[U-Boot] [PATCH v4 3/6] ARM: Add macros.h to be used in assembler file.

[Wolfgang Denk]

Dear Jean-Christophe PLAGNIOL-VILLARD,

In message <20090707202432.GK30172 at game.jcrosoft.org> you wrote:
>
> > > + * These macros provide a convenient way to write 8, 16 and 32 bit data
> > > + * to any address.
> > 
> > I think this comment might be wrong. It should probably read "...  to
> > any  _memory_ address". Using these macros to access device registers
> > and the like is probably nore recommended?
> you can access cpu register without problem with these macros

Is it guaranteed that none of the existing ARM architectures and  all
the  plethora  of  their  specific implementations of the zillions of
SoCs do not require any form  of  memory  barrier  instructions  when
accessing  device registers? Even when these are external peripherals
on some external bus?

Sorry for such a stupid question about things that are eventually
obvious to you, but I don't know ARM processors that well...

Best regards,

Wolfgang Denk

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