Re: [Xen-devel] [PATCH V4] ns16550: Add support for UART present in Broadcom TruManage capable NetXtreme chips

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 22.11.13 at 14:09, Andrew Cooper <andrew.cooper3@xxxxxxxxxx> wrote:
> On 22/11/13 12:14, Jan Beulich wrote:
>>>>> On 22.11.13 at 11:44, Andrew Cooper <andrew.cooper3@xxxxxxxxxx> wrote:
>>> On 21/11/13 22:50, Aravind Gopalakrishnan wrote:
>>>>      if ( uart->remapped_io_base )
>>>> +    {
>>>> +        sfn = paddr_to_pfn((unsigned long) uart->io_base + PAGE_SIZE);
>>>> +        efn = paddr_to_pfn((unsigned long) uart->io_base + uart->io_size 
>>>> - 1);
>>>> +        if ( iomem_deny_access(dom0, sfn, efn) != 0 )
>>>> +            BUG();
>>> BUG_ON(!iomem_deny_access(dom0, sfn, efn))
>> Actually, we had more or less agreed to avoid side effects in
>> ASSERT() and BUG_ON() expressions (to eliminate the ambiguity
>> whether such expressions get always evaluated).
> 
> ASSERT()s certain, as the non-debug builds will optimise away call.
> 
> BUG/WARN_ON()s are different - they will be executed in all cases.

That's currently the case, but since it's different from ASSERT()
it's better to avoid the ambiguity.

Jan


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