Re: [PATCH] arm64/xen: redefine xen_remap on arm64

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

On Fri, 3 Jan 2014, Stefano Stabellini wrote:
> On Mon, 30 Dec 2013, Mark Salter wrote:
> > On Mon, 2013-12-30 at 14:55 +0800, Chen Baozi wrote:
> > > xen_remap used to be defined as ioremap_cached on arm64. In commit
> > > c04e8e2fe, a new ioremap_cache was implemented, and ioremap_cached
> > > was deleted, while xen_remap stays the same. This would lead to
> > > the failure when building with CONFIG_HVC_XEN. Redefined xen_remap
> > > on arm64 as ioremap_cache on arm64 to fix it.
> > > 
> > 
> > I missed that include of arm header by arm64 when looking for users
> > of arm64's ioremap_cached() when working on commit c04e8e2fe. Anyway,
> > grepping the kernel tree, I see:
> > 
> >   ioremap_cached()
> >     defined by: arm, metag, unicore32
> >     used by: arch/arm/include/asm/xen/page.h
> >              drivers/mtd/maps/pxa2xx-flash.c
> > 
> >   ioremap_cache()
> >     defined by: arm64, sh, xtensa, ia64, x86
> >     used by: drivers/video/vesafb.c
> >              drivers/char/toshiba.c
> >              drivers/acpi/apei
> >              drivers/lguest/lguest_device.c
> >              drivers/sfi/sfi_core.c
> >              include/linux/acpi_io.h
> > 
> > I think it would be better to just avoid the confusion and the ifdef in
> > asm/xen/page.h by globally changing ioremap_cached to ioremap_cache.
> 
> While I welcome the suggestion, this is a critical fix for a regression
> that I think should go in as soon as possible, maybe 3.13-rc7, while I
> don't think that a global s/ioremap_cached/ioremap_cache would be
> acceptable at this stage.

BTW Rob Herring sent a patch in November to solve the problem by
renaming ioremap_cached to ioremap_cache under arch/arm:

http://marc.info/?l=linux-arm-kernel&m=138394601804783

I wrongly assumed that was going to go in.
I think it is too late for that now. We'll have to go this this patch
for 3.13.