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....@intel.com>
Cc: Jacob Pan <jacob.jun....@linux.intel.com>
Cc: Kevin Tian <kevin.t...@intel.com>
Signed-off-by: Sanjay Kumar <sanjay.k.ku...@intel.com>
Signed-off-by: Liu Yi L <yi.l....@intel.com>
Signed-off-by: Lu Baolu <baolu...@linux.intel.com>
Reviewed-by: Ashok Raj <ashok....@intel.com>
---
 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 e741238e2326..a077ff3f67a6 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2462,6 +2462,22 @@ static struct dmar_domain 
*dmar_insert_one_dev_info(struct intel_iommu *iommu,
                        dmar_remove_one_dev_info(domain, dev);
                        return NULL;
                }
+
+               /* Setup the PASID entry for requests without PASID: */
+               spin_lock(&iommu->lock);
+               if (hw_pass_through && domain_type_is_si(domain))
+                       ret = intel_pasid_setup_pass_through(iommu, domain,
+                                       dev, PASID_RID2PASID);
+               else
+                       ret = intel_pasid_setup_second_level(iommu, domain,
+                                       dev, PASID_RID2PASID);
+               spin_unlock(&iommu->lock);
+               if (ret) {
+                       pr_err("Setup RID2PASID for %s failed\n",
+                              dev_name(dev));
+                       dmar_remove_one_dev_info(domain, dev);
+                       return NULL;
+               }
        }
 
        if (dev && domain_context_mapping(domain, dev)) {
@@ -4825,6 +4841,10 @@ 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_entry(iommu, 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 3c70522091d3..d6f4fead4491 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

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