Enable XIVE XICS emulation mode for POWER9 interrupt controller

[jhibbits]

Summary

To ease transition to the new XIVE interrupt controller on POWER9 systems, IBM
added a XICS emulation mode, using OPAL calls in place of physical device
accesses. Add this capability to the existing XICS/XICP driver as a stopgap
measure before writing a full XIVE native driver.

Test Plan

In progress. Not yet sure if this is a complete implementation, no
external interrupts are currently generated, possibly due to PCI configuration
issues, to resolve separately.

[nwhitehorn]

sys/powerpc/pseries/xics.c

185

Should we attach at lower priority for opal-xics? It's pretty near the bottom already, but maybe should be adjusted?

230

This needs #ifdef POWERNV.

[jhibbits]

sys/powerpc/pseries/xics.c

185

I think the XIVE driver should instead attach at BUS_PROBE_DEFAULT, a higher priority than this.

230

Woops, fixing.

[jhibbits]

Address Nathan's comments.

[jhibbits]

Tested with extra printfs last night, and saw no dispatches on IPI, but IPI sends. Something's not quite right yet, so more work is needed.

[breno.leitao_gmail.com]

Hi Justin,

I put some comments regarding OPAL_ definition I was not able to find in this patch and even on the FreeBSD HEAD repository.

sys/powerpc/pseries/xics.c

221

Justin,

I am not able to find the declaration of OPAL_XIVE_RESET. I just rebased my tree, and I still do not find this declaration. The same thing seems to happen with OPAL_INT_GET_XIRR, OPAL_INT_EOI , OPAL_INT_SET_MFRR and OPAL_INT_SET_CPPR.

Where did these definitions come from?

[jhibbits]

Add the OPAL definitions. There's also some printf debugging in here, which will go away when I figure out what's going wrong.

[jhibbits]

Abandoned in favor of D15492