[POWERPC] spufs: Fix bitrot of the SPU mmap facility

It looks like we've had some serious bitrot there mostly due to tracking
of address_space's of mmap'ed files getting out of sync with the actual
mmap code. The mfc, mss and psmap were not tracked properly and thus
not invalidated on context switches (oops !)

I also removed the various file->f_mapping = inode->i_mapping;
assignments that were done in the other open() routines since that
is already done for us by __dentry_open.

One improvement we might want to do later is to assign the various
ctx-> fields at mmap time instead of file open/close time so that we
don't call unmap_mapping_range() on thing that have not been mmap'ed

Finally, I added some smp_wmb's after assigning the ctx-> fields to make
sure they are visible to other CPUs. I don't think this is really
necessary as I suspect locking in the fs layer will make that happen
anyway but better safe than sorry.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index 56864469215..0941c56df9b 100644
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -51,6 +51,8 @@ struct spu_context {
 	struct address_space *cntl; 	   /* 'control' area mappings. */
 	struct address_space *signal1; 	   /* 'signal1' area mappings. */
 	struct address_space *signal2; 	   /* 'signal2' area mappings. */
+	struct address_space *mss; 	   /* 'mss' area mappings. */
+	struct address_space *psmap; 	   /* 'psmap' area mappings. */
 	u64 object_id;		   /* user space pointer for oprofile */
 
 	enum { SPU_STATE_RUNNABLE, SPU_STATE_SAVED } state;