Re: [PATCH][for 2.6.28] powerpc/fsl-booke: Fix problem with _tlbil_va being interrupted

On Sat, 2008-12-13 at 17:33 -0600, Kumar Gala wrote:

An example calling sequence which we did see:

copy_user_highpage -> kmap_atomic -> flush_tlb_page -> _tlbil_va

We got interrupted after setting up the MAS registers before the
tlbwe and the interrupt handler that caused the interrupt also did
a kmap_atomic (ide code) and thus on returning from the interrupt
the MAS registers no longer contained the proper values.

Since we dont save/restore MAS registers for normal interrupts we
need to disable interrupts in _tlbil_va to ensure atomicity.

Signed-off-by: Kumar Gala <redacted>

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Paul, this is a 2.6.28 regression, it should probably go to Linus in
case he hasn't released yet :-)

Cheers,
Ben.