eieio is only a store - store ordering. When used to order an unlock
operation loads may leak out of the critical region. This is potentially
buggy, one example is if a user wants to atomically read a couple of
values.

We can solve this with an lwsync which orders everything except store - load.

I removed the (now unused) EIEIO_ON_SMP macros and the c versions
isync_on_smp and eieio_on_smp now we dont use them. I also removed some
old comments that were used to identify inline spinlocks in assembly,
they dont make sense now our locks are out of line.

Another interesting thing was that read_unlock was using an eieio even
though the rest of the spinlock code had already been converted to
use lwsync.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

include/asm-ppc/ had #ifdef __KERNEL__ in all header files that
are not meant for use by user space, include/asm-powerpc does
not have this yet.

This patch gets us a lot closer there. There are a few cases
where I was not sure, so I left them out. I have verified
that no CONFIG_* symbols are used outside of __KERNEL__
any more and that there are no obvious compile errors when
including any of the headers in user space libraries.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

powerpc: Merge atomic.h and memory.h into powerpc

Merged atomic.h into include/powerpc.  Moved asm-style HMT_ defines from
memory.h into ppc_asm.h, where there were already HMT_defines; moved c-style
HMT_ defines to processor.h. Renamed memory.h to synch.h to better reflect
its contents.
Signed-off-by: NKumar Gala <kumar.gala@freescale.com>
Signed-off-by: NBecky Bruce <becky.bruce@freescale.com>
Signed-off-by: NJon Loeliger <linuxppc@jdl.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>