Linux SGI's on quad Cortex-A53


I have a quod Cortex-A53 system based on Xilinx Zynqmp SoC, and it uses Linux GiC_V2 driver.

I have configured the system to have the 2 cores running Linux, and the other 2 cores running custom software at EL3. I try to generate an SGI from the non-Linux running core to a Linux core but it does not work. I use 5.15 kernel.

I have tried to create a driver that is using similar functionality for IPI as seen on smp.c file of the arm64 arch directory. The driver registers correctly an IRQ outside the Linux IPI range The SGI id I use is 15 and I send the event to core0 - When I send the SGI event message from the non-linux to Linux I get a kernel panic:

Kernel panic - not syncing: FIQ taken without a root FIQ handler

If I send an SGI event the is within the Linux IPI range, I don't get any kernel Panic, but the IRQ IPI stats do not increase for the specific linux IPI event.

The deployed GIC_V2 has security features too.

I think something with the IRQ masks may be wrong. Is there any common practice to use SGI in Linux in a heterogeneous ArmV8 system?

Any ideas what or where to check would be very much appreciated.