IB/hfi1: Inline common calculation

Calculating the offset to a context is done several times throughout
the code.  Create a common inlined function for doing this
calculation.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/hw/hfi1/user_exp_rcv.c b/drivers/infiniband/hw/hfi1/user_exp_rcv.c
index 6f6c14d..ff9ad69 100644
--- a/drivers/infiniband/hw/hfi1/user_exp_rcv.c
+++ b/drivers/infiniband/hw/hfi1/user_exp_rcv.c
@@ -542,8 +542,7 @@ int hfi1_user_exp_rcv_invalid(struct hfi1_filedata *fd,
 {
 	struct hfi1_ctxtdata *uctxt = fd->uctxt;
 	unsigned long *ev = uctxt->dd->events +
-		(((uctxt->ctxt - uctxt->dd->first_dyn_alloc_ctxt) *
-		  HFI1_MAX_SHARED_CTXTS) + fd->subctxt);
+		(uctxt_offset(uctxt) + fd->subctxt);
 	u32 *array;
 	int ret = 0;
 
@@ -942,8 +941,7 @@ static int tid_rb_invalidate(void *arg, struct mmu_rb_node *mnode)
 			 * process in question.
 			 */
 			ev = uctxt->dd->events +
-			  (((uctxt->ctxt - uctxt->dd->first_dyn_alloc_ctxt) *
-			    HFI1_MAX_SHARED_CTXTS) + fdata->subctxt);
+				(uctxt_offset(uctxt) + fdata->subctxt);
 			set_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
 		}
 		fdata->invalid_tid_idx++;