[PATCH v8 3/7] iommu/vt-d: Add domain_flush_pasid_iotlb()

[Jacob Pan <jacob.jun.pan@linux.intel.com>]

From: Lu Baolu <baolu.lu@linux.intel.com>

The VT-d spec requires to use PASID-based-IOTLB invalidation descriptor
to invalidate IOTLB and the paging-structure caches for a first-stage
page table. Add a generic helper to do this.

RID2PASID is used if the domain has been attached to a physical device,
otherwise real PASIDs that the domain has been attached to will be used.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
 drivers/iommu/intel/iommu.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 4eba9973f537..3214990b69b7 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1475,6 +1475,24 @@ static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
 	spin_unlock_irqrestore(&domain->lock, flags);
 }
 
+/*
+ * The VT-d spec requires to use PASID-based-IOTLB Invalidation to
+ * invalidate IOTLB and the paging-structure-caches for a first-stage
+ * page table.
+ */
+static void domain_flush_pasid_iotlb(struct intel_iommu *iommu,
+				     struct dmar_domain *domain, u64 addr,
+				     unsigned long npages, bool ih)
+{
+	u16 did = domain_id_iommu(domain, iommu);
+	unsigned long flags;
+
+	spin_lock_irqsave(&domain->lock, flags);
+	if (!list_empty(&domain->devices))
+		qi_flush_piotlb(iommu, did, IOMMU_NO_PASID, addr, npages, ih);
+	spin_unlock_irqrestore(&domain->lock, flags);
+}
+
 static void iommu_flush_iotlb_psi(struct intel_iommu *iommu,
 				  struct dmar_domain *domain,
 				  unsigned long pfn, unsigned int pages,
@@ -1492,7 +1510,7 @@ static void iommu_flush_iotlb_psi(struct intel_iommu *iommu,
 		ih = 1 << 6;
 
 	if (domain->use_first_level) {
-		qi_flush_piotlb(iommu, did, IOMMU_NO_PASID, addr, pages, ih);
+		domain_flush_pasid_iotlb(iommu, domain, addr, pages, ih);
 	} else {
 		unsigned long bitmask = aligned_pages - 1;
 
@@ -1562,7 +1580,7 @@ static void intel_flush_iotlb_all(struct iommu_domain *domain)
 		u16 did = domain_id_iommu(dmar_domain, iommu);
 
 		if (dmar_domain->use_first_level)
-			qi_flush_piotlb(iommu, did, IOMMU_NO_PASID, 0, -1, 0);
+			domain_flush_pasid_iotlb(iommu, dmar_domain, 0, -1, 0);
 		else
 			iommu->flush.flush_iotlb(iommu, did, 0, 0,
 						 DMA_TLB_DSI_FLUSH);
-- 
2.25.1