On Tue, Apr 22, 2025 at 08:43:05PM -0500, Jason Gunthorpe wrote: > On Tue, Apr 22, 2025 at 06:21:32PM -0400, Ben Collins wrote: > > 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: > > Yes, I know, but you are changing this - are you changing it because > something is broken without making this change, if so what, or are you > changing it because it looked like it needed changing? > > > The logic hasn't really been touched in 10 years. > > Yeah, so I'm surprised someone still cares about it :)
Ironically, this patch sat collecting dust for 10 years until recently when I revived my T4240 system :) The change is mostly to be "correct" in as much as the code can be correct when it's a little broken. Does it fix anything? It does. PAMU gets a little miffed about my liodn tags being up near the 1TiB boundary. If it makes you feel any better about it, I've added fsl_pamu to the list of things I'm fixing for this board, for the hell of it. I have a pex8724 to program to get 2 of the 4 nvme slots up, a DPAA driver to build to get the RIO up (and likely some tweaking to program the IDT SRIO switch to work across the fabric). IOW, I think I can maybe help get rid of your FIXMEs. For reference: https://www.manualslib.com/manual/1061198/Vvdn-T4mfcs-Scaleout.html Plus I have a couple P4080 systems for regression testing with a 36-bit addressing space. -- Ben Collins https://libjwt.io https://github.com/benmcollins -- 3EC9 7598 1672 961A 1139 173A 5D5A 57C7 242B 22CF
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