[PATCH 5.4 028/104] net/mlx5: DR, use non preemptible call to get the current cpu number

From: Greg Kroah-Hartman
Date: Tue Jan 28 2020 - 09:02:14 EST


From: Erez Shitrit <erezsh@xxxxxxxxxxxx>

commit c0702a4bd41829f05638ec2dab70f6bb8d8010ce upstream.

Use raw_smp_processor_id instead of smp_processor_id() otherwise we will
get the following trace in debug-kernel:
BUG: using smp_processor_id() in preemptible [00000000] code: devlink
caller is dr_create_cq.constprop.2+0x31d/0x970 [mlx5_core]
Call Trace:
dump_stack+0x9a/0xf0
debug_smp_processor_id+0x1f3/0x200
dr_create_cq.constprop.2+0x31d/0x970
genl_family_rcv_msg+0x5fd/0x1170
genl_rcv_msg+0xb8/0x160
netlink_rcv_skb+0x11e/0x340

Fixes: 297cccebdc5a ("net/mlx5: DR, Expose an internal API to issue RDMA operations")
Signed-off-by: Erez Shitrit <erezsh@xxxxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/mellanox/mlx5/core/steering/dr_send.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_send.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_send.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/* Copyright (c) 2019 Mellanox Technologies. */

+#include <linux/smp.h>
#include "dr_types.h"

#define QUEUE_SIZE 128
@@ -729,7 +730,7 @@ static struct mlx5dr_cq *dr_create_cq(st
if (!in)
goto err_cqwq;

- vector = smp_processor_id() % mlx5_comp_vectors_count(mdev);
+ vector = raw_smp_processor_id() % mlx5_comp_vectors_count(mdev);
err = mlx5_vector2eqn(mdev, vector, &eqn, &irqn);
if (err) {
kvfree(in);