[amdgpu] [ppc64le] AMDGPU crashes on boot when using 64k Page Size.

Brief summary of the problem:

AMDGPU crashes when used with 64K Page Size kernel on 5.10.x 4k page sizes appear to be unaffected. This issue first started appearing in Kernel 5.9.

I've attached the dmesg log.

Current known workarounds

1. Either: Compile kernel with 4k page size
2. Alternatively: use LTS Kernel 5.4.xx

Hardware description:

• CPU: Sforza POWER9 8-Core (x2)
• Motherboard: Raptor Computing Systems Talos II (T2P9D01 Rev 1.01)
• GPU: POWERCOLOR AMD Vega Rx 56 "Red Dragon"
• System Memory: 64GB
• Display(s): HP 24es (x2)
• Type of Diplay Connection: HDMI

System infomration:

• Distro name and Version: Gentoo
• Kernel version: 5.10.9 (little endian kernel)
• Custom kernel: No patches or customization beyond including the necessary drivers.
• AMD package version: x11-drivers/xf86-video-amdgpu-19.1.0

How to reproduce the issue:

• The issue is common to any kernels 5.9 and later, with 64k Page Sizes on this hardware.

Attached files:

• Dmesg log