From 3aef9ca6a42aca8c797f867e554ad297b446439f Mon Sep 17 00:00:00 2001 From: Jacob Pan Date: Sat, 16 May 2020 14:20:45 +0800 Subject: [PATCH] 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 Signed-off-by: Lu Baolu Reviewed-by: Eric Auger Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20200516062101.29541-3-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- 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 22b30f1..d9cea30 100644 --- a/drivers/iommu/intel-pasid.c +++ b/drivers/iommu/intel-pasid.c @@ -500,6 +500,25 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu, } /* + * 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. */ int intel_pasid_setup_second_level(struct intel_iommu *iommu, @@ -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); -- 2.7.4