On 04.01.19 09:42, Heiko Carstens wrote:
> On Thu, Jan 03, 2019 at 02:52:15PM +0100, Thomas Huth wrote:
>> On 2019-01-03 11:08, Janosch Frank wrote:
>>> +/*
>>> + * STCKE returns 16 bytes, which include the epoch, tod value and a
>>> + * programmable field. The value has to be trimmed to be able to work
>>> + * with it. As there's still some time to 2042, this code is not ready
>>> + * for multi epoch values.
>>> + */
>>> +static inline void stcke(char *tod)
>>> +{
>>> + asm volatile(
>>> + " stcke %[tod]\n"
>>> + : [tod] "=Q" (tod)
>>> + : : "cc");
>>> +}
>>
>> I'm not an inline-assembly wizzard, but the "=Q" constraint looks wrong
>> to me here. Are you sure that this is working as expected?
>
> Yes, this is wrong. That's the reason why the kernel variant has the
> typedef + cast (see get_tod_clock_ext() in arch/s390/include/asm/timex.h).
>
> The variant above tells the compiler that only a single byte is written to.
>
Yep, was removed yesterday already.
If tests for multi epoch enablement come up they'll have to introduce it
again.
For now I'll keep #12 and #13 on hold until they are needed upstream, I
think there will not be huge conflicts in that area if the need to
upstream it arises later.
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