Re: [XEN PATCH 7/8] x86/i8259: address MISRA C:2012 Rule 8.4

[Jan Beulich <jbeulich@xxxxxxxx>]

On 09.08.2023 22:15, Stefano Stabellini wrote:
> On Wed, 9 Aug 2023, Jan Beulich wrote:
>> On 09.08.2023 16:17, Nicola Vetrini wrote:
>>> On 09/08/2023 14:52, Jan Beulich wrote:
>>>> On 09.08.2023 13:02, Nicola Vetrini wrote:
>>>>> The additional header file makes the declaration for the function
>>>>> 'init_IRQ', defined in this file visible, thereby resolving the
>>>>> violation of Rule 8.4.
>>>>>
>>>>> No functional change.
>>>>>
>>>>> Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
>>>>> ---
>>>>>  xen/arch/x86/i8259.c | 1 +
>>>>>  1 file changed, 1 insertion(+)
>>>>>
>>>>> diff --git a/xen/arch/x86/i8259.c b/xen/arch/x86/i8259.c
>>>>> index 6b35be10f0..9b02a3a0ae 100644
>>>>> --- a/xen/arch/x86/i8259.c
>>>>> +++ b/xen/arch/x86/i8259.c
>>>>> @@ -19,6 +19,7 @@
>>>>>  #include <xen/delay.h>
>>>>>  #include <asm/apic.h>
>>>>>  #include <asm/asm_defns.h>
>>>>> +#include <asm/setup.h>
>>>>>  #include <io_ports.h>
>>>>>  #include <irq_vectors.h>
>>>>
>>>> A patch adding this #include has been pending for almost 3 months:
>>>> https://lists.xen.org/archives/html/xen-devel/2023-05/msg00896.html
>>>
>>> So do you prefer going forward with that patch or this one (mentioning 
>>> it
>>> in the additional commit context of course)?
>>
>> I would prefer using the much older patch, but of course this requires
>> someone providing R-b or A-b.
> 
> Hi Jan, normally I'd be happy to do that but that patch makes other
> changes that I don't feel confident enough to Ack.

I understand that in general, but for this specific case ...

> For instance:
> 
> +    for ( offs = 0, i = pic_alias_mask & -pic_alias_mask ?: 2;
> +          offs <= pic_alias_mask; offs += i )
> 
> pic_alias_mask is declared as unsigned int.

... you're concerned of me negating it? That's a common pattern to determine
the largest power-of-2 factor. I'm unaware of a good alternative.

Jan