crypto: skcipher - Add ctx helpers with DMA alignment

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

@@ -130,6 +130,13 @@ static inline void crypto_skcipher_set_reqsize(
 	skcipher->reqsize = reqsize;
 }
 
+static inline void crypto_skcipher_set_reqsize_dma(
+	struct crypto_skcipher *skcipher, unsigned int reqsize)
+{
+	reqsize += crypto_dma_align() & ~(crypto_tfm_ctx_alignment() - 1);
+	skcipher->reqsize = reqsize;
+}
+
 int crypto_register_skcipher(struct skcipher_alg *alg);
 void crypto_unregister_skcipher(struct skcipher_alg *alg);
 int crypto_register_skciphers(struct skcipher_alg *algs, int count);
@@ -159,11 +166,26 @@ static inline void *crypto_skcipher_ctx(struct crypto_skcipher *tfm)
 	return crypto_tfm_ctx(&tfm->base);
 }
 
+static inline void *crypto_skcipher_ctx_dma(struct crypto_skcipher *tfm)
+{
+	return crypto_tfm_ctx_dma(&tfm->base);
+}
+
 static inline void *skcipher_request_ctx(struct skcipher_request *req)
 {
 	return req->__ctx;
 }
 
+static inline void *skcipher_request_ctx_dma(struct skcipher_request *req)
+{
+	unsigned int align = crypto_dma_align();
+
+	if (align <= crypto_tfm_ctx_alignment())
+		align = 1;
+
+	return PTR_ALIGN(skcipher_request_ctx(req), align);
+}
+
 static inline u32 skcipher_request_flags(struct skcipher_request *req)
 {
 	return req->base.flags;