The iseries has a bar graph on the front panel that shows how busy it is.
The operating system sets and clears a bit in the CTRL register to control
it.
Instead of going to the complexity of using a thread info bit, just set and
clear it in the idle loop.
Also create two helper functions, ppc64_runlatch_on and ppc64_runlatch_off.
Finally don't use the short form of the SPR defines.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>