Re: [PATCH] arm/xen: Remove definiition of virt_to_pfn in asm/xen/page.h

From: Stefano Stabellini
Date: Fri Apr 25 2014 - 13:06:18 EST


On Thu, 24 Apr 2014, David Vrabel wrote:
> On 24/04/14 13:49, Julien Grall wrote:
> > Hi David,
> >
> > On 04/24/2014 01:22 PM, David Vrabel wrote:
> >> On 18/04/14 16:54, Julien Grall wrote:
> >>> virt_to_pfn has been defined in asm/memory.h by the commit e26a9e0 "ARM: Better
> >>> virt_to_page() handling"
> >>>
> >>> This will result of a compilation warning when CONFIG_XEN is enabled.
> >>>
> >>> arch/arm/include/asm/xen/page.h:80:0: warning: "virt_to_pfn" redefined [enabled by default]
> >>> #define virt_to_pfn(v) (PFN_DOWN(__pa(v)))
> >>> ^
> >>> In file included from arch/arm/include/asm/page.h:163:0,
> >>> from arch/arm/include/asm/xen/page.h:4,
> >>> from include/xen/page.h:4,
> >>> from arch/arm/xen/grant-table.c:33:
> >>>
> >>> The definition in memory.h is nearly the same (it directly expand PFN_DOWN),
> >>> so we can safely drop virt_to_pfn in xen include.
> >>
> >>
> >> This breaks the arm build for me.
> >>
> >> /local/davidvr/work/k.org/tip/drivers/block/xen-blkfront.c: In function
> >> âsetup_blkringâ:
> >> /local/davidvr/work/k.org/tip/drivers/block/xen-blkfront.c:1236:2:
> >> error: implicit declaration of function âvirt_to_pfnâ
> >> [-Werror=implicit-function-declaration]
> >> err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring));
> >> ^
> >
> > I don't have any issue to build the following branch with this patch on:
> > - v3.15-rc2
> > - xentip master
> > - xentip for-linus-3.16
>
> Applied to devel/for-linus-3.16.
>
> If something else turns up for 3.15 (and I remember) I'll take it for
> 3.15 instead.

David,
thank you very much for taking the patch in my absence.

Considering that the problem is affecting everybody enabling CONFIG_XEN
on ARM on v3.15, I don't think we can wait for the next merge window to
send this fix upstream.
Too many warnings for too many people.

Cheers,

Stefano