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path: root/drivers/infiniband/sw/rxe/rxe_req.c
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Diffstat (limited to 'drivers/infiniband/sw/rxe/rxe_req.c')
-rw-r--r--drivers/infiniband/sw/rxe/rxe_req.c57
1 files changed, 44 insertions, 13 deletions
diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rxe/rxe_req.c
index 33b2d9d77021..13a848a518e8 100644
--- a/drivers/infiniband/sw/rxe/rxe_req.c
+++ b/drivers/infiniband/sw/rxe/rxe_req.c
@@ -511,24 +511,21 @@ static int fill_packet(struct rxe_qp *qp, struct rxe_send_wqe *wqe,
}
static void update_wqe_state(struct rxe_qp *qp,
- struct rxe_send_wqe *wqe,
- struct rxe_pkt_info *pkt,
- enum wqe_state *prev_state)
+ struct rxe_send_wqe *wqe,
+ struct rxe_pkt_info *pkt)
{
- enum wqe_state prev_state_ = wqe->state;
-
if (pkt->mask & RXE_END_MASK) {
if (qp_type(qp) == IB_QPT_RC)
wqe->state = wqe_state_pending;
} else {
wqe->state = wqe_state_processing;
}
-
- *prev_state = prev_state_;
}
-static void update_state(struct rxe_qp *qp, struct rxe_send_wqe *wqe,
- struct rxe_pkt_info *pkt, int payload)
+static void update_wqe_psn(struct rxe_qp *qp,
+ struct rxe_send_wqe *wqe,
+ struct rxe_pkt_info *pkt,
+ int payload)
{
/* number of packets left to send including current one */
int num_pkt = (wqe->dma.resid + payload + qp->mtu - 1) / qp->mtu;
@@ -546,9 +543,34 @@ static void update_state(struct rxe_qp *qp, struct rxe_send_wqe *wqe,
qp->req.psn = (wqe->first_psn + num_pkt) & BTH_PSN_MASK;
else
qp->req.psn = (qp->req.psn + 1) & BTH_PSN_MASK;
+}
- qp->req.opcode = pkt->opcode;
+static void save_state(struct rxe_send_wqe *wqe,
+ struct rxe_qp *qp,
+ struct rxe_send_wqe *rollback_wqe,
+ struct rxe_qp *rollback_qp)
+{
+ rollback_wqe->state = wqe->state;
+ rollback_wqe->first_psn = wqe->first_psn;
+ rollback_wqe->last_psn = wqe->last_psn;
+ rollback_qp->req.psn = qp->req.psn;
+}
+static void rollback_state(struct rxe_send_wqe *wqe,
+ struct rxe_qp *qp,
+ struct rxe_send_wqe *rollback_wqe,
+ struct rxe_qp *rollback_qp)
+{
+ wqe->state = rollback_wqe->state;
+ wqe->first_psn = rollback_wqe->first_psn;
+ wqe->last_psn = rollback_wqe->last_psn;
+ qp->req.psn = rollback_qp->req.psn;
+}
+
+static void update_state(struct rxe_qp *qp, struct rxe_send_wqe *wqe,
+ struct rxe_pkt_info *pkt, int payload)
+{
+ qp->req.opcode = pkt->opcode;
if (pkt->mask & RXE_END_MASK)
qp->req.wqe_index = next_index(qp->sq.queue, qp->req.wqe_index);
@@ -571,7 +593,8 @@ int rxe_requester(void *arg)
int mtu;
int opcode;
int ret;
- enum wqe_state prev_state;
+ struct rxe_qp rollback_qp;
+ struct rxe_send_wqe rollback_wqe;
next_wqe:
if (unlikely(!qp->valid || qp->req.state == QP_STATE_ERROR))
@@ -688,13 +711,21 @@ next_wqe:
goto err;
}
- update_wqe_state(qp, wqe, &pkt, &prev_state);
+ /*
+ * To prevent a race on wqe access between requester and completer,
+ * wqe members state and psn need to be set before calling
+ * rxe_xmit_packet().
+ * Otherwise, completer might initiate an unjustified retry flow.
+ */
+ save_state(wqe, qp, &rollback_wqe, &rollback_qp);
+ update_wqe_state(qp, wqe, &pkt);
+ update_wqe_psn(qp, wqe, &pkt, payload);
ret = rxe_xmit_packet(to_rdev(qp->ibqp.device), qp, &pkt, skb);
if (ret) {
qp->need_req_skb = 1;
kfree_skb(skb);
- wqe->state = prev_state;
+ rollback_state(wqe, qp, &rollback_wqe, &rollback_qp);
if (ret == -EAGAIN) {
rxe_run_task(&qp->req.task, 1);