Support for multiple MSI with ARM platform

[Pratyush Anand]

Hi All,

I am using a PCIE device having MSI capability. It sends 4 different MSI vecotrs to host controller. 
The host controller which I am using is based on ARM platform( SPEAr).

Currently, arch_setup_msi_irqs function (which may be replaced by arch specific code) is not defined
for ARM. So my code used one default definition in driver/pci/msi.c But this code does not support 
multiple MSI.

what would be the best way to do it:

1. add following defines in arch/arm/include/asm/pci.h

#define arch_setup_msi_irqs arch_setup_msi_irqs

and then define this function in arch/arm/mach-xxxx/msi.c
or.

2. add following defines in arch/arm/include/asm/pci.h

#define arch_setup_msi_irqs arch_setup_msi_irqs

and then define this function in arch/arm/kernel/msi.c.
Now call some mach sepicif function from this routine.

or.
3 any other better solution.

Regards
Pratyush