[PATCH 4/4] iommu/vt-d: Enable 5-level paging mode in the PASID entry

[Sohil Mehta <sohil.mehta-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

If the CPU has support for 5-level paging enabled and the IOMMU also
supports 5-level paging then enable the 5-level paging mode for first-
level translations - used when SVM is enabled.

Signed-off-by: Sohil Mehta <sohil.mehta-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/iommu/intel-svm.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 4072a18..d7095dd 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -26,6 +26,10 @@
 #include <linux/interrupt.h>
 #include <asm/page.h>
 
+#define PASID_ENTRY_P		BIT_ULL(0)
+#define PASID_ENTRY_FLPM_5LP	BIT_ULL(9)
+#define PASID_ENTRY_SRE		BIT_ULL(11)
+
 static irqreturn_t prq_event_thread(int irq, void *d);
 
 struct pasid_entry {
@@ -297,6 +301,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
 	struct intel_svm_dev *sdev;
 	struct intel_svm *svm = NULL;
 	struct mm_struct *mm = NULL;
+	u64 pasid_entry_val;
 	int pasid_max;
 	int ret;
 
@@ -403,9 +408,15 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
 				kfree(sdev);
 				goto out;
 			}
-			iommu->pasid_table[svm->pasid].val = (u64)__pa(mm->pgd) | 1;
+			pasid_entry_val = (u64)__pa(mm->pgd) | PASID_ENTRY_P;
 		} else
-			iommu->pasid_table[svm->pasid].val = (u64)__pa(init_mm.pgd) | 1 | (1ULL << 11);
+			pasid_entry_val = (u64)__pa(init_mm.pgd) |
+					  PASID_ENTRY_P | PASID_ENTRY_SRE;
+		if (cpu_feature_enabled(X86_FEATURE_LA57))
+			pasid_entry_val |= PASID_ENTRY_FLPM_5LP;
+
+		iommu->pasid_table[svm->pasid].val = pasid_entry_val;
+
 		wmb();
 		/* In caching mode, we still have to flush with PASID 0 when
 		 * a PASID table entry becomes present. Not entirely clear
-- 
2.7.4