Commit c6e36d8c authored by Yuval Mintz's avatar Yuval Mintz Committed by David S. Miller
Browse files

bnx2x: Move statistics implementation into semaphores

Commit dff173de

 ("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: default avatarYuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: default avatarAriel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 31a41898
......@@ -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;
......
......@@ -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);
......
......@@ -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;
}
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