[RFC 20/32] crypto/octeontx: use IO barrier before doorbell

[Stephen Hemminger]

The doorbell is written with rte_write64_relaxed(), so the barrier
before it is what orders the queued instructions against the device.
That is device ordering, not SMP ordering: use rte_io_wmb().

Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
 drivers/crypto/octeontx/otx_cryptodev_hw_access.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/octeontx/otx_cryptodev_hw_access.h b/drivers/crypto/octeontx/otx_cryptodev_hw_access.h
index 3104e6d31e..096dcf8f87 100644
--- a/drivers/crypto/octeontx/otx_cryptodev_hw_access.h
+++ b/drivers/crypto/octeontx/otx_cryptodev_hw_access.h
@@ -203,8 +203,8 @@ static __rte_always_inline void
 otx_cpt_ring_dbell(struct cpt_instance *instance, uint16_t count)
 {
 	struct cpt_vf *cptvf = (struct cpt_vf *)instance;
-	/* Memory barrier to flush pending writes */
-	rte_smp_wmb();
+	/* Instructions must be visible to the device before the doorbell */
+	rte_io_wmb();
 	otx_cpt_write_vq_doorbell(cptvf, count);
 }
 
-- 
2.53.0