[PATCH v3 4/6] iommu/vt-d: Setup pasid entries for iova over first level

[Lu Baolu]

Intel VT-d in scalable mode supports two types of page tables for
IOVA translation: first level and second level. The IOMMU driver
can choose one from both for IOVA translation according to the use
case. This sets up the pasid entry if a domain is selected to use
the first-level page table for iova translation.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
 drivers/iommu/intel-iommu.c | 48 +++++++++++++++++++++++++++++++++++--
 include/linux/intel-iommu.h | 10 ++++----
 2 files changed, 52 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 2b5a47584baf..83a7abf0c4f0 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -571,6 +571,11 @@ static inline int domain_type_is_si(struct dmar_domain *domain)
 	return domain->flags & DOMAIN_FLAG_STATIC_IDENTITY;
 }
 
+static inline bool domain_use_first_level(struct dmar_domain *domain)
+{
+	return domain->flags & DOMAIN_FLAG_USE_FIRST_LEVEL;
+}
+
 static inline int domain_pfn_supported(struct dmar_domain *domain,
 				       unsigned long pfn)
 {
@@ -2288,6 +2293,8 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
 		return -EINVAL;
 
 	prot &= DMA_PTE_READ | DMA_PTE_WRITE | DMA_PTE_SNP;
+	if (domain_use_first_level(domain))
+		prot |= DMA_FL_PTE_PRESENT;
 
 	if (!sg) {
 		sg_res = nr_pages;
@@ -2515,6 +2522,36 @@ dmar_search_domain_by_dev_info(int segment, int bus, int devfn)
 	return NULL;
 }
 
+static int domain_setup_first_level(struct intel_iommu *iommu,
+				    struct dmar_domain *domain,
+				    struct device *dev,
+				    int pasid)
+{
+	int flags = PASID_FLAG_SUPERVISOR_MODE;
+	struct dma_pte *pgd = domain->pgd;
+	int agaw, level;
+
+	/*
+	 * Skip top levels of page tables for iommu which has
+	 * less agaw than default. Unnecessary for PT mode.
+	 */
+	for (agaw = domain->agaw; agaw > iommu->agaw; agaw--) {
+		pgd = phys_to_virt(dma_pte_addr(pgd));
+		if (!dma_pte_present(pgd))
+			return -ENOMEM;
+	}
+
+	level = agaw_to_level(agaw);
+	if (level != 4 && level != 5)
+		return -EINVAL;
+
+	flags |= (level == 5) ? PASID_FLAG_FL5LP : 0;
+
+	return intel_pasid_setup_first_level(iommu, dev, (pgd_t *)pgd, pasid,
+					     domain->iommu_did[iommu->seq_id],
+					     flags);
+}
+
 static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 						    int bus, int devfn,
 						    struct device *dev,
@@ -2614,6 +2651,9 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 		if (hw_pass_through && domain_type_is_si(domain))
 			ret = intel_pasid_setup_pass_through(iommu, domain,
 					dev, PASID_RID2PASID);
+		else if (domain_use_first_level(domain))
+			ret = domain_setup_first_level(iommu, domain, dev,
+					PASID_RID2PASID);
 		else
 			ret = intel_pasid_setup_second_level(iommu, domain,
 					dev, PASID_RID2PASID);
@@ -5369,8 +5409,12 @@ static int aux_domain_add_dev(struct dmar_domain *domain,
 		goto attach_failed;
 
 	/* Setup the PASID entry for mediated devices: */
-	ret = intel_pasid_setup_second_level(iommu, domain, dev,
-					     domain->default_pasid);
+	if (domain_use_first_level(domain))
+		ret = domain_setup_first_level(iommu, domain, dev,
+					       domain->default_pasid);
+	else
+		ret = intel_pasid_setup_second_level(iommu, domain, dev,
+						     domain->default_pasid);
 	if (ret)
 		goto table_failed;
 	spin_unlock(&iommu->lock);
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index aaece25c055f..66b525bad434 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -34,10 +34,12 @@
 #define VTD_STRIDE_SHIFT        (9)
 #define VTD_STRIDE_MASK         (((u64)-1) << VTD_STRIDE_SHIFT)
 
-#define DMA_PTE_READ (1)
-#define DMA_PTE_WRITE (2)
-#define DMA_PTE_LARGE_PAGE (1 << 7)
-#define DMA_PTE_SNP (1 << 11)
+#define DMA_PTE_READ		(1)
+#define DMA_PTE_WRITE		(2)
+#define DMA_PTE_LARGE_PAGE	(1 << 7)
+#define DMA_PTE_SNP		(1 << 11)
+
+#define DMA_FL_PTE_PRESENT	(1)
 
 #define CONTEXT_TT_MULTI_LEVEL	0
 #define CONTEXT_TT_DEV_IOTLB	1
-- 
2.17.1