Re: [PATCH rdma-next V2 6/6] RDMA/core: Unify style of IOCTL commands

["Dalessandro, Dennis" <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

On Thu, 2016-09-01 at 19:20 +0300, Leon Romanovsky wrote:
> On Thu, Sep 01, 2016 at 02:05:44PM +0000, Dalessandro, Dennis wrote:
> > On Wed, 2016-08-24 at 00:31 +0300, Leon Romanovsky wrote:
> > > From: Leon Romanovsky <leonro@mellanox.com>
> > >  
> > > -#define HFI1_CMD_ASSIGN_CTXT     1	/* allocate HFI and
> > > context */
> > > -#define HFI1_CMD_CTXT_INFO       2	/* find out what
> > > resources
> > > we got */
> > > -#define HFI1_CMD_USER_INFO       3	/* set up userspace */
> > > -#define HFI1_CMD_TID_UPDATE      4	/* update expected TID
> > > entries */
> > > -#define HFI1_CMD_TID_FREE        5	/* free expected TID
> > > entries */
> > > -#define HFI1_CMD_CREDIT_UPD      6	/* force an update of
> > > PIO
> > > credit */
> > > +/* allocate HFI and context */
> > > +#define HFI1_CMD_ASSIGN_CTXT     (HFI1_CMD_BASE + 0x01)
> > > +/* find out what resources we got */
> > > +#define HFI1_CMD_CTXT_INFO       (HFI1_CMD_BASE + 0x02)
> > > +/* set up userspace */
> > > +#define HFI1_CMD_USER_INFO       (HFI1_CMD_BASE + 0x03)
> > > +/* update expected TID entries */
> > > +#define HFI1_CMD_TID_UPDATE      (HFI1_CMD_BASE + 0x04)
> > > +/* free expected TID entries */
> > > +#define HFI1_CMD_TID_FREE        (HFI1_CMD_BASE + 0x05)
> > > +/* force an update of PIO credit */
> > > +#define HFI1_CMD_CREDIT_UPD      (HFI1_CMD_BASE + 0x06)
> > 
> > This is a minor issue, but the problem here is when we build PSM
> > against this kernel it will no longer work for older kernels
> > because
> > the value of HFI1_CMD_ASSIGN_CTXT has changed where as it used to
> > be 1.
> > Right now PSM is backwards compatible, this breaks that
> > compatibility.
> > 
> > So while no one uses the __NUM() macro directly it lets us not
> > change
> > the PSM command values. Can we put that part back and keep the
> > command
> > values unchanged?
> 
> Sure, I'll post new version.
> Just to be sure, you are not using __NUM() and I can redefine that
> macro, am I right?
> 

Yeah you can call it something else, or do it in a different way. I
verified that the patch works with the current PSM reverting the CMD
numbers. I'll grab your new patch and re-test it then.

Thanks

-Denny