[U-Boot] [PATCH] arc: add stubs for map_physmem() and unmap_physmem()

[Stephen Warren <swarren@wwwdotorg.org>]

On 11/13/2015 06:40 AM, Alexey Brodkin wrote:
> Hi Stephen,
>
> On Thu, 2015-11-12 at 16:00 -0700, Stephen Warren wrote:
>> On 11/12/2015 02:56 PM, Alexey Brodkin wrote:
>>> Up until now there was no need in those stubs.
>>>
>>> But since following commit compilation of U-Boot on ARC is broken:
>>> commit 7861204c9af7fec1ea9b41541c272516235a6c93
>>>       itest: make memory access work under sandbox
>>>
>> ...
>>> That's because CMD_ITEST is enabled by default in common/Kconfig and now
>>> map_physmem()/unmap_physmem() is used there.
>>>
>>> So this patch adds missing stubs for ARC.
>>
>> This looks OK, but rather than cut/pasting this exact same code yet
>> another time, why not create e.g. include/io-base.h that contains this,
>> and share it amongst all architectures?
>
> I did think about that.
>
> But the problem is "asm/io.h" is included in lots of sources and
> it's hard to tell a reason for that inclusion - if it's only because of
> map_physmem() or other stuff that might exist in the same header.
>
> For example lots of accessors are described in the same "asm/io.h" like
> readl(), writeb() etc.
>
> Frankly I'd prefer in that particular case to limit a change to my
> architecture.
>
> Still thoughts are welcome.

FWIW, I expected all the existing <asm/io.h> to simply include that new 
header in place of the duplicated code. Certainly, going through the 
entire source tree and adding #include statements for that new header 
would not be a good approach.