[parisc-linux] save_specials performance

[Grant Grundler]

Hi john, paul,
if save_specials and rest_specials macros in include/asm-parisc/assembly.h
could trash both %r1 and %r2, would it double the speed of the
macros since the serial mfctl/mtctl could interleave register usage?

I understand %r2 would need to be saved some place first and that
might have it's own set of issues...but I suspect save/rest specials
is getting called alot.

thanks,
grant