Messages in this thread | | | Date | Thu, 10 Apr 2008 22:24:54 +0400 | From | Sergei Shtylyov <> | Subject | Re: [PATCH 6/13] devres: implement managed iomap interface |
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Kumar Gala wrote:
>>>>> Those functions are going to break on 32-bit platforms with >>>>> extended physical address (well, that's starting with Pentiums >>>>> which had 36-bit PAE :-) AND devices mapped beyond 4 GB (e.g. >>>>> PowerPC 44x). You should have used resource_size_t for the >>>>> 'offset' parameter. As this most probably means that libata is >>>>> broken on such platforms, I'm going to submit a patch...
>>> It's broken with drivers using MMIO, I meant to say.
>> Oops, I meant PCI drivers here, at least for the time being. And it >> looks like that was a false alarm. :-]
>>>> 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.
>> I thought that pcim_iomap() used devm_ioremap() or something -- >> which of course turned to be wrong. devm_ioremap() alone is yet safe >> since there are no users for it amongst PPC 44x platform device >> drivers...
> but there is no reason not to make it work properly. For example I > believe libata uses devm_* and the fsl SATA driver (non-PCI) will need > to work in cases similar to the 44x.
Well, as for sata_fsl, it calls of_iomap() which does The Right Thing.
> - k
WBR, Sergei
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