crypto: caam - Add cache coherency support

Freescale i.MX6 ARM platforms do not support hardware cache coherency.
This patch adds cache coherency support to the CAAM driver.

Signed-off-by: Victoria Milhoan <vicki.milhoan@freescale.com>
Tested-by: Horia Geantă <horia.geanta@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c
index b8b5d47acd7a..b7ec1ad38841 100644
--- a/drivers/crypto/caam/jr.c
+++ b/drivers/crypto/caam/jr.c
@@ -202,6 +202,13 @@ static void caam_jr_dequeue(unsigned long devarg)
 		userdesc = jrp->entinfo[sw_idx].desc_addr_virt;
 		userstatus = jrp->outring[hw_idx].jrstatus;
 
+		/*
+		 * Make sure all information from the job has been obtained
+		 * before telling CAAM that the job has been removed from the
+		 * output ring.
+		 */
+		mb();
+
 		/* set done */
 		wr_reg32(&jrp->rregs->outring_rmvd, 1);
 
@@ -351,12 +358,23 @@ int caam_jr_enqueue(struct device *dev, u32 *desc,
 
 	jrp->inpring[jrp->inp_ring_write_index] = desc_dma;
 
+	/*
+	 * Guarantee that the descriptor's DMA address has been written to
+	 * the next slot in the ring before the write index is updated, since
+	 * other cores may update this index independently.
+	 */
 	smp_wmb();
 
 	jrp->inp_ring_write_index = (jrp->inp_ring_write_index + 1) &
 				    (JOBR_DEPTH - 1);
 	jrp->head = (head + 1) & (JOBR_DEPTH - 1);
 
+	/*
+	 * Ensure that all job information has been written before
+	 * notifying CAAM that a new job was added to the input ring.
+	 */
+	wmb();
+
 	wr_reg32(&jrp->rregs->inpring_jobadd, 1);
 
 	spin_unlock_bh(&jrp->inplock);