Fold the SB-1 specific implementation of clear_page/copy_page in the
generic version, and rewrite that one in tlbex style. The immediate
benefits:
- It converts the compile-time workaround for SB-1 pass 1 prefetches
to a more efficient run-time check.
- It allows adjustment of loop unfolling, which helps to reduce the
number of redundant cdex cache ops.
- It fixes some esoteric cornercases (the cache line length calculations
can go wrong, and support for 64k pages without prefetch instructions
will overflow the addiu immediate).
- Somewhat better guesses of "good" prefetch values.
Signed-off-by: Thiemo Seufer <ths@networkno.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
