[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, 8 insertions, 4 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/context.c b/arch/powerpc/platforms/cell/spufs/context.c
index 0870009f56db..28c718ca3b51 100644
--- a/arch/powerpc/platforms/cell/spufs/context.c
+++ b/arch/powerpc/platforms/cell/spufs/context.c
@@ -111,13 +111,17 @@ void spu_unmap_mappings(struct spu_context *ctx)
 	if (ctx->local_store)
 		unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
 	if (ctx->mfc)
-		unmap_mapping_range(ctx->mfc, 0, 0x4000, 1);
+		unmap_mapping_range(ctx->mfc, 0, 0x1000, 1);
 	if (ctx->cntl)
-		unmap_mapping_range(ctx->cntl, 0, 0x4000, 1);
+		unmap_mapping_range(ctx->cntl, 0, 0x1000, 1);
 	if (ctx->signal1)
-		unmap_mapping_range(ctx->signal1, 0, 0x4000, 1);
+		unmap_mapping_range(ctx->signal1, 0, PAGE_SIZE, 1);
 	if (ctx->signal2)
-		unmap_mapping_range(ctx->signal2, 0, 0x4000, 1);
+		unmap_mapping_range(ctx->signal2, 0, PAGE_SIZE, 1);
+	if (ctx->mss)
+		unmap_mapping_range(ctx->mss, 0, 0x1000, 1);
+	if (ctx->psmap)
+		unmap_mapping_range(ctx->psmap, 0, 0x20000, 1);
 }
 
 int spu_acquire_exclusive(struct spu_context *ctx)