From: Kaike Wan <kaike.wan@xxxxxxxxx>
This locking mechanism is designed to provent vavious memory corruption
scenarios from occurring when requests are pipelined, especially when
RDMA READ/WRITE requests are interleaved with TID RDMA READ/WRITE
requests:
1. READ-AFTER-READ;
2. READ-AFTER-WRITE;
3. WRITE-AFTER-READ;
4. WRITE-AFTER-WRITE.
When memory corruption is likely, a request will be held back until
previous requests have been completed.
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Mitko Haralanov <mitko.haralanov@xxxxxxxxx>
Signed-off-by: Kaike Wan <kaike.wan@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
---
drivers/infiniband/hw/hfi1/rc.c | 22 ++++++++++
drivers/infiniband/hw/hfi1/tid_rdma.c | 76 +++++++++++++++++++++++++++++++++
drivers/infiniband/hw/hfi1/tid_rdma.h | 3 +
3 files changed, 101 insertions(+), 0 deletions(-)
diff --git a/drivers/infiniband/hw/hfi1/rc.c b/drivers/infiniband/hw/hfi1/rc.c
index 7bc635b..a65dc46 100644
--- a/drivers/infiniband/hw/hfi1/rc.c
+++ b/drivers/infiniband/hw/hfi1/rc.c
@@ -172,6 +172,12 @@ static int make_rc_ack(struct hfi1_ibdev *dev, struct rvt_qp *qp,
}
e = &qp->s_ack_queue[qp->s_tail_ack_queue];
+ /* Check for tid write fence */
+ if ((qpriv->s_flags & HFI1_R_TID_WAIT_INTERLCK) ||
+ hfi1_tid_rdma_ack_interlock(qp, e)) {
+ iowait_set_flag(&qpriv->s_iowait, IOWAIT_PENDING_IB);
+ goto bail;
+ }
if (e->opcode == OP(RDMA_READ_REQUEST)) {
/*
* If a RDMA read response is being resent and
@@ -573,6 +579,15 @@ int hfi1_make_rc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
len = wqe->length;
ss = &qp->s_sge;
bth2 = mask_psn(qp->s_psn);
+
+ /*
+ * Interlock between various IB requests and TID RDMA
+ * if necessary.
+ */
+ if ((priv->s_flags & HFI1_S_TID_WAIT_INTERLCK) ||
+ hfi1_tid_rdma_wqe_interlock(qp, wqe))
+ goto bail;
+
switch (wqe->wr.opcode) {
case IB_WR_SEND:
case IB_WR_SEND_WITH_IMM:
@@ -1556,6 +1571,7 @@ static void reset_psn(struct rvt_qp *qp, u32 psn)
qp->s_state = OP(SEND_LAST);
}
done:
+ priv->s_flags &= ~HFI1_S_TID_WAIT_INTERLCK;
qp->s_psn = psn;
/*
* Set RVT_S_WAIT_PSN as rc_complete() may start the timer
@@ -1828,6 +1844,8 @@ struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
struct rvt_swqe *wqe,
struct hfi1_ibport *ibp)
{
+ struct hfi1_qp_priv *priv = qp->priv;
+
lockdep_assert_held(&qp->s_lock);
/*
* Don't decrement refcount and don't generate a
@@ -1904,6 +1922,10 @@ struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
qp->s_draining = 0;
wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
}
+ if (priv->s_flags & HFI1_S_TID_WAIT_INTERLCK) {
+ priv->s_flags &= ~HFI1_S_TID_WAIT_INTERLCK;
+ hfi1_schedule_send(qp);
+ }
return wqe;
}
diff --git a/drivers/infiniband/hw/hfi1/tid_rdma.c b/drivers/infiniband/hw/hfi1/tid_rdma.c
index 0fd823c..932ef05 100644
--- a/drivers/infiniband/hw/hfi1/tid_rdma.c
+++ b/drivers/infiniband/hw/hfi1/tid_rdma.c
@@ -3895,6 +3895,82 @@ bool hfi1_handle_kdeth_eflags(struct hfi1_ctxtdata *rcd,
goto unlock;
}
+bool hfi1_tid_rdma_wqe_interlock(struct rvt_qp *qp, struct rvt_swqe *wqe)
+{
+ struct rvt_swqe *prev;
+ struct tid_rdma_request *req;
+ struct hfi1_qp_priv *priv = qp->priv;
+ u32 s_prev;
+
+ s_prev = (qp->s_cur == 0 ? qp->s_size : qp->s_cur) - 1;
+ prev = rvt_get_swqe_ptr(qp, s_prev);
+
+ switch (wqe->wr.opcode) {
+ case IB_WR_SEND:
+ case IB_WR_SEND_WITH_IMM:
+ case IB_WR_SEND_WITH_INV:
+ case IB_WR_ATOMIC_CMP_AND_SWP:
+ case IB_WR_ATOMIC_FETCH_AND_ADD:
+ case IB_WR_RDMA_WRITE:
+ switch (prev->wr.opcode) {
+ case IB_WR_TID_RDMA_WRITE:
+ req = wqe_to_tid_req(prev);
+ if (req->ack_seg != req->total_segs)
+ goto interlock;
+ default:
+ break;
+ }
+ case IB_WR_RDMA_READ:
+ if (prev->wr.opcode != IB_WR_TID_RDMA_WRITE)
+ break;
+ /* fall through */
+ case IB_WR_TID_RDMA_READ:
+ switch (prev->wr.opcode) {
+ case IB_WR_RDMA_READ:
+ if (qp->s_acked != qp->s_cur)
+ goto interlock;
+ break;
+ case IB_WR_TID_RDMA_WRITE:
+ req = wqe_to_tid_req(prev);
+ if (req->ack_seg != req->total_segs)
+ goto interlock;
+ default:
+ break;
+ }
+ default:
+ break;
+ }
+ return false;
+
+interlock:
+ priv->s_flags |= HFI1_S_TID_WAIT_INTERLCK;
+ return true;
+}
+
+bool hfi1_tid_rdma_ack_interlock(struct rvt_qp *qp, struct rvt_ack_entry *e)
+{
+ struct rvt_ack_entry *prev;
+ struct tid_rdma_request *req;
+ struct hfi1_ibdev *dev = to_idev(qp->ibqp.device);
+ struct hfi1_qp_priv *priv = qp->priv;
+ u32 s_prev;
+
+ s_prev = qp->s_tail_ack_queue == 0 ? rvt_size_atomic(&dev->rdi) :
+ (qp->s_tail_ack_queue - 1);
+ prev = &qp->s_ack_queue[s_prev];
+
+ if ((e->opcode == TID_OP(READ_REQ) ||
+ e->opcode == OP(RDMA_READ_REQUEST)) &&
+ prev->opcode == TID_OP(WRITE_REQ)) {
+ req = ack_to_tid_req(prev);
+ if (req->ack_seg != req->total_segs) {
+ priv->s_flags |= HFI1_R_TID_WAIT_INTERLCK;
+ return true;
+ }
+ }
+ return false;
+}
+
static void hfi1_tid_retry_timeout(struct timer_list *t)
{
struct hfi1_qp_priv *priv = from_timer(priv, t, s_tid_retry_timer);
diff --git a/drivers/infiniband/hw/hfi1/tid_rdma.h b/drivers/infiniband/hw/hfi1/tid_rdma.h
index 89384fb..9a0c353 100644
--- a/drivers/infiniband/hw/hfi1/tid_rdma.h
+++ b/drivers/infiniband/hw/hfi1/tid_rdma.h
@@ -291,6 +291,9 @@ bool hfi1_handle_kdeth_eflags(struct hfi1_ctxtdata *rcd,
struct hfi1_pportdata *ppd,
struct hfi1_packet *packet);
+bool hfi1_tid_rdma_wqe_interlock(struct rvt_qp *qp, struct rvt_swqe *wqe);
+bool hfi1_tid_rdma_ack_interlock(struct rvt_qp *qp, struct rvt_ack_entry *e);
+
void hfi1_del_tid_reap_timer(struct rvt_qp *qp);
void hfi1_add_tid_retry_timer(struct rvt_qp *qp);
--
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