[PATCH 6/13] devres: implement managed iomap interface
Tejun Heo
htejun at gmail.com
Wed Apr 9 01:03:36 EST 2008
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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