I am using a powerpc processor booting with u-boot and running kernel 3.18, with 1G DDR RAM.

I configure a PCIe inbound window with u-boot from address 0x3FE00000 to 0x3FE200000(DDR goes from address 0x00000000 to 0x40000000).

Then, I boot the kernel and I keep PCIe inbound memory window as configured on u-boot. The kernel starts a process in charge of reading PCIe incoming messages by using mmap to read 0x3FE00000 PCIe inbound address, messages start being received and at some point, some of the processes running on kernel give a segmentation fault or an illegal instruction exception. If no PCIe messages are received, processes always run properly.

Should the PCIe inbound memory windows be reserved so that the kernel does not give an exception when receiving a new PCIe message? If so, how should I reserve these regions?Can they be configured through the device tree?

Thanks in advance,
Maria