4185 New hash algorithm support

*** 20,35 ****
   */
  /*
   * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  #include <sys/zfs_context.h>
  #include <sys/zio.h>
  #include <sys/sha2.h>
  
  void
! zio_checksum_SHA256(const void *buf, uint64_t size, zio_cksum_t *zcp)
  {
          SHA2_CTX ctx;
          zio_cksum_t tmp;
  
          SHA2Init(SHA256, &ctx);
--- 20,40 ----
   */
  /*
   * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
+ /*
+  * Copyright 2013 Saso Kiselkov. All rights reserved.
+  */
  #include <sys/zfs_context.h>
  #include <sys/zio.h>
  #include <sys/sha2.h>
  
+ /*ARGSUSED*/
  void
! zio_checksum_SHA256(const void *buf, uint64_t size,
!     const zio_cksum_salt_t *salt, const void *ctx_template, zio_cksum_t *zcp)
  {
          SHA2_CTX ctx;
          zio_cksum_t tmp;
  
          SHA2Init(SHA256, &ctx);
*** 45,50 ****
--- 50,81 ----
           */
          zcp->zc_word[0] = BE_64(tmp.zc_word[0]);
          zcp->zc_word[1] = BE_64(tmp.zc_word[1]);
          zcp->zc_word[2] = BE_64(tmp.zc_word[2]);
          zcp->zc_word[3] = BE_64(tmp.zc_word[3]);
+ }
+ 
+ /*ARGSUSED*/
+ void
+ zio_checksum_SHA512_native(const void *buf, uint64_t size,
+     const zio_cksum_salt_t *salt, const void *ctx_template, zio_cksum_t *zcp)
+ {
+         SHA2_CTX        ctx;
+ 
+         SHA2Init(SHA512_256, &ctx);
+         SHA2Update(&ctx, buf, size);
+         SHA2Final(zcp, &ctx);
+ }
+ 
+ /*ARGSUSED*/
+ void
+ zio_checksum_SHA512_byteswap(const void *buf, uint64_t size,
+     const zio_cksum_salt_t *salt, const void *ctx_template, zio_cksum_t *zcp)
+ {
+         zio_cksum_t     tmp;
+ 
+         zio_checksum_SHA512_native(buf, size, salt, ctx_template, &tmp);
+         zcp->zc_word[0] = BSWAP_64(tmp.zc_word[0]);
+         zcp->zc_word[1] = BSWAP_64(tmp.zc_word[1]);
+         zcp->zc_word[2] = BSWAP_64(tmp.zc_word[2]);
+         zcp->zc_word[3] = BSWAP_64(tmp.zc_word[3]);
  }