RE: [PATCH 12/37] xen/x86: decouple nodes_cover_memory from E820 map

[Wei Chen <Wei.Chen@xxxxxxx>]

Hi Jan,

> -----Original Message-----
> From: Jan Beulich <jbeulich@xxxxxxxx>
> Sent: 2022年1月27日 17:22
> To: Wei Chen <Wei.Chen@xxxxxxx>
> Cc: Bertrand Marquis <Bertrand.Marquis@xxxxxxx>; xen-
> devel@xxxxxxxxxxxxxxxxxxxx; sstabellini@xxxxxxxxxx; julien@xxxxxxx
> Subject: Re: [PATCH 12/37] xen/x86: decouple nodes_cover_memory from E820
> map
> 
> On 27.01.2022 10:03, Wei Chen wrote:
> >> From: Jan Beulich <jbeulich@xxxxxxxx>
> >> Sent: 2022年1月27日 16:09
> >>
> >> On 27.01.2022 09:03, Wei Chen wrote:
> >>>> From: Jan Beulich <jbeulich@xxxxxxxx>
> >>>> Sent: 2022年1月25日 0:59
> >>>>
> >>>> On 23.09.2021 14:02, Wei Chen wrote:
> >>>>> We will reuse nodes_cover_memory for Arm to check its bootmem
> >>>>> info. So we introduce two arch helpers to get memory map's
> >>>>> entry number and specified entry's range:
> >>>>>     arch_get_memory_bank_number
> >>>>>     arch_get_memory_bank_range
> >>>>
> >>>> I'm sorry, but personally I see no way for you to introduce the term
> >>>> "memory bank" into x86 code.
> >>>
> >>> In my latest changes, I have updated these two helpers to:
> >>> uint32_t __init arch_meminfo_get_nr_bank(void)
> >>> __init arch_meminfo_get_ram_bank_range(...)
> >>> I am sorry, I forgot to change the commit log accordingly.
> >>> I will update it in next version.
> >>
> >> I'm sorry for the ambiguity of my earlier reply, but my objection was
> >> against "bank", not "memory". As an aside, you also don't want the
> >
> > How about arch_meminfo_get_nr_map/ arch_meminfo_get_map_range?
> > I am sorry, I am not very familiar with e820 map, could you
> > give me some suggestions?
> 
> First of all I don't think you need a "get_nr" function at all, which
> eliminates the need to find a good name for it. The "get_range" function
> can easily provide back a unique indicator when the passed in index is
> beyond the number of regions. For this function's name, how about
> arch_get_memory_map() or arch_get_memory_map_block() or
> arch_get_memory_map_range() (in order of my personal preference)?
> 

Thanks, I will try to use arch_get_memory_map for x86 and arm.

> Jan