Re: [REGRESSION] on linux-next (next-20250507)

[Leon Romanovsky <leon@kernel.org>]

On Wed, May 14, 2025 at 12:40:02PM +0000, Borah, Chaitanya Kumar wrote:
> 
> 
> > -----Original Message-----
> > From: Jason Gunthorpe <jgg@nvidia.com>
> > Sent: Monday, May 12, 2025 5:51 PM
> > To: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
> > Cc: intel-xe@lists.freedesktop.org; intel-gfx@lists.freedesktop.org; Saarinen,
> > Jani <jani.saarinen@intel.com>; Nikula, Jani <jani.nikula@intel.com>; Kurmi,
> > Suresh Kumar <suresh.kumar.kurmi@intel.com>; De Marchi, Lucas
> > <lucas.demarchi@intel.com>; iommu@lists.linux.dev
> > Subject: Re: [REGRESSION] on linux-next (next-20250507)
> > 
> > On Mon, May 12, 2025 at 06:00:39AM +0000, Borah, Chaitanya Kumar
> > wrote:
> > 
> > > ``````````````````````````````````````````````````````````````````````
> > > ```````````````````````````````````
> > > commit 13f43d7cf3e0570004a0d960bc1be23db827c2ff
> > > Author: Jason Gunthorpe mailto:jgg@nvidia.com
> > > Date:   Tue Apr 8 13:53:56 2025 -0300
> > >
> > >     iommu/pages: Formalize the freelist API
> > > ``````````````````````````````````````````````````````````````````````
> > > ```````````````````````````````````
> > >
> > > We could not revert the patch because of merge conflicts but resetting to the
> > parent of the commit seems to fix the issue.
> > >
> > > Could you please check why the patch causes this regression and provide a
> > fix if necessary?
> > 
> > Could this be the solution?
> 
> Apologies for the delay, this change seems to solve the issue. Can we expect a patch soon?

Jason is on vacation this week. I recommend to submit the patch by itself.

Thanks

> 
> Regards
> 
> Chaitanya
> 
> > 
> > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> > index 0af1ab36283cba..7d2b51a890c75a 100644
> > --- a/drivers/iommu/dma-iommu.c
> > +++ b/drivers/iommu/dma-iommu.c
> > @@ -154,6 +154,8 @@ static void fq_ring_free_locked(struct
> > iommu_dma_cookie *cookie, struct iova_fq
> >  			       fq->entries[idx].iova_pfn,
> >  			       fq->entries[idx].pages);
> > 
> > +		fq->entries[idx].freelist =
> > +			IOMMU_PAGES_LIST_INIT(fq->entries[idx].freelist);
> >  		fq->head = (fq->head + 1) & fq->mod_mask;
> >  	}
> >  }
> > 
> > Jason