[PATCH 17/19] crypto: sun8i-ce: use sg_nents_for_len

[Corentin Labbe]

When testing with some large SG list, the sun8i-ce drivers always
fallback even if it can handle it.
So use sg_nents_for_len() which permits to see less SGs than needed.

Signed-off-by: Corentin Labbe <clabbe at baylibre.com>
---
 .../allwinner/sun8i-ce/sun8i-ce-cipher.c      | 23 ++++++++-----------
 .../crypto/allwinner/sun8i-ce/sun8i-ce-hash.c | 10 ++++----
 2 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
index 0b1ce58bdeb9..35ab71d3a82d 100644
--- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
@@ -26,7 +26,8 @@ static int sun8i_ce_cipher_need_fallback(struct skcipher_request *areq)
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct scatterlist *sg;
 
-	if (sg_nents(areq->src) > MAX_SG || sg_nents(areq->dst) > MAX_SG)
+	if (sg_nents_for_len(areq->src, areq->cryptlen) > MAX_SG ||
+	    sg_nents_for_len(areq->dst, areq->cryptlen) > MAX_SG)
 		return true;
 
 	if (areq->cryptlen < crypto_skcipher_ivsize(tfm))
@@ -94,6 +95,8 @@ static int sun8i_ce_cipher_prepare(struct crypto_engine *engine, void *async_req
 	int nr_sgs = 0;
 	int nr_sgd = 0;
 	int err = 0;
+	int ns = sg_nents_for_len(areq->src, areq->cryptlen);
+	int nd = sg_nents_for_len(areq->dst, areq->cryptlen);
 
 	algt = container_of(alg, struct sun8i_ce_alg_template, alg.skcipher);
 
@@ -169,8 +172,7 @@ static int sun8i_ce_cipher_prepare(struct crypto_engine *engine, void *async_req
 	}
 
 	if (areq->src == areq->dst) {
-		nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src),
-				    DMA_BIDIRECTIONAL);
+		nr_sgs = dma_map_sg(ce->dev, areq->src, ns, DMA_BIDIRECTIONAL);
 		if (nr_sgs <= 0 || nr_sgs > MAX_SG) {
 			dev_err(ce->dev, "Invalid sg number %d\n", nr_sgs);
 			err = -EINVAL;
@@ -178,15 +180,13 @@ static int sun8i_ce_cipher_prepare(struct crypto_engine *engine, void *async_req
 		}
 		nr_sgd = nr_sgs;
 	} else {
-		nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src),
-				    DMA_TO_DEVICE);
+		nr_sgs = dma_map_sg(ce->dev, areq->src, ns, DMA_TO_DEVICE);
 		if (nr_sgs <= 0 || nr_sgs > MAX_SG) {
 			dev_err(ce->dev, "Invalid sg number %d\n", nr_sgs);
 			err = -EINVAL;
 			goto theend_iv;
 		}
-		nr_sgd = dma_map_sg(ce->dev, areq->dst, sg_nents(areq->dst),
-				    DMA_FROM_DEVICE);
+		nr_sgd = dma_map_sg(ce->dev, areq->dst, nd, DMA_FROM_DEVICE);
 		if (nr_sgd <= 0 || nr_sgd > MAX_SG) {
 			dev_err(ce->dev, "Invalid sg number %d\n", nr_sgd);
 			err = -EINVAL;
@@ -231,14 +231,11 @@ static int sun8i_ce_cipher_prepare(struct crypto_engine *engine, void *async_req
 
 theend_sgs:
 	if (areq->src == areq->dst) {
-		dma_unmap_sg(ce->dev, areq->src, sg_nents(areq->src),
-			     DMA_BIDIRECTIONAL);
+		dma_unmap_sg(ce->dev, areq->src, ns, DMA_BIDIRECTIONAL);
 	} else {
 		if (nr_sgs > 0)
-			dma_unmap_sg(ce->dev, areq->src, sg_nents(areq->src),
-				     DMA_TO_DEVICE);
-		dma_unmap_sg(ce->dev, areq->dst, sg_nents(areq->dst),
-			     DMA_FROM_DEVICE);
+			dma_unmap_sg(ce->dev, areq->src, ns, DMA_TO_DEVICE);
+		dma_unmap_sg(ce->dev, areq->dst, nd, DMA_FROM_DEVICE);
 	}
 
 theend_iv:
diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-hash.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-hash.c
index 820651f0387f..17f6885dbe35 100644
--- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-hash.c
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-hash.c
@@ -204,7 +204,7 @@ static bool sun8i_ce_hash_need_fallback(struct ahash_request *areq)
 	if (areq->nbytes == 0)
 		return true;
 	/* we need to reserve one SG for padding one */
-	if (sg_nents(areq->src) > MAX_SG - 1)
+	if (sg_nents_for_len(areq->src, areq->nbytes) > MAX_SG - 1)
 		return true;
 	sg = areq->src;
 	while (sg) {
@@ -229,7 +229,7 @@ int sun8i_ce_hash_digest(struct ahash_request *areq)
 	if (sun8i_ce_hash_need_fallback(areq))
 		return sun8i_ce_hash_digest_fb(areq);
 
-	nr_sgs = sg_nents(areq->src);
+	nr_sgs = sg_nents_for_len(areq->src, areq->nbytes);
 	if (nr_sgs > MAX_SG - 1)
 		return sun8i_ce_hash_digest_fb(areq);
 
@@ -328,6 +328,7 @@ int sun8i_ce_hash_run(struct crypto_engine *engine, void *breq)
 	u64 bs;
 	int digestsize;
 	dma_addr_t addr_res, addr_pad;
+	int ns = sg_nents_for_len(areq->src, areq->nbytes);
 
 	algt = container_of(alg, struct sun8i_ce_alg_template, alg.hash);
 	ce = algt->ce;
@@ -372,7 +373,7 @@ int sun8i_ce_hash_run(struct crypto_engine *engine, void *breq)
 	cet->t_sym_ctl = 0;
 	cet->t_asym_ctl = 0;
 
-	nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src), DMA_TO_DEVICE);
+	nr_sgs = dma_map_sg(ce->dev, areq->src, ns, DMA_TO_DEVICE);
 	if (nr_sgs <= 0 || nr_sgs > MAX_SG) {
 		dev_err(ce->dev, "Invalid sg number %d\n", nr_sgs);
 		err = -EINVAL;
@@ -441,8 +442,7 @@ int sun8i_ce_hash_run(struct crypto_engine *engine, void *breq)
 	err = sun8i_ce_run_task(ce, flow, crypto_tfm_alg_name(areq->base.tfm));
 
 	dma_unmap_single(ce->dev, addr_pad, j * 4, DMA_TO_DEVICE);
-	dma_unmap_sg(ce->dev, areq->src, sg_nents(areq->src),
-		     DMA_TO_DEVICE);
+	dma_unmap_sg(ce->dev, areq->src, ns, DMA_TO_DEVICE);
 	dma_unmap_single(ce->dev, addr_res, digestsize, DMA_FROM_DEVICE);
 
 
-- 
2.34.1