From 525e84bea52be145b0ae863ff8d242ce273e3bc6 Mon Sep 17 00:00:00 2001 From: Vlad Buslov Date: Sun, 18 Nov 2018 13:12:59 +0200 Subject: [PATCH] net/mlx5e: Eswitch, change offloads num_flows type to atomic64 Eswitch implements its own locking by means of state_lock mutex and multiple fine-grained lock in containing data structures, and is supposed to not rely on rtnl lock. However, eswitch offloads num_flows type is a regular long long integer and cannot be modified concurrently. This is an implicit assumptions that mlx5 tc is serialized (by rtnl lock or any other means). In order to remove implicit dependency on rtnl lock, change num_flows type to atomic64 to allow concurrent modifications. Signed-off-by: Vlad Buslov Reviewed-by: Jianbo Liu Reviewed-by: Roi Dayan Signed-off-by: Saeed Mahameed --- drivers/net/ethernet/mellanox/mlx5/core/eswitch.c | 1 + drivers/net/ethernet/mellanox/mlx5/core/eswitch.h | 3 ++- .../net/ethernet/mellanox/mlx5/core/eswitch_offloads.c | 10 +++++----- 3 files changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c index 1f3891fde2eb..d365551d2f10 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c @@ -1933,6 +1933,7 @@ int mlx5_eswitch_init(struct mlx5_core_dev *dev) hash_init(esw->offloads.encap_tbl); hash_init(esw->offloads.mod_hdr_tbl); + atomic64_set(&esw->offloads.num_flows, 0); mutex_init(&esw->state_lock); mlx5_esw_for_all_vports(esw, i, vport) { diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h index a38e8a3c7c9a..60f0c62b447b 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h @@ -35,6 +35,7 @@ #include #include +#include #include #include #include @@ -179,7 +180,7 @@ struct mlx5_esw_offload { struct mutex termtbl_mutex; /* protects termtbl hash */ const struct mlx5_eswitch_rep_ops *rep_ops[NUM_REP_TYPES]; u8 inline_mode; - u64 num_flows; + atomic64_t num_flows; enum devlink_eswitch_encap_mode encap; }; diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c index 089ae4d48a82..244ad1893691 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c @@ -233,7 +233,7 @@ mlx5_eswitch_add_offloaded_rule(struct mlx5_eswitch *esw, if (IS_ERR(rule)) goto err_add_rule; else - esw->offloads.num_flows++; + atomic64_inc(&esw->offloads.num_flows); return rule; @@ -298,7 +298,7 @@ mlx5_eswitch_add_fwd_rule(struct mlx5_eswitch *esw, if (IS_ERR(rule)) goto add_err; - esw->offloads.num_flows++; + atomic64_inc(&esw->offloads.num_flows); return rule; add_err: @@ -326,7 +326,7 @@ __mlx5_eswitch_del_rule(struct mlx5_eswitch *esw, mlx5_eswitch_termtbl_put(esw, attr->dests[i].termtbl); } - esw->offloads.num_flows--; + atomic64_dec(&esw->offloads.num_flows); if (fwd_rule) { esw_put_prio_table(esw, attr->chain, attr->prio, 1); @@ -2349,7 +2349,7 @@ int mlx5_devlink_eswitch_inline_mode_set(struct devlink *devlink, u8 mode, break; } - if (esw->offloads.num_flows > 0) { + if (atomic64_read(&esw->offloads.num_flows) > 0) { NL_SET_ERR_MSG_MOD(extack, "Can't set inline mode when flows are configured"); return -EOPNOTSUPP; @@ -2459,7 +2459,7 @@ int mlx5_devlink_eswitch_encap_mode_set(struct devlink *devlink, if (esw->offloads.encap == encap) return 0; - if (esw->offloads.num_flows > 0) { + if (atomic64_read(&esw->offloads.num_flows) > 0) { NL_SET_ERR_MSG_MOD(extack, "Can't set encapsulation when flows are configured"); return -EOPNOTSUPP; -- 2.30.2