[RFC] PPC64 Exporting memory information through /proc/iomem

[Badari Pulavarty]

On Wed, 2007-10-03 at 10:19 +0900, KAMEZAWA Hiroyuki wrote:
> On Tue, 02 Oct 2007 16:10:53 -0700
> Badari Pulavarty <pbadari at us.ibm.com> wrote:
> > > > Otherwise, we need to add arch-specific hooks in hotplug-remove
> > > > code to be able to do this.
> > > 
> > > Isn't it just a matter of abstracting the test for a valid range of
> > > memory?  If it's really hard to abstract that, then I guess we can put
> > > RAM in iomem_resource, but I'd rather not.
> > > 
> > 
> > Sure. I will work on it and see how ugly it looks.
> > 
> > KAME, are you okay with abstracting the find_next_system_ram() and
> > let arch provide whatever implementation they want ? (since current
> > code doesn't work for x86-64 also ?).
> > 
> Hmm, registering /proc/iomem is complicated ?

Its not complicated. Like Paul mentioned, its part of user/kernel API
which he is not prefering to break (if possible) + /proc/iomem seems
like a weird place to export conventional memory.

>  If too complicated, adding config
> like
> CONFIG_ARCH_SUPPORT_IORESOURCE_RAM or something can do good work.
> you can define your own "check_pages_isolated" (you can rename this to
> arch_check_apges_isolated().)

I was thinking more in the lines of 

CONFIG_ARCH_HAS_VALID_MEMORY_RANGE. Then define own
find_next_system_ram() (rename to is_valid_memory_range()) - which
checks the given range is a valid memory range for memory-remove
or not. What do you think ?

Thanks,
Badari