Re: [kvm-unit-tests PATCH v8 01/12] s390x: Use PSW bits definitions in cstart

[Thomas Huth <thuth@redhat.com>]

On 08/06/2020 17.28, Pierre Morel wrote:
> 
> 
> On 2020-06-08 16:52, Thomas Huth wrote:
>> On 08/06/2020 16.33, Pierre Morel wrote:
>>>
>>>
>>> On 2020-06-08 10:43, Thomas Huth wrote:
>>>> On 08/06/2020 10.12, Pierre Morel wrote:
>>>>> This patch defines the PSW bits EA/BA used to initialize the PSW masks
>>>>> for exceptions.
>>>>>
>>>>> Since some PSW mask definitions exist already in arch_def.h we add
>>>>> these
>>>>> definitions there.
>>>>> We move all PSW definitions together and protect assembler code
>>>>> against
>>>>> C syntax.
>>>>>
>>>>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>>>>> Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
>>>>> ---
>>>>>    lib/s390x/asm/arch_def.h | 15 +++++++++++----
>>>>>    s390x/cstart64.S         | 15 ++++++++-------
>>>>>    2 files changed, 19 insertions(+), 11 deletions(-)
>>>>>
>>>>> diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
>>>>> index 1b3bb0c..5388114 100644
>>>>> --- a/lib/s390x/asm/arch_def.h
>>>>> +++ b/lib/s390x/asm/arch_def.h
>>>>> @@ -10,15 +10,21 @@
>>>>>    #ifndef _ASM_S390X_ARCH_DEF_H_
>>>>>    #define _ASM_S390X_ARCH_DEF_H_
>>>>>    +#define PSW_MASK_EXT            0x0100000000000000UL
>>>>> +#define PSW_MASK_DAT            0x0400000000000000UL
>>>>> +#define PSW_MASK_SHORT_PSW        0x0008000000000000UL
>>>>> +#define PSW_MASK_PSTATE            0x0001000000000000UL
>>>>> +#define PSW_MASK_BA            0x0000000080000000UL
>>>>> +#define PSW_MASK_EA            0x0000000100000000UL
>>>>> +
>>>>> +#define PSW_EXCEPTION_MASK    (PSW_MASK_EA | PSW_MASK_BA)
>>>>
>>>> PSW_EXCEPTION_MASK sounds a little bit unfortunate - that term rather
>>>> reminds me of something that disables some interrupts
>>>> ... in case you
>>>> respin, maybe rather use something like "PSW_EXC_ADDR_MODE" ?
>>>
>>> EXCEPTIONS_PSW_MASK ?
>>
>> I think it is the _MASK suffix that mainly bugs me here, since this is
>> not a define that you normally use for extracting the bits from a PSW...
>> so EXCEPTIONS_PSW without _MASK would be fine for me... but as long as
>> I'm the only one who has a strange feeling about this, it's also ok if
>> you keep the current name.
>>
>>   Thomas
>>
> 
> The _MASK is because it is applied to the psw.mask and not to the
> psw.addr part.
> 
> But I agree that the name is not good, to keep the naming convention,
> may be it should be:
> 
> PSW_MASK_ON_EXCEPTION
> 
> beginning with PSW_MASK_ like all other psw.mask definitions and
> ON_EXCEPTION clearly define when it is used.

Good idea, PSW_MASK_ON_EXCEPTION sounds better for me, too!

 Thomas