Commit def4771f authored by Steve Wise's avatar Steve Wise Committed by Roland Dreier
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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: default avatarSteve Wise <swise@opengridcomputing.com>
Signed-off-by: default avatarRoland Dreier <roland@purestorage.com>
parent b33bd0cb

drivers/infiniband/hw/cxgb4/t4.h

+3 −0
Original line number Diff line number Diff line
@@ -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