Re: [PATCH v2 07/10] s390x: smp: Use full PSW to bringup new cpu

David Hildenbrand
2020-04-24T11:23:43Z

On 24.04.20 13:16, Janosch Frank wrote:
> On 4/24/20 12:09 PM, David Hildenbrand wrote:
>> On 23.04.20 11:10, Janosch Frank wrote:
>>> Up to now we ignored the psw mask and only used the psw address when
>>> bringing up a new cpu. For DAT we need to also load the mask, so let's
>>> do that.
>>>
>>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>>> ---
>>> lib/s390x/smp.c | 2 ++
>>> s390x/cstart64.S | 3 ++-
>>> 2 files changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/lib/s390x/smp.c b/lib/s390x/smp.c
>>> index 3f86243..6ef0335 100644
>>> --- a/lib/s390x/smp.c
>>> +++ b/lib/s390x/smp.c
>>> @@ -202,6 +202,8 @@ int smp_cpu_setup(uint16_t addr, struct psw psw)
>>> cpu->stack = (uint64_t *)alloc_pages(2);
>>>
>>> /* Start without DAT and any other mask bits. */
>>> + cpu->lowcore->sw_int_psw.mask = psw.mask;
>>> + cpu->lowcore->sw_int_psw.addr = psw.addr;
>>> cpu->lowcore->sw_int_grs[14] = psw.addr;
>>
>> Do we still have to set sw_int_grs[14] ?
>>
> r14 is saved to restart_new so we don't go through setup twice.
> We could instead copy cpu->lowcore->sw_int_psw.addr to restart new, but
> that means more changes than the removal of one line.
>
> Also, what about backtraces or plain old debug?
> Having r14 is a good backup to have IMHO.
>

Fine with me

Reviewed-by: David Hildenbrand <david@redhat.com>

--
Thanks,

David / dhildenb