Re: [PATCH 2/2] SHA1 transform: x86_64 AVX2 optimization - glue & build - resend with email correction

[Jussi Kivilinna <jussi.kivilinna@iki.fi>]

On 27.02.2014 19:42, chandramouli narayanan wrote:
> This git patch adds the glue, build and configuration changes
> to include x86_64 AVX2 optimization of SHA1 transform to
> crypto support. The patch has been tested with 3.14.0-rc1
> kernel.
> 
> On a Haswell desktop, with turbo disabled and all cpus running
> at maximum frequency, tcrypt shows AVX2 performance improvement
> from 3% for 256 bytes update to 16% for 1024 bytes update over
> AVX implementation. 
> 
> Signed-off-by: Chandramouli Narayanan <mouli@linux.intel.com>
> 
<..snip..>
>  static int __init sha1_ssse3_mod_init(void)
>  {
> +	char *algo_name;
>  	/* test for SSSE3 first */
> -	if (cpu_has_ssse3)
> +	if (cpu_has_ssse3) {
>  		sha1_transform_asm = sha1_transform_ssse3;
> +		algo_name = "SSSE3";
> +	}
>  
>  #ifdef CONFIG_AS_AVX
>  	/* allow AVX to override SSSE3, it's a little faster */
> -	if (avx_usable())
> -		sha1_transform_asm = sha1_transform_avx;
> +	if (avx_usable()) {
> +		if (cpu_has_avx) {
> +			sha1_transform_asm = sha1_transform_avx;
> +			algo_name = "AVX";
> +		}
> +#ifdef CONFIG_AS_AVX2
> +		if (cpu_has_avx2) {

Wouldn't you need to check also for BMI2 as __sha1_transform_avx2 uses 'rorx'?

For example, commit 16c0c4e1656c14ef9deac189a4240b5ca19c6919 added BMI2 check for SHA-256.

-Jussi

> +			/* allow AVX2 to override AVX, it's a little faster */
> +			sha1_transform_asm = __sha1_transform_avx2;
> +			algo_name = "AVX2";
> +		}
> +#endif
> +	}
>  #endif