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J=C3=B6rn Engel wrote:
> Neither am I.  My missing puzzle piece is how to zap all page mappings
> for the chip in question.  Maybe the fs/vm meeting at lce will clear
> things up.
I don't think that one is particular hard to do. All you need is:
- count refernces in the driver
- make the xip code return its references after use
- a callback that the driver can call to get its references that are
   mapped to userland back which would simply boil down to=20
filemap_xip_unmap()
- the driver should stop handing out new references for file=20
operations when calling the callback, and the reference count should=20
become zero pretty soon.
I'd be happy to do the xip infrastructure parts of this.