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Commit 27d9ce4f authored by Jacob Keller's avatar Jacob Keller Committed by Jeff Kirsher
Browse files

ixgbe: fix qv_lock_napi call in ixgbe_napi_disable_all 



ixgbe_napi_disable_all calls napi_disable on each queue, however the busy
polling code introduced a local_bh_disable()d context around the napi_disable.
The original author did not realize that napi_disable might sleep, which would
cause a sleep while atomic BUG. In addition, on a single processor system, the
ixgbe_qv_lock_napi loop shouldn't have to mdelay. This patch adds an
ixgbe_qv_disable along with a new IXGBE_QV_STATE_DISABLED bit, which it uses to
indicate to the poll and napi routines that the q_vector has been disabled. Now
the ixgbe_napi_disable_all function will wait until all pending work has been
finished and prevent any future work from being started.

Signed-off-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Cc: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Cc: Alexander Duyck <alexander.duyck@intel.com>
Cc: Hyong-Youb Kim <hykim@myri.com>
Cc: Amir Vadai <amirv@mellanox.com>
Cc: Dmitry Kravkov <dmitry@broadcom.com>
Tested-by: default avatarPhil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent 80c33ddd

drivers/net/ethernet/intel/ixgbe/ixgbe.h

+36 −12
Original line number Diff line number Diff line
@@ -371,9 +371,11 @@ struct ixgbe_q_vector { 
#define IXGBE_QV_STATE_IDLE        0

#define IXGBE_QV_STATE_NAPI	   1     /* NAPI owns this QV */

#define IXGBE_QV_STATE_POLL	   2     /* poll owns this QV */

#define IXGBE_QV_LOCKED (IXGBE_QV_STATE_NAPI | IXGBE_QV_STATE_POLL)

#define IXGBE_QV_STATE_NAPI_YIELD  4    /* NAPI yielded this QV */

#define IXGBE_QV_STATE_POLL_YIELD  8    /* poll yielded this QV */

#define IXGBE_QV_STATE_DISABLED	   4     /* QV is disabled */

#define IXGBE_QV_OWNED (IXGBE_QV_STATE_NAPI | IXGBE_QV_STATE_POLL)

#define IXGBE_QV_LOCKED (IXGBE_QV_OWNED | IXGBE_QV_STATE_DISABLED)

#define IXGBE_QV_STATE_NAPI_YIELD  8     /* NAPI yielded this QV */

#define IXGBE_QV_STATE_POLL_YIELD  16    /* poll yielded this QV */

#define IXGBE_QV_YIELD (IXGBE_QV_STATE_NAPI_YIELD | IXGBE_QV_STATE_POLL_YIELD)

#define IXGBE_QV_USER_PEND (IXGBE_QV_STATE_POLL | IXGBE_QV_STATE_POLL_YIELD)

	spinlock_t lock;
@@ -394,7 +396,7 @@ static inline void ixgbe_qv_init_lock(struct ixgbe_q_vector *q_vector) 
static inline bool ixgbe_qv_lock_napi(struct ixgbe_q_vector *q_vector)

{

	int rc = true;

	spin_lock(&q_vector->lock);

	spin_lock_bh(&q_vector->lock);

	if (q_vector->state & IXGBE_QV_LOCKED) {

		WARN_ON(q_vector->state & IXGBE_QV_STATE_NAPI);

		q_vector->state |= IXGBE_QV_STATE_NAPI_YIELD;
@@ -405,7 +407,7 @@ static inline bool ixgbe_qv_lock_napi(struct ixgbe_q_vector *q_vector) 
	} else

		/* we don't care if someone yielded */

		q_vector->state = IXGBE_QV_STATE_NAPI;

	spin_unlock(&q_vector->lock);

	spin_unlock_bh(&q_vector->lock);

	return rc;

}
@@ -413,14 +415,15 @@ static inline bool ixgbe_qv_lock_napi(struct ixgbe_q_vector *q_vector) 
static inline bool ixgbe_qv_unlock_napi(struct ixgbe_q_vector *q_vector)

{

	int rc = false;

	spin_lock(&q_vector->lock);

	spin_lock_bh(&q_vector->lock);

	WARN_ON(q_vector->state & (IXGBE_QV_STATE_POLL |

			       IXGBE_QV_STATE_NAPI_YIELD));



	if (q_vector->state & IXGBE_QV_STATE_POLL_YIELD)

		rc = true;

	q_vector->state = IXGBE_QV_STATE_IDLE;

	spin_unlock(&q_vector->lock);

	/* will reset state to idle, unless QV is disabled */

	q_vector->state &= IXGBE_QV_STATE_DISABLED;

	spin_unlock_bh(&q_vector->lock);

	return rc;

}
@@ -451,7 +454,8 @@ static inline bool ixgbe_qv_unlock_poll(struct ixgbe_q_vector *q_vector) 


	if (q_vector->state & IXGBE_QV_STATE_POLL_YIELD)

		rc = true;

	q_vector->state = IXGBE_QV_STATE_IDLE;

	/* will reset state to idle, unless QV is disabled */

	q_vector->state &= IXGBE_QV_STATE_DISABLED;

	spin_unlock_bh(&q_vector->lock);

	return rc;

}
@@ -459,9 +463,23 @@ static inline bool ixgbe_qv_unlock_poll(struct ixgbe_q_vector *q_vector) 
/* true if a socket is polling, even if it did not get the lock */

static inline bool ixgbe_qv_busy_polling(struct ixgbe_q_vector *q_vector)

{

	WARN_ON(!(q_vector->state & IXGBE_QV_LOCKED));

	WARN_ON(!(q_vector->state & IXGBE_QV_OWNED));

	return q_vector->state & IXGBE_QV_USER_PEND;

}



/* false if QV is currently owned */

static inline bool ixgbe_qv_disable(struct ixgbe_q_vector *q_vector)

{

	int rc = true;

	spin_lock_bh(&q_vector->lock);

	if (q_vector->state & IXGBE_QV_OWNED)

		rc = false;

	q_vector->state |= IXGBE_QV_STATE_DISABLED;

	spin_unlock_bh(&q_vector->lock);



	return rc;

}



#else /* CONFIG_NET_RX_BUSY_POLL */

static inline void ixgbe_qv_init_lock(struct ixgbe_q_vector *q_vector)

{
@@ -491,6 +509,12 @@ static inline bool ixgbe_qv_busy_polling(struct ixgbe_q_vector *q_vector) 
{

	return false;

}



static inline bool ixgbe_qv_disable(struct ixgbe_q_vector *q_vector)

{

	return true;

}



#endif /* CONFIG_NET_RX_BUSY_POLL */



#ifdef CONFIG_IXGBE_HWMON

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

+2 −4
Original line number Diff line number Diff line
@@ -3891,15 +3891,13 @@ static void ixgbe_napi_disable_all(struct ixgbe_adapter *adapter) 
{

	int q_idx;



	local_bh_disable(); /* for ixgbe_qv_lock_napi() */

	for (q_idx = 0; q_idx < adapter->num_q_vectors; q_idx++) {

		napi_disable(&adapter->q_vector[q_idx]->napi);

		while (!ixgbe_qv_lock_napi(adapter->q_vector[q_idx])) {

		while (!ixgbe_qv_disable(adapter->q_vector[q_idx])) {

			pr_info("QV %d locked\n", q_idx);

			mdelay(1);

			usleep_range(1000, 20000);

		}

	}

	local_bh_enable();

}



#ifdef CONFIG_IXGBE_DCB