RDMA/siw: Fix broken RDMA Read Fence/Resume logic.

commit b43a76f423 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: 8b6a361b8c ("rdma/siw: receive path")
Fixes: a531975279 ("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>
This commit is contained in:
Bernard Metzler 2022-01-30 18:08:15 +01:00 коммит произвёл Greg Kroah-Hartman
Родитель 7d9ad6f9f3
Коммит 035ea99c53
2 изменённых файлов: 12 добавлений и 15 удалений

Просмотреть файл

@ -644,14 +644,9 @@ static inline struct siw_sqe *orq_get_current(struct siw_qp *qp)
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;

Просмотреть файл

@ -1153,11 +1153,12 @@ static int siw_check_tx_fence(struct siw_qp *qp)
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_qp *qp)
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_qp *qp)
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);