staging/rdma/hfi: fix CQ completion order issue

The current implementation of the sdma_wait variable
has a timing hole that can cause a completion Q entry
to be returned from a pio send prior to an older
sdma packets completion queue entry.

The sdma_wait variable used to be decremented prior to
calling the packet complete routine.  The hole is between decrement
and the verbs completion where send engine using pio could return
a out of order completion in that window.

This patch closes the hole by allowing an API option to
specify an sdma_drained callback.   The atomic dec
is positioned after the complete callback to avoid the
window as long as the pio path doesn't execute when
there is a non-zero sdma count.

Reviewed-by: Jubin John <jubin.john@intel.com>
Signed-off-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/staging/rdma/hfi1/sdma_txreq.h b/drivers/staging/rdma/hfi1/sdma_txreq.h
index 2effb35b9b91..bf7d777d756e 100644
--- a/drivers/staging/rdma/hfi1/sdma_txreq.h
+++ b/drivers/staging/rdma/hfi1/sdma_txreq.h
@@ -93,7 +93,7 @@ struct sdma_desc {
 #define SDMA_TXREQ_F_USE_AHG      0x0004
 
 struct sdma_txreq;
-typedef void (*callback_t)(struct sdma_txreq *, int, int);
+typedef void (*callback_t)(struct sdma_txreq *, int);
 
 struct iowait;
 struct sdma_txreq {