crypto: caam - add ahash_edesc_alloc() for descriptor allocation

Add a helper function to perform the descriptor allocation.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/caamhash.c

@@ -765,6 +765,25 @@ static void ahash_done_ctx_dst(struct device *jrdev, u32 *desc, u32 err,
 	req->base.complete(&req->base, err);
 }
 
+/*
+ * Allocate an enhanced descriptor, which contains the hardware descriptor
+ * and space for hardware scatter table containing sg_num entries.
+ */
+static struct ahash_edesc *ahash_edesc_alloc(struct caam_hash_ctx *ctx,
+					     int sg_num, gfp_t flags)
+{
+	struct ahash_edesc *edesc;
+	unsigned int sg_size = sg_num * sizeof(struct sec4_sg_entry);
+
+	edesc = kzalloc(sizeof(*edesc) + sg_size, GFP_DMA | flags);
+	if (!edesc) {
+		dev_err(ctx->jrdev, "could not allocate extended descriptor\n");
+		return NULL;
+	}
+
+	return edesc;
+}
+
 /* submit update job descriptor */
 static int ahash_update_ctx(struct ahash_request *req)
 {
@@ -818,11 +837,9 @@ static int ahash_update_ctx(struct ahash_request *req)
 		 * allocate space for base edesc and hw desc commands,
 		 * link tables
 		 */
-		edesc = kzalloc(sizeof(*edesc) + sec4_sg_bytes,
-				GFP_DMA | flags);
+		edesc = ahash_edesc_alloc(ctx, sec4_sg_src_index + mapped_nents,
+					  flags);
 		if (!edesc) {
-			dev_err(jrdev,
-				"could not allocate extended descriptor\n");
 			dma_unmap_sg(jrdev, req->src, src_nents, DMA_TO_DEVICE);
 			return -ENOMEM;
 		}
@@ -931,11 +948,9 @@ static int ahash_final_ctx(struct ahash_request *req)
 	sec4_sg_bytes = sec4_sg_src_index * sizeof(struct sec4_sg_entry);
 
 	/* allocate space for base edesc and hw desc commands, link tables */
-	edesc = kzalloc(sizeof(*edesc) + sec4_sg_bytes, GFP_DMA | flags);
-	if (!edesc) {
-		dev_err(jrdev, "could not allocate extended descriptor\n");
+	edesc = ahash_edesc_alloc(ctx, sec4_sg_src_index, flags);
+	if (!edesc)
 		return -ENOMEM;
-	}
 
 	sh_len = desc_len(sh_desc);
 	desc = edesc->hw_desc;
@@ -1034,9 +1049,9 @@ static int ahash_finup_ctx(struct ahash_request *req)
 			 sizeof(struct sec4_sg_entry);
 
 	/* allocate space for base edesc and hw desc commands, link tables */
-	edesc = kzalloc(sizeof(*edesc) + sec4_sg_bytes, GFP_DMA | flags);
+	edesc = ahash_edesc_alloc(ctx, sec4_sg_src_index + mapped_nents,
+				  flags);
 	if (!edesc) {
-		dev_err(jrdev, "could not allocate extended descriptor\n");
 		dma_unmap_sg(jrdev, req->src, src_nents, DMA_TO_DEVICE);
 		return -ENOMEM;
 	}
@@ -1136,9 +1151,9 @@ static int ahash_digest(struct ahash_request *req)
 		sec4_sg_bytes = 0;
 
 	/* allocate space for base edesc and hw desc commands, link tables */
-	edesc = kzalloc(sizeof(*edesc) + sec4_sg_bytes, GFP_DMA | flags);
+	edesc = ahash_edesc_alloc(ctx, mapped_nents > 1 ? mapped_nents : 0,
+				  flags);
 	if (!edesc) {
-		dev_err(jrdev, "could not allocate extended descriptor\n");
 		dma_unmap_sg(jrdev, req->src, src_nents, DMA_TO_DEVICE);
 		return -ENOMEM;
 	}
@@ -1212,13 +1227,10 @@ static int ahash_final_no_ctx(struct ahash_request *req)
 	int sh_len;
 
 	/* allocate space for base edesc and hw desc commands, link tables */
-	edesc = kzalloc(sizeof(*edesc), GFP_DMA | flags);
-	if (!edesc) {
-		dev_err(jrdev, "could not allocate extended descriptor\n");
+	edesc = ahash_edesc_alloc(ctx, 0, flags);
+	if (!edesc)
 		return -ENOMEM;
-	}
 
-	edesc->sec4_sg_bytes = 0;
 	sh_len = desc_len(sh_desc);
 	desc = edesc->hw_desc;
 	init_job_desc_shared(desc, ptr, sh_len, HDR_SHARE_DEFER | HDR_REVERSE);
@@ -1310,11 +1322,8 @@ static int ahash_update_no_ctx(struct ahash_request *req)
 		 * allocate space for base edesc and hw desc commands,
 		 * link tables
 		 */
-		edesc = kzalloc(sizeof(*edesc) + sec4_sg_bytes,
-				GFP_DMA | flags);
+		edesc = ahash_edesc_alloc(ctx, 1 + mapped_nents, flags);
 		if (!edesc) {
-			dev_err(jrdev,
-				"could not allocate extended descriptor\n");
 			dma_unmap_sg(jrdev, req->src, src_nents, DMA_TO_DEVICE);
 			return -ENOMEM;
 		}
@@ -1435,9 +1444,8 @@ static int ahash_finup_no_ctx(struct ahash_request *req)
 			 sizeof(struct sec4_sg_entry);
 
 	/* allocate space for base edesc and hw desc commands, link tables */
-	edesc = kzalloc(sizeof(*edesc) + sec4_sg_bytes, GFP_DMA | flags);
+	edesc = ahash_edesc_alloc(ctx, sec4_sg_src_index + mapped_nents, flags);
 	if (!edesc) {
-		dev_err(jrdev, "could not allocate extended descriptor\n");
 		dma_unmap_sg(jrdev, req->src, src_nents, DMA_TO_DEVICE);
 		return -ENOMEM;
 	}
@@ -1546,11 +1554,9 @@ static int ahash_update_first(struct ahash_request *req)
 		 * allocate space for base edesc and hw desc commands,
 		 * link tables
 		 */
-		edesc = kzalloc(sizeof(*edesc) + sec4_sg_bytes,
-				GFP_DMA | flags);
+		edesc = ahash_edesc_alloc(ctx, mapped_nents > 1 ?
+					  mapped_nents : 0, flags);
 		if (!edesc) {
-			dev_err(jrdev,
-				"could not allocate extended descriptor\n");
 			dma_unmap_sg(jrdev, req->src, src_nents, DMA_TO_DEVICE);
 			return -ENOMEM;
 		}