[Skiboot] [PATCH] HBRT: fix clobbered r16 when host services handlers are called

[Vasant Hegde]

On 10/12/21 4:25 PM, Nicholas Piggin wrote:
> Skiboot is using r16 as a fixed register containing this CPU pointer,
> but we can be called back into from hostboot via the host services
> interface, where r16 may have been set by hostboot. Switch this back to
> skiboot's CPU pointer before running host services handlers, and then
> restore it to the hostboot value before returning.
> 
> Fixes: 11ce9612b3aa ("move the __this_cpu register to r16, reserve r13-r15")
> Reported-by: Frederic Barrat <fbarrat at linux.ibm.com>
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>

Thanks! Merged to master as ebef026.

-Vasant