crypto: twofish - add 3-way parallel x86_64 assembler implemention

Patch adds 3-way parallel x86_64 assembly implementation of twofish as new
module. New assembler functions crypt data in three blocks chunks, improving
cipher performance on out-of-order CPUs.

Patch has been tested with tcrypt and automated filesystem tests.

Summary of the tcrypt benchmarks:

Twofish 3-way-asm vs twofish asm (128bit 8kb block ECB)
 encrypt: 1.3x speed
 decrypt: 1.3x speed

Twofish 3-way-asm vs twofish asm (128bit 8kb block CBC)
 encrypt: 1.07x speed
 decrypt: 1.4x speed

Twofish 3-way-asm vs twofish asm (128bit 8kb block CTR)
 encrypt: 1.4x speed

Twofish 3-way-asm vs AES asm (128bit 8kb block ECB)
 encrypt: 1.0x speed
 decrypt: 1.0x speed

Twofish 3-way-asm vs AES asm (128bit 8kb block CBC)
 encrypt: 0.84x speed
 decrypt: 1.09x speed

Twofish 3-way-asm vs AES asm (128bit 8kb block CTR)
 encrypt: 1.15x speed

Full output:
 http://koti.mbnet.fi/axh/kernel/crypto/tcrypt-speed-twofish-3way-asm-x86_64.txt
 http://koti.mbnet.fi/axh/kernel/crypto/tcrypt-speed-twofish-asm-x86_64.txt
 http://koti.mbnet.fi/axh/kernel/crypto/tcrypt-speed-aes-asm-x86_64.txt

Tests were run on:
 vendor_id  : AuthenticAMD
 cpu family : 16
 model      : 10
 model name : AMD Phenom(tm) II X6 1055T Processor

Also userspace test were run on:
 vendor_id  : GenuineIntel
 cpu family : 6
 model      : 15
 model name : Intel(R) Xeon(R) CPU           E7330  @ 2.40GHz
 stepping   : 11

Userspace test results:

Encryption/decryption of twofish 3-way vs x86_64-asm on AMD Phenom II:
 encrypt: 1.27x
 decrypt: 1.25x

Encryption/decryption of twofish 3-way vs x86_64-asm on Intel Xeon E7330:
 encrypt: 1.36x
 decrypt: 1.36x

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 0763774..404a846 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -828,6 +828,26 @@
 	  See also:
 	  <http://www.schneier.com/twofish.html>
 
+config CRYPTO_TWOFISH_X86_64_3WAY
+	tristate "Twofish cipher algorithm (x86_64, 3-way parallel)"
+	depends on (X86 || UML_X86) && 64BIT
+	select CRYPTO_ALGAPI
+	select CRYPTO_TWOFISH_COMMON
+	select CRYPTO_TWOFISH_X86_64
+	help
+	  Twofish cipher algorithm (x86_64, 3-way parallel).
+
+	  Twofish was submitted as an AES (Advanced Encryption Standard)
+	  candidate cipher by researchers at CounterPane Systems.  It is a
+	  16 round block cipher supporting key sizes of 128, 192, and 256
+	  bits.
+
+	  This module provides Twofish cipher algorithm that processes three
+	  blocks parallel, utilizing resources of out-of-order CPUs better.
+
+	  See also:
+	  <http://www.schneier.com/twofish.html>
+
 comment "Compression"
 
 config CRYPTO_DEFLATE