Currently, we set the class bit in kernel SLB entries, and clear it on
user SLB entries.  On POWER5, ERAT entries created in real mode have
the class bit clear.  So to avoid flushing kernel ERAT entries on each
context switch, this patch inverts our usage of the class bit, setting
it on user SLB entries and clearing it on kernel SLB entries.

Booted on POWER5 and G5.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

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: NAnton Blanchard <anton@samba.org>
Acked-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!