[PATCH v2 01/12] crypto: talitos - use dma_sync_single_for_cpu() before reading descriptor header

[Paul Louvel <paul.louvel@bootlin.com>]

In order to know if a descriptor has been processed by the device,
the driver polls the FIFO to see if DESC_HDR_DONE is set on a descriptor
header to confirm completion.
The current code does not make sure that the CPU gets up to date data
before reading the descriptor.

Fix this by calling dma_sync_single_for_cpu() before reading memory
written by the device.

Cc: stable@vger.kernel.org
Fixes: 58cdbc6d2263 ("crypto: talitos - fix hash on SEC1.")
Signed-off-by: Paul Louvel <paul.louvel@bootlin.com>
---
 drivers/crypto/talitos.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index bc61d0fe3514..303640e64717 100644
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -322,15 +322,25 @@ static int talitos_submit(struct device *dev, int ch, struct talitos_desc *desc,
 	return -EINPROGRESS;
 }
 
-static __be32 get_request_hdr(struct talitos_request *request, bool is_sec1)
+static __be32 get_request_hdr(struct device *dev, struct talitos_request *request, bool is_sec1)
 {
 	struct talitos_edesc *edesc;
+	dma_addr_t dma_desc;
+
+	if (!is_sec1) {
+		dma_sync_single_for_cpu(dev, request->dma_desc,
+					TALITOS_DESC_SIZE, DMA_BIDIRECTIONAL);
 
-	if (!is_sec1)
 		return request->desc->hdr;
+	}
 
 	if (!request->desc->next_desc)
-		return request->desc->hdr1;
+		dma_desc = request->dma_desc;
+	else
+		dma_desc = be32_to_cpu(request->desc->next_desc);
+
+	dma_sync_single_for_cpu(dev, dma_desc, TALITOS_DESC_SIZE,
+				DMA_BIDIRECTIONAL);
 
 	edesc = container_of(request->desc, struct talitos_edesc, desc);
 
@@ -358,7 +368,7 @@ static void flush_channel(struct device *dev, int ch, int error, int reset_ch)
 
 		/* descriptors with their done bits set don't get the error */
 		rmb();
-		hdr = get_request_hdr(request, is_sec1);
+		hdr = get_request_hdr(dev, request, is_sec1);
 
 		if ((hdr & DESC_HDR_DONE) == DESC_HDR_DONE)
 			status = 0;

-- 
2.53.0