Re: [net v3 PATCH] octeontx2-pf: Avoid typecasts by simplifying otx2_atomic64_add macro

[Simon Horman <horms@kernel.org>]

On Thu, May 29, 2025 at 07:04:48AM +0000, Subbaraya Sundeep wrote:
> Hi Simon,
> 
> On 2025-05-28 at 15:03:33, Simon Horman (horms@kernel.org) wrote:
> > On Wed, May 28, 2025 at 10:10:42AM +0530, Subbaraya Sundeep wrote:
> > > Just because otx2_atomic64_add is using u64 pointer as argument
> > > all callers has to typecast __iomem void pointers which inturn
> > > causing sparse warnings. Fix those by changing otx2_atomic64_add
> > > argument to void pointer.
> > > 
> > > Fixes: caa2da34fd25 ("octeontx2-pf: Initialize and config queues")
> > > Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
> > > ---
> > > v3:
> > >  Make otx2_atomic64_add as nop for architectures other than ARM64
> > >  to fix sparse warnings
> > > v2:
> > >  Fixed x86 build error of void pointer dereference reported by
> > >  kernel test robot
> > 
> > Sorry, I seem to have made some some comments on v2 after v3 was posted.
> > 
> > 1) I'm wondering if you considered changing the type of the 2nd parameter
> >    of otx2_atomic64_add to u64 __iomem * and, correspondingly, the type of
> 
> My intention is to fix sparse warnings (no __force) and avoid typecasts
> so that code is correct and looks cleaner. If I change 2nd param of
> otx2_atomics64_add as u64 __iomem * then I still have to use
> __force to make sparse happy. This way only otx2_atomic64_add looks odd
> internally with assembly stuff.

Thanks. Based on your remarks above I agree this is a good approach.

> 
> >    the local variables updated by this patch. Perhaps that isn't so clean
> >    for some reason. But if it can be done cleanly it does seem slightly
> >    nicer to me.
> >
> > 2) I wonder if this is more of a clean-up for net-next (once it re-opens,
> >    no Fixes tag) than a fix.
> > 
> Sure. Will post as net-next material later.

Again, thanks.