[openib-general] [PATCH] mthca: fix posting long send lists on arbel

[Michael S. Tsirkin]

mthca: fix posting send work request lists of length >= 255 on Arbel.

Signed-off-by: Michael S. Tsirkin <mst at mellanox.co.il>

Index: linux-kernel/drivers/infiniband/hw/mthca/mthca_wqe.h
===================================================================
--- linux-kernel/drivers/infiniband/hw/mthca/mthca_wqe.h	(revision 4088)
+++ linux-kernel/drivers/infiniband/hw/mthca/mthca_wqe.h	(working copy)
@@ -50,7 +50,8 @@ enum {
 
 enum {
 	MTHCA_INVAL_LKEY			= 0x100,
-	MTHCA_TAVOR_MAX_WQES_PER_RECV_DB	= 256
+	MTHCA_TAVOR_MAX_WQES_PER_RECV_DB	= 256,
+	MTHCA_ARBEL_MAX_WQES_PER_SEND_DB	= 255
 };
 
 struct mthca_next_seg {
Index: linux-kernel/drivers/infiniband/hw/mthca/mthca_qp.c
===================================================================
--- linux-kernel/drivers/infiniband/hw/mthca/mthca_qp.c	(revision 4088)
+++ linux-kernel/drivers/infiniband/hw/mthca/mthca_qp.c	(working copy)
@@ -1836,6 +1881,34 @@ int mthca_arbel_post_send(struct ib_qp *
 	ind = qp->sq.head & (qp->sq.max - 1);
 
 	for (nreq = 0; wr; ++nreq, wr = wr->next) {
+		if (unlikely(nreq == MTHCA_ARBEL_MAX_WQES_PER_SEND_DB)) {
+			__be32 doorbell[2];
+			nreq = 0;
+			doorbell[0] = cpu_to_be32((MTHCA_ARBEL_MAX_WQES_PER_SEND_DB << 24) |
+						  ((qp->sq.head & 0xffff) << 8) |
+						  f0 | op0);
+			doorbell[1] = cpu_to_be32((qp->qpn << 8) | size0);
+			size0 = 0;
+
+			qp->sq.head += MTHCA_ARBEL_MAX_WQES_PER_SEND_DB;
+
+			/*
+			 * Make sure that descriptors are written before
+			 * doorbell record.
+			 */
+			wmb();
+			*qp->sq.db = cpu_to_be32(qp->sq.head & 0xffff);
+
+			/*
+			 * Make sure doorbell record is written before we
+			 * write MMIO send doorbell.
+			 */
+			wmb();
+			mthca_write64(doorbell,
+				      dev->kar + MTHCA_SEND_DOORBELL,
+				      MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
+		}
+
 		if (mthca_wq_overflow(&qp->sq, nreq, qp->ibqp.send_cq)) {
 			mthca_err(dev, "SQ %06x full (%u head, %u tail,"
 					" %d max, %d nreq)\n", qp->qpn,

-- 
MST