[RFC PATCH 4/7] crypto: hash - Add ctx helpers with DMA alignment

["Herbert Xu" <herbert@gondor.apana.org.au>]

This patch adds helpers to access the ahash 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/hash.h |   28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/include/crypto/internal/hash.h b/include/crypto/internal/hash.h
index 25806141db591..f635a61fd1a0e 100644
--- a/include/crypto/internal/hash.h
+++ b/include/crypto/internal/hash.h
@@ -134,6 +134,11 @@ static inline void *crypto_ahash_ctx(struct crypto_ahash *tfm)
 	return crypto_tfm_ctx(crypto_ahash_tfm(tfm));
 }
 
+static inline void *crypto_ahash_ctx_dma(struct crypto_ahash *tfm)
+{
+	return crypto_tfm_ctx_dma(crypto_ahash_tfm(tfm));
+}
+
 static inline struct ahash_alg *__crypto_ahash_alg(struct crypto_alg *alg)
 {
 	return container_of(__crypto_hash_alg_common(alg), struct ahash_alg,
@@ -146,6 +151,15 @@ static inline void crypto_ahash_set_reqsize(struct crypto_ahash *tfm,
 	tfm->reqsize = reqsize;
 }
 
+static inline void crypto_ahash_set_reqsize_dma(struct crypto_ahash *ahash,
+						unsigned int reqsize)
+{
+#ifdef ARCH_DMA_MINALIGN
+	reqsize += ARCH_DMA_MINALIGN & ~(crypto_tfm_ctx_alignment() - 1);
+#endif
+	ahash->reqsize = reqsize;
+}
+
 static inline struct crypto_instance *ahash_crypto_instance(
 	struct ahash_instance *inst)
 {
@@ -169,6 +183,20 @@ static inline void *ahash_instance_ctx(struct ahash_instance *inst)
 	return crypto_instance_ctx(ahash_crypto_instance(inst));
 }
 
+static inline void *ahash_request_ctx_dma(struct ahash_request *req)
+{
+	unsigned int align = 1;
+
+#ifdef ARCH_DMA_MINALIGN
+	align = ARCH_DMA_MINALIGN;
+#endif
+
+	if (align <= crypto_tfm_ctx_alignment())
+		align = 1;
+
+	return PTR_ALIGN(ahash_request_ctx(req), align);
+}
+
 static inline void ahash_request_complete(struct ahash_request *req, int err)
 {
 	req->base.complete(&req->base, err);