[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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