[PATCH] powerpc/pseries hotplug: prevent the reserved mem from removing

[Liu ping fan]

On Fri, Apr 28, 2017 at 2:06 AM, Hari Bathini
<hbathini at linux.vnet.ibm.com> wrote:
> Hi Pingfan,
>
>
> On Thursday 27 April 2017 01:13 PM, Pingfan Liu wrote:
>>
>> E.g after fadump reserves mem regions, these regions should not be removed
>> before fadump explicitly free them.
>> Signed-off-by: Pingfan Liu <piliu at redhat.com>
>> ---
>>   arch/powerpc/platforms/pseries/hotplug-memory.c | 5 +++--
>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
>> b/arch/powerpc/platforms/pseries/hotplug-memory.c
>> index e104c71..201be23 100644
>> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
>> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
>> @@ -346,6 +346,8 @@ static int pseries_remove_memblock(unsigned long base,
>> unsigned int memblock_siz
>>
>>         if (!pfn_valid(start_pfn))
>>                 goto out;
>> +       if (memblock_is_reserved(base))
>> +               return -EINVAL;
>
>
> I think memblock reserved regions are not hot removed even without this
> patch.
> So, can you elaborate on when/why this patch is needed?
>
I have not found code to prevent the reserved regions from free. Do I
miss anything?
I will try to reserve a ppc to have a test.

Thx,
Pingfan