RDMA/cxgb4: rmb() after reading valid gen bit

Some HW platforms can reorder read operations, so we must rmb() after
we see a valid gen bit in a CQE but before we read any other fields
from the CQE.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
This commit is contained in:
Steve Wise 2014-04-09 09:38:26 -05:00 коммит произвёл Roland Dreier
Родитель b33bd0cbfa
Коммит def4771f4b
1 изменённых файлов: 3 добавлений и 0 удалений

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@ -620,6 +620,9 @@ static inline int t4_next_hw_cqe(struct t4_cq *cq, struct t4_cqe **cqe)
printk(KERN_ERR MOD "cq overflow cqid %u\n", cq->cqid);
BUG_ON(1);
} else if (t4_valid_cqe(cq, &cq->queue[cq->cidx])) {
/* Ensure CQE is flushed to memory */
rmb();
*cqe = &cq->queue[cq->cidx];
ret = 0;
} else