Re: [PATCH v2 04/10] s390x: smp: Test local interrupts after cpu reset

Janosch Frank
2020-04-24T11:51:52Z

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On 4/24/20 12:07 PM, David Hildenbrand wrote:
> On 23.04.20 11:10, Janosch Frank wrote:
>> Local interrupts (external and emergency call) should be cleared after
>> any cpu reset.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>> ---
>> s390x/smp.c | 22 ++++++++++++++++++++++
>> 1 file changed, 22 insertions(+)
>>
>> diff --git a/s390x/smp.c b/s390x/smp.c
>> index 8a6cd1d..a8e3dd7 100644
>> --- a/s390x/smp.c
>> +++ b/s390x/smp.c
>> @@ -243,6 +243,20 @@ static void test_reset_initial(void)
>> report_prefix_pop();
>> }
>>
>> +static void test_local_ints(void)
>> +{
>> + unsigned long mask;
>> +
>> + expect_ext_int();
>> + /* Open masks for ecall and emcall */
>> + ctl_set_bit(0, 13);
>> + ctl_set_bit(0, 14);
>> + mask = extract_psw_mask();
>> + mask |= PSW_MASK_EXT;
>> + load_psw_mask(mask);
>> + set_flag(1);
>> +}
>
> I think last time I looked at this I got it all wrong. So, we actually
> don't expect that an interrupt triggers here, correct?

Correct

>
> The SIGP_CPU_RESET should have cleared both interrupts on this cpu. So
> once we enable them, none should trigger.

Yes

>
> Why do we have "expect_ext_int()" ?

Excellent question, that should not be there.
Fortunately removing it doesn't change the test results.

>
>> +
>> static void test_reset(void)
>> {
>> struct psw psw;
>> @@ -251,10 +265,18 @@ static void test_reset(void)
>> psw.addr = (unsigned long)test_func;
>>
>> report_prefix_push("cpu reset");
>> + sigp(1, SIGP_EMERGENCY_SIGNAL, 0, NULL);
>> + sigp(1, SIGP_EXTERNAL_CALL, 0, NULL);
>> smp_cpu_start(1, psw);
>>
>> sigp_retry(1, SIGP_CPU_RESET, 0, NULL);
>> report(smp_cpu_stopped(1), "cpu stopped");
>> +
>> + set_flag(0);
>> + psw.addr = (unsigned long)test_local_ints;
>> + smp_cpu_start(1, psw);
>> + wait_for_flag();
>> + report(true, "local interrupts cleared");
>> report_prefix_pop();
>> }
>>
>>
>
>

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