[PATCH 04/12] crypto: caam - fix HW S/G in ablkcipher_giv_edesc_alloc()

[Horia Geantă]

HW S/G generation does not work properly when the following conditions
are met:
-src == dst
-src/dst is S/G
-IV is right before (contiguous with) the first src/dst S/G entry
since "iv_contig" is set to true (iv_contig is a misnomer here and
it actually refers to the whole output being contiguous)

Fix this by setting dst S/G nents equal to src S/G nents, instead of
leaving it set to init value (0).

Signed-off-by: Horia Geantă <horia.gea...@nxp.com>
---
 drivers/crypto/caam/caamalg.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c
index 662fe94cb2f8..05d4690351b9 100644
--- a/drivers/crypto/caam/caamalg.c
+++ b/drivers/crypto/caam/caamalg.c
@@ -1798,7 +1798,7 @@ static struct ablkcipher_edesc 
*ablkcipher_giv_edesc_alloc(
        gfp_t flags = (req->base.flags & (CRYPTO_TFM_REQ_MAY_BACKLOG |
                                          CRYPTO_TFM_REQ_MAY_SLEEP)) ?
                       GFP_KERNEL : GFP_ATOMIC;
-       int src_nents, dst_nents = 0, sec4_sg_bytes;
+       int src_nents, dst_nents, sec4_sg_bytes;
        struct ablkcipher_edesc *edesc;
        dma_addr_t iv_dma = 0;
        bool iv_contig = false;
@@ -1808,9 +1808,6 @@ static struct ablkcipher_edesc 
*ablkcipher_giv_edesc_alloc(
 
        src_nents = sg_count(req->src, req->nbytes);
 
-       if (unlikely(req->dst != req->src))
-               dst_nents = sg_count(req->dst, req->nbytes);
-
        if (likely(req->src == req->dst)) {
                sgc = dma_map_sg(jrdev, req->src, src_nents ? : 1,
                                 DMA_BIDIRECTIONAL);
@@ -1818,6 +1815,8 @@ static struct ablkcipher_edesc 
*ablkcipher_giv_edesc_alloc(
                        dev_err(jrdev, "unable to map source\n");
                        return ERR_PTR(-ENOMEM);
                }
+
+               dst_nents = src_nents;
        } else {
                sgc = dma_map_sg(jrdev, req->src, src_nents ? : 1,
                                 DMA_TO_DEVICE);
@@ -1826,6 +1825,7 @@ static struct ablkcipher_edesc 
*ablkcipher_giv_edesc_alloc(
                        return ERR_PTR(-ENOMEM);
                }
 
+               dst_nents = sg_count(req->dst, req->nbytes);
                sgc = dma_map_sg(jrdev, req->dst, dst_nents ? : 1,
                                 DMA_FROM_DEVICE);
                if (unlikely(!sgc)) {
-- 
2.4.4