From c6e36d8c1a76be7a7afa2669483857dadec1e99c Mon Sep 17 00:00:00 2001 From: Yuval Mintz Date: Mon, 1 Jun 2015 15:08:18 +0300 Subject: [PATCH] bnx2x: Move statistics implementation into semaphores Commit dff173de84958 ("bnx2x: Fix statistics locking scheme") changed the bnx2x locking around statistics state into using a mutex - but the lock is being accessed via a timer which is forbidden. [If compiled with CONFIG_DEBUG_MUTEXES, logs show a warning about accessing the mutex in interrupt context] This moves the implementation into using a semaphore [with size '1'] instead. Signed-off-by: Yuval Mintz Signed-off-by: Ariel Elior Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/bnx2x/bnx2x.h | 2 +- drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c | 9 +++++---- drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c | 20 ++++++++++++++------ 3 files changed, 20 insertions(+), 11 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h index a3b0f7a..1f82a04 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h @@ -1774,7 +1774,7 @@ struct bnx2x { int stats_state; /* used for synchronization of concurrent threads statistics handling */ - struct mutex stats_lock; + struct semaphore stats_lock; /* used by dmae command loader */ struct dmae_command stats_dmae; diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c index fd52ce9..33501bc 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c @@ -12054,7 +12054,7 @@ static int bnx2x_init_bp(struct bnx2x *bp) mutex_init(&bp->port.phy_mutex); mutex_init(&bp->fw_mb_mutex); mutex_init(&bp->drv_info_mutex); - mutex_init(&bp->stats_lock); + sema_init(&bp->stats_lock, 1); bp->drv_info_mng_owner = false; INIT_DELAYED_WORK(&bp->sp_task, bnx2x_sp_task); @@ -13690,9 +13690,10 @@ static int bnx2x_eeh_nic_unload(struct bnx2x *bp) cancel_delayed_work_sync(&bp->sp_task); cancel_delayed_work_sync(&bp->period_task); - mutex_lock(&bp->stats_lock); - bp->stats_state = STATS_STATE_DISABLED; - mutex_unlock(&bp->stats_lock); + if (!down_timeout(&bp->stats_lock, HZ / 10)) { + bp->stats_state = STATS_STATE_DISABLED; + up(&bp->stats_lock); + } bnx2x_save_statistics(bp); diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c index 266b055..69d699f0 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c @@ -1372,19 +1372,23 @@ void bnx2x_stats_handle(struct bnx2x *bp, enum bnx2x_stats_event event) * that context in case someone is in the middle of a transition. * For other events, wait a bit until lock is taken. */ - if (!mutex_trylock(&bp->stats_lock)) { + if (down_trylock(&bp->stats_lock)) { if (event == STATS_EVENT_UPDATE) return; DP(BNX2X_MSG_STATS, "Unlikely stats' lock contention [event %d]\n", event); - mutex_lock(&bp->stats_lock); + if (unlikely(down_timeout(&bp->stats_lock, HZ / 10))) { + BNX2X_ERR("Failed to take stats lock [event %d]\n", + event); + return; + } } bnx2x_stats_stm[state][event].action(bp); bp->stats_state = bnx2x_stats_stm[state][event].next_state; - mutex_unlock(&bp->stats_lock); + up(&bp->stats_lock); if ((event != STATS_EVENT_UPDATE) || netif_msg_timer(bp)) DP(BNX2X_MSG_STATS, "state %d -> event %d -> state %d\n", @@ -1970,7 +1974,11 @@ int bnx2x_stats_safe_exec(struct bnx2x *bp, /* Wait for statistics to end [while blocking further requests], * then run supplied function 'safely'. */ - mutex_lock(&bp->stats_lock); + rc = down_timeout(&bp->stats_lock, HZ / 10); + if (unlikely(rc)) { + BNX2X_ERR("Failed to take statistics lock for safe execution\n"); + goto out_no_lock; + } bnx2x_stats_comp(bp); while (bp->stats_pending && cnt--) @@ -1988,7 +1996,7 @@ out: /* No need to restart statistics - if they're enabled, the timer * will restart the statistics. */ - mutex_unlock(&bp->stats_lock); - + up(&bp->stats_lock); +out_no_lock: return rc; } -- 2.7.4