[PATCH v1 2/9] iommu/vt-d: Add helpers for domain mapping/unmapping

From: Lu Baolu
Date: Tue Mar 12 2019 - 02:06:00 EST


This adds two helpers to map or unmap a physically
contiguous memory region in the page table of an
iommu domain.

Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Tested-by: Xu Pengfei <pengfei.xu@xxxxxxxxx>
Tested-by: Mika Westerberg <mika.westerberg@xxxxxxxxx>
---
drivers/iommu/intel-iommu.c | 35 +++++++++++++++++++++++++++++++++++
include/linux/intel-iommu.h | 5 +++++
2 files changed, 40 insertions(+)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 7b433772bce0..791261afb4a9 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5847,3 +5847,38 @@ static void __init check_tylersburg_isoch(void)
pr_warn("Recommended TLB entries for ISOCH unit is 16; your BIOS set %d\n",
vtisochctrl);
}
+
+/*
+ * Map a physically contiguous memory region in the dma page table
+ * of an iommu domain.
+ */
+int
+domain_iomap_range(struct dmar_domain *domain, unsigned long addr,
+ phys_addr_t paddr, size_t size, int prot)
+{
+ return domain_mapping(domain,
+ mm_to_dma_pfn(IOVA_PFN(addr)),
+ NULL,
+ mm_to_dma_pfn(IOVA_PFN(paddr)),
+ aligned_nrpages(addr, size),
+ prot);
+}
+
+/*
+ * Unmap a physically contiguous memory region in the dma page table
+ * of an iommu domain. Return the free page list that should be freed
+ * after iotlb flush. We can't free these pages here since it possibly
+ * is still used by iotlb cache for a DMA translation.
+ */
+struct page *
+domain_iounmap_range(struct dmar_domain *domain, unsigned long addr,
+ size_t size)
+{
+ unsigned long nrpages, start_pfn, last_pfn;
+
+ nrpages = aligned_nrpages(addr, size);
+ start_pfn = mm_to_dma_pfn(IOVA_PFN(addr));
+ last_pfn = start_pfn + nrpages - 1;
+
+ return domain_unmap(domain, start_pfn, last_pfn);
+}
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 6925a18a5ca3..74afedfe193b 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -663,6 +663,11 @@ int for_each_device_domain(int (*fn)(struct device_domain_info *info,
void iommu_flush_write_buffer(struct intel_iommu *iommu);
int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev);

+int domain_iomap_range(struct dmar_domain *domain, unsigned long addr,
+ phys_addr_t paddr, size_t size, int prot);
+struct page *domain_iounmap_range(struct dmar_domain *domain,
+ unsigned long addr, size_t size);
+
#ifdef CONFIG_INTEL_IOMMU_SVM
int intel_svm_init(struct intel_iommu *iommu);
extern int intel_svm_enable_prq(struct intel_iommu *iommu);
--
2.17.1