IB/mthca: Avoid alignment traps when writing doorbells
Architectures such as ia64 see alignment traps when doing a 64-bit
read from __be32 doorbell[2] arrays to do doorbell writes in
mthca_write64(). Fix this by just passing the two halves of the
doorbell value into mthca_write64(). This actually improves the
generated code by allowing the compiler to see what's going on better.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/mthca/mthca_srq.c b/drivers/infiniband/hw/mthca/mthca_srq.c
index 3f58c11..553d681 100644
--- a/drivers/infiniband/hw/mthca/mthca_srq.c
+++ b/drivers/infiniband/hw/mthca/mthca_srq.c
@@ -491,7 +491,6 @@
{
struct mthca_dev *dev = to_mdev(ibsrq->device);
struct mthca_srq *srq = to_msrq(ibsrq);
- __be32 doorbell[2];
unsigned long flags;
int err = 0;
int first_ind;
@@ -563,16 +562,13 @@
if (unlikely(nreq == MTHCA_TAVOR_MAX_WQES_PER_RECV_DB)) {
nreq = 0;
- doorbell[0] = cpu_to_be32(first_ind << srq->wqe_shift);
- doorbell[1] = cpu_to_be32(srq->srqn << 8);
-
/*
* Make sure that descriptors are written
* before doorbell is rung.
*/
wmb();
- mthca_write64(doorbell,
+ mthca_write64(first_ind << srq->wqe_shift, srq->srqn << 8,
dev->kar + MTHCA_RECEIVE_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
@@ -581,16 +577,13 @@
}
if (likely(nreq)) {
- doorbell[0] = cpu_to_be32(first_ind << srq->wqe_shift);
- doorbell[1] = cpu_to_be32((srq->srqn << 8) | nreq);
-
/*
* Make sure that descriptors are written before
* doorbell is rung.
*/
wmb();
- mthca_write64(doorbell,
+ mthca_write64(first_ind << srq->wqe_shift, (srq->srqn << 8) | nreq,
dev->kar + MTHCA_RECEIVE_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
}
