[patch][5/5] powerpc: Add the general support for Embedded Floating-Point instructions

[Benjamin Herrenschmidt]

> > Why do we need a separate ret_from_except_spe_full?
> 
> I'm not sure if the kernel will return from exception in a multi-thread
> way, but the truth is if restoring EVRs in exsiting ret_from_except_full,
> some non-SPE exception will try to retore EVR. At that time, the
> MSR[SPE] may not be enabled, which will cause error.

Hrm... you can restore them before returning from the exception if you
are careful about doing that with preempt/irqs off I suppose.

Ben.