From: Jacob Pan <jacob.jun.pan@linux.intel.com>
Date: Sat, 16 May 2020 14:20:45 +0800
Subject: iommu/vt-d: Use a helper function to skip agaw for SL
Git-commit: 3aef9ca6a42aca8c797f867e554ad297b446439f
Patch-mainline: v5.8-rc1
References: bsc#1175713
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>
---
drivers/iommu/intel-pasid.c | 33 +++++++++++++++++++++++----------
1 file changed, 23 insertions(+), 10 deletions(-)
diff --git a/drivers/iommu/intel-pasid.c b/drivers/iommu/intel-pasid.c
index 22b30f10b396..d9cea3011b58 100644
--- a/drivers/iommu/intel-pasid.c
+++ b/drivers/iommu/intel-pasid.c
@@ -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);