[PATCH v3 19/29] crypto/cnxk: fix inflight cnt calculation

[Anoob Joseph]

Inflight count calculation is updated to cover wrap around cases where
head can become smaller than tail.


Reported-by: Kiran Kumar K <kirankumark at marvell.com>
Signed-off-by: Anoob Joseph <anoobj at marvell.com>
---
 drivers/crypto/cnxk/cnxk_cryptodev_ops.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/cnxk/cnxk_cryptodev_ops.h b/drivers/crypto/cnxk/cnxk_cryptodev_ops.h
index ca363bb..0336ae1 100644
--- a/drivers/crypto/cnxk/cnxk_cryptodev_ops.h
+++ b/drivers/crypto/cnxk/cnxk_cryptodev_ops.h
@@ -156,7 +156,11 @@ pending_queue_retreat(uint64_t *index, const uint64_t mask, uint64_t nb_entry)
 static __rte_always_inline uint64_t
 pending_queue_infl_cnt(uint64_t head, uint64_t tail, const uint64_t mask)
 {
-	return (head - tail) & mask;
+	/*
+	 * Mask is nb_desc - 1. Add nb_desc to head and mask to account for
+	 * cases when tail > head, which happens during wrap around.
+	 */
+	return ((head + mask + 1) - tail) & mask;
 }
 
 static __rte_always_inline uint64_t
-- 
2.7.4