#ifndef _CRYPTO_LRW_H
  #define _CRYPTO_LRW_H
  
  #include <crypto/b128ops.h>
  
  struct scatterlist;
  struct gf128mul_64k;
  struct blkcipher_desc;
  
  #define LRW_BLOCK_SIZE 16
  
  struct lrw_table_ctx {
  	/* optimizes multiplying a random (non incrementing, as at the
  	 * start of a new sector) value with key2, we could also have
  	 * used 4k optimization tables or no optimization at all. In the
  	 * latter case we would have to store key2 here */
  	struct gf128mul_64k *table;
  	/* stores:
  	 *  key2*{ 0,0,...0,0,0,0,1 }, key2*{ 0,0,...0,0,0,1,1 },
  	 *  key2*{ 0,0,...0,0,1,1,1 }, key2*{ 0,0,...0,1,1,1,1 }
  	 *  key2*{ 0,0,...1,1,1,1,1 }, etc
  	 * needed for optimized multiplication of incrementing values
  	 * with key2 */
  	be128 mulinc[128];
  };
  
  int lrw_init_table(struct lrw_table_ctx *ctx, const u8 *tweak);
  void lrw_free_table(struct lrw_table_ctx *ctx);
  
  struct lrw_crypt_req {
  	be128 *tbuf;
  	unsigned int tbuflen;
  
  	struct lrw_table_ctx *table_ctx;
  	void *crypt_ctx;
  	void (*crypt_fn)(void *ctx, u8 *blks, unsigned int nbytes);
  };
  
  int lrw_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
  	      struct scatterlist *src, unsigned int nbytes,
  	      struct lrw_crypt_req *req);
  
  #endif  /* _CRYPTO_LRW_H */