How kernel derive irq number for particular irq line

[Greg KH]

On Mon, Jun 25, 2018 at 12:17:06AM +0530, Abhinav Misra wrote:
> Hi Guys,
> 
> I want to know how the irq number is derived in linux kernel.

It all depends on your platform.  It either comes from the firmware/bios
or it is in the device tree information.  The kernel itself doesn't know
this information, it has to be told that from an external source.

Hope this helps,

greg k-h