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Commit fb0e76ab authored by Erik Stromdahl's avatar Erik Stromdahl Committed by Johannes Berg
Browse files

mac80211: add tx dequeue function for process context 



Since ieee80211_tx_dequeue() must not be called with softirqs enabled
(i.e. from process context without proper disable of bottom halves),
we add a wrapper that disables bottom halves before calling
ieee80211_tx_dequeue()

The new function is named ieee80211_tx_dequeue_ni() just as all other
from-process-context versions found in mac80211.

The documentation of ieee80211_tx_dequeue() is also updated so it
mentions that the function should not be called from process context.

Signed-off-by: default avatarErik Stromdahl <erik.stromdahl@gmail.com>
Link: https://lore.kernel.org/r/20190617200140.6189-1-erik.stromdahl@gmail.com


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent a11e2f85

include/net/mac80211.h

+26 −0
Original line number Diff line number Diff line
@@ -6234,10 +6234,36 @@ void ieee80211_unreserve_tid(struct ieee80211_sta *sta, u8 tid); 
 * but for the duration of the frame handling.

 * However, also note that while in the wake_tx_queue() method,

 * rcu_read_lock() is already held.

 *

 * softirqs must also be disabled when this function is called.

 * In process context, use ieee80211_tx_dequeue_ni() instead.

 */

struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw,

				     struct ieee80211_txq *txq);



/**

 * ieee80211_tx_dequeue_ni - dequeue a packet from a software tx queue

 * (in process context)

 *

 * Like ieee80211_tx_dequeue() but can be called in process context

 * (internally disables bottom halves).

 *

 * @hw: pointer as obtained from ieee80211_alloc_hw()

 * @txq: pointer obtained from station or virtual interface, or from

 *	ieee80211_next_txq()

 */

static inline struct sk_buff *ieee80211_tx_dequeue_ni(struct ieee80211_hw *hw,

						      struct ieee80211_txq *txq)

{

	struct sk_buff *skb;



	local_bh_disable();

	skb = ieee80211_tx_dequeue(hw, txq);

	local_bh_enable();



	return skb;

}



/**

 * ieee80211_next_txq - get next tx queue to pull packets from

 *

net/mac80211/tx.c

+2 −0
Original line number Diff line number Diff line
@@ -3546,6 +3546,8 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw, 
	ieee80211_tx_result r;

	struct ieee80211_vif *vif = txq->vif;



	WARN_ON_ONCE(softirq_count() == 0);



begin:

	spin_lock_bh(&fq->lock);