[PATCH 5/6] mm, x86: Add ARCH_HAS_ZONE_DEVICE

[Balbir Singh]

On Tue, May 23, 2017 at 2:05 PM, Oliver O'Halloran <oohall at gmail.com> wrote:
> Currently ZONE_DEVICE depends on X86_64. This is fine for now, but it
> will get unwieldly as new platforms get ZONE_DEVICE support. Moving it
> to an arch selected Kconfig option to save us some trouble in the
> future.
>
> Cc: x86 at kernel.org
> Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
> ---
>  arch/x86/Kconfig | 1 +
>  mm/Kconfig       | 5 ++++-
>  2 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index cd18994a9555..acbb15234562 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -59,6 +59,7 @@ config X86
>         select ARCH_HAS_STRICT_KERNEL_RWX
>         select ARCH_HAS_STRICT_MODULE_RWX
>         select ARCH_HAS_UBSAN_SANITIZE_ALL
> +       select ARCH_HAS_ZONE_DEVICE             if X86_64
>         select ARCH_HAVE_NMI_SAFE_CMPXCHG
>         select ARCH_MIGHT_HAVE_ACPI_PDC         if ACPI
>         select ARCH_MIGHT_HAVE_PC_PARPORT
> diff --git a/mm/Kconfig b/mm/Kconfig
> index beb7a455915d..2d38a4abe957 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -683,12 +683,15 @@ config IDLE_PAGE_TRACKING
>
>           See Documentation/vm/idle_page_tracking.txt for more details.
>
> +config ARCH_HAS_ZONE_DEVICE
> +       def_bool n
> +
>  config ZONE_DEVICE
>         bool "Device memory (pmem, etc...) hotplug support"
>         depends on MEMORY_HOTPLUG
>         depends on MEMORY_HOTREMOVE
>         depends on SPARSEMEM_VMEMMAP
> -       depends on X86_64 #arch_add_memory() comprehends device memory
> +       depends on ARCH_HAS_ZONE_DEVICE
>
>         help
>           Device memory hotplug support allows for establishing pmem,

Acked-by: Balbir Singh <bsingharora at gmail.com>