[PATCH 19/33] arm_mpam: Add a helper to touch an MSC from any CPU

[Shaopeng Tan (Fujitsu)]

> From: James Morse <james.morse at arm.com>
> 
> Resetting RIS entries from the cpuhp callback is easy as the callback occurs on
> the correct CPU. This won't be true for any other caller that wants to reset or
> configure an MSC.
> 
> Add a helper that schedules the provided function if necessary.
> 
> Callers should take the cpuhp lock to prevent the cpuhp callbacks from
> changing the MSC state.
> 
> Signed-off-by: James Morse <james.morse at arm.com>
> Reviewed-by: Ben Horgan <ben.horgan at arm.com>
> Reviewed-by: Jonathan Cameron <jonathan.cameron at huawei.com>
> Reviewed-by: Fenghua Yu <fenghuay at nvidia.com>
> Tested-by: Fenghua Yu <fenghuay at nvidia.com>
> Tested-by: Shaopeng Tan <tan.shaopeng at jp.fujitsu.com>
> Tested-by: Peter Newman <peternewman at google.com>
> Signed-off-by: Ben Horgan <ben.horgan at arm.com>

Reviewed-by: Shaopeng Tan <tan.shaopeng at jp.fujitsu.com>