mlx4_core: Get the maximum message size from reported device capabilities

Get the maximum message size from the device capabilities returned
from the QUERY_DEV_CAP firmware command, rather than hard-coding 2 GB.

Signed-off-by: Dotan Barak <dotanb@dev.mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@dev.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 c3da2a2..a4f2e04 100644
--- a/drivers/net/mlx4/main.c
+++ b/drivers/net/mlx4/main.c
@@ -154,6 +154,7 @@
 	dev->caps.reserved_uars	     = dev_cap->reserved_uars;
 	dev->caps.reserved_pds	     = dev_cap->reserved_pds;
 	dev->caps.mtt_entry_sz	     = MLX4_MTT_ENTRY_PER_SEG * dev_cap->mtt_entry_sz;
+	dev->caps.max_msg_sz         = dev_cap->max_msg_sz;
 	dev->caps.page_size_cap	     = ~(u32) (dev_cap->min_page_sz - 1);
 	dev->caps.flags		     = dev_cap->flags;
 	dev->caps.stat_rate_support  = dev_cap->stat_rate_support;