mlx4_core: Write MTTs from CPU instead with of WRITE_MTT FW command

Write MTT entries directly to ICM from the driver (eliminating use of
WRITE_MTT command).  This reduces the number of FW commands needed to
register an MR by at least a factor of 2 and speeds up memory
registration significantly.  This code will also be used to implement
FMRs.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/infiniband/hw/mlx4/mr.c b/drivers/infiniband/hw/mlx4/mr.c
index 85ae906f1d12..734ec2bd15cd 100644
--- a/drivers/infiniband/hw/mlx4/mr.c
+++ b/drivers/infiniband/hw/mlx4/mr.c
@@ -96,11 +96,10 @@ int mlx4_ib_umem_write_mtt(struct mlx4_ib_dev *dev, struct mlx4_mtt *mtt,
                                 pages[i++] = sg_dma_address(&chunk->page_list[j]) +
                                         umem->page_size * k;
                                 /*
-                                 * Be friendly to WRITE_MTT firmware
-                                 * command, and pass it chunks of
-                                 * appropriate size.
+                                 * Be friendly to mlx4_write_mtt() and
+                                 * pass it chunks of appropriate size.
                                  */
-                                if (i == PAGE_SIZE / sizeof (u64) - 2) {
+                                if (i == PAGE_SIZE / sizeof (u64)) {
                                         err = mlx4_write_mtt(dev->dev, mtt, n,
                                                              i, pages);
                                         if (err)