Commit 2df41135 authored by Chandramohan Akula's avatar Chandramohan Akula Committed by Jason Gunthorpe
Browse files

RDMA/bnxt_re: Change the sequence of updating the CQ toggle value 

Currently the CQ toggle value in the shared page (read by the userlib) is
updated as part of the cqn_handler. There is a potential race of
application calling the CQ ARM doorbell immediately and using the old
toggle value.

Change the sequence of updating CQ toggle value to update in the
bnxt_qplib_service_nq function immediately after reading the toggle value
to be in sync with the HW updated value.

Fixes: e275919d ("RDMA/bnxt_re: Share a page to expose per CQ info with userspace")
Link: https://patch.msgid.link/r/1728373302-19530-9-git-send-email-selvin.xavier@broadcom.com


Signed-off-by: default avatarChandramohan Akula <chandramohan.akula@broadcom.com>
Reviewed-by: default avatarSelvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: default avatarSelvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent a5e099e0

drivers/infiniband/hw/bnxt_re/main.c

+1 −7
Original line number Diff line number Diff line
@@ -1274,15 +1274,9 @@ static int bnxt_re_cqn_handler(struct bnxt_qplib_nq *nq, 
{

	struct bnxt_re_cq *cq = container_of(handle, struct bnxt_re_cq,

					     qplib_cq);

	u32 *cq_ptr;



	if (cq->ib_cq.comp_handler) {

		if (cq->uctx_cq_page) {

			cq_ptr = (u32 *)cq->uctx_cq_page;

			*cq_ptr = cq->qplib_cq.toggle;

		}

	if (cq->ib_cq.comp_handler)

		(*cq->ib_cq.comp_handler)(&cq->ib_cq, cq->ib_cq.cq_context);

	}



	return 0;

}

drivers/infiniband/hw/bnxt_re/qplib_fp.c

+5 −0
Original line number Diff line number Diff line
@@ -327,6 +327,7 @@ static void bnxt_qplib_service_nq(struct tasklet_struct *t) 
		case NQ_BASE_TYPE_CQ_NOTIFICATION:

		{

			struct nq_cn *nqcne = (struct nq_cn *)nqe;

			struct bnxt_re_cq *cq_p;



			q_handle = le32_to_cpu(nqcne->cq_handle_low);

			q_handle |= (u64)le32_to_cpu(nqcne->cq_handle_high)
@@ -337,6 +338,10 @@ static void bnxt_qplib_service_nq(struct tasklet_struct *t) 
			cq->toggle = (le16_to_cpu(nqe->info10_type) &

					NQ_CN_TOGGLE_MASK) >> NQ_CN_TOGGLE_SFT;

			cq->dbinfo.toggle = cq->toggle;

			cq_p = container_of(cq, struct bnxt_re_cq, qplib_cq);

			if (cq_p->uctx_cq_page)

				*((u32 *)cq_p->uctx_cq_page) = cq->toggle;



			bnxt_qplib_armen_db(&cq->dbinfo,

					    DBC_DBC_TYPE_CQ_ARMENA);

			spin_lock_bh(&cq->compl_lock);