From a551ee94ea723b4af9b827c7460f108bc13425ee Mon Sep 17 00:00:00 2001 From: Michael Chan Date: Wed, 25 Jan 2017 02:55:07 -0500 Subject: [PATCH] bnxt_en: Fix bnxt_reset() in the slow path task. In bnxt_sp_task(), we set a bit BNXT_STATE_IN_SP_TASK so that bnxt_close() will synchronize and wait for bnxt_sp_task() to finish. Some functions in bnxt_sp_task() require us to clear BNXT_STATE_IN_SP_TASK and then acquire rtnl_lock() to prevent race conditions. There are some bugs related to this logic. This patch refactors the code to have common bnxt_rtnl_lock_sp() and bnxt_rtnl_unlock_sp() to handle the RTNL and the clearing/setting of the bit. Multiple functions will need the same logic. We also need to move bnxt_reset() to the end of bnxt_sp_task(). Functions that clear BNXT_STATE_IN_SP_TASK must be the last functions to be called in bnxt_sp_task(). The common scheme will handle the condition properly. Signed-off-by: Michael Chan Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 38 +++++++++++++++-------- 1 file changed, 25 insertions(+), 13 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index 53e686fdf2ce..30d7d643bdbe 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -6200,23 +6200,32 @@ bnxt_restart_timer: mod_timer(&bp->timer, jiffies + bp->current_interval); } -/* Only called from bnxt_sp_task() */ -static void bnxt_reset(struct bnxt *bp, bool silent) +static void bnxt_rtnl_lock_sp(struct bnxt *bp) { - /* bnxt_reset_task() calls bnxt_close_nic() which waits - * for BNXT_STATE_IN_SP_TASK to clear. - * If there is a parallel dev_close(), bnxt_close() may be holding + /* We are called from bnxt_sp_task which has BNXT_STATE_IN_SP_TASK + * set. If the device is being closed, bnxt_close() may be holding * rtnl() and waiting for BNXT_STATE_IN_SP_TASK to clear. So we * must clear BNXT_STATE_IN_SP_TASK before holding rtnl(). */ clear_bit(BNXT_STATE_IN_SP_TASK, &bp->state); rtnl_lock(); - if (test_bit(BNXT_STATE_OPEN, &bp->state)) - bnxt_reset_task(bp, silent); +} + +static void bnxt_rtnl_unlock_sp(struct bnxt *bp) +{ set_bit(BNXT_STATE_IN_SP_TASK, &bp->state); rtnl_unlock(); } +/* Only called from bnxt_sp_task() */ +static void bnxt_reset(struct bnxt *bp, bool silent) +{ + bnxt_rtnl_lock_sp(bp); + if (test_bit(BNXT_STATE_OPEN, &bp->state)) + bnxt_reset_task(bp, silent); + bnxt_rtnl_unlock_sp(bp); +} + static void bnxt_cfg_ntp_filters(struct bnxt *); static void bnxt_sp_task(struct work_struct *work) @@ -6266,18 +6275,21 @@ static void bnxt_sp_task(struct work_struct *work) bnxt_hwrm_tunnel_dst_port_free( bp, TUNNEL_DST_PORT_FREE_REQ_TUNNEL_TYPE_GENEVE); } - if (test_and_clear_bit(BNXT_RESET_TASK_SP_EVENT, &bp->sp_event)) - bnxt_reset(bp, false); - - if (test_and_clear_bit(BNXT_RESET_TASK_SILENT_SP_EVENT, &bp->sp_event)) - bnxt_reset(bp, true); - if (test_and_clear_bit(BNXT_HWRM_PORT_MODULE_SP_EVENT, &bp->sp_event)) bnxt_get_port_module_status(bp); if (test_and_clear_bit(BNXT_PERIODIC_STATS_SP_EVENT, &bp->sp_event)) bnxt_hwrm_port_qstats(bp); + /* These functions below will clear BNXT_STATE_IN_SP_TASK. They + * must be the last functions to be called before exiting. + */ + if (test_and_clear_bit(BNXT_RESET_TASK_SP_EVENT, &bp->sp_event)) + bnxt_reset(bp, false); + + if (test_and_clear_bit(BNXT_RESET_TASK_SILENT_SP_EVENT, &bp->sp_event)) + bnxt_reset(bp, true); + smp_mb__before_atomic(); clear_bit(BNXT_STATE_IN_SP_TASK, &bp->state); } -- 2.20.1