[PATCH v2 7/9] iommu/vt-d: Calculate PTS value

From: Lu Baolu
Date: Thu May 03 2018 - 21:51:39 EST


Calculate PTS (PASID Table Size) value for the extended
context entry from the real size of the PASID table for
a domain.

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: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Reviewed-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
---
drivers/iommu/intel-iommu.c | 22 ++++++++--------------
1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index f86302d..5602ccd 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5152,22 +5152,16 @@ static void intel_iommu_put_resv_regions(struct device *dev,

#ifdef CONFIG_INTEL_IOMMU_SVM
#define MAX_NR_PASID_BITS (20)
-static inline unsigned long intel_iommu_get_pts(struct intel_iommu *iommu)
+static inline unsigned long intel_iommu_get_pts(struct dmar_domain *domain)
{
- /*
- * Convert ecap_pss to extend context entry pts encoding, also
- * respect the soft pasid_max value set by the iommu.
- * - number of PASID bits = ecap_pss + 1
- * - number of PASID table entries = 2^(pts + 5)
- * Therefore, pts = ecap_pss - 4
- * e.g. KBL ecap_pss = 0x13, PASID has 20 bits, pts = 15
- */
- if (ecap_pss(iommu->ecap) < 5)
+ int pts;
+
+ pts = find_first_bit((unsigned long *)&domain->max_pasid,
+ MAX_NR_PASID_BITS);
+ if (pts < 5)
return 0;

- /* pasid_max is encoded as actual number of entries not the bits */
- return find_first_bit((unsigned long *)&iommu->pasid_max,
- MAX_NR_PASID_BITS) - 5;
+ return pts - 5;
}

int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev *sdev)
@@ -5204,7 +5198,7 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev *sd
if (iommu->pasid_state_table)
context[1].hi = (u64)virt_to_phys(iommu->pasid_state_table);
context[1].lo = (u64)virt_to_phys(iommu->pasid_table) |
- intel_iommu_get_pts(iommu);
+ intel_iommu_get_pts(domain);

wmb();
/* CONTEXT_TT_MULTI_LEVEL and CONTEXT_TT_DEV_IOTLB are both
--
2.7.4