Moorestown systems crash on boot because the secondary CPU
clockevent (apbt1) will fail to request irq#1, which does not
have ioapic chip in its irq_desc[] entry.

Background:

Moorestown platform does not have ISA bus nor legacy IRQs. It
reuses the range of legacy IRQs for regular device interrupts.
The routing information of early system device IRQs (timers) are
obtained from firmware provided SFI tables. We reuse/fake MP
configuration table to facilitate IRQ setup with IOAPIC.

Maintaining a 1:1 mapping of IOAPIC pin (RTE entry) and IRQ#
makes routing information clean and easy to understand on
Moorestown. Though optional.

This patch allows SFI timer and vRTC IRQ to be treated as ISA
IRQ so that pin2irq mapping will be 1:1.

Also fixed MP table type and use macros to clearly set MP IRQ
entries. As a result, apbt timer and RTC interrupts on
Moorestown are within legacy IRQ range:

 # cat /proc/interrupts
            CPU0       CPU1
   0:      11249          0   IO-APIC-edge      apbt0
   1:          0      12271   IO-APIC-edge      apbt1
   8:        887          0   IO-APIC-fasteoi   dw_spi
  13:          0          0   IO-APIC-fasteoi   INTEL_MID_DMAC2
  14:          0          0   IO-APIC-fasteoi   rtc0

Further discussion of this patch can be found at:

  https://lkml.org/lkml/2010/6/10/70



Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Link: http://lkml.kernel.org/r/1302286980-21139-1-git-send-email-jacob.jun.pan@linux.intel.com


Signed-off-by: Ingo Molnar <mingo@elte.hu>