mlx4_core: Use MOD_STAT_CFG command to get minimal page size
There was a bug in some versions of the mlx4 driver in
mlx4_alloc_fmr(), which hardcoded the minimum acceptable page_shift to
be 12. However, new ConnectX firmware can support a minimum
page_shift of 9 (log_pg_sz of 9 returned by QUERY_DEV_LIM) -- so with
old drivers, ib_fmr_alloc() would fail for ULPs using the device
minimum when creating FMRs.
To preserve firmware compatibility with released mlx4 drivers, the
firmware will continue to return 12 as before for log_page_sz in
QUERY_DEV_CAP for these drivers. However, to enable new drivers to
take advantage of the available smaller page size, the mlx4 driver now
first sets the log_pg_sz to the device minimum by setting a
log_page_sz value to 0 via the MOD_STAT_CFG command and then reading
the real minimum via QUERY_DEV_CAP.
Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Vladimir Sokolovsky <vlad@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/net/mlx4/main.c b/drivers/net/mlx4/main.c
index a6aa49f..d373601 100644
--- a/drivers/net/mlx4/main.c
+++ b/drivers/net/mlx4/main.c
@@ -485,6 +485,7 @@
struct mlx4_priv *priv = mlx4_priv(dev);
struct mlx4_adapter adapter;
struct mlx4_dev_cap dev_cap;
+ struct mlx4_mod_stat_cfg mlx4_cfg;
struct mlx4_profile profile;
struct mlx4_init_hca_param init_hca;
u64 icm_size;
@@ -502,6 +503,12 @@
return err;
}
+ mlx4_cfg.log_pg_sz_m = 1;
+ mlx4_cfg.log_pg_sz = 0;
+ err = mlx4_MOD_STAT_CFG(dev, &mlx4_cfg);
+ if (err)
+ mlx4_warn(dev, "Failed to override log_pg_sz parameter\n");
+
err = mlx4_dev_cap(dev, &dev_cap);
if (err) {
mlx4_err(dev, "QUERY_DEV_CAP command failed, aborting.\n");