net/mlx5: E-Switch, Change mode lock from mutex to rw semaphore

stable inclusion
form stable-v5.10.82
commit 68748ea4d1225da644fa91263e4e019f4c72ddb7
bugzilla: 185877 https://gitee.com/openeuler/kernel/issues/I4QU6V

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=68748ea4d1225da644fa91263e4e019f4c72ddb7

--------------------------------

[ Upstream commit c55479d0 ]

E-Switch mode change routine will take the write lock to prevent any
consumer to access the E-Switch resources while E-Switch is going
through a mode change.

In the next patch
E-Switch consumers (e.g vport representors) will take read_lock prior to
accessing E-Switch resources to prevent E-Switch mode changing in the
middle of the operation.
Signed-off-by: NRoi Dayan <roid@nvidia.com>
Reviewed-by: NParav Pandit <parav@nvidia.com>
Signed-off-by: NSaeed Mahameed <saeedm@nvidia.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/net/ethernet/mellanox/mlx5/core/eswitch.c

@@ -1663,7 +1663,7 @@ int mlx5_eswitch_enable(struct mlx5_eswitch *esw, int num_vfs)
 	if (!ESW_ALLOWED(esw))
 		return 0;
 
-	mutex_lock(&esw->mode_lock);
+	down_write(&esw->mode_lock);
 	if (esw->mode == MLX5_ESWITCH_NONE) {
 		ret = mlx5_eswitch_enable_locked(esw, MLX5_ESWITCH_LEGACY, num_vfs);
 	} else {
@@ -1675,7 +1675,7 @@ int mlx5_eswitch_enable(struct mlx5_eswitch *esw, int num_vfs)
 		if (!ret)
 			esw->esw_funcs.num_vfs = num_vfs;
 	}
-	mutex_unlock(&esw->mode_lock);
+	up_write(&esw->mode_lock);
 	return ret;
 }
 
@@ -1719,10 +1719,10 @@ void mlx5_eswitch_disable(struct mlx5_eswitch *esw, bool clear_vf)
 	if (!ESW_ALLOWED(esw))
 		return;
 
-	mutex_lock(&esw->mode_lock);
+	down_write(&esw->mode_lock);
 	mlx5_eswitch_disable_locked(esw, clear_vf);
 	esw->esw_funcs.num_vfs = 0;
-	mutex_unlock(&esw->mode_lock);
+	up_write(&esw->mode_lock);
 }
 
 int mlx5_eswitch_init(struct mlx5_core_dev *dev)
@@ -1778,7 +1778,7 @@ int mlx5_eswitch_init(struct mlx5_core_dev *dev)
 	atomic64_set(&esw->offloads.num_flows, 0);
 	ida_init(&esw->offloads.vport_metadata_ida);
 	mutex_init(&esw->state_lock);
-	mutex_init(&esw->mode_lock);
+	init_rwsem(&esw->mode_lock);
 
 	mlx5_esw_for_all_vports(esw, i, vport) {
 		vport->vport = mlx5_eswitch_index_to_vport_num(esw, i);
@@ -1813,7 +1813,6 @@ void mlx5_eswitch_cleanup(struct mlx5_eswitch *esw)
 	esw->dev->priv.eswitch = NULL;
 	destroy_workqueue(esw->work_queue);
 	esw_offloads_cleanup_reps(esw);
-	mutex_destroy(&esw->mode_lock);
 	mutex_destroy(&esw->state_lock);
 	ida_destroy(&esw->offloads.vport_metadata_ida);
 	mlx5e_mod_hdr_tbl_destroy(&esw->offloads.mod_hdr);

drivers/net/ethernet/mellanox/mlx5/core/eswitch.h

@@ -262,7 +262,7 @@ struct mlx5_eswitch {
 	/* Protects eswitch mode change that occurs via one or more
 	 * user commands, i.e. sriov state change, devlink commands.
 	 */
-	struct mutex mode_lock;
+	struct rw_semaphore mode_lock;
 
 	struct {
 		bool            enabled;

drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c

@@ -2508,7 +2508,7 @@ int mlx5_devlink_eswitch_mode_set(struct devlink *devlink, u16 mode,
 	if (esw_mode_from_devlink(mode, &mlx5_mode))
 		return -EINVAL;
 
-	mutex_lock(&esw->mode_lock);
+	down_write(&esw->mode_lock);
 	cur_mlx5_mode = esw->mode;
 	if (cur_mlx5_mode == mlx5_mode)
 		goto unlock;
@@ -2521,7 +2521,7 @@ int mlx5_devlink_eswitch_mode_set(struct devlink *devlink, u16 mode,
 		err = -EINVAL;
 
 unlock:
-	mutex_unlock(&esw->mode_lock);
+	up_write(&esw->mode_lock);
 	return err;
 }
 
@@ -2534,14 +2534,14 @@ int mlx5_devlink_eswitch_mode_get(struct devlink *devlink, u16 *mode)
 	if (IS_ERR(esw))
 		return PTR_ERR(esw);
 
-	mutex_lock(&esw->mode_lock);
+	down_write(&esw->mode_lock);
 	err = eswitch_devlink_esw_mode_check(esw);
 	if (err)
 		goto unlock;
 
 	err = esw_mode_to_devlink(esw->mode, mode);
 unlock:
-	mutex_unlock(&esw->mode_lock);
+	up_write(&esw->mode_lock);
 	return err;
 }
 
@@ -2557,7 +2557,7 @@ int mlx5_devlink_eswitch_inline_mode_set(struct devlink *devlink, u8 mode,
 	if (IS_ERR(esw))
 		return PTR_ERR(esw);
 
-	mutex_lock(&esw->mode_lock);
+	down_write(&esw->mode_lock);
 	err = eswitch_devlink_esw_mode_check(esw);
 	if (err)
 		goto out;
@@ -2599,7 +2599,7 @@ int mlx5_devlink_eswitch_inline_mode_set(struct devlink *devlink, u8 mode,
 	}
 
 	esw->offloads.inline_mode = mlx5_mode;
-	mutex_unlock(&esw->mode_lock);
+	up_write(&esw->mode_lock);
 	return 0;
 
 revert_inline_mode:
@@ -2609,7 +2609,7 @@ int mlx5_devlink_eswitch_inline_mode_set(struct devlink *devlink, u8 mode,
 						 vport,
 						 esw->offloads.inline_mode);
 out:
-	mutex_unlock(&esw->mode_lock);
+	up_write(&esw->mode_lock);
 	return err;
 }
 
@@ -2622,14 +2622,14 @@ int mlx5_devlink_eswitch_inline_mode_get(struct devlink *devlink, u8 *mode)
 	if (IS_ERR(esw))
 		return PTR_ERR(esw);
 
-	mutex_lock(&esw->mode_lock);
+	down_write(&esw->mode_lock);
 	err = eswitch_devlink_esw_mode_check(esw);
 	if (err)
 		goto unlock;
 
 	err = esw_inline_mode_to_devlink(esw->offloads.inline_mode, mode);
 unlock:
-	mutex_unlock(&esw->mode_lock);
+	up_write(&esw->mode_lock);
 	return err;
 }
 
@@ -2645,7 +2645,7 @@ int mlx5_devlink_eswitch_encap_mode_set(struct devlink *devlink,
 	if (IS_ERR(esw))
 		return PTR_ERR(esw);
 
-	mutex_lock(&esw->mode_lock);
+	down_write(&esw->mode_lock);
 	err = eswitch_devlink_esw_mode_check(esw);
 	if (err)
 		goto unlock;
@@ -2691,7 +2691,7 @@ int mlx5_devlink_eswitch_encap_mode_set(struct devlink *devlink,
 	}
 
 unlock:
-	mutex_unlock(&esw->mode_lock);
+	up_write(&esw->mode_lock);
 	return err;
 }
 
@@ -2706,14 +2706,14 @@ int mlx5_devlink_eswitch_encap_mode_get(struct devlink *devlink,
 		return PTR_ERR(esw);
 
 
-	mutex_lock(&esw->mode_lock);
+	down_write(&esw->mode_lock);
 	err = eswitch_devlink_esw_mode_check(esw);
 	if (err)
 		goto unlock;
 
 	*encap = esw->offloads.encap;
 unlock:
-	mutex_unlock(&esw->mode_lock);
+	up_write(&esw->mode_lock);
 	return 0;
 }