Re: [PATCH v4 6/6] arch: Move initrd= parsing into do_mounts_initrd.c

From: Florian Fainelli
Date: Mon Nov 12 2018 - 19:53:19 EST


On 11/12/18 4:40 PM, Vineet Gupta wrote:
> On 11/12/18 4:38 PM, Florian Fainelli wrote:
>>>> #ifdef CONFIG_BLK_DEV_INITRD
>>>> - if (initrd_start)
>>>> - memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
>>>> + if (phys_initrd_size) {
>>>> + memblock_reserve(phys_initrd_start, phys_initrd_size);
>>>> + initrd_start = (unsigned long)__va(phys_initrd_start);
>>>> + initrd_end = initrd_start + phys_initrd_size;
>>>> + }
>>>> #endif
>>> The common code now uses phys_initrd*, and you also use the same in ARC code, do
>>> we still need the initrd_* setting here ?
>>> ARC semantics was using them as PA anyways.
>> Yes, the generic initrd code expects initrd_start/end to be virtual
>> addresses, which we now directly derive from phys_initrd_start, that
>> should really be equivalent.
>
> So we can skip this explicit setting above - ARC arch code doesn't access the virt
> initrd_start

OK, you are saying we could just have the generic initrd code do this
assignment instead of having each architecture do it, is that a correct
understanding? If so, I suppose it could be done, whether as of this
patch series or as a follow-up, either way is fine with me.

One possible caveat is if __va() and __phys_to_virt() behave differently
(e.g: because of CONFIG_DEBUG_VIRTUAL or other things).
--
Florian