[PATCH 4.14 29/69] net/mlx5e: Add a lock on tir list

[Greg Kroah-Hartman]

From: Yuval Avnery <yuva...@mellanox.com>

[ Upstream commit 80a2a9026b24c6bd34b8d58256973e22270bedec ]

Refresh tirs is looping over a global list of tirs while netdevs are
adding and removing tirs from that list. That is why a lock is
required.

Fixes: 724b2aa15126 ("net/mlx5e: TIRs management refactoring")
Signed-off-by: Yuval Avnery <yuva...@mellanox.com>
Signed-off-by: Saeed Mahameed <sae...@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_common.c |    7 +++++++
 include/linux/mlx5/driver.h                         |    2 ++
 2 files changed, 9 insertions(+)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_common.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_common.c
@@ -45,7 +45,9 @@ int mlx5e_create_tir(struct mlx5_core_de
        if (err)
                return err;
 
+       mutex_lock(&mdev->mlx5e_res.td.list_lock);
        list_add(&tir->list, &mdev->mlx5e_res.td.tirs_list);
+       mutex_unlock(&mdev->mlx5e_res.td.list_lock);
 
        return 0;
 }
@@ -53,8 +55,10 @@ int mlx5e_create_tir(struct mlx5_core_de
 void mlx5e_destroy_tir(struct mlx5_core_dev *mdev,
                       struct mlx5e_tir *tir)
 {
+       mutex_lock(&mdev->mlx5e_res.td.list_lock);
        mlx5_core_destroy_tir(mdev, tir->tirn);
        list_del(&tir->list);
+       mutex_unlock(&mdev->mlx5e_res.td.list_lock);
 }
 
 static int mlx5e_create_mkey(struct mlx5_core_dev *mdev, u32 pdn,
@@ -114,6 +118,7 @@ int mlx5e_create_mdev_resources(struct m
        }
 
        INIT_LIST_HEAD(&mdev->mlx5e_res.td.tirs_list);
+       mutex_init(&mdev->mlx5e_res.td.list_lock);
 
        return 0;
 
@@ -158,6 +163,7 @@ int mlx5e_refresh_tirs(struct mlx5e_priv
 
        MLX5_SET(modify_tir_in, in, bitmask.self_lb_en, 1);
 
+       mutex_lock(&mdev->mlx5e_res.td.list_lock);
        list_for_each_entry(tir, &mdev->mlx5e_res.td.tirs_list, list) {
                tirn = tir->tirn;
                err = mlx5_core_modify_tir(mdev, tirn, in, inlen);
@@ -169,6 +175,7 @@ out:
        kvfree(in);
        if (err)
                netdev_err(priv->netdev, "refresh tir(0x%x) failed, %d\n", 
tirn, err);
+       mutex_unlock(&mdev->mlx5e_res.td.list_lock);
 
        return err;
 }
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -743,6 +743,8 @@ struct mlx5_pagefault {
 };
 
 struct mlx5_td {
+       /* protects tirs list changes while tirs refresh */
+       struct mutex     list_lock;
        struct list_head tirs_list;
        u32              tdn;
 };