[PATCH] fsl_pamu: Use 40-bits for addressing where appropriate
Ben Collins
ben.collins at linux.dev
Wed Apr 23 08:21:32 AEST 2025
On Tue, Apr 22, 2025 at 04:09:21PM -0500, Jason Gunthorpe wrote:
> On Mon, Apr 21, 2025 at 10:46:19PM -0400, Ben Collins wrote:
> > diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
> > index 30be786bff11e..a4bc6482a00f7 100644
> > --- a/drivers/iommu/fsl_pamu_domain.c
> > +++ b/drivers/iommu/fsl_pamu_domain.c
> > @@ -214,9 +214,10 @@ static struct iommu_domain *fsl_pamu_domain_alloc(unsigned type)
> > INIT_LIST_HEAD(&dma_domain->devices);
> > spin_lock_init(&dma_domain->domain_lock);
> >
> > - /* default geometry 64 GB i.e. maximum system address */
> > + /* Set default geometry based on physical address limit. */
> > dma_domain->iommu_domain. geometry.aperture_start = 0;
> > - dma_domain->iommu_domain.geometry.aperture_end = (1ULL << 36) - 1;
> > + dma_domain->iommu_domain.geometry.aperture_end =
> > + (1ULL << PAMU_MAX_PHYS_BITS) - 1;
> > dma_domain->iommu_domain.geometry.force_aperture = true;
>
> What on earth does this even do? There is no map_range() callback in
> this driver, so nothing should be reading geometry..
I dunno, but your "FIXME this is broken" comments are all over it from a
year and a half ago:
Author: Jason Gunthorpe <jgg at ziepe.ca>
Date: Wed Sep 13 10:43:38 2023 -0300
iommu/fsl_pamu: Implement a PLATFORM domain
/*
* FIXME: This isn't creating an unmanaged domain since the
* default_domain_ops do not have any map/unmap function it doesn't meet
* the requirements for __IOMMU_DOMAIN_PAGING. The only purpose seems to
* allow drivers/soc/fsl/qbman/qman_portal.c to do
* fsl_pamu_configure_l1_stash()
*/
The logic hasn't really been touched in 10 years.
--
Ben Collins
https://libjwt.io
https://github.com/benmcollins
--
3EC9 7598 1672 961A 1139 173A 5D5A 57C7 242B 22CF
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