Re: Does io_remap_page_range() take 5 or 6 args?

[William Lee Irwin III <wli@holomorphy.com>]

On Wed, 18 Aug 2004 14:05:03 -0700 William Lee Irwin III wrote:
>> We should pass 64-bit values to remap_page_range() also, then. Or
>> perhaps passing pfn's to both suffices, as it all has to be page
>> aligned anyway.

On Wed, Aug 18, 2004 at 02:30:29PM -0700, David S. Miller wrote:
> Does not work on a system who has more physical address bits
> than 32 + PAGE_SHIFT
> Sparc32 does not fall into this category... but some other
> might.

All extant systems of this category I'm aware of are 32-bit kernels on
64-bit machines, which we don't really support. Also, the assumption
that physical addresses are bounded by 1ULL << (BITS_PER_LONG + PAGE_SHIFT)
is made broadly elsewhere, particularly in pfn_to_page() and the like.
Making this assumption in remap_page_range() and io_remap_page_range()
would save the overhead of passing additional arguments and/or passing
64-bit arguments on 32-bit machines. Using pgoff_t for pfn's may prove
useful for such systems, but it's highly doubtful the kernel will ever
be made clean for such or that they'll ever be brought to a usable state.


-- wli