Re: [PATCH 6/13] devres: implement managed iomap interface

From: Tejun Heo
Date: Tue Apr 08 2008 - 11:03:55 EST


Sergei Shtylyov wrote:
Yeah, right please go ahead. But I wonder whether any BIOS was actually crazy enough to map mmio region above 4G on 32bit machine.

This is a *hardware* mapping on some non-x86 platforms (like PPC 44x or MIPS Alchemy). The arch/ppc/ and arch/mips/ kernels have special hooks called from ioremap() which help create an illusion that the PCI memory space on such platforms (not only it) is mapped below 4 GB; arch/powerpc/ kernel doesn't do this anymore -- hence this newly encountered issue.

Ah... I see. Thanks for the clarification.

--
tejun
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