6.11-stable review patch. If anyone has any objections, please let me know.
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From: Chandramohan Akula chandramohan.akula@broadcom.com
[ Upstream commit 2df411353dacc4b0c911f8c4944f8ffab955391c ]
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: e275919d9669 ("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@b... Signed-off-by: Chandramohan Akula chandramohan.akula@broadcom.com Reviewed-by: Selvin Xavier selvin.xavier@broadcom.com Signed-off-by: Selvin Xavier selvin.xavier@broadcom.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/hw/bnxt_re/main.c | 8 +------- drivers/infiniband/hw/bnxt_re/qplib_fp.c | 5 +++++ 2 files changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/infiniband/hw/bnxt_re/main.c b/drivers/infiniband/hw/bnxt_re/main.c index c905a51aabfba..9b7093eb439c6 100644 --- a/drivers/infiniband/hw/bnxt_re/main.c +++ b/drivers/infiniband/hw/bnxt_re/main.c @@ -1257,15 +1257,9 @@ 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; } diff --git a/drivers/infiniband/hw/bnxt_re/qplib_fp.c b/drivers/infiniband/hw/bnxt_re/qplib_fp.c index 19bb45329a19b..03d517be9c52e 100644 --- a/drivers/infiniband/hw/bnxt_re/qplib_fp.c +++ b/drivers/infiniband/hw/bnxt_re/qplib_fp.c @@ -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);