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authorJacob Pan <jacob.jun.pan@linux.intel.com>2016-12-06 21:14:23 +0300
committerJoerg Roedel <jroedel@suse.de>2017-01-04 17:18:57 +0300
commit65ca7f5f7d1cdde6c25172fe6107cd16902f826f (patch)
tree6fff0dccb8fcf28797336c23e973f7dfbd8a20a4 /drivers/iommu/intel-iommu.c
parentaec0e86172a79eb5e44aff1055bb953fe4d47c59 (diff)
downloadlinux-65ca7f5f7d1cdde6c25172fe6107cd16902f826f.tar.xz
iommu/vt-d: Fix pasid table size encoding
Different encodings are used to represent supported PASID bits and number of PASID table entries. The current code assigns ecap_pss directly to extended context table entry PTS which is wrong and could result in writing non-zero bits to the reserved fields. IOMMU fault reason 11 will be reported when reserved bits are nonzero. This patch converts ecap_pss to extend context entry pts encoding based on VT-d spec. Chapter 9.4 as follows: - number of PASID bits = ecap_pss + 1 - number of PASID table entries = 2^(pts + 5) Software assigned limit of pasid_max value is also respected to match the allocation limitation of PASID table. cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Tested-by: Mika Kuoppala <mika.kuoppala@intel.com> Fixes: 2f26e0a9c9860 ('iommu/vt-d: Add basic SVM PASID support') Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/intel-iommu.c')
-rw-r--r--drivers/iommu/intel-iommu.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 8862dc1e88eb..8a185250ae5a 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5204,6 +5204,25 @@ static void intel_iommu_remove_device(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)
+{
+ /*
+ * 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)
+ 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;
+}
+
int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev *sdev)
{
struct device_domain_info *info;
@@ -5236,7 +5255,9 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev *sd
if (!(ctx_lo & CONTEXT_PASIDE)) {
context[1].hi = (u64)virt_to_phys(iommu->pasid_state_table);
- context[1].lo = (u64)virt_to_phys(iommu->pasid_table) | ecap_pss(iommu->ecap);
+ context[1].lo = (u64)virt_to_phys(iommu->pasid_table) |
+ intel_iommu_get_pts(iommu);
+
wmb();
/* CONTEXT_TT_MULTI_LEVEL and CONTEXT_TT_DEV_IOTLB are both
* extended to permit requests-with-PASID if the PASIDE bit