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Commit 64044bcf authored by Roland Dreier's avatar Roland Dreier
Browse files

[IB] mthca: fix wraparound handling in mthca_cq_clean() 



Handle case where prod_index has wrapped around and become less than
cq->cons_index by checking that their difference as a signed int is
positive rather than comparing directly.

Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent 62abb841

drivers/infiniband/hw/mthca/mthca_cq.c

+6 −10
Original line number Diff line number Diff line
@@ -258,7 +258,7 @@ void mthca_cq_clean(struct mthca_dev *dev, u32 cqn, u32 qpn, 
{

	struct mthca_cq *cq;

	struct mthca_cqe *cqe;

	int prod_index;

	u32 prod_index;

	int nfreed = 0;



	spin_lock_irq(&dev->cq_table.lock);
@@ -293,19 +293,15 @@ void mthca_cq_clean(struct mthca_dev *dev, u32 cqn, u32 qpn, 
	 * Now sweep backwards through the CQ, removing CQ entries

	 * that match our QP by copying older entries on top of them.

	 */

	while (prod_index > cq->cons_index) {

		cqe = get_cqe(cq, (prod_index - 1) & cq->ibcq.cqe);

	while ((int) --prod_index - (int) cq->cons_index >= 0) {

		cqe = get_cqe(cq, prod_index & cq->ibcq.cqe);

		if (cqe->my_qpn == cpu_to_be32(qpn)) {

			if (srq)

				mthca_free_srq_wqe(srq, be32_to_cpu(cqe->wqe));

			++nfreed;

		}

		else if (nfreed)

			memcpy(get_cqe(cq, (prod_index - 1 + nfreed) &

				       cq->ibcq.cqe),

			       cqe,

			       MTHCA_CQ_ENTRY_SIZE);

		--prod_index;

		} else if (nfreed)

			memcpy(get_cqe(cq, (prod_index + nfreed) & cq->ibcq.cqe),

			       cqe, MTHCA_CQ_ENTRY_SIZE);

	}



	if (nfreed) {