Re: ohci1394 problem (MMIO broken) (was 2.6.25-rc6-git6: Reportedregressions from 2.6.24)

[Linus Torvalds]

On Sat, 22 Mar 2008, Stefan Richter wrote:
> 
> Can an MMIO region reside above 0x1'0000'0000 on x86-32? ... Apparently yes,
> if CONFIG_RESOURCES_64BIT=y.

Hmm. It would only work if PAE (HIGHMEM64G) is enabled too.

And obviously the hardware has to have working 64-bit BAR's.

AND no, I don't think our x86-32 ioremap() actually works for this case, 
because while the resource data may have the full 64 bits, when the 
ioremap() happens it gets truncated to 32 bits.

Ingo/Thomas - should ioremap*() perhaps take "resource_size_t" or a "u64" 
for the address (and then "__ioremap()" should probably take a PFN, not a 
physical address, and that one can remain just a "unsigned long"?)

Has anybody ever had a working 64-bit BAR on x86? Ivan? Maybe I'm missing 
something..

		Linus
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