Re: [PATCH 1/7] mips: dmi: Fix early remap on MIPS32

[Jiaxun Yang]

在2023年11月23日十一月 下午4:07，Thomas Bogendoerfer写道：
> On Thu, Nov 23, 2023 at 03:07:09PM +0000, Jiaxun Yang wrote:
>> 
[...]
>
> the problem with all 32bit unmapped segments is their limitations in
> size. But there is always room to try to use unmapped and fall back
> to mapped, if it doesn't work. But I doubt anybody is going to
> implement that.

Yep, I guess fallback should be implemented for ioremap_cache as well.

>
>> >> AFAIK for Loongson DMI is located at cached memory so using ioremap_uc
>> >> blindly will cause inconsistency.
>> >
>> > why ?
>> 
>> Firmware sometimes does not flush those tables from cache back to memory.
>> For Loongson systems (as well as most MTI systems) cache is enabled by
>> firmware.
>
> kernel flushes all caches on startup, so there shouldn't be a problem.

Actually dmi_setup() is called before cpu_cache_init().

Thanks
>
> Thomas.
>
> -- 
> Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
> good idea.                                                [ RFC1925, 2.3 ]

-- 
- Jiaxun