[POWERPC] spufs: Synchronize pte invalidation vs ps close

Make sure the mapping_lock also protects access to the various address_space
pointers used for tearing down the ptes on a spu context switch.

Because unmap_mapping_range can sleep we need to turn mapping_lock from
a spinlock into a sleeping mutex.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --cc arch/powerpc/platforms/cell/spufs/context.c
Simple merge

diff --cc arch/powerpc/platforms/cell/spufs/file.c
Simple merge

diff --cc arch/powerpc/platforms/cell/spufs/spufs.h
Simple merge