The M1 bus fabric is very picky about access modes. We had to add a whole new ioremap_np() to the kernel, because it requires nGnRnE mappings for on-die periphe

The M1 bus fabric is very picky about access modes. We had to add a whole new ioremap_np() to the kernel, because it requires nGnRnE mappings for on-die peripherals, while Linux used nGnRE for everything on ARM64 until now. For PCIe BARs it wants nGnRE instead, and I'll be very surprised if it'll take a normal mapping...