Subject: Re: [PATCH] powerpc/64s/radix: Define arch_ioremap_p4d_supported()

From: Stephen Rothwell <[email-masked]>
Date: Thu, 27 Jun 2019 10:06:17 +1000

Hi Anshuman,

On Wed, 26 Jun 2019 18:51:00 +0530 Anshuman Khandual <[email-masked]> wrote:
>
> Recent core ioremap changes require HAVE_ARCH_HUGE_VMAP subscribing archs
> provide arch_ioremap_p4d_supported() failing which will result in a build
> failure like the following.
> 
> ld: lib/ioremap.o: in function `.ioremap_huge_init':
> ioremap.c:(.init.text+0x3c): undefined reference to
> `.arch_ioremap_p4d_supported'
> 
> This defines a stub implementation for arch_ioremap_p4d_supported() keeping
> it disabled for now to fix the build problem.
> 
> Cc: Benjamin Herrenschmidt <[email-masked]>
> Cc: Paul Mackerras <[email-masked]>
> Cc: Michael Ellerman <[email-masked]>
> Cc: "Aneesh Kumar K.V" <[email-masked]>
> Cc: Nicholas Piggin <[email-masked]>
> Cc: Andrew Morton <[email-masked]>
> Cc: Stephen Rothwell <[email-masked]>
> Cc: [email-masked]
> Cc: [email-masked]
> Cc: [email-masked]
> 
> Signed-off-by: Anshuman Khandual <[email-masked]>
> ---
> This has been just build tested and fixes the problem reported earlier.
> 
>  arch/powerpc/mm/book3s64/radix_pgtable.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
> index 8904aa1..c81da88 100644
> --- a/arch/powerpc/mm/book3s64/radix_pgtable.c
> +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
> @@ -1124,6 +1124,11 @@ void radix__ptep_modify_prot_commit(struct vm_area_struct *vma,
>  	set_pte_at(mm, addr, ptep, pte);
>  }
>  
> +int __init arch_ioremap_p4d_supported(void)
> +{
> +	return 0;
> +}
> +
>  int __init arch_ioremap_pud_supported(void)
>  {
>  	/* HPT does not cope with large pages in the vmalloc area */
> -- 
> 2.7.4
> 

I will add that as a merge resolution patch for the akpm-current tree
merge today.

-- 
Cheers,
Stephen Rothwell