iommu/vt-d: Use a helper function to skip agaw for SL

An Intel iommu domain uses 5-level page table by default. If the iommu
that the domain tries to attach supports less page levels, the top level
page tables should be skipped. Add a helper to do this so that it could
be used in other places.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20200516062101.29541-3-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Jacob Pan 2020-05-16 14:20:45 +08:00 committed by Joerg Roedel
parent 3db9983e43
commit 3aef9ca6a4

View File

@ -499,6 +499,25 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu,
return 0;
}
/*
* Skip top levels of page tables for iommu which has less agaw
* than default. Unnecessary for PT mode.
*/
static inline int iommu_skip_agaw(struct dmar_domain *domain,
struct intel_iommu *iommu,
struct dma_pte **pgd)
{
int agaw;
for (agaw = domain->agaw; agaw > iommu->agaw; agaw--) {
*pgd = phys_to_virt(dma_pte_addr(*pgd));
if (!dma_pte_present(*pgd))
return -EINVAL;
}
return agaw;
}
/*
* Set up the scalable mode pasid entry for second only translation type.
*/
@ -522,17 +541,11 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu,
return -EINVAL;
}
/*
* Skip top levels of page tables for iommu which has less agaw
* than default. Unnecessary for PT mode.
*/
pgd = domain->pgd;
for (agaw = domain->agaw; agaw > iommu->agaw; agaw--) {
pgd = phys_to_virt(dma_pte_addr(pgd));
if (!dma_pte_present(pgd)) {
dev_err(dev, "Invalid domain page table\n");
return -EINVAL;
}
agaw = iommu_skip_agaw(domain, iommu, &pgd);
if (agaw < 0) {
dev_err(dev, "Invalid domain page table\n");
return -EINVAL;
}
pgd_val = virt_to_phys(pgd);