Re: [PATCH] Fix e820 end address with EFI

[Yinghai Lu <yinghai@kernel.org>]

Huang Ying wrote:
> On Mon, 2009-03-02 at 10:51 +0800, Yinghai Lu wrote:
>> On Sun, Mar 1, 2009 at 6:37 PM, Huang Ying <ying.huang@intel.com> wrote:
>>>> so 64bit could use ioremap_cache() too?
>>>> we may keep 32bit and 64bit a bit consistent.
>>> If we use ioremap_cache(), kexec runtime service will not work in kexec
>>> situation, which needs EFI runtime memory area to be mapped at exact
>>> same location across kexec. I think we should support kexec if possible.
>>
>> sure.
>>
>> please don't touch max_low_pfn_mapped, because some range may not
>> directly mapped under those efi run-time code
> 
> Find an issue to use init_memory_mapping() here.
> 
> If the memory range to be mapped is less than 2M, the last mapped
> address may be next 2M aligned position, this may lead mapping
> overlapping between memory range. Such as:
> 
> 0x3f388000 - 0x3f488000: real mapped	0x3f388000 - 0x3f600000
> 0x3f590000 - 0x3f5bb000: real mapped	0x3f590000 - 0x3f600000
> 
> The problem is that the memory range 0x3f400000 - 0x3f590000 is left not
> mapped!

what is max_low_pfn_mapped before that?

YH