[PATCH v2 1/4] arm64/mte: Document ABI for asymmetric mode

[Catalin Marinas]

On Wed, Feb 16, 2022 at 05:32:21PM +0000, Mark Brown wrote:
>  To allow a program to potentially run in the CPU's preferred tag
>  checking mode, the user program may set multiple tag check fault mode
>  bits in the ``flags`` argument to the ``prctl(PR_SET_TAGGED_ADDR_CTRL,
>  flags, 0, 0, 0)`` system call. If the CPU's preferred tag checking
> -mode is in the task's set of provided tag checking modes (this will
> -always be the case at present because the kernel only supports two
> -tag checking modes, but future kernels may support more modes), that
> +mode is in the task's set of provided tag checking modes, that
>  mode will be selected. Otherwise, one of the modes in the task's mode
> -set will be selected in a currently unspecified manner.
> +selected by the kernel using the preference order:
> +
> +	1. Asynchronous
> +	2. Asymmetric
> +	3. Synchronous
> +
> +If asymmetric mode is specified by the program but not supported by
> +either the system or the kernel then an error will be returned.

This works for me.

Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>