IB/mlx5: Don't expose debugfs entries for RRoCE general parameters if…

… not supported

[ Upstream commit 43fdbd1 ]

debugfs entries for RRoCE general CC parameters must be exposed only when
they are supported, otherwise when accessing them there may be a syndrome
error in kernel log, for example:

$ cat /sys/kernel/debug/mlx5/0000:08:00.1/cc_params/rtt_resp_dscp
cat: '/sys/kernel/debug/mlx5/0000:08:00.1/cc_params/rtt_resp_dscp': Invalid argument
$ dmesg
 mlx5_core 0000:08:00.1: mlx5_cmd_out_err:805:(pid 1253): QUERY_CONG_PARAMS(0x824) op_mod(0x0) failed, status bad parameter(0x3), syndrome (0x325a82), err(-22)

Fixes: 66fb1d5 ("IB/mlx5: Extend debug control for CC parameters")
Reviewed-by: Edward Srouji <edwards@nvidia.com>
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Link: https://lore.kernel.org/r/e7ade70bad52b7468bdb1de4d41d5fad70c8b71c.1706433934.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/infiniband/hw/mlx5/cong.c

@@ -458,6 +458,12 @@ void mlx5_ib_init_cong_debugfs(struct mlx5_ib_dev *dev, u32 port_num)
 	dbg_cc_params->root = debugfs_create_dir("cc_params", mlx5_debugfs_get_dev_root(mdev));
 
 	for (i = 0; i < MLX5_IB_DBG_CC_MAX; i++) {
+		if ((i == MLX5_IB_DBG_CC_GENERAL_RTT_RESP_DSCP_VALID ||
+		     i == MLX5_IB_DBG_CC_GENERAL_RTT_RESP_DSCP))
+			if (!MLX5_CAP_GEN(mdev, roce) ||
+			    !MLX5_CAP_ROCE(mdev, roce_cc_general))
+				continue;
+
 		dbg_cc_params->params[i].offset = i;
 		dbg_cc_params->params[i].dev = dev;
 		dbg_cc_params->params[i].port_num = port_num;

include/linux/mlx5/mlx5_ifc.h

@@ -1102,7 +1102,7 @@ struct mlx5_ifc_roce_cap_bits {
 	u8         sw_r_roce_src_udp_port[0x1];
 	u8         fl_rc_qp_when_roce_disabled[0x1];
 	u8         fl_rc_qp_when_roce_enabled[0x1];
-	u8         reserved_at_7[0x1];
+	u8         roce_cc_general[0x1];
 	u8	   qp_ooo_transmit_default[0x1];
 	u8         reserved_at_9[0x15];
 	u8	   qp_ts_format[0x2];