From 366ce60315292a579b8ceae2777102e1954a2024 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Sun, 10 Jan 2016 09:32:16 +0100 Subject: [PATCH] mlxsw: spectrum: Add FDB lock to prevent session interleaving Dumping the FDB (invoked with a process context) or handling FDB notifications (polled periodicly in delayed work) might each entail multiple EMAD transcations due to the number of entries. While we only allow one EMAD transaction at a time, there is nothing stopping the dump and notification processing sessions from interleaving. However, this is forbidden by the hardware, so we need to make sure only one of these sessions can run at a time. Solve this by adding a mutex ('fdb_lock'), as both kernel threads can sleep while waiting for the response EMAD. Fixes: 56ade8fe3f ("mlxsw: spectrum: Add initial support for Spectrum ASIC") Signed-off-by: Ido Schimmel Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlxsw/spectrum.h | 1 + drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h index 4365c8bccc6d..69281ca534b1 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h @@ -63,6 +63,7 @@ struct mlxsw_sp { } fdb_notify; #define MLXSW_SP_DEFAULT_AGEING_TIME 300 u32 ageing_time; + struct mutex fdb_lock; /* Make sure FDB sessions are atomic. */ struct { struct net_device *dev; unsigned int ref_count; diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c index 617fb22b5d81..80e266063aee 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c @@ -650,6 +650,7 @@ static int mlxsw_sp_port_fdb_dump(struct mlxsw_sp_port *mlxsw_sp_port, if (!sfd_pl) return -ENOMEM; + mutex_lock(&mlxsw_sp_port->mlxsw_sp->fdb_lock); mlxsw_reg_sfd_pack(sfd_pl, MLXSW_REG_SFD_OP_QUERY_DUMP, 0); do { mlxsw_reg_sfd_num_rec_set(sfd_pl, MLXSW_REG_SFD_REC_MAX_COUNT); @@ -684,6 +685,7 @@ static int mlxsw_sp_port_fdb_dump(struct mlxsw_sp_port *mlxsw_sp_port, } while (num_rec == MLXSW_REG_SFD_REC_MAX_COUNT); out: + mutex_unlock(&mlxsw_sp_port->mlxsw_sp->fdb_lock); kfree(sfd_pl); return stored_err ? stored_err : err; } @@ -812,6 +814,7 @@ static void mlxsw_sp_fdb_notify_work(struct work_struct *work) mlxsw_sp = container_of(work, struct mlxsw_sp, fdb_notify.dw.work); + mutex_lock(&mlxsw_sp->fdb_lock); do { mlxsw_reg_sfn_pack(sfn_pl); err = mlxsw_reg_query(mlxsw_sp->core, MLXSW_REG(sfn), sfn_pl); @@ -824,6 +827,7 @@ static void mlxsw_sp_fdb_notify_work(struct work_struct *work) mlxsw_sp_fdb_notify_rec_process(mlxsw_sp, sfn_pl, i); } while (num_rec); + mutex_unlock(&mlxsw_sp->fdb_lock); kfree(sfn_pl); mlxsw_sp_fdb_notify_work_schedule(mlxsw_sp); @@ -838,6 +842,7 @@ static int mlxsw_sp_fdb_init(struct mlxsw_sp *mlxsw_sp) dev_err(mlxsw_sp->bus_info->dev, "Failed to set default ageing time\n"); return err; } + mutex_init(&mlxsw_sp->fdb_lock); INIT_DELAYED_WORK(&mlxsw_sp->fdb_notify.dw, mlxsw_sp_fdb_notify_work); mlxsw_sp->fdb_notify.interval = MLXSW_SP_DEFAULT_LEARNING_INTERVAL; mlxsw_sp_fdb_notify_work_schedule(mlxsw_sp); -- 2.20.1