[RFC 19/32] crypto/caam_jr: use IO barrier before job ring doorbell

[Stephen Hemminger]

The barrier orders the input ring descriptor write in DMA memory
against the MMIO doorbell write. That is device ordering, not SMP
ordering: rte_io_wmb() is the correct barrier, and on arm64 the
inner shareable dmb the SMP barrier generated was not sufficient
to order against the device in the first place.

Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
 drivers/crypto/caam_jr/caam_jr.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/caam_jr/caam_jr.c b/drivers/crypto/caam_jr/caam_jr.c
index 1f97e72337..7a345c436e 100644
--- a/drivers/crypto/caam_jr/caam_jr.c
+++ b/drivers/crypto/caam_jr/caam_jr.c
@@ -1451,7 +1451,8 @@ caam_jr_enqueue_op(struct rte_crypto_op *op, struct caam_jr_qp *qp)
 	/* Set ptr in input ring to current descriptor	*/
 	sec_write_addr(&ring->input_ring[ring->pidx],
 			(phys_addr_t)caam_jr_vtop_ctx(ctx, ctx->jobdes.desc));
-	rte_smp_wmb();
+	/* Descriptor must be visible to the device before the doorbell */
+	rte_io_wmb();
 
 	/* Notify HW that a new job is enqueued */
 	hw_enqueue_desc_on_job_ring(ring);
-- 
2.53.0