From ada13fea4dcc8419e0523614b108635d8f689000 Mon Sep 17 00:00:00 2001 From: Iuliana Prodan Date: Mon, 17 Feb 2020 03:05:10 +0200 Subject: [PATCH] LF-838: crypto: caam - increase the domain of write memory barrier to full system MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In caam_jr_enqueue, under heavy DDR load, smp_wmb() or dma_wmb() fail to make the input ring be updated before the CAAM starts reading it. So, CAAM will process, again, an old descriptor address and will put it in the output ring. This will make caam_jr_dequeue() to fail, since this old descriptor is not in the software ring. To fix this, use wmb() which works on the full system instead of inner/outer shareable domains. Signed-off-by: Iuliana Prodan Reviewed-by: Horia Geantă Signed-off-by: Leonard Crestez --- drivers/crypto/caam/jr.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/crypto/caam/jr.c +++ b/drivers/crypto/caam/jr.c @@ -434,8 +434,16 @@ int caam_jr_enqueue(struct device *dev, * 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. + * + * Under heavy DDR load, smp_wmb() or dma_wmb() fail to make the input + * ring be updated before the CAAM starts reading it. So, CAAM will + * process, again, an old descriptor address and will put it in the + * output ring. This will make caam_jr_dequeue() to fail, since this + * old descriptor is not in the software ring. + * To fix this, use wmb() which works on the full system instead of + * inner/outer shareable domains. */ - smp_wmb(); + wmb(); jrp->head = (head + 1) & (JOBR_DEPTH - 1);