Re: [PATCH 1/2] mtd: fix wrong usage of ioremap_nocache() in uclinux.c map driver

[Greg Ungerer <gerg@snapgear.com>]

On 12/07/12 17:49, David Woodhouse wrote:
> On Mon, 2012-07-09 at 16:08 +1000, Greg Ungerer wrote:
>>
>> The only VM based arch this driver can be configured for currently
>> is m68k (actually it is even more specific, only CONFIG_COLDFIRE).
>> And that doesn't support HIGHMEM.
>
> OK, can we at least have a comment to that effect in the code, alongside
> that phys_to_virt() call so that nobody is tempted to copy it into new
> code? And preferably also an '#ifdef CONFIG_HIGHMEM / #error' in the
> code or a (redundant) !HIGHMEM dependency in Kconfig just to make sure,
> in case it's ever enabled on other architectures or in case HIGHMEM ever
> comes to m68k.

I'll come up with something and send a patch.


>> Can the kernels data region (and the area immediately after it) be in
>> high memory?
>
> No, that'll be in the directly mapped region.

Then does it matter whether HIGHMEM is enabled or not?
The phys address here is _ebss, the end of the kernels bss section.

Regards
Greg



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Greg Ungerer  --  Principal Engineer        EMAIL:     gerg@snapgear.com
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