Re: [kvm-unit-tests PATCH v5 2/6] s390x: add function to set DAT mode for all interrupts

Nico Boehr
2023-07-14T10:38:27Z

Quoting Thomas Huth (2023-07-14 08:44:10)
> On 13/07/2023 17.30, Nico Boehr wrote:
> > Quoting Thomas Huth (2023-07-13 09:17:28)
> >> On 12/07/2023 13.41, Nico Boehr wrote:
> >>> When toggling DAT or switch address space modes, it is likely that
> >>> interrupts should be handled in the same DAT or address space mode.
> >>>
> >>> Add a function which toggles DAT and address space mode for all
> >>> interruptions, except restart interrupts.
> >>>
> >>> Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
> >>> ---
> >>> lib/s390x/asm/interrupt.h | 4 ++++
> >>> lib/s390x/interrupt.c | 36 ++++++++++++++++++++++++++++++++++++
> >>> lib/s390x/mmu.c | 5 +++--
> >>> 3 files changed, 43 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
> >>> index 35c1145f0349..55759002dce2 100644
> >>> --- a/lib/s390x/asm/interrupt.h
> >>> +++ b/lib/s390x/asm/interrupt.h
> >>> @@ -83,6 +83,10 @@ void expect_ext_int(void);
> >>> uint16_t clear_pgm_int(void);
> >>> void check_pgm_int_code(uint16_t code);
> >>>
> >>> +#define IRQ_DAT_ON true
> >>> +#define IRQ_DAT_OFF false
> >>
> >> Just a matter of taste, but IMHO having defines like this for just using
> >> them as boolean parameter to one function is a little bit overkill already.
> >> I'd rather rename the "bool dat" below into "bool use_dat" and then use
> >> "true" and "false" directly as a parameter for that function instead.
> >> Anyway, just my 0.02 \u20ac.
> >
> > The point of having these defines was to convey the meaning of the parameter to my reader.
> >
> > When I read
> >
> > irq_set_dat_mode(true, AS_HOME);
> >
> > it's less clear to me that the first parameter toggles the DAT mode compared to this:
> >
> > irq_set_dat_mode(IRQ_DAT_ON, AS_HOME);
> >
> > That being said, here it's pretty clear from the function name what the first parameter is, so what's the preferred opinion?
>
> I see your point, but if it is clear from the function name like it is in
> this case, I'd go with "true" and "false" directly, without the indirection
> via #define.

OK, will do.

> ...
> >>> + * Since enabling DAT needs initalized CRs and the restart new PSW is often used
> >>
> >> s/initalized/initialized/
> >
> > Argh, thanks.
> >
> > *reprioritizes task to look for a spell checker*
>
> codespell (https://github.com/codespell-project/codespell) is your friend!

Thanks!