[PATCH] arm64: crypto: increase AES interleave to 4x

[Will Deacon]

On Thu, Feb 19, 2015 at 05:25:16PM +0000, Ard Biesheuvel wrote:
> This patch increases the interleave factor for parallel AES modes
> to 4x. This improves performance on Cortex-A57 by ~35%. This is
> due to the 3-cycle latency of AES instructions on the A57's
> relatively deep pipeline (compared to Cortex-A53 where the AES
> instruction latency is only 2 cycles).
> 
> At the same time, disable inline expansion of the core AES functions,
> as the performance benefit of this feature is negligible.
> 
>   Measured on AMD Seattle (using tcrypt.ko mode=500 sec=1):
> 
>   Baseline (2x interleave, inline expansion)
>   ------------------------------------------
>   testing speed of async cbc(aes) (cbc-aes-ce) decryption
>   test 4 (128 bit key, 8192 byte blocks): 95545 operations in 1 seconds
>   test 14 (256 bit key, 8192 byte blocks): 68496 operations in 1 seconds
> 
>   This patch (4x interleave, no inline expansion)
>   -----------------------------------------------
>   testing speed of async cbc(aes) (cbc-aes-ce) decryption
>   test 4 (128 bit key, 8192 byte blocks): 124735 operations in 1 seconds
>   test 14 (256 bit key, 8192 byte blocks): 92328 operations in 1 seconds

Fine by me. Shall I queue this via the arm64 tree?

Will

> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
> ---
>  arch/arm64/crypto/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile
> index 5720608c50b1..abb79b3cfcfe 100644
> --- a/arch/arm64/crypto/Makefile
> +++ b/arch/arm64/crypto/Makefile
> @@ -29,7 +29,7 @@ aes-ce-blk-y := aes-glue-ce.o aes-ce.o
>  obj-$(CONFIG_CRYPTO_AES_ARM64_NEON_BLK) += aes-neon-blk.o
>  aes-neon-blk-y := aes-glue-neon.o aes-neon.o
>  
> -AFLAGS_aes-ce.o		:= -DINTERLEAVE=2 -DINTERLEAVE_INLINE
> +AFLAGS_aes-ce.o		:= -DINTERLEAVE=4
>  AFLAGS_aes-neon.o	:= -DINTERLEAVE=4
>  
>  CFLAGS_aes-glue-ce.o	:= -DUSE_V8_CRYPTO_EXTENSIONS
> -- 
> 1.8.3.2
> 
>