MSI CPU affinity for ARM64

Hi,
I am trying to understand how we can find the target CPU for  MSI in ARM64.
When looking at gic_v3 code I can see following:
gic_v3_bind_intr( ) does mapping to next incremental CPU but gic_v3_dist_init( ) does setup boot cpu
as the target CPU for MSI interrupts.

If I need to find the CPU bound with a particular MSI interrupt, how we can do that?

Also is there a way get the the CPU id from the CPU affinity in ARM?

Thanks & Regards, 
Souradeep