[PATCH] um: enable the use of optimized xor routines in UML

[Johannes Berg]

On Wed, 2020-11-11 at 15:01 +0000, anton.ivanov at cambridgegreys.com
wrote:
> 
> +++ b/arch/um/include/asm/xor.h
> @@ -1,7 +1,22 @@
>  /* SPDX-License-Identifier: GPL-2.0 */
> -#include <asm-generic/xor.h>
> +#ifndef _ASM_UM_XOR_H
> +#define _ASM_UM_XOR_H
> +
> +#ifdef CONFIG_64BIT
> +#undef CONFIG_X86_32
> +#else
> +#define CONFIG_X86_32 "Y"
> +#endif

Should that be '1' instead of '"Y"' to match what gets into the kernel's
autoconf.h, i.e. just '#define CONFIG_X86_32 1'?

Probably just used with #ifdef, but still, the string looks odd.

> +++ b/arch/um/kernel/um_arch.c
> @@ -48,9 +48,16 @@ static void __init add_arg(char *arg)
>   */
>  struct cpuinfo_um boot_cpu_data = {
>  	.loops_per_jiffy	= 0,
> -	.ipi_pipe		= { -1, -1 }
> +	.ipi_pipe		= { -1, -1 },
> +	.host_features		= 0

Don't _really_ need to 0-initialize, but also doesn't hurt :)
Might want to add a , at the end to make the next change easier.

> +const char* host_cpu_feature_names[] = {"mmx", "xmm", "avx", "rep_good", "erms"};
> +#define MAX_UM_CPU_FEATURES 5

Why the define rather than ARRAY_SIZE()?

johannes