crypto: aead - Add ctx helpers with DMA alignment

This patch adds helpers to access the aead 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/aead.h

@@ -39,6 +39,11 @@ static inline void *crypto_aead_ctx(struct crypto_aead *tfm)
 	return crypto_tfm_ctx(&tfm->base);
 }
 
+static inline void *crypto_aead_ctx_dma(struct crypto_aead *tfm)
+{
+	return crypto_tfm_ctx_dma(&tfm->base);
+}
+
 static inline struct crypto_instance *aead_crypto_instance(
 	struct aead_instance *inst)
 {
@@ -65,6 +70,16 @@ static inline void *aead_request_ctx(struct aead_request *req)
 	return req->__ctx;
 }
 
+static inline void *aead_request_ctx_dma(struct aead_request *req)
+{
+	unsigned int align = crypto_dma_align();
+
+	if (align <= crypto_tfm_ctx_alignment())
+		align = 1;
+
+	return PTR_ALIGN(aead_request_ctx(req), align);
+}
+
 static inline void aead_request_complete(struct aead_request *req, int err)
 {
 	req->base.complete(&req->base, err);
@@ -108,6 +123,13 @@ static inline void crypto_aead_set_reqsize(struct crypto_aead *aead,
 	aead->reqsize = reqsize;
 }
 
+static inline void crypto_aead_set_reqsize_dma(struct crypto_aead *aead,
+					       unsigned int reqsize)
+{
+	reqsize += crypto_dma_align() & ~(crypto_tfm_ctx_alignment() - 1);
+	aead->reqsize = reqsize;
+}
+
 static inline void aead_init_queue(struct aead_queue *queue,
 				   unsigned int max_qlen)
 {