Desire to allocate bit in DT_PARM bitmask for DEC FORMAT compatibility purposes

[Jerry DeLisle]

On 03/23/2018 02:01 AM, Janne Blomqvist wrote:
> On Fri, Mar 23, 2018 at 4:07 AM, Jerry DeLisle <jvdelisle@charter.net>
> wrote:
> 
>>
>>
>> Reserving the bit is OK with me, doing so does no harm and it does not
>> break the ABI.
> 
> 
> Come to think of it, as we're now quite close to the end of that flag
> variable, should we add a flags2 variable to dt_parm just in case to avoid
> breaking the ABI when we need more bits?
> 

Very good point. We already had to do this for inquire:

#define IOPARM_INQUIRE_HAS_FLAGS2	(1u << 31)

So if we do the extension bit, please also add the flags 2 at the end 
similarly and add the next set of bits.

IIRC it needs to be in st_parameter_common.

Jerry