cxgb4: Use ACCES_ONCE macro to read queue's consumer index

Use helper macro ACCESS_ONCE() to load from the SGE status page
to prevent the compiler loading multiple times.

Based on original work by Mike Werner <werner@chelsio.com>

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Hariprasad Shenai 2015-12-08 10:09:13 +05:30 committed by David S. Miller
parent b8759e917e
commit 632be1942d

View File

@ -406,7 +406,7 @@ static void free_tx_desc(struct adapter *adap, struct sge_txq *q,
*/
static inline int reclaimable(const struct sge_txq *q)
{
int hw_cidx = ntohs(q->stat->cidx);
int hw_cidx = ntohs(ACCESS_ONCE(q->stat->cidx));
hw_cidx -= q->cidx;
return hw_cidx < 0 ? hw_cidx + q->size : hw_cidx;
}
@ -1320,7 +1320,7 @@ out_free: dev_kfree_skb_any(skb);
*/
static inline void reclaim_completed_tx_imm(struct sge_txq *q)
{
int hw_cidx = ntohs(q->stat->cidx);
int hw_cidx = ntohs(ACCESS_ONCE(q->stat->cidx));
int reclaim = hw_cidx - q->cidx;
if (reclaim < 0)