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

[Lu Baolu <baolu.lu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

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-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Jacob Pan <jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Cc: Kevin Tian <kevin.tian-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Liu Yi L <yi.l.liu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Lu Baolu <baolu.lu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 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 99c643b..d4f9cea 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5146,22 +5146,16 @@ 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)
@@ -5198,7 +5192,7 @@ 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