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authorBernard Metzler <bmt@zurich.ibm.com>2022-01-30 20:08:15 +0300
committerJason Gunthorpe <jgg@nvidia.com>2022-02-01 16:54:28 +0300
commitb43a76f423aa304037603fd6165c4a534d2c09a7 (patch)
tree8d6325c883102540ef2a6a03bf224ff76eb41d05 /drivers/infiniband
parent4028bccb003cf67e46632dee7f97ddc5d7b6e685 (diff)
downloadlinux-b43a76f423aa304037603fd6165c4a534d2c09a7.tar.xz
RDMA/siw: Fix broken RDMA Read Fence/Resume logic.
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>
Diffstat (limited to 'drivers/infiniband')
-rw-r--r--drivers/infiniband/sw/siw/siw.h7
-rw-r--r--drivers/infiniband/sw/siw/siw_qp_rx.c20
2 files changed, 12 insertions, 15 deletions
diff --git a/drivers/infiniband/sw/siw/siw.h b/drivers/infiniband/sw/siw/siw.h
index 368959ae9a8c..df03d84c6868 100644
--- 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_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;
diff --git a/drivers/infiniband/sw/siw/siw_qp_rx.c b/drivers/infiniband/sw/siw/siw_qp_rx.c
index 60116f20653c..875ea6f1b04a 100644
--- 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_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);