On Wed, Sep 24, 2014 at 09:34:26PM +0100, Mitchel Humpherys wrote: > On Wed, Sep 24 2014 at 09:37:12 AM, Will Deacon <[email protected]> wrote: > > On Wed, Sep 24, 2014 at 02:12:00AM +0100, Mitchel Humpherys wrote: > >> On Mon, Sep 22 2014 at 08:26:14 AM, Will Deacon <[email protected]> > >> wrote: > >> > On Thu, Sep 11, 2014 at 07:30:44PM +0100, Mitchel Humpherys wrote: > >> >> + return arm_smmu_iova_to_phys_soft(domain, iova); > >> >> + } > >> >> + > >> >> + phys = readl_relaxed(cb_base + ARM_SMMU_CB_PAR_LO); > >> >> + phys |= ((u64) readl_relaxed(cb_base + ARM_SMMU_CB_PAR_HI)) << > >> >> 32; > >> >> + > >> >> + if (phys & CB_PAR_F) { > >> >> + dev_err(dev, "translation fault on %s!\n", > >> >> dev_name(dev)); > >> >> + dev_err(dev, "PAR = 0x%llx\n", phys); > >> >> + } > >> >> + phys = (phys & 0xFFFFFFF000ULL) | (iova & 0x00000FFF); > >> > > >> > How does this work for 64k pages? > >> > >> So at the moment we're always assuming that we're using v7/v8 long > >> descriptor format, right? All I see in the spec (14.5.15 SMMU_CBn_PAR) > >> is that bits[47:12]=>PA[47:12]... Or am I missing something completely? > > > > I think you've got 64k pages confused with the short-descriptor format. > > > > When we use 64k pages with long descriptors, you're masked off bits 15-12 of > > the iova above, so you'll have a hole in the physical address afaict. > > Even with long descriptors the spec says bits 15-12 should come from > CB_PAR... It makes no mention of reinterpreting those bits depending on > the programmed page granule. The only thing I can conclude from the > spec is that hardware should be smart enough to do the right thing with > bits 15-12 when the page granule is 64k. Although even if hardware is > smart enough I guess CB_PAR[15:12] should be the same as iova[15:12] for > the 64k case?
Yeah, fair enough, the code you have should work correctly then. Unfortunately, I don't have any suitable hardware on which to test it. Will _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
