[PATCH v3 07/12] iommu/vt-d: Setup pasid entry for RID2PASID support

[Lu Baolu]

when the scalable mode is enabled, there is no second level
page translation pointer in the context entry any more (for
DMA request without PASID). Instead, a new RID2PASID field
is introduced in the context entry. Software can choose any
PASID value to set RID2PASID and then setup the translation
in the corresponding PASID entry. Upon receiving a DMA request
without PASID, hardware will firstly look at this RID2PASID
field and then treat this request as a request with a pasid
value specified in RID2PASID field.

Though software is allowed to use any PASID for the RID2PASID,
we will always use the PASID 0 as a sort of design decision.

Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
Cc: Liu Yi L <yi.l.liu@xxxxxxxxx>
Signed-off-by: Sanjay Kumar <sanjay.k.kumar@xxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Reviewed-by: Ashok Raj <ashok.raj@xxxxxxxxx>
---
 drivers/iommu/intel-iommu.c | 20 ++++++++++++++++++++
 drivers/iommu/intel-pasid.h |  1 +
 2 files changed, 21 insertions(+)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index dac1296b3a5d..2762b076eee6 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2451,12 +2451,27 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 
 	/* PASID table is mandatory for a PCI device in scalable mode. */
 	if (dev && dev_is_pci(dev) && sm_supported(iommu)) {
+		bool pass_through;
+
 		ret = intel_pasid_alloc_table(dev);
 		if (ret) {
 			__dmar_remove_one_dev_info(info);
 			spin_unlock_irqrestore(&device_domain_lock, flags);
 			return NULL;
 		}
+
+		/* Setup the PASID entry for requests without PASID: */
+		pass_through = hw_pass_through && domain_type_is_si(domain);
+		spin_lock(&iommu->lock);
+		ret = intel_pasid_setup_second_level(iommu, domain, dev,
+						     PASID_RID2PASID,
+						     pass_through);
+		spin_unlock(&iommu->lock);
+		if (ret) {
+			__dmar_remove_one_dev_info(info);
+			spin_unlock_irqrestore(&device_domain_lock, flags);
+			return NULL;
+		}
 	}
 	spin_unlock_irqrestore(&device_domain_lock, flags);
 
@@ -4823,6 +4838,11 @@ static void __dmar_remove_one_dev_info(struct device_domain_info *info)
 	iommu = info->iommu;
 
 	if (info->dev) {
+		if (dev_is_pci(info->dev) && sm_supported(iommu))
+			intel_pasid_tear_down_second_level(iommu,
+					info->domain, info->dev,
+					PASID_RID2PASID);
+
 		iommu_disable_dev_iotlb(info);
 		domain_context_clear(iommu, info->dev);
 		intel_pasid_free_table(info->dev);
diff --git a/drivers/iommu/intel-pasid.h b/drivers/iommu/intel-pasid.h
index 85b158a1826a..dda578b8f18e 100644
--- a/drivers/iommu/intel-pasid.h
+++ b/drivers/iommu/intel-pasid.h
@@ -10,6 +10,7 @@
 #ifndef __INTEL_PASID_H
 #define __INTEL_PASID_H
 
+#define PASID_RID2PASID			0x0
 #define PASID_MIN			0x1
 #define PASID_MAX			0x100000
 #define PASID_PTE_MASK			0x3F
-- 
2.17.1