Re: [PATCH v5 3/8] xen/arm: return int from flush_page_to_ram and *_dcache_va_range

[Julien Grall <julien.grall@linaro.org>]

On 10/13/2014 03:58 PM, Stefano Stabellini wrote:
> These functions cannot really fail on ARM, but their x86 equivalents can
> (-EOPNOTSUPP). Change the prototype to return int.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  xen/arch/arm/mm.c          |    6 ++++--
>  xen/include/asm-arm/page.h |    8 +++++---
>  xen/include/asm-x86/page.h |    3 ++-
>  3 files changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
> index 996687b..f6f20aa 100644
> --- a/xen/arch/arm/mm.c
> +++ b/xen/arch/arm/mm.c
> @@ -377,12 +377,14 @@ unsigned long domain_page_map_to_mfn(const void *ptr)
>  }
>  #endif
>  
> -void flush_page_to_ram(unsigned long mfn)
> +int flush_page_to_ram(unsigned long mfn)

If you decide to change the prototype of flush_page_to_ram, you need to
check the return on every call-site.

IHMO, as this function is implemented as a no-op on x86, I would keep
the void and add an ASSERT below to check ret.

Regards,

-- 
Julien Grall