[focal:linux-azure, groovy:linux-azure][PATCH 1/1] RDMA/mlx4: Read pkey table length instead of hardcoded value

[Marcelo Henrique Cerri]

From: Mark Bloch <markb at mellanox.com>

BugLink: https://bugs.launchpad.net/bugs/1896760

If the pkey_table is not available (which is the case when RoCE is not
supported), the cited commit caused a regression where mlx4_devices
without RoCE are not created.

Fix this by returning a pkey table length of zero in procedure
eth_link_query_port() if the pkey-table length reported by the device is
zero.

Link: https://lore.kernel.org/r/20200824110229.1094376-1-leon@kernel.org
Cc: <stable at vger.kernel.org>
Fixes: 1901b91f9982 ("IB/core: Fix potential NULL pointer dereference in pkey cache")
Fixes: fa417f7b520e ("IB/mlx4: Add support for IBoE")
Signed-off-by: Mark Bloch <markb at mellanox.com>
Reviewed-by: Maor Gottlieb <maorg at nvidia.com>
Signed-off-by: Leon Romanovsky <leonro at nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
(cherry picked from commit ec78b3bd66bc9a015505df0ef0eb153d9e64b03b)
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri at canonical.com>
---
 drivers/infiniband/hw/mlx4/main.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index c46826d34ac8..4860d484f733 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -781,7 +781,8 @@ static int eth_link_query_port(struct ib_device *ibdev, u8 port,
 	props->ip_gids = true;
 	props->gid_tbl_len	= mdev->dev->caps.gid_table_len[port];
 	props->max_msg_sz	= mdev->dev->caps.max_msg_sz;
-	props->pkey_tbl_len	= 1;
+	if (mdev->dev->caps.pkey_table_len[port])
+		props->pkey_tbl_len = 1;
 	props->max_mtu		= IB_MTU_4096;
 	props->max_vl_num	= 2;
 	props->state		= IB_PORT_DOWN;
-- 
2.25.1