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

Jacob Pan
2022-03-15T05:11:12Z

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

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@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
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