Re: [PATCH] Celleb: improve htab lock

We need to turn IRQs off when calling htab functions if and only
if it is non-atomic, so the "pSeries with LPAR" htab function have
no spin_lock or local_irq_save/restore. We think tweaking EE bit
locally gives a way to decrease times to be IRQs off and on again
(yes, it's smallthing to compare with calling HV),
so we prefer current implementation.

Well, it might be indeed worth keeping it that way to avoid long
latencies with EE off with a big batch... I'll keep it that way for now,
though I suppose I should add some documentation on the expected caller
context in machdep.h next to the function pointers.

Ben.