How do I enable interrupts on second VME


Interrupts on the secondary (expansion) VME chassis are disabled by default.
When an expansion VME chassis is configured with a PowerMaxion or NightHawk
Turbo system, you need to enable the specific VME level for the desired CPU.
Here is the information from /etc/conf/mtune.d/bspall relating to interrupts
on the expansion chassis.  The example shown is for interrupt level 7:

* %%Tune%%      PICPU_LOCVME0_7
* %%Category%%  Interrupts
* %%Keywords%%  interrupt, i/o, routing, vme
* %%Abstract%%  enabling of the pci/exp vme interrupt on cpu 0.
* %%Extended%%  The interrupt from VME level 7 on the Expansion VME bus
* %%Extended%%  connected via CPU board 0 and/or the embedded PMC controller
* %%Extended%%  on CPU board 0 may be either disabled, handled by a local
* %%Extended%%  interrupt controller or routed to the frontplane
* %%Extended%%  for handling by another cpu.
* %%Extended%%  values are:
* %%Extended%%    -1 -  cpu selected via round-robin algorithm
* %%Extended%%    -3 -  disabled on all cpus
* %%Extended%%     0 -  board 0 pci A / exp VME 7 interrupt is handled
* %%Extended%%          locally by cpu 0 on processor card 0.
* %%Extended%%     1 -  board 0 pci A / exp VME 7  interrupt is handled
* %%Extended%%          locally by cpu 1 on processor card 0.
* %%Extended%%     2 -  board 0 pci A / exp VME 7 interrupt is routed to the
* %%Extended%%          frontplane and is handled globally by another cpu.
* %%Extended%%          The cpu handling the globally routed pci A/expansion
* %%Extended%%          VME 7 interrupts is specified by PICPU_EXP_VME_7.
* %%Extended%%  POWERMAXION NH6800T
* %%Tune_End%%
*
*                Default Min     Max
*                ------- ---     ---
PICPU_LOCVME0_7    -3    -3       2

You'll note that the default is -3, which  means disabled on all CPUs.  If
you choose to set it to '2', to route the interrupts through the frontplane,
you must modify the tunable PICPU_EXP_VME_7 (for this example) to specify
what CPU will handle it.  Here is the information on that tunable:

* %%Tune%%      PICPU_EXP_VME_7
* %%Category%%  Interrupts
* %%Keywords%%  interrupt, i/o, vme
* %%Abstract%%  cpu assignment for expansion vme level 7/PCI A0.
* %%Extended%%  Specifies the cpu that will receive this interrupt.  Allowed
* %%Extended%%  values are:
* %%Extended%%     -1  - cpu selected via round-robin algorithm
* %%Extended%%     -2  - boot cpu
* %%Extended%%     -3  - disabled on all cpus
* %%Extended%%     0-15 - specified logical cpu number
* %%Extended%%  POWERMAXION NH6800T
* %%Tune_End%%
*
*                Default Min     Max
*                ------- ---     ---
PICPU_EXP_VME_7    -3     -3     15

You'll see that the default is -3, disabled for all CPUs.  You may change
the value to -1 for round robin, -2 for the boot CPU, or give a positive
number to have the interrupts handled by a specific CPU.

Do not change this file directly.  To change the parameters, use config(1M)
or idtune(1M).  Then rebuild the system with /etc/conf/bin/idbuild -B, and
reboot the new kernel.