[PATCH v12 11/40] arm64/sme: Identify supported SME vector lengths at boot

[Catalin Marinas]

On Fri, Feb 25, 2022 at 04:58:54PM +0000, Mark Brown wrote:
> The vector lengths used for SME are controlled through a similar set of
> registers to those for SVE and enumerated using a similar algorithm with
> some slight differences due to the fact that unlike SVE there are no
> restrictions on which combinations of vector lengths can be supported
> nor any mandatory vector lengths which must be implemented.  Add a new
> vector type and implement support for enumerating it.
> 
> One slightly awkward feature is that we need to read the current vector
> length using a different instruction (or enter streaming mode which
> would have the same issue and be higher cost).  Rather than add an ops
> structure we add special cases directly in the otherwise generic
> vec_probe_vqs() function, this is a bit inelegant but it's the only
> place where this is an issue.
> 
> Signed-off-by: Mark Brown <broonie at kernel.org>

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