Merge remote-tracking branches 'asoc/topic/nau8810', 'asoc/topic/of-bool', 'asoc...

[cascardo/linux.git] / drivers / infiniband / sw / rxe / rxe_req.c

diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rxe/rxe_req.c
index 33b2d9d..13a848a 100644 (file)
--- 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);