crypto: akcipher - Add ctx helpers with DMA alignment

This patch adds helpers to access the akcipher context structure and
request context structure with an added alignment for DMA access.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/crypto/internal/akcipher.h

@@ -33,15 +33,37 @@ static inline void *akcipher_request_ctx(struct akcipher_request *req)
 	return req->__ctx;
 }
 
+static inline void *akcipher_request_ctx_dma(struct akcipher_request *req)
+{
+	unsigned int align = crypto_dma_align();
+
+	if (align <= crypto_tfm_ctx_alignment())
+		align = 1;
+
+	return PTR_ALIGN(akcipher_request_ctx(req), align);
+}
+
 static inline void akcipher_set_reqsize(struct crypto_akcipher *akcipher,
 					unsigned int reqsize)
 {
 	akcipher->reqsize = reqsize;
 }
 
+static inline void akcipher_set_reqsize_dma(struct crypto_akcipher *akcipher,
+					    unsigned int reqsize)
+{
+	reqsize += crypto_dma_align() & ~(crypto_tfm_ctx_alignment() - 1);
+	akcipher->reqsize = reqsize;
+}
+
 static inline void *akcipher_tfm_ctx(struct crypto_akcipher *tfm)
 {
-	return tfm->base.__crt_ctx;
+	return crypto_tfm_ctx(&tfm->base);
+}
+
+static inline void *akcipher_tfm_ctx_dma(struct crypto_akcipher *tfm)
+{
+	return crypto_tfm_ctx_dma(&tfm->base);
 }
 
 static inline void akcipher_request_complete(struct akcipher_request *req,