crypto: api - Add crypto_tfm_ctx_dma

This patch adds the helpers crypto_tfm_ctx_aligned and
crypto_tfm_ctx_dma.  The first aligns the tfm context to the
value cra_alignmask.  The second sets the alignment according
to dma_cache_get_alignment();

This patch also moves crypto_tfm_ctx into algapi.h.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/crypto/algapi.h

@@ -7,6 +7,7 @@
 #ifndef _CRYPTO_ALGAPI_H
 #define _CRYPTO_ALGAPI_H
 
+#include <asm/cache.h>
 #include <linux/align.h>
 #include <linux/crypto.h>
 #include <linux/kconfig.h>
@@ -25,6 +26,14 @@
 #define MAX_CIPHER_BLOCKSIZE		16
 #define MAX_CIPHER_ALIGNMASK		15
 
+#ifdef ARCH_DMA_MINALIGN
+#define CRYPTO_DMA_ALIGN ARCH_DMA_MINALIGN
+#else
+#define CRYPTO_DMA_ALIGN CRYPTO_MINALIGN
+#endif
+
+#define CRYPTO_DMA_PADDING ((CRYPTO_DMA_ALIGN - 1) & ~(CRYPTO_MINALIGN - 1))
+
 struct crypto_aead;
 struct crypto_instance;
 struct module;
@@ -189,10 +198,38 @@ static inline void crypto_xor_cpy(u8 *dst, const u8 *src1, const u8 *src2,
 	}
 }
 
+static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)
+{
+	return tfm->__crt_ctx;
+}
+
+static inline void *crypto_tfm_ctx_align(struct crypto_tfm *tfm,
+					 unsigned int align)
+{
+	if (align <= crypto_tfm_ctx_alignment())
+		align = 1;
+
+	return PTR_ALIGN(crypto_tfm_ctx(tfm), align);
+}
+
 static inline void *crypto_tfm_ctx_aligned(struct crypto_tfm *tfm)
 {
-	return PTR_ALIGN(crypto_tfm_ctx(tfm),
-			 crypto_tfm_alg_alignmask(tfm) + 1);
+	return crypto_tfm_ctx_align(tfm, crypto_tfm_alg_alignmask(tfm) + 1);
+}
+
+static inline unsigned int crypto_dma_align(void)
+{
+	return CRYPTO_DMA_ALIGN;
+}
+
+static inline unsigned int crypto_dma_padding(void)
+{
+	return (crypto_dma_align() - 1) & ~(crypto_tfm_ctx_alignment() - 1);
+}
+
+static inline void *crypto_tfm_ctx_dma(struct crypto_tfm *tfm)
+{
+	return crypto_tfm_ctx_align(tfm, crypto_dma_align());
 }
 
 static inline struct crypto_instance *crypto_tfm_alg_instance(

include/linux/crypto.h

@@ -714,11 +714,6 @@ static inline void crypto_tfm_clear_flags(struct crypto_tfm *tfm, u32 flags)
 	tfm->crt_flags &= ~flags;
 }
 
-static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)
-{
-	return tfm->__crt_ctx;
-}
-
 static inline unsigned int crypto_tfm_ctx_alignment(void)
 {
 	struct crypto_tfm *tfm;