[Skiboot] [PATCH 14/33] XIVE: Base XIVE support for OPAL XICS emulation calls

[Benjamin Herrenschmidt]

On Wed, 2016-07-06 at 17:48 +1000, Stewart Smith wrote:
> 
> +static int64_t opal_xive_eoi(uint32_t xirr)
> +
> +Not yet implemented.
> +
> +Modelled on the H_EOI PAPR call.

We should add that shall this return a positive value, more interrupts 
are queued for that CPU/priority and must be fetched as the XIVE is not
guaranteed to assert the CPU external interrupt line again until the
pending queue for the current priority has been emptied. 

> +For P9 and above systems where host doesn't know about interrupt
> controller.
> +An OS can instead make OPAL calls for XICS emulation.
> +
> +For an OS to use this OPAL call, an "ibm,opal-intc" compatible
> device must
> +exist in the device tree. If OPAL does not create such a device, the
> host
> +OS MUST NOT use this call.