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authorYuval Mintz <Yuval.Mintz@qlogic.com>2015-06-01 15:08:18 +0300
committerDavid S. Miller <davem@davemloft.net>2015-06-01 12:04:31 -0700
commitc6e36d8c1a76be7a7afa2669483857dadec1e99c (patch)
tree6ba06f3353eaff41b0a9ccc01d9418033a3e4ed5
parent31a418986a5852034d520a5bab546821ff1ccf3d (diff)
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 <Yuval.Mintz@qlogic.com> Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/broadcom/bnx2x/bnx2x.h2
-rw-r--r--drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c9
-rw-r--r--drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c20
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 a3b0f7a0c61e..1f82a04ce01a 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 fd52ce95127e..33501bcddc48 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 266b055c2360..69d699f0730a 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;
}