Re: [PATCH] NOMMU: Stub out vm_get_page_prot() if there's no MMU

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Tue, Aug 24, 2010 at 11:22:38PM +0100, David Howells wrote:
> Stub out vm_get_page_prot() if there's no MMU.
> 
> This was added by commit:
> 
> 	commit 804af2cf6e7af31d2e664b54e657dddd9b531dbd
> 	Author: Hugh Dickins <hugh@veritas.com>
> 	Date:   Wed Jul 26 21:39:49 2006 +0100
> 	Subject: [AGPGART] remove private page protection map
> 
> and is used in commit:
> 
> 	commit c07fbfd17e614a76b194f371c5331e21e6cffb54
> 	Author: Daniel De Graaf <dgdegra@tycho.nsa.gov>
> 	Date:   Tue Aug 10 18:02:45 2010 -0700
> 	Subject: fbmem: VM_IO set, but not propagated
> 
> in the fbmem video driver, but the function doesn't exist on NOMMU, resulting
> in an undefined symbol at link time.
> 
> Signed-off-by: David Howells <dhowells@redhat.com>

Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Thanks for coming up with the patch!

> ---
> 
>  include/linux/mm.h |    8 ++++++++
>  1 files changed, 8 insertions(+), 0 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 709f672..6b258c5 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -1357,7 +1357,15 @@ static inline unsigned long vma_pages(struct vm_area_struct *vma)
>  	return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
>  }
>  
> +#ifdef CONFIG_MMU
>  pgprot_t vm_get_page_prot(unsigned long vm_flags);
> +#else
> +static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
> +{
> +	return __pgprot(0);
> +}
> +#endif
> +
>  struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
>  int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
>  			unsigned long pfn, unsigned long size, pgprot_t);