#ifndef _CRYPTO_XTS_H
  #define _CRYPTO_XTS_H
  
  #include <crypto/b128ops.h>
  
  struct scatterlist;
  struct blkcipher_desc;
  
  #define XTS_BLOCK_SIZE 16
  
  struct xts_crypt_req {
  	be128 *tbuf;
  	unsigned int tbuflen;
  
  	void *tweak_ctx;
  	void (*tweak_fn)(void *ctx, u8* dst, const u8* src);
  	void *crypt_ctx;
  	void (*crypt_fn)(void *ctx, u8 *blks, unsigned int nbytes);
  };
  
  #define XTS_TWEAK_CAST(x) ((void (*)(void *, u8*, const u8*))(x))
  
  int xts_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
  	      struct scatterlist *src, unsigned int nbytes,
  	      struct xts_crypt_req *req);
  
  #endif  /* _CRYPTO_XTS_H */