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

[Jason Gunthorpe <jgg@nvidia.com>]

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?

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