From: Bernard Metzler bmt@zurich.ibm.com
commit b43a76f423aa304037603fd6165c4a534d2c09a7 upstream.
Code unconditionally resumed fenced SQ processing after next RDMA Read completion, even if other RDMA Read responses are still outstanding, or ORQ is full. Also adds comments for better readability of fence processing, and removes orq_get_tail() helper, which is not needed anymore.
Fixes: 8b6a361b8c48 ("rdma/siw: receive path") Fixes: a531975279f3 ("rdma/siw: main include file") Link: https://lore.kernel.org/r/20220130170815.1940-1-bmt@zurich.ibm.com Reported-by: Jared Holzman jared.holzman@excelero.com Signed-off-by: Bernard Metzler bmt@zurich.ibm.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/infiniband/sw/siw/siw.h | 7 +------ drivers/infiniband/sw/siw/siw_qp_rx.c | 20 +++++++++++--------- 2 files changed, 12 insertions(+), 15 deletions(-)
--- a/drivers/infiniband/sw/siw/siw.h +++ b/drivers/infiniband/sw/siw/siw.h @@ -644,14 +644,9 @@ static inline struct siw_sqe *orq_get_cu return &qp->orq[qp->orq_get % qp->attrs.orq_size]; }
-static inline struct siw_sqe *orq_get_tail(struct siw_qp *qp) -{ - return &qp->orq[qp->orq_put % qp->attrs.orq_size]; -} - static inline struct siw_sqe *orq_get_free(struct siw_qp *qp) { - struct siw_sqe *orq_e = orq_get_tail(qp); + struct siw_sqe *orq_e = &qp->orq[qp->orq_put % qp->attrs.orq_size];
if (READ_ONCE(orq_e->flags) == 0) return orq_e; --- a/drivers/infiniband/sw/siw/siw_qp_rx.c +++ b/drivers/infiniband/sw/siw/siw_qp_rx.c @@ -1153,11 +1153,12 @@ static int siw_check_tx_fence(struct siw
spin_lock_irqsave(&qp->orq_lock, flags);
- rreq = orq_get_current(qp); - /* free current orq entry */ + rreq = orq_get_current(qp); WRITE_ONCE(rreq->flags, 0);
+ qp->orq_get++; + if (qp->tx_ctx.orq_fence) { if (unlikely(tx_waiting->wr_status != SIW_WR_QUEUED)) { pr_warn("siw: [QP %u]: fence resume: bad status %d\n", @@ -1165,10 +1166,12 @@ static int siw_check_tx_fence(struct siw rv = -EPROTO; goto out; } - /* resume SQ processing */ + /* resume SQ processing, if possible */ if (tx_waiting->sqe.opcode == SIW_OP_READ || tx_waiting->sqe.opcode == SIW_OP_READ_LOCAL_INV) { - rreq = orq_get_tail(qp); + + /* SQ processing was stopped because of a full ORQ */ + rreq = orq_get_free(qp); if (unlikely(!rreq)) { pr_warn("siw: [QP %u]: no ORQE\n", qp_id(qp)); rv = -EPROTO; @@ -1181,15 +1184,14 @@ static int siw_check_tx_fence(struct siw resume_tx = 1;
} else if (siw_orq_empty(qp)) { + /* + * SQ processing was stopped by fenced work request. + * Resume since all previous Read's are now completed. + */ qp->tx_ctx.orq_fence = 0; resume_tx = 1; - } else { - pr_warn("siw: [QP %u]: fence resume: orq idx: %d:%d\n", - qp_id(qp), qp->orq_get, qp->orq_put); - rv = -EPROTO; } } - qp->orq_get++; out: spin_unlock_irqrestore(&qp->orq_lock, flags);