[CRYPTO] twofish: i586 assembly version

The patch passed the trycpt tests and automated filesystem tests.
This rewrite resulted in some nice perfomance increase over my last patch.

Short summary of the tcrypt benchmarks:

Twofish Assembler vs. Twofish C (256bit 8kb block CBC)
encrypt: -33% Cycles
decrypt: -45% Cycles

Twofish Assembler vs. AES Assembler (128bit 8kb block CBC)
encrypt: +3%  Cycles
decrypt: -22% Cycles

Twofish Assembler vs. AES Assembler (256bit 8kb block CBC)
encrypt: -20% Cycles
decrypt: -36% Cycles

Full Output:
http://homepages.tu-darmstadt.de/~fritschi/twofish/tcrypt-speed-twofish-asm-i586.txt
http://homepages.tu-darmstadt.de/~fritschi/twofish/tcrypt-speed-twofish-c-i586.txt
http://homepages.tu-darmstadt.de/~fritschi/twofish/tcrypt-speed-aes-asm-i586.txt


Here is another bonnie++ benchmark with encrypted filesystems. All runs with
the twofish assembler modules max out the drivespeed. It should give some
idea what the module can do for encrypted filesystem performance even though
you can't see the full numbers.

http://homepages.tu-darmstadt.de/~fritschi/twofish/output_20060611_205432_x86.html

Signed-off-by: Joachim Fritschi <jfritschi@freenet.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 97 insertions, 0 deletions

diff --git a/arch/i386/crypto/twofish.c b/arch/i386/crypto/twofish.c
new file mode 100644
index 000000000000..e3004dfe9c7a
--- /dev/null
+++ b/arch/i386/crypto/twofish.c
@@ -0,0 +1,97 @@
+/*
+ *  Glue Code for optimized 586 assembler version of TWOFISH
+ *
+ * Originally Twofish for GPG
+ * By Matthew Skala <mskala@ansuz.sooke.bc.ca>, July 26, 1998
+ * 256-bit key length added March 20, 1999
+ * Some modifications to reduce the text size by Werner Koch, April, 1998
+ * Ported to the kerneli patch by Marc Mutz <Marc@Mutz.com>
+ * Ported to CryptoAPI by Colin Slater <hoho@tacomeat.net>
+ *
+ * The original author has disclaimed all copyright interest in this
+ * code and thus put it in the public domain. The subsequent authors
+ * have put this under the GNU General Public License.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
+ * USA
+ *
+ * This code is a "clean room" implementation, written from the paper
+ * _Twofish: A 128-Bit Block Cipher_ by Bruce Schneier, John Kelsey,
+ * Doug Whiting, David Wagner, Chris Hall, and Niels Ferguson, available
+ * through http://www.counterpane.com/twofish.html
+ *
+ * For background information on multiplication in finite fields, used for
+ * the matrix operations in the key schedule, see the book _Contemporary
+ * Abstract Algebra_ by Joseph A. Gallian, especially chapter 22 in the
+ * Third Edition.
+ */
+
+#include <crypto/twofish.h>
+#include <linux/crypto.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+
+asmlinkage void twofish_enc_blk(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
+asmlinkage void twofish_dec_blk(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
+
+static void twofish_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+        twofish_enc_blk(tfm, dst, src);
+}
+
+static void twofish_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+        twofish_dec_blk(tfm, dst, src);
+}
+
+static struct crypto_alg alg = {
+        .cra_name               =       "twofish",
+        .cra_driver_name        =       "twofish-i586",
+        .cra_priority           =       200,
+        .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
+        .cra_blocksize          =       TF_BLOCK_SIZE,
+        .cra_ctxsize            =       sizeof(struct twofish_ctx),
+        .cra_alignmask          =       3,
+        .cra_module             =       THIS_MODULE,
+        .cra_list               =       LIST_HEAD_INIT(alg.cra_list),
+        .cra_u                  =       {
+                .cipher = {
+                        .cia_min_keysize        =       TF_MIN_KEY_SIZE,
+                        .cia_max_keysize        =       TF_MAX_KEY_SIZE,
+                        .cia_setkey             =       twofish_setkey,
+                        .cia_encrypt            =       twofish_encrypt,
+                        .cia_decrypt            =       twofish_decrypt
+                }
+        }
+};
+
+static int __init init(void)
+{
+        return crypto_register_alg(&alg);
+}
+
+static void __exit fini(void)
+{
+        crypto_unregister_alg(&alg);
+}
+
+module_init(init);
+module_exit(fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION ("Twofish Cipher Algorithm, i586 asm optimized");
+MODULE_ALIAS("twofish");