From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 550B0C43334 for ; Mon, 11 Jul 2022 08:14:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229826AbiGKIOj (ORCPT ); Mon, 11 Jul 2022 04:14:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50992 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229800AbiGKIOX (ORCPT ); Mon, 11 Jul 2022 04:14:23 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D8BB1D32B for ; Mon, 11 Jul 2022 01:14:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id ED7CDB80E3A for ; Mon, 11 Jul 2022 08:14:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B202C34115; Mon, 11 Jul 2022 08:14:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657527259; bh=JZ5JDeLwdavccmf9dp69ILOu2H3dhUsI87J3uOuJdXM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o/ZY7u3dnCdsdOr+QKqZhW1yFFD71eGcjjN39K6FBhrE5oa/mvud7ibkajuUknfgq 6SMZpUxBKVnQcronGq2eGdC9RhwaRcEE0Anj6s0joDo3+7Dx74J2CFHLEKWNWE3xno Zj1lJLSDLxkAbpQrjjFQzNc56dDfcAZ6qZyM3KJnuIO38YDTeGl5QGB3G+W9TEEpJz gYrnODSjz0tqyNmH/0appEphBALfcmVu1pZT0e2/mxNs+8sxLcgCsU7fgWi+jJpVy7 /3joou1V31E5IBe7H7giyvk/Sokbq3vW5SVqpPfkOhUW1DGlUB6AaAtik/RN2c6uZi 3SCoTt05ANUxQ== From: Saeed Mahameed To: "David S. Miller" , Jakub Kicinski , Paolo Abeni , Eric Dumazet Cc: Saeed Mahameed , netdev@vger.kernel.org, Moshe Shemesh Subject: [PATCH net-next 7/9] net/mlx5: Use devl_ API in mlx5e_devlink_port_register Date: Mon, 11 Jul 2022 01:14:06 -0700 Message-Id: <20220711081408.69452-8-saeed@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220711081408.69452-1-saeed@kernel.org> References: <20220711081408.69452-1-saeed@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Moshe Shemesh As part of the flows invoked by mlx5_devlink_eswitch_mode_set() get to mlx5_rescan_drivers_locked() which can call mlx5e_probe()/mlx5e_remove and register/unregister mlx5e driver ports accordingly. This can lead to deadlock once mlx5_devlink_eswitch_mode_set() will use devlink lock. Use devl_port_register/unregister() instead of devlink_port_register/unregister() and add devlink instance locks in the driver paths to this function to have it locked while calling devl_ API function. If remove or probe were called by module init or module cleanup flows, need to lock devlink just before calling devl_port_register(), otherwise it is called by attach/detach or register/unregister flow and we can have the flow locked. Added flag to distinguish between these cases. This will be used by the downstream patch to invoke mlx5_devlink_eswitch_mode_set() with devlink locked. Signed-off-by: Moshe Shemesh Signed-off-by: Saeed Mahameed --- drivers/net/ethernet/mellanox/mlx5/core/dev.c | 29 +++++++++++++++++-- .../ethernet/mellanox/mlx5/core/en/devlink.c | 16 ++++++++-- .../mellanox/mlx5/core/eswitch_offloads.c | 2 ++ include/linux/mlx5/driver.h | 4 +++ 4 files changed, 47 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/dev.c b/drivers/net/ethernet/mellanox/mlx5/core/dev.c index 50422b56a64d..ccf2068d2e79 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/dev.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/dev.c @@ -335,13 +335,16 @@ static void del_adev(struct auxiliary_device *adev) int mlx5_attach_device(struct mlx5_core_dev *dev) { + struct devlink *devlink = priv_to_devlink(dev); struct mlx5_priv *priv = &dev->priv; struct auxiliary_device *adev; struct auxiliary_driver *adrv; int ret = 0, i; + devl_lock(devlink); mutex_lock(&mlx5_intf_mutex); priv->flags &= ~MLX5_PRIV_FLAGS_DETACH; + priv->flags |= MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW; for (i = 0; i < ARRAY_SIZE(mlx5_adev_devices); i++) { if (!priv->adev[i]) { bool is_supported = false; @@ -389,19 +392,24 @@ int mlx5_attach_device(struct mlx5_core_dev *dev) break; } } + priv->flags &= ~MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW; mutex_unlock(&mlx5_intf_mutex); + devl_unlock(devlink); return ret; } void mlx5_detach_device(struct mlx5_core_dev *dev) { + struct devlink *devlink = priv_to_devlink(dev); struct mlx5_priv *priv = &dev->priv; struct auxiliary_device *adev; struct auxiliary_driver *adrv; pm_message_t pm = {}; int i; + devl_lock(devlink); mutex_lock(&mlx5_intf_mutex); + priv->flags |= MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW; for (i = ARRAY_SIZE(mlx5_adev_devices) - 1; i >= 0; i--) { if (!priv->adev[i]) continue; @@ -430,18 +438,24 @@ void mlx5_detach_device(struct mlx5_core_dev *dev) del_adev(&priv->adev[i]->adev); priv->adev[i] = NULL; } + priv->flags &= ~MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW; priv->flags |= MLX5_PRIV_FLAGS_DETACH; mutex_unlock(&mlx5_intf_mutex); + devl_unlock(devlink); } int mlx5_register_device(struct mlx5_core_dev *dev) { + struct devlink *devlink; int ret; + devlink = priv_to_devlink(dev); + devl_lock(devlink); mutex_lock(&mlx5_intf_mutex); dev->priv.flags &= ~MLX5_PRIV_FLAGS_DISABLE_ALL_ADEV; ret = mlx5_rescan_drivers_locked(dev); mutex_unlock(&mlx5_intf_mutex); + devl_unlock(devlink); if (ret) mlx5_unregister_device(dev); @@ -450,10 +464,15 @@ int mlx5_register_device(struct mlx5_core_dev *dev) void mlx5_unregister_device(struct mlx5_core_dev *dev) { + struct devlink *devlink; + + devlink = priv_to_devlink(dev); + devl_lock(devlink); mutex_lock(&mlx5_intf_mutex); dev->priv.flags = MLX5_PRIV_FLAGS_DISABLE_ALL_ADEV; mlx5_rescan_drivers_locked(dev); mutex_unlock(&mlx5_intf_mutex); + devl_unlock(devlink); } static int add_drivers(struct mlx5_core_dev *dev) @@ -526,16 +545,22 @@ static void delete_drivers(struct mlx5_core_dev *dev) int mlx5_rescan_drivers_locked(struct mlx5_core_dev *dev) { struct mlx5_priv *priv = &dev->priv; + int err = 0; lockdep_assert_held(&mlx5_intf_mutex); if (priv->flags & MLX5_PRIV_FLAGS_DETACH) return 0; + priv->flags |= MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW; delete_drivers(dev); if (priv->flags & MLX5_PRIV_FLAGS_DISABLE_ALL_ADEV) - return 0; + goto out; + + err = add_drivers(dev); - return add_drivers(dev); +out: + priv->flags &= ~MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW; + return err; } bool mlx5_same_hw_devs(struct mlx5_core_dev *dev, struct mlx5_core_dev *peer_dev) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/en/devlink.c index ae52e7f38306..b69f9d10ccbd 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/devlink.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/devlink.c @@ -21,6 +21,7 @@ int mlx5e_devlink_port_register(struct mlx5e_priv *priv) struct netdev_phys_item_id ppid = {}; struct devlink_port *dl_port; unsigned int dl_port_index; + int ret; if (mlx5_core_is_pf(priv->mdev)) { attrs.flavour = DEVLINK_PORT_FLAVOUR_PHYSICAL; @@ -41,7 +42,13 @@ int mlx5e_devlink_port_register(struct mlx5e_priv *priv) memset(dl_port, 0, sizeof(*dl_port)); devlink_port_attrs_set(dl_port, &attrs); - return devlink_port_register(devlink, dl_port, dl_port_index); + if (!(priv->mdev->priv.flags & MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW)) + devl_lock(devlink); + ret = devl_port_register(devlink, dl_port, dl_port_index); + if (!(priv->mdev->priv.flags & MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW)) + devl_unlock(devlink); + + return ret; } void mlx5e_devlink_port_type_eth_set(struct mlx5e_priv *priv) @@ -54,8 +61,13 @@ void mlx5e_devlink_port_type_eth_set(struct mlx5e_priv *priv) void mlx5e_devlink_port_unregister(struct mlx5e_priv *priv) { struct devlink_port *dl_port = mlx5e_devlink_get_dl_port(priv); + struct devlink *devlink = priv_to_devlink(priv->mdev); - devlink_port_unregister(dl_port); + if (!(priv->mdev->priv.flags & MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW)) + devl_lock(devlink); + devl_port_unregister(dl_port); + if (!(priv->mdev->priv.flags & MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW)) + devl_unlock(devlink); } struct devlink_port *mlx5e_get_devlink_port(struct net_device *dev) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c index 1bfbc88f513f..ccda3a0a2594 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c @@ -3400,7 +3400,9 @@ int mlx5_devlink_eswitch_mode_set(struct devlink *devlink, u16 mode, err = esw_offloads_start(esw, extack); } else if (mode == DEVLINK_ESWITCH_MODE_LEGACY) { err = esw_offloads_stop(esw, extack); + devl_lock(devlink); mlx5_rescan_drivers(esw->dev); + devl_unlock(devlink); } else { err = -EINVAL; } diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h index 76d7661e3e63..bd882884b23c 100644 --- a/include/linux/mlx5/driver.h +++ b/include/linux/mlx5/driver.h @@ -551,6 +551,10 @@ enum { * creation/deletion on drivers rescan. Unset during device attach. */ MLX5_PRIV_FLAGS_DETACH = 1 << 2, + /* Distinguish between mlx5e_probe/remove called by module init/cleanup + * and called by other flows which can already hold devlink lock + */ + MLX5_PRIV_FLAGS_MLX5E_LOCKED_FLOW = 1 << 3, }; struct mlx5_adev { -- 2.36.1