cap this at 2^31 as well.
+         * That limits us to 8TB of memory registration per HCA with
+         * 4KB pages, which is probably OK for the next few months.
+         */
+        si_meminfo(&si);
+        request->num_mtt =
+                roundup_pow_of_two(max_t(unsigned, request->num_mtt,
+                                         min(1UL << 31,
+                                             si.totalram >> (log_mtts_per_seg - 1))));
+
         profile[MLX4_RES_QP].size     = dev_cap->qpc_entry_sz;
         profile[MLX4_RES_RDMARC].size = dev_cap->rdmarc_entry_sz;
         profile[MLX4_RES_ALTC].size   = dev_cap->altc_entry_sz;