IB/hfi1: Fix an assign/ordering issue with shared context IDs
The current algorithm for generating sub-context IDs is FILO. If the
contexts are not closed in that order, the uniqueness of the ID will be
compromised. I.e. logging the creation/deletion of context IDs with an
application that assigns and closes in a FIFO order reveals:
cache_id: assign: uctxt: 3 sub_ctxt: 0
cache_id: assign: uctxt: 3 sub_ctxt: 1
cache_id: assign: uctxt: 3 sub_ctxt: 2
cache_id: close: uctxt: 3 sub_ctxt: 0
cache_id: assign: uctxt: 3 sub_ctxt: 2 <<<
The sub_ctxt ID 2 is reused incorrectly.
Update the sub-context ID assign algorithm to use a bitmask of in_use
contexts. The new algorithm will allow the contexts to be closed in any
order, and will only re-use unused contexts.
Size subctxt and subctxt_cnt to match the user API size.
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@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/intr.c b/drivers/infiniband/hw/hfi1/intr.c
index 232014d..ba265d0 100644
--- a/drivers/infiniband/hw/hfi1/intr.c
+++ b/drivers/infiniband/hw/hfi1/intr.c
@@ -47,6 +47,7 @@
#include <linux/pci.h>
#include <linux/delay.h>
+#include <linux/bitmap.h>
#include "hfi.h"
#include "common.h"
@@ -189,7 +190,7 @@ void handle_user_interrupt(struct hfi1_ctxtdata *rcd)
unsigned long flags;
spin_lock_irqsave(&dd->uctxt_lock, flags);
- if (!rcd->cnt)
+ if (bitmap_empty(rcd->in_use_ctxts, HFI1_MAX_SHARED_CTXTS))
goto done;
if (test_and_clear_bit(HFI1_CTXT_WAITING_RCV, &rcd->event_flags)) {