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Age	Commit message (Collapse)	Author
2017-12-28	crypto: x86/twofish-3way - Fix %rbp usage	Eric Biggers
	Using %rbp as a temporary register breaks frame pointer convention and breaks stack traces when unwinding from an interrupt in the crypto code. In twofish-3way, we can't simply replace %rbp with another register because there are none available. Instead, we use the stack to hold the values that %rbp, %r11, and %r12 were holding previously. Each of these values represents the half of the output from the previous Feistel round that is being passed on unchanged to the following round. They are only used once per round, when they are exchanged with %rax, %rbx, and %rcx. As a result, we free up 3 registers (one per block) and can reassign them so that %rbp is not used, and additionally %r14 and %r15 are not used so they do not need to be saved/restored. There may be a small overhead caused by replacing 'xchg REG, REG' with the needed sequence 'mov MEM, REG; mov REG, MEM; mov REG, REG' once per round. But, counterintuitively, when I tested "ctr-twofish-3way" on a Haswell processor, the new version was actually about 2% faster. (Perhaps 'xchg' is not as well optimized as plain moves.) Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-01-20	crypto: x86/twofish - assembler clean-ups: use ENTRY/ENDPROC, localize jump ↵	Jussi Kivilinna
	labels Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2011-10-21	crypto: twofish - add 3-way parallel x86_64 assembler implemention	Jussi Kivilinna
	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>