crypto: caam - update IV using HW support

Modify drivers to perform skcipher IV update using the crypto engine,
instead of performing the operation in SW.

Besides being more efficient, this also fixes IV update for CTR mode.

Output HW S/G table is appended with an entry pointing to the same
IV buffer used as input (which is now mapped BIDIRECTIONAL).

AS (Algorithm State) parameter of the OPERATION command is changed
from INIFINAL to INIT in descriptors used by ctr(aes), cbc(aes).
This is needed since in case FINAL bit is set, HW skips IV updating
in the Context Register for the last data block.

Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 39 insertions, 51 deletions

diff --git a/drivers/crypto/caam/caamalg_qi.c b/drivers/crypto/caam/caamalg_qi.c
index cec54344787c..32f0f8a72067 100644
--- a/drivers/crypto/caam/caamalg_qi.c
+++ b/drivers/crypto/caam/caamalg_qi.c
@@ -831,7 +831,8 @@ static struct caam_drv_ctx *get_drv_ctx(struct caam_ctx *ctx,
 static void caam_unmap(struct device *dev, struct scatterlist *src,
 		       struct scatterlist *dst, int src_nents,
 		       int dst_nents, dma_addr_t iv_dma, int ivsize,
-		       dma_addr_t qm_sg_dma, int qm_sg_bytes)
+		       enum dma_data_direction iv_dir, dma_addr_t qm_sg_dma,
+		       int qm_sg_bytes)
 {
 	if (dst != src) {
 		if (src_nents)
@@ -843,7 +844,7 @@ static void caam_unmap(struct device *dev, struct scatterlist *src,
 	}
 
 	if (iv_dma)
-		dma_unmap_single(dev, iv_dma, ivsize, DMA_TO_DEVICE);
+		dma_unmap_single(dev, iv_dma, ivsize, iv_dir);
 	if (qm_sg_bytes)
 		dma_unmap_single(dev, qm_sg_dma, qm_sg_bytes, DMA_TO_DEVICE);
 }
@@ -856,7 +857,8 @@ static void aead_unmap(struct device *dev,
 	int ivsize = crypto_aead_ivsize(aead);
 
 	caam_unmap(dev, req->src, req->dst, edesc->src_nents, edesc->dst_nents,
-		   edesc->iv_dma, ivsize, edesc->qm_sg_dma, edesc->qm_sg_bytes);
+		   edesc->iv_dma, ivsize, DMA_TO_DEVICE, edesc->qm_sg_dma,
+		   edesc->qm_sg_bytes);
 	dma_unmap_single(dev, edesc->assoclen_dma, 4, DMA_TO_DEVICE);
 }
 
@@ -867,7 +869,8 @@ static void skcipher_unmap(struct device *dev, struct skcipher_edesc *edesc,
 	int ivsize = crypto_skcipher_ivsize(skcipher);
 
 	caam_unmap(dev, req->src, req->dst, edesc->src_nents, edesc->dst_nents,
-		   edesc->iv_dma, ivsize, edesc->qm_sg_dma, edesc->qm_sg_bytes);
+		   edesc->iv_dma, ivsize, DMA_BIDIRECTIONAL, edesc->qm_sg_dma,
+		   edesc->qm_sg_bytes);
 }
 
 static void aead_done(struct caam_drv_req *drv_req, u32 status)
@@ -1036,7 +1039,7 @@ static struct aead_edesc *aead_edesc_alloc(struct aead_request *req,
 		dev_err(qidev, "No space for %d S/G entries and/or %dB IV\n",
 			qm_sg_ents, ivsize);
 		caam_unmap(qidev, req->src, req->dst, src_nents, dst_nents, 0,
-			   0, 0, 0);
+			   0, DMA_NONE, 0, 0);
 		qi_cache_free(edesc);
 		return ERR_PTR(-ENOMEM);
 	}
@@ -1051,7 +1054,7 @@ static struct aead_edesc *aead_edesc_alloc(struct aead_request *req,
 		if (dma_mapping_error(qidev, iv_dma)) {
 			dev_err(qidev, "unable to map IV\n");
 			caam_unmap(qidev, req->src, req->dst, src_nents,
-				   dst_nents, 0, 0, 0, 0);
+				   dst_nents, 0, 0, DMA_NONE, 0, 0);
 			qi_cache_free(edesc);
 			return ERR_PTR(-ENOMEM);
 		}
@@ -1070,7 +1073,7 @@ static struct aead_edesc *aead_edesc_alloc(struct aead_request *req,
 	if (dma_mapping_error(qidev, edesc->assoclen_dma)) {
 		dev_err(qidev, "unable to map assoclen\n");
 		caam_unmap(qidev, req->src, req->dst, src_nents, dst_nents,
-			   iv_dma, ivsize, 0, 0);
+			   iv_dma, ivsize, DMA_TO_DEVICE, 0, 0);
 		qi_cache_free(edesc);
 		return ERR_PTR(-ENOMEM);
 	}
@@ -1092,7 +1095,7 @@ static struct aead_edesc *aead_edesc_alloc(struct aead_request *req,
 		dev_err(qidev, "unable to map S/G table\n");
 		dma_unmap_single(qidev, edesc->assoclen_dma, 4, DMA_TO_DEVICE);
 		caam_unmap(qidev, req->src, req->dst, src_nents, dst_nents,
-			   iv_dma, ivsize, 0, 0);
+			   iv_dma, ivsize, DMA_TO_DEVICE, 0, 0);
 		qi_cache_free(edesc);
 		return ERR_PTR(-ENOMEM);
 	}
@@ -1206,11 +1209,10 @@ static void skcipher_done(struct caam_drv_req *drv_req, u32 status)
 
 	/*
 	 * The crypto API expects us to set the IV (req->iv) to the last
-	 * ciphertext block. This is used e.g. by the CTS mode.
+	 * ciphertext block (CBC mode) or last counter (CTR mode).
+	 * This is used e.g. by the CTS mode.
 	 */
-	if (edesc->drv_req.drv_ctx->op_type == ENCRYPT)
-		scatterwalk_map_and_copy(req->iv, req->dst, req->cryptlen -
-					 ivsize, ivsize, 0);
+	memcpy(req->iv, (u8 *)&edesc->sgt[0] + edesc->qm_sg_bytes, ivsize);
 
 	qi_cache_free(edesc);
 	skcipher_request_complete(req, status);
@@ -1279,22 +1281,17 @@ static struct skcipher_edesc *skcipher_edesc_alloc(struct skcipher_request *req,
 	dst_sg_idx = qm_sg_ents;
 
 	/*
+	 * Input, output HW S/G tables: [IV, src][dst, IV]
+	 * IV entries point to the same buffer
+	 * If src == dst, S/G entries are reused (S/G tables overlap)
+	 *
 	 * HW reads 4 S/G entries at a time; make sure the reads don't go beyond
-	 * the end of the table by allocating more S/G entries. Logic:
-	 * if (src != dst && output S/G)
-	 *      pad output S/G, if needed
-	 * else if (src == dst && S/G)
-	 *      overlapping S/Gs; pad one of them
-	 * else if (input S/G) ...
-	 *      pad input S/G, if needed
+	 * the end of the table by allocating more S/G entries.
 	 */
-	if (mapped_dst_nents > 1)
-		qm_sg_ents += pad_sg_nents(mapped_dst_nents);
-	else if ((req->src == req->dst) && (mapped_src_nents > 1))
-		qm_sg_ents = max(pad_sg_nents(qm_sg_ents),
-				 1 + pad_sg_nents(mapped_src_nents));
+	if (req->src != req->dst)
+		qm_sg_ents += pad_sg_nents(mapped_dst_nents + 1);
 	else
-		qm_sg_ents = pad_sg_nents(qm_sg_ents);
+		qm_sg_ents = 1 + pad_sg_nents(qm_sg_ents);
 
 	qm_sg_bytes = qm_sg_ents * sizeof(struct qm_sg_entry);
 	if (unlikely(offsetof(struct skcipher_edesc, sgt) + qm_sg_bytes +
@@ -1302,7 +1299,7 @@ static struct skcipher_edesc *skcipher_edesc_alloc(struct skcipher_request *req,
 		dev_err(qidev, "No space for %d S/G entries and/or %dB IV\n",
 			qm_sg_ents, ivsize);
 		caam_unmap(qidev, req->src, req->dst, src_nents, dst_nents, 0,
-			   0, 0, 0);
+			   0, DMA_NONE, 0, 0);
 		return ERR_PTR(-ENOMEM);
 	}
 
@@ -1311,7 +1308,7 @@ static struct skcipher_edesc *skcipher_edesc_alloc(struct skcipher_request *req,
 	if (unlikely(!edesc)) {
 		dev_err(qidev, "could not allocate extended descriptor\n");
 		caam_unmap(qidev, req->src, req->dst, src_nents, dst_nents, 0,
-			   0, 0, 0);
+			   0, DMA_NONE, 0, 0);
 		return ERR_PTR(-ENOMEM);
 	}
 
@@ -1320,11 +1317,11 @@ static struct skcipher_edesc *skcipher_edesc_alloc(struct skcipher_request *req,
 	iv = (u8 *)(sg_table + qm_sg_ents);
 	memcpy(iv, req->iv, ivsize);
 
-	iv_dma = dma_map_single(qidev, iv, ivsize, DMA_TO_DEVICE);
+	iv_dma = dma_map_single(qidev, iv, ivsize, DMA_BIDIRECTIONAL);
 	if (dma_mapping_error(qidev, iv_dma)) {
 		dev_err(qidev, "unable to map IV\n");
 		caam_unmap(qidev, req->src, req->dst, src_nents, dst_nents, 0,
-			   0, 0, 0);
+			   0, DMA_NONE, 0, 0);
 		qi_cache_free(edesc);
 		return ERR_PTR(-ENOMEM);
 	}
@@ -1338,18 +1335,20 @@ static struct skcipher_edesc *skcipher_edesc_alloc(struct skcipher_request *req,
 	edesc->drv_req.drv_ctx = drv_ctx;
 
 	dma_to_qm_sg_one(sg_table, iv_dma, ivsize, 0);
-	sg_to_qm_sg_last(req->src, req->cryptlen, sg_table + 1, 0);
+	sg_to_qm_sg(req->src, req->cryptlen, sg_table + 1, 0);
 
-	if (mapped_dst_nents > 1)
-		sg_to_qm_sg_last(req->dst, req->cryptlen, sg_table +
-				 dst_sg_idx, 0);
+	if (req->src != req->dst)
+		sg_to_qm_sg(req->dst, req->cryptlen, sg_table + dst_sg_idx, 0);
+
+	dma_to_qm_sg_one(sg_table + dst_sg_idx + mapped_dst_nents, iv_dma,
+			 ivsize, 0);
 
 	edesc->qm_sg_dma = dma_map_single(qidev, sg_table, edesc->qm_sg_bytes,
 					  DMA_TO_DEVICE);
 	if (dma_mapping_error(qidev, edesc->qm_sg_dma)) {
 		dev_err(qidev, "unable to map S/G table\n");
 		caam_unmap(qidev, req->src, req->dst, src_nents, dst_nents,
-			   iv_dma, ivsize, 0, 0);
+			   iv_dma, ivsize, DMA_BIDIRECTIONAL, 0, 0);
 		qi_cache_free(edesc);
 		return ERR_PTR(-ENOMEM);
 	}
@@ -1359,16 +1358,14 @@ static struct skcipher_edesc *skcipher_edesc_alloc(struct skcipher_request *req,
 	dma_to_qm_sg_one_last_ext(&fd_sgt[1], edesc->qm_sg_dma,
 				  ivsize + req->cryptlen, 0);
 
-	if (req->src == req->dst) {
+	if (req->src == req->dst)
 		dma_to_qm_sg_one_ext(&fd_sgt[0], edesc->qm_sg_dma +
-				     sizeof(*sg_table), req->cryptlen, 0);
-	} else if (mapped_dst_nents > 1) {
+				     sizeof(*sg_table), req->cryptlen + ivsize,
+				     0);
+	else
 		dma_to_qm_sg_one_ext(&fd_sgt[0], edesc->qm_sg_dma + dst_sg_idx *
-				     sizeof(*sg_table), req->cryptlen, 0);
-	} else {
-		dma_to_qm_sg_one(&fd_sgt[0], sg_dma_address(req->dst),
-				 req->cryptlen, 0);
-	}
+				     sizeof(*sg_table), req->cryptlen + ivsize,
+				     0);
 
 	return edesc;
 }
@@ -1378,7 +1375,6 @@ static inline int skcipher_crypt(struct skcipher_request *req, bool encrypt)
 	struct skcipher_edesc *edesc;
 	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 	struct caam_ctx *ctx = crypto_skcipher_ctx(skcipher);
-	int ivsize = crypto_skcipher_ivsize(skcipher);
 	int ret;
 
 	if (unlikely(caam_congested))
@@ -1389,14 +1385,6 @@ static inline int skcipher_crypt(struct skcipher_request *req, bool encrypt)
 	if (IS_ERR(edesc))
 		return PTR_ERR(edesc);
 
-	/*
-	 * The crypto API expects us to set the IV (req->iv) to the last
-	 * ciphertext block.
-	 */
-	if (!encrypt)
-		scatterwalk_map_and_copy(req->iv, req->src, req->cryptlen -
-					 ivsize, ivsize, 0);
-
 	ret = caam_qi_enqueue(ctx->qidev, &edesc->drv_req);
 	if (!ret) {
 		ret = -EINPROGRESS;