[PATCH v2 1/8] iommu: Assign per device max PASID

[Jacob Pan]

From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>

PCIe spec defines Max PASID Width per-device.  Since a PASID is only
used with IOMMU enabled, this patch introduces a PASID max variable on
the per-device IOMMU data. It will be used for limiting PASID allocation
in that PASID table is per-device.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
---
 drivers/iommu/intel/iommu.c |  4 +++-
 include/linux/iommu.h       | 13 +++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 50666d250b36..881f8361eca2 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2602,8 +2602,10 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 		if (sm_supported(iommu)) {
 			if (pasid_supported(iommu)) {
 				int features = pci_pasid_features(pdev);
-				if (features >= 0)
+				if (features >= 0) {
 					info->pasid_supported = features | 1;
+					iommu_set_dev_pasid_max(&pdev->dev, pci_max_pasids(pdev));
+				}
 			}
 
 			if (info->ats_supported && ecap_prs(iommu->ecap) &&
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index de0c57a567c8..369f05c2a4e2 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -364,6 +364,7 @@ struct iommu_fault_param {
  * @fwspec:	 IOMMU fwspec data
  * @iommu_dev:	 IOMMU device this device is linked to
  * @priv:	 IOMMU Driver private data
+ * @pasid_max	 Max PASID value supported by this device
  *
  * TODO: migrate other per device data pointers under iommu_dev_data, e.g.
  *	struct iommu_group	*iommu_group;
@@ -375,8 +376,20 @@ struct dev_iommu {
 	struct iommu_fwspec		*fwspec;
 	struct iommu_device		*iommu_dev;
 	void				*priv;
+	unsigned int			pasid_max;
 };
 
+static inline void iommu_set_dev_pasid_max(struct device *dev,
+					    unsigned int max)
+{
+	struct dev_iommu *param = dev->iommu;
+
+	if (WARN_ON(!param))
+		return;
+
+	param->pasid_max = max;
+}
+
 int iommu_device_register(struct iommu_device *iommu,
 			  const struct iommu_ops *ops,
 			  struct device *hwdev);
-- 
2.25.1