Debugging x86_64 apic & bootup problems on the Cray XD1

[Troy Benjegerdes <hozer@hozed.org>]

I am attempting to make a 2.6.20 kernel boot on a Cray XD1 node with a
Mellanox InfiniBand card installed, however both the ancient supplied
cray 2.6.5 suse derivative, and a 2.6.20 kernel I just booted fail
on APIC initialization.

Below is a diff of boot-up logs from a node without the mellanox IB
card, and one with.. Does anyone have some pointers on debug options I
should start turning on? Is there some way I can disable some of the
memory regions in the infiniband card via some early PCI init code
before APIC's are set up?

  Processor #0 (Bootup-CPU)
  Processor #1
  I/O APIC #8 at 0xFEC00000.
- I/O APIC #11 at 0xFDC00100.    <- with IB card, misses APIC 9 & 10
- I/O APIC #12 at 0xFE400100.
+ I/O APIC #9 at 0xF8900000.
+ I/O APIC #10 at 0xF8901000.
+ I/O APIC #11 at 0xF9400100.
+ I/O APIC #12 at 0xF9C00100.
  Setting APIC routing to flat
  Processors: 2
  Nosave address range: 000000000009f000 - 00000000000a0000
  Nosave address range: 00000000000a0000 - 0000000000100000
  Nosave address range: 0000000000700000 - 0000000000c00000
  Allocating PCI resources starting at 88000000 (gap: 80000000:80000000)
  PERCPU: Allocating 33216 bytes of per cpu data
  Built 2 zonelists.  Total pages: 515735
  Kernel command line: root=/dev/nfs nfsroot=10.128.28.6:/var/opt/p
ce/nodewc/test1/448.5/root,rsize=1500,wsize=1500 rw no-scroll
console=ttyS0,1152                           00 amroot=5 hdb=non
e hdc=none hdd=none noacpi
  ide_setup: hdb=none
  ide_setup: hdc=none
  ide_setup: hdd=none

@@ -55,101 +65,12 @@
  CPU 0: aperture @ 80000000 size 2048 MB
  Aperture beyond 4GB. Ignoring.
  No AGP bridge found
  Memory: 2054720k/2097152k available (2617k kernel code, 36924k re
served, 1287k data, 328k init)
  Calibrating delay using timer specific routine.. 4391.46 BogoMIPS
(lpj=8782926)
  Security Framework v1.0.0 initialized
  Mount-cache hash table entries: 256
  CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
  CPU: L2 Cache: 1024K (64 bytes/line)
  CPU 0/0 -> Node 0
  Freeing SMP alternatives: 32k freed     <- with IB card, hangs here
- Using local APIC timer interrupts.      <- without IB card, continues