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Commit 9b40183c authored by Somnath Kotur's avatar Somnath Kotur Committed by Doug Ledford
Browse files

RDMA/bnxt_re: Add memory barriers when processing CQ/EQ entries 



The code determines if the next ring entry is valid before proceeding
further to read the rest of the entry. The CPU can re-order and read
the rest of the entry first, possibly reading a stale entry, if DMA
of a new entry happens right after reading it.

Signed-off-by: default avatarSomnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: default avatarSelvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent 685894dd

drivers/infiniband/hw/bnxt_re/qplib_fp.c

+21 −0
Original line number Diff line number Diff line
@@ -292,6 +292,12 @@ static void bnxt_qplib_service_nq(unsigned long data) 
		if (!NQE_CMP_VALID(nqe, raw_cons, hwq->max_elements))

			break;



		/*

		 * The valid test of the entry must be done first before

		 * reading any further.

		 */

		dma_rmb();



		type = le16_to_cpu(nqe->info10_type) & NQ_BASE_TYPE_MASK;

		switch (type) {

		case NQ_BASE_TYPE_CQ_NOTIFICATION:
@@ -1113,6 +1119,11 @@ static void __clean_cq(struct bnxt_qplib_cq *cq, u64 qp) 
		hw_cqe = &hw_cqe_ptr[CQE_PG(i)][CQE_IDX(i)];

		if (!CQE_CMP_VALID(hw_cqe, i, cq_hwq->max_elements))

			continue;

		/*

		 * The valid test of the entry must be done first before

		 * reading any further.

		 */

		dma_rmb();

		switch (hw_cqe->cqe_type_toggle & CQ_BASE_CQE_TYPE_MASK) {

		case CQ_BASE_CQE_TYPE_REQ:

		case CQ_BASE_CQE_TYPE_TERMINAL:
@@ -1896,6 +1907,11 @@ static int do_wa9060(struct bnxt_qplib_qp *qp, struct bnxt_qplib_cq *cq, 
			/* If the next hwcqe is VALID */

			if (CQE_CMP_VALID(peek_hwcqe, peek_raw_cq_cons,

					  cq->hwq.max_elements)) {

			/*

			 * The valid test of the entry must be done first before

			 * reading any further.

			 */

				dma_rmb();

				/* If the next hwcqe is a REQ */

				if ((peek_hwcqe->cqe_type_toggle &

				    CQ_BASE_CQE_TYPE_MASK) ==
@@ -2440,6 +2456,11 @@ int bnxt_qplib_poll_cq(struct bnxt_qplib_cq *cq, struct bnxt_qplib_cqe *cqe, 
		if (!CQE_CMP_VALID(hw_cqe, raw_cons, cq->hwq.max_elements))

			break;



		/*

		 * The valid test of the entry must be done first before

		 * reading any further.

		 */

		dma_rmb();

		/* From the device's respective CQE format to qplib_wc*/

		switch (hw_cqe->cqe_type_toggle & CQ_BASE_CQE_TYPE_MASK) {

		case CQ_BASE_CQE_TYPE_REQ:

drivers/infiniband/hw/bnxt_re/qplib_rcfw.c

+4 −0
Original line number Diff line number Diff line
@@ -359,6 +359,10 @@ static void bnxt_qplib_service_creq(unsigned long data) 
		creqe = &creq_ptr[get_creq_pg(sw_cons)][get_creq_idx(sw_cons)];

		if (!CREQ_CMP_VALID(creqe, raw_cons, creq->max_elements))

			break;

		/* The valid test of the entry must be done first before

		 * reading any further.

		 */

		dma_rmb();



		type = creqe->type & CREQ_BASE_TYPE_MASK;

		switch (type) {