RDMA/rxe: Remove save/rollback_state in rxe_requester

Now that req.task and comp.task are merged it is no longer necessary to
call save_state() before calling rxe_xmit_pkt() and rollback_state() if
rxe_xmit_pkt() fails. This was done originally to prevent races between
rxe_completer() and rxe_requester() which now cannot happen.

Link: https://lore.kernel.org/r/20240329145513.35381-8-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rxe/rxe_req.c
index 31a611ced3c5e38b7c53acdba37bc3327c14ec23..e20462c3040d184bd02d79eace6929862ff697c5 100644 (file)
--- a/drivers/infiniband/sw/rxe/rxe_req.c
+++ b/drivers/infiniband/sw/rxe/rxe_req.c
@@ -573,30 +573,6 @@ static void update_wqe_psn(struct rxe_qp *qp,
                qp->req.psn = (qp->req.psn + 1) & BTH_PSN_MASK;
 }
 
-static void save_state(struct rxe_send_wqe *wqe,
-                      struct rxe_qp *qp,
-                      struct rxe_send_wqe *rollback_wqe,
-                      u32 *rollback_psn)
-{
-       rollback_wqe->state = wqe->state;
-       rollback_wqe->first_psn = wqe->first_psn;
-       rollback_wqe->last_psn = wqe->last_psn;
-       rollback_wqe->dma = wqe->dma;
-       *rollback_psn = qp->req.psn;
-}
-
-static void rollback_state(struct rxe_send_wqe *wqe,
-                          struct rxe_qp *qp,
-                          struct rxe_send_wqe *rollback_wqe,
-                          u32 rollback_psn)
-{
-       wqe->state = rollback_wqe->state;
-       wqe->first_psn = rollback_wqe->first_psn;
-       wqe->last_psn = rollback_wqe->last_psn;
-       wqe->dma = rollback_wqe->dma;
-       qp->req.psn = rollback_psn;
-}
-
 static void update_state(struct rxe_qp *qp, struct rxe_pkt_info *pkt)
 {
        qp->req.opcode = pkt->opcode;
@@ -676,8 +652,6 @@ int rxe_requester(struct rxe_qp *qp)
        int opcode;
        int err;
        int ret;
-       struct rxe_send_wqe rollback_wqe;
-       u32 rollback_psn;
        struct rxe_queue *q = qp->sq.queue;
        struct rxe_ah *ah;
        struct rxe_av *av;
@@ -799,9 +773,6 @@ int rxe_requester(struct rxe_qp *qp)
        pkt.mask = rxe_opcode[opcode].mask;
        pkt.wqe = wqe;
 
-       /* save wqe state before we build and send packet */
-       save_state(wqe, qp, &rollback_wqe, &rollback_psn);
-
        av = rxe_get_av(&pkt, &ah);
        if (unlikely(!av)) {
                rxe_dbg_qp(qp, "Failed no address vector\n");
@@ -834,10 +805,6 @@ int rxe_requester(struct rxe_qp *qp)
        if (ah)
                rxe_put(ah);
 
-       /* update wqe state as though we had sent it */
-       update_wqe_state(qp, wqe, &pkt);
-       update_wqe_psn(qp, wqe, &pkt, payload);
-
        err = rxe_xmit_packet(qp, &pkt, skb);
        if (err) {
                if (err != -EAGAIN) {
@@ -845,11 +812,6 @@ int rxe_requester(struct rxe_qp *qp)
                        goto err;
                }
 
-               /* the packet was dropped so reset wqe to the state
-                * before we sent it so we can try to resend
-                */
-               rollback_state(wqe, qp, &rollback_wqe, rollback_psn);
-
                /* force a delay until the dropped packet is freed and
                 * the send queue is drained below the low water mark
                 */
@@ -859,6 +821,8 @@ int rxe_requester(struct rxe_qp *qp)
                goto exit;
        }
 
+       update_wqe_state(qp, wqe, &pkt);
+       update_wqe_psn(qp, wqe, &pkt, payload);
        update_state(qp, &pkt);
 
        /* A non-zero return value will cause rxe_do_task to